ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 25 (1991), S. viii 
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Acta Polymerica 42 (1991), S. 339-340 
    ISSN: 0323-7648
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 0323-7648
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Polyacrylnitril-Membranen werden nach drei unterschiedlichen Membranbildungsprinzipien hergestellt. Die nähere Charakterisierung der Struktur der trennaktiven Schichten erfolgt anhand von Parametern der Trennkurven und der daraus berechneten Porengrößenverteilungen, wobei eine logarithmische Normalverteilung zugrunde gelegt wird. Bei konstanten Meßbedingungen werden vergleichende Betrachtungen der strukturellen Besonderheiten der trennaktiven Begrenzungsschicht von PAN-Bikomponentenmembranen und zwei unterschiedlich hergestellten PAN-Monokomponentenmembranen angestellt und anhand von Parametern der Trennkurven oder der Porengrößenverteilung diskutiert.
    Notes: Polyacrylonitrile membranes are prepared using three different membrane preparation principles. Characterization of the structure of the skin layer is carried out in more detail by parameters of separation curves and their pore size distribution function, the former being based on a logarithmic normal distribution. Under constant conditions of measurement, comparing considerations are reflected about the structure of the separating active layer of PAN bicomponent membranes and two differently prepared PAN monocomponent membranes. The parameters of the separation curves and pore size distributions are discussed.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 43 (1991), S. 1171-1180 
    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: The relationship of 10 basic physico-mechanical properties and the concentration of the filler is investigated through narrow filling intervals of seven different composite series containing various types of HD polyethylene and different grades of kaolin. A variety of mixing techniques for the preparation of the composites is used, and testing is carried out by applying different techniques and conditions. The investigations show that, in all cases when an identical mixing technique is applied for a given series of composite formulations, the relationship linking the physico-mechanical and dynamic-mechanical G′, G″, and tan δ properties with the concentration of the filler is not a monotonous curve, and displays a multiextermal character. We propose as one possible explanation that a periodic change in the free volume and the content of crystal polyethylene phase exists, as a function of the filling. The nonmonotonous character of the changes of properties is related to the proposed mechanism for the change of the physical structure of composites, which are composed of filler particles coated with n monolayers of polyethylene crystallites, when, as filling continues, periodically new types of filler particles are formed. The nonmonotonous character of the relationship between the properties and the concentration of the filler should be taken into consideration when these relationships are approximated or expressed in a mathematical-analytical form, especially when high amounts of fillers (more than 20 vol %) are used.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 0935-6304
    Keywords: Micropacked liquid chromatography ; Enantiomer separation ; HPLC-TID ; Organophosphorus pesticides ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Microcolumn liquid chromatography (micro-LC) of some chiral organophosphorus pesticides has been studied using Chiralcel OD columns and simultaneous ultraviolet (UV) and phosphorus selective detection, the latter by means of a micro-UV cell coupled on-line to a thermionic detector (TID). Micro-LC showed a ca. 5-fold improved separation impedance, a ca. 1.8-fold increased column permeability, and greater inertness compared with conventional LC.By using the TID, organophosphorus pesticides could be satisfactorily determined at trace levels, the detection limit being 4 pg/s of phosphorus. The response of the micro-LC-TID system is linear in the range of 0.05-20 ng (r = 0.9994).
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 14 (1991), S. 475-480 
    ISSN: 0935-6304
    Keywords: Coupled RPLC-GC ; Partially concurrent solvent evaporation ; Trapping column ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new technique for coupling reversed-phase liquid chromatography (RPLC) with gas chromatography is described. A fraction eluting from an RPLC column is trapped on a short column packed with polymeric adsorbent. After the mobile phase has been displaced with water, the analytes are desorbed with ethyl acetate. Following a delay time to enable the water to be flushed to waste, the ethyl acetate containing the analytes is introduced into the gas chromatograph under conditions suitable for partially concurrent solvent evaporation, i.e. below the solvent boiling point and at a rate just exceeding the evaporation rate. Post-column addition of water to the RPLC eluent helps to prevent breakthrough of compounds which are only modestly retained on the trapping column. The relationship between the capacity factors of the analytes on the trapping column and the required dilution factor is discussed. Polycyclic aromatic hydrocarbons are used as test compounds to study the system.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 0935-6304
    Keywords: LC-GC ; Aqueous samples ; Solid phase extraction ; Thermal desorption ; PTV ; Tenax GC© ; Reversed phase adsorbent ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new approach to the introduction of large aqueous samples into a gas chromatograph, solid phase extraction - thermal desorption, is presented. Carrier gas pushes the sample through a packed liner mounted in a programmed temperature vaporizer; analytes retained by the packing material are thermally desorbed after drying of the adsorbent. The sorption properties and thermal stability of some packing materials have been studied off-line. Tenax GC®, and octyl-modified silica silylated with diphenyltetramethyldisilazane to improve its thermal stability, appeared to be suitable materials.The drying period and the desorption temperature are critical for satisfactory performance of the method. When Tenax GC® is used as packing material, thermal desorption at 250°C for 15 min gives quantitative recovery for methyl esters up to hexacosanoic acid methyl ester. With the silylated octyl-modified silica, the application range is limited to the methyl esters of decanoic to octadecanoic acids.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 0935-6304
    Keywords: HR-GC ; Organochlorine pesticides ; Pyrethroids ; Water analysis ; Sample clean-up ; Solid-phase extraction cartridges ; LC-GC ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The ASPEC (Automatic Sample Preparation with Extraction Columns) system has been coupled on-line to capillary GC-ECD by means of a loop-type interface equipped with a solvent vapour exit. Both ASPEC and GC conditions have been optimized leading to an effective clean-up of the extracts analyzed.By means of solid-phase extraction cartridges filled with silica, it has been possible to analyze concentrated surface water extracts for a group of 18 electron-capturing compounds present in the water at ppt levels. ASPEC-GC has also been applied to the determination of synthetic pyrethroids at ppt levels in surface water.The complete analytical procedure is greatly facilitated by automation and miniaturization. Miniaturization results in a considerable decrease in the sample volume required. The potential of the method for the analysis of other pesticides is estimated.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 31 (1991), S. 813-825 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Photon correlation spectroscopy has been used to study the translational (D0)and internal dynamics of monodisperse linear and polydisperse superhelical plasmid-DNAs. Scattering vector dependent correlation functions were measured and analyzed with the inverse Laplace transform CONTIN written by S. Provencher. For scattering vectors (q) lower than 1.3 × 105cm-1, D0 can be separated from internal dynamics. Using the measured D0value, the q dependence of internal modes was determined. Extrapolation of the internal relaxation times for q → 0 yields the longest internal relaxation time t1. This time can be connected to the persistence length in terms of the Berg-Soda model, which describes the molecule as a semiflexible circular polymer with hydrodynamic interactions. The calculated length of 76 nm for DNA, I = 0.15 mol/L, is a little higher than the one obtained from static light scattering data without excluded volume corrections. A comparison of experimental and simulated correlation functions for the Berg-Soda model shows that the model gives a fairly good description of the dynamics of the linear molecule, whereas large discrepancies between model and experimental functions are observed for the superhelical DNA. Small differences between model and experimental functions are mainly attributed to the neglect of the torsional modes that may be coupled to bending and flexing modes. For the superhelical DNA the agreement is improved if the calculation is carried out with a linear molecule, with shorter contour length and increased diameter. Both quantities can be derived from the known superhelix tilt angle.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 25 (1991), S. VIII 
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...