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The electrochemical performance of variously treated Ni-P-coated Si (Ni-P/Si) negative electrodes for lithium-ion batteries was investigated. X-ray diffraction analysis revealed the formation of nickel silicide (NiSi and NiSi2) after annealing, which improved the adhesion between the Ni-P coating layer and Si particles. Spotty Ni-P particles did not aggregate on an etched Si surface due to an anchor effect, even after annealing, whereas the particles aggregated on an untreated Si surface. An annealed Ni-P/(etched Si) negative electrode maintained a discharge capacity of 2000 mA h g-1 even at the 100th cycle in an organic electrolyte, which can be attributed to Ni-P particles remaining on the surface of the annealed Ni-P/(etched Si) electrode even after the charge-discharge test. The annealed Ni-P/(etched Si) electrode also exhibited superior cycle performance with a reversible capacity of 1000 mA h g-1 over 750 and 1100 cycles in an organic electrolyte containing film-forming additive and an ionic liquid electrolyte, respectively. Consequently, the annealed Ni-P/(etched Si) electrode achieved both high reversible capacity and long cycle life.

Most patients with myasthenia gravis (MG) have elevated levels of autoantibodies against the nicotinic acetylcholine receptor (AChR) at the neuromuscular junction, which leads to muscle weakness. We developed a fusion protein, AChR-Fc, as a novel therapeutic biomolecule for patients with MG and examined its efficacy. AChR-Fc was expressed by Chinese hamster ovary cells and purified. We examined the neutralizing activity and cellular cytotoxicity of AChR-Fc using anti-AChR antibody-producing hybridoma cells and serum samples from 16 patients with MG. The effects of AChR-Fc in vivo were also examined using rat MG models. AChR-Fc bound to anti-AChR antibodies and exhibited cytotoxicity against patient-derived antibody-producing B cells. Additionally, a dose-dependent improvement in the clinical signs of disease was observed in a rat MG model. AChR-Fc can diminish signs of MG by neutralizing anti-AChR antibodies and enhancing cytotoxicity against autoantibody-producing B cells. Thus, AChR-Fc can be a novel therapeutic biomolecule for patients with MG.

When electrons at relativistic velocities pass through a crystal plate, such as silicon, photons are emitted around the Bragg angle for X-ray diffraction. This phenomenon is called parametric X-ray radiation (PXR). The monochromaticity and directivity of PXR are adequate and the energy can be changed continuously by rotating the crystal. This study measured the mass attenuation coefficient around the K-shell absorption edge of Nb, Zr and Mo as a PXR application of monochromatic hard X-ray radiation sources.

Growth blocking peptide (GBP) is one of the growth regulators in lepidopteran insects. Using RT-PCR, we detected GBP expression in two insect cell lines from Mamestra brassicae, SES-MaBr-4 from the fat body and SES-MaBr-93 from hemocytes. The sizes of the RT-PCR products agreed with the sizes calculated from the GBP cDNA sequence. These findings suggest that GBP is a candidate for an essential growth factor in these insect cell lines.

Parametric X-ray radiation (PXR) at energies from 15 to 30 keV was produced by a 45 MeV electron linear accelerator (LINAC) using a silicon (Si) single crystal. The appropriate conditions for generation of good monochromatic hard X-ray fields by PXR were obtained with the LINAC by theoretical calculations and experiments. The PXR intensity increased approximately linearly with the electron energy in the electron energy range of several tens of MeV. The PXR energy increased linearly with the crystal rotation angle that depended on the reflection plane and the observation angle and did not depend on the electron energy. The obtained counts of PXR increased at large observation angles although the energy decreased. The experiments used Si plates with thicknesses of 200, 300, 400, 500, 530, and 625 μm. Differences in angular distribution by the thickness of the Si plates were established. The possibility for PXR applications to material research and other fields is discussed. The off angle of the polished (cut) plane of the crystal was accurately determined using the PXR and the attenuation coefficient around the K-shell absorption edge of Zr, Nb and Mo were measured.

The response of a wireline-type beam monitor was measured for electron beams with energies of 28 MeV and pulsewidths of 20 ps from an electron linear accelerator. The output waveform from the wireline pickup was calculated according to the general formulation for responses of beam monitors based on electromagnetic interaction. In the calculations, a transfer function H(/spl omega/) and an effective length l/sub eff/ are introduced to express all the effects not included in the analysis. The function H(/spl omega/) is assumed to be Gaussian, and the FWHM of H(/spl omega/) and l/sub eff/ is experimentally determined. The effects of the termination, wireline length, height, and angle between the wireline and the beam direction are discussed. The test supported the analysis and, for the standard pickup, a charge sensitivity of 20 V/nC and an FWHM of H(/spl omega/) of 55 ps are obtained.

A new neutron inverse kinetics method has been proposed to compute both reactivity and source strength using only noise-containing reactor power signals in a subcritical state. The method is applicable to cases when the effective source strength varies with a change in reactivity. A newly defined kinetics parameter, “Memorial Index”, is introduced to detect properly the start and end of a transient and to exclude time intervals that are ill-posed for numerical source strength estimation analysis based on the grouping method. Results for a numerical simulation analysis demonstrate that the revised analytic procedure incorporated with the Memorial Index enables one to continuously calculate precise values of both source strength and reactivity during a complicated subcriticality transient.

A study on the thermal annealing behavior of fission fragments in synthetic quartz crystals was performed for application of synthetic quartz to track detectors under high temperature circumstances: x -, y -, and z -cut quartz plates were exposed to fission fragments from 252 Cf and were annealed up to 750°C. It was found that track retention depended on the crystallographic structure: the annealing temperature, where the number of etched tracks was sharply reduced, was 550°C for the x - and y -cut plates and 750°C for z -cut plates. Track sizes decrease and disperse with reductions in the track retention.

A technique is presented for solving neutron diffusion equations with the boundary element method (BEM) based on a hierarchical domain decomposition technique. In this method, the reactor domain is decomposed into homogeneous regions and the boundary condition on the common boundary of regions is initially assumed. The neutron diffusion equation is solved iteratively at two levels of hierarchical structure: First, BEM is applied to solve the neutron diffusion equation of each homogeneous region under the given assumed boundary conditions and an assumed multiplication factor. Then, these assumed values are modified to satisfy the continuity conditions for the neutron flux and neutron current.The proposed technique is useful for multiregion problems with a large number of regions of complex geometry, where the finite difference approximation cannot be applied properly.

This paper presents a technique for solving the neutron diffusion equation with the boundary element method based on the domain decomposition method. In this technique, the domain region is decomposed into homogeneous regions. The boundary conditions on the common boundary of decomposed regions and the multiplication factor are initially assumed. The boundary conditions on the other boundary are given. The neutron diffusion equation is solved iteratively at two levels of a hierarchical structure: first, the boundary element method is applied to solve the neutron diffusion equation of each homogeneous region under given assumed boundary conditions and multiplication factor. These assumed values are then modified to satisfy the continuity conditions for the neutron flux and neutron current. The proposed technique is useful for multi-region problems with a large number of regions.

This paper describes a new approach to the radiological worker allocation problem using a multiple objective genetic algorithm. The worker allocation problem in radiological facilities involves various types of constraints and even mutually conflicting ones, such as individual dose limits, working time limits, etc. A major difficulty of this highly working time limits, etc. A major difficulty of this highly constrained problem is the way of finding an optimal solution in the huge search space where a large proportion of solutions are not feasible because some of the constraints cannot be satisfied. The paper proposes a model of evolution to establish an optimal assignment efficiently, based on the biological insights into the evolutionary process and heuristic ideas. The experimental results show a very rapid evolution to produce feasible solutions, and the application of multiple evaluation functions converges the feasible solutions to good ones. The genetic algorithm approach was found to be superior to the goal programming and simplex methods.

Several nuclear reactor diagnostic systems using neural networks have been proposed in recent years. Neural networks trained by backpropagation, the standard training algorithm, have certain problems such as local minima and long training times. In this paper, neural networks trained by genetic algorithms are used in a nuclear reactor diagnostic system to solve these problems. The system is tested by simulated data modeled on the experimental fast reactor JOYO, and two categories of abnormality (abnormal control rod vibration and abnormal coolant flow) are identified. The comparisons to networks trained by back-propagation also are discussed.

Inflammatory bowel disease (IBD) represents a group of chronic inflammatory diseases characterized by inflammation and relapsing gastrointestinal disorders. Recent studies have shown that Th17 cells, which are well known as key mediators of chronic inflammation, have a pivotal role in onset and development of IBD in humans and mice, alike. In recent years, it has been reported that IL-27, which is an IL-12-related heterodimeric cytokine consisting of EBI3 and p28 subunits, act directly on naive T cells to suppress the differentiation of Th17 cells. However, effects of exogenous IL-27 on the IBD are not well elucidated. To clarify the suppressive effect of IL-27 treatment on IBD, we applied the flexible linking method to EBI3 and p28 subunits and generated a single-chain human IL-27 (scIL-27). scIL-27 inhibited xenogenic mouse Th17 cell differentiation in vitro, indicating that scIL-27 also acts in mouse immune systems. In a 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced mouse acute colitis model, subcutaneous scIL-27 treatment significantly improved the colon length, extent of necrosis, and ulceration and thickened epithelium and several pathological scores in a dose-dependent manner. scIL-27 clearly suppressed several inflammatory cytokines, including IL-17, in inflamed colon, except for anti-inflammatory cytokine IL-10. The mesenteric lymph node cells from scIL-27-treated mice also exhibited a reduced inflammatory response and, furthermore, a lower population of Th17 cells than those of PBS-treated mice. Finally, we showed the therapeutic efficacy of scIL-27 on TNBS-induced colitis even after active colitis was established. These results suggest new possible therapeutic approaches for IBD, including disorders such as Crohn's disease and ulcerative colitis.

A simplified method in which the equivalent doses in tissue or organs and effective dose for external photon exposure according to the ICRP 1990 Recommendations could be approximated by a single empirical expression is proposed. In this method, the position of an organ is assumed to be the main factor that determine its dose for external photon irradiation. Many organ depths with different body size for ages 1, 5, 10 years and adults were determined using the cross-sections of mathematical organ descriptions, and effective depth for approximating effective dose was obtained with the organ depths assigned to tissue weighting factors.Compared with the precised data for adults by the Monte Carlo method, the simple expression gives good approximates for most of deep organs and effective dose within about 20% except some organs, especially for lateral geometry. It was found that irradiation geometry affects the variations in age-dependent effective dose, and that the effective depths for ages 1, 5, 10 years, normalized to the adults depth, are directly proportional to the cubic root of the body weight. The usefulness of the concept of effective depth was also discussed with regard to the specified point of effective does in the body, obtained from the combination of the depths for the three typical geometries.

This paper is concerned with an optimal planning in a multiple objective decision-making problem of allocating radiation workers to workplaces associated with occupational exposure. The model problem is formulated with the application of goal programming which effectively follow up diverse and conflicting factors influencing the optimal decision.The formulation is based on the data simulating the typical situations encountered at the operating facilities such as nuclear power plants where exposure control is critical to the management. Multiple goals set by the decision-maker/manager who has the operational responsibilities for radiological protection are illustrated in terms of work requirements, exposure constraints of the places, desired allocation of specific personnel and so on. Test results of the model are considered to indicate that the model structure and its solution process can provide the manager with a good set of analysis of his problems in implementing the optimization review of radiation protection during normal operation.

The authors describe calibration measurements for the efficiency and response function of the NE213 scintillator as an application of a two-dimensional pulse height analysis system. In this method, a /sup 252/Cf spontaneous fission source with a continuous spectrum is employed by taking each fission event as a pulsed neutron source, and the efficiency and response function of the NE213 scintillator can be estimated by two-dimensional measurements of the time-of-flight spectrum (neutron energy spectrum) and pulse height spectrum. >

(1996). A Higher Harmonics Analysis 3-D Neutron Diffusion Equation Using the Hierarchical Domain Decomposition Boundary Element Method. Journal of Nuclear Science and Technology: Vol. 33, No. 9, pp. 741-743.

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The effects of the presence of a central cavity on the space- and time-dependent neutron energy spectrum in a fast-neutron multiplying system are analyzed as a fundamental time eigenvalue problem b...

The frequency functions of photon particle intensity were experimentally determined for brems-strahlung produced by a 4MeV electron linac during a pulse width of 1.6 μsec. The measurements were carried out with a plastic scintillator and electronic integrator method, making it possible to separate multiple photons that are detected during a single linac pulse. The measured distributions were compared with the Poisson distribution with the same mean value, using the chi-square test. This method can be extended to the photon energy spectrum determination.

Maximum efficiency conditions of MHD power generation were derived as follows: (1) Spatially homogeneous distribution both of induced electromotive force and of the ratio of the applied magnetic induction to the density of a working fluid are required for irrespective of compressible or incompressibie plasmas. (2) In the case of incompressible plasmas, a homogeneous distribution of the magnetic induction is requested. (3) The magnitude of the required external loading at optimum and maximum efficiency power conversion is determined and it is proved that the optimum value of loading exists in a light load region.

The dynamic response of a feedback-type detection device for pulsed radiation measurements has been theoretically and experimentally investigated, and estimation made of the error incurred. The device is analyzed approximately as a linear second order lag system.A feed-back system is embodied, which consists of a side-window GM counter covered with movable shielding lead plate whose displacement from the origin indicates the output of the device.Experimental results and theoretical expressions both indicate that the mean value and the relative error of the output are proportional respectively to the intensity of radiation and to the square root there-of.

A formula of dead-time losses for pulse-modulated nuclear radiation was derived and experimentally verified. It was also clarified by the use of an electron linear accelerator that the intensity of nuclear radiation could be measured by counting rate measurements, if this dead-time correction was made.

A cellulose nitrate track detector, LR-115 (Type II), was studied experimentally to observe its neutron energy response when a radiator, such as fissionable material, is absent. The detector was exposed to monochromatic neutrons from the D (d, n) He reaction produced by a Van de Graaf accelerator. Through-etched and almost through-etched tracks in the detector were counted by two different methods: 1) optical microscope counting with an automatic image analyzing system and 2) spark counting. The detection sensitivity was obtained in the neutron energy region lower than 5 MeV and it was found that only α-particles from (n, α) reactions could be detected in both counting methods. We derived the counting probability of α-tracks induced in the detector and the threshold energies for neutron detection.

The energy-dependent absolute neutron sensitivity of a polycarbonate recoil track detector was measured for 4-6.5 MeV. The detector was irradiated with neutrons from a D(d,n)He reaction with the ETL Van de Graaff accelerator. After irradiation and chemical etching, the number of etched tracks was counted with an automatic track-counting system. The theoretical energy-dependent sensitivity was calculated using the local energy-loss theory of Katz and Kobeitch and agreed well with the observed results.

A new method for pulsed radiation measurements is studied by an application of the information theory of discrete systems. It is derived from entropy concept that in order to measure the photon density with the maximum conversion rate of a counter subjected to pulsed photon beams, the density λ of a Poisson source must satisfy the relation of λb=ln 2 when the resolving time τ of the counter lies between the pulse width b and the period (1/f). Actual devices using feedback circuits for satisfying the above condition are proposed.