CONTRACTION CHARAClFRlSTlCS OF MOLDED CERAMICS DURING DRYING

ABSTRACT

The characteristics of drvine and contraction (shrinkage) of molded ceramics were expenmentally studied to clarify the effects of drying conditions on contraction behaviors or deformation during drying processes. Mikawa-Shanshu clay molded into spheres or slabs was used as a sample which underwent convective drying by hot air.

Three periods of preheating, constanl rate and falling rate existed, and the contraction was observed mainly in the preheating and constanl rate periods for all samples. It is also observed that the behavior of ihe contraction of molded clay is inflienced significantly by drying conditions. The higher drying rate makes the contraction of clay more remarkable in the preheating and constant rate periods. This behavior could not be explained from the difference of the moisture content distribution among runs. However, it is suggested that the inside parts of molded ceramics may be subjected to the strong compressional stresses and the strain-stress in the sample would Influence the contraction behavior when he gradient of moisture content distribution becomes steeper with increase in the drying rate.     

Sex Pheromones of Two Melittini Species, <Emphasis Type="Italic">Macroscelesia Japona</Emphasis> and <Emphasis Type="Italic">M. Longipes</Emphasis>: Identification and Field Attraction

Two Melittini species, Macroscelesia japona and M. longipes (Lepidoptera: Sesiidae), are native to Japan, but occupy different localities as their host plants seldom grow together. The contents of the sex pheromone gland of adult females of both species, obtained after rearing larvae collected from the field, were investigated by gas chromatograph-electroantennogram detection (GC-EAD) and gas chromatograph-mass spectrometry (GC-MS) analyses. Two GC-EAD-active components were found in a crude extract of M. japona female pheromone gland, and identified as (2E,13Z)-2,13-octadecadien-1-ol (E2,Z13-18:OH) and (2E,13Z)-2,13-octadecadienal (E2,Z13-18:Ald). The average ratio of these two components was about 1:10. In the field, M. japona males were attracted to traps baited with E2,Z13-18:Ald alone, but the strongest attraction was observed with a 1:100 mixture of E2,Z13-18:OH and E2,Z13-18:Ald. The same two components were found in extracts of M. longipes females, but in a markedly different ratio. Male M. longipes were attracted most strongly to lures containing a 20:1 mixture of E2,Z13-18:OH and E2,Z13-18:Ald, although some males were also attracted to lures with E2,Z13-18:OH alone. Although the two species do not generally occur in sympatry, our data indicate that, in the event of overlap, cross attraction of the two species is unlikely.     

Fat Utilization in Healthy Subjects Consuming Diacylglycerol Oil Diet: Dietary and Whole Body Fat Oxidation

Several studies in animals and humans have reported beneficial effects of diacylglycerol (DAG) on lipid and energy metabolism. We assessed the effect of DAG versus triacylglycerol (TAG) treatment on total energy expenditure (TEE), total fat oxidation (Fox) and respiratory quotient (RQ), and measured the oxidation rate of each oil using a respiratory chamber and the 13C-stable isotope. Eleven healthy subjects participated in a double-blind, randomized crossover study. Subjects consumed an energy maintenance diet consisting of 55% of total calories from carbohydrate, 15% from protein and 30% from fat during both the 3-day pre-chamber and 36-h chamber period. Fifty percent of the fat was test oil, containing either DAG oil or TAG oil. The oxidation rate of ingested test oils was determined by monitoring 13CO2 excretion in the breath from 13C-labeled diolein or 13C-labeled triolein. There were no significant differences in TEE, RQ and total Fox between the DAG and TAG treatment in the overall analysis. In the subgroup analysis, DAG treatment decreased RQ significantly in subjects with a high fat ratio (HFR) compared to TAG treatment. In addition, ingested diolein oxidation in DAG treatment was significantly faster than triolein oxidation in TAG treatment in the HFR group. Enhanced fat utilization with DAG treatment and rapid oxidation of ingested DAG may, at least in part, explain the greater loss of body weight and body fat related to DAG consumption found in the weight-loss studies.     

Fabrication and characterization of components for cube shaped micro tubular SOFC bundle

Solid oxide fuel cells (SOFCs) have the highest energy efficiency among various power generators. However, SOFCs generally have problems regarding to heat stress due to the heating cycle during cell operation, especially quick start-up/shut-down and the size of SOFC systems, which limit their application use. Micro tubular SOFCs are expected to be a solution to these problems because they are considered to be robust for repeated cycling under rapid changes in cell operating temperatures. If highly dense micro tubular SOFC stacks become available, it will accelerate development of SOFC systems, as well as increase a variety of applications. Our study aims to fabricate compact and high power SOFC bundles, which are composed of tubular SOFCs with the diameter of sub-millimeters. In this study, as the first stage of the development, processing technologies of tubular SOFCs and cube shaped cathode matrices were examined. Micro tubular SOFCs were fabricated using extrusion and co-firing techniques. The tubular SOFCs were then, arranged in the cathode matrices, which were piled up to be a cube shaped bundle. Each component of the cube shaped micro tubular SOFC bundle (cube) will be discussed in detail.     

Drying of Dielectric Resin Coatings in the Presence of Polycondensation

Drying of dielectric resin coatings is accompanied simultaneously by evaporation of multicomponent solvents and polycondensation from monomers. The characteristic of the drying is studied experimentally. As a test sample, a vanish consisting of trimellitic acid anhydride and 4.4¹-diphenylmethane diisocyanate dissolved in the mixture of N-methylpyrrolidone and xylene is coated on an aluminum pan. The sample is subjected in drying in two types of dryers: hot air heating and radiation heating. The constant drying rate period is not observed in any run. The maximum drying rate of the sample is lower than the evaporation rate from the solvent layer with no resin. There are remarkable fluctuations in the drying rate in the decreasing drying rate period. The fluctuations are caused by bubble formation. The progress of the reaction can be followed by IR spectroscopic analysis. From these results it is suggested that removal of the solvent and the product is inhibited by the formation of a polymer skin on the surface and it makes control of drying difficult.     

用RHEED方法分析半导体薄膜特性

在讨论ＲＨＥＥＤ原理的基础上，介绍了组建的ＲＨＥＥＤ和其附属的真空系统，并用此装置得到了Ｓｉ薄膜的ＲＨＥＥＤ衍射花样。本文还对实验条件和实验结果进行了简单的分析和介绍。     

Copolymerization of diphenylmethane andp-xylene by oxidative coupling

Summary Diphenylmethane underwent oxidative coupling in the presence of di-t-butyl peroxide and formed 1,1,2,2-tetraphenylethane. This coupling reaction resulted in the formation of a copolymer of diphenylmethane andp-xylene. The new copolymer was soluble in common organic solvents and had a molecular weight of 32,000 (polystyrene base).On leave from Cosmo Oil Co., Japan, under a contract with the Japan International Cooperation Agency     

Global distribution of radionuclides (137Cs and 40K) in marine mammals

Concentrations of anthropogenic radionuclides were measured in the muscle of marine mammals collected from various locations all over the world, and the global distribution of 137Cs in marine mammals was investigated. 40K was detected in all the specimens of marine mammals with no apparent difference between regions. An anthropogenic radionuclide, 137Cs, was detected in most of the species of marine mammals. With regard to the worldwide distribution of 137Cs, the highest concentration was noticed in the U.K. coast, followed by Lake Baikal, and decreases toward the southern sampling points. A strong positive correlation was observed between 137Cs levels in the muscle of marine mammals and the ambient seawater. Marine mammals feeding on fishes showed a higher concentration factor (CF) for 137Cs than those feeding on cephalopods. To our knowledge, this is the first report on the global distribution of 137Cs and the effect of feeding habits on the CF values of 137Cs in marine mammals.     

Isolation and characterization of Bacillus sp. INT005 accumulating polyhydroxyalkanoate (PHA) from gas field soil

A gram-positive bacterium (designated strain INT005) that accumulated polyhydroxyalkanoate (PHA) was isolated from gas field soil. From its morphological and physiological properties and the partial nucleotide sequence (about 500 bp) of its 16S rDNA, it was suggested that strain INT005 was similar to several species of the genus Bacillus. We confirmed that strain INT005 is a Bacillus sp. The PHA productivities of strain INT005 were higher than those of Bacillus megaterium and Ralstonia eutropha at 37-45 degrees C reported to date, and it was suggested that the PHA synthase of INT005 may exhibit moderate thermostability. The bacterium had the ability to produce poly(3-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-4-hydroxybutyrate-co-3-hydroxyhexanoate), and poly(3-hydroxybutyrate-co-6-hydroxyhexanoate-co-3-hydroxyhexanoate) from the appropriate carbon sources. The PHA synthase from INT005 showed similar substrate specificity to those of class I and III PHA synthases and strain INT005 produced PHAs with various monomer compositions. From the analysis of monomer composition and PHA accumulation in the presence of acrylic acid, it was suggested that de novo fatty acid synthesis and beta-oxidation are involved in the PHA synthesis of Bacillus sp. INT005. Since Bacillus sp. INT005 could synthesize PHA even at 45 degrees C and PHAs with various monomer compositions, and only one report on the cloning of the synthesis-related genes from a Bacillus species (B. megaterium) has been published;Bacillus sp. INT005 is thought to be very valuable source of PHA synthesis-related genes.