Aisan (Japan)

In the semi-solid high-pressure die casting process, the slurry flows as a solid-liquid two-phase flow. In this study, the effect of the shape of solid particles on their distribution in the slurry was investigated. The solid particles were concentrated in the center of the flow direction in the case of globular-shaped solid particles and high-flow-velocity conditions. Moreover, the concentration ratio of the solid particles increased with an increasing Reynolds number. This phenomenon was explained as follows. The shape of the solid particles affected the viscosity of the slurry; the viscosity was decreased by the globular particles. The solid particles applied Saffman force, which is generated by the velocity gradient, and moved in the direction away from the solid-liquid interface. The Reynolds number increased with decreasing viscosity or increasing flow velocity; therefore, the Saffman force increased with an increasing Reynolds number.

The myeloproliferative neoplasms (MNPs) are characterized by accumulation of erythrocytes, leukocytes and platelets morphologically normal and their precursors. In recent years several studies have sought to understand the cellular and molecular mechanisms involved in the pathophysiology and progression of these disorders in order to find diagnostic and prognostic markers and effective therapies. The point mutation in the gene encoding the enzyme Janus kinase 2 (JAK2 V617F), present in approximately 90% of PV patients and in 50% of patients with ET and MF was the main abnormal genetic finding associated with these diseases. This mutation results in constitutive activation of JAK2 enzyme and the deregulation of cell proliferation and resistance to apoptosis. Our research group described in PV, ET and MF altered expression of apoptosis regulatory genes and literature data suggest that deregulation of the cell cycle contributes to the pathophysiology of MNPs. In this project the aim was to investigate the signaling pathway of the association m-TOR with the changes of the cell cycle and JAK / STAT in NMPs. The signaling pathway participates in the m-TOR cell survival and proliferation processes. The experimental strategy was to evaluate the expression of genes and proteins, regulators of m-TOR pathway in leukocytes from patients with and NPMC cell lines treated with the JAK2 JAK2 + and AKT inhibitors. To determine the relationship of m-TOR pathway with MNPs has been selected the eIF4E gene deregulated in these disorders to observe their modulation in pharmacologically inhibited cells lines JAK 2 positive. Results of this study contribute to the description of new therapeutic targets of dependent and independent JAK2 kinase activity and to a better understanding of the signaling pathway of participation m-TOR in the pathophysiology of NMPs.

Rotaing bending and axial fatigue tests have been performed using solution treated and aged materials in two beta titanium alloys, Ti-15Mo-5Zr-3Al and Ti-22V-4Al alloy. Subsurface crack initiation was found to be a microstrructure and a stress ratio related phenomenon. In the former alloy, cracks were initiated internally only in a material that was solution treated above the beta transus and at a certain stress ratio in relatively short life regime. The effects of grain size and mean stress were not characterized entirely by the Hall-Petch relationship and the Goodman relationship, respectively, which was attributed to different crack initiation mechanisms. In the latter alloy, subsurface crack initiation was also seen in the long life regime around or above 10^7 cycles, resulting in a step-wise S-N curve. A smooth facet invariably existed at the crack initiation site. The occurrence of this mode of failure is discussed based on microstructural and mechanical considerations.

The Geographical Survey Institute (GSI) constructed the new geodetic datum of Japan, “Japanese Geodetic Datum 2000 (JGD2000) ”. The coordinates of the old geodetic datum of Japan, “Tokyo Datum (TD) ”, should be replaced by JGD2000. This report proposes precise and minimum bias transformation for the public and cadastral survey networks. Least squares collocation method is used for the precise transformation. To minimize a network bias, the transformation parameters are calculated over a small area every year. The transformation keeps the network configuration constant.“TKY2JGD”software is published by GSI to transform the coordinates from TD to JGD2000. This report also proposes that transformation distortion of the TKY2JGD can be estimated by applying the strain theory. The distortion of transformed coordinates is expressed by angle and scale changes. The angle and scale changes correspond to the maximum shear strain and dilatation respectively.

<div class="htmlview paragraph">A direct injection spark ignition (DISI) gasoline engine with a new stratified charge combustion concept has been launched on the Japanese domestic market. This new concept consists of two components. First, a thin fan-shaped spray from a slit nozzle enables wide spray dispersion, moderate spray penetration and a fine atomization. Second, a shell-shaped piston cavity allows better mixture formation, however avoiding distinct charge motions (such as tumble or swirl). Simple intake port geometry increases the full load performance. The combustion concept, at the same time allows stratified charge to be used at higher load and at higher engine speeds and improves the homogeneous charge combustion. A new 3L in-line 6 gasoline engine with this combustion concept showed 20% better fuel economy than a 3L port fuel injection (PFI) engine (λ=1 feed back system) under the Japanese 10-15 mode.</div>

A Langevin-type ultrasonic vibrator works as an ultrasonic motor when it is pressed slant wise against the surface of an object. This paper describes a robot hand with three fingers that each works as an ultrasonic motor. This robot hand can simultaneously grasp a cylindrical body and rotate the body about its axis. The authors propose a PWM (pulse width modulation) method for controlling the speed of ultrasonic motors by changing the duty ratio of the voltage applied to the motors. The vibration of the ultrasonic motor and the driving characteristics of a robot hand were examined experimentally. It was confirmed that the vibration speed of the tip of the ultrasonic motor wets approximately proportional to the duty ratio of the applied voltage. The velocity of the motor increases with an increase in duty ratio, except for the offset region. The torque characteristic curves approach the point of origin, moving parallel as the duty ratio decreases.

クリストバライトのカーボンによる還元窒化反応を1360°-1475℃で行った. 反応生成物はα-Si3N4とβ-Si3N4で, わずかにSiCも認められた. Si3N4(α+β)中のα-Si3N4の生成割合は約90%で, Fe2O3 (0.18wt%) の添加により約95%に増加した. 窒化反応生成物は主として1μm程度の丸味を帯びた粒子からなるが柱状及び針状粒子も認められた. SiO2のSi3N4への初期転化率から求めた反応の活性化エネルギーは約150kcal/molで, Fe2O3を添加すると135kcal/molに低下した. SiO2-C-N2系の窒化は生成経路I-IIIによると考察した. すなわち, IはSiO2(s) とC(s) の反応でSi(s, l) が生成し, このSi(s, l) が窒化される. IIはSiO2(s) とC(s) あるいはCO(g) の反応により, SiO(g) が生成し, このSiO(g) が不均化によりSi(s, l) とSiO2(s) を生成する. このSi(s, l) が窒化される. IIIはSiC(s) とN2(g) の反応でSi3N4(s) を生成する. 本実験ではIが主な生成経路と考えられる. IIIはSiCの生成量が少ないので, 全窒化反応の中で重要な生成経路とならないと考える. Fe2O3を添加したSiO2-C-N2系での窒化では, Fe-Si系の液相を経由して進行する可能性がある.