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Nuclear reactors generate a highly intense flux of electron-antineutrinos from fission products through β−decay, and a slight amount of electron-neutrinos through either β+decay or electron capture. Neutrino energy spectra are usually calculated by the β decay theory. Since the reactor neutrinos are emitted from a great number of nuclides, the calculation requires a lot of level scheme of these nuclides. Nuclear data files, however, are available these days. It is possible to evaluate the electron-antineutrino and -neutrino spectra for a nuclear reactor on the basis of nuclear data files (JENDL-FP-Decay-Data-File-2000, JENDL-3.3)1, 2).In the study, we consider β transition of 420 nuclides for electron-antineutrino spectra and 120 nuclides for electron-neutrinos. We derive electron-neutrino and -antineutrino spectra in the energy range of 10 keV to 8 MeV from nuclear data files. The method gives good agreement with other studies for electron-antineutrino spectra. We show a simple method to estimate the reactor neutrino spectra without complicated computation.

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The polarization of neutron spin, target nucleus spin and He nuclear spin was developed at KEK for measuring the T-odd term in polarized neutron transmission through a polarized nuclear target. A method to measure the neutron spin rotation was developed for the T-violation experiment. This apparatus has been found to be quite useful for the P-violating neutron spin rotation experiment. The angular distribution of neutron-capture γ-rays was measured for the study of the enhancement mechanism of the P-violation. The results are also discussed.

Helicity dependence was observed for the resonance of the neutron radiative capture reaction of139La using a polarized neutron beam. The polarized neutron beam was produced by a dynamically polarized proton filter. The neutron polarization was about 70 % throughout the measurement. The preliminary result of the asymmetry in theγ-ray count was (9.5±1.2) %. Experiments were also carried out for98Mo,108Pd and129Xe. Such a large asymmetry as that found in139La was not observed in these nuclei.

Among mitochondrial encephalomyopathies, MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes, Pavlakis et al. 1983) is recognized as a distinct syndrome characterized by generalized convulsions and recurrent stroke-like episodes. The neuroradiological findings of three patients with MELAS are reported here. Retrospective review shows that MELAS should be included in the differential diagnosis of infarct-like lesions of the cerebrum.

The analyzing power for elastic pd scattering at 3.5 GeV has been measured in the region 0.1⩽−t⩽1.5 (GeV/c)2, using the polarized proton beam at KEK. The angular distribution shows a behavior similar to that in the lower energy region. It is reproduced fairly well by the predictions of a multiple scattering model based on the Glauber theory.

The Institute of Space and Astronautical Science (ISAS) is undertaking the launching of spacecraft for space observations and interplanetary explorations. The spherical rocket motor case of satellite launchers was made of Ti-6A1-4V alloy, however, to reduce the weight and fabrication cost, the material of the case was changed to Ti-15V-3Cr-3Sn-3AI alloy because of its good cold formability and the high strength. However, it was found that the hardness of weld joint was higher than that of base metal and the fracture toughness was lower when heat treated by a conventional aging process.This report describes the development of a new heat treatment process to obtain the high strength of base metal and the high fracture toughness of the weld joint, and the evaluation of the integrity of the weld joint by acoustic emission and radiography.The developed heat treatment process is as follows: after solution treatment, the motor case was aged at a relatively low temperature (preaging), welded, and then aged again (secondary aging). By applying this treatment, the strength of base metal was satisfactory, the fracture toughness of the weld metal was improved to be nearly the same as that of the base metal.The total AE event count during the fracture toughness test for the weld metal was almost the same as that for the base metal, when aged by the new method. On the other hand, the AE count was higher, when aged by a conventional process. This result was in accordance with the increase of the fracture toughness by the new heat treatment method.Radiograph testing showed that the size of weld defect was about half of the allowable sire, which was estimated by the fracture toughness and the maximum design stress at the weld metal of the motor case.

A new vitamin D3 metabolite was isolated in pure form (18.2 micrograms) from the serum of rats given large doses (two doses of 26 mumol/rat) of vitamin D3. The new metabolite has been unequivocally identified as 3 beta, 25-dihydroxy-9,10-seco-5,7,10(19)-cholestatrieno-26,23-peroxylactone by ultraviolet absorption spectrophotometry, Fourier transform infrared spectrophotometry, mass spectrometry, field desorption mass spectrometry, and specific chemical reaction with triphenyl phosphine. The stereochemical configuration at the C-23 and c-25 positions of the 25-hydroxyvitamin D3-26-23-peroxylactone was definitely determined to be the 23(S)25(R),25-hydroxyvitamin D3-26,23-peroxylactone is suggested for this metabolite. The isolation involved chloroform-methanol extraction and four column chromatographic procedures. The metabolite purification and elution position on these columns were followed by UV measurement at 264 nm. This metabolite was ultimately resolved from the previously known 25-hydroxyvitamin D3-26,23-lactone by high pressure liquid chromatography using a Zorbax Sil column. The 25-hydroxyvitamin D3-26,23-peroxylactone was converted upon storage at room temperature or -20 degrees C into the 25-hydroxyvitamin D3-26,23-lactone. Since under the conditions of this isolation only the 26,23-peroxylactone and no 26,23-lactone of 25-hydroxyvitamin D3 was present in the rat serum, this suggests that the 25-hydroxyvitamin D3-26,23-peroxylactone is the naturally occurring metabolite.

The asymmetryALLfor pp elastic scattering has been measured at 650 and 800 MeV in the region of Coulomb-nuclear interference. The real part of the double-spin-flip amplitude extracted from these data completes our determination of the forward pp scattering amplitudes at these energies. Comparison with the predictions of forward dispersion relations reveals a discrepancy in the spin-dependent channels at 650 MeV.

The heat that would be produced in a superthermal ultra-cold neutron source proposed by Golub and Pendlebury is evaluated when it is placed in a cold neutron field. The source strength achievable in the present technology is also discussed.

Aims/backgroundTo evaluate the extent of oxygen radical damage in the cornea after excimer laser ablation. MethodsThe 193 nm argon fluoride excimer laser was programmed for an average fluence of 150 mJ/cm², with a firing rate of 5 Hz and an ablation zone diameter of 6 mm. Phototherapeutic keratectomy was performed to remove 30 μm of epithelium and 50 μm of stroma from the corneas of New Zealand white rabbits. Oxidative tissue damage after laser was determined by measuring oxidised lipids (conjugated dienes and ketodienes) in corneal lipid extracts, and by fast blue B staining to localise the lipid peroxide in the tissue. ResultsConjugated diene levels were 3.73 (SD 0.56) nmol per hemicornea in ablated corneas and 1.99 (0.33) nmol per hemicornea in normal corneas (p = 0.0044). Ketodiene levels were 2.72 (0.38) nmol per hemicornea in treated corneas and 0.91 (0.12) nmol per hemicornea in normal corneas (p < 0.001). Fast blue B staining disclosed that the tissue damage occurred primarily on the surface of the ablated cornea. ConclusionThe presence of lipid peroxidation in the superficial corneal stroma in excimer laser treated corneas was demonstrated. This lipid peroxidation could be from oxygen free radicals generated by the infiltrating polymorphonuclear cells at the site of tissue damage.

This paper describes the liquid hydrogen system constructed for The Muon Ionization Cooling Experiment (MICE); MICE was built at the STFC Rutherford Appleton Laboratory to demonstrate the principle of muon beam phase-space reduction via ionization cooling. Muon beam cooling will be required at a future proton-derived neutrino factory or muon collider. Ionization cooling is achieved by passing the beam through an energy-absorbing material, such as liquid hydrogen, and then re-accelerating the beam using RF cavities. This paper describes the system creating the 22l of liquid hydrogen within the MICE beamline; the necessary safety engineering, the liquid hydrogen absorber and its associated cryogenic and gas systems are presented, along with its performance.

In a patient with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes [MELAS] who had normal mitochondrial enzyme activity, high doses of coenzyme Q10 (CoQ) were administered. Clinical improvement with decreased serum lactate and pyruvate levels was observed. Though the mechanism of action of CoQ is not known, a trial is worthwhile in patients with MELAS.