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  • 1985-1989  (516)
  • 1980-1984
  • 1987  (516)
  • Engineering  (448)
  • Gas chromatography
  • Nuclear reactions
  • Physics
  • 1
    Electronic Resource
    Electronic Resource
    Monoterpene hydrocarbon contents of the resin from seeds of silver fir (Abies alba Mill.) (1987)
    Springer
    Trees 1 (1987), S. 94-101 
    Details
    ISSN: 1432-2285
    Keywords: Monoterpenes ; Abies alba Mill ; Resin ; Seeds ; Gas chromatography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Using gas-chromatographic methods, the variability of the contents of monoterpene hydrocarbons (α-pinene, β-pinene, Δ3carene and limonene) in the resin of silver fir seeds (Abies alba Mill.) was studied. Resin cavities were characterized according to their position on the seed surface. It was estabilished that the terpene content of the resin of cavities localized on the abaxialadaxial surfaces of the seed differs significantly, creating a gradient of resin composition around the circumference of the seed. The differences between various resin cavities of single seeds were greater than the differences between different seeds of a single cone and between seeds of various cones on a single tree. An accurate definition of the resin cavity location on the seeds appears to be a fundamental condition for the collection of a sample representing the resin composition of individual trees. Resin biosynthesis in the course of organogenesis and the control of terpene contents in the resin of various locations on the seed and the cone are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00203577
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  • 2
    Electronic Resource
    Electronic Resource
    Plasma bile acids in patients with peroxisomal dysfunction syndromes: analysis by capillary gas chromatography — mass spectrometry (1987)
    Springer
    European journal of pediatrics 146 (1987), S. 166-173 
    Details
    ISSN: 1432-1076
    Keywords: Bile acids ; Gas chromatography ; Peroxisomal disorders
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Six patients with disorders of peroxisomal function have been studied. Two presented in the neonatal period with the classical features of the Zellweger syndrome, two had incomplete Zellweger phenotypes, one infantile Refsum's disease and one rhizomelic chondrodysplasia punctata. Plasma bile acid profiles were determined using capillary gas chromatography-mass spectrometry. In all patients, except the case of chondrodysplasia punctata, 27-carbon and 29-carbon bile acids were present. The compounds identified included trihydroxycoprostanic acid (THCA), dihydroxycoprostanic acid (DHCA), C24-, C25- and C26-hydroxylated derivatives of THCA, a 27-carbon acid with four nuclear hydroxy groups and 3α,7α,12α-trihydroxy-27a,27b-dihomo-5β-cholestan-26, 27b-dioic acid (C29-dicarboxylic acid). THCA was present at a low concentration in the patient with infantile Refsum's disease; the concentration of DHCA and the C29 dicarboxylic acid were considerably higher. The presence of abnormal bile acids in patients with Zellweger syndrome and infantile Refsum's disease could be explained by the absence of peroxisomes from their hepatocytes. In chondrodysplasia punctata the cause of peroxisomal dysfunction must be different, since normal bile acid synthesis is preserved.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02343226
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  • 3
    Electronic Resource
    Electronic Resource
    Serum alpha-tocopherol levels after high-dose enteral vitamin E administration in patients with acute respiratory failure (1987)
    Springer
    Intensive care medicine 13 (1987), S. 395-400 
    Details
    ISSN: 1432-1238
    Keywords: Acute respiratory distress syndrome ; Alpha-tocopherol ; Alpha-tocopherolquinone ; Gas chromatography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Serum levels of tocopherols were measured in 5 healthy volunteers and in 14 patients with acute respiratory failure before and after onset of high-dose enteral vitamin E administration. The initial alphatocopherol levels did not differ between both groups (12.1±2.7 μg/ml in the volunteers and 11.3±3.5 μg/ml in the patient; mean±SD). After oral administration of 1 g d,l-alpha-tocopherylacetate per day the serum levels more than doubled within 1 day and reached a plateau between 22 and 30 μg/ml after 3 days in the volunteers. In contrast, application of even 3 g vitamin E/day by gastric tube in the patients with respiratory failure caused only a delayed increase of the serum levels with values nearly doubling after 5–10 days (6 patients), or there was no increase at all (8 patients). Serum alpha-tocopherol did not rise in patients without accompanying highmolecular weight formula diet and in patients with prolonged hemodynamic insufficiency and metabolic acidosis. The age of the patients, the fact of severe blood losses, hemodialysis and hemofiltration and the final out-come of death or survival appeared to be without influence on the response to enteral vitamin application. Neither in the volunteers nor in the patients with acute respiratory failure were there any detectable amounts of beta-, gamma- or delta-tocopherol or of alphatocopherolquinone or alpha-tocotrienol.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00257683
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  • 4
    Electronic Resource
    Electronic Resource
    Gas chromatographic analysis of aromatic carboxylic acids in the presence of C1−C22 fatty acids and C2−C16 dicarboxylic acids esterified in aqueous solutions as the n-propyl esters (1987)
    Springer
    Chromatographia 23 (1987), S. 925-928 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Esterification in aqueous solution ; n-Propyl esters of aromatic polycarboxylic acids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The direct esterification and gas chromatographic analysis of aromatic carboxylic acids as n-propyl esters is described. Derivatization is performed in aqueous solution with n-propanol in the presence of sulfuric acid. The n-propyl esters of benzoic, phthalic, trimellitic and pyromellitic acids permit their gas chromatographic separation from each other and from fatty acids and aliphatic dicarboxylic acids. At mode ratios of [H2O]/[n-PrOH]≤0.03 the water present does not interfere with the esterification reaction. At mole ratios above 0.03 anhydrous sodium sulfate is used for binding the water, at mole ratios of [Na2SO4anh.]/[H2O]=0.51–1.52 and of [H2SO4]/[Na2SO4anh.]=0.43–1.28, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02261472
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  • 5
    Electronic Resource
    Electronic Resource
    Capillary columns in series for the gas chromatographic analysis of essential oils (1987)
    Springer
    Chromatographia 23 (1987), S. 790-795 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Capillary columns in series ; Variable polarity columns ; Essential oils analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary By connecting capillary columns of different polarity in series and by changing the temperature program gradient, a system of variable polarity is obtained. The working conditions can be adjusted to optimize separations of complex mixtures. Application to the analysis of essential oils of: lavender, thyme, lemon petit grain, bergamot, and tangerine, are reported.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02311401
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  • 6
    Electronic Resource
    Electronic Resource
    Trace analysis of volatile polar organics by direct aqueous injection gas chromatography (1987)
    Springer
    Chromatographia 23 (1987), S. 273-278 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Aqueous samples ; Direct injection ; Traces of ketones and halogenated hydrocarbons ; Environmental analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Procedures for the quantitative analysis of industrial effluents which involve concentration by solvent extraction or the purge-and-trap method are time-consuming, labor-intensive, and prone to error. Direct aqueous injection gas chromatography using an electron-capture detector for the analysis of volatile halocarbons at the ppb level is in routine use in many laboratories. We now discuss the development of a similar protocol for the analysis of volatile polar organics such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and tretrahydrofuran using a flame-ionization detector.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02311779
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  • 7
    Electronic Resource
    Electronic Resource
    Use of backflushing and peak-cutting technique in gas chromatographic trace analysis (1987)
    Springer
    Chromatographia 23 (1987), S. 566-570 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Backflushing, peak-cutting technique ; Trace analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A backflusing, peak-cutting method was developed for the analysis of trace components present in the tail of a major component peak. Using a helium-ionization detector, the minimum detectable concentration (MDC) was: oxygen in hydrogen, 0.5ppm; nitrogen in oxygen or argon, 1ppm; and methane and carbon monoxide in nitrogen, 1ppm. The corresponding MDC values for the conventional single-column method were 7.2ppm, 8.3ppm, and 14 and 5ppm, respectively. Equations used to predict the retention time are given. The accuracy of the predicted retention time is about two percent compared to experimental results.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02324865
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  • 8
    Electronic Resource
    Electronic Resource
    Analysis of the metal-catalyzed decomposition of γ- and δ-haloesters by GC/FT-IR (1987)
    Springer
    Chromatographia 23 (1987), S. 547-552 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; FT-IR detection ; γ- and δ-Haloesters
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The decomposition of γ- and δ-haloesters has previously been observed to take place within a commercial GC/FT-IR light-pipe system. Using a home-built light-pipe interface, an analysis of this same class of compounds was conducted from which the source of the decomposition was determined to be a brass fitting central to the commercial system's assembly. It is proposed that the reaction is due to a weakening of the carbon-halogen bond by metal interaction thereby allowing lactonization to occur.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02324861
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  • 9
    Electronic Resource
    Electronic Resource
    Gas chromatographic retention indices for C6 alkanols on OV-101 and Carbowax 20M capillary columns (1987)
    Springer
    Chromatographia 23 (1987), S. 50-52 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Retention indices ; C6 alkanols ; OV-101 ; Carbowax 20M
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Gas chromatographic retention indices for 16 C6 alkanols measured on capillary columns coated with OV-101 methylsilicone and Carbowax 20M propylethyleneglycol liquid phases at 80° and 90°C were determined. The respective standard deviation values were 0.5 and 0.8 i.u. The correlation between the retention indices measured on non-polar and polar stationary phases and the boiling points of the alkanols was studied.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02310419
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  • 10
    Electronic Resource
    Electronic Resource
    Analysis of anesthetic gas mixtures of halothane, nitrous oxide and oxygen by gas chromatography (1987)
    Springer
    Chromatographia 23 (1987), S. 53-54 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Dual-column system ; Thermal conductivity detector ; Anesthetic gas mixtures
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A simple dual-column system with a thermal conductivity detector is described, that can be used for the quantitative analysis of anesthetic gas mixtures of halothane (2-bromo-2-chloro-1,1,1-trifluoroethane), nitrous oxide and oxygen. The separation was performed on a Carbopack (SP 1000) column and a Porapak Q column arranged in series across the detector.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02310420
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  • 11
    Electronic Resource
    Electronic Resource
    Selective sampling and capillary gas chromatography in the analysis of essential oils (1987)
    Springer
    Chromatographia 23 (1987), S. 818-824 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Selective sampling ; On-line fractionation ; Essential oil analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The paper describes the possibilities of on-line selective sampling as an on-line fraction technique for the analysis of essential oils. Selective sampling is a micro-separation method, on-line with on-column injection, carried out directly in the syringe body by means of a selective elution of the sample through a fraction cartridge. The paper reports a method of both preparing and standardizing silica gel cartridges, and illustrates through some examples the results of some elution series of solvents on different essential oils.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02311406
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  • 12
    Electronic Resource
    Electronic Resource
    Advances in the determination of volatile organic solvents and other organic pollutants by gas chromatography with thermal desorption sampling and injection (1987)
    Springer
    Chromatographia 23 (1987), S. 856-860 
    Details
    ISSN: 1612-1112
    Keywords: Organic pollutants determination ; Gas chromatography ; Thermal desorption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The problem of the separation of 34 volatile organic chlorinated compounds is solved by using three different GC columns selected according to the needs of the particular separation required. The effect of water vapor contained as moisture in the trapped air on the retention of some characteristic compounds is studied. The influence of dead volumes on trap injection is also studied.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02311413
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  • 13
    Electronic Resource
    Electronic Resource
    Calculation of retention indices in temperature-programmed gas chromatography (1987)
    Springer
    Chromatographia 23 (1987), S. 888-892 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Calculation of temperature programmed ; Retention indices
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A new method is presented for the calculation of the retention indices under linear temperature programming with or without an initial isothermal period. The data calculated by the method are in good agreement with the isothermal retention indices.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02261466
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  • 14
    Electronic Resource
    Electronic Resource
    Immobilization of silicone stationary phases on supports using ozone (1987)
    Springer
    Chromatographia 23 (1987), S. 169-170 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Packed column ; Immobilized silicone stationary phases ; Ozonization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Immobilization of silicone stationary phases, OV-1701 vinyl and OV-225 vinyl, on Chromosorb W-AW support was achieved in a simple procedure using ozone as an initiator. A column efficiency of 2400 theoretical plates/meter was obtained.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02311474
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  • 15
    Electronic Resource
    Electronic Resource
    New stationary phase polarity parameters considering the electric intermolecular interactions in gas chromatographic column (1987)
    Springer
    Chromatographia 23 (1987), S. 195-198 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Structure-retention relationships ; Polarity parameters ; Retention index
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The possibility of evaluation of the parameters representing the dispersive solute-solvent interactions is presented. BN and Bs values can be used to describe the liquid phase polarity and to predict the retention indices of alcohols when the model polyxyethylene glycol dialkyl ethers and their sulphur analogs are used as stationary phases. The possibility of the first ionization potentials estimation is also presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02311479
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  • 16
    Electronic Resource
    Electronic Resource
    Lipids of contemporary stillingia oil (1987)
    Springer
    Chromatographia 23 (1987), S. 240-242 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Stillingia oil ; Quantitative lipid analysis ; Chinese tallow,Sapium sebiferum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Contemporary stillingia oil from China is qualitatively similar to the oil described earlier, but it exhibits significant quantitative differences reflecting a degree of autoxidation of the unsaturated fatty acids either before or after crushing of the seeds.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02311771
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  • 17
    Electronic Resource
    Electronic Resource
    Investigation of interactions between chloroderivatives of alkanes and alkenes and chemically bonded transition metal complexes by gas chromatography (1987)
    Springer
    Chromatographia 23 (1987), S. 261-264 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Chemically bonded phases ; Specific interactions ; Chloroderivatives of alkanes and alkenes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Interactions of Cu(II) complexes chemically bonded to the surface of silica with chloro-derivatives of alkanes and alkenes were investigated. It was found that chlorine as a substituent exerts a considerable influence on the retention of the individual chloro-derivatives. In the case of chloroalkenes this influence is negative while in the case of chloroalkanes it is positive. The magnitude of the observed effect depends on the number of substituents and on the way of their distribution within the molecule.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02311776
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  • 18
    Electronic Resource
    Electronic Resource
    A polar macroporous sorbent for gas chromatography (1987)
    Springer
    Chromatographia 23 (1987), S. 286-288 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Macroporous copolymers of 2-hydroxyethyl ; methacrylate ; Graft polymers ; Polar sorbent for gas chromatography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The gas chromatographic behaviour of crosslinked macroporous 2-hydroxyethyl methacrylate grafted with 2-methyloxazoline was investigated and the range of applicability of the copolymer was assessed. Retention index values were measured on this copolymer and compared with those obtained on the terpolymer 2-hydroxyethyl methacrylate-ethylene dimethacrylate-acrylonitrile. Rohrschneider constants and efficiency data for selected sorbates are given. The use of this type of polymer in the separation of various types of compounds is documented by various examples.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02311781
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  • 19
    Electronic Resource
    Electronic Resource
    GC investigation of olefins with chemically bonded gamma-mercaptopropylsilane-copper(II) complexes (1987)
    Springer
    Chromatographia 23 (1987), S. 423-426 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Complexation ; Mercaptosilane chemically bonded phase ; Transition metal complexes ; Olefinic π-complexes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A column packing containing thiol groups chemically bonded to the silica surface was synthesized. The thiol functional groups were used as ligands capable of forming stable complexes with Cu(II). The prepared material was characterized by gas chromatography using unsaturated linear and branched hydrocarbons as well as cyclic and aromatic hydrocarbons. The occurrence of specific metal—olefin interactions resulting from the formation of π-complexes during the chromatographic process was observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02311818
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  • 20
    Electronic Resource
    Electronic Resource
    A new type of two-dimensional packed+capillary column GC system. III. Instrumentation (1987)
    Springer
    Chromatographia 23 (1987), S. 499-501 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Packed+capillary GC switching system ; Precolumn construction, oven and connector
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The constractional details of precolumns, its oven and connector have been given with two types of multiflow control modules. Two types of phases made in China, a silanized pellicular beads and a non silanized pellicular silica beads, with an optimum particle size of 20μm to 30μm were packed in the precolumn 20mm in length with the column efficiency of 4620 plates/meter at column temperature of 49°C. A 25m×0.22mm i.d. capillary column coated with bonded methylsilicone phase from Chrompack connected with the precolumn (250°C) has an efficiency of 5376 plates/meter for n-octane. But it decreased to 3149 plates/meter by decreasing the precolumn temperature to 130°C.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02309418
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  • 21
    Electronic Resource
    Electronic Resource
    Using discriminant analysis to estimate linear mixing proportions (1987)
    New York, NY : Wiley-Blackwell
    Journal of Chemometrics 1 (1987), S. 157-173 
    Details
    ISSN: 0886-9383
    Keywords: Gas chromatography ; Simplex ; Barycentric co-ordinates ; Discriminant analysis ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: This paper proposes an elegant, yet straightforward, model for classifying linear mixtures. A linear mixture is defined as a random vector y in which the variable are a (non-negative) weighted average of corresponding variables, assumed to characterize g component groups. These weights are referred to as ‘mixing proportions’. The model seeks to identify the mixture constituents and estimate the mixing proportions. It is demonstrated within the context of high resolution gas chromatography and the problem of identifying the constituents in polychlorinated biphenyl mixtures.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cem.1180010304
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  • 22
    Electronic Resource
    Electronic Resource
    A contribution to high-temperature silylation (1987)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 10 (1987), S. 158-159 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary columns ; Silylation ; Critical surface tension ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240100313
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  • 23
    Electronic Resource
    Electronic Resource
    Improved heat-shrinkable PTFE joints also for thin capillaries (1987)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 10 (1987), S. 156-157 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary columns ; Polytetrafluoroethylene (PTFE) joints ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240100312
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  • 24
    Electronic Resource
    Electronic Resource
    Collection of gas chromatographic fractions for NMR analysis (1987)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 10 (1987), S. 213-214 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Cryogenic trapping ; NMR analysis ; Flavor and aroma analysis ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240100414
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  • 25
    Electronic Resource
    Electronic Resource
    Sample introduction in high speed capillary gas chromatography; input band width and detection limits (1987)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 10 (1987), S. 273-279 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary columns ; High speed capillary GC ; Sample introduction ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The speed of analysis in capillary gas chromatography can be substantially increased by reduction of the column inner diameter. However, special demands are then posed upon instrumental design. In particular, the sampling system is highly critical because it has to be capable of delivering extremely small injection band widths which must be compatible with the column inside diameter. This study focuses on the evaluation of two potentially suitable sample introduction systems with respect to input band width and detection limits and their compatibility with small bore (≦ 100 μm) columns in capillary gas chromatography. One of them allows liquid on-column injection, based on liquid splitting, of only a few nl onto small bore (≦ 100 ◂m) fused silica columns. For gases, input band widths as low as 1 ms are obtained with this system. The other one is part of a miniaturized gas chromatograph with extremely low dead volume interfaces and detector volumes. It allows input band widths for gases of a few ms. Without any preconcentration ppm concentrations are measured in gaseous samples with a 80 ◂m thick film capillary column. It will be shown that a further reduction of the minimum detectable amount and analysis time is possible with this equipment.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240100512
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  • 26
    Electronic Resource
    Electronic Resource
    A simple and efficient cryogenic trapping device for odor evaluation of aroma fractions (1987)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 10 (1987), S. 369-370 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Cryogenic effluent trap ; Odor evaluation ; Aroma fractions ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240100613
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  • 27
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    Comparison of methods to enhance flame ionization detector (FID) signals in gas chromatography (1987)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 10 (1987), S. 392-397 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; FID signals ; Signal handling ; Signal enhancing ; Data acquisition ; Smoothing filtering correlation ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The performances of some numerical methods to improve the signal to noise ratio are compared and applied to enhance noisy signals obtained in gas chromatography with capillary columns and a flame Ionization detector. Several methods have been considered: cutoffs In the Fourier transform of the recorded signal; real time numerical filtering; theoretical model curve fitting; and the correlation of a chromatogram recorded from a pseudorandomly injected sample with the pseudorandom injection function. Numerical real time filtering is shown to be the most convenient method when the main periodic component of the noise has been determined by Fourier analysis.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240100705
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    Electronic Resource
    Analysis of three aminonitropyrene isomers via fused silica gas chromatography combined with negative ion atmospheric pressure ionization mass spectrometry (1987)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 10 (1987), S. 43-45 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Mass spectrometry ; Capillary GC ; Fused silica GC ; Nitro-PAHs ; Aminonitropyrene ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240100110
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  • 29
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    Electronic Resource
    Trace analysis of complex organic mixtures using capillary gas-liquid chromatography and the dynamic solvent effect (1987)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 10 (1987), S. 122-127 
    Details
    ISSN: 0935-6304
    Keywords: Trace analysis ; Gas chromatography ; Solvent effect ; Inlet ; Injector ; Sampling ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A sampling system for high resolution gas-liquid chromatography, based on the dynamic solvent effect, is described. Volatiles are accumulated off-line in a concentrator/injector and delivered to the column using an on-line inlet. Volatiles may be accumulated from gaseous or liquid matrices; they may be transferred to these by gas sparging or solvent extraction of any type of sample. The sampling technique is quantitatively precise; e.g. coefficients of variation of peak percentage areas better than 5% for a range of solutes at a concentration of 2:107. Examples of the application of the sampling system are presented.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240100304
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    Electronic Resource
    Determination of amino acids by gas chromatography using a wide bore capillary column (1987)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 10 (1987), S. 383-387 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Wide bore glass capillary ; Fused-silica capillary ; Component discrimination ; Butt connectors ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A procedure is described in which a wide bore capillary column is used as an alternative to the more traditional packed column for the quantitative analysis of amino acids as their N-heptafluorobutyryl isobutyl ester (HBB) derivatives. The column, installed in a gas chromatograph previously configured for use with a packed column, is shown to give good reproducibility by repeated determination of amino acid response factors (RSD values for all amino acids are below 3%). A number of problems, encountered during the use of this column, are discussed and suitable techniques to overcome them are reported.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240100703
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    Purging directly to a capillary column with whole column cryotrapping (P/WCC) for the determination of aqueous volatile compounds (1987)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 10 (1987), S. 409-410 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary GC ; Mass spectrometry ; Purge and trap ; Purge with whole column cryotrapping ; Whole column cryotrapping ; Purgeable compound determination ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240100709
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  • 32
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    Electronic Resource
    Kováts retention indices of selected mono and polycyclic olefins (1987)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 10 (1987), S. 461-463 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Mono and polycyclic olefins ; Retention index data ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240100809
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  • 33
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    Improved simulated distillation technique for characterization of heavy oils (1987)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 10 (1987), S. 479-480 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Megabore columns ; Simulated distillation ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240100816
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  • 34
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    Gas chromatography of volatile fatty acids as tert-butyidimethylsilyl esters (1987)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 10 (1987), S. 522-523 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Volatile fatty acids ; tert-Butyldimethylsilyl esters ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240100910
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    Electronic Resource
    Selective water removal in purge/GC analysis of volatile aromatics in aqueous samples (1987)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 10 (1987), S. 573-575 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary columns ; Cryogenic cooling ; Volatile aromatics ; Water removal ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240101012
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  • 36
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    CGC-MS determination of mixtures of long chain aliphatic esters (1987)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 10 (1987), S. 594-597 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary ; Mass spectrometry ; Ion monitoring ; Wax esters ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A method is described for the determination of the acid and alcohol moieties in long chain wax esters. The co-eluting esters are differentiated by means of CGC-MS operating in the ion monitoring mode. The technique allows to detect ester components present in very low amounts in plant surface waxes.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240101103
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    On the influence of the solute sample size on temperature-programmed retention indices (1987)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 10 (1987), S. 603-606 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary columns ; Temperature-programmed retention indices ; Sample size ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The effect of the solute sample size on the measurement of temperature-programmed retention indices (ITP) has been studied on glass capillary columns with different stationary phases, film thicknesses, and temperature programs. The sample capacity of a solute is little affected by the parameters of temperature program, i. e. initial temperature and heating rate. However, it has been found that in a temperature programmed run, allowable sample sizes for high ITP values are lower than for low ITP values. About 10 ng of each compound is recommended as the sample size for accurate measurement of ITP values on commonly used capillary columns.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240101105
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    Electronic Resource
    Modified inlet for injecting a bonded phase wide-bore fused silica capillary column with chlorinated pesticides in a lipid extract (1987)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 10 (1987), S. 620-622 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary GC ; Fused silica ; Wide-bore ; Direct flash vaporization ; Chlorinated pesticides ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240101108
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  • 39
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    Identification of mononitropyrenes and mononitrofluoranthenes in air particulate matter via fused silica gas, chromatography combined with negative ion atmospheric pressure ionization mass spectrometry (1987)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 10 (1987), S. 641-646 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Mass spectrometry ; Capillary GC ; Fused silica GC ; Nitro-PAHs ; Air particulate matter ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: This paper describes the use of high resolution capillary gas chromatography combined with negative ion atmospheric pressure ionization mass spectrometry (NIAPIMS) for the analysis of an air particulate extract for mononitropyrenes and mononitrofluoranthenes, some of which are powerful bacterial mutagens. The results are compared to those obtained by the electron impact mass spectrometric analysis of the same sample In addition, the NIAPIMS method confirmed the identification of 4-nitropyrene in the ambient air sample.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240101204
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  • 40
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    An optimized gas chromatographic determination of priority pollutant phenols (1987)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 10 (1987), S. 647-649 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary columns, fused silica ; Priority pollutant phenols ; Internal standard quantitation ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Priority pollutant phenols are determined by gas chromatography on an SE-30 WCOT column using hydrogen carrier and flame ionization detection with dual internal standards. Linear responses over ranges ca. 12-125 ng per component are achieved and detection limits at or below 1 ng are obtained. Carrier flow and temperature program are optimized to maintain baseline resolution while affording an analysis time of less than 15 minutes.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240101205
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  • 41
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    Preparation of inert glass capillary columns coated with UCON 50 HB-5100. An attempt to rediscover industrially produced α, ω-polyethylene/polypropyleneglycol ethers as stationary phases in capillary gas chromatography (1987)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 10 (1987), S. 32-38 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary columns, glass ; Polyalkyleneglycol ether phases ; Inert columns ; Immobilization by condensation ; Methyltrimethoxysilane, coupling agent ; Trifluoroacetic acid, catalyst ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Using UCON 50 HB-5100, one of the most successful stationary phases in capillary gas chromatography during the past decade, as an example, we wish to redirect attention to the excellent properties of the polyethylene/polypropyleneglycol ether copolymer coatings. Based on experience gained in work with OH-terminated polysiloxanes, a method is described for preparing inert and relatively temperature stable chemically bonded and crosslinked coatings in a single working step. Methyltrimethoxysilane was used as coupling agent, and trifluoroacetic acid was introduced as an acidic catalyst. The reaction mechanisms involved as well as the influence of additional crosslinking on the column behavior are discussed, particularly with respect of the inertness of the coatings.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240100107
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  • 42
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    Preparation of inert glass capillary columns coated with industrially produced N,N,N′, N′-tetrakis (polyethylene/propylene glycol ether) ethylenediamines (tetronics) as stationary phases (1987)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 10 (1987), S. 97-99 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary columns glass ; Tetronic, stationary phase ; Inert column ; Irganox 1010 ; Antioxidant ; Catalyst ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240100211
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  • 43
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    Native ethylene glycol in wine: Application of a dead volume free, very fast “deans heart-cut” system on-line with multi-chromatography (1987)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 10 (1987), S. 240-243 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary columns, coupled ; Heart cutting ; Multi-chromatography ; Wine analysis ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Data about the existence of native HO—CH2—CH2—OH (MEG) in natural wines and champagne has led to delicate questions because of legal decisions already made to declare wine or champagne illegal for sale if the MEG concentrations found are above 10 mg/liter. Action has been taken because of the DEG (diethylene glycol) disaster in European wines of 1985…86. An incorrect legal decision was made due to the belief that MEG cannot be produced biochemically by grape vines. A further reason may be lack of correct data on native MEG trace concentrations, as a result of the special behavior of this diol. As first member of a homologous series whose higher members (C4) are normally found in all wines at quite high concentration levels, MEG shows extremely adsorptive behavior. The solution of the chromatographic problems is summarized in this paper. MEG concentrations in Riesling as example are in the range of 2 to 6 mg/liter and can easily be increased by biotechnological steps to a level of around 10 to 60 mg/liter. This is again due to the specific adsorptive behavior of MEG, which can be enriched on filter surfaces and displaced when the wine acidity changes with changing types. In order to control and guarantee the qualitative and quantitative results of MEG analyses we used a combination of Deans heart cutting on-line with Multi-Chromatography. It was easy to produce false data by many otherwise useful single column or two-dimensional separation processes, etc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240100506
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  • 44
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    Electronic Resource
    Adsorption phenomena of 2, 3, 7, 8-tetrachlorodibenzodioxin and OCDF in high resolution gas chromatography (1987)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 10 (1987), S. 41-42 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary columns ; PCDD's ; PCDF's ; Adsorption phenomena ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240100109
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  • 45
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    A study of chromatographic properties of liquid crystalline polyacrylates using WCOT columns in gas chromatography (1987)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 10 (1987), S. 77-81 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary columns ; Liquid crystalline stationary phases ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Liquid crystalline polyacrylates (LCPAs) are evaluated as stationary phases for capillary gas chromatography (CGC). Aromatic hydrocarbons as well as polar isomeric compounds are used as test solutes to compare the polarity of the LCPAs with a conventional polysiloxane column and a Carbowax 20M column. The relative polarity of the columns with respect to change in the lateral and terminal substituents is also discussed. Lateral substitution, polarity of the terminal group, together with the solute size, affect the LCPA selectivity.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240100205
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  • 46
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    Electronic Resource
    High oven temperature  -  cold on-column injection for the automated CGC analysis of high molecular weight compounds such as triglycerides (1987)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 10 (1987), S. 263-268 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Fused silica capillaries ; Automated cold on-column injection ; High oven temperature ; Lipid analysis ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Modification of the Carlo-Erba cold on-column injector for (automated) analysis of high molecular compounds at high oven temperature is described. The secondary cooling tube of the cold on-column injector is replaced by a lengthened tube through which a high air flow is directed. The injection site is maintained at 65-70 °C while the oven is at high temperature (≷ 300 °C). For automated injection, a short deactivated precolumn of 22 to 30 cm × 0.53 mm i.d. is coupled to the analytical column via a butt connector with make-up gas supply. For a triglyceride mixture, automatically injected at 300 °C, the mean % deviation for all peak areas was 1.8% and the mean % deviation for all retention times was 0.09 % for five consecutive runs.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240100510
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  • 47
    Electronic Resource
    Electronic Resource
    Multipurpose cold injector for high resolution gas chromatography (1987)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 10 (1987), S. 288-296 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary columns ; Universal sampling system ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The multipurpose cold injector described in this paper represents a solution for an universal sampling system for high resolution gas chromatography. The system is modular and is built around the Carlo Erba cold on-column injector provided with secondary cooling. An auxiliary module, easily fixable on the bottom of the on-column injector, creates a temperature programmable vaporizing chamber making the system also suitable for cold split-splitless injections or solvent venting prior to the sample transfer into the capillary. The system can be operated manually or in a fully automatic mode using the auto-sampler for cold on-column injections. The experimental data illustrate its benefits and limitations.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240100514
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  • 48
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    Electronic Resource
    Importance of the retention index standards in determining the magnitude of McReynolds phase constants (1987)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 10 (1987), S. 670-671 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Retention index standards ; McReynolds phase constants ; Partial molar Gibbs free energy ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240101211
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  • 49
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    Rayleigh instability of stationary phase films in capillary column chromatography (1987)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 10 (1987), S. 128-136 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary columns ; Coating of capillaries, static and dynamic ; Rayleigh instability ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The film of stationary phase on the wall of a capillary column and that of the phase solution during both static and dynamic coating is subject to Rayleigh instability, which is quite independent of so-called wettability. A theory is developed which shows that the logarithmic growth rate of Rayleigh instabilities is proportional to the surface tension and to the third power of the film thickness, and inversely to the viscosity and to the fourth power of the capillary diameter. Determination of the variation of the viscosities of stationary phase solutions with concentration in coating solvents, and the variation of the viscosities of neat stationary phases with temperature, both revealed that heating and/or diluting changed the viscosities of phases with π-electron-containing, groups much more than for polydimethylsiloxanes. Rayleigh instability is therefore more important during coating of phenyl-containing phases such as OV-17, and later during column operation. The efficiencies of capillary columns of different diameters coated with a number of phases under different conditions of temperature and coating rate, and then operated at different temperatures were in good agreement with the predictions of the theory.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240100305
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  • 50
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    Optimizing gas chromatographic separations (1987)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 10 (1987), S. 231-234 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary columns ; Selectivity tuning ; Optimization ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: While separations based on the use of stationary phases specifically designed to maximize solute alphas can, in the strictest sense, be precisely optimized only under specific isothermal conditions, the approach has previously been used even with temperature programmed separations. Selectivity can by further “tuned” by (1) differential variations in the carrier gas velocity through dissimilarly coated coupled columns, and (2) temperature variations in columns of at least moderate polarity. This paper explores the latter approach.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240100504
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    The allyl bonded stationary phase. II. Conversions to new phases for gas chromatography (1987)
    Springer
    Chromatographia 23 (1987), S. 3-6 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Allyl bonded phases ; Addition Reactions ; Synthesis of new bonded phases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The presence of the double bond on the allyl moiety has been utilized as a site for addition reactions which could produce new stationary phases. Bromination and hydrobromination reactions have been employed to prove the feasibility of making modifications to the allyl bonded phase. Both retention volumes and thermodynamic parameters for the solutes studied change upon conversion to one of the brominated phases. Sample size studies are consistent with a bonded phase adsorption mechanism. FTIR spectra also confirm the modifications which have occurred on the allyl bonded material.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02310409
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  • 52
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    Identification of the components of aldoses in a tautomeric equilibrium mixture as their trimethylsilyl ethers by capillary gas chromatography (1987)
    Springer
    Chromatographia 23 (1987), S. 43-46 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Carbohydrate TMS-ethers ; Tautomeric equilibrium mixtures of aldoses ; MS and NMR identification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Equilibrium tautomers of aldopentoses (arabinose, ribose, xylose and lyxose) and aldohexones (allose, altrose, gulose, idose and talose) have been analyzed as their trimethyl-silyl ethers by capillary GC. Pentoses were separated on SE-54 and hexoses on OV-225. The four components of the tautomer equilibrium mixture have been identified using GC/MS and NMR data.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02310417
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    How to count strong adsorption sites by gas chromatography? (1987)
    Springer
    Chromatographia 23 (1987), S. 722-726 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Adsorbents for gas chromatography ; Strong adsorption sites ; Heterogeneity of silica surface
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A simple gas chromatographic method is presented for the determination of the quantity of the strongest adsorption sites on an adsorbent's surface. The method consists of the blockage of the sites with quasi-irreversibly adsorbed, known amount of a strongly interacting compound and subsequent measuring of the retention of a hydrocarbon during the presence of the blocking compound in the column. Heterogeneity of chromatographic grade silicas is investigated with this method.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02312663
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    Esterification of aliphatic hydroxy acids to n-propyl esters in aqueous solutions for their gas chromatographic analysis (1987)
    Springer
    Chromatographia 23 (1987), S. 760-763 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Esterification in aqueous solution ; n-Propyl esters of aliphatic hydroxy acids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Aliphatic hydroxy acids were esterified in aqueous solution in the presence of different amounts of sulfuric acid. Esterification of lactic, tartronic, malic and citric acids in water/n-propanol mixtures with mole ratios between 0.03 and 2.15 can be utilized for the determination of these acids by gas chromatography. Water does not interfere at water/n-propanol mole ratios below 0.03. For mole ratios above 0.03 anhydrous sodium sulfate is used for the binding of water. The mole ratio range was 0.24–2.13 for anhydrous sodium sulfate/water, and 0.16–1.28 for sulfuric acid/anhydrous sodium sulfate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02312669
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    Determination of the concentration of silanol groups by a chemical reaction with methyllithium and GC measurements of evolved methane (1987)
    Springer
    Chromatographia 23 (1987), S. 767-769 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Gas chromatography ; Bonded silica ; Residual silanol groups
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Silanol groups of chromatographic material surfaces were determined by chemical reaction with methyl-lithium. Evolved methane was measured by a gas chromatographic method using a column packed with molecular sieves. This chromatographic technique leads to very reproducible results, particularly for the control of the hydroxylation of a silica gel and for the analysis of residual groups at the surface of bonded silica.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02312671
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    Chromatographic determination of lactulose (1987)
    Springer
    Chromatographia 23 (1987), S. 132-136 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Column liquid chromatography ; Thin-layer chromatography ; Analysis of lactulose in carbohydrate mixtures
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Lactulose is a disaccharide with important implications in medicine, nutrition and dairy technology. It has to be determined usually as a minor component in complex matrices containing many other sugars. This paper describes the different chromatographic techniques (planar, liquid and gas chromatography) which have been proposed for the separation and quantification of lactulose in mixtures with other carbohydrates; the advantages of each technique are compared and some features where more research is necessary are outlined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02312889
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    A new type of two-dimensional packed + capillary column GC system. I. Theory (1987)
    Springer
    Chromatographia 23 (1987), S. 487-491 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Packed+capillary GC switching system ; Column efficiency utilization ratio ; New packed precolumn
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary To match the need of high efficiency capillary column (plate number N2, Plate height H2 and carrier gas linear velocity U2), a new high efficiency packed column (N1, H1 and U1) at high carrier gas velocity with small capacity factor has been developed in the light of theoretical discussion of factors effecting the column efficiency utilization ratio.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02309416
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    Comparison of some properties of immobilized polyethylene glycol type stationary phases modified with an acid (1987)
    Springer
    Chromatographia 23 (1987), S. 553-556 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Capillary columns ; Immobilized Carbowax-type stationary phases ; Free fatty acids analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Capillary columns coated with acid-modified poly-(ethylene glycol)-type immobilized stationary phases have been studied. The thermostability and chromatographic behaviour of the columns and the stability of the coated films after washing with different solvents were investigated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02324862
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    Measurement of thermodynamic equilibria by chromatography (1987)
    Springer
    Chromatographia 23 (1987), S. 215-219 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Liquid chromatography ; Thermodynamic equilibria ; Solution and adsorption thermodynamics ; Gas adsorption isotherms
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary After a brief recall of the chromatographic principles, the different applications of gas chromatographic measurements of thermodynamic equilibria were reviewed. Gas and liquid chromatographies are now well known and elegant methods for measuring the physicochemical properties and phase equilibrium thermodynamic constants. Although fundamentally a dynamical method and mostly known as a powerful separation technique, chromatography can be schematized by a sucession of equilbria of a chemical species partitioning between a mobile phase and a fixed liquid or solid stationary phase. It can be operated in either infinite dilution or finite concentration conditions and permits to collect a large number of data for calculating molecular interactions for solutes which are either rare or available at the trace level. Gas chromatography permits the measurement of gas adsorption isotherm, gas-liquid equilibria, molecular diffusion and interaction virials. The modelization of successive partition equuilibria occuring in the chromatographic column leads to rather simple expression of differential enthalpy, entropy, free energy of adsorption or solution, variation of heat capacity, complexation constant, second virial coefficients, gas-solid and gasliquid isotherm and also binary or ternary equilibria. The possibilities of High Performance-Liquid Chromatography to investigate adsorption from solutions and chemical equilibria are also discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02311484
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    Least-squares schemes for time integration of thermal problems (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 159-175 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The paper proposes a generalized least-squares time finite element procedure for analysis of transient field problems. It leads to a very general four parameter and two time level family of schemes. The free parameters are optimized in terms of accuracy, stability and oscillatory behaviour of the computational algorithm. In the case of linear problems an unconditionally stable scheme of fourth-order accuracy is obtained. Special choices of the free parameters also give a number of well-known time-integration schemes, such as the Zienkiewicz-Lewis third-order algorithm, the Goodrich scheme and standard schemes such as the Crank-Nicolson and backward fully implicit schemes. The main disadvantage of the higher order algorithm is a large bandwidth of the system matrix owing to the matrix terms of the form KTK. This drawback is reduced for special choices of the parameters by forming a product formula. Somewhat more computation is required than for popular schemes such as the generalized midpoint rule, depending on the prescribed variables. Numerical comparisons are made between the proposed higher order schemes and standard schemes.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620240112
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    The front-tracking scheme for the one-dimensional freezing problem (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 859-869 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The one-dimensional freezing problem can be solved numerically for the temperature distribution accompanied by explicit reference to the position of the freezing front at each time interval. A new front-tracking scheme provides accurate determination of the phase front, which is an essential requirement for the temperature distribution in the different phases of such problems. The front is made to coincide with a grid-node throughout the analysis. The scheme uses a combination of the finite difference and the finite element methods for obtaining the solution of the freezing problems.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620240503
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    Model-size reduction for the analysis of symmetric structures with asymmetric boundary conditions (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 913-926 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A simple computational procedure is presented for reducing the size of the analysis model for a symmetric structure with asymmetric boundary conditions to that of the corresponding structure with symmetric boundary conditions. The procedure is based on approximating the asymmetric response of the structure by a linear combination of symmetric and antisymmetric global approximation vectors (or modes). The key elements of the procedure are (a) restructuring the governing finite element equations to delineate the contributions to the symmetric and antisymmetric components of the asymmetric response, (b) successive application of the finite element method and the classical Rayleigh-Ritz technique. The finite element method is first used to generate a few global approximation vectors (or modes). Then the amplitudes of these modes are computed by using the Rayleigh-Ritz technique.A tracing parameter is introduced which identifies all the contributions to the antisymmetric response. The global approximation vectors are selected to be the solution corresponding to a zero value of the tracing parameter and the various-order derivatives of the solution with respect to this parameter, evaluated at zero value of the parameter. The size of the analysis model used in generating the global approximation vectors is identical to that of the corresponding structure with symmetric boundary conditions.The effectiveness of the computational procedure is demonstrated by means of numerical examples of linear static problems of shells, and its potential for solving non-linear problems is discussed.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620240506
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    A self-adaptive co-ordinate transformation for efficient numerical evaluation of general boundary element integrals (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 959-973 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Almost all general purpose boundary element computer packages include a curved geometry modelling capability. Thus, numerical quadrature schemes play an important role in the efficiency of programming the technique. The present work discusses this problem in detail and introduces efficient means of computing singular or nearly singular integrals currently found in two-dimensional, axisymmetric and three-dimensional applications. Emphasis is given to a new third degree polynomial transformation which was found greatly to improve the accuracy of Gaussian quadrature scheme's within the near-singularity range. The procedure can easily be implemented into existing BE codes and presents the important feature of being self-adaptive, i.e. it produces a variable lumping of the Gauss stations toward the singularity, depending on the minimum distance from the source point to the element. The self-adaptiveness of the scheme also makes it inactive when not useful (large source distances) which makes it very safe for general usage.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620240509
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    Some improvements of the finite element solution for one-dimensional problems (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 993-1014 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: New algorithms which improve the finite element solution on a fixed mesh of the domain are developed. For this, objective functions which depend on a positive parameter to be determined are proposed. These functions lead to criteria which combine in several ways the residual of the solution, the approximation in the Euclidean norm of the value of the solution at the nodes, and the approximations in the energy and Hk norms. Some aspects of optimality are studied and, finally, numerical results are given.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620240511
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    The ‘effective-stress-function’ algorithm for thermo-elasto-plasticity and creep (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 1509-1532 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: An algorithm for stable and accurate computations of stresses in finite element thermo-elastic-plastic and creep analysis of metals is presented. The effective-stress-function algorithm solves the governing equations of the inelastic constitutive behaviour by calculating the zero of the appropriate effective-stress-function: a functional relationship which involves as unknown only the effective stress. The derivation of the effective-stress-function for thermo-elasto-plasticity conditions, including creep, for 2-D and 3-D analysis is presented, and the algorithmic steps of the stress solution are discussed. For use in the stiffness matrix a tangent material stress-strain relationship is evaluated consistent with the effective-stress-function algorithm. The solution of some demonstrative problems shows the effectiveness of the solution procedure.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620240808
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    Making the boundary element method less sensitive to changes or errors in the input data (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 1533-1540 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: To solve a problem by the boundary element method requires a solution of an integral equation. By discretizing the boundary, the integral equation is reduced to a set of linear algebraic equations. If the matrix in algebraic equation is not diagonal dominant or more precisely, poorly conditioned, then the accuracy of the numerical solution becomes very sensitive to small changes in the input data. Small errors in the input data or changes in the mesh description can change the solution drastically.In this paper a scheme is described which improves the condition of the matrix. Furthermore, it also reduces the sensitivity of the condition of the matrix to changes in the mesh description. The ideas described are applicable to any boundary element formulation. However, the numerical examples are from two-dimensional elastostatics solved by the indirect version of the boundary element method.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620240809
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    A numerical method for dynamic analysis of a general cross-section rod under combined loads (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 1079-1091 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: This paper is concerned with a method for obtaining stresses in a rod of arbitrary cross-section subjected to combined loads of bending, shearing and torsion which are the complicated functions of time. In the first step, the analysis derives the bending moment, shearing force and torsional moment by use of a combination method of the Laplace transformation and Fourier series expansion. The transient stresses are obtained based on the two-dimensional theory of elasticity, but in which the Fourier expansion collocation procedure is applied to deal with the complex boundary shape of the cross-section. To affirm the validity of this analysis, experimental tests are also carried out for an oval rod subjected to the three combined transient loads.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620240604
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    Norm methods and partial weighting in multicriterion optimization of structures (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 1101-1121 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Methods for generating Pareto optimal solutions to a multicriterion optimization problem are considered. The norm methods based on the scalarization of the original multicriterion problem by using the lp-norm are discussed in a unified form and a parametrization suitable for different interactive design systems is suggested. In addition, an alternative approach which, instead of scalarization, reduces the dimension of the multicriterion problem is proposed. This is called the partial weighting method and it can beinterpreted as a generalization of the traditional scalarization technique where the weighted sum of the criteria is used as the objective function. The first of these two approaches (norm method) is very flexible from a designer's point of view and it can be applied also in non-convex cases to the determination of the Pareto optimal set whereas the latter (partial weighting method) is especially suitable for problems where the number of criteria is large. Throughout the article several illustrative truss examples are presented to augment the scanty collection of multicriterion problems treated in the literature of optimum structural design.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620240606
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    An efficient quadrilateral element for plate bending analysis (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 1123-1155 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A simple, shear flexible, quadrilateral plate element is developed based on the Hellinger/Reissner mixed variational principle with independently assumed displacement and stress fields. The crucial point of the selection of appropriate stress parameters is emphasized in the formulation. For this purpose, a set of guidelines is formulated based on the following considerations: (i) suppression of all kinematic deformation modes, (ii) the element has a favourable value for the constraint index in the thin plate limit, (iii) element properties are frame-invariant. For computer implementation the components of the element stiffness matrix are evaluated analytically using the symbolic manipulation package MACSYMA. The effectiveness and practical usefulness of the proposed element are demonstrated by the numerical results of a variety of problems involving thin and moderately thick plates under different loading and support conditions.
    Additional Material: 19 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620240607
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    The effect of compatibility conditions on optimal design of flexural structures (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 1173-1185 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: In most structural optimization problems the time-consuming implicit analysis must be repeated many times during the solution process. To alleviate this difficulty, the implicit analysis equations are often neglected or replaced by explicit approximations.Assuming the force method analysis formulation, optimal solutions of two problems are studied and compared:(a)The equilibrium linear programme (ELP), where only explicit equilibrium conditions are considered in the analysis model(b)The non-linear programme (NLP), where the implicit compatibility conditions are included to obtain a complete formulation.The effect of geometrical parameters on optimal solutions of both problems is investigated and geometries with particular properties are identified. The main observations that have been made are as follows:(a)Multiple optima of the ELP have been obtained for geometries where transitions in the set of active constraints at the ELP optimum occur. The NLP optimum for such a geometry might be included in the set of ELP optima.(b)Identical optimal solutions of the two problems have been found for geometries where transitions in the set of active constraints at the NLP optimum occur.The explicit ELP can be solved instead of the implicit NLP for the two classes of transition geometries.The relationships between optimal force distributions and objective function values for the two problems are studied and examples where compatibility conditions can be neglected are illustrated.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620240609
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    Lanczos method for heat conduction analysis (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 251-262 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: An analysis technique that uses the Lanczos vectors to construct a Reyleigh-Ritz solution for the transient heat conduction problem is presented. The Lanczos vectors are derived from the heat supply vector and incorporate all the information peculiar to a given problem. They are orthonormal with respect to the heat capacitance matrix and are generated with a minimum of computational effort. Furthermore, an error bound is derived that can be used to terminate the Lanczos algorithm as soon as the number of vectors required to obtain a desired degree of accuracy has been generated. A summary of the algorithm is presented and the accuracy and efficiency of the method is illustrated using a numerical example.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620240117
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    An enthalpy method for convection/diffusion phase change (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 271-284 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: An enthalpy formulation for convection/diffusion phase change is developed. The essential feature of this formulation is that latent heat effects are isolated in a source term. This formulation is applicable to a general convection/diffusion phase change, i.e. it is valid in the cases of evolution of latent heat either at an isothermal temperature or over a temperature range. Before implementation of the enthalpy formulation, a technique is required to ensure that velocities predicted to be in a solid region actually take the value zero. Three alternative schemes for achieving this are presented.The enthalpy formulation and velocity correction schemes are independent of the numerical technique. As an example of how the method can be implemented a control volume numerical discretization is chosen. This implementation is applied to two test problems: a solidification phase change in a cavity under conduction and the same phase change under conduction and natural convection. The natural convection problem is used to compare the performances of the various velocity correction schemes. The results of the problems are in good agreement with available analytical solutions and previous numerical solutions.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620240119
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    An adaptive procedure for eigenvalue problems using the hierarchical finite element method (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 319-335 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: An adaptive procedure for the solution of the generalized linear eigenvalue problem within the hierarchical finite element method is described. The problem of finding for a given discretization, an upper limit eigenvalue that is accurate within a prescribed tolerance is especially studied. An error estimator is presented and a recomputational scheme for improved solutions is proposed. A numerical example is included.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620240205
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    Making curved interfaces straight in phase-change problems (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 375-392 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: This paper presents a method for straightening curved interfaces arising in phase-change problems. The method works on isoparametric finite elements, performing a second transformation which maps the master element onto a new one in which the interface looks like a straight line. This allows using the current Gaussian integration technique for squares to evaluate the integrals over each phase. The method provides a better estimation of the contribution of latent heat effects to the residual vector, compared to those obtained by using the assumption that the interface is straight. Appropriate guidelines for solving the non-linear system of equations arising in this kind of problem are also given. Several numerical examples are presented to show the performance of the method.
    Additional Material: 18 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620240208
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    Finite element solution of three-dimensional incompressible fluid flow problems by a preconditioned conjugate residual method (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 447-457 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A new algorithm for the solution of the three-dimensional Navier-Stokes equation using the mixed formulation and an incomplete factorization technique is presented. The linear system obtained at each modified Newton-Raphson iteration is solved by the preconditioned conjugate residual method (PCR) using an out-of-core incomplete LU factorization as preconditioning. This factorization is performed on a matrix stored by a new static storage method called the packed skyline method. The performance of the proposed algorithm is assessed for the wall-driven cubic cavity problem using the Q1+ -P1 enriched element.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/nme.1620240211
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    Announcements (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 474-476 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620240214
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    Mapped infinite elements in soil consolidation (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 513-527 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The problems of consolidation often involve unbounded continua. The most common solution is then achieved by limiting the studied area through the introduction, at finite distance, of a boundary on which adequate conditions on the field variables are imposed. In this paper mapped infinite elements are used to model the far-field solution. Spatial discretization is hence performed on the basis of both finite and infinite elements. In two examples, solutions involving finite and infinite elements are compared with known analytical solutions and it is shown that an excellent agreement can be achieved by the use of mapped infinite elements.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620240304
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  • 78
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    An improved computational technique for perturbations of the generalized symmetric linear algebraic eigenvalue problem (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 529-541 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A technique is developed and presented which improves the accuracy of the predictions for the eigenvalues of the usual first order perturbation scheme for the generalized symmetric linear algebraic eigenvalue problem. The improved method very simply replaces the usual B-norms appearing in the denominator of the expressions for the first order changes in the eigenvalues by BP-norms where BP is the perturbed B matrix. With increasing sizes for the perturbations the improved technique produces results whose accuracy approaches those of the usual second order predictions. Numerical studies are presented to support the analysis.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620240305
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  • 79
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    Adaptive refinement for least-squares finite elements with element-by-element conjugate gradient solution (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 569-580 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: An error analysis and an adaptive refinement scheme are developed for use with a class of least-squares finite element methods. The error indicators for the refinement procedure are based on element residuals which are calculated as part of the least-squares method. The solution scheme used in the supporting numerical studies employs an elment-by-element conjugate gradient algorithm. Consequently, storage and computation are not influenced by nodal numbering.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620240308
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  • 80
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    Conference diary (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 2237-2238 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620241114
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  • 81
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    Announcement (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 2239-2239 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620241115
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  • 82
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    Boundary elements for three-dimensional elastic crack analysis (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 2253-2271 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: In this paper 8-node traction singular boundary elements are employed to represent displacement and traction variations in the vicinity of the crack front in three-dimensional geometries. The numerical procedure suggested for evaluating the singular integrals extending over these special elements is described. The efficiency and accuracy of the special elements and integration procedure are demonstrated by the results obtained in a simple test problem whose analytical solution is known. The interaction of two circular coplanar cracks embedded in an infinite medium under uniform tension loading is also analysed. Finally, the stress intensity factor variation computed for a semi-circular inner surface crack in a pressurized cylinder is presented.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620241203
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  • 83
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    Dynamics of the bilinear Mindlin plate element (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 2343-2356 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Plate and shell finite elements based upon Mindlin plate theory and evaluated by one-point quadrature are attractive because of their effectiveness for both thick and thin shells, at minimal computing cost. However, these elements are rank-deficient and must be stabilized to obtain reliable behaviour. Methods for achieving full rank of the stiffness and for stabilizing element behaviour in static analysis and in explicit dynamic calculations exist and are quite effective. This paper addresses the remaining issue of controlling spurious modes of response in vibration analysis and implicit dynamic solutions. Several alternatives for the element mass formulation are examined in detail. We show that non-physical dynamic modes present a potential problem with most mass matrix formulations, and that spurious modes other than the familiar hourglassing motion are possible. A combination of projection methods and reduced quadrature is suggested which eliminates these deficiencies and produces accurate numerical results. The remaining techniques investigated give rise to anomalous behaviour which make them unsuitable for general use.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620241208
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  • 84
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    An assumed covariant strain based 9-node shell element (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 2389-2411 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A new shell element, which is free from serious locking problems and which does not possess hourglass modes, is proposed. Solutions obtained with this element exhibit good convergence and are satisfactorily insensitive to mesh distortion. The element also exhibits good convergence for plates with variable thickness. This element is based on the use of assumed covariant strains which are obtained from the covariant strain field defined with respect to the element natural co-ordinate system. Only the linear version for thin shell cases is considered. The element performance is tested by application to several standard plate and shell problems. A problem involving variable thickness is also presented.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620241211
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  • 85
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    Practical stability analysis of finite difference equations by the matrix method (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 679-687 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: It is shown how the various norms of the coefficient matrix of a set of finite difference equations can, in many cases, be employed in an easy, straightforward fashion to find sufficient conditions for stability in situations involving non-periodic boundary conditions and variable coefficients. With the aid of the easily computed norms, particularly the infinite norm, one does not have to rely on the necessary condition provided by the spectral radius, which has been the main basis of criticism of the matrix method in the past.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620240403
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  • 86
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    Stress oscillations in plane stress modelling of flexure - a field-consistency interpretation (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 711-724 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Exactly integrated isoparametric plane stress elements behave poorly in flexure. The 4-noded element ‘locks’, with errors that progress indefinitely as element aspect ratio increases. Reduced integration of the shear strain energy eliminates this locking entirely. The 8-noded element does not lock, but improves in performance with reduced integration of shear strain energy. Both elements, with their original shape functions, show severe shear stress oscillations in flexure. In this paper we attribute these oscillations to the lack of ‘consistency’ of shear strain fields derived directly from independent field-variable interpolations. We derive error models for specific tractable examples which can confirm the accuracy of this conceptual scheme through digital computation using the finite element models. A field-consistent redistribution strategy for the shear strain field is offered as an elegant procedure to free the elements of spurious oscillations and give a ‘lock’-free performance.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620240405
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  • 87
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    A finite element model for column-supported shells of revolution (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 1951-1971 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A finite element model suitable for the analysis of column-supported shells of revolution is presented. This model combines in a single analysis axisymmetric shell elements with nodal circles and column elements with nodal points. Thus, it takes advantage of the axisymmetry of the shell, while the non-axisymmetric nature of individual columns is fully accounted for. The compatibility between the two different types of elements is achieved through the use of a co-ordinate transformation. The accuracy of the solutions is demonstrated through numerical examples. When a shell of revolution supported on equispaced columns of the same stiffness is subjected to a harmonically varying load in the circumferential angle, it is found that the resulting displacements are associated with selective harmonic terms. An equation which precisely defines this coupling mechanism is also derived.
    Additional Material: 23 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620241010
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    Applied stress analysis, C.T.F. Ross, Ellis Horwood (Chichester), 1986. No. of pages: 322. Price £16.95/$30.75. ISBN: 74580 155 2 (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 2035-2035 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620241014
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  • 89
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    Isotropic plate elements with shear and normal strain deformations (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 1671-1695 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Plate-bending finite elements are developed for thin and moderately thick plates. The element takes into account the influence of the transverse normal strain and the transverse shear effects. For the computation of the stresses, an additional plate element is developed to determine the inplane displacements and forces. The combined effects of the plate-bending and inplane elements are used for the complete solution of the problem. Several examples are solved and compared with their corresponding exact solutions.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620240906
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  • 90
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    Elastic strain effects during steady-state rolling of visco-elastic slabs (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 1659-1669 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The effect of elastic strains in the steady-state visco-elastic fluid flow under the rolling process is analysed quantitatively. Spurious oscillations in the stress deviator and pressure fields are precluded and the rate of convergence is improved when the Petrov-Galerkin method, which is based on a least-square method, is introduced into the finite element equation for the constitutive law.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620240905
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    Direct computation of Cauchy principal value integrals in advanced boundary elements (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 1711-1720 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: This paper presents a new method for the direct computation of strongly singular integrals existing in the Cauchy principal value sense. It can be usefully applied in the solution by the direct boundary element method of many different problems. Initially, some considerations are provided in order to summarize the state-of-the-art on this issue. Then the features of the proposed method are reported. The procedure allows the direct calculation of Cauchy principal value integrals with first-order singularity and it is applicable even in advanced boundary element methods employing high-order elements. It requires only the use of standard Gaussian quadrature formulae plus the computation of a logarithmic term. Some examples show the effectiveness and efficiency of the procedure.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620240908
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    Plotting of contours in a natural way (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 1757-1769 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A simple and straightforward scheme for plotting contours is introduced. For any function the appropriate contours are traced on the paths of constant function values disclosing the information contained in the shape functions. The exactness of the contours matches that of the finite element analysis. Extreme value considerations must be carried out to decide whether contours appear in an element at all. Three co-ordinate systems are dealt with: the local, the global and the screen co-ordinate system, and the necessary mutual transformations. A short section deals with the treatment of contour discontinuities across element borders which frequently occur with stresses and heat fluxes. Finally, some examples are shown.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620240911
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  • 93
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    A new partially bonded beam element for analysis of shear walls (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 2217-2236 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A finite element formulation for multi-panel shear walls based on a partially bonded beam system has been proposed. Idealization of a shear wall by a partially bonded multi-layered beam element reduces the storage and computer time considerably. The finite element model has been employed extensively for parametric study of prefabricated shear walls of different widths and heights. Different numbers of in-situ joints in the prefabricated shear wall assembly with varying shear stiffness of joints have also been considered. The parametric study gave an insight to the structural response of the wall system. Based on the non-linear shear stiffness characteristic of in-situ joints determined experimentally, the nonliner behaviour of a prefabricated shear wall has been determined and the failure load has been predicted.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620241113
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    Composite mappings for planar mesh generation (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 2241-2252 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A new algorithm is presented for automatically grading meshes generated over planar triangular and quadrilateral regions using parametric mappings. Rational parametric bicubic Bézier polynomials are coupled with an element density function to concentrate elements around regions of high solution gradients.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620241202
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    FEM-analysis of transverse vibrations of an axially moving membrane immersed in ideal fluid (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 2301-2313 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Transverse vibrations of an axially moving (travelling in its own plane) membrane submerged in ideal fluid are analysed using the FEM. The discrete equations differ from the equations of the common coupled problem in that there appear two additional inertia terms due to the convective acceleration. The effect of the density of the element mesh, the effect of the truncation distance and the effect of various lumping techniques on the accuracy of the results are studied. The FEM-results are compared with available analytical and experimental results. The agreement seems to be rather good.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620241205
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    Adaptive mesh redistribution for a boundary element (panel) method (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 2315-2325 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: In this paper, we extend the concept of a grading function, as introduced by Carey and Dinh2 in a one-dimensional context, to curved contours. We then apply the idea to adaptive grid redistribution for a boundary element method to solve a model boundary value problem. Numerical results are included for a potential problem to demonstrate the effect of the redistribution scheme on the solution and the geometry of the domain.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620241206
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  • 97
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    Second order sensitivity analysis of lumped mechanical systems in the frequency domain (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 2357-2366 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: This paper presents a method for determining the second order sensitivity matrix and logarithmic sensitivity functions in the frequency domain. The procedure described is applicable to any discrete and viscously damped mechanical system.A definition of the second order logarithmic sensitivity function has been proposed. The examples shown indicate that logarithmic sensitivity functions of the second order preserve the qualitative character of first order sensitivity functions and are more sensitive to changes of system parameters. The influence of large parameter changes on second order sensitivity functions has also been investigated.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620241209
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  • 98
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    Computational method for integral equations, L. M. Delves and J. L. Mohamed, Cambridge University Press, 1985. Price: £35.00. ISBN 0 521 26629 7 (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 2036-2036 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620241015
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  • 99
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    Discrete Green functions for layered strata (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 1645-1658 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A finite-element discretization of a layered stratum is considered. The response to a time-harmonic load at a single node is calculated. For all practical purposes, the result is obtained in closed form in the case of two dimensions (line load) while the Fast Fourier Transform is employed in the three-dimensional problem (point load).
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620240904
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  • 100
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    Notes on the stability of non-rectangular space-time finite elements (1987)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 24 (1987), S. 1721-1739 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The method of space-time finite elements enables the simple solution of quite new problems. It is possible to assume the arbitrary partition of the structure area in each moment of integration of the motion equation. Instability is caused by a too large time step and too great changes of joint locations in successive time steps. A changeable spatial partition is useful in contact dynamic problems, in the case of a travelling support, generally in problems with movable edges. In this paper a stability problem is described and some investigations for chosen types of non-rectangular space-time finite elements are carried out. Linear and surface elements which in time space gain an additional time dimension are presented. Some numerical examples prove the efficiency of the described method under determined limitations.
    Additional Material: 19 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620240909
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