The Addition of Bromine to Crotonic Acid and to Ethyl Crotonate under Various Conditions

Many chemical and physical reactions are accompanied by changes in weight of the reactants due to evaporation of liquids, evolution of gases, or adsorption of gases. Studies are made using data which show the manner in which the weight changes with time. Kinetic studies are made from a knowledge of the rate of loss or gain of a component. The drying of a precipitate to constant weight involves a loss in weight. Rates of evaporation of liquids from different types of surfaces involve changes of weight as a function of time. Several instruments and methods are used to follow weight changes. Gas buret systems are used to measure the volume of a gaseous component which is adding to or subtracting from the weight of a reactant. The ordinary analytical balance is used to follow weight changes by making intermittent weighings. This latter method involves tedious operations and interruptions of the treatment of the reactants. Effort has been put forth to devise instruments which will automatically weigh substances and record these weighings on some type of graph. Gregg and Wintle (1) devised a glass automatic electrical sorption balance. Gregg (2) later described a recording system for this type balance. Eyrand (3) reported a glass sorption balance of a somewhat different type. Duval (4) described a thermal balance that automatically records changes in weight on film. Described in this paper is an instrument attached to a modified ordinary analytical balance which automatically records on graph paper changes in weight as a function of time

Movement of Chlorinated Solvents and Other Volatile Organics Through Plants Monitored by Fourier Transform Infrared (FT-IR) Spectrometry

Plants have a large capacity to transfer water from soil to the atmosphere. Soluble contaminants may be carried with that water, with a relative extent of transfer that depends on their octanol-water or organic matter-water partition coefficient. We measured the transfer rate for several solvents that vary in volatility and solubility, including trichloro ethylene, trichloroethane, chloroform, dichloromethane, diethyl ether, and methyl-t-butyl ether. We tested them alone and in several combinations. An extractive Fourier Transform Infrared (FT-IR) Spectrometer (Gasmet, produced by Temet Instruments) was used to measure concentrations in the gas phase above plants which had their root system immersed in water containing the contaminant. Deuterated water was used to trace transpiration rate. Hybrid poplars (Populus deltoides x nigra) and saltcedar (Tamarix parviflora) gave similar results, indicating relatively free movement of the indicated solvents, alone or in combinations. Alfalfa (Medicago sativa) also permitted transfer of those compounds that were tested

High-speed photodetector for plasma diagnostics

Recent progress in four different classes of high-speed photodetectors are reviewed with emphasis on parameters of importance in plasma diagnostics. Two types of biplanar vacuum photodiodes are compared, the ITT F4014 and the Hamamatsu 1328. A conventional photomultiplier, the nine-stage Hamamatsu R928, has been modified to improve its bandwidth. Microchannel plate photomultipliers from two vendors have been studied. Data for the ITT F4126X, ITT F4141, Varian VPM-173, VPM-221, and VPM-225 are summarized. A hybrid photomultiplier using a PIN diode for a gain element has also been investigated. The various tubes and types provide very different limitations on system performance

Properties of Electrodeposited CuSCN 2D Layers and Nanowires Influenced by Their Mixed Domain Structure

International audienc

Emma di Resburgo

Edizione preliminare della partitura finalizzata alla prima esecuzione moderna (Wien, Konzerthaus, 7 novembre 2010

CSP ASSEMBLY RELIABILITY: COMMERCIAL AND HARSH ENVIRONMENTS

ABSTRACT The JPL-led CSP Consortium of enterprises representing government agencies and private companies has joined together to pool in-kind resources for developing the quality and reliability of chip scale packages (CSPs) for a variety of projects. Last year (1), team members reported their experience on technology implementation challenges, including design and build of both standard and microvia boards, assembly of two types of test vehicles, and preliminary aging and thermal cycling test results on trial test vehicles. Since then, more than 150 test vehicles, single-and double-sided, have been assembled and are presently being subjected to various environmental tests. This paper presents the experience of three consortium team companies on characterizing reliability behavior under four different thermal cycling environments. Lessons learned on assembly are given in a paper included in this proceedings

Stinchfield Woods

Master of ScienceNatural Resources and EnvironmentUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/101529/1/39015027286007.pd