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  • 1
    Electronic Resource
    Electronic Resource
    FGTO — A fine structured GTO-thyristor with improved switching characteristics (1991)
    Springer
    Electrical engineering 74 (1991), S. 433-444 
    Details
    ISSN: 1432-0487
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Description / Table of Contents: Übersicht Zur Verbesserung des Schaltverhaltens ist ein feinstrukturierter GTO-Thyristor, abgekürzt FGTO, entwickelt worden. Dieses neue Bauelement hat eine Kathoden-streifenbreite von nur 20 μm und kann ohne negative Gatevorspannung bei einer Anodenstromdichte von mehr als 200 A/cm2 abgeschaltet werden. Die Abschaltzeit läßt sich durch Erhöhung des negativen Gatestroms bis zut off ≦500 ns verkürzen. Beim Abschalten von FGTOs ist keine RC-Beschaltung erforderlich. Der maximale du/dl-Wert erreicht mehr als 10 kV/μs. Zur Beschreibung des Abschalt-verhaltens von FGTOs werden analytische Modelle entwickelt, die eine gute Übereinstimmung mit den Meßergebnissen liefern.
    Notes: Contents A fine structured GTO thyristor, abbreviated FGTO, has been developed to improve the switching characteristics. The new device has a cathode finger width of only 20 μm and can be turned off without a negative gate bias at an anode current level of more than 200 A/cm2. The turn-off time can be shortened down tot off ≦500 ns by increasing the negative gate current. A snubber circuit is not necessary to turn off the FGTO's. The maximum rate of rise of anode voltage du/dl reaches more than 10 kV/μs. Analytical models are developed to describe the turn-off transients of the FGTO's. Good agreement between the theoretical and experimental results could be achieved.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01577465
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  • 2
    Electronic Resource
    Electronic Resource
    Experimental and theoretical study of the turn-off behavior of field-controlled thyristors (FCTh's) (1992)
    Springer
    Electrical engineering 75 (1992), S. 359-367 
    Details
    ISSN: 1432-0487
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Description / Table of Contents: Übersicht Es wird das Abschaltverhalten von FCTh's mit Oberflächen-Gates untersucht. Die verwendeten Bauelemente weisen Abschaltzeiten von weniger als 300 ns auf. Gemessen werden die transienten Verläufe von Anodenstrom, Gatestrom und Anodenspannung bei ohmscher und induktiver Last. Zur Beschreibung des Abschaltverhaltens werden neue analytische Modelle erstellt. Berechnungen der Abschaltverzugsphase unter Berücksichtigung transienter Gatestromverläufe und der Tailphase unter Berücksichtigung der Rekombination in derp +-Anodenzone werden durchgeführt.
    Notes: Contents The turn-off behavior of FCTh's with surface-gates is studied. The devices investigated in this paper exhibit short turn-off times of less than 300 ns. The anode current, gate voltage and anode voltage are measured under resistive and inductive load. Analytical models are developed to describe the turn-off transients of the FCTh's. Studies of the storage phase including the time-dependent gate current and the tail period including the recombination in thep +-anode region have been perfomed by applying the new models.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01576106
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  • 3
    Electronic Resource
    Electronic Resource
    Background subtraction algorithms for videodensitometric quantification of coronary stenosis (1988)
    Springer
    Machine vision and applications 1 (1988), S. 155-162 
    Details
    ISSN: 1432-1769
    Keywords: stenosis ; videodensitometry ; digital radiography ; background subtraction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract The determination of percent stenosis of coronary arteries is an important task in medicine. In this paper we discuss three different algorithms which can be used in conjunction with videodensitometry to measure this quantity. These algorithms may be used in subtracting the background under a vessel segment thus eliminating the need for a preinjection mask. Mathematical details of the algorithms and experimental results are presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01213002
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  • 4
    Electronic Resource
    Electronic Resource
    Phylogenetic calibration of the 5′ terminal domain of large rRNA achieved by determining twenty eucaryotic sequences (1988)
    Springer
    Journal of molecular evolution 28 (1988), S. 113-124 
    Details
    ISSN: 1432-1432
    Keywords: rRNA ; Eucaryotes ; Phylogeny ; Sequences
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Due to their high information content and their particular mode of variation, large rRNA molecules potentially represent powerful indicators of phylogenetic relationships. Even partial sequences may suffice to generate reliable estimations, provided they correspond to well-chosen portions of the molecule. We have systematically analyzed a specific portion of the large rRNA (the region extending over nearly 400 nucleotides from the 5′ end) as a general index of eucaryotic phylogeny. By means of fast and direct rRNA sequencing, we have determined the sequence of this region for 20 additional eucaryotes, including several representatives of each vertebrate class, an invertebrate metazoan (mussel), a fungus (Schizosaccharomyces pombe), and three higher plants. Comparative treatment of these new data and previously reported rRNA sequences shows that this region can serve as an indicator of eucaryotic phylogeny for evaluating both long-range and short-range relationships. Its conservative domains appear to possess a rather uniform rate of nucleotide changes in all the eucaryotic lineages analyzed and the phylogenetic tree we derived agrees with classical views.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02143502
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  • 5
    Electronic Resource
    Electronic Resource
    Very Negative Potential for Half-inactivation of, and Effects of Anions on, Voltage-dependent Sodium Currents in Acutely Isolated Rat Olfactory Receptor Neurons (2000)
    Springer
    The journal of membrane biology 175 (2000), S. 123-138 
    Details
    ISSN: 1432-1424
    Keywords: Key words: Olfactory receptor neuron — Sodium currents — Fluoride — Phosphate — Acetate — Patch clamp
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract. Previous measurements with CsF pipette solutions using whole-cell patch-clamp techniques in dissociated rat olfactory receptor neurons (ORNs) indicated that the sodium currents had very negative inactivation characteristics with the implication that the cell resting potential must also normally have a very negative value. This study supports the conclusions that such an effect was real and not dependent on either the nature of the pipette anions or the recording situation previously used. For all pipette solutions, sodium currents showed a threshold activation ≈−80 mV and half-maximal activation voltages ≈−55 with half-inactivation potential ≤−100 mV, without being significantly affected by the replacement of F− by other pipette anions (H2PO− 4 and acetate−) or the addition of nucleotides and glutathione (which did cause a very slight positive shift). F−, followed by H2PO− 4 and to a much lesser extent by acetate−, was the most favorable pipette anion for obtaining good seals and whole-cell sodium currents in these extremely small ORNs. These results implied that resting potentials, for viable responsive cells, should be more negative than about −90 mV, as supported by the observation that action potentials could only be evoked from holding potentials more negative than −90 mV.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002320001061
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  • 6
    Electronic Resource
    Electronic Resource
    Ion Permeation and Selectivity of Wild-Type Recombinant Rat CNG (rOCNC1) Channels Expressed in HEK293 Cells (2000)
    Springer
    The journal of membrane biology 178 (2000), S. 137-150 
    Details
    ISSN: 1432-1424
    Keywords: Key words: Recombinant rat cyclic nucleotide-gated channel (rOCNC1) — Selectivity — Permeation — Cation — Patch clamp
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract. The permeation properties of adenosine 3′, 5′-cyclic monophosphate (cAMP)-activated recombinant rat olfactory cyclic nucleotide-gated channels (rOCNC1) in human embryonic kidney (HEK 293) cells were investigated using inside-out excised membrane patches. The relative permeability of these rOCNC1 channels to monovalent alkali cations and organic cations was determined from measurements of the changes in reversal potential upon replacing sodium in the bathing solution with different test cations. The permeability ratio of Cl− relative to Na+ (P Cl /P Na ) was about 0.14, confirming that these channels are mainly permeable to cations. The sequence of relative permeabilities of monovalent alkali metal ions in these channels was P Na ≥P K 〉 P Li 〉 P Cs ≥P Rb , which closely corresponds to a high-strength field sequence as previously determined for native rat olfactory receptor neurons (ORNs). The permeability sequence for organic cations relative to sodium was P NH3OH 〉 P NH4 〉 P Na 〉 P Tris 〉 P Choline 〉 P TEA , again in good agreement with previous permeability ratios obtained in native rat ORNs. Single-channel conductance sequences agreed surprisingly well with permeability sequences. These conductance measurements also indicated that, even in asymmetric bi-ionic cation solutions, the conductance was somewhat independent of current direction and dependent on the composition of both solutions. These results indicate that the permeability properties of rOCNC1 channels are similar to those of native rat CNG channels, and provide a suitable reference point for exploring the molecular basis of ion selectivity in recombinant rOCNC1 channels using site-directed mutagenesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002320010021
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  • 7
    Electronic Resource
    Electronic Resource
    Phyletic relationships of protein structures based on spatial preference of residues (1993)
    Springer
    Journal of molecular evolution 36 (1993), S. 67-78 
    Details
    ISSN: 1432-1432
    Keywords: Structure-based scoring matrix MDPRE ; Phyletic relationship of protein structure ; Spatial preference factor ; Sequence alignment ; Protein homology detect ; Globins ; Immunoglobulins ; Cytochromes c ; Serine proteinases ; Dinucleotide-binding domains
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A structure-based scoring matrix MDPRE was derived from amino acid spatial preferences in protein structures. Sequence alignment and evolutionary studies by using MDPRE matrix gave similar results as those from ordinary sequence and structure alignments. It is interesting that a matrix derived from structure data solely could give comparable alignment results, strongly indicating the intimate connection between protein sequences and structures. The branch order and length from this approach were close to those obtained by a structure comparison method. Thus, by applying this structure-based matrix, the trees obtained should reflect evolutionary characteristics of protein structure. This approach takes advantage over a direct structure comparison in that (1) only a sequence and MDPRE matrix are needed, making it simple and widely applicable (especially in the absence of 3-dimensional protein structure data); (2) an established algorithm for sequence alignment and tree building could be employed, providing opportunities for direct comparison between matrices from different methodologies. One of the most striking features of this method is its capability to detect protein structure homologies when the sequence identities are low. This was well reflected in the given examples of the alignment of dinucleotidebinding domains.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02407306
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  • 8
    Electronic Resource
    Electronic Resource
    Factorizations in the elementary Abelian p-group and their cryptographic significance (1994)
    Springer
    Journal of cryptology 7 (1994), S. 201-212 
    Details
    ISSN: 1432-1378
    Keywords: Automorphism ; Homomorphism ; Factorization ; Transversal factorization ; Translation ; Coset representatives
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract Let G be a finite group and let A i 1 ≤ i ≤ s, be subsets of G where ¦A i ¦ ≥ 2, 1 ≤ i ≤ s and s ≥ 2. We say that (A1, A2,..., A3) is a factorization of G if and only if for each g ε G there is exactly one way to express g = a 1 a 1 a 2··· a 3, where a j ε A i , 1 ≤ i ≤ s. The problem of finding factorizations of this type was first introduced by Hajos [3] in 1941. Since then a number of papers have appeared on the subject. More recently, Magliveras [6] has applied factorization of permutation groups to cryptography to obtain a private-key cryptosystem. Factorizations in the elementary abelian p-group were exploited (but not explicitly stated in these terms) by Webb [13] to produce a public-key cryptosystem conceptually similar to cryptosystems based on the knapsack problem. Using the result that certain types of factorizations in the elementary abelian p-group are necessarily transversal (a term introduced by Magliveras), this paper shows that the public-key system proposed by Webb is insecure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00203963
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  • 9
    Electronic Resource
    Electronic Resource
    Fragile site and interstitial telomere repeat sequences at the fusion point of a de novo (Y;13) translocation (1996)
    Springer
    Human genetics 〈Berlin〉 98 (1996), S. 323-327 
    Details
    ISSN: 1432-1203
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract We describe a novel fragile site in a rearranged chromosome, associated with the presence of telomeric repeat sequences at the fusion point of a translocation between chromosomes 13 and Y. The case reported in this study shows a de novo (Y;13) translocation, which appears to represent fusion of an apparently intact chromosome Y with a chromosome 13 that has lost only part of its short arm. Ten percent of the cells show a normal karyotype without the (Y;13) translocation. Molecular cytogenetic studies of the derived Y;13 chromosome revealed three hybridization sites of the telomeric probes – one at each end and one at the breakpoint junction. A fragile site is also observed in the intrachromosomic telomeric region. This coincidence suggests that the telomere repeat sequences (TTAGGG)n, when present at an interstitial chromosomal location, can promote the formation of a novel fragile site.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004390050216
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  • 10
    Electronic Resource
    Electronic Resource
    On the simulation of the transient temperature field or some viscoelasticity problems by structural analysis program (1994)
    Springer
    Acta mechanica solida Sinica 7 (1994), S. 165-171 
    Details
    ISSN: 0894-9166
    Keywords: structural analysis program ; transient temperature field ; analogy ; viscoelasticity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract An idea is presented to solve the parabolic differential equation by the hyperbolic differential equation. We can simulate and compute the transient temperature field problems by a structural analysis program. Using only a single structural analysis program, the users can compute both temperature and thermal stress distributions on the same finite element mesh. The method thus extends the application of the structural analysis programs which have been implemented widely. As an example, the transient temperature field problem of a square plate is computed. The result is consistent with the theoretical result. A similar method for simulating some viscoelasticity problems of Kelvin model is also presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02207124
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