Abstract
The J-PARC E16 experiment measures mass spectra of low-mass vector mesons,
ρ
,
ω
, and
ϕ
, in nuclei via
e
+
e
-
decays. Vector mesons are produced in
p
A reactions. A spectrometer with ...a large acceptance and a high-intensity beam up to 1
× 10
10
protons per ∼2-sec duration pulse are utilized to collect a sufficient number
of vector mesons. We have developed a spectrometer, which has two types of electron
identification detectors: a hadron blind detector (HBD) and a lead-glass calorimeter.
Commissioning runs have been performed at the J-PARC high-momentum beam line. The HBD
successfully observed on average 11 ± 1 photoelectrons for an incident electron. We achieved
the pion rejection of 0.9 ± 0.2% with the electron detection efficiency of 61 ± 4% for
the HBD, which was consistent of the expected performance.
Dense Al2O3-based composites (99.0% of theoretical or more) dispersed with carbon nanofibres (CNFs) were fabricated using pulsed electric-current pressure sintering for 5 min at 1300 C and 30 MPa in ...a vacuum. The dispersion of CNFs into the matrix depended much on the particle size of the starting Al2O3 powders. Mechanical properties of the composites were evaluated in relation to their microstructures; high values of three-point bending strength sigmab (about 800 MPa) and fracture toughness KIC (about 5 MPa.m1/2) were attained at the composition of CNF/Al2O3 = 5:95 vol%. Sigmab and KIC values were about 25% and about 5%, respectively, higher than those of monolithic Al2O3. This might be due to the small Al2O3 grains (1.6 micron) of dense sintered compacts compared with 4.4 micron for the pure Al2O3 ceramics, resulting from the suppression of grain growth during sintering induced by uniformly dispersed CNFs in the matrix. Electrical resistivity of CNF/Al2O3 composites decreased rapidly from > 10 exp(15) to about 2.1 x 10 exp(-2) ohm.m (5 vol% CNF addition), suggesting the machinability of Al2O3-based composites by electrical discharge machining. 29 refs.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
To assess the efficacy of different period of treatment for evaluating male reproductive toxicity in rats, reserpine was subcutaneously administered on a daily basis to male Sprague-Dawley rats at ...dosages of 0.05, 0.1 or 0.2 mg/kg for 2 weeks or at dosages of 0.05 or 0.1 mg/kg for 4 weeks. At the end of the administration period the animals were sacrificed and sperm counts, organ weights and histopathological changes in the reproductive organs were examined. The sperm number in the caudal epididymis and genital organ weights were not affected by reserpine with either 2- or 4-weeks treatment. In the 4-weeks study, histopathological examination of the testes revealed retention of step 19 spermatids in the seminiferous tubules of stages IX to XII and decreased secretory content of the prostate in the 0.05 and 0.1 mg/kg groups. In the 2-weeks study, although no distinct histopathological changes were observed in the 0.05 mg/kg group, decreased secretory content of the prostate, apoptosis of spermatocytes in the seminiferous tubules of stage VII and cell debris of the epididymis were observed in the 0.1 and 0.2 mg/kg groups. These results suggested that 2-weeks treatment with reserpine is sufficient for detection of testicular toxicity, although higher dosage levels are appropriate than for 4-weeks treatment.
In this report, we discussed the efficient usage of the developed practical devices by investigating the operation efficiency in the cleft grafting process of eggplant. Time required to graft one ...seedling was from 60 to 70% of the manual operation, and the grafting success ratio was equal or higher than that of the manual operation. It became clear that the practical devices ware applicable to the conventional grafting system. Group work, where each worker was allotted the portion of the grafting processes, had the advantage in the efficient usage of the devices compared with one-person operation. It also had the advantage in higher operation efficiency. By using the practical devices, the operation efficiency could remarkably be improve and grafting time was shortened in half.
Utilization of the rootstock cutting device and the scion cutting device was discussed to save the cleft grafting work. Practical cutting devices were developed on the basis of the prototypes ...reported previously. For the easy replacement of the cutting blades, the blades were assembled on a plastic base. The blades could be replaced with the plastic base more easily and safely compared with the prototypes. The developed practical devices have the cutting accuracy and operation efficiency equivalent to the prototypes. Time required to cut one rootstock was about 60% and time required to cut one scion was about 40% of the manual operation. As the result of the durability investigation, it was found clear that cutting edges can cut 2000 seedlings.
Abstract In this report, a prototype of scion cutting device was developed for saving the cleft grafting work in eggplant cultivation. It cut the hypocotyl into a wedge-shape. Fixing angle of cutting ...blades, diameter and hardness of the hypocotyl influenced the wedge angle of the hypocotyl. Also the wedge angle depended on the cutting position. The device could cut and shape the hypocotyl into a discretionary wedge angle by adjusting the cutting position. The cutting accuracy was equal or higher than that of the manual operation. Time required per one seedling was about 7 seconds, that was about 40% of the manual operation. It became clear that the developed device was practical.
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