Showing papers by "Wrocław University of Technology published in 1980"
TL;DR: In this paper, it was found that alkenylhydroquinone ethers can be demethylated with argentic oxide or ceric ammonium nitrate in the presence of 2,4,6-pyridinetricarboxylic acid as a catalyst and afforded ubiquinone-2, menaquinone-1 and their analogs in yields of 53 to 89%.
121 citations
TL;DR: In this paper, the energies of the low lying electronic states of p -cyano-N,N-dimethylaniline (CDMA) in its planar and in 90° twisted conformation have been calculated using the modified INDO method.
92 citations
TL;DR: In this paper, a method was presented of evaluating the kinetic parameters for the ignition reaction of coal based on the Semenov's thermal ignition theory adopted to coal particle ignition, which was made by comparing the measured induction periods for the coal particles with those calculated numerically.
69 citations
TL;DR: In this article, the results of a multistage separation with fresh and reused liquid surfactant membrane was also applied to copper, cobalt and nickel mixed aqueous solution, and the results showed that the process can be strongly competitive with liquid-liquid extraction, in particular in applications to the hydrometallurgical processing of low grade raw materials.
51 citations
TL;DR: In this paper, the formation of microgel-like particles even at the very beginning of polymerization, as a consequence of predominant cyclization, has been studied in pregel chain polymerization of ethylene dimethacrylate.
50 citations
TL;DR: In this paper, the effect of the chemical structure of porous copolymers formed from actrylonitrile and divinylbenzene (DVB) containing various weight fractions of polar units (12, 19, 26, 40 and 58% AN) on their physicochemical and sorption properties has been examined.
35 citations
TL;DR: In this article, the enthalpies and temperature of fusion and solid transitions and the heat capacity curves for naphthalene (NAP), anthracene, carbazole, 1,3,5-trinitrobenzene (TNB) and charge transfer complexes of TNB with these donors have been determined by using a Perkin-Elmer DSC-1B scanning calorimeter in the temperature range 180 K to just below the melting point.
35 citations
TL;DR: The consistency of the Parzen kernel-type as well as recursive kernel estimates of a regression function is shown and the problem of selecting asymptotically optimal kernels is discussed.
35 citations
32 citations
TL;DR: Human liver fructose-1,6-bisphosphatase has been purified 1200-fold using a heat treatment step followed by absorption on phosphocellulose at pH 8 and specific elution with buffer containing the substrate and allosteric effector.
30 citations
TL;DR: Weak base anion exchange membranes with diethylamine groups have been prepared on the basis of low-density polyethylene modified by styrene and divinylbenzene in the presence of iso-octane or toluene as inert diluents.
Abstract: Weak base anion exchange membranes with diethylamine groups have been prepared on the basis of low-density polyethylene modified by styrene and divinylbenzene in the presence of iso-octane or toluene as inert diluents. The effect of the kind and amount of the inert diluent used during interpolymerization on properties of thus obtained membranes has been studied. The membranes were found to have similar anion exchange capacity, but their diffusion propeties toward strong mineral acids have been found to depend on the inhomogeneity of styrene-divinylbenzene copolymer gel as well as the mode of its distribution in the amorphous phase of polyethylene.
Schwach basische Membranen mit Diethylamingruppen wurden auf der Grundlage von Hochdruckpolyethylen, modifiziert mit Styrol und Divinylbenzol, in Gegenwart von Isooktan order Toluol erhalten. Der Einflus der Art und der Menge von inertem Losungsmittel in dem Interpolymerisationsprozes auf die Eigenschaften solcher Membranen wurde diskutiert. Es wurde festgestellt, das die Membranen ahnliche Anionenaustauschkapazitaten haben, das aber ihre Diffusionseigenschaften gegen starke Mineralsauren von der Inhomogenitat des Styrol-Divinylbenzol-Copolymergels und der Art seiner Verteilung in der amorphen Polyethylenphase abhangen.
TL;DR: In this article, a transient analysis of the electron beam induced current in a semiconductor diode structure was performed when the beam in a SEM is cut off, and the influence of the layer thickness on current vs time characteristics has been shown.
Abstract: The paper presents a transient analysis of the Electron Beam Induced Current in a semiconductor diode structure, when the electron beam in a SEM is cut off. A thin layer (the thickness of the layer is comparable to or less than the minority carrier diffusion length) with a p - n junction parallel to the surface has been considered. The influence of the layer thickness on current vs time characteristics has been shown. Calculations for any value of surface recombination velocity have been made.
TL;DR: In this paper, the authors examined the absorption, fluorescence and fluorescence excitation spectra of twenty pseudoazulenes and found that seventeen of them emit S 2 → S o anomalous fluorescence, with quantum yield 10 −3 -10 −5.
TL;DR: In this paper, reactions of pyridyl-pyridinium halides with thiolpyridine and thiourea were investigated, and new dipyride sulfides were obtained by this method.
Abstract: Reactions of pyridyl-pyridinium halides with thiolpyridines and thiourea were investigated. New dipyridyl sulfides were obtained by this method.
TL;DR: In this paper, 9-Aminofluorenphosphonsauren (Morphaktine) entstehen durch addition of Diethylphosphit an 9-Imino-fluorenderivate.
Abstract: Zur Synthese von Phosphono-Analoga des Morphaktins
9-Aminofluorenphosphonsauren (Morphaktine) entstehen durch Addition von Diethylphosphit an 9-Imino-fluorenderivate. Die primar erhaltenen Ester werden zu den korrespondierenden Sauren hydrolysiert, eine Reihe der Aminophosphonsauren zerfallen unter den Bedingungen der Hydrolyse in 9-Fluorenonderivate und die entsprechenden Amine.
TL;DR: In this paper, the INDO method was used to calculate electronic charge densities in the ground and lowest excited singlet and triplet states of neutral and protonated 2,3- and 1,4-diaza derivatives of naphthalene and phenanthrene, and benzo (a) phenazine.
TL;DR: The porosity measured for two series of diluent-modified styrene copolymers (10 and 20 wt.-% of DVB) was found to depend on sample pre-treatment as discussed by the authors.
Abstract: The porosity measured for two series of diluent-modified styrene (S) — divinylbenzene (DVB) copolymers (10 and 20 wt.-% of DVB) was found to depend on sample pre-treatment. A correlation between the volume fraction of the polymer in the swollen gel and the volume fraction of octane used as diluent has been established assuming the isotropic swelling of the sample pretreated with water before porosity determination.
TL;DR: In this paper, a modified measuring system with piezoelectric generation of dynamic condenser vibrations made it possible to widen the range of measurements to the infra-red region.
TL;DR: In this paper, the properties of polyvinyl chloride (PVC) and mixtures of PVC and polyurethanes (PUs) are discussed, and it has been found that PVC modified with PUs has a lower tensile strength, but exhibits an increased impact strength.
Abstract: Some properties of poly(vinyl chloride) (PVC) and mixtures of PVC and polyurethanes (PUs) are discussed. Six different PUs of varying molar ratios of NCO/OH, and differing in the kind of glycol used as a chain extender were used as modifiers. It has been found that PVC modified with PUs has a lower tensile strength, but exhibits an increased impact strength. Moreover, it was found to have better processability and enhanced dynamic thermal stability.
Es wurden die Eigenschaften von Poly(vinylchlorid) (PVC) und Mischungen von PVC mit Polyurethanen beschrieben. Zu der Modifizierung wurden verschiedene Polyurethane mit unterschiedlichen molaren Verhaltnissen von NCO/OH und Glykole verwendet. Die PVC/Polyurethan-Mischungen weisen eine hohere Kerbschlagfestigkeit und eine geringere Zugfestigkeit als reines PVC auf. Die Verarbeitungseigenschaften sind ebenfalls besser.
TL;DR: In this paper, the condition of a continuously stirred tank (SST) was measured by platinum and bromide electrode potentials, and the potential from both electrodes was recorded simultaneously in a x-y recorder.
TL;DR: In this paper, the molar excess Gibbs free energy (GE) and excess chemical potentials were determined for {(1 − x)KReO4 + xCsReO 4}(s) at 806 K. The Knudsen-cell mass-spectrometric technique was used.
TL;DR: In this article, phase diagrams of binary systems formed by 2,4,7-trinitrofluoren-9-one (TNF) and naphthalene (N), anthracene (AN), pyrene (P), fluorene (F), dibenzothiophene (DBT) or carbazole (C) have been elaborated by differential scanning calorimetry and hot-stage microscopy.
TL;DR: In this article, the results were interpreted in terms of the formation of the binuclear species [Fe(OH)R 2 ] 2 and [Fe (OH) 2 R·HR] 2 in the organic phase.
TL;DR: In this article, 3-Nitropyridine 1-oxide and 5-methyl-3-nitropyride 1oxide are produced by oxidative demethylation using SeO 2 of 2-methyl and 2,5-dimethyl-3 -nitroparidine 1oxides.
TL;DR: In this paper, the origin of numerious OD stretchings using the isotope dilution technique was investigated using low temperature Raman spectra, and three crystallographically nonequivalent water molecules with different extent of vibrational distortion were established in the ferroelectric phase of the crystal.
Abstract: Deuterated and isotopically dilute single crystals of K4Fe(CN)6. 3 D2O are investigated using low temperature Raman spectra. The work involves an attempt to asses the origin of the numerious OD modes using the isotope dilution technique. An estimate of the magnitude of the intra- and intermolecular interactions in formation of OD stretchings is made from available experimental data. Three crystallographically nonequivalent water molecules with different extent of vibrational distortion are established in the ferroelectric phase of the crystal.
[Russian Text Ignored].
TL;DR: The cyclic analog of JH-II was obtained in a six-step synthesis from natural (+)-limonene as starting material as mentioned in this paper, which was the first cyclic cyclic analogue to be obtained in the literature.
TL;DR: In this article, the reaction of electroreduction of TiCl 4 in acetonitrilic solution in the presence of 0.1 M LiBF 4 has been investigated.
TL;DR: In this paper, Oleum wurde als modellreaktion fur die elektrophile substitution in Azafluorenon-Systemen untersucht.
Abstract: Elektrophile Substitution in Azafluorenonsystemen - Bromierung von Azafluorenonen
Die Bromierung von 1- und 4-Aza- und 1,5-, 1,8- und 4,5-Diazafluorenonen 1–5 mit N-Bromsuccinimid, Brom in Schwefelsaure oder mit Brom 60proz. Oleum wurde als Modellreaktion fur die elektrophile Substitution in Azafluorenon-Systemen untersucht. Die Bromierung von Monoazafluorenonen mit N-Bromsuccinimid in Schwefelsaure und Diazafluorenonen mit Brom in 60proz. Oleum ist eine gunstige Methode zur Darstellung von bisher unbekannten Bromazafluorenonen. Die Strukturen der erhaltenen Bromderivate wurden mit Hilfe der 1H-NMR-Spektroskopie festgestellt. Die Ergebnisse der Substitution wurden in Abhangigkeit von der elektronischen Struktur der Azafluorenon-Systeme diskutiert.