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
Filter
  • 1990-1994  (11)
  • Chemistry  (9)
  • reaction kinetics  (2)
  • Biochemistry and Biotechnology
  • 1
    Electronic Resource
    Electronic Resource
    Statics and dynamics of a diffusion-limited reaction: Anomalous kinetics, nonequilibrium self-ordering, and a dynamic transition (1990)
    Springer
    Journal of statistical physics 60 (1990), S. 695-728 
    Details
    ISSN: 1572-9613
    Keywords: Diffusion-reaction systems ; reaction kinetics ; nonequilibrium phase transitions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We solve exactly the one-dimensional diffusion-limited single-species coagulation process (A+A→A) with back reactions (A→A+A) and/or a steady input of particles (B→A). The exact solution yields not only the steady-state concentration of particles, but also the exact time-dependent concentration as well as the time-dependent probability distribution for the distance between neighboring particles, i. e., the interparticle distribution function (IPDF). The concentration for this diffusion-limited reaction process does not obey the classical “mean-field” rate equation. Rather, the kinetics is described by a finite set of ordinary differential equations only in particular cases, with no such description holding in general. The reaction kinetics is linked to the spatial distribution of particles as reflected in the IPDFs. The spatial distribution of particles is totally random, i. e., the maximum entropy distribution, only in the steady state of the strictly reversible process A+A↔A, a true equilibrium state with detailed balance. Away from this equilibrium state the particles display a static or dynamic self-organization imposed by the nonequilibrium reactions. The strictly reversible process also exhibits a sharp transition in its relaxation dynamics when switching between equilibria of different values of the system parameters. When the system parameters are suddenly changed so that the new equilibrium concentration is greater than exactly twice the old equilibrium concentration, the exponential relaxation time depends on the initial concentration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01025990
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Fluctuations and correlations in a diffusion-reaction system: Exact hydrodynamics (1991)
    Springer
    Journal of statistical physics 65 (1991), S. 953-970 
    Details
    ISSN: 1572-9613
    Keywords: Diffusion-reaction system ; reaction kinetics ; nonlinear waves
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We present an exact closed formulation of the reversible diffusion-limited coagulation-growth reactions 2A ↔ A with irreversible input B → A in one spatial dimension. The treatment here accommodates spatial as well as temporal variations in the particle density with a complete account of microscopic fluctuations and correlations. Moreover, spatial and/or temporal variations in the transport and reaction coefficients can be included in the model. A general solution to the reversible process is presented, and we explore the phenomenon of wavefront propagation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01049592
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Finding causes of outliers in multivariate environmental data (1991)
    New York, NY : Wiley-Blackwell
    Journal of Chemometrics 5 (1991), S. 241-248 
    Details
    ISSN: 0886-9383
    Keywords: Multivariate kurtosis ; Generalized distance ; Multivariate outliers ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Multivariate outliers in environmental data sets are often caused by atypical measurement error in a single variable. From a quality assurance perspective it is important to identify these variables efficiently so that corrective actions may be performed. We demonstrate a procedure for using two multivariate tests to identify which variable ‘caused’ each outlier. The procedure is tested with simulated data sets have have the same correlation structure as selected water chemistry variables from a survey of lakes in the Western United States. The success rates are evaluated for three of the variables for sample sizes of 50 and 100, significance levels of 0.01 and 0.05 and various amounts of mean shift. The procedure works best for highly correlated variables.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cem.1180050311
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Finding suspected causes of measurement error in multivariate environmental data (1993)
    New York, NY : Wiley-Blackwell
    Journal of Chemometrics 7 (1993), S. 165-176 
    Details
    ISSN: 0886-9383
    Keywords: Measurement error ; Outliers ; Environmental ; Quality control ; Multivariate kurtosis ; Generalized distance ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Environmental data are usually multivariate, with the variables conforming to some correlation structure. Occasionally, measurements which do not conform in structure or magnitude may occur in one or more variables. It is important (1) to characterize these discordancies in terms of the disturbed variables and the direction and magnitude of the anomalous error and (2) to associate each discordant observation with a specific cause of measurement error in order to prevent further mismeasurement. We describe a procedure for identifying suspected causes of discordant observations in otherwise multinormal data sets. Variables are assigned to groups, each of which is associated with a specific cause of measurement error. Discordant observations are identified with the generalized distance test or the multivariate kurtosis test. Suspected causes of measurement error are identified by repeating the tests with one of the groups of variables omitted in each analysis. The procedures are evaluated with simulated data sets having a correlation structure similar to that of a large environmental data set.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cem.1180070304
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Control of an Escherichia coli mixed culture via affinity binding (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 38 (1991), S. 380-388 
    Details
    ISSN: 0006-3592
    Keywords: control ; mixed culture ; adhesion ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A chemostat with population specific recycle was employed to alter the dynamics of a competitive mixed culture of Escherichia coli. Based on differential expression of a functional maltoporin, the two populations were separated by specific adhesion on starch-Sepharose. The slower growing population was the recycled to the reactor. The specific recycle was successful in maintaining the slower growing population at a high level than in comparable reactors without recycle.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260380408
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    A Few-Monolayer Organic RectifierThe authors gratefully acknowledge collaboration with Prof. G. J. Ashwell's Centre for Molecular Electronics at Cranfield Institute of Technology for the synthesis of the molecules and numerous invaluable discussions. The support of the Science and Engineering Research Council is also gratefully acknowledged. (1993)
    Weinheim : Wiley-Blackwell
    Advanced Materials 5 (1993), S. 580-582 
    Details
    ISSN: 0935-9648
    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
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/adma.19930050716
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Electrical breakdown and recovery in rectifying m | lb | m structures (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Advanced Materials for Optics and Electronics 1 (1992), S. 17-23 
    Details
    ISSN: 1057-9257
    Keywords: Langmuir-Blodgett ; M | LB | M ; electrical breakdown ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Metal 1 | C16H33-Q3CNQ LB film | metal 2 structures exhibiting asymmetric, non-linear I/V characteristics have been fabricated using the Langmuir-Blodgett (LB) technique with LB film thicknesses as small as a single monolayer. When such junctions are subjected to low biases, the I/V traces exhibit little or no asymmetry, but as the applied biases increase, so the I/V asymmetry becomes more evident. The largest applied voltages before breakdown are of the order of 1 V, which represents an E-field of order 108 V m-1. This breakdown under high biases increases the junction conductance and the I/V traces become very noisy. More interestingly, it has been observed that after such breakdown it is possible for the junction to recover on reduction of the bias. It is observed that recovery is not always immediate and may require several voltage sweeps. A subsequent increase in bias will cause breakdown at the same bias as the first breakdown, indicating that no permanent damage has been caused.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/amo.860010104
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Synthesis of Hydroxy Benzonitriles by heterogenous-catalytical ammoxidation of the isomeric methoxytoluenes and their mixturesHerrn Prof. Dr. sc. nat. S. Nowak zum 60. Geburtstag gewidmet (1990)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 332 (1990), S. 551-556 
    Details
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In the synthesis of p-hydroxybenzonitrile as a herbicide intermediate the nitrile formation is the most important reaction step. Possible feed compounds could be pure p-cresole, cresole mixtures or OH-protected cresoles like methoxy- or acetoxytoluenes. The ammoxidation of m- and p-methoxytoluene and a m,p-methoxytoluene-mixture over vanadium-titanium oxide catalysts has been investigated using flow reactors in a temperature range of 630-703 K. On comparable reaction conditions the conversion of pure compounds leads to a higher selectivity of p-methoxybenzonitrile (approx. 70%, conversion 85 mol-%) than that of the m-compound (only 35%, conversion 45 mol-%). For synthesis of the p-nitrile the feedstock can be p-methoxytoluene obtained by methylation of p-cresole, but it is also possible to use a m,p-methoxytoluene mixture obtained by methylation of an industrial cresole mixture. The ammoxidation of such a mixture affords a higher reactivity of the p-isomer and p-methoxybenzonitrile as the main reaction product, whereas m-methoxytoluene remains unreacted for the most part. Generally, the results obtained show that an amount of approx. 79% of the converted p-methoxytoluene was transformed into p-methoxybenzonitrile, whereas the corresponding transformation into the m-isomer was lower than 36%. An important part of the m-isomer was degraded by oxidation towards CO, CO2 and HCN.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19903320421
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Description of the mathematical law that defines the relaxation of bovine pericardium subjected to stress (1994)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 28 (1994), S. 755-760 
    Details
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: A material subjected to traction stress increases in length; if we maintain the elongation constant, the stress varies over a period of time. This phenomenon has been referred to as relaxation. The purpose of this study was to define a mathematical law that relates the variation in stress to time when elongation remains constant in bovine pericardium. The mathematical function obtained after assaying 34 samples to the point of relaxation, subjected to initial stresses ranging from 0.17-10.07 MPa, responds to the following equation: y = -0.0252 + 0.953 α - (0.0165 + 0.015 α)lnt, where γ is the stress withstood at an instant in time, t, after initial stress α. A normogram, validated by assays of up to 6,340 min duration (4.40 days), is presented for graphic calculation, permitting the computation of the loss of stress due to relaxation of this biomaterial, with initial stresses ranging from 1-10 MPa. © 1994 John Wiley & Sons, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jbm.820280613
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    De Novo Design of a Novel Heterodinuclear Three-Helix Bundle MetalloproteinThis work was supported by the Searle Scholars Program/the Chicago Community Trust and the Arnold and Mabel Beckman Foundation. We thank J. Schiffer for his contribution to the early stages of this project, Dr. D. Goodin for EPR measurements, and Drs. M. Griffith, S. Kent, and G. Siuzdak for their assistance in mass spectrometric analyses. (1993)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 32 (1993), S. 1594-1597 
    Details
    ISSN: 0570-0833
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.199315941
    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...