Showing papers by "Technical University of Berlin published in 1983"
TL;DR: In this article, the binding energy of an n−type and Zn doped p−type Gax In1−xAs /InP (0.44
Abstract: Optical, crystallographic, and transport properties of nominally undoped n‐type and Zn doped p‐type Gax In1−xAs /InP (0.44
314 citations
254 citations
TL;DR: It is shown by pure counting arguments that BPP is contained in ΣP2, the second level of the hierarchy of the polynomial hierarchy of Meyer and Stockmeyer.
243 citations
TL;DR: The capacity factors of eight n-alkylbenzenes and eleven reference substances used in the OECD Chemicals Testing Programme were determined using reversed phase high-performance liquid chromatography (RP-18) at different compositions of the mobile phase (methanol) water as discussed by the authors.
132 citations
TL;DR: This chapter distinguishes two camps, one that points to the deficiency and one that argues for the efficiency of human judgment and decision, which are pessimistic and optimists, which claim that judgement and decision are highly efficient and functional even in complex situations.
Abstract: Publisher Summary Rationality is not a genuine term of scientific psychology but rather a concept of philosophy and economics. The most common and most relevant definition says that an action is rational if it is in line with the values and beliefs of the individual concerned; or more precisely, if it is logical or consistent as stated in a set of axioms. This definition specifies rational behavior normatively. Empirical research can study whether actual human behavior is rational in the sense that it obeys the norm. This chapter distinguishes two camps, one that points to the deficiency and one that argues for the efficiency of human judgment and decision. The members of the first camp—pessimists—claim that judgment and decision making under uncertainty often show systematic and serious errors because of in-built characteristics of the human cognitive system. The optimists of the other camp claim that judgment and decision are highly efficient and functional even in complex situations.
115 citations
TL;DR: A necessary and sufficient condition for stability is given from which generalizations of recent results by Gear et al. and by Zlatev can be obtained as special cases.
Abstract: This paper is concerned with the stability of multistep methods for ordinary initial-value problems on grids with variable mesh-sizes. A necessary and sufficient condition for stability is given from which generalizations of recent results by Gear et al. and by Zlatev can be obtained as special cases. As an application the stability of the variable BDF-formulas is treated.
104 citations
TL;DR: The complex projective plane (RP 2) as mentioned in this paper is a triangulation of the 2-sphere of the M6bius band with only six vertices, where each vertex has two distinct vertices and no two vertices determine more than one edge, and at most two triangles come together at every edge.
Abstract: In the early days of topology, most of the objects of interest were defined in terms of triangulations, describing a topological space as a union of finitely many vertices, edges, triangles, and higher dimensional simplexes identified in certain ways along their boundaries. A triangulation with a relatively small number of simplexes, symmetrically placed, could make computations easier and suggest new properties of the object itself. Although subsequent approaches to algebraic topology have stressed other ways of defining properties of topological spaces, the discovery of a new particularly nice triangulation of an important space can once again bring out relationships that lead to new insights in different branches of mathematics. In this article we describe such a triangulation for one of the most significant objects in topology, the complex projective plane. In a triangulation each edge has two distinct vertices and no two vertices determine more than one edge so the minimum number of vertices in a triangulation of a circle is three. In a triangulation of a surface or surface-with-boundary, each triangle has three distinct vertices and no three vertices determine more than one triangle. Moreover, at most two triangles come together at every edge. Since a cylinder has two edge curves a minimal triangulation requires at least six vertices and we can present a triangulation with precisely six vertices. On the other hand, it is possible to give a triangulation of the M6bius band with only five vertices (Figure 1, on next page) so in a sense the twist in the band makes it possible to triangulate using fewer vertices than in the case of the untwisted cylindrical band. The boundary of the M6bius band is a pentagon and every vertex is connected to every other vertex. By adding a cone over the pentagon from a sixth point we obtain a surface without boundary called the real projective plane with six vertices, fifteen edges (connecting all distinct pairs of vertices) and ten triangles. We denote this special triangulation by RP 2. It can be described by taking the icosahedral triangulation of the 2-sphere and then identifying opposite vertices, edges and faces. This triangulation RP 2 has numerous special properties. Although it is not possible to construct any nonself-intersecting real projective plane in ordinary Euclidean 3-space, we can construct a one-to-one mapping of RP 2 into Euclidean 4-space by first building a
100 citations
01 Dec 1983
TL;DR: In this article, the dual fluorescence in polar solvents of 9,9′-bianthryl (BA) and of the electronically perturbed BA-derivatives 10-chloro-BA (BACl), BA-10-carboxaldehyde (BAA) and N-(9-anthryl)-carbazole (C9A) as well as of N-(4-cyanophenyl)-carazoles (CBN) was analyzed and interpreted in terms of a simplified microstructural solvent interaction model.
Abstract: The dual fluorescence in polar solvents of 9,9′-bianthryl (BA) and of the electronically perturbed BA-derivatives 10-chloro-BA (BACl), BA-10-carboxaldehyde (BAA) and N-(9-anthryl)-carbazole (C9A) as well as of N-(4-cyanophenyl)-carbazole (CBN) is analysed and interpreted in terms of a simplified microstructural solvent interaction model. Dipole moments μT relative to μT (CBN) of the fluorescent charge transfer state have been derived from the solvatochromic band shifts in nitrile and alcohol homologous solvent series and are similar for BA, BACl and C9A. This implies that the charge transfer in the excited state occurs to a maximum degree even in the symmetric molecule BA. – QCFF/PI-potential energy curves have been calculated and are used to discuss these findings. BAA fluoresces in alcohols only, μT-compared to the other compounds studied being somewhat smaller probably because of specific H-bond interactions with the solvent. – Using relative fluorescence quantum yields and energetic considerations the dependence of the excited states equilibrium on both solvent polarity and solute perturbation is discussed.
97 citations
TL;DR: This paper found that the vast majority of these pauses are psychological; they are determined by syntax, punctuation, rhetorical and expressive emphasis, poetic format, and stylistic pecularities.
Abstract: The historical provenance of a minimum cut-off point (of about 0.25 sec) for pauses in temporal analyses of speech production is associated with Goldman-Eisler's usage. Her rationale was the predominance of articulatory pauses at lengths shorter than 0.25 sec. Both phonotactic facts and empirical analysis of several corpora of readings disconfirm this predominance with respect to pauses 0.13-0.25 sec in length. The vast majority of these pauses are found to be psychological; they are determined by syntax, punctuation, rhetorical and expressive emphasis, poetic format, and stylistic pecularities.
91 citations
01 Jun 1983-Metallurgical and Materials Transactions B-process Metallurgy and Materials Processing Science
TL;DR: A process for preparing Al-alloy castings containing dispersions of zircon particles is described in this article, where composites were prepared by stirring Zircon particle (40 to 200 µm size) in commercially pure Al (99.5 pct)* and Al-11.8 pct Si melts and subsequently casting these melts in permanent molds.
Abstract: A process for preparing Al-alloy castings containing dispersions of zircon particles is described. Composites were prepared by stirring zircon particles (40 to 200 µm size) in commercially pure Al (99.5 pct)* and Al-11.8 pct Si melts and subsequently casting these melts in permanent molds. It was found to be necessary to alloy the above two melts with 3 pct Mg to disperse substantial amounts of zircon particles (25 to 30 pct). Further, it was possible to disperse up to 60 wt pct zircon by adding up to 5 pct Mg; however, the melts containing above 30 wt pct zircon showed insufficient fluidity for gravity diecasting and had to be pressure diecast. Microstructural studies of cast composites indicated the presence of a reaction zone at the periphery of zircon particles, and electron probe microanalysis showed concentrations of Mg and Si at the particle-matrix interface. Hardness, abrasive wear resistance, elastic modulus, 0.2 pct proof stress, and tensile strength of cast Al-3 pct Mg alloy were found to improve with the dispersions of zircon particles. Scanning electron micrographs of abraded and fractured surfaces did not show any evidence of particle pull-outs or voids at the particle matrix interface, indicating strong continuous bonding.
86 citations
TL;DR: In this article, Schistostephium species were used to identify 43 new compounds, including isocomene, bisabolene, eudesmane and nerolidol derivatives, and a prostaglandin-like acid.
TL;DR: In this article, the results of breakdown voltage investigations of planar devices with field limiting rings are described and the optimal ring spacings for devices with more than one field ring and the influence of surface charges on the blocking capability are extensively studied.
Abstract: The results of breakdown voltage investigations of planar devices with field limiting rings are described. The two-dimensional Poisson equation is solved using the finite difference method. The question of the optimal ring spacings for devices with more than one field ring and the influence of surface charges on the blocking capability are extensively studied. The influence of the following device parameters is discussed: ring spacing, ring width, doping gradient and surface charge density. An analytical model for simplified calculations showing the principal characteristics of field ring devices is presented. Furthermore some experimental results of EBIC measurements are shown.
TL;DR: In this article, the hydrogarnet substitution in pyrope may contribute to water contents in the mantle, and the water contents due to (HO)44− clusters are estimated near 0.05 wt.% H2O from spectroscopic data.
TL;DR: In this paper, 27 rock and seven mineral samples of Ta-bearing and barren pegmatites from four localities in southwestern and one locality in central Nigeria have been investigated, indicating an older crustal history of the sample material; there are no differences for barren and mineralized pegmatite, albitization does not affect the initial Sr ratios.
TL;DR: The present paper gives the generalization of Chow’s result (by means of a different proof) to the case of arbitrarily many exponential servers.
Abstract: In [1] Chow obtained the steady-state distribution of the cycle time of a customer in a closed tandem queue composed of two exponential FIFO servers and populated by an arbitrary fixed number of customers. The present paper gives the generalization of Chow’s result (by means of a different proof) to the case of arbitrarily many exponential servers.
TL;DR: The formal theory in this paper is restricted to the basic algebraic case where only equations are allowed in the parameter declaration and parameter passing is given by specification morphisms, but the main ideas of a corresponding theory with requirements where the authors allow different kinds of restrictions in the parameters declaration are given.
TL;DR: In this article, the blue phases of two cholesteric systems were studied under the influence of an electric field, and the wavelength of maximum absorption due to the selective reflection of circularly polarized light of both blue phase I (BP I) and blue phase II (BP II) turns out to be shifted to longer wavelengths with increasing electric field.
Abstract: The blue phases of two cholesteric systems are studied under the influence of an electric field The wavelength of maximum absorption due to the selective reflection of circularly polarized light of both blue phase I (BP I) and blue phase II (BP II) turns out to be shifted to longer wavelengths with increasing electric field In addition to that, a phase transition from BP II to BP I is observed for one of the systems used Under favorable conditions, brilliant color changes from blue to red are observed in the reflected light
23 May 1983
TL;DR: Finnish, French, German, and Spanish were examined under the hypothesis that they are characterized by commonalities in the use of time as mentioned in this paper, based on the same speech type, story-telling elicited by pictorial materials.
Abstract: Finnish, French, German, and Spanish) were examined under the hypothesis that they are characterized by commonalities in the use of time Each study was based on the same speech type, story telling elicited by pictorial materials The temporal measures were speech and articulation rates, pause duration, phrase length, and percentage of pause time/total time The hypothesis was confirmed except for studies carried out with identifiably variant methodologies Further support for the hypothesis was found by contrasting the use of time characteristic of interviewees’ speech Temporal phenomena have come to assume an important role in research on speech production as the relationship of various independent variables to these phenomena has gradually become known Among the independent variables, age (eg, Starkweather, 1980; Kowal, O’Connell and Sabin, 1975) and foreign language proficiency (eg, Wiese, 1983) are perhaps the most obvious Differential use of time has typically been interpreted in terms of the various cognitive demands involved in speech production Although speech type has clearly been acknowledged to be an important independent variable, it is not as yet clear how narrowly a speech type must be operationally defined in order to yield temporal data that can be replicated As long as speech type categories as broad as reading and spontaneous speech are used, the purpose of replicability and predictability will not be attained On the other hand, if the speech type category yields replicable data only for a trivially narrow subset of experimental situations, again it becomes a useless category It is the thesis of the
TL;DR: The mikrofazielle und palaontologische untersuchung der Karbonate der Kossener Schichten (Raum Salzburg-Tirol) as discussed by the authors showed, das diese Sedimente in geschutzten Intraplattform-Beckenbereichen abgelagert wurden.
Abstract: Die mikrofazielle und palaontologische Untersuchung der Karbonate der Kossener Schichten (Raum Salzburg-Tirol) zeigt, das diese Sedimente in geschutzten Intraplattform-Beckenbereichen abgelagert wurden. In alle Profilen konnen drei ubergeordneteFazieseinheiten unterschieden werden: I. Tonmergel/Kalk-Folge; II. Korallenkalke; III. Kalkbank/Mergel-Folge; sie setzen sich aus 14 Mikrofaziestypen zusammen, deren vertikale Abfolge (beim Vergleich verschiedener Profile) diachron verlauft. Gleiches gilt auch fur die ubergeordneten Fazieseinheiten, die innerhalb eines Profiles mehrfach altenierend vorkommen, wobei durch Fazieseinheit III eine Absenkung des Ablagerungsgebietes dokumentiert wird. Die sieben Mikrofaziestypen derTonmergel/Kalk-Folge (I) entsprechen Flachwasserkarbonaten, die in geschutzten oder brandungsexponierten Bereichen entstanden. Daneben beeinflusten Salinitat und episodische, hoherenergetische Events die Verteilung der Organismen und Mikrofaziestypen: Algal laminated Bindstones (I/1), Peloidmikrite (I/2), Mudstones (I/3), Lumachelle (I/4), Bioclastic Grainstones (I/5), Onkoid Fazies (I/6), Oolithic Grainstones (I/7). Bei denKorallenkalken (Fazies-Einheit II) sind zwei, genetisch verschiedene Typen zu unterscheiden: Der “Flach-marine Korallenkalk” entstand im Bewegtwasser; Fauna und Flora lassen Anklange an die Rhatriffkalke bzw. Dachsteinriffkalke erkennen. Der “Tiefermarine Korallenkalk” entstand unterhalb der photischen Zone, jedoch noch im Einflusbereich episodischer Sturmflutsedimentation. Die vier Mikrofaziestypen (Riffdetritus-Schlamm-Fazies (II/1), Biostrom-Fazies (II/2), Mud-Mound Fazies (II/3) und Coated Grain Fazies (II/4) sind teilweise nur im Aufschlus erkennbar.Fazieseinheit III ist durch monotone Kalk/Mergel-Wechsellagerungen mit Echinodermen-Detritus-Schlamm (III/1) und Detritus-Schlamm-Fazies (III/2) charakterisiert, deren artenarme Faunen keinerlei Hinweise auf flachmarine Ablagerung aufweisen. Die hochdiversen Spurenfossilien sprechen fur grosere Ablagerungstiefen. Die Funde stratigraphisch wichtigerChoristoceres-Arten beschranken sich auf die Fazieseinheit III. Palaontologie: In den flachmarinen Karbonaten kommen Korallen, Foraminiferen, Echinodermen und Mikroproblematika, seltener Schwamme, Hydrozoen und Algen vor, die im Vergleich mit den Rhatriffen eine deutlich geringere Diversitat aufweisen. Brachiopoden, Mollusken, Ophiuren und Ammoniten der Kossener Mergel sind fur fazielle und biostratigraphische Aussagen wichtig. Die Verteilung der benthonischen Foraminiferen zeigt in den Profilabfolgen charakteristische Foraminiferengesellschaften: So ist furAgathammina austroalpina, Glomospira sp. und zartschalige Nodosariiden eine Anpassung an extreme Salinitatsbedingungen feststellbar.Agathammina austroalpina kommt daneben auch als einzige Foraminifere innerhalb der Tempestit-Lumachellen vor.Aulotortus gaschei ist fur die Onkoidkalke typisch und kommt als einzige Foraminifere in den Oolithen mit radialfibrosen Ooiden vor. In der Fazieseinheit III fehlen Involutinen und Textularien, die individuenarmen Formen beschranken sich aufTetrataxis, Planiinvoluta und kleinwuchsige Miliolidschaler. Die flachmarinen Korallenkalke (II) sind durch individuenreiche Involutinen-Assoziationen gekennzeichnet. Die Foraminiferenverteilungen in den tieferen Korallenkalken ergibt ein deutliches Arten- und Individuenmaximum in der Mud-Mound Fazies. Die geringste Anzahl an Individuen wurde in der Coated-Grain-Fazies gezahlt. Die Ablagerung der Flachwasserkarbonate fand unter dem Einflus episodischer Sturmflutereignisse statt, die sich in dichtgepackten, lagigen Anhaufungen von Schalen, Detritus oder Korallen dokumentieren. Die Machtigkeiten dieser Tempestitlagen hangen von der jeweiligen Sedimentationsenergie ab, was durch verschiedene Sedimentmarken zum Ausdruck kommt. Meeresspiegelschwankungen stellen die Ursache fur das Ende der tieferen Korallenkalkentwicklung dar. Dies ist aus den vados/marinen bzw. vadosen Losungs- und Zementationsvorgangen ersichtlich, die eine zeitweilige subaerische Exposition wahrscheinlich erscheinen lassen. Die grobspatigen Blockzemente entstanden unter Suswasser/phreatischen Bedingungen; dies wird auch durch die Mn-Anreicherungen und Sr-Abreicherungen in diesen Zementen bestatigt. Als weitere fazieskritische Parameter konnen Sourenelemente (Fe, Mn, Mg, Sr) und der unlosliche Ruckstand betrachtet werden, deren Verteilungen mit Hilfe von Cluster- und Faktorenanalysen untersucht wurden. Die primarmineralogische Zusammensetzung und diagenetische Stoffverschiebungen sind fur die Variabilitat dieser Parameter verantwortlich. Die Sr- und Mn-Verteilungen innerhalb der einzelnen Profile zeigen Unterschiede, die beim Sr auf verschieden starke diagenetische Abreicherungen zuruckzufuhren sind. Die Unterschiede in den Mn-Gehalten sind durch die unterschiedlichen Blockzementvolumina und durch den primar unterschiedlichen Chemismus der phreatischen Porenwasser bedingt, die zur Blockzementbildung beitrugen.
TL;DR: In this article, the linearity error is less than ± 1% within a rotation range of 300 to 200,000/h for direct rotation-rate detection with digital processing.
Abstract: By using digital processing, the dynamic range of gyros with direct rotation-rate detection is no longer restricted. The linearity error is less than ±1% within a rotation range of 300 to 200000/h.
TL;DR: In this paper, the shape memory effects of alloys are described in three dimensions by means of an extended classical theory of plasticity, and two temperature-dependent yield criteria are used which respond under different conditions.
TL;DR: The protein chemical determination proves that for the large subunit of ribulosebisphosphate carboxylase from N. tabacum there exist at least two (if not more) slightly different genes.
01 Jan 1983
TL;DR: The rheological properties of mould suspensions were investigated to find out the effect of mycelial morphology on the apparent viscosity with two different growth forms, filamentous and pelleted forms of Absidia corymbifera by using a helical ribbon impeller system.
Abstract: The rheological properties of mould suspensions were investigated to find out the effect of mycelial morphology on the apparent viscosity with two different growth forms, filamentous and pelleted forms of Absidia corymbifera. By using a helical ribbon impeller system, the rheological properties could be satisfactorily measured. The experimental data obtained with the filamentous mycelial suspensions showed a marked deviation from Newtonian behaviour and were correlated by a pseudoplastic model. With the pelleted mycelial suspensions, the tendency of Newtonian behaviour was observed. However, at the higher mycelial concentration (>28 g/l) its rheological behaviour was changed toward a pseudoplastic. The parameters in the pseudoplastic model were compared between these two different morphologies. The consistency indices were correlated with the mycelial dry weight by a simple power law equation and the power law constants found were 2.3 for the filamentous mycelial suspension and 11.3 for the pelleted one.
01 Sep 1983
TL;DR: Pachysolen tannophilus IfGB 0101, is able to grow aerobically on xylose, glucose and fructose, and the significance of xylitol formation seems to be mainly that of an electron sink of the phosphogluconate pathway.
Abstract: Pachysolen tannophilus IfGB 0101, is able to grow aerobically on xylose, glucose and fructose. Galactose too is assimilated after long adaption times. In the complete absence of oxygen, xylose is fermented, forming mainly xylitol, lower amounts of ethanol and CO2. According to the mass balance, it may be concluded that the pentose phosphate enzymes together with the oxidative phosphogluconate way are in action simultaneously. At semi-aerobic conditions (0.45 l air per liter, per hour) ethanol production is somewhat increased but no aeration conditions could as yet be found at which ethanol was the main fermentation product. The significance of xylitol formation seems to be mainly that of an electron sink of the phosphogluconate pathway.
TL;DR: In this article, the Gasch and Drechsler method is extended to multibearing rotors with initial shaft bow and the results show that flexible shafts mounted in ball bearings can be balanced with very good results.
TL;DR: In this article, it was shown that the course of the River Niger is structurally controlled by sets of linear faults, trending NW-SE, before its joining up with the River Benue at Lokoja.
Proceedings Article•
08 Aug 1983TL;DR: This paper presents a model-driven method for machine learning of inference rules, which involves both: ' learning by induction' and 'learning by being told'.
Abstract: This paper presents a model-driven method for machine learning of inference rules, which involves both: 'learning by induction' and 'learning by being told'. By the use of higher concepts (like transitivity and conversity) attributes of and relations among two-place predicates are discovered by induction. This new knowledge is represented as metafacts which can be transformed into inference rules if needed. The relations among meta facts are expressed as meta rules. The higher concept of support sets correspond to the domains for which meta facts are true. The process of restructuring support sets in order to resolve contradictions (and to make inference rules more precise) is discussed.
TL;DR: In this paper, a YAG-laser beam partially absorbed in a Si-crystal, produces refractive index changes and free carrier production and thermal index changes are discussed as mechanisms.
TL;DR: In this paper, the reaction of carbon monoxide with nickel field emitter surfaces is investigated by means of pulsed field desorption mass spectrometry at pressures of 10−6 to 3 × 10−2 Pa and temperatures between 270 and 420 K.