ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
    Photoreflectance study of surface Fermi level in molecular beam epitaxial grown InAlAs heterostructures (1994)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 64 (1994), S. 3314-3316 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have studied the band gaps and the surface Fermi level positions of a series of In1−xAlxAs surface-intrinsic-n+ structures at room temperature by photoreflectance. Experiments demonstrated that over aluminum concentrations of 0.42–0.57, the surface Fermi level is not pinned at midgap, as commonly believed, but instead varies, respectively, from 0.50±0.01 to 0.81±0.01 eV below the conduction band edge.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.111294
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    ROLE OF NITRITE IN CURED MEAT FLAVOR: CHEMICAL ANALYSIS (1980)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of food science 45 (1980), S. 0 
    Details
    ISSN: 1750-3841
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Hams treated with 2.5% salt and varying concentrations of sodium nitrite, butylated hydroxytoluene (BHT), and citric acid were evaluated by means of thiobarbituric acid (TBA) values, formation of fluorescent products, hexanal and 2,4-decadienal, and sensory analyses. Results demonstrate that nitrite significantly reduces (p 〈 0.05) lipid oxidation in pork stored aerobically at 4°C. Meat treated with 0.02% BHT or 1000 mg/kg of citric acid also reduced TBA values, although these compounds were not as effective as 50 mg/kg of sodium nitrite. A significant relationship (p 〈 0.05) was established between off-odor/flavor formation and both TBA values and the production of fluorescent products during the first 7 days of storage. However, the relationship between fluorescent products and off-odors/flavors was not significant at 14 days. Significantly lower (p 〈 0.05) levels of hexanal and 2,4-decadienal were found in meat treated with nitrite, BHT or citric acid compared to samples containing only salt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2621.1980.tb07472.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Comparison of Volatiles Produced by Selected Pseudomonads on Chicken Skin (1983)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of food science 48 (1983), S. 0 
    Details
    ISSN: 1750-3841
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Four pseudomonad cultures (one P. putida, one nonpigmented, and two P. fluorescens) were isolated from spoiled chicken breasts held at 2–6°C for 14 days. Each culture was grown on psychrotroph-free chicken skin for 14 days at 2–6°C. The volatiles produced by each organism were separated by high-resolution gas chromatography and identified by mass spectrometry. Some of the more significant volatile spoilage compounds produced by these microorganisms were sulfur-containing, e.g. methanethiol, dimethyl sulfide, propylene sulfide, and dimethyl disulfide.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2621.1983.tb09233.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Impact of Soy Protein Isolates and Specific Fractions on Rancidity Development in a Cooked, Refrigerated Beef System (1991)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of food science 56 (1991), S. 0 
    Details
    ISSN: 1750-3841
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Adding 0, 8, 16 and 24% soy isolate to a cooked, refrigerated beef system decreased TBA values proportionately. The impact of specific crude soy protein fractions on development of rancidity (TBA values) was investigated. The 7S, 9S and 11S protein fractions, a whole protein isolate produced from the same flakes, and the same commercial soy isolate as used previously were incorporated at the 24% or equivalent level. All additions had significant (P〈0.05) antioxidant effect. The commercial isolate and the laboratory-produced whole isolate exhibited the most antioxidant activity. The 7S and the 9S fractions contributed significant (P〈0.05) antioxidant activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2621.1991.tb08008.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Bioanalytical application of multidimensional open tubular column supercritical fluid chromatography (1993)
    Springer
    Chromatographia 35 (1993), S. 363-371 
    Details
    ISSN: 1612-1112
    Keywords: Supercritical fluid chromatography ; Open tubular columns ; Bioanalytical application
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary On-line multidimensional open tubular column supercritical fluid chromatography (SFC/SFC) using either a flow-switching or a rotary valve-switching interface has been applied to bioanalytical problems. These include the analysis of (a) cholesterol in dried egg yolk, (b) retinoic acids in rat serum, and (c) a digitalis-like factor in peritoneal dialysate from hypertensive patients. A solvent vent injection technique was incorporated in the system, allowing single or multiple volumes of extract (up to 2.0 μL each) to be injected into an uncoated, but deactivated, length of capillary precolumn without flooding of the analytical column. For flow-switching, a well-deactivated, glass-lined offset-cross with a small dead volume was placed between the primary and the secondary column. With a rotary valve-switching interface, a cold trap was employed for refocusing analytes at low pressure from single or multiple fractional cuts after being transferred to the second dimension.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02278586
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Characterization of some new polysiloxane stationary phases by principal component analysis (1994)
    Springer
    Chromatographia 38 (1994), S. 227-231 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Stationary phase characterization ; Principal component analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary In this study, several new stationary phases were characterized by principal component analysis. Fourteen new stationary phases, including substituted phenyl and oligoethyleneoxide functionalities on polysiloxane polymers, were tested and compared to three well known stationary phases. The main features of these phases were studied using a series of test solutes of varying chemical characteristics representing the data set for principal component analysis. Two principal compounds were found to account for 99.20% of the variance (the first accounted for 94.96% and the second for 4.24%). The data were represented as a two-dimensional map for visual representation of the characteristics of these stationary phases. The first principal component represented a selectivity based on polarity (r2=0.998), while the second showed Lewis acid-base characteristics of the phases. Polarizable and amphoteric characteristics of these phases also became evident using this evaluation method.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02290341
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The preparation of non-extractable methylphenylpolysiloxane stationary phases for capillary column gas chromatography (1982)
    Springer
    Chromatographia 15 (1982), S. 335-340 
    Details
    ISSN: 1612-1112
    Keywords: Capillary gas chromatography ; Fused silica capillary columns ; Crosslinked phenyl polysiloxanes ; Non-extractable stationary phases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The synthesis of methylphenylpolysiloxane polymers and their use in the preparation of crosslinked, non-extractable stationary phases for fused-silica capillary columns are described. By preparing more viscous phenyl-containing polymers than are commercially available, stationary phase films of these polymers could be efficiently coated on fused-silica capillary columns and stabilized by a free radical crosslinking mechanism using peroxides. Four methylphenylpolysiloxane polymers containing different phenyl concentrations were prepared. These included three polymers containing 50% phenyl and one polymer containing 70% phenyl. Two of the 50% phenyl polymers had one phenyl and one methyl group attached to each silicon atom. One of these also had 1% vinyl incorporated. The third 50% phenyl polymer was synthesized in such a way that one half of the silicon atoms had two phenyl groups attached while the rest contained dimethyl groups. The 70% phenyl polymer also had 4% vinyl incorporated. Due to the intrinsic thermal stability of these phenyl phases and the enhanced film stability achieved by crosslinking, the 70% phenyl phase could be utilized up to 400 °C. Using the methods described in this paper, highly efficient and thermally stable fused silica capillary columns coated with crosslinked methylphenylpolysiloxane stationary phases can be successfully prepared.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02259213
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Evaluation of an ion mobility detector for supercritical fluid chromatography with solvent-modified carbon dioxide mobile phases (1991)
    Springer
    Chromatographia 31 (1991), S. 163-167 
    Details
    ISSN: 1612-1112
    Keywords: Supercritical fluid chromatography ; Ion mobility detection ; Mixed mobile phase ; Molecular connectivity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary An ion mobility detector (IMD) was evaluated for open tubular column supercritical fluid chromatography (SFC) when organic solvent-modified supercritical CO2 was used as mobile phase. It was found that the SFC/IMD interface design in which the SFC capillaray restrictor was directly inserted into the ionization region of the IMD was not acceptable because of low sensitivity that resulted from the effect of the modifier on detector temperature and mechanism of detection. A new interface utilizing a heated nebulizer gas to provide heat to the restrictor and to minimize the formation of ion clusters, and a bent nozzle for enhancing the ionization efficiency of the solute in the IMD ion source are described. Using 5% acetonitrile in CO2, the minimum detectable quantity (S/N=3) for pyrene was improved from 25.2 ng to 2.1 ng with the new detector design. This compares to a minimum detectable quantity of 0.1 ng when using neat CO2 as mobile phase. The use of molecular connectivity calculations to predict the drift times of selected analytes is also successfully demonstrated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02274566
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    On-line multidimensional open tubular column supercritical fluid chromatography using a valve-switching interface (1991)
    Springer
    Chromatographia 31 (1991), S. 233-238 
    Details
    ISSN: 1612-1112
    Keywords: Supercritical fluid chromatography ; Open tubular columns ; Multidimensional chromatography ; Valve switching
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary An on-line two-dimensional open tubular column supercritical fluid chromatograph was constructed and evaluated. A rotary valve interface allowed independent flow control of two 50-μm i.d. open tubular columns, providing maximum versatility for heartcutting. A solvent-venting injection technique was incorporated in the system that enabled single or multiple 2.0-μL volumes to be injected into an uncoated, yet deactivated, length of capillary precolumn without flooding of the analytical column. A cold trap was employed to refocussolutes from single or multiple fractional cuts after being transferred to the second dimension. The performance of the system was demonstrated with the analysis of mixtures of polycyclic aromatic compounds and steroids. Efficiencies of 4,500 plates m−1 were preserved in the second column after heartcutting.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02275742
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Demonstration of a linear composition gradient during water saturation of CO2 in supercritical fluid chromatography (1993)
    Springer
    Chromatographia 37 (1993), S. 93-97 
    Details
    ISSN: 1612-1112
    Keywords: Supercritical fluid chromatography ; Phase behavior ; Mixed mobile phases ; Water-saturated CO2 ; Steroid compounds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Water was added to CO2 by saturation to increase the solvation power of the mobile phase in supercritical fluid chromatography. The saturation was performed at a temperature above the boiling point of water (100°C) to increase the amount of water which could be loaded homogeneously into the CO2 (2.5–3.0 mol% water as compared to about 0.25 mol% water at 25°C). A linear composition of water was produced by altering the density of the CO2 during saturation. Modifications to the injector and CO2 transfer lines prevented phase separation as a result of the instrumentation used in capillary supercritical fluid chromatography (SFC). After fitting vapor-liquid equilibria data to pressure, density, and temperature conditions, approximately 2.5–3.0 mol% of water was introduced in a linear gradient at 110°C. The effect of water on SFC performance was evaluated with standard steroid compounds. This paper provides further evidence for the need to examine vapor-liquid equilibria data prior to SFC.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02272195
    Location Call Number Expected 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...