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
  • 1
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Analytica Chimica Acta 277 (1993), S. 325-331 
    ISSN: 0003-2670
    Keywords: FUMI ; Information theory ; Liquid chromatography ; Mutual information function ; Titrimetry
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 37 (1985), S. 153-164 
    ISSN: 1432-0630
    Keywords: 86.30 ; 72.40 ; 73.60
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract We have made theoretical studies on the trapping and recombination of photogenerated carriers in hydrogenated amorphous silicon (a-Si∶H) p-i-n solar cells. We discuss in detail the following points: 1) The limitations of the assumptions in the previous analysis. It has been clarified that the single-level Shockley-Read-Hall model for carrier recombination and the treatment of trap occupation in terms of quasi-Fermi levels are inadequate for exact analysis. 2) The superlinear dependence of carrier recombination rate on the free-carrier density which can explain the enhancement of photo-induced changes ina-Si∶H under high intensity light. 3) The estimation of capture cross section of the tail states ina-Si∶H. We show that the charged and neutral tail states have rather small capture cross sections of less than 10−16 cm2 and of less than 10−19 cm2, respectively. 4) The effect of the recombination of photogenerated (PG) carriers at the p/i and the n/i interfaces. We estimate the recombination velocityS of PG carriers at these interfaces to be about 103 cm/s. It has been also clarified that the decrease inS is effective to improve the cell performance, especially the open circuit voltage.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 40 (1986), S. 171-176 
    ISSN: 1432-0630
    Keywords: 73.60 ; 71.20 ; 86.30
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract We have reexamined the validity of quasi-static capacitance-voltage (C-V) measurements when applied to hydrogenated amorphous silicon (a-Si: H) diodes. Displacement currents with the application of a linear ramp voltage to an a-Si:H Schottky diode exhibit a slow response with time constants ranging 0.1–1 s which cannot be measured completely by the conventional measurements. The measured capacitance and the effective density of gap states obtained from the measurement depend on the timing of current observation even when the small value of the order of 0.01 V/s is chosen for the ramp rate. We propose a possible means to realize the true quasi-staticC-V measurement of a-Si:H diodes.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1432-0630
    Keywords: 86.30 ; 72.40
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract We have made theoretical studies on the limitation of the open-circuit voltageV oc of a hydrogenated amorphous silicon (a-Si:H) p-i-n type solar cell. The effects of the tail states in the a-Si:H i layer and of the interface recombination are discussed in detail. The opencircuit voltage increases when the distribution of the tail states is sharp and/or the capture cross sections of these states are small. This is because the recombination rate of photogenerated carriers and/or the density of space charge due to trapped carriers in these states become low in these conditions. These effects of the tail states on the value ofV oc become pronounced when the built-in potential of the p-i-n junction is high. The decrease in the effective recombination velocity of carriers at the p/i and n/i interfaces results in an increase ofV oc. This increase becomes remarkable when the effects of the tail states on the value ofV oc are small. Both the sharp distribution of tail states and the small value of the interface recombination velocity are necessary to increase considerably the value ofV oc. We show the conditions of the material parameters necessary to obtain an open-circuit voltage of 1.0 V.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 29 (1990), S. 446-448 
    ISSN: 1612-1112
    Keywords: Chromatography, general ; Optimization ; Information theory ; Kalman filter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The quality of a chromatogram can be numerically characterized by a set of the information functions (Φ, δΦ, ΔΦ) where Φ is called FUMI, δΦ is the information loss, and ΔΦ is the information variation. A chromatogram can be expressed as a point in the space (Φ, δΦ, ΔΦ) and change in a parameter such as wavelength shift draws a curved line in the space. Optimization processes of different parameters display different patterns of lines in the space. Two types of optimization in the space are demonstrated for the analysis of an antipyretics mixture by liquid chromatography. The method used here may lead to a new aspect of optimization theory in chromatography.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 37 (1993), S. 149-155 
    ISSN: 1612-1112
    Keywords: General chromatography ; Optimization ; Information theory ; Optimized resolution ; MEKC
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The influences of micelle concentration, applied voltage and temperature on the precision and throughput of analysis are studied. The precision is the Shannon mutual information and the throughput is the transmission speed of the information (=information divided by analysis time). The dependence of the precision and throughput on the peak shape, resolution Rs and run time is examined in various operating conditions. The most precise analysis (indicated by the maximum of the information) and the highest throughput analysis (the maximum of the transmission speed) are selected and their analytical importance is discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Optimization of variables ; Information theory ; Kalman filter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The following chromatographic variables are totally optimized based on the recently developed information theory of optimization: mobile phase composition, column length, flow rate, wavelength, and the amount of internal standard. The optimal internal standard is selected from among six candidates. Two types of optimal conditions (Φ- and ϑ-optimals) are proposed: the Φ-optimal is defined as the most precise analysis (the maximal Φ) while the ϑ-optimal is the most efficient (rapid) analysis (the maximal ϑ). The observation times for the determination of an antipyretics mixture (three components) in liquid chromatography are ca. 50 s for the ϑ-optimal and ca. 8 min for the Φ-optimal. The reliability of the Φ- and ϑ-optimals is verified by experiments.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 30 (1990), S. 171-175 
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Optimization of variables ; Information theory ; Kalman filter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A chromatographic system set at an operating condition takes its own precision and efficiency which are numerically described by the information Φ called FUMI and the information flow ϑ, respectively. Optimization for a variable such as mobile phase composition draws a line in the Φ-ϑ space. This paper demonstrates that optimization of different variables displays different patterns of lines in the Φ-ϑ space. The variables examined here are mobile phase composition, column length, flow rate (velocity) and detection wavelength (or the amount of internal standard). Clear difference in the analytical roles of the variables can be known from the Φ-ϑ plots.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 30 (1990), S. 371-376 
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Optimization of variables ; Information theory ; Kalman filter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The analytical roles of chromatographic variables (column length, etc.) can be soundly comprehended and compared in terms of the precision (Φ) of measurements and efficiency (ϑ) of analysis which are described as Shannon information and information flow, respectively. The φϑ plots of the optimization process and the information Φ transmitted by a single peak are useful to understand the analytical structure of optimization. Variables treated here are mobile phase composition (X), column length (L), mobile phase velocity rate (u), detection wavelength (λ) and plate number (N).
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 30 (1990), S. 367-370 
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Optimization of variables ; Information theory ; Kalman filter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A simple optimization method based on the well-known Rs-minimum method and on the information theory of FUMI Φ is proposed. Resolution (Rs), peak area and height (or width) are the only parameters necessary for the calculation of the information Φ and information flow ϑ. The most precise analysis can be selected as the chromatogram having maximal ϑ. Mobile phase composition, column length, flow rate, detection wavelength, amount of internal standard, etc. can be optimized by this method.
    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...