Experimental and Computational Study of the Thermal Decomposition of 3‐Methyl‐3‐buten‐1‐ol in m‐Xylene Solution

An experimental study of the thermal decomposition of a β‐hydroxy alkene, 3‐methyl‐3‐buten‐1‐ol, in m‐xylene solution, has been carried out at five different temperatures in the range of 513.15–563.15 K. The temperature dependence of the rate constants for the decomposition of this compound in the corresponding Arrhenius equation is given by ln k (s^?1) = (25.65 ± 1.52) ? (17,944 ± 814) (kJ·mol^?1)·T^?1. A computational study has been carried out at the M05–2X/6–31+G(d,p) level of theory to calculate the rate constants and the activation parameters by the classical transition state theory. There is a good agreement between the experimental and calculated rate constants and activation Gibbs energies. The bonding characteristics of reactant, transition state, and products have been investigated by the natural bond orbital analysis, which provides the natural atomic charges and the Wiberg bond indices. Based on the results obtained, the mechanism proposed is a one‐step process proceeding through a six‐membered cyclic transition state, being a concerted and slightly asynchronous process. The results have been compared with those obtained previously by us (Struct Chem 2013, 24, 1811–1816) for the thermal decomposition of 3‐buten‐1‐ol, in m‐xylene solution. We can conclude that in the compound studied in this work, 3‐methyl‐3‐buten‐1‐ol, the effect of substitution at position 3 by a weakly activating CH₃ group is the stabilization of the transition state formed in the reaction and therefore a small increase in the rate of thermal decomposition.     

Structural and Kinetic Aspects of Blood Plasma Protein Adsorption on the Surface of Hydrophobic Polymers

Abstract

Due to the wide use of polymers in medicine, researchers are required to solve a very important problem–to understand the interaction between materials of nonphysiological origin and the surrounding biological liquids, and tissues, particularly blood.     

Improved Cope-type hydroamination reactivity of hydrazine derivatives

A systematic investigation on the metal-free, Cope-type hydroamination reactivity of hydrazides and analogues is reported. Optimization of the hydrazide structure resulted in more facile intramolecular reactivity and enabled intermolecular reactions of alkenes, thus providing a direct approach to polysubstituted hydrazides.     

Two algorithms for a plant-storehouse location problem

Summary This paper considers the following assignment problem. There are some groups of plants, each group producing a different commodity. There are some consumption areas, each containing a number of storehouses and wanting a certain amount of all the commodities. The problem consists of finding the assignment of storehouses to plants which minimizes the overall cost, consisting of fixed charges associated to all storehouses and plants, and of transportation costs. For the solution of this problem, which can be called a plant-storehouse location problem, two algorithms are presented. The first algorithm makes use of a branch and bound technique; the second is based on a decomposition technique, which follows directly from the Dynamic Programming.The classic plant location problem is a particular case of the problem discussed in this paper.

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Zusammenfassung In dieser Arbeit wird folgendes Zuordnungsproblem untersucht. Gegeben sind einige Fabrikgruppen, die jeweils verschiedene Waren herstellen, und einige Verbrauchsgebiete mit jeweils einer Anzahl von Lägern und einem bestimmten Bedarf an diesen Waren. Gesucht ist eine gesamtkostenminimale Zuordnung der Läger zu den Fabriken. Die Gesamtkosten setzen sich aus den Transportkosten und fixed charges für jede Fabrik und jedes Lager zusammen. Für dieses spezielle Standortproblem werden zwei Algorithmen entwickelt. Während der erste Algorithmus auf der Branch and Bound-Technik aufbaut, basiert der zweite auf einer aus der dynamischen Optimierung entwickelten Dekompositionstechnik.Das klassische Standorproblem ist ein Sonderfall des in dieser Arbeit behandelten Problems.

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Deutsche Übersetzung:Zwei Algorithmen zur Lösung von Fabrik-Lagerhaus-Standortproblemen.

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This work has been supported by Consiglio Nazionale delle Ricerche (C. N. R.), Roma, Italy.

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The authors are with the Istituto di Elettrotecnica ed Elettronica, Laboratorio di Controlli Automatici, Politecnico di Milano, Milano, Italy.     

The minimal cost maximum matching of a graph

Summary This paper deals with the problem of finding the maximum matching of a weighted graph, having the minimum cost. This problem is solved via a branch and bound algorithm, derived directly fromLand andDoig's technique. The linear programming problem associated with each step of the procedure is solved through a primal-dual algorithm.

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Zusammenfassung Diese Arbeit beschäftigt sich mit demmatching problem. In einem gewichteten Graphen ist dasmaximal matching mit minimalen Kosten gesucht. Zur Lösung wird ein vonLand undDoig beschriebener Branch-and-Bound-Algorithmus verwendet. Das sich je Iterationsschritt ergebende LP-Problem wird mit einem Primal-Dual-Algorithmus gelöst.

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The authors are with the Laboratory of Automatic Control, Istituto di Elettrotecnica ed Elettronica, Politecnico di Milano, I-20133 Milano, Piazza Leonardo da Vinci, 32.     

A simple method for extracting both active oily and water soluble extract (WSE) from Nigella sativa (L.) seeds using a single solvent system

The current study provides a way of extraction for both active NSO and WSE from Nigella sativa seeds using 98% methanol. About 1?kg of ground seeds was macerated by 1:2.5 w/v (g/mL) for 72?hours. After rotary evaporation and 7 days of continuous drying and chilling at 50 and 4?°C, NSO and WSE were obtained at the same instant. Solubility tests of 24 solvents and 11 thin layer chromatographic analyses while 2, 2-diphenyl-1-picrylhydrazyl free radical scavenging assay of NSO (73.66) , WSE (33.32) and NSO?+?WSE (78.22) against ascorbic acid (IC50?=?4.28?mg/mL) was performed. WSE was found to be highly soluble in water and 5% NaOH exhibiting the same Rf value of 0.95 for EtOH:DMSO (9:1) against the honey. WSE has revealed more than twofold higher anti-oxidant activity than others. Formulation of WSE with Tualang honey may provide better targeted hydrophilic drug delivery systems.     

高聚合度Ⅱ-型聚磷酸铵的合成

用聚合反应-热处理两段工艺合成了高聚合度的聚磷酸铵（APP）阻燃材料,其结构经XRD,粒度及平均聚合度表征。优化反应条件为：磷酸氢二铵1mol,n（磷酸氢二铵）：n（五氧化二磷）：n（脲）：1．0：1．0：0．3．干燥氨气氛下于290℃反应30min,再经250℃-280℃后处理100min-110min。APP的平均聚合度大于150,粒度小于50μm。