Heuristic approach to allocation of trucks in a transportation system

This paper considers the problem of how luggages should be assign to each truck for the transportation system consists of a depot, a fixed area and two types of luggages, called schedule problem. The main purpose of this paper is to propose a procedure for the problem subject to keep the balance of work loads among truck drivers. The procedure is based on 3 (heuristic) rules for replacing the addresses of each luggage with the ‘conventional address,’ converting size of each luggage into ‘weight’ and introducing a measure to keep the balance of work loads. The procedure consists of three stages according to ‘priority’ of the types of luggages. A case study is presented that demonstrate the practical usefulness of the procedure.     

Ultrahigh-sensitivity New Super-HARP camera

NHK led the world in developing a high-sensitivity Super-HARP pickup tube using the avalanche multiplication effect. The authors have now developed an improved version (2/3-inch, with electromagnetic focusing and electromagnetic deflection) which is eight times more sensitive and has much better lag characteristics. The handy New Super-HARP color camera which uses this newly-developed pickup tube has higher sensitivity than human vision (11 lux, F8), negligibly low lag, and a limiting resolution of over 700 TV lines. It will be a powerful tool in emergency news gathering at night, the production of scientific programs, and other applications     

Polycrystalline silicon thin-film transistors fabricated by defect reduction methods

Fabrication of n-channel polycrystalline silicon thin-film transistors (poly-Si TFTs) at a low temperature is reported. 13.56 MHz-oxygen plasma at a 100 W, 130 Pa at 250/spl deg/C for 5 min, and heat treatment at 260/spl deg/C with 1.3/spl times/10/sup 6/-Pa-H/sub 2/O vapor for 3 h were applied to reduction of the density of defect states in 25-nm-thick silicon films crystallized by irradiation of a 30 ns-pulsed XeCl excimer laser. Defect reduction was numerically analyzed. Those treatments resulted in a high carrier mobility of 830 cm/sup 2//Vs and a low threshold voltage of 1.5 V at a laser crystallization energy density of 285 mJ/cm/sup 2/.     

Carbon analysis for inspecting carbonation of concrete using a TEA CO2 laser-induced plasma

It has been demonstrated that a spectrochemical analysis of carbon using the laser plasma method can be successfully applied to inspect the carbonation of concrete by detecting carbon produced in aged concrete by a chemical reaction of Ca(OH)2 with CO2 gas in environmental air, turning into CaCO3, which induces degradation of the quality of building concrete. A comparative study has been made using a TEA CO2 laser (500-1000 mJ) and a Q-switched Nd-YAG laser (50-200 mJ) to search for the optimum conditions for carbon analysis, proving the advantage of the TEA CO2 laser for this purpose. Also, it was clarified that laser irradiation with suitable defocusing conditions is a crucial point for obtaining high sensitivity in the detection of carbon. Practical experiments on the inspection of carbonation were carried out using both a concrete sample that had been intentionally carbonated by exposure to high concentrations of CO2 gas and a naturally carbonated concrete sample. As a result, good coincidence was observed between the laser method and the ordinary method, which uses the chemical indicator phenolphthalein, implying that this laser technique is applicable as an in situ quantitative method of inspection for carbonation of concrete.     

New semiconducting silicides assembled from transition-metal-encapsulating Si clusters

We synthesized amorphous films composed of transition-metal-encapsulating Si clusters (MSi_n: M = Zr, Nb, Mo and W) by deposition of hydrogenated MSi_nH_x clusters onto solid substrates followed by annealing at 400-500 °C for dehydrogenation. The MSi_n (n = 7-20) cluster films are amorphous semiconductors with an optical gap > 0.4 eV and have larger electron and hole mobility than that of the hydrogenated amorphous Si (a-Si:H) film. In these films, while Si atoms form amorphous networks similar to those in a-Si:H films, the thermal stability is enhanced and the electronic disorder is reduced by the use of MSi_n clusters as the unit structures. Structure modeling by ab initio calculations for MSi_n films suggests that the encapsulated M atom works as a terminator of dangling bonds of the Si network.     

High quality SiO2/Si interfaces of poly-crystallinesilicon thin film transistors by annealing in wet atmosphere

A new post-metallization annealing technique was developed to improve the quality of metal-oxide-semiconductor (MOS) devices using SiO ₂ films formed by a parallel-plate remote plasma chemical vapor deposition as gate insulators. The quality of the interface between SiO₂ and crystalline Si was investigated by capacitance-voltage (C-V) measurements. An H₂O vapor annealing at 270°C for 30 min efficiently decreased the interface trap density to 2.0×10¹⁰ cm^-2 eV^-1, and the effective oxide charge density from 1×10 ¹² to 5×10⁹ cm^-2. This annealing process was also applied to the fabrication of Al-gate polycrystalline silicon thin film transistors (poly-Si TFT's) at 270°C. In p-channel poly-Si TFT's, the carrier mobility increased from 60-400 cm² V^-1 s^-1 and the threshold voltage decreased from -5.5 to -1.7 V     

Hepatotoxicity of halogenated inhalational anesthetics studied in rats hepatocytes

Effects of 2% halothane, 1.5% sevoflurane, 1.5% enflurane, and 1.2% isoflurane on hepatic dysfunction were studied using rat hepatocytes incubated in media containing 95% or 5% O2. The effects of anesthetics on hepatic perfusion were eliminated by incubation of hepatocytes for 45 minutes with each combination of anesthetic and oxygen concentration. After incubation, viability of hepatocytes was assayed by the LDH latency test. Enzyme (GPT, GOT, LDH) activities, lactate concentration and pyruvate concentration in the incubation medium were measured. The concentrations of adenine nucleotides and inorganic phosphorous in the liver were determined. Anesthetics administered in 95% O2 did not produce significant decreases in viability and enzyme release compared to 95% O2 alone. Halothane, sevoflurane, and isoflurane administered in 5% O2 produced significant decreases in viability and enzyme releases compared to 95% O2 alone. In groups administered 95% O2 there was a significant relationship between viability and energy charge in hepatocytes (P < 0.01). In the 5% O2 groups, there were significant relationships between viability and ATP in hepatocytes (P < 0.01) or L/P ratio in incubation medium (P < 0.01). These results suggest that the combination of anesthetics and hypoxia produce hepatotoxicity. Destruction of energy status might be the cause of hepatotoxicity.