X-ray study of hydrogenated jojoba wax

Crystallographic analysis of hydrogenated jojoba wax ester shows the crystal structure to be monoclinic with orthorhombic perpendicular, 0⊥, chain packing. Cell dimensions are: a=4.99, b=7.44, c=55.2Å, β=90°. A larger secondary unit cell is observed and identified as permitting the hydrocarbon ester chains freedom of rotation. Hydrogenated jojoba was ester is crystallographically similar to polyethylene.     

A study of composite foams for diving suits subjected to high hydrostatic pressure

In order to obtain foams possessing flexibility and at the same time heat insulation under high hydrostatic pressure, composite foams with spherical rigid foams filled in flexible rubber foam at certain intervals were prepared and their thermal conductivity and flexural rigidity were studied. The following points were found: (1) With a unit model having a spherical rigid foam in the middle, the thermal conduction of a composite foam was analyzed under the conditions of steady one-dimensional heat flow. Theoretical equations giving overall coefficients of heat transmission under atmospheric and hydrostatic pressures were obtained, and the adequacy of these theoretical equations was confirmed by the measurement of overall coefficients of heat transmission of composite foams in an apparatus so constructed as to allow heat conduction experiments under pressures ranging from atmospheric to the hydrostatic pressure corresponding to 100-m depth in water. (2) The effect of the filled spherical rigid foams on heat insulation is notable under hydrostatic pressures corresponding to a 20-m depth or more in water. Under the hydrostatic pressure corresponding to a 100-m depth in water, the coefficient of heat insulation of the most closely filled composite foam used in the experiment was approximately 35% larger than that of the unfilled foam, while the theoretical most closely filled composite foam gives an approximately 110% increase. (3) Under the hydrostatic pressure corresponding to a 100-m depth in water, the flexural rigidity of the most closely filled composite foam used in the experiment was approximately one half that of an unfilled foam of the same heat insulating property.     

Polymerization of hexachlorocyclotriphosphazene by sulphur and selenium

The thermal bulk polymerization of hexachlorocyclotriphosphazine is described. The possibility of obtaining soluble polymer using sulphur and selenium as catalysts was investigated. It was found that the catalytic activity of selenium was much lower than that of sulphur. Monomeric sulphur may be acting as a chlorine-attractive agent for hexachlorocyclotriphosphazine.     

Polyacetylene film: A new electrode material for photoenergy conversion

Polyacetylene films were characterized as an electrode material in aqueous solutions. The trans polyacetylene films behaved as electrodes under reducing conditions. Oxygen gas evolution was greatly retarded under oxidizing conditions, primarily due to the high reactivity with oxygen. Visible light illumination resulted in a positive shift in electrode potential. The electrode developed photopotential reversibly in accord with illumination. The polyacetylene electrode gave cathodic photocurrent when contacted with a deoxygenated acetate buffer. The cathodic photocurrent increased with decreasing pH, ranging from 0 to 5.5 × 10^?6 A/cm². The possible use of polyacetylene electrodes for photoenergy conversion is discussed.     

Seawater desalting by electrodialysis

A 120 M³/day electrodialysis plant for municipal seawater desalting was constructed by Asahi Chemical Industry Co., Ltd. for the city of Hofu, Japan, with operation beginning in September, 1974. The performance and maintenance for the first year of operation is discussed. The fully automatic system is inspected once per week by an operator and is serviced twice per year. Membrane replacement after 16 months of operation is less than one percent. Desalacion del agua de mar por electrodialisis     

Polymerizations of α-olefins and styrene with MgCl2-supported titanium catalyst system: MgCl2/TiCl4/PhCO2Et with AlEt3PhCO2Et

Summary Kinetic analysis was performed in a short time polymerizations of 1-butene,4-methyl-1-pentene and styrene by using a catalyst system composed of MgCl₂/TiCl₄/PhCO₂Et with AlEt₃/PhCO₂Et which is known as a highly active and highly stereospecific catalyst system in olefin polymerization. The concentration of the active centers, [C ^*], the propagation rate constant, k _p, and the chain transfer rate, r _tr, were determined for each monomer. It was found that the values of [C ^*] were almost same for every monomer, but the values of k _p changes widely in the following order: propylene>1-butene>4-methyl-1-pentene>styrene.     

烧结钢的应力-弹性及塑性应变曲线的制作与评价

根据拉伸试验(TT)得到的应力-应变曲线和通过声音脉冲方法(APM)得到的声速,计算并比较了烧结钢的弹性模量(E)和泊松比(v).Err和vTT的值分别小于EAPM和vAPM,这是因为在烧结钢的应力-应变中不仅包含了弹性应变,而且也包含了塑性应变.利用由EAPM和vAPM的值计算得到的纵向和横向弹性应变,从纵向和横向应力-应变中分离出纵向和横向的塑性应变.在小应变时烧结钢没有显示线性应力-应变的情况下,可以很简单地由纵向塑性应力表中求出弹性极限或0.2%的屈服强度.对于同样的应力,每个样品的弹性应变和塑性应变的不同,可以由基于孔隙特征(孔隙的大小、形状、相互连接及微观结构的不同)的模型来解释.     

Statistical data analyses to elucidate the causes and improve the countermeasures for preventing train accidents in Japan

We investigate train accident data in Japan to elucidate the causes and improve the countermeasures for reducing the number of train accidents. We deal with statistical data on train accidents in the last 15 years, including frequency, types such as derailment and crash, causes and consequences. We review the historical trend of train accidents by applying a statistical modeling approach dealing with both serious accident data and total number of accidents. Probability distributions for explaining this train accident data are shown. We show the results of quantitative data analyses on the train accidents, that occurred at the ground‐level crossing and the relationship among utility type of railway company, equipment at the crossing and consequences of the accidents. Probabilistic mathematical models are used in the analyses. Finally, we try to evaluate the effectiveness of the countermeasures for preventing train accidents.