High reliability of 1.5 ?m two-step VPE-LPE-grown DC-PBH lasers

The reliability of 1.5 ?m InGaAsP/InP DC-PBH lasers prepared by two-step hydride VPE and LPE was estimated at the 70°C, 5 mW constant-power mode. The low degradation rate (8×10?5/h) indicated high reliability of the two-step VPE-LPE-grown LDs with the VPE-grown active layer.     

Transcatheter occlusion of patent ductus arteriosus with a new detachable coil system (DuctOcclud): a multicenter clinical trial

A comparison of two methods: analytical and calculation on an estimation of dietary intakes of nitrate and nitrite from six different types of general hospital diets was studied. Studies were performed in the winter season of 1996-1997. It was found that the mean daily intake of nitrates was 85 mg per person in the analytical method, and 65 mg per person in the calculated method. The estimation of average dietary intakes of nitrite was adequate: 1.67 mg per person (the analytical method) and 1.18 mg per person (the calculated method). The main source of nitrates were vegetables, whereas the main source of nitrites was meat and meat-containing products. We suggest that the different methodologies, analytical and calculation methods, for measuring dietary intakes of nitrate and nitrite from diets make it possible to make direct comparisons of intakes.     

Surface potential on LDPE and PP films after removal of the upperdisk electrode

The potential distribution was measured on the free surface of low-density polyethylene (LDPE) and polypropylene (PP) films which had been inserted between plane electrodes after the removal of the upper brass disk electrode. The polarity of the surface potential was always the same as that of the applied step voltage which had been subjected to the upper electrode for a while and then shorted. The absolute value of the surface potential tended to increase to a constant value of ~650 V with increasing applied voltage and application time for both polarities. There was no appreciable difference in the surface potential between PP and LDPE when the applied voltage and its application time changed. However, the increase in the shortcircuit time tended to increase the surface potential for LDPE only, while it did not change that for PP. The effect of a longer shortcircuit on the surface potential increase for the LDPE films for both polarities could be explained by bipolar injection     

Study of hyper-interfacial bonding of ultrafine-grained steels

To obtain so-called super-steels providing a good combination of high strength and high toughness, efforts are being made to develop ultrafine-grained steels involving intense grain size refinement with retention of a mild steel-equivalent low-alloy composition in order to lessen their environmental impact and reduce total life cycle costs.^1-5 Within this context, it is imperative to develop suitable welding and joining technologies for structural applications of ultrafine-grained steels; a number of previous studies have addressed their welding characteristics.^6-8 Developed ultrafine-grained steels, however, face a number of important problems such as grain coarsening, HAZ softening and microstructural changes due to the thermal effect of the welding process itself. Such microstructural changes are predicted to exert a significant effect on joint characteristics, particularly deterioration of welded joint performance in ultrafinegrained steels as steels subjected to a high degree of grain size control. Microstructural changes in the joints of ultrafine-grained steels, however, have not yet been satisfactorily investigated.     

Preparation of Fe-Al Binary System Intermetallic Compounds by Multi-Layered Roll-Bonding

Iron aluminides exhibit good resistance to high-temperature sulfidizing and oxidizing environments and potential for structural applications at high temperatures under corrosive environments. In this study, Fe-Al intermetallic compound was prepared by multi-layered roll-bonding of elemental Fe and Al foils. The process consisted of the accumulative roll-bonding (ARB) for making a laminated Fe/Al sheet and the subsequent heat treatment promoting a solid phase reaction in the laminated Fe/Al sheet. The microstructures produced at each processing stage were characterized by optical microscopy and scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS). Vickers microhardness testing was used for hardness determination. A homogeneous intermetallic compound of Fe3Al or FeAl could be obtained after the subsequent heat treatment for 1.8 ks at 973 K and for 10.8 ks at 1123 or 1173 K.     

Analytical and numerical study of the effects of an elastically-linked body on sloshing

In order to investigate the effects of an elastically-linked moving body on liquid sloshing inside a tank, an analytical formulation and a numerical approach were proposed to assess hydrodynamic loads in a partially filled rectangular tank with a body connected to the tank by springs. The analytical approach was developed based on the potential theory to calculate fluid velocity field, and the dynamics of the liquid sloshing coupled to the moving body are described as a mechanical system with two degrees of freedom. The coupling between the fluid and the moving body is given by a damping force calculated based on the body geometry and the fluid velocity field. The proposed numerical approach is based on the Moving Particle Semi-implicit (MPS) method, which is a Lagrangian particle-based method and very effective to model nonlinear hydrodynamics due to fluid–structure interaction. In the numerical approach, the rigid body is modeled as a cluster of particles and the motions are calculated considering its mass, moment of inertia, hydrodynamic loads and springs restoring forces. The elastic link between the body and tank is modeled by applying Hooke’s law. Simple cases of floating body motion were used to validate the numerical method. Finally, analytical and numerical results were compared. Despite its simplicity, the analytical approach proposed in the present work is an efficient approach to provide qualitative understanding and a first estimate of the moving body effects on the sloshing inside the tank. On the other hand, the numerical approach can provide more detailed information about the coupling phenomena, and it is an effective mean for the assessment of the reduction of the sloshing loads due to the moving body with elastic link. Finally, the effectiveness of the concept as a sloshing suppressing device is also investigated.     

Immunostimulatory effects of water extract from bulbus arteriosus in tuna in vitro

Immunostimulating effects of water extract from bulbus arteriosus in tuna were examined and found to enhance IgM production by human hybridoma HB4C5 cells. When tuna bulbus arteriosus extract was heated, the IgM production-stimulating activity was decreased or lost. To identify the active substance, the extract was partially purified by anion-exchange chromatography, and proteins contained in positive fractions were analyzed by LC-MS/MS. The positive fractions contained lactate dehydrogenase, triosephosphate isomerase, enolase, and haemoglobin. Each of these four proteins was verified to enhance IgM production by HB4C5 cells with the commercially available purified proteins, suggesting that all of these four proteins are active substances in the extract. The immunostimulatory effect of these proteins was also examined on mouse primary spleen lymphocytes in vitro. Lactate dehydrogenase enhanced IgA, IgG, and IgM production and triosephosphate isomerase enhanced IgA and IgG production. In particular, lactate dehydrogenase had the strongest Ig production-stimulating effect on HB4C5 cells and on mouse primary lymphocytes. Thus, fish viscera may serve as an important raw material for the enhancement of the acquired immune system, once processed.     

Acceleration of Metastable to Alpha Transformation of Al2O3 Scale on Fe?CAl Alloy by Pure-Metal Coatings at 900???C

The effect of pure-metal coatings on the transformation of a pre-formed ??-Al₂O₃ scale on an Fe?C50Al alloy was investigated. The elements Fe, Cr, Ti, and Ni were deposited on the pre-formed Al₂O₃ having a thickness of about 50?nm. Ti, Cr or Fe coatings on pre-formed ??-Al₂O₃ were found to accelerate the transformation to ??-Al₂O₃, while no apparent effect was observed from the Ni coating. Since the corundum crystal structure of Ti₂O₃, Cr₂O₃ and Fe₂O₃ was indentified on Ti, Cr or Fe coated samples and the transformation to ??-Al₂O₃ started at the outer part of the ??-Al₂O₃ scale, these corundum oxides were considered to act as heterogeneous nucleation sites for ??-Al₂O₃, therefore promoting the transformation from ??-Al₂O₃ to ??-Al₂O₃. The growth rate of ??-Al₂O₃ grains and the rate of advance of the ??-Al₂O₃/??-Al₂O₃ interface were found to be faster with the Fe coating.     

Local buckling restraint condition for core plates in buckling restrained braces

Buckling Restrained Braces (BRBs) are commonly used as bracing elements in seismic zones. A key limit state governing BRB design is to prevent flexural buckling. However, when the wall thickness of the steel tube restrainer is relatively small compared to the cross-section of the core plate, the restraint conditions against the local buckling of the core plate can be critical for the stability and strength of the BRB. In this study, cyclic loading tests and numerical analyses of BRBs were carried out using various tube restrainer configurations to investigate the influence of local buckling of the restrainer on BRB strength and ductility.