Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    3. Einführung (1982)
    Springer
    Langenbeck's archives of surgery 358 (1982), S. 53-55 
    Details
    ISSN: 1435-2451
    Keywords: Gastric cancer ; Evaluation ; Technique ; Magenkrebs ; Bilanz nach 100 Jahren ; Taktik ; Technik
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Theodor Billroth konzipierte vor 100 Jahren die Technik der Magencarcinom-Resektion und zeitlos gültig die taktischen Prinzipien der radikalen kurativen Krebsoperation am Magen.
    Notes: Summary A hundred years ago Theodor Billroth devised the technique of gastric cancer resection and the perpetually valid tactical principles of radical curative gastric cancer surgery.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01271755
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Einfluß des Vitamin A auf die MNNG-induziert Cancerogenese im Drüsenmagen der Ratte (1983)
    Springer
    Langenbeck's archives of surgery 359 (1983), S. 65-73 
    Details
    ISSN: 1435-2451
    Keywords: Vitamin-A ; Gastric cancer ; Chemical carcinogenesis ; Tumor promotion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung In einer Untersuchung an 82 Wistar-Ratten wurden Carcinome des Drüsenmagens mit MNNG erzeugt. Ein Teil der Tiere erhielt zusätzlich hohe Dosen Vitamin A. Wir sahen eine statistisch signifikante Zunahme der Invasionstiefe und damit der Progression des Tumorstadiums unter Vitamin A-Einfluß. Die Häufigkeit des Auftretens von Tumoren war hingegen nicht signifikant verändert. Als Ursache des tumorfördernden Einflußes von Vitamin A in unserem Experiment ist vor allem sein labilisierender Effekt auf celluläre Membransysteme zu diskutieren: 1. Durch Zerstörung lysosomaler Membranen werden Enzyme, Cancerogene und Viren freigesetzt, die direkt oder indirekt zu einer Alteration der DNA führen. 2. Durch Schädigung der Zellmembranen geht die Kontaktinhibition verloren.
    Notes: Summary Carcinomas of the glandular stomach were induced in 82 Wistar rats by means of MNNG1. Part of the group also received high doses of Vitamin A. A consistently significant increase in depth of invasion, i. e. progression of the pathological tumor stage, was observed under the influence of Vitamin A. The frequency of tumor occurrence was not significantly altered. The labilizing effect of Vitamin A on cellular membrane systems is the probable mechanism of Vitamin A's tumor-promoting influence in our experiment: 1. By way of destruction of lysosomal membranes, enzymes, cancerogens, and viruses would be released, leading directly or indirectly to an alteration of the DNA. 2. Damage of cell membranes would lead to loss of the contact inhibition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01254150
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Processing sequence and the properties of vinyl compounds (1988)
    Brookfield, Conn. : Wiley-Blackwell
    Polymer Composites 9 (1988), S. 426-433 
    Details
    ISSN: 0272-8397
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Acid-base interaction parameters were measured by inverse gas chromatography over broad temperature ranges for Poly(vinyl chloride), plasticizer, and CaCO3 fillers. Mixing was performed by three routes. In one, all components were added simultaneously, while in others two of the components were premixed, the third ingredient being added subsequently. Mixing was carried on to equilibrium torque readings. The energy requirement for mixing was found to depend on the interaction balance among the components, and to vary with the procedure selected. Minimum requirement was associated with the simultaneous introduction of all ingredients. Higher energies were needed in sequential mixing schemes, presumably because equilibrium partitioning of components was hindered in these instances. Initial mechanical properties of the compounds did not vary greatly with preparation procedure, but upon aging, mechanical property variations became quite evident. Component repartitioning, driven by shifting interaction balances at aging and at test (room) temperatures are cited as responsible. The kinetics of attaining equilibrium mechanical properties also were found to vary with mixing procedure and to respond to the interaction balance concept.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pc.750090609
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Interfacial interactions and properties of filled polymers. II: Dispersion of filler particlesPaper presented, in part, at the International Polymer Processing Conference, Orlando, FL. May, 1988. (1989)
    Brookfield, Conn. : Wiley-Blackwell
    Polymer Composites 10 (1989), S. 215-221 
    Details
    ISSN: 0272-8397
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The specific interaction characteristics and the inherent agglomeration of variously surface coated rutile pigments have been assessed, respectively, by inverse gas chromatographic and powder rheological methods. Standardized methods were used to disperse the pigments in polyethylene and chlorinated polyethylene. Measurements were made of energy requirements for dispersion and of the quality of dispersion attained. It was found that in the non-polar polyethylene matrix, dispersion processes depended on the strength of pigment agglomerates, but not on the specific interaction potential of the solids. Conversely, in the acidic chlorinated polyethylene, acid/base interactions influenced dispersion but the process was independent of inherent pigment agglomeration.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pc.750100403
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Component interactions and properties of crosslinked vinyl systems (1991)
    Brookfield, Conn. : Wiley-Blackwell
    Journal of Vinyl and Additive Technology 13 (1991), S. 67-72 
    Details
    ISSN: 0193-7197
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Compositions based on PVC, containing DIDP or TOTM plasticizers, and in several cases also containing chlorinated polyethylene (CPE) as property modifier, have been crosslinked by irradiation, using di- and tri-functional acrylic crosslinking agents. Crosslinking effectiveness has been analyzed by solvent swelling data, and the effects of irradiation up to dosages of about 10 Mrad on the mechanical properties of the systems have been recorded. The interaction potential of components used in these systems has been determined by recently-developed methods of inverse gas chromatography (IGC). These classify PVC and CPE as electron acceptors, and the plasticizers as donors. Expectedly, increased moduli and decreased elongational properties follow exposure to gamma-rays. The plasticizers reduce the effectiveness of crosslinking, the magnitude of the reduction being related to the degree of acid/base interaction between PVC and plasticizing fluids. When present, CPE competes with PVC for plasticizer so that for given quantities of DIDP or TOTM, the fraction available to solubilize the host polymer is reduced. In compounds with CPE, therefore, the crosslinking effectiveness of irradiation is raised, consistent with the acid/base balance of interactions, as given by the IGC results. Twin yield points have been observed in the stress-strain curves of compounds containing CPE. It is postulated that distinct, interpenetrating crosslink networks are formed when these polymers are subjected to gamma irradiation.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/vnl.730130111
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Controlled interactions in cellulose-polymer composites. 1: Effect on mechanical properties (1993)
    Brookfield, Conn. : Wiley-Blackwell
    Polymer Composites 14 (1993), S. 449-457 
    Details
    ISSN: 0272-8397
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The surface properties of cellulose fibers have been modified by heat treatment, by silane coupling agents, and by maleated polypropylene grafts. The effectiveness of these methods has been evaluated by electron spectroscopy (ESCA), by contact angle measurements, and by inverse gas chromatography. The latter analyses yielded information on the fibers' acid/base interaction potential. Cellulose was found to be amphoteric, with prevalent acidic properties. Heat and chloro-silane treatments accentuated acidity, while amino-silane treatment produced net basicity in the fiber surface. Modification with maleated polypropylene reduced specific interactions and converted the fiber to a predominantly dispersion-force solid. The modified fibers were used in composites with polypropylene (neutral), polystyrene (base), and chlorinated polyethylene (acid) as matrix. Stress/strain and dynamic mechanical parameters were found to vary with acid/base interactions between polymer and fiber, significant improvements being noted in elastic and storage moduli, in tensile strength and elongation. In polypropylene, properties were unaffected by acid/base considerations. Acid/base forces, not necessarily dominant, merit consideration in the design of surface modification strategies intended to optimize composite mechanical properties.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pc.750140602
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Properties of γ-irradiated compostions based on polyvinyl chloride (1989)
    Brookfield, Conn. : Wiley-Blackwell
    Journal of Vinyl and Additive Technology 11 (1989), S. 81-83 
    Details
    ISSN: 0193-7197
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A Co-60 source was used to irradiate compositions based on PVC, and containing plasticizer additives including DIDP and TOTM, and chlorinated PE (CPE). Polyfunctional acrylic monomers were used as crosslinking agents, and irradiation dosages to about 8Mrad were applied to crosslink the compounds. Analyses included crosslink density estimates from solvent swelling data, and stress/strain evaluations of mechanical responses. It was shown that plasticizers reduce the crosslinking efficiency of irradiation, TOTM being the better inhibitor. The presence of CPE counteracts the trend. Mechanical properties differentiate strongly between the use of difunctional and trifunctional crosslinking agents. The latter produce networks at higher dosages (Eq 〉 4Mrad) characterized by two apparent yield stresses. This suggests the presence of two (or more) distinct network structures. DSC scans of partially crosslinked samples support the contention. The work indicates the importance of composition-property relationships in multicomponent vinyl systems.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/vnl.730110207
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Interaction effects and property retention in poly(vinyl chloride) compoundsPaper presented in part at 31 International Wire and Cable Symposium, Cherry Hill, PA, 1982. (1984)
    Brookfield, Conn. : Wiley-Blackwell
    Journal of Vinyl and Additive Technology 6 (1984), S. 13-17 
    Details
    ISSN: 0193-7197
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The influence of thermodynamic interactions among the components of a polymer system on mechanical properties and their retention on aging has been investigated. The systems considered involve plasticized poly(vinyl chloride)(PVC), and CaCO3 fillers. Inverse gas chromatography was used to measure interaction parameters, and to express these in terms of acid-base concepts. Interaction data were obtained over a wide temperature range. It was shown that the volume of plasticizers retained by the PVC correlates with the measured interaction parameters. Similarly, the interaction parameters identify a CaCO3 filler preferred for reinforcing rigid PVC, and a different CaCO3 filler for use in given PVC-plasticizer combinations. The mechanical properties of filled PVC (up to 40 phr CaCO3), and particularly the ultimate properties of the compounds, correlate with interaction concepts, as do property retention data after accelerated aging of the compounds at 100°C. It is concluded that component interaction parameters may provide useful guidelines to the formulation of compounds with superior properties and reduced property losses due to aging.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/vnl.730060106
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Mica as filler for PVC compounds: Effects of particle size and surface treatment (1984)
    Brookfield, Conn. : Wiley-Blackwell
    Journal of Vinyl and Additive Technology 6 (1984), S. 147-151 
    Details
    ISSN: 0193-7197
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In this study, natural, delaminated and silane-treated micas were screened to give fractions passing 60 to 325 screen mesh sizes. The micas were used as fillers (to 80 wt. percent) in plasticized PVC compounds, their dispersion behavior and their effects on mechanical properties of compounds being noted, and compared with the performance of similarly compounded PVC with CaCO3 fillers. The fusion and dispersion performance of these solids was contrasted strongly. While fusion time and maximum torque in Brabender mixing responded only weakly to the presence of CaCO3, in the presence of ≳40 wt. percent mica both of these parameters increased sharply. The elastic modulus of filled compounds indicated little reinforcement by CaCO3, while mica raised the modulus as much as 150 percent, suggesting significant bonding at the filler-matrix interface. This bonding appeared unable to withstand shear strain, elongations at rupture of mica-filled compounds falling catastrophically when compared with CaCO3-filled controls. The tested micas appear of questionable value as substitutes for inexpensive commodity fillers. As expected, at given loading, finer-particle micas gave increased values of the elastic modulus, but particle size did not strongly affect ultimate mechanical properties. Torque maxima and equilibria in mixing correlated well with particle size. Silane-treated micas produced compounds with properties only mildly different from those using untreated versions. Thus, in PVC (and possibly in other chloride-group containing polymers) interfacial conditions seem only mildly influenced by conventional coupling technology.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/vnl.730060405
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Polymer reprocessing: Properties of polyethylene - polyvinyl chloride mixtures (1980)
    Brookfield, Conn. : Wiley-Blackwell
    Journal of Vinyl and Additive Technology 2 (1980), S. 218-221 
    Details
    ISSN: 0193-7197
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The increasing tendency to consider waste polymers as suitable stocks for reconversion calls for guidelines as to the processing and end-product behavior of mixtures involving commodity polymers. In the present case, flow and some mechanical properties of mixtures involving low density polyethylene (PE) and filled polyvinyl chloride (PVC) were determined and used as a base-line of comparison with similar properties of multi-component mixtures involving potential compatibilizers for the incompatible matrix pair. Chlorinated polyethylene (CPE) ethylene-vinyl acetate (EVA) copolymer and ELvaloy polymeric plasticizer were the property modifiers selected. Blends were produced by roll-mill, Brabender or Banbury mixing. Flow properties were measured by capillary viscometry and solid-state properties were characterized by stress-strain data and tensile impact performance. Melt viscosities were non-linear functions of blend composition and varied significantly with the choice of compatibiliser, EVA and CPE producing greater benefits of melt strength than did Elvaloy. Elastic moduli, ultimate tensiles and tensile impact data also responded to the presence of compatibiliser, the EVA and CPE again being more effective in upgrading the properties of the incompatible matrix pair than was Elvaloy. Results, while preliminary, suggest guidelines for the composition of PE/PVC stocks with upgraded performance balance.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/vnl.730020404
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...