Supercooling of Homogeneous Liquid Phase of Liquid Metals and Alloys -Poor Supercooling around the Eutectic Composition of Liquid Ni-Nb System

To study the supercooling of many liquid metals with high melting temperatures, the investigation was performed for the cooling curves of electrostatic levitation (ESL) experiments, which had been originally obtained for the measurements of many physical properties. The largest supercooling over the literature values was found for liquid Ru (428 K), Ta (721 K), W (601 K), and Ir (438 K), where temperatures in the parentheses mean the supercooling of respective liquid metals. This indicates the validity of ESL for the supercooling experiments of liquid metals and alloys because of being rather free from the heterogeneous nucleation. This ESL was applied to the study of supercooling of homogeneous liquid phase in the composition range from 29 at% Nb to 71 at% Nb of eutectic Ni-Nb system, whose eutectic point is present at 40.5 at% Nb and 1448 K. The experimental result shows a poor supercooling tendency of homogeneous liquid phase around the eutectic composition in spite of large supercooling far apart from this eutectic composition. This characteristic feature was discussed based on the classical nucleation theory coupled with the knowledge recently found, the existence of concentration fluctuations in the homogeneous liquid phase near the eutectic point

Identification of Secretory Immunoglobulin A in Human Sweat and Sweat Glands

Secretory immunoglobulin A (sIgA) plays an important role in local immune defense mechanisms. Although skin is always exposed to external antigens, the role of local immune defenses involving sIgA in the skin has not been adequately studied. In order to evaluate the presence of sIgA in sweat, we have measured the concentration of sIgA in human sweat by enzyme immunoassay and have localized the components of sIgA in the sweat glands of human axillary skin. The concentration of sIgA in sweat was found to be 10 times higher in men than in women (13.0 ± 0.9 μg/ml versus 1.6 ± 0.9 μg/ml). Secretory component (SC) was localized immunohistochemically in protein synthetic organelles, such as the perinuclear spaces and Golgi complex, in cytoplasmic vesicles, and along the external surface membranes of mucous cells on the terminal segment of eccrine sweat glands. IgA and J chain were present in plasma cells in the protein synthetic organelles. The luminal aspects of eccrine sweat ducts also strongly express SC, as well as IgA and J chain. Neither SC, IgA, or J chain were identified in epithelial cells of apocrine sweat glands. These findings are consistent with the theory that J chain complexed with dimeric IgA is synthesized in plasma cells and is transported by SC-mediated endocytosis transfer across mucous cells of eccrine sweat glands and thus into sweat

Optimum back-pressure forging using servo die cushion

This study focused on utilizing a servo die cushion (in conjunction with a servo press) as a "back-pressure load generator," to determine its effect on shape accuracy of the formed part and total forming load in forward extrusion during cold forging. The effect of back-pressure load application was confirmed in experiments, and the optimum setting pattern of back-pressure load was considered to minimize both shape accuracy of the formed part and back-pressure energy, which was representative of forming energy using a sequential approximate optimization. The precise back-pressure load control by the servo die cushion enabled the ideal load-pattern setting for optimization to be achieved

Electrostatic Levitation Furnace for the ISS

JAXA (Japan Aerospace Exploration Agency) has just started the development of Electrostatic Levitation Furnace to be launched in 2014 for the ISS. This furnace can control the sample position with electrostatic force and heat it above 2000 degree Celsius using semiconductor laser from four different directions. The announcement of Opportunity will be issued soon for this furnace. In this paper, we will show the specifications of this furnace and also the development schedul

Research and Design of a Routing Protocol in Large-Scale Wireless Sensor Networks

无线传感器网络，作为全球未来十大技术之一，集成了传感器技术、嵌入式计算技术、分布式信息处理和自组织网技术，可实时感知、采集、处理、传输网络分布区域内的各种信息数据，在军事国防、生物医疗、环境监测、抢险救灾、防恐反恐、危险区域远程控制等领域具有十分广阔的应用前景。 本文研究分析了无线传感器网络的已有路由协议，并针对大规模的无线传感器网络设计了一种树状路由协议，它根据节点地址信息来形成路由，从而简化了复杂繁冗的路由表查找和维护，节省了不必要的开销，提高了路由效率，实现了快速有效的数据传输。 为支持此路由协议本文提出了一种自适应动态地址分配算——ADAR（AdaptiveDynamicAddre...As one of the ten high technologies in the future, wireless sensor network, which is the integration of micro-sensors, embedded computing, modern network and Ad Hoc technologies, can apperceive, collect, process and transmit various information data within the region. It can be used in military defense, biomedical, environmental monitoring, disaster relief, counter-terrorism, remote control of haz...学位：工学硕士院系专业：信息科学与技术学院通信工程系_通信与信息系统学号：2332007115216

Hybrid Processing Combining Electrostatic Levitation and Laser Heating: Application to Terrestrial Analogues of Asteroid Materials

Electrostatic levitation combined with laser heating is becoming a mature technique that has been used for several fundamental and applied studies in fluid and materials sciences (synthesis, property determination, solidification studies, atomic dynamic studies, etc.). This is attributable to the numerous processing conditions (containerless, wide heating temperature range, cooling rates, atmospheric compositions, etc.) that levitation and radiative heating offer, as well as to the variety of diagnostics tools that can be used. In this paper, we describe the facility, highlighting the combined advantages of electrostatic levitation and laser processing. The various capabilities of the facility are discussed and are exemplified with the measurements of the density of selected iron-nickel alloys taken over the liquid phase

Effect of an External Electric Field on the Kinetics of Dislocation-Free Growth of Tetragonal Hen Egg White Lysozyme Crystals

Dislocation-free tetragonal hen egg white (HEW) lysozyme crystals were grown from a seed crystal in a cell. The rates of tetragonal HEW lysozyme crystal growth normal to the (110) and (101) faces with and without a 1-MHz external electric field were measured. A decrease in the typical growth rates of the crystal measured under an applied field at 1 MHz was observed, although the overall driving force increased. Assuming that the birth and spread mechanism of two-dimensional nucleation occurs, an increase in the effective surface energy of the step ends was realized in the presence of the electric field, which led to an improvement in the crystal quality of the tetragonal HEW lysozyme crystals. This article also discusses the increase in the effective surface energy of the step ends with respect to the change in the entropy of the solid