Pyrolysis kinetics for Green River oil shale from the saline zone

The nature of the organic and mineral reactions during the pyrolysis of Saline-zone Colorado oil shale containing large amounts of nahcolite and dawsonite has been determined. Results reported include a material-balanced Fischer assay and measurements of gas evolution rate of CH₄, C₂H_x, H₂, CO and CO₂, Stoichiometry and kinetics of the organic pyrolysis reactions are similar to oil shale from the Mahogany zone. X-ray diffraction and thermogravimetric analysis results are used to help determine the characteristics of the mineral reactions. Kinetic expressions are reported for dawsonite decomposition, and it is demonstrated that the temperature of dolomite decomposition is substantially lower than for Mahogany-zone shale because of the presence of the sodium minerals.     

THE REACTIONS BETWEEN POLYPHENOLS AND ALDEHYDES AND THE INFLUENCE OF ACETALDEHYDE ON HAZE FORMATION IN BEER

The reactions and interactions between proteins and polyphenols are, among other phenomena, responsible for haze formation in beer. The participation of aldehydes in the polymerisation of polyphenols is considered. The formation of phenolic Baeyer-type condensation products containing phenolic residues linked by CH₃CH-bridges through reaction with acetaldehyde is possible at the pH of beer (4.0). These and other reactions with acetaldehyde in beer participate in beer haze formation.     

Fat emulsions. Effect of polyoxyethylene and alkyl content of emulsifiers on stability to sterilization

Summary When a given system of emulsifiers of known compositions and molecular weights was employed, it was found that in order for fat emulsions of 15% oil content to be stable to the heat required for sterilization, the emulsifiers must meet definite requirements. Minimum weight percentage of total lipophilic groups should be 0.29%; minimum weight percentage of total hydrophilic groups should be 0.57%; the polyoxyethylene groups of emulsifiers containing such groups should account for at least 70% of the mole weight of these emulsifiers; the lipophilic/hydrophilic ratio should be about 0.5. The minimum content of lipophilic and hydrophilic groups was found to be an additive total of these groups as provided by the complete emulsifying system whether composed of individual or multiple emulsifying agents and whether of similar or dissimilar functional groups. With the emulsifiers used, an acyl group greater in length than 12 carbon atoms was found to be necessary to prepare cottonseed oil emulsions which were stable to heat. Resistance of emulsions to breakage by mechanical shock was imparted by a rather large amount of lipophilic groups, so that the lipophilic/hydrophilic ratio was 1 or over. Presented at fall meeting of American Oil Chemists' Society, Cincinnati, O., September 30–October 2, 1957. This work was supported in part by funds from the Office of the Surgeon General, U. S. Army. One of the laboratories of the Southern Utilization Research and Development Division, Agrciultural Research Service, U. S. Department of Agriculture.     

The optical control of IMPATT oscillators

This paper describes methods of controlling the frequency of IMPATT oscillators using optical rather than electrical signals. Analytic theories of optical tuning and injection locking are presented. Results from a comprehensive large signal computer model of the optically controlled IMPATT oscillator are given, illustrating the importance of the composition of the optically generated current on the optical control performance and demonstrating the capability of optical control for rapid frequency tuning. Finally, recent experimental work on optical tuning effects in W-Band IMPATT oscillators is presented.     

Environmental stress cracking of polyethylene

Deformation of polyethylene in environmental stress cracking (ESC) agents results in changes in both the mechanism of deformation and structure of the resulting drawn material. Stress-cracked failure surfaces are highly fibrillar, the fibrils having less elastic recovery than those in samples drawn in air. In thin films drawn in ESC agents, small blocks of the lamellae remain undrawn and attached to the fibrils drawn across micronecks. The ESC agents are suggested to weaken the cohesion between the fibrils in samples drawn beyond yield as well as the cohesion between mosaic blocks or similar structural elements in the original lamellae as they are being reoriented to form the fibrils. The stress is thus supported by a number of independent, nonuniform fibrils rather than a coherent structure; the weakest of these fibrils fail in turn as the crack propagates through the sample.     

Cyclotron resonance studies of electron dynamics in ET charge transfer salts

Microwave cyclotron resonance measurements on (ET)₂NH₄Hg(NCS)₄ have revealed a series of harmonics in addition to the fundamental absorption. An attempt is made to account for the associated cyclotron effective masses in terms of a renormalised band of quasiparticles.     

Relationship between effective mass and superconducting critical temperature in the organic superconductor κ-(BEDT-TTF)2Cu(NCS)2

We report high pressure magnetotransport on the organic superconductor κ-(BEDT-TTF)₂Cu(NCS)₂. The observation of Shubnikovde Haas and magnetic breakdown oscillations has allowed the pressure dependences of the Fermi surface topology and quasiparticle effective masses to be deduced and compared with simultaneous measurements of the superconducting critical temperature T_c. The data strongly suggest that the enhancement of the effective mass and the superconducting behaviour are directly connected. The results are fitted by calculations of the linearised Eliashberg equations.     

Interaction of fibronectin (FN) cell binding fragments and interleukin-8 (IL-8) in regulating neutrophil chemotaxis

This study investigated the possible interaction of FN fragments in regulating IL-8-mediated neutrophil chemotaxis in vitro using Neuroprobe microchambers. Human neutrophil suspensions were incubated with purified FN fragments or an RGD-containing peptide and allowed to migrate in response to chemotactically active concentrations of human recombinant IL-8. The 120-kD fragment of FN containing the RGD sequence or an RGD peptide (GRGDSP) inhibited IL-8-mediated neutrophil chemotaxis; however, these RGD peptides did not inhibit neutrophil chemotaxis in response to other chemotactic agents. Furthermore, FN fragments not containing the RGD sequence had no effect on IL-8-mediated chemotaxis. These data suggest that directed migration of neutrophils in response to IL-8 is inhibited in the presence of cell-binding fragments of FN and may represent a local mechanism for terminating neutrophil migration at areas of tissue injury.