A Facile Synthesis of 1(3)-Acylglycerols

A facile route is described for the synthesis of 1(3)-acylgiycerols for the first time through hydroxylation of allyl esters of fatty acids with the novel reagent cety1trimethy1ammonium permanganate in a non-aqueous medium.     

Increased carrier mobility in end-functionalized oligosilanes

We show that a class of oligosilane–arene σ, π-hybrid materials exhibits distinct and enhanced solid-state electronic properties relative to its parent components. In the single crystal structure, the σ-conjugation axis of one molecule points towards the π-face of a neighboring molecule due to an unusual gauche conformation. This organization is hypothesized to be beneficial for charge transport. We show that solution-deposited crystalline films of the hybrid materials show up to a 100-fold increase in space-charge limited current (SCLC) mobility relative to literature reports of photoinduced hole transport in oligosilane films. The discovery that σ, π-hybrids are more than the sum of their parts offers a design opportunity for new materials.     

Analysis of the effect of the temperature variation on transistor parameters and gain

The variations of the hybridh-parameters and the gain of the transistor with temperature have been studied by obtaining an analytical expression. The values of theh-parameters are calculated in the entire temperature range 213–473 K with the help of the expression obtained and the calculated values are in good agreement with the experimental data. The gain of the transistor extracted from the obtained values of the parameters is seen to be in excellent agreement with the experimental values.

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Zusammenfassung Die Änderung des Hybrid-Parameters und die Verstärkung des Transistors mit der Temperatur wurden untersucht, indem ein analytischer Ausdruck hierfür erhalten worden ist. Die Werte derh-Parameter wurden im ganzen Temperaturbereich von 213 bis 473 K mit Hilfe des erhaltenen Ausdrucks berechnet und die berechneten Angaben sind in guter Übereinstimmung mit den Versuchsergebnissen. Die aus den erhaltenen Parameterwerten errechnete Transistorverstärkung stimmt mit den Versuchswerten sehr gut überein.

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Résumé On a étudié, à l'aide d'une expression analytique obtenue pour le but poursuivi, la variation des paramètresh hybrides et l'amplification du transistor avec la température. On a calculé, à l'aide de cette expression, les paramètresh dans tout l'intervalle des températures comprises entre 213 et 473 K. Les valeurs calculées sont en bon accord avec les données d'expériences. L'amplification du transistor, calculée à partir des valeurs obtenues, est en excellent accord avec les valeurs d'expériences.

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h- . h 213–473 . , , , .

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Ex-student (M.Sc.) of Department of Physica, R.E.C. Waranga-506004, India.

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The work was done in the Department of Physica, R.E.C. Warangal-506004, India.

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The authors wish to express their thanks to Dr. V. V. Rao and Dr. G. S. Verma for their interest in the present project. One of us (K.S.D.) is also grateful to Dr. R. A. Rashid and Dr. R. H. Misho.     

Benzohydroxamic acid as a reductometric titrant: Determination of manganese, chromium and vanadium in steels

A method has been developed for the rapid determination of manganese and chromium by direct stepwise reductometric titration with benzohydroxamic acid, and of vanadium by titration with ascorbic acid (with benzohydroxamic acid as indicator) in the same aliquot. The method is free from the interference of common alloying elements present in steels. Some BCS steel samples have been analysed with good precision and accuracy.     

Design and in vitro analysis of SIRT2 inhibitor targeting Parkinson’s disease

Molecular Diversity - Inhibition of Sirtuin2 (SIRT2) protein rescues the α-synuclein toxicity in vitro and in vivo models of Parkinson’s disease (PD). Thioacetyl group can structurally...     

Odd Perfect Numbers: Some New Issues

Periodica Mathematica Hungarica -     

Lithium-7 NMR investigation of electrochemical reaction of lithium with SnO

We report on solid state ⁷Li NMR measurements of electrochemically lithiated SnO. At low Li contents (Li/SnO≤2), the results are consistent with the formation of amorphous Li₂O. For Li/SnO ratio of 4.3, in addition to the amorphous Li₂O phase, there are at least two distinct Sn/Li alloy environments which are similar to those observed in a reference Li_2.3Sn alloy. However the Li⁺ environments in a sample with Li/SnO ratio equal to 6.4 and an Li_4.4Sn reference alloy differ markedly. The NMR data are thus consistent with the simple model of Li insertion proposed by other groups, involving the formation of Li₂O and Li_xSn alloys (SnO+xLi→Li₂O+Li_x−2Sn), at low and intermediate Li contents. At high Li content, however, the Li_x−2Sn alloy structure is significantly different in the electrochemically lithiated SnO material, compared to that in the reference alloy.     

Anomalous magnetic hysteresis loops and smallH c1 values in highT c superconductors

We have studied the hysteresis loops of RBa₂Cu₃O₇ (R=Gd, Ho and Y) and detected anomalies in some of them. The observed anomalies support a recent prediction by Ravi Kumar and Chaddah based on an extension of Bean’s model. The anomalies indicate lowH _c1 values and we have confirmed this by studying the onset of low-field hysteresis in less than 10 Oe at 77 K for these highT _c superconductors.     

Ligand effect in epoxidatidns by hydroperoxides using molybdenum catalyst: epox idation of 3-carene

Epoxidation of (+)-3-carene with pinane hydroperoxide in presence of various transition metal catalysts, has been evaluated as a preparative method for (+)-3α,4α-epoxycarane. Catalysts based on Mo(VI) were found to be most suitable. A distinct ligand effect was noted for this oxidation and a plausible rationale is put forward.