Showing papers by "University of Paderborn published in 1982"
TL;DR: In this paper, the authors investigate whether emotions causing impulse buying can be identified empirically by interview data and observation of the mimical expression of buyers and non-buyers, and the results support the validity of the techniques employed.
444 citations
TL;DR: In this article, two nonlocal recursion operators are given, which yield explicit formulas for infinite hierarchies of symmetry generators and conservation laws for the two-dimensional Korteweg-de Vries equation.
117 citations
TL;DR: In this article, the occurrence of tetracyclic triterpanes in petroleum was reported, which presumably derive from pentacy-clic hopanes by ring C opening, and one C30H54 8,14-seco-hopane has been effected by means of comparison with a mixture of synthetic isomeric compounds.
55 citations
TL;DR: In this article, high purity protactinium was studied by X-ray diffraction in a diamond anvil cell up to 53 GPa and the body-centred tetragonal structure was retained through the whole pressure range.
35 citations
01 Jun 1982
TL;DR: In this article, a standard-apparatur fur Warmeubergangsmessungen beim Sieden entwickelt wurde with verschiedenen Kaltemitteln in einem weiten Bereich der Warmestromdichte und des Siededrucks erprobt.
Abstract: Messungen des Warmeubergangs beim Blasensieden, die in verschiedenen Laboratorien durchgefuhrt wurden, weisen oft grose Unterschiede auf, auch fur den gleichen Stoff und gleiche Versuchsbedingungen. Um den Einflus apparativer und versuchstechnischer Vorgaben auf das Mesergebnis zu vermindern, wurde eine Standard-Apparatur fur Warmeubergangsmessungen beim Sieden entwickelt. Apparatur und Mesverfahren wurden mit verschiedenen Kaltemitteln in einem weiten Bereich der Warmestromdichte und des Siededrucks erprobt. Im allgemeinen ist die Unsicherheit der Meswerte des Warmeubergangskoeffizienten kleiner als funf Prozent; grosere Fehler ergeben sich nur bei sehr hohen normierten Siededrucken und niedrigen Warmestromdichten.
29 citations
TL;DR: An algorithm is presented to solve GAP deterministically in space log S ( n )× logn, which results in a log space complete family of problems for NSPACE and DSPACE.
25 citations
TL;DR: In this article, a unified field theory is developed on the basis of the five-dimensional vacuum equations in the projective theory of relativity, which represents the intrinsic particle properties, which are the rest mass, or the energy in case of photons and neutrinos, the charge and the spin by integrals of the field distribution extended over spacelike hypersurfaces.
Abstract: A unified field theory is developed on the basis of the five-dimensional vacuum equations ${R}_{\ensuremath{\mu}\ensuremath{
u}}=0$ in the projective theory of relativity. The four-dimensional field equations following from ${R}_{\ensuremath{\mu}\ensuremath{
u}}=0$ by projection are a generalized Einstein-Maxwell theory, for which the generalization is given by a scalar field. The particle concept based on these equations represents the intrinsic particle properties, which are the rest mass, or the energy in case of photons and neutrinos, the charge and the spin by integrals of the field distribution extended over spacelike hypersurfaces. The energy concept is based on M\o{}ller's energy-momentum complex. M\o{}ller's argument against his energy-momentum complex is discussed and refuted. The spin concept is derived from the axial symmetry of the field distribution. In the spherically symmetric static case the solutions of the field equations are given and investigated for their particle properties. It is shown that one and only one type of solution yields a good approach to the distribution of charge and rest mass in the proton. However, none of the spherically symmetric solutions represents the electron.
24 citations
TL;DR: In this article, it was shown that a class of dissipative dynamical systems with limit-cycle and chaotic behavior can be derived from a Lagrange function, and a particular system is investigated numerically.
Abstract: It is shown that a class of dissipative dynamical systems with limit-cycle and chaotic behavior can be derived from a Lagrange function. A particular system is investigated numerically.
24 citations
TL;DR: In this paper, the authors studied linear and nonlinear diffusion equations with the help of Lie and Lie-Backlund transformation groups and showed that the Lie transformation groups can be used to solve nonlinear and linear diffusion equations.
Abstract: Linear and nonlinear diffusion equations are studied with the help of Lie and Lie-Backlund transformation groups.
23 citations
01 Jan 1982
21 citations
TL;DR: In this article, the bulk viscosity of two cholesteric mixed systems cholesteryl nonanoate/cholesteryl chloride and CB 15/ZLI 1612 has been measured using Ubbelohde capillary viscometers.
Abstract: The bulk viscosity of two cholesteric mixed systems cholesteryl nonanoate/cholesteryl chloride and CB 15/ZLI 1612 has been measured using Ubbelohde capillary viscometers. A viscosity maximum close below the clearing point only has been observed in such mixtures exhibiting blue phases (BP). Cholesteric systems with larger pitches in which no BPs exist show a nematic-like capillary flow behaviour.
TL;DR: In this article, the α-anomer of ara-7-deazaguanosine (2) has been prepared via phase-transfer glycosylation of 4-methoxy-2-methylthio-7H-pyrrolo[2,3-d]pyrimidine (3) with 2,3,5-tri-O-benzyl-1-bromoarabinofuranose (5a/5b).
TL;DR: In this article, the pitch dependence of cholesteric blue phase stability was investigated in a compensable mixed system of CHN/chloride, and two critical pitches above which no blue phase exists were found depending on the structure of the liquid crystal.
TL;DR: It can be concluded, that immobilization of adenosine deaminase on cyanogen-bromide-activated dextran took place via these lysyl residues, and that the matrix of polymer-linked adenoine deamination is degradable by a bacterial endodextranase.
Abstract: Dextran-linked adenosine deaminase (EC 3.5.4.4) has been prepared. The polymer-linked enzyme possesses an optimal cnzymatic activity of 27 units/mg immobilized protein (non-bound enzyme: 200 units/mg protein). Support-bound adenosine deaminase (4.5 pg protein/mg dextran) shows an enhanced heat stability, a moderately -increased Km and a decreased V value compared to those of the free enzyme. The pH dependences of V and PKm values of dextran-linked adenosine deaminase show only two inflection points compared to three for the free enzyme, which are equivalent to the PK values of the enzyme. Since the missing third inflection point (pH 9.8) can be assigned to the pK value of the ɛ-amino group of lysyl residues, it can be concluded, that immobilization of adenosine deaminase on cyanogen-bromide-activated dextran took place via these lysyl residues. The remaining pK values found from tlie other inflection points are moderately shifted owing to the altered secondary structure. From the temperature dependence of the enzymatic activity, a 40% decrease of the activation energy of the support-bound enzyme was found, indicating diffusion controlled deamination. The immobilization of adenosine deaminase results in a fluorescence quenching of 80%, without shifting the ultraviolet maximum of the emission spectrum. As already shown for unmodified dextran, the matrix of polymer-linked adenosinc deamniase is degradable by a bacterial endodextranase (EC 3.2.1.11).
TL;DR: In this article, the α-anomer of 7-deazaguanosine has been synthesized using the pyrrolo[2,3-d]pyrimidine derivate.
TL;DR: There exists a 2-dimensional 6-state 9-neighbor deterministic asynchronous cell space (alternatively, a nondeterministic synchronous cell space) capable of simulating the safe behavior of any Petri net.
Abstract: There exists a 2-dimensional 6-state 9-neighbor deterministic asynchronous cell space (alternatively, a nondeterministic synchronous cell space) capable of simulating the safe behavior of any Petri net.
TL;DR: In this article, a cyclotubercidin isosteric analogue of the antivirus active acyclonucleoside has been synthesized using benzyltriethylammonium chloride as a phase transfer catalyst.
TL;DR: In this paper, a phase-transfer glycosylation of pyrrolo[2,3-d]pyrimidine with 2,3,5-tri-O-benzyl-1-bromo-D-arabinofuranose in aqueous NaOH/CH2Cl2 in the presence of molar amounts of tetrabutylammonium hydrogen sulfate a byproduct of the aglycon was observed.
TL;DR: In this paper, the N-7-methyl derivatives of 7-deazahypoxanthine were synthesized by phase-transfer methylation of 4-methoxy-2-methylthio-7H-pyrrolo[2,3-d] pyridine with N-(methyl)thiourea via the pyrimidine 4a which after cyclisation to 5a was desulfurised to 3.
TL;DR: In this article, a theory of the electric conductivity in homogeneous and stationary binary electrolytes is developed which is valid up to concentrations c ≈ 1 mol/l. The results are in a very good agreement with experimental data.
Abstract: A theory of the electric conductivity in homogeneous and stationary binary electrolytes is developed which is valid up to concentrations c ≈ 1 mol/l. It is based on the stochastic Liouville equation, the linear superposition approximation in the cluster expansion of the 3-particle distribution functions and the hydrodynamical approximation in the expansion of the 2-particle distribution functions by their moments in momentum space. The limiting law in dilute electrolytes is calculated analytically. For hydrous electrolytes the conductivity is calculated numerically up to concentrations c ≈ 1 mol/l. The results are in a very good agreement with experimental data.
TL;DR: In this article, the synthesis of 2,3-Dihydro-1H-pyrazolo[1,2-a]-pyrazol-4-ium-tosylaten is described.
TL;DR: In this article, the behaviour of the dynamical system x = y, y = −x−μ sin y is studied in the context of electrical circuit theory, where the authors focus on the behavior of the system x and y.
Abstract: This note is concerned with the behaviour of the dynamical system x = y, y = −x−μ sin y which is important in electrical circuit theory.
TL;DR: In this article, a debenzylation of the sugar moiety of pyrrolo[2,3-d]pyrimidine nucleosides without affecting methoxy or methylthio substituents of the chromophore has been accomplished by the action of boron trichloride/dichloromethane at 78°C.
TL;DR: In this paper, a finite pitch of the cholesteric helix at the phase transition point Ch/SA was shown to change into an infinite pitch at a given point on the phase equilibrium line.
Abstract: Experimental evidence is given, for the first time, for a finite pitch of the cholesteric helix at the phase transition point cholesteric/smectic A (Ch/SA). This finite pitch changes into an infinite one at a given point on the phase equilibrium line Ch/SA. Therefore this point is called the pitch infinity point (PIP). With increasing n-alkyl chain length of the investigated cholesteryl n-alkanoates the pressure coordinate of the PIP is shifted to higher values up to a chain length of 13 C atoms. For the alkanoates with 13,15 and 17 C atoms the same PIP pressure of about 1000 bars was determined. The Ch/SA phase equilibrium line of the cholesteryl esters could at best be followed up to 2600 bars. The respective transition enthalpies were measured at normal pressure and the corresponding changes in volume calculated by means of the Clausius-Clapeyron equation.
TL;DR: In this article, the Krawtchouk series representation of maximally flat FIR lowpass filters is used to derive a class of monotone bandpass filters and exact design formulas are given.
Abstract: Starting with the Krawtchouk series representation of maximally flat FIR lowpass filters, a class of monotone bandpass filters is derived and exact design formulas are given.
TL;DR: It is concluded that no diffusion control of the enzymatic reaction results from the binding of the nucleoside acetals to dextran T80, and the length of the polysaccharide chain does not interfere either with the complex formation or with the catalytic activity of the modified substrate.
Abstract: Dextran-bound adenosine, inosine, and nebularine have been prepared by carbodiimide coupling of their 2′,3′-O-(4-carboxyethyl-1-methylbutylidene) cyclic acetal derivatives to 6-aminohexyldextran or 12-aminodode-canyldextran. The latter polymers were prepared by cyanogen-bromide activation of dextran T80 followed by reaction with 1,6-diaminohexane or 1,12-diaminododecane. A high CNBr concentration leads to high-molecular-weight material, probably due to cross-linking, accompanied by a decrease in the digestion velocity using endo-dextranase from Penicillium species (EC 3.2.1.11).
The dextran-bound nucleosides, as well as the nucleoside 2′,3′-O-(4-ethoxycarbonyl-1-methylbutylidene) acetal derivatives, were tested as substrates and inhibitors for adenosine deaminase. The Km, of the adenosine acetal ester is identical to that of adenosine which shows that acetalation does not hinder complex formation. Since the maximum velocity of deamination is decreased fourfold, the modified substrate does not fit as well as the nucleoside. The polymer-bound acetals show a 3–8-fold increase of Km, or Ki and unchanged V compared to the corresponding acetals while dextranase digestion of the support does not alter the kinetic data. This indicates that the length of the polysaccharide chain does not interfere either with the complex formation or with the catalytic activity of the modified substrate. Since the activation energies of the deamination reactions of adenosine, its acetal ester, and dextran-linked adenosine are all similar (29.8–32.3 kJ mol−1) it is concluded that no diffusion control of the enzymatic reaction results from the binding of the nucleoside acetals to dextran T80.
TL;DR: In this article, the authors formulate a thermodynamic field theory in discontinuous media from which they can deduce all relevant interfacial relations, and give a rigorous discussion of the entropy inequality and the constitutive equations.
TL;DR: In this article, two adenosine molecules are connected via their ribose moieties by transacetalation with 2,2,5,5-tetraethoxyhexane, yielding diastereoisomeric bisopropylidene adenosines with S,S- or R,Sconfigurated (1b) acetal carbons.