Eine Beziehung zwischen der Dielektrizitätskonstante und dem inneren Druck reiner Flüssigkeiten bei verschiedenen Temperaturen

Zusammenfassung Gegenstand der vorliegenden Arbeit ist zu untersuchen, ob mit steigender Temperatur eine einfache Beziehung zwischen der Änderung der Dielektrizitätskonstante (DK) und dem inneren Druck reiner Flüssigkeiten besteht. Unter Benützung eines von uns früher auf Grund eines vonYoung undLaplace entdeckten Zusammehanges abgeleiteten Ausdruckes erhielten wir einen Faktor, dessen Vergleich mit derDK bei verschiedenen Temperaturen hinreichend ist, um als Vergleich derDK mit dem inneren Druck bei den entsprechenden Temperaturen zu dienen. Der Vergleich der beiden Größen wird graphisch durchgeführt. Wir beobachteten bei 12 der untersuchten 14 Flüssigkeiten, daß sich dieDK linear mit dem inneren Druck ändert. Wasser und Eisessig sind Ausnahmen. Im Hinblick auf das Kriterium vonTakeuchi foldt, daß die Molekularkräfte in allen untersuchten Flüssigkeiten elektromagnetischer Natur sind, ausgenommen Eisessig, in welchem sie elektrostatischer Natur sind.Department of Technology Annamalai UniversityMit 12 Abbildungen     

Simulation of isotopic selectivities and isotope ratio enhancement factors for gadolinium and lanthanum using narrow band laser excitation

Isotopic selectivities and isotope ratio enhancement factors have been calculated for 4f⁵5d6s^{2 9}D ₅ ⁰ -4f⁷5d6s6p ⁹D₆ (585.622 nm) transition of gadolinium and for 5d6s^{2 2}D_3/2-5d6s6p ⁴F _3/2 ⁰ (753.9 nm) transition of lanthanum by simulating the spectra assuming natural isotopic abundance of the samples. The atomic line shapes are assumed to be Lorentzian. Isotopic selectivities and isotope ratio enhancement factors for single step excitations have been computed. The isotope ratio enhancement factors estimated by us are half the value obtained by Young. et al. This is because the isotope ratio enhancement obtained by them is for a two colour RIMS where as our computations for selectivities are for a single step excitation. Considering the statistical error in the experimental values, our estimated isotopic selectivities are in good agreement with the available experimental data.     

Effect of temperature on the ML of Au doped(Zn,Cd)S mixed phosphors

In this paper the effect of temperature on the mechanoluminescence of Au doped phosphors of(Zn,Cd)S is described.It is found that the ML disappears beyond a particular temperature.The temperature dependence of ML intensity follows the relation I =I_T~O(1-TIT_C)~n,where I_T~O is a constant,n is the slop of log I_T versus log(1- TIT_C) plot which lies between 0.9 and 1.10,T_C is the temperature at which ML disappear.It is found that the ML intensity in(Zn,Cd)S:Au disappear at 600 K.     

An efficient synthesis of 2-benzoxepines from Morita-Baylis-Hillman adducts using heterogeneous recyclable catalysts

2-Benzoxepines have efficiently been synthesized from Morita-Baylis-Hillman adducts, alkyl 3-aryl-3-hydroxy-2-methylenepropanoates by treatment with HCHO catalyzed by silica supported perchloric acid (HClO4.SiO2) or Amberlyst-15 in CH2Cl2 under reflux for a short period of time (1.5-2.5 h). The catalyst can be recovered and recycled. The antibacterial properties of the new 2-benzoxepines were studied but no activity was found.     

High-pressure synthesis of A15 Nb3Si phase from amorphous NbSi alloys

An amorphous phase has been produced in a binary Nb-19 at .% Si alloy by rapidly quenching from the molten state. Primary decomposition of the amorphous phase by annealing resulted in the production of a small quantity of the A15 cubic Nb₃Si phase. However, long annealing treatments led to the complete transformation to the equilibrium phases. Application of high pressure of 10 GPa during decomposition of the amorphous phase resulted firstly in the improved stability of the amorphous phase and secondly, in the production of a much larger quantity of the A15 cubic Nb₃Si phase. The lattice parameter of this phase was calculated to be 0.515 nm, in conformity with the previous investigations.     

Eine Prüfung der neuen Viskositätsgleichung für Lösungen bis zur Sättigung

Zusammenfassung Man fand jetzt, daß die Exponentialgleichung vonSuryanarayana undVenkatesan, welche Viskosität und Konzentration einer Elektrolytlösung bei einer gegebenen Temperatur verbindet, auf nichtelektrolytische wäßrige Lösungen von Glucose, Galactose, Propionamid, Lactose, Fructose, Maltose und Rohrzucker, ferner auf Kaliumjodid in Methylalkohol und Naphthalin in Benzol und Toluol anzuwenden ist.Mit 5 Abbldungen     

On recent existence theorems in the theory of optimization

A condition recently proposed is shown to imply the weak compactness inH ^1,1 and actually is equivalent to another condition previously proposed by the authors. Once compactness is proved, then existence theorems follow from lower closure theorems also previously proved by the authors, and extended to Pareto problems. The present analysis adds to the recent work of Goodman concerning the equivalence of seminormality conditions with concepts of convex analysis and lattice theory.Paper received February 2, 1979.     

Nemitsky's operators and lower closure theorems

This paper focuses on certain analytic criteria given by the authors in earlier works, for the geometric property of upper semicontinuity of set-valued functions, used in the proofs of lower closure theorems, and hence in existence theory. In particular, it is observed that, under Filippov-type condition (namely, when the set of controls is bounded in measure or in norm), mere Carathéodory-type continuity of the relevant functionsf is sufficient to guarantee a weak form of property (Q), and in turn the lower closure theorems.This work has been partially supported by Research Project AFOSR-71-2122 at the University of Michigan, Ann Arbor, Michigan.     

Thermoluminescence study of ZnS:Cu nanoparticles

In this paper, we report on the TL glow curves and kinetic parameters, activation energy, order of kinetics, and the frequency factor of copper-doped zinc sulfide nanophosphor under UV irradiations. The sample was prepared by the chemical precipitation method; thereafter, the TL glow curves were recorded for different doses of UV exposure at a heating rate of 10 °C/s. The synthesized nanophosphor exhibited TL glow peaks at 241, 255, and 281 °C for the heating rate 10 °C/s at different doses of 5, 10, and 15 min of UV exposure. The kinetic parameters activation energy E, the order of kinetics b, and the frequency factor S of synthesized nanophosphor of ZnS:Cu have been calculated by using a peak shape method while the trap depth was determined using different formulae. The sample was characterized by XRD (X-ray diffraction) and SEM (scanning electron microscope).