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Showing papers by "Karlsruhe Institute of Technology published in 1985"



Journal ArticleDOI
TL;DR: In this paper, a new way is proposed to determine modified AOs and to characterize hypervalent contributions, based on occupation numbers, originally proposed by Davidson, is briefly reviewed.
Abstract: The population analysis based on occupation numbers, originally proposed by Davidson, is briefly reviewed. A new way is proposed to determine modified AOs and to characterize hypervalent contributions. This is discussed in application to the molecules NSF, NSF3, SF6, OPCl, OPCl2, O2PCl, SO2, ClO 4 − . It is the main objective of this work to investigate the connection between shared electron numbers σ — considered as a measure of covalent bond strength — and bond energies, σ is found to be a reliable measure of bond energies.

225 citations


Journal ArticleDOI
01 Jan 1985-Planta
TL;DR: The lipid composition of whole leaves and isolated plastoglobul of beech (Fagus sylvatica) has been studied during four natural autumnal senescence stages and the main constituents of thylakoids, glycolipids and proteins, were not deposited in plastsoglobuli and therefore did not play an important role in plastglobuli metabolism.
Abstract: The lipid composition of whole leaves and isolated plastoglobul of beech (Fagus sylvatica) has been studied during four natural autumnal senescence stages. Chlorophylls, glycolipids, and phospholipids were extensively degraded in leaves. About 20% of the glycolipids found in leaves during summer, however, remained in the last stage of leaf senescence. Triacylglycerols, also detected in large amounts in summer leaves, were hydrolyzed during senescence. The content of free fatty acids derived from degradation of glycerolipids therefore increased. The total carotenoid and prenyl quinone content was largely unchanged during senescence, except during the last stage investigated, but the reduced forms of prenyl quinones decreased while the oxidized prenyl quinones increased. Plastoglobuli isolated from summer leaves mainly contained triacylglycerols, plastohydroquinone, and α-tocopherol. The triacylglycerol content declined in plastoglobuli during senescence. Most of the triacylglycerols must be located outside the plastoglobuli throughout the stages investigated. Carotenoids liberated from thylakoids were esterified and increasingly deposited in plastoglobuli during senescence. In the last senescence stage, carotenoid esters were the main component of plastoglobuli. Prenyl quinones were also transferred into plastoglobuli. Reduced prenyl quinones were sucessively oxidized during senescence and plastoquinone (oxidized) was the predominant prenyl quinone in plastoglobuli isolated from the last senescence stage. The carotenoid and prenyl quinone distribution was identical in leaves and plastoglobuli during late senescence. The main constituents of thylakoids, glycolipids and proteins, were not deposited in plastoglobuli and therefore did not play an important role in plastoglobuli metabolism.

223 citations


Journal ArticleDOI
TL;DR: Nitrous oxide reductase from the denitrifying bacterium Pseudomonas perfectomarina has been isolated and purified to homogeneity and several spectroscopically distinct forms of the enzyme were identified.
Abstract: Nitrous oxide reductase from the denitrifying bacterium Pseudomonas perfectomarina has been isolated and purified to homogeneity The enzyme contained about eight copper atoms/120 kDa and was composed of two presumably identical subunits The isoelectric point was 51 Several spectroscopically distinct forms of the enzyme were identified A 'pink' form of the enzyme was obtained when the purification was done aerobically The specific activity of this species was around 30 nkat/mg protein as measured by the nitrous-oxide-dependent oxidation of photochemically reduced benzyl viologen A 'purple' form of the enzyme, whose catalytic activity was 2-5-fold higher, was obtained when the purification was done anaerobically The activity of both forms of the enzyme was substantially increased by dialyzing the protein against 2-(N-cyclohexylamino)ethanesulfonate buffer at pH approximately equal to 10 A maximal activity of 1000 nkat/mg protein has been obtained for the purple form using this procedure A 'blue', enzymatically inactive form of the enzyme resulted when either the pink or the purple species was exposed to excess dithionite or ascorbate Anaerobic, potentiometric titrations of both the purple and the pink form of the enzyme gave a Nernst factor, n540, of 095 and a midpoint potential, E'0,540 of +260 mV (vs SHE, 25 degrees C, Tris/HCl buffer, pH 75) Electron paramagnetic resonance (EPR) and optical spectra of N2O reductase suggested the presence of an unusual type 1 copper center Type 2 copper was absent The hyperfine splitting in the g parallel region consisted of a seven-line pattern In the presence of excess of reductant, a broad EPR signal with g values at 218 and 206 was observed The EPR spectra of the pink and purple forms of the enzyme were similar; however, the spectrum of the purple form was better resolved with g parallel = 218 (A parallel = 383 mT) and g perpendicular = 203 (A perpendicular = 28 mT) Most of the copper in N2O reductase was removed by anaerobic dialysis against KCN Reaction of the apoprotein with Cu(en)2SO4 partially regenerated the optical and EPR spectra of the holoprotein; the resulting protein was enzymatically inactive Monospecific antibodies against the copper protein strongly inhibited the N2O reductase activity of purified samples and cell-free extracts

202 citations


Journal ArticleDOI
01 Dec 1985
TL;DR: In this article, a high pressure autoclave with sapphire windows, auxiliary equipment and means and precautions needed for experiments with high pressure, high temperature oxygen are described, and determinations were made of liquid-gas phase equilibria conditions along "isopleths" between 500 and 660 K to 250 MPa.
Abstract: A high pressure autoclave with sapphire windows, auxiliary equipment and means and precautions needed for experiments with high pressure, high temperature oxygen are described. With water-oxygen mixtures of different mole fractions, x, determinations were made of liquid-gas phase equilibria conditions along “isopleths” between 500 and 660 K to 250 MPa. Molar volumes of the mixtures were measured at the three-dimensional (PTx) phase equilibria surface and in the supercritical region at 673 K. The critical curve, an envelope for the isopleths, begins at the critical point of water (647 K), has a temperature minimum (640 K) at about 75 MPa and proceeds to 250 MPa at 663 K. Phase equilibria and critical curve data are given. The H2OO2 critical PT curve is very close to the critical curve recently (10) determined for H2ON2. Values for the Henry-constant from 300 K to 647 K for mixtures dilute in oxygen are presented. The Henry constant at room temperature has only about half the value of the Henry constant for nitrogen in water. At the critical temperature of water (647 K), however, both constants do not differ by more than the uncertainty of the determinations. The excess volume was calculated at 673 K from 30 to 250 MPa. All values are positive. The excess Gibbs energy and activity coefficients are presented. One isopleth for H2O-air with x(H2O) = 0.80 was measured and molar volume values for this composition at 673 K between 33 and 280 MPa are given.

142 citations


Journal ArticleDOI
TL;DR: The CGTO integral evaluation, SCF,SCF‐gradient, integral transformation, and MR‐CI (SD) steps of the COLUMBUS system of programs have been adapted for the CYBER 205 supercomputer.
Abstract: The CGTO integral evaluation, SCF, SCF-gradient, integral transformation, and MR-CI (SD) steps of the COLUMBUS system of programs have been adapted for the CYBER 205. A description is given of our efforts and the partly heavy modifications necessary to exploit the potential of this supercomputer and to avoid its shortcomings. Typical timings are reported, vector and scalar performance are compared.

139 citations


Journal ArticleDOI
TL;DR: The upper Proterozoic Windermere Supergroup of western Canada (800-570 Ma) contains the depositional record of a wedening rift system along the evolving passive continental margin of North America as discussed by the authors.

134 citations


Proceedings ArticleDOI
01 Jun 1985
TL;DR: The CAD-tool PROTEST (Probabilistic Testability Analysis) is presented and it is demonstrated that the fault coverage will increase and the necessary number of random patterns will drastically decrease, if each primary input is stimulated by test patterns having specific probabilities of being logical “1”.
Abstract: The CAD-tool PROTEST (Probabilistic Testability Analysis) is presented PROTEST estimates for each fault of a combinational circuit its detection probability which can be used as a testability measure Moreover it calculates the number of random test patterns which must be generated in order to achieve the required fault coverage It is also demonstrated that the fault coverage will increase and the necessary number of random patterns will drastically decrease, if each primary input is stimulated by test patterns having specific probabilities of being logical "1" PROTEST uses this fact and determines for each input the optimal signal probability for a randomly generated pattern

121 citations


Journal ArticleDOI
TL;DR: In this paper, a single-crystal structure determination of Ce2O3 has been carried out (two-circle diffractometer, Mo Kα radiation, R value 2.9% for 614 unique reflections).
Abstract: A single-crystal structure determination of Ce2O3 has been carried out (two-circle diffractometer, Mo Kα radiation, R value 2.9% for 614 unique reflections). The results are in perfect agreement with Pauling's model of the A-type sesquioxides and with the neutron powder diffraction data known for La2O3 and Nd2O3. There is no indication of the so-called micro-twinning which was found 20 years ago by means of single crystals of La2O3 and Nd2O3.

116 citations


Journal ArticleDOI
TL;DR: The Pantelleria Rift system is a wide zone of post-Miocene northwest-trending grabens and horsts beneath the Sicily Strait as mentioned in this paper, which is probably the expression of an Oligocene Miocene crustal extension event which produced continental rifts in western Europe and led to passive margin formation in the western Mediterranean.
Abstract: The Pantelleria Rift system is a wide zone of post-Miocene northwest-trending grabens and horsts beneath the Sicily Strait. The central grabens host volcanics of predominantly alkalic composition which are exposed on the islands of Pantelleria and Linosa. On the Maltese Islands, along the northeastern shoulder of the rift, an Oligocene-Miocene carbonate succession exposed above sea level allows structural analysis and determination of shallow crustal stresses within the otherwise largely submarine rift system. An older northeast-trending set of normal faults is probably the expression of an Oligocene-Miocene crustal extension event which produced continental rifts in western Europe and led to passive margin formation in the western Mediterranean. Younger northwest-trending grabens of the Pantelleria Rift system cut the older faults almost at right angles and define a zone of lithospheric stretching between Tunisia and Sicily. The northwest-trending grabens which subsided dramatically since the beginning of Pliocene time appear to be connected by east-trending dextral and, more rarely, north-trending sinistral transforms. Displacement along the transforms is probably in the order of a few kilometres. In-situ stress measurements carried out on the Maltese Islands show maximum horizontal compression (SH) parallel to the rift. This suggests that in general σ1 (vertical) and σ2 (horizontal and parallel to the rift) are of about the same magnitude; both exceed σ3 (Sh) which trends northeasterly. Slight intraplate convergence in a NW-SE direction seems to be more than balanced by extension in a NE-SW direction. Neotectonics of the region possibly reflects an asthenospheric flow pattern which became established during the Messinian salinity crisis. The mechanism of recent intraplate deformation of the Pelagian shelf has relevance for the understanding of more anciently subsided platforms of the Apulian Plate.

114 citations



Journal ArticleDOI
01 Jul 1985
TL;DR: In this paper, a high pressure autoclave equipped with sapphire windows is described, where water-nitrogen mixtures of thirteen different concentrations (x) determinations were made of liquid-gas phase equilibria conditions along "isopleths" between 523 and 673 K and 20 to 270 MPa.
Abstract: A high pressure autoclave equipped with sapphire windows is described. With water-nitrogen mixtures of thirteen different concentrations (x) determinations were made of liquid-gas phase equilibria conditions along “isopleths” between 523 and 673 K and 20 to 270 MPa. Molar volumes of the mixtures were measured at the three-dimensional (PTx) phase equilibria surface and in the supercritical homogeneous region at 673 K. The critical curve, an envelope of the isopleths, begins at the critical point of water (647 K), has a temperature minimum (639 K) at about 75 MPa and proceeds to 250 MPa at 659 K. Phase equilibria and critical curve data are given. Values for the Henry-constant to 647 K for mixtures dilute in nitrogen and for the nitrogen solubility from 300 to 600 K and from 10 to 200 MPa are presented. Excess volume, VE, values have been calculated for 673 K from 30 to 250 MPa. All VE values are positive. The maximum is 57 cm3 mol−1 at 70 mol per cent of H2O at 30 MPa and about 2 cm3 mol−1 at 40 mol per cent H2O and 250 MPa. Excess Gibbs energy-values and activity coefficients are presented.

Journal ArticleDOI
01 Jul 1985-Planta
TL;DR: The surface structure and composition of surface lipids were examined in leaves of barley, bean, and cucumber seedlings grown in a growth chamber under white light and low levels of ultraviolet (UV-B) radiation to cause an increase of total wax by about 25% in all plant species investigated.
Abstract: The surface structure and composition of surface lipids were examined in leaves of barley, bean, and cucumber seedlings grown in a growth chamber under white light and low levels of ultraviolet (UV-B; 280-320 nm) radiation. The cuticular wax of cucumber cotyledons and bean leaves appeared as a thin homogeneous layer, whereas on barley leaves crystal-like structures could be observed under these irradiation conditions. Principally, the amount of cuticular wax found in barley leaves was five times greater than in bean or cucumber leaves. The prediominant wax components were primary alcohols in barley, primary alcohols and monoesters in bean, and alkanes in cucumber cotyledons. Irradiation with enhanced UV-B levels caused an increase of total wax by about 25% in all plant species investigated. Aldehydes, detected as a minor constituent of cucumber and barley wax, increased twofold. Distribution patterns of the homologs within some wax classes were different at low and enhanced UV-B levels. In general, the distribution of the homologs was shifted to shorter acyl chain lengths in wax of leaves exposed to enhanced UV-B levels. This was most apparent in cucumber wax, less in bean or barley wax. The UV-B-caused effects upon cucumber wax were mainly due to a response by the adaxial surface of the leaf.

Journal ArticleDOI
TL;DR: In this article, a 1-1 correspondence between Euler methods and SIM's, generated by generalized Faber polynomials, is established, which gives that asymptotically optimal Euler method are quite near the optimal SIM's.
Abstract: Given a nonsingular linear systemA x=b, a splittingA=M?N leads to the one-step iteration (1)x m =T X m?1 +c withT:=M ?1N andc:=M ?1 b. We investigate semiiterative methods (SIM's) with respect to (1), under the assumption that the eigenvalues ofT are contained in some compact set Ω of ?, with 1?Ω. There exist SIM's which are optimal with respect to Ω, but, except for some special sets Ω, such optimal methods are not explicitly known in general. Using results about "maximal convergence" of polynomials and "uniformly distributed" nodes from approximation and function theory, we describe here SIM's which are asymptotically optimal with respect to Ω. It is shown that Euler methods, extensively studied by Niethammer-Varga [NV], are special SIM's. Various algorithms for SIM's are also derived here. A 1-1 correspondence between Euler methods and SIM's, generated by generalized Faber polynomials, is further established here. This correspondence gives that asymptotically optimal Euler methods are quite near the optimal SIM's.


Journal ArticleDOI
TL;DR: In this paper, the results of experimental and numerical investigations of laminar flow in a pipe with a sudden contraction in its cross sectional area were summarized in order to gain an insight into the flow structure near the sudden contraction and an understanding of increased pressure losses generated in this region.

Book ChapterDOI
01 Jan 1985
TL;DR: The initiation and maintenance mechanism of multi-cellular secondary currents in a straight wide-river is quite unknown at present as mentioned in this paper, and the existence of secondary currents over a flat bed by varying the aspect ratio of channel is investigated experimentally.
Abstract: The initiation and maintenance mechanism of multi-cellular secondary currents in a straight wide-river is quite unknown at present. This study investigated experimentally the existence of secondary currents over a flat bed by varying the aspect ratio of channel. It was suggested strongly that an initiation of cellular secondary currents may be motivated by the mutual interaction between the secondary currents and the sand bed.

Journal ArticleDOI
01 Feb 1985
TL;DR: In this article, the authors described a molecular-thermodynamic model for adsorption equilibria of a partially dissociated organic solute adsorbing onto activated carbon surfaces from dilute aqueous solution.
Abstract: The molecular-thermodynamic model described in Part I is extended to systems containing two or more solutes in aqueous solution. Calculated results are in good agreement with new experimental adsorption data for bisolute systems containing paranitrophenol/benzoic acid and aniline/benzoic acid. In Part I, we described a molecular-thermodynamic model for adsorption equilibria of a partially dissociated organic solute adsorbing onto activated carbon surfaces from dilute aqueous solution. In this work we extend that model to aqueous solutions containing two or more partially dissociated solutes.

Journal ArticleDOI
TL;DR: In this paper, an analytical potential function was derived from the ab initio data points and used in the molecular dynamics simulation of liquid N 2, and the results for the N2 dimer and the liquid state properties were compared with experimental work and other theoretical results.
Abstract: Results are reported from large ab initio calculations at the CPF level for the N2 dimer. An analytical potential function was derived from the ab initio data points and used in the molecular dynamics simulation of liquid N 2. The results for the N2 dimer and the liquid state properties are compared with experimental work and other theoretical results.

Journal ArticleDOI
15 Sep 1985
TL;DR: In this article, ground state potential curves for first-row diatomics were computed near R e for first row diataomics by of single-reference Cl(SD) and CPF.
Abstract: Ground state potential curves heve been computed near R e for first-row diatomics by of single-reference Cl(SD) and CPF (which includes cluster


Journal ArticleDOI
TL;DR: In this article, the authors presented a traveltime and relative amplitude study in the form of velocity-depth functions for each individual profile assuming horizontally flat layering, showing that the upper crust of the western Arabian Shield yields relatively high-velocity material at about 10 km depth underlain by velocity inversions.

Journal ArticleDOI
TL;DR: In this paper, a method was presented to evaluate complete v-KI curves from static bending tests, whereby no special assumptions for the type of v -KI relation are necessary, and the method permits determination of crack growth rates of <10−12m/s.
Abstract: A method is presented to evaluate complete v-KI curves from static bending tests, whereby no special assumptions for the type of v-KI relation are necessary. The method permits determination of crack growth rates of <10−12m/s.

Journal ArticleDOI
TL;DR: In this article, a complete statically admissible stress field is derived for the problem of the stability of the unsupported span of a tunnel and the solution is based on the lower bound theorem of plasticity.
Abstract: Complete statically admissible stress fields are evaluated for the problem of tunnel stability. The tunnels are supported by uniform internal pressure due to a lining or rock bolts. In both cases plane deformations are assumed. Additionally, a complete stress field is derived for the problem of the stability of the unsupported span of a tunnel. The latter problem is formulated three dimensionally. In all cases the Mohr Coulomb yield criterion is used. The solution is based on the lower bound theorem of plasticity, which states that the stability of a statical system is proved if at least one admissible stress field exists.

Journal ArticleDOI
TL;DR: An elementary proof of the Cauchy-Kowalevsky Theorem is given in this paper, where it is shown that an elementary proof can be found in the form of
Abstract: (1985). An Elementary Proof of the Cauchy-Kowalevsky Theorem. The American Mathematical Monthly: Vol. 92, No. 2, pp. 115-126.

Journal ArticleDOI
TL;DR: In this paper, the Veranderungen in den Gehalten der Aromastoffe des Weines bei der Flaschenlagerung untersucht.
Abstract: Mit Hilfe der gaschromatographisch-massenspektrometrischen Analysentechnik wurden die Veranderungen in den Gehalten der Aromastoffe des Weines bei der Flaschenlagerung untersucht. Die Untersuchungen wurden an Weinen der Rebsorte Riesling von 10 verschiedenen Jahrgangen (1964,1973–1975,1977–1982) aus dem gleichen Weingut durchgefuhrt. Ferner wurde die Aromastoffzusammensetzung eines „eingefrorenen” Rieslingweines mit der normalgelagerten („kellergelagerten”) Variante aus dem gleichen Gargebinde verglichen. Infolge der chemischen Gleichgewichtseinstellung in der wasrig-ethanolischen Losung nehmen die Gehalte der Essigsaureester (Acetate) ab, die Gehalte der Di- und Monoethylester von Dicarbonsauren zu. Ferner werden die Bildung bzw. die Gehaltszunahme von Substanzen aus dem Carotinoid-Abbau (Vitispirane, 1,1,6-Trimethyl-1,2-dihydro-naphtalin) und dem Kohlenhydrat-Abbau (Dehydratisierungsreaktionen in saurer Losung) unter Bildung u. a. von 2-Furfural, 2-Hydroxymethyl-5-furfural (HMF) beobachtet. Die Monoterpene erfahren wahrend der Alterung des Weines z. T. betrachtliche Veranderungen. Die Gehalte der Monoterpenalkohole Linalool, Geraniol und Citronellol nehmen ab, die Gehalte der vier isomeren Linalooloxide sowie von Neroloxid, Hotrienol, Hydroxylinalool und Hydroxycitronellol nehmen zu. Ferner wird die Bildung von 2,6,6-Trimethyl-2-vinyl-tetrahydropyran, von 2,2-Dimethyl-5-(1-methylpropenyl)-tetrahydrofuran, von cis-1,8-Terpin sowie

Journal ArticleDOI
TL;DR: The Kallithea intrusive complex on Samos forms part of the Miocene granitoid province of the central Aegean as mentioned in this paper, and the most spectacular feature of the composite dikes are net-veined parts in which spherical (pillow-like) to angular bodies of microdiorite are surrounded by a network of more felsic rocks of varying compositions.
Abstract: The Kallithea intrusive complex on Samos forms part of the Miocene granitoid province of the central Aegean. The complex consists of numerous composite dikes consisting of different I-type diorites, monzodiorites, (quartz) monzonites, granodiorites, and granites, as well as rare pegmatites. Within individual dikes the different rock types display various structural relationships to each other, most of which indicate that multiple intrusion was the main process responsible for the association of different rock types. Petrographical, geochemical, and Sr isotope data prove that at least some of the different magma pulses were genetically unrelated. For others, a comagmatic relationship cannot be excluded. The most spectacular feature of the composite dikes are net-veined parts in which spherical (pillow-like) to angular bodies of microdiorite are surrounded by a network of more felsic rocks of varying compositions (monzonites, granodiorites, and monzogranites). — For the microdiorite/monzogranite pairs, a formation by unmixing due to liquid immiscibility is suggested by the following facts: (a) the presence of monzogranite ocelli within the microdiorite bodies, (b) similar compositions of those minerals present in both the basic and felsic parts, (c) the enrichment of HFS elements in the basic parts and the depletion of these elements in the acid parts, (d) similar Sr isotope initial ratios. Such an origin, however, is excluded for the other net-veined parts having felsic veins of either monzonitic or granodioritic compositions. In these pairs, the HFS elements are enriched in the acid parts, common minerals may have different compositions, and Sr isotope initial ratios are different. These net-veined parts can only be explained by the model of multiple injections whereby a felsic melt intruded into a basic magma.

Journal ArticleDOI
TL;DR: In this paper, the effect of UV-B-radiation on PSII activity of spinach chloroplasts was analyzed by measuring the integrity of the herbicide-binding protein (HBP 32), by measurement of fluorescence induction in the presence of Diuron (DCMU), and by mathematical analysis of the PSII induction curves.
Abstract: Abstract The effect of UV-B-radiation on PSII activity of spinach chloroplasts was analyzed by measuring the integrity of the herbicide-binding protein (HBP 32), by measurement of fluorescence induction in the presence of Diuron (DCMU), and by mathematical analysis of the fluorescence induction curves. It was shown that UV-B inactivates the PSII α-centers but not PSII β-centers. However, the possibility cannot be excluded that in addition the donor site of PSII near the reaction center is attacked by UV-B-radiation.

Journal ArticleDOI
TL;DR: Homogenized V/sub 3/Si crystals were irradiated with fast neutrons at conditions which result in a proportionality between the induced defect density and the neutron fluence and the resulting rise of the volume pinning force is investigated as a function of the density of the weak interacting defects.
Abstract: Homogenized ${\mathrm{V}}_{3}$Si crystals were irradiated with fast neutrons at conditions which result in a proportionality between the induced defect density and the neutron fluence. The critical current density is corrected for differences in the fluence dependence of the upper critical field and of the Ginzburg-Landau parameter. The resulting rise of the volume pinning force is investigated as a function of the density of the weak interacting defects. A second power law which points to a collective interaction is observed at low defect densities and at low fields. With increasing defect density and increasing field, this quadratic dependence vanishes abruptly and an almost linear relation dominates. The exponent of this first power law decreases continuously with further increase of field or defect density. These observations are compared with the collective pinning theory.