The JUSTSAP experiment on STS-95

An instrumented flow cell in the form of a cylinder with differentially heated end walls and adiabatic sidewalls was flown on STS-95 as the Japan-US Thermal Science Accelerometer Project (JUSTSAP). The purpose of the experiment was to map disturbances in the thermal field during the course of a Shuttle mission in order to correlated them with various mission events and to determine if any global transport could be detected from second order, non-zero time average flows resulting from periodic accelerations (g-jitter). Significant disturbances in the thermal field were noted each time the Shuttle changed attitude, such as the maneuver to -Z solar inertial, which is done periodically for thermal conditioning. Burns from the main thrusters associated with the launch and retrieval of the Spartan satellite produced overturning flows, as might be expected. During extended periods in which the attitude was held constant, the perturbations to the thermal field correlate extremely well with calculated accelerations from gravity gradient and drag. Fair agreement was found between the observed temperature perturbations and those predicted from a modification of the analytical model developed by Bejan and Tien (B&T) for the flow and heat transfer in an infinite cylinder with a constant axial thermal gradient. A full three-dimensional computational fluid dynamic analysis with more realistic thermal boundary conditions provided better agreement after adjustments were made to account for the heat flow away from the measuring thermistors. Once calibrated with a reliable thermal model, the flow cell was found to serve as a high-precision accelerometer, capable of measuring the quasi-steady acceleration with a sensitivity of better than 0.1 micro-g in the presence of the higher amplitude g-jitter typical of Shuttle operations. Further, it was found that the gravity gradient acceleration accounted for virtually all of the observed quasi-steady accelerations during such extended periods. The thermal response time of the JUSTSAP was too slow to expect to see the effects of fluctuating first order flows resulting from the vibrational environment of the Shuttle. However, an indication of a change in the thermal field near the ends of the flow cell was seen during periods of crew exercise that may possibly be attributed to circulating eddies resulting from the higher order terms in the momentum equation. At higher amplitudes, these second order effects can produce non-zero time average flows of a global nature, as can the start-up transients in first-order periodic flows. No such effects were observed, thus it is possible to place an upper limit on the integrated power spectral density of the vibrational environment experienced as well as the nature of the start-up transients of the periodic flows.     

The ignition front of a fuel jet flame stabilized by a step

For a fuel jet flame stabilized by a two-dimensional, backward-facing step exposed to a subsonic air stream, an experimental study was made of the dependence of the ignition front of the flame on various physical quantities, such as the width of the fuel nozzle, the height of the step, the boundary-layer thickness of the air stream at the step, and the velocity of fuel ejection of the outer air stream. Propane was ejected parallel to the air stream from the nozzle placed at the top of the step. It is shown that when the boundary layer of the air stream is laminar, the distance from the nozzle to the ignition front, x_t, is given by the equation,

$\frac{x_l^2}{{\delta }^{*}{b}_n}=\alpha \frac{U_f}{U_a}$

where b_n is the width of the fuel nozzle, U_f the fuel ejection velocity at the nozzle, U_a the outer stream velocity of the air, δ^* the displacement thickness of the boundary layer of the air stream at the step, and α a dimensionless experimental constant. The location of the flame front does not depend on the height of the step. Further, the length of the recirculation zone formed downstream of the step and the burning limits of the flame were measured.     

Effects of addition of hindered phenol compounds to a segmented polyurethane with shape memory on mechanical yielding

The mechanical yielding behavior of the shape memory polyurethane (SMP) and its composite samples were investigated to verify the effect of addition of hindered phenol. The composite samples were prepared using SMP as matrix and hindered phenol (AO-80) as filler, and then tensile tests were carried out at a range of temperatures and with different fixed crosshead speeds. According to the tensile data at 25 °C, the yield stress was increased by adding AO-80. In terms of the Eyring theory, the activation volume of deformation units decreased with increase of the amount of AO-80 added. This is because the packing of the hard segments is enhanced by addition of AO-80. Consequently, it was suggested that the yield process is caused by the rotation of hard segment domains within the deformed plastic domains composed of glassy soft segments.     

Investigation of pesticide residues in foods distributed in Kitakyushu City

We investigated 160 kinds of pesticide residues in 715 samples of 116 kinds of foods distributed in Kitakyushu city. Sixty kinds of pesticides were detected in 55 kinds of foods (204 samples) in the range of 0.002-22 mg/kg. Five kinds of pesticides in 7 samples violated the residue standards and the indication of "unused". The detection ratios of unregulated pesticide in domestic and imported foods were 27.8 and 33.0%, respectively. Iprodione, dicofol, diethofencarb, procymidone and chlorfenapyr (for domestic food) and total bromine, benomyl, chlorpyrifos, dicofol, fenvalerate, cypermethrin and dimethoate (for imported food) showed relatively high detection ratios. Chinese cabbage, garland chrysanthemum, tomatoes and green teas (domestic) and broccoli, bananas, grapefruit, lemons, oranges, frozen edamame and frozen kidney beans (imported) showed high relative pesticide detection ratios. Residual pesticides were detected with relatively high frequency in imported fruits, imported frozen foods and imported processed foods.     

Effects of caffeine on event-related potentials: comparison of oddball with single-tone paradigms

A report is given of the 1st confirmed outbreak of Albizia versicolor poisoning in Malawi and the 1st natural outbreak reported in sheep and goats. Approximately 800 animals are estimated to have died over a 9-year period on a government farm near Lake Malawi. Deaths occurred exclusively from August to December when ripe dry pods that fell to the ground were ingested. The major clinical signs were hyperaesthesia, wild running, lateral recumbency with rapid leg movements, nystagmus and rapid blinking. Approximately 75% of clinical cases made a full and rapid recovery. Sheep more often showed signs of poisoning than goats which was attributed to inherent susceptibility rather than selective feeding. The majority of animals affected were under 1 year of age. A series of experiments was conducted and all animals dosed with 6.4 g/kg or more of dry pods died with typical clinical signs. Although A. versicolor is well known to the local population there appeared to be no appreciation of its toxicity. Poisonings are probably rare under traditional management systems.     

A new concept of nuclear fuel reprocessing by applying ion-exchange technology

The development of advanced technology for the spent nuclear fuel reprocessing should be achieved not only considering cost, non proliferation and reduction of radioactive wastes but also corresponding to both spent nuclear fuels of LWR and FBR.

We have proposed an ion exchange process for reprocessing using a new type ion exchanger developed to chemical method of U enrichment technology. This process possess possibility of a sharp cut in cost, since this ion exchanger is characterized by rapid adsorption-desorption rate dominating the treatment rate.

From the basic experimental results, this reprocessing process has been constructed by 3 ion exchanger columns which consist of a main separation column, the uranium-refining column and the plutonium-refining column.

Comparing ion exchange process with the conventional Purex process, this ion exchange process has many advantages such as the decrease in the number and size separation equipment, solvent-spent free and alkaline-liquid-spent free. With these advantages, this process is estimated that the construction cost of reprocessing process is greatly reduced comparing to the conventional process.     

CTL response to Mycobacterium tuberculosis: identification of an immunogenic epitope in the 19-kDa lipoprotein

The successful resolution of infection with Mycobacterium tuberculosis (M.tb) is believed to involve the induction of CTLs that are capable of killing cells harboring this pathogen, although little information is known about the MHC restriction or fine specificity of such CTLs. In this study, we used knowledge of the HLA-A*0201-binding motif and an immunofluorescence-based peptide-binding assay to screen for potential HLA-A*0201-binding epitopes contained in the 19-kDa lipoprotein of M.tb (M.tb19). CD8+ T cells derived from HLA-A*0201+ patients with active tuberculosis (TB) as well as tuberculin skin test-positive individuals who had no history of TB were used as effector cells to determine whether these epitopes are recognized by in vivo-primed CTLs. An in vitro vaccination system using HLA-A*0201+ dendritic cells (DCs) as APCs was used to determine whether these epitopes can sensitize naive CD8+ T cells in vitro, leading to the generation of Ag-specific CTLs. The results show that an HLA-A*0201-binding peptide comprised of residues 88 to 97 of M.tb19 (P88-97) is recognized by circulating CD8+ CTLs from both healthy tuberculin skin test-positive individuals and patients with active TB but not by tuberculin skin test-negative subjects. Moreover, dendritic cells pulsed with this peptide induced class I MHC-restricted CTLs from the T cells of healthy unsensitized persons. Finally, CTL lines that were specific for P88-97 were shown to lyse autologous monocytes that had been infected acutely with the H37Ra strain of M.tb. These results demonstrate that M.tb19 elicits HLA class I-restricted CTLs in vitro and in vivo that recognize endogenously processed Ag. Epitopes of the type identified here may prove useful in the design of an M.tb vaccine.     

The effect of washing and heat treatment on the surface characteristics of fluorocarbon resin-treated polyester

Polyester fabrics and films treated with two fluorocarbon resins were washed and heat treated. Water repellency, surface tension and ESCA measurements were carried out. Changes in the water repellency of the resin-treated polyester fabric caused by washing and heat treatment are related to modification of the chemical composition of the polyester surface.     

Mechanism of high Tc superconductivity and and anti-ferromagnetic order of high Tc oxides

We propose, here, new theory of high T_c superconductivity mechanism. The hole-Cooper pair formation and the Bose condensation of the Cooper pairs occur in the high T_c superconducting oxides such as Bi?Sr?Ca?Cu?O. The atractive interaction is due to the antiferromagnetic order and its fluctuation of CuO₂ plane. Dependence of T_c on the numbers of CuO₂ layers is quantitatively analized.