Evaluation of inelastic constitutive models under plasticity-creep interaction for steel at 600°C

Uniaxial tests to identify plasticity-creep interaction in steel at 600°C were carried out as the Benchmark Project by the Subcommittee on Inelastic Analysis and Life Prediction, JSMS. The purpose of this paper is to present recent experimental data and predictions of constitutive models obtained in the project. Ten types of constitutive models were utilized to compare analytical predictions to sixteen benchmark experiments which are grouped into four categories: (I) tensile and creep tests under monotonic loading, (II) mixed mode tests under plastic and creep loading, (III) ratcheting deformation tests under program loads, and (IV) cyclic deformation tests under the combination of different strain rates. The benchmark tests in Group IV are used to estimate the creep-fatigue life of steel; the results will be published in a separate paper.     

An analysis of slow phase velocity on congenital nystagmus-asymmetrical responses of optokinetic stimulation

Persistence of the hypoglossal artery is an unusual congenital abnormality of the carotid arterial system, and the simultaneous occurrence of atheromatous disease in the internal carotid artery and persistent hypoglossal artery is even more uncommon. Carotid surgery in this situation is challenging, and the surgeon must be aware of potential inherent pitfalls. A 74-year-old woman with asymptomatic stenosis of both internal carotid and hypoglossal arteries associated with occlusion of the contralateral internal carotid artery underwent successful revascularization. The anatomy of this unusual lesion and the surgical strategies, which included cranial nerve dissection and mandibular subluxation, are reviewed.     

Hot-carrier-injected oxide region in front and back interfaces inultra-thin (50 nm), fully depleted, deep-submicron NMOS andPMOSFET's/SIMOX and their hot-carrier immunity

The hot-carrier-injected oxide region in the front and back interfaces is systematically clarified for fully depleted surface-channel nMOSFET's and surface-channel and buried-channel pMOSFET's fabricated on an ultra-thin (50 nm)-film SIMOX wafer. Based on these results, the influence of these injected carriers on front-channel properties is investigated. NMOSFET degradation is shown to be caused by hot-carriers injected into the drain side of the front oxide and pMOSFET degradation by hot-electrons injected into the drain side of both the front oxide and the back oxide. Additionally, it is shown experimentally that these fully depleted devices with effective channel lengths between 0.1-0.2 μm have fairly high hot-carrier immunity, even for single-drain structures     

Micro-computerized tomographic observation of the spinning apparatus in Bombyx mori silkworms

Silkworms and spiders have evolved complex spinning apparatus thought to use highly controlled conditions to optimize protein folding and crystallization to provide a tough fiber. Accordingly, the structure and function of the natural spinning apparatus has been studied with great attention as an interesting piece of biological engineering with potential for mimicry in an industrial process. However it is still not well understood. Here we used Micro-Computerized Tomographic equipment (mCT) to visualize the three-dimensional structure of the spinning apparatus in Bombyx mori silkworms. Multidirectional tomograms obtained by X-ray radioscopy provided valuable information on the detailed arrangement of each muscle of the silk press. It is suggested that the duct in the silk press part plays a part as an extrusion die whose cross-sectional area can be controlled by muscles to optimize applied stresses in the partially gelled silk within its lumen.     

Accelerator Analysis of Tributyltin Adsorbed onto the Surface of a Tributyltin Resistant Marine Pseudoalteromonas sp. Cell

Tributyltin (TBT) released into seawater from ship hulls is a stable marine pollutant and obviously remains in marine environments. We isolated a TBT resistant marine Pseudoalteromonas sp. TBT1 from sediment of a ship’s ballast water. The isolate (10^{9.3 ± 0.2} colony-forming units mL⁻¹) adsorbed TBT in proportion to the concentrations of TBTCl externally added up to 3 mM, where the number of TBT adsorbed by a single cell was estimated to be 10^8.2. The value was reduced to about one-fifth when the lysozyme-treated cells were used. The surface of ethanol treated cells became rough, but the capacity of TBT adsorption was the same as that for native cells. These results indicate that the function of the cell surface, rather than that structure, plays an important role to the adsorption of TBT. The adsorption state of TBT seems to be multi-layer when the number of more than 10^6.8 TBT molecules is adsorbed by a single cell.     

Autonomic nervous function of the patients with neurally mediated syncope

Although diagnosis of neurally mediated syncope (NMS) using head-up tilt (HUT) test has been established, the exact mechanism of NMS has not yet been elucidated. We evaluated beta and alpha-adrenergic function in NMS patients by pharmacological autonomic function test. The alpha-adrenergic sensitivity of NMS patients was significantly lower than that of control subjects. The patients who need low dose isoproterenol for provocation of syncope showed higher beta-adrenergic sensitivity than patients who developed syncope without isoproterenol. Thus, pharmacological autonomic function test was useful for evaluation of NMS patients.     

Characterization of cytochrome P450 (CYP3A12) induction by rifampicin in dog liver

We investigated the mechanisms of renal vascular wall thickening in a rat model of N-nitro L-arginine methyl ester (L-NAME)-induced hypertension. To separate the effects of L-NAME-induced hypertension from other effects of nitric oxide (NO) inhibition, we created two models of L-NAME-induced hypertension: both had the same blood pressure level but NO inhibition was moderate in one group (group M) and severe in the other (group S). Urinary excretion of nitrates and nitrites was lower in group S than in group M. Wall thickening and lipid deposition in renal vessels were significantly greater in group S than in groups M. Simple and multiple regression analyses indicated that renal vascular wall thickening was more strongly correlated with lipid deposition than with blood pressure. The number of vessels positive for staining with Sudan black B was negatively correlated with urinary NO excretion. Expression of fibronectin and transforming growth factor-beta was greater in the Sudan black B-positive than in the Sudan black B-negative vessels, suggesting that extracellular matrix production was increased in vessels with lipid deposition. Lipid deposition and increased production of extracellular matrix may contribute to renal vascular wall thickening in L-NAME-induced hypertension. Some mechanisms independent of hypertension play important roles in vascular wall thickening induced by NO inhibition.     

A sequencing problem for a mixed-model assembly line in a JIT production system

In an assembly line of a just-in-time (JIT) production system, workers have the power and the responsibility to stop the line when they fail to complete their operations within their work zones. This paper deals with a sequencing problem for the mixed-model assembly conveyor line in the JIT production system. In some environment, the most important criterion is the line stoppage rather than the variation of production rates. The problem is to find an optimal sequence of units that minimizes the total line stoppage time. Lower and upper bounds of the total line stoppage time are derived and the branch-and-bound method is applied to the problem. A numerical example is given.