Analysis of certain mixtures ofα-Amino acids

Summary -Amino acids are determined by reaction with perinaphthindan-2,3,4-trione hydrate to form dihydroxyperinaphthindenone which is titrated with chloramine-T in the presence of acidified bromide and methyl red. The thiol group of cysteine is blocked by cyano-ethylation before determination. Some amino acids can be directly titrated with chloramine-T in the presence of bromide and methyl red, e. g., cysteine (after cyanoethylation), methionine and lanthionine, or in the presence of iodide and starch, e. g., cysteine (after tetrathionate reaction) when concomitant amino acids do not interfere. These methods are used to analyze model mixtures of cysteine with serine, methionine with glycine and cysteine with methionine.

---

Analyse bestimmter Gemische von -Aminosäuren

Zusammenfassung -Aminosäuren werden mit Peri-Naphthindan-2,3,4-trion-hydrat umgesetzt, wobei sich Dihydroxyperinaphthindenon bildet, das mit Chloramin T in der Gegenwart von angesäuertem Bromid und Methylrot titriert wird. Die Thiolgruppe des Cysteins wird vor der Bestimmung durch Cyanoäthylierung blockiert. Manche Aminosäuren können unmittelbar mit Chloramin T in der Gegenwart von Bromid und Methylrot titriert werden, z. B. Cystein (nach Cyanoäthylierung), Methionin und Lanthionin, oder in Gegenwart von Jodid und Stärke Cystein (nach Umsetzung mit Tetrathionat), wenn die begleitende Aminosäure nicht stört. Diese Verfahren wurden benutzt, um Modellgemische von Cystein mit Serin, Methionin mit Glycin und Cystein mit Methionin zu analysieren.

     

Synthesis of some new fluorine containing 3-dialkylaminomethyl indoles, 3-indolylglyoxamides and tryptamines

Several new 2-(fluoroaryl)-3-dialkylaminomethylindoles, 3-acetyl-2-(fluoroaryl)-indoles, 2-(fluoroaryl)-3-indolylglyoxamides and corresponding tryptamines have been prepared as possible psychopharmacological agents. 2-(Fluoroaryl)-indoles have been synthesized by theFischer indole synthesis. 2-(Fluoroaryl)-indoles on treatment with oxalyl chloride and subsequent reaction with amines, gave 2-(fluoroaryl)-3-indolylglyoxamides. Some of these indolylglyoxamides were reducted with lithium aluminium hydride, to the corresponding tryptamines. 2-(Fluoroaryl)-indoles when subjected toMannich reaction afforded 3-dialkylaminomethyl-2-(fluoroaryl)-indoles. All these new compounds have been characterized by IR spectral studies.Possible Psychopharmacological Agents, Part XII, Part XI, J. Indian. Chem. Soc.57, 423 (1980).     

1,4-cycloaddition of nitrosobenzene to N-ethoxycarbonylazepine

A new stable product from the reaction of nitrosobenzene and N-ethoxycarbonylazepine is shown to be a 1,4-cycloadduct.     

Stability analysis of structurally unstable man–machine system involving time delays

In this paper, a structurally unstable man–machine system is considered and a rigorous mathematical analysis is performed to study the influence of time delays in the control force on stability of the equilibrium solution of this system. Results on stability, instability and conditions for the preservation of stability (instability), besides the existence of bifurcation are presented.     

Transient Analysis for State-Dependent Queues with Catastrophes

Abstract

Queueing systems with catastrophes and state-dependent arrival and service rates are considered. For two types of queueing systems namely, queues with discouraged arrivals and infinite server queue, explicit expressions for the transient probabilities of system size are obtained by using continued fractions technique. Some system performance measures and steady-state probabilities are studied. The effect of system parameters on system size probabilities are also illustrated numerically. It is observed that the steady-state probabilities differ when catastrophes are present, while they are identical in the absence of catastrophes.     

利普希茨伪紧缩映射下的利普希茨摄动迭代的Bruck公式

在非线性分析中,处理伪紧缩算子及其变形的解(不动点)存在性和近似性,从而使演化方程的求解已经发展成为一个独立的理论.使用近似不动点技术,采用摄动迭代方法,目的是证明利普希茨伪紧缩映射序列的收敛性.该迭代方法适用于比利普希茨伪紧缩算子更一般的非线性算子以及Bruck迭代法无法证明其收敛性的情况.推广了Chidume和Zegeye的结果.     

The sojourn time and related characteristics of the age-dependent branching process

An age-dependent branching process where disasters occur as a renewal process leading to annihilation or survival ofall the cells, is considered. For such a process, the total mean sojourn time of all the cells in the system is analysed using the regeneration point technique. The mean number of cells which die in timet and its asymptotic behaviour are discussed. When the disasters arrival as a Poisson process and the lifetime of the cells follows exponential distribution, elegant inter-relationships are found among the means of (i) the total number of cells which die in timet (ii) the total sojourn time of all cells in the system upto timet and (iii) the number of living cells at timet. Some of the existing results are deduced as special cases for related processes.     

Superquantiles at Work: Machine Learning Applications and Efficient Subgradient Computation

Set-Valued and Variational Analysis - R. Tyrell Rockafellar and his collaborators introduced, in a series of works, new regression modeling methods based on the notion of superquantile (or...     

Maximal Contractive Tuples

Maximality of a contractive tuple of operators is considered. A characterization for a contractive tuple to be maximal is obtained. The notion of maximality for a submodule of the Drury–Arveson module on the \(d\) -dimensional unit ball \({\mathbb {B}}_d\) is defined. For \(d=1\) , it is shown that every submodule of the Hardy module over the unit disc is maximal. But for \(d\ge 2\) we prove that any homogeneous submodule or submodule generated by polynomials is not maximal. A characterization of maximal submodules is obtained.