STABILITY TEST OF SRC II DISTILLATES BY ESR

ABSTRACT

The stability of distillates derived from the SRC II coal liquefaction process has been investigated by means of electron spin resonance (e.s.r.). The samples were prepared by storing at room temperature for 8 days in air or in vacuo. The lighter fraction of distillate deteriorated more easily via oxidation than the heavier fraction.     

High‐pressure short time behavior of traction fluids

The squeeze film formation ability of traction fluids is studied under impact load by dropping a steel ball‐bearing against a flat anvil made of mild steel. The effect of the pressure–viscosity coefficient and of the viscosity is investigated for plastic impact. The depth difference between the lubricated surface dent and the dry dent increases linearly with the product αη of the pressure–viscosity coefficient α and the viscosity η. The importance of the lubricant parameter αη is observed under the squeeze film formation ability from contact voltage or elastohydrodynamic lubrication central film thickness measurement at rolling condition. The intensity of each impact collision is measured by means of an acoustic emission (AE) sensor. The high‐pressure short‐time solidification of traction fluids was confirmed by dent analysis after the impact tests and AE analysis under impact loads. Copyright © 2006 John Wiley & Sons, Ltd.     

Distribution, characteristics, and worldwide inventory of dioxins in kaolin ball clays

Distribution, characteristics, and global inventory of dioxins (polychlorinated dibenzo-p-dioxins [PCDDs] and dibenzofurans [PCDFs] and dioxin like polychlorinated biphenyls) in kaolin clays collected from 10 countries were investigated. Dioxins were found in all kaolin clay samples analyzed, at total concentrations ranging from 1.2 pg/g (Brazil) to 520,000 pg/g (USA). Dioxin concentrations in kaolin clays from a few countries (e.g., Brazil and UK) were lower than those reported for background soils in Japan. Dioxin profiles in kaolin clays were characterized by the domination of the congener octachlorodibenzo-p-dioxin (OCDD), and the concentrations of other congeners decreased in the order of reduction in the levels of chlorination. Furthermore, specific distribution of congeners, with predominant proportions of 1,4,6,9-substituted PCDDs within each homologue group, was found in most clay samples. The ratios of concentrations of PCDD to PCDF and 1,2,3,7,8,9-HxCDD to 1,2,3,6,7,8-HxCDD indicated differences in the profiles found for anthropogenic sources (including pentachlorophenol) and kaolin clays. Concentrations of PCDD/Fs in kaolin clays, except for American ball clays, did not exceed the environmental criteria set by the Law Concerning Special Measures against Dioxins in Japan. Based on the average concentrations measured in our study, inventories of PCDD/Fs from the production/usage of ball clays on a global scale were estimated to be 650 kg/yr; the corresponding value on a TEQ basis is 2400 g-TEQ/yr. More than 480 kg of OCDD is estimated to be released annually from the production of kaolin clays worldwide, suggesting that kaolin clays can be a major contributor for additional source of dioxins, especially OCDD, in the environment.     

A survey of perfluorooctane sulfonate and related perfluorinated organic compounds in water,fish, birds,and humans from Japan

Occurrence of perfluorooctane sulfonate (PFOS) in the tissues of humans and wildlife is well documented. In this study, concentrations and distribution of PFOS, perfluorohexane sulfonate (PFHS), and perfluorobutane sulfonate (PFBS) were determined in samples of surface water, fish and bird blood and livers, and human blood collected in Japan. Notable concentrations of PFOS were found in surface water and fish from Tokyo Bay. PFOS was found in all of the 78 samples of fish blood and liver analyzed. Based on the concentrations of PFOS in water and in fish livers, bioconcentration factors were calculated to range from 274 to 41 600. Concentrations of PFOS in the blood of Japanese human volunteers ranged from 2.4 to 14 ng/mL. PFHS was detected in 33% of the fishes analyzed, at concentrations severalfold less than those of PFOS.     

The dependence of structure and conductivity in three-dimensional phosphate ionic conductors on composition

Two series of solid solutions, Na _x Ca_(1−x)/2Zr₂(PO₄)₃ (NCZP(x), 0⩽x⩽1) and Na _x Nb_1-x Zr_1+x (PO₄)₃(NNZP(x), 0⩽x⩽1), were synthesized. They were examined by powder X-ray diffraction, infra-red (i.r.) absorption and Raman scattering. Ionic conductivities of graphite coated samples were measured. A complete series of solid solutions was formed for NCZP(x), while a second phase was found forx<0.1 for NNZP(x). The i.r. and Raman spectra of their solid solutions consistently showed the formation of PO₄ tetrahedra with different geometries. The composition dependence of conductivity is interpreted on the basis of a structural change around Na⁺.     

Investigations on welding residual stresses in penetration nozzles by means of 3D thermal elastic plastic FEM and experiment

Recent discoveries of stress corrosion cracking (SCC) in weldments including penetration nozzles at pressurized water reactors (PWRs) and boiling water reactors (BWRs) have raised concerns about safety and integrity of plant components. It is well known that welding residual stress is an important factor resulting in SCC in weldments. In the present work, both experimental method and numerical simulation technology are used to investigate the characteristics of welding residual stress distribution in penetration nozzles welded by multi-pass J-groove joint. An experimental mock-up is fabricated to measure welding residual stress at first. In the experiment, each weld pass is performed using a semi-circle balanced welding procedure. Then, a corresponding finite element models with considering moving heat source, deposition sequence, inter-pass temperature, temperature-dependent thermal and mechanical properties, strain hardening and annealing effect is developed to simulate welding temperature and residual stress fields. The simulation results predicted by the 3D model are generally in good agreement with the measurements. Meanwhile, to clarify the influence of deposition sequence on the welding residual stress, the welding residual stress field in the same geometrical model induced by a continuous welding procedure is also calculated. Finally, the influence of a joint oblique angle on welding residual stress is investigated numerically. The numerical results suggest that both deposition sequence and oblique angles have effect on welding residual stress distribution.     

An imbalance between Th1 and Th2-like cytokines in patients with autoimmune diseases--differential diagnosis between Th1 dominant autoimmune diseases and Th2 dominant autoimmune diseases

An imbalance between T helper cell (Th)1 and Th2-like cytokines has been described in several autoimmune diseases. Organ specific autoimmune diseases such as multiple sclerosis (MS) and inflammatory bowel diseases (IBD) are caused by Th1 dominant immune responses. On the contrary, systemic autoimmune diseases such as systemic lupus erythematosus (SLE) and Sj?gren's syndrome(SS) are characterized by Th2 dominant imbalance of cytokine production. It might be useful for differential diagnosis among patients with various autoimmune diseases such as SLE, SS, IBD, and MS to measure the serum levels of cytokines such as IL-10, IFN gamma, and TNF alpha using ultrasensitive enzyme-linked immunosorbent assay system.     

Barium Titanate Ceramics with High Piezoelectricity Fabricated from Fibrous Particles

Barium titanate ceramics with high degrees of c-axis orientation were fabricated from fibrous particles. The maximum piezoelectric constant, d₃₃, obtained was ≅270 pC/N, which is much higher than values reported previously.     

Clinical experience of Rotablator

26 patients (27 lesions) who had severe calcified and diffuse lesions underwent Rotablator treatment, lesion characteristics were type B2, Type C of AHA/ACC classification. There were no patients who had type A1, type B1 lesions. Procedural success rate is 96%, coronary perforation occurred in one patient but not necessary for surgical treatment. Non Q myocardial infarction occurred only in one patient. Follow up Angioplasty were performed 1 and 3 months later after procedures. There were no restenosis after 1 month, but after 3 months, 56% of patients had restenosis.