very slow induced decomposition of cumene hydroperoxide was reported to occur with AIBN.19 Competitive Reactions.-Competitive autoxidations were carried out with an equimolar mixture of two substituted isopropylbenzenes (each ca. 1.2-0.6 M ) in chlorobenzene at 60' in the presence of AIBN (0.26-0.09 M ) . Aliquots (each 1 ml) were taken out at appropriate intervals of time and reduced with 15% KSH in aqueous methanol. After completion of reduction, the solution was washed with water, extracted with two 4-ml portions of chloroform, and analyzed by means of glpc. The products were analyzed by a Yanagimoto gas chromatograph with a flame ionization detector, Model GCG-%OF, employing (19) J. A. Howard and K. U. Ingold, Can. J . Chem., 46, 2655 (1968). a 1.0 m X 2.5 mm column packed with Apiezon Grease (5%) on Chamelite CS of 80-100 mesh using NS as a carrier gas at 160-220'. The internal standards for glpc were nitrobenzene for cumene and m-diisopropylbenzene for isopropylcumyl hydroperoxide End isopropylcumyl alcohol. The relative rate constants of competitive oxidation were calculated from the equation k = km/k, = log [ ( b -y)/b]/log[(a -%)/a]. Here, a and b are initial concentrations of substrates and 5 and y are corresponding concentrations a t time t.Acknowledgment. -The authors wish to thank Dr. RII. Yamashita for his helpful advice in performing these experiments.
We would like to thank Professor J. K, Crandall for communication of his results prior to publication. (11)
The US Department of Homeland Security, and other state and federal agencies, continues to express concern over the potential use of radioactive isotopes as a weapon of terror. Few emergency medicine and critical care physicians are familiar with the care and treatment of an accidentally or intentionally irradiated patient who is contaminated externally or internally. This article reviews basic radiobiology and the variety of clinical signs and symptoms exhibited by victims exposed to radiation. Preparation for patient receipt and emergency care, followed by definitive diagnosis using biodosimetry is also presented. Therapeutic measures continue to evolve for externally and internally exposed victims, including those with combined injuries caused by burns and trauma.
The stepwise synthesis of specifically substituted trialkyl-3,4-dihydro-l (2H >naphthalenones (1-tetralones), the corresponding naphthalenes, and partially hydrogenated derivatives, several having the cadalene-type 1,4,6 substitution, has been reexamined. Individual steps have been improved and new approaches with fewer steps and higher overall yields have been devised. Syntheses utilizing lactones in Friedel-Crafts reactions were also carried out. These latter Friedel-Crafts reactions are responsible for rearrangements during tetralone syntheses which were previously attributed to polyphosphoric acid during cyclization.The synthesis of cadalene (1) became important to us as a route to pure polyalkylnaphthalenes and as a (1) E.
A new polymer gelling agent has been developed to help satisfy the growing demand for "clean" hydraulic fracturing fluids. This polymer is a guar derivative that exhibits the desirable characteristics of conventional guar and that leaves low residue upon breaking. The derivatized guar was evaluated for its ability to function as a fracturing-fluid gelling agent in comparison with both a conventional guar and a nonionic cellulose derivative. The guar derivative possesses a number of advantages over both the conventional guar and the cellulose derivative. Laboratory experimental data and field results are presented. Introduction Hydraulic fracturing has been used successfully for oil- and gas-well stimulation for about 27 years. During this time the size of the treatments has grown from the original "tank of oil and sack of sand" to the current massive hydraulic fracturing treatments, entailing several hundred thousand gallons of fluid and large amounts of sand. These massive treatments have become routine in some areas of this country. Although many types of fluids have been used successfully, aqueous fluids have been preferred recently. Because of economic and safety considerations, aqueous fluids will likely continue to be preferred. Treatment designs usually require that the fluids possess a particular apparent viscosity. These stipulated viscosities are particular apparent viscosity. These stipulated viscosities are often many times higher than that of the base fluid in its natural state. The increased apparent viscosities are generally attained by the addition of hydrophilic polymeric "gelling agents." A variety of gelling agents for aqueous fluids is available. Each gelling agent possesses inherent chemical properties that often make it particularly applicable for a special function. These properties are a direct result of the chemical structure and stereochemistry of the repeating unit of the polymer, and the resulting conformation or macrostructure that the polymer assumes in the fluid. Polysaccharides, such as the guar polymer, possess many of the properties desired of a gelling agent. However, the relatively high percentage of insolubles (residue) present in commercial guar has been a matter of serious concern. Many believe that guar-gum residue can contribute to permanent formation and fracture conductivity damage. Because of the complexity of the situation, experimental evaluation of the over-all effect of this residue on the formation permeability and fracture flow capacity is difficult. However, there should be no question that the presence of the residue could result in damage to the formation and the proppant system, and that a reduction in the amount of residue proppant system, and that a reduction in the amount of residue present diminishes this possibility. present diminishes this possibility. A new low-residue, derivatized-guar (derivatized polysaccharide) gelling agent has been developed. This chemically polysaccharide) gelling agent has been developed. This chemically modified guar results in an 85-percent reduction in inherent residue over conventional guar gum, yet retains the desirable properties of the guar polymer. In addition, it provides an properties of the guar polymer. In addition, it provides an extension of guar chemistry and versatility into several new approaches for designing hydraulic fracturing fluids. This versatile polymer has application in most aqueous and polymer-emulsion hydraulic fracturing processes. polymer-emulsion hydraulic fracturing processes. In addition to possessing the obvious advantage of low residue, this new material can be dispersed controllably in aqueous fluids, thereby effectively reducing gel lumping tendencies. The result is a smooth, lump-free gel. It yields equivalent or slightly higher apparent viscosity values in fresh water and the usual brines compared with the old, conventional, guar-gum gelling agents. Alcohol tolerance of this new material is good, and it is readily complexed or crosslinked in water or alcohol-water mixtures with crosslinking agents. Fluids prepared with this new polymer may be manipulated to achieve temperature stability surpassing that of any gelled-water fracturing fluid containing the polysaccharides we have used in the past. SPEJ P. 5
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