Masato Osumi

Enlargement of Poly-Si Film Grain Size by Excimer Laser Annealing and Its Application to High-Performance Poly-Si Thin Film Transistor

By both numerical simulation and experimental investigation, we found it possible to enlarge the grain size (?3000 ?) of polycrystalline silicon (poly-Si) films by excimer laser annealing, using a new method to control the solidification process of molten Si - low-temperature (?400?C) substrate heating during laser annealing. Poly-Si thin-film transistors (TFTs) fabricated by this new excimer laser annealing method showed a high field-effect mobility of 230 cm2/V?s, and good uniformity of field-effect mobility (?10%) within the effective laser irradiation area.

Stress on a reaction vessel by the swelling of a hydrogen absorbing alloy

There is a possibility that hydrogen absorbing alloys will generate unexpected stress in an alloy bed and deform or destroy the vessel because the alloys expand when they absorb hydrogen. The amount of stress generated on the vessel surface by alloy swelling was measured with the object of elongating the life time of the reaction vessel in heat utilization systems that use hydrogen absorbing alloys. As a result, it was found that 1) localized stress is generated at the bottom of the vessel due to hydrogen ab-/desorption cycles with an alloy packing fraction of 50 vol %, and this stress not only increases with each cycle, but also continues to increase even after plastic deformation of the vessel, 2) stress accumulation depends on the amount of hydrogen ab-/desorption and on the initial packing fraction, and 3) the mechanism for stress accumulation can be estimated as a two-step process in which agglomeration between the hydride particles occurs when the packing fraction of hydride is higher than 61 vol % in the initial cycles (Step 1), and then fine powder generated by pulverization during the cycles falls in gaps at the bottom of the vessel and causes the hydride packing fraction at the bottom of the vessel to gradually increase (Step 2).

Development of a skin temperature measuring system for non-contact stress evaluation

Skin temperature is an effective indicator for objectively evaluating human sensations, because it is controlled by sympathetic nerve activity which reflects the course of information processing in the brain. In this paper, the authors show a method to evaluate stress from skin temperature and an equipment which continuously measures skin temperature of an subject working in front of a computer terminal. An experiment is performed to investigate a relationship between stressful task and the skin temperature. The experiment shows that there is a high correlation among stress, skin temperatures on nose and forehead. From this experiment, a regression equation is derived which computes the intensity of stress from skin temperatures on nose and forehead. A non-contact skin temperature measuring system is developed based on knowledge obtained in the experiment. The system comprised of an infrared camera, color camera, image processing unit and workstation. The features are the abilities to track nose and forehead positions of an subject doing computer operation automatically and to evaluate the stress continuously.

Improving the uniformity of poly-Si films using a new excimer laser annealing method for giant-microelectronics

Film uniformity is the main problem when applying laser-recrystallised poly-Si films to thin film transistors (TFTs) in giant micro electronics. However, this has been dramatically improved by a new excimer laser annealing method in which the solidification process of molten Si is controlled by low-temperature (400°C) substrate heating during excimer laser annealing. Poly-Si TFT fabricated around the laser irradiation overlap region exhibited a high field effect mobility uniformity of within ±8%.

Using facial skin temperature to objectively evaluate sensations

Abstract Facial skin temperature enables automatic non-contact measurement, and is valid for objectively evaluating sensations like stress and fatigue because it varies with autonomic nerve activity triggered by the onset of sensations. The present report therefore proposes a method that uses facial skin temperature to infer stress, and outlines the results of evaluations conducted to confirm the validity of the inference formula. At the same time, this report also proposes a formula that infers fatigue through facial skin temperature based on the assumption that fatigue is the result of accumulated stress, and experimental results here suggest that the fatigue inference formula is also valid. Furthermore, color image evaluations using the stress inference formula suggest that the stress inference formula is valid for objectively evaluating color images as well. Relevance to industry The present method can be used to create a system of evaluating sensations through facial skin temperature. The system is useful not only to estimate stress and fatigue of operators in nuclear power plant, but also to evaluate color images.

Experimental studies of the radiative properties of sulfur dioxide

Abstract The narrow band-model parameters S/d, γN/d and B have been obtained experimentally for the infrared bands of SO2. Good agreement was obtained between the present experimental and previous theoretical studies. The revised wide band-model parameters were determined and used to calculate total gas emissivities, which are found to be considerably different from previously published values.

An evacuated glass tube solar collector and its application to a solar cooling, heating and hot water supply system for the hospital in Kinki University

Abstract A solar cooling, heating and hot water supply system for the Hospital with evacuated glass tube type solar collectors was described. Analysis has been made of the evacuated glass tube collector and some results of the calculation were shown. The results of the performance of the solar collectors in the large scale system were shown for one year operation to confirm the results as expected at the time of designing.

Non-contact method for measuring facial skin temperature

Abstract Because facial skin temperature varies with sensations, it is an effective means of objectively evaluating sensations. The present report proposes a method that continuously measures facial skin temperature automatically using color and infrared cameras. With this method, the skin temperature range within an infrared image is superimposed over the skin color range within a color image to produce overlapping areas from which the facial area is extracted. Low-luminosity areas are then extracted from the extracted facial area in order to identify the eyes and eyebrows. Once the eyes and eyebrows are identified, the nose and forehead sections can be identified using their relative positions to the eyes and eyebrows, so now skin temperature for relevant facial areas can be measured from infrared image values. Relevance to the industry The present method can be used to develop systems that evaluate sensations through facial skin temperature without placing stress on test subjects. Accidents caused by human error can be prevented, because the system estimates both stress and fatigue of operators in nuclear power plant.

Intermittent heat transport using hydrogen absorbing alloys

Abstract Hydrogen absorbing alloys enable heat to be transported over long distances using hydrogen as the transport medium, with theoretically very little heat loss. This report describes the system structure of a newly proposed heat transport system and an analysis of heat transport efficiency, and offers proof that a high efficiency of about 60% can be maintained by the system regardless of distance. Analytical results of a comparison between our transport method and a conventional method using heated water for the long-distance transport of intermittent heat (such as solar heat and plant waste heat) clearly show that transport by hydrogen enables the use of a more compact pipeline diameter for long-distance transport, that the rise time for heat transport is very short, that small-scale (2 kW) heat can be transported over a long distance, and that transport by hydrogen is much more efficient than transport by heated water for large-scale (100 kW) heat transport at distances over 2 km.

Relaxation of internal stress generated in hydrogen absorbing alloy vessels

Hydrogen absorbing alloys cause internal stress in reaction vessels due to the expansion that occurs when they absorb hydrogen. This stress is affected not only by the amount of reacting hydrogen but also by the ab/desorption cycles. In this paper, we analyze the reaction distribution in a reaction vessel through simulations and show that locally excess internal stress occurs near the heat media inlet. We also show that this excess stress is decreased by unifying the reaction ratio by exchanging heat between the heat media inlet and the outlet in the reaction vessel.