Fabrication of Transparent Electrooptic PLZT Ceramics by Atmosphere Sintering

PLZT electrooptic ceramics were fabricated by a unique atmosphere sintering technique. The ceramics produced were significantly more transparent than those obtained by ordinary O₂ sintering methods; in fact, they were comparable in transparency to those obtained by hot-pressing. To achieve good transparency, the powder must be batched with excess PbO, which at the sintering temperature is present as a liquid phase at the grain boundaries. Sintering was conducted at 1200°C for 60 h in an atmosphere containing O₂ and a relatively high partial pressure of lead oxide.     

Thermodynamic Analysis and Kinetic Implications of Chemical Vapor Deposition of Sic from Si-C-C1-H Gas Systems

Experimental results compiled from the literature were compared to thermodynamic calculations of the most stable proportion of condensed phases to deposit from gas mixtures of Si-C-Cl-H. The calculations indicated that the predominant gas molecules participating in a deposition process are chlorides and chlorosilanes for silicon and methane and acetylene for carbon. The mismatch of the calculated and experimentally determined phase boundaries at 1473 and 1600 K led to the conclusion that silicon deposition occurs faster than carbon deposition in proportion to their partial pressures. The probable reason is that silicon-bearing gas molecules have a greater sticking probability on polar Si and Sic surfaces because of their asymmetric geometries.     

Interaction of β-cyclodextrin with Enantiomers of Limonene and Carvone

The inclusion complexes of β-cyclodextrin with two pairs of chiral flavor compounds, limonene and carvone, were used to evaluate the chiral interaction. Thermal transition was examined by DSC and crystalline properties by x-ray diffractometry. The overall DSC thermograms and X-ray diffraction patterns were very similar between the chiral isomers. A difference of about 3 joules/g complex was observed between the chiral isomers of both limonene and carvone. The only apparent difference in X-ray diffraction patterns between chiral complexes occurred at a θ of 11.8°.     

Lactobacillus spp. from Washington State Wines: Isolation and Characterization

Species of Lactobacillus were isolated and identified from commercial Washington state grapes and wines including L. brevis (4 strains), L. hilgardii (4), L. plantarum (3), and L. fructivorans (1). Unlike other strains, L. brevis and L. pluntarum grew in media at relatively low pH (pH 3.16 and 3.34). Sulfur dioxide inhibited all strains as growth was delayed in 33 mg/L total SO2 (pH 3.5). None of the strains grew in 12% or 14% ethanol. Alcoholic fermentations of two grape musts were not slowed in the presence of strains of L. brevis, L. hilgardii, or L. plantarum.     

High-Yield Synthesis of Si3N4/SiC Ceramic Materials by Pyrolysis of a Novel Polyorganosilazane

The action of basic catalysts such as KH on the ammonolysis products of CH₃SiHCl₂, (CH₃SiHNH)_n, results information of polysilazanes of intermediate molecular weight (600 to 1800). Pyrolysis of these polysilazanes gives ceramic materials, which appear to be mixtures of Si₃N₄, SiC, and C, in yields of 80 to 85%.     

A CREEP STRAIN GAUGE FOR IN-PILE MEASUREMENTS ON REACTOR PRESSURE TUBES

A creep gauge based on a differential transformer and mechanical magnification measures a diametral expansion of less than 0-1X10-⁶ in/in per hour on a 5 in diameter tube at 300 deg. C in a reactor environment.     

ALTERNATE STORAGE SYSTEMS FOR THE PRODUCTION OF CANNED BLACK RIPE OLIVES

SUMMARY— The storage of freshly harvested olives in systems other than the traditional sodium chloride brine was investigated in an attempt to provide an alternative storage system which would reduce the present saline pollution potential of the dive canning industry. Chemical salts used as fertilizers were partially successful in holding olives for several months without spoilage. Ammonium nitrate brines could be used for periods up lo 15 wk; however, it was difficult to remove the salt completely during preparation far canning. Brines containing ammonium sulfate (with the pH controlled by the addition of H₂SO₄) held olives for 6 mo. The difficulties in completely removing ammonium sulfate from the olives limited the commercial potential for this type of storage. Food grade glycols containing bacteriostats can be used to store olives for periods of over 6 mo. Olives submerged in propylene glycol-diethyl pyrocarbonate mixtures showed severe shriveling. The recovery from shriveling on subsequent preparation was satisfactory only for the smaller-sized olives. A similar result was obtained far olives stored in a mixture of glycerol-benzoic acid-sorbic acid. The most promising storage system developed in this study was a mixture of water-propylene glycol-benzoic acid-potassium sorbet-HCI. By using KOH in place of NaOH for the chemical curing preparation steps, it was possible to prepare canned olives with essentially no generation of liquid waste containing sodium ions.     

MAKING ENDS MEET: OPTIONS FOR PROPERTY TAX REFORM IN DETROIT

Current property tax policies in Michigan severely constrain the ability of the City of Detroit to raise sufficient revenues, particularly in a weak economy. Almost half of the land area of the city does not contribute to the property tax effort and the valuation of the taxable properties has fallen substantially since the Great Recession. This article considers alternative definitions of the city's tax base, including taxes based on land value or land area, as well as special assessments for specific services. These reform options are found to have considerably different impacts on different classes of real property.