Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1990-1994  (6)
  • 1955-1959  (4)
  • Chemistry  (9)
  • 25.70.−z  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 344 (1992), S. 223-224 
    ISSN: 1434-601X
    Keywords: numbers ; 25.70.−z ; 27.60.+j
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The 117Inucleus has been investigated in a high-spin γ-spectroscopic study using the NORDBALL detector array. The observed level structures are interpreted as resulting from coexisting collective prolate and oblate as well as non-collective oblate shapes.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 1 (1955), S. 410-412 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 1 (1955), S. 111-117 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Analytical expressions are obtained for the calculation of the time required for batch rectification of binary feeds which may be treated by assuming constant relative volatility and no column holdup. The equations cover constant reflux operations and varying reflux constant product operations for the two cases involving either a large or a small number of theoretical stages. The latter type of calculation has hitherto been possible only by tedious graphical methods. This paper introduces novel pseudoequilibrium curves which lead to simple equations of considerable accuracy. The equations obtained may be rearranged or modified so that other factors such as sharpness of fractionation may be represented analytically.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 2 (1956), S. 412-419 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A study of rates of dissolution of organic solid from a flat surface into turbulent liquid in a mixing tank of 6 in. I.D. is reported for five systems - benzoic acid-n-water, salicylic acid-water, salicylic acid-benzene, succinic acid-n-butanol, and succinic acid-acetone. Previous theories for the rates of mass transfer are reviewed and compared, and experimental results analyzed and correlated by an equation in terms of dimensionless groups similar to that of Hixson and Baum, Sherwood and Gilliland, and Rushton and Oldshue. The close agreement between the theoretical and experimental values of the exponent of the Schmidt number in this equation may provide new and significant evidence for the applicability of the surface-renewal theory to mass transfer from a flat solid surface into a turbulent liquid.For free rotational agitation, a local mass transfer coefficient with respect to the position of a cast solid was detected quantitatively. However, the insertion of four baffles into the tank gave a uniform mass transfer coefficient regardless of the position of the cast solid. A decrease in the mass transfer coefficient was observed when baffles were used.The advantages of the constant and stationary interface, the stability and simplicity of the apparatus, the possibility of duplicating experimental results, and the success of the detection of a local mass transfer coefficient suggest that the present apparatus and procedures could be used for the study of the theory of mass transfer rates from flat surfaces.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 101-110 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This paper describes further research on a 4-in. I.D. by 8-ft. spray tower of Elgin design. Previous work concerned limiting flow and holdup in this tower. Owing to its high capacity and low cost, the spray tower would have much greater commercial application in liquid-liquid extraction if its conditions of transient operation could be predicted and if it could be operated to yield low Ht values. This research attempts to show that transient conditions can be predicted and that low Ht values for both mass and heat transfer can be realized near the limiting flow conditions.Theroretical equations for rate of approach to steady state derived and tested for the systems ethylene dichloride-water-propionic acid and ethylene dichloride-water-acetic acid show that the approach depends on the ratio of the phase flow rates. This study is important for the prediction of start-up time for industrial towers.With the same systems the extraction capacity of the spray tower was investigated up to the condition of rejection. The results were correlated as KEa and Ht, OE vs. a function of the ratio of the phase flow rates. The dispersed-phase flow rate was found to have primary significance.The heat transfer rates between water as continuous phase and solvents of various denisties were correlated as Ht′ values plotted against a function of the ratio of the phase flow rates. The advantages of operation near rejection were demonstrated, and the effect of direction of heat transfer was found to be significant.
    Additional Material: 19 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 42 (1991), S. 2703-2711 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Changes brought about in the crystal morphology of drawn (oriented) PET fibers following both heat and liquid treatments were studied using wide angle X-rays and critical dissolution time techniques. The results obtained showed that the two techniques were sensitive to different but closely related morphological properties of the polymer, the former being sensitive to the apparent degree of the crystalline content, and the latter, a measure of the size of such crystallites that were produced.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 0377-0486
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The dissociation constants for an acetonitrile-zinc complex, (CH3CN)Zn2+, were measured in aqueous solutions containing zinc salts (40-80%, w/w) and acetonitrile by Raman spectroscopy. Quantitative measurements of the intensity of the free and complexed ν(CN) Raman bands at 2264 and 2320 cm-1, respectively, were used to determine the average enthalpy and entropy of the complex dissociation to free acetonitrile in the temperature range 293-343 K for a 70% (w/w) solution of zinc chloride (0.052 mol) in an aqueous solution containing acetonitrile (0.024 mol); δH° and δS° values of 8.4 ± 0.5 kJ mol-1, respectively, were determined.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Journal of Raman Spectroscopy 24 (1993), S. 475-483 
    ISSN: 0377-0486
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The application of Raman spectroscopy to polymers and polymerization processes is surveyed and the advent of recent advances in instrumental techniques to polymer analysis is highlighted. Some of the problems of the more widely-used infrared spectroscopic methods, for example in microstructural analysis of polydienes and copolymers, are discussed and the advantages of the Raman spectroscopic technique are explained. The use of near-infrared excitation and Fourier-transform Raman instrumentation for process monitoring and polymer composite studies is discussed. Raman microscopic and waveguide spectroscopic studies of small samples and polymer coatings on substrates are considered. Other applications are mentioned in the areas of polymer orientation, surface-enhanced Raman scattering, conducting polymers, biopolymers and time-resolved studies.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Journal of Raman Spectroscopy 24 (1993), S. 495-500 
    ISSN: 0377-0486
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The preparation and vibrational spectroscopic characterization of the hitherto unreported products of the copolymerization of 2,3-dimethylbutadiene and methyl methacrylate are presented. The polymers were prepared by free radical polymerization using α,α′-azobisisobutyronitrile as the initiator. Raman and Fourier transform infrared spectroscopic information on the 2,3-dimethylbutadiene-methyl methacrylate copolymer is presented for a range of copolymers differing in the 2,3-dimethylbutadiene to methyl methacrylate ratio. Quantitative information of the microstructure of the polymer and copolymer using the C=C stretching vibrations is provided by Raman spectroscopy. Evidence is presented for the splitting of the C=O stretching vibration, ascribed to aggregated syndiotactic and unaggregated syndio- and isotactic poly(methyl methacrylate) at 1734 and 1724 cm-1, respectively.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Journal of Raman Spectroscopy 24 (1993), S. 435-441 
    ISSN: 0377-0486
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: An attempt was made to use a Fourier transform (FT) Raman spectrometer as a detector with a gel permeation chromatograph which was otherwise configured in the usual way for the measurement of molar mass distribution in polymers. A low-volume flow cell was constructed and the detector response tested both off-line and, in a preliminary way, in-line with the chromatograph. The particular objective was to establish whether it would be possible to measure the microstructural variation in polybutadiene with polymer molecular weight during the chromatographic process. The detector sensitivity was assessed for a range of polybutadienes with different cis-1,4-, trans-1,4- and vinyl-1,2- contents using tetrahydrofuran as solvent and eluent. Data obtained using visible Raman (488.0 nm) excitation and near-infrared (1064 nm) excitation were compared. Although it has been established that the Raman spectrometer is one of the best instruments for the evaluation of the microstructure of polybutadiene when used in a conventional way, it lacks the necessary sensitivity to provide quantitative information on polydienes which elute from a chromatograph. However, there is no reason in principle why an FT-Raman spectrometer should not be used as a concentration detector and for the simultaneous more detailed analysis of polymer composition or micro-structure during the chromatographic process, provided that the scattering intensity of the solute is high relative to the eluent. The potential advantages and the observed problems of what appears to be a novel experiment with an FT-Raman instrument are discussed.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...