308 research outputs found
Stability test results on the aluminum stabilized superconductor for the helical coils of LHD
Stability tests have been carried out on short samples of the aluminum/copper stabilized composite-type superconductors developed and used for the pool-cooled helical coils of the Large Helical Device. The waveform of the longitudinal voltage initiated by resistive heaters shows a short-time rise before reaching a final value, which seems to correspond to the diffusion process of transport current into the pure aluminum stabilizer. The propagation velocity has a finite value even for the transport current being lower than the recovery current, and it differs depending on the direction with respect to the transport current
Behavior of total peroxy and total organic nitrate concentrations at Suzu on the Noto Peninsula, Japan : Long-range transport and local photochemical production
application/pdfArticleAtmospheric Environment. 196, p.20-26journal articl
Copper recovery and reduction of environmental loading from mine tailings by high‐pressure leaching and sx‐ew process
The flotation tailings obtained from Bor Copper Mine contain pyrite (FeS2) and chalcopyrite (CuFeS2), these sulfide minerals are known to promote acid mine drainage (AMD) which poses a serious threat to the environment and human health. This study focuses on the treatment of mine tailings to convert the AMD supporting minerals to more stable forms, while simultaneously valorizing the mine tailings. A combination of hydrometallurgical processes of high-pressure oxidative leaching (HPOL), solvent extraction (SX), and electrowinning (EW) were utilized to recover copper from mine tailings which contain about 0.3% Cu content. The HPOL process yielded a high copper leaching rate of 94.4% when water was used as a leaching medium. The copper leaching kinetics were promoted by the generation of sulfuric acid due to pyrite oxidation. It was also confirmed that a low iron concentration (1.4 g/L) and a high copper concentration (44.8 g/L) obtained in the stripped solution resulted in an improved copper electrodeposition current efficiency during copper electrowinning.Moreover, pyrite, which is primarily in the mine tailings, was converted into hematite after HPOL. A stability evaluation of the solid residue confirmed almost no elution of metal ions, confirming the reduced environmental loading of mine tailings through re-processing
Test of High Temperature Superconducting REBCO Coil Assembly for a Multi-Frequency ECR Ion Source
Chong T.H., Fukuda M., Yorita T., et al. Test of High Temperature Superconducting REBCO Coil Assembly for a Multi-Frequency ECR Ion Source. IEEE Transactions on Applied Superconductivity 34, 1 (2024); https://doi.org/10.1109/TASC.2024.3360935.High temperature superconducting REBCO tape has the characteristic of maintaining high critical current density under strong external magnetic field, which makes it an ideal material for the construction of air-core electromagnets of accelerator and electron cyclotron resonance (ECR) ion source. In Research Center for Nuclear Physics, Osaka University, a non-insulated air-cored REBCO coil assembly has been constructed. This coil assebmly consists of three circular REBCO solenoid and six racetrack REBCO coil. This coil assembly will be used as an electromagnet of a multi-frequency ECR ion source, and is also developed as a key technology development of an air-core cyclotron. The magnetic field of this ion source are designed, and 77 K performance tests of the assembly are carried out in order to examine the capability of REBCO coils of inducing magnetic field under external field. In this work, the test results and the magnetic field designed for the ECR ion source will be presented and discussed
Apelin Deficiency Accelerates the Progression of Amyotrophic Lateral Sclerosis
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the selective loss of motor neurons. Recent studies have implicated that chronic hypoxia and insufficient vascular endothelial growth factor (VEGF)-dependent neuroprotection may lead to the degeneration of motor neurons in ALS. Expression of apelin, an endogenous ligand for the G protein-coupled receptor APJ, is regulated by hypoxia. In addition, recent reports suggest that apelin protects neurons against glutamate-induced excitotoxicity. Here, we examined whether apelin is an endogenous neuroprotective factor using SOD1G93A mouse model of ALS. In mouse CNS tissues, the highest expressions of both apelin and APJ mRNAs were detected in spinal cord. APJ immunoreactivity was observed in neuronal cell bodies located in gray matter of spinal cord. Although apelin mRNA expression in the spinal cord of wild-type mice was not changed from 4 to 18 weeks age, that of SOD1G93A mice was reduced along with the paralytic phenotype. In addition, double mutant apelin-deficient and SOD1G93A displayed the disease phenotypes earlier than SOD1G93A littermates. Immunohistochemical observation revealed that the number of motor neurons was decreased and microglia were activated in the spinal cord of the double mutant mice, indicating that apelin deficiency pathologically accelerated the progression of ALS. Furthermore, we showed that apelin enhanced the protective effect of VEGF on H2O2-induced neuronal death in primary neurons. These results suggest that apelin/APJ system in the spinal cord has a neuroprotective effect against the pathogenesis of ALS
Generation and Characterization of Conditional Heparin-Binding EGF-Like Growth Factor Knockout Mice
Recently, neurotrophic factors and cytokines have been shown to be associated in psychiatric disorders, such as schizophrenia, bipolar disorder, and depression. Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a member of the EGF family, serves as a neurotrophic molecular and plays a significant role in the brain. We generated mice in which HB-EGF activity is disrupted specifically in the ventral forebrain. These knockout mice showed (a) behavioral abnormalities similar to those described in psychiatric disorders, which were ameliorated by typical or atypical antipsychotics, (b) altered dopamine and serotonin levels in the brain, (c) decreases in spine density in neurons of the prefrontal cortex, (d) reductions in the protein levels of the NR1 subunit of the N-methyl-D-aspartate (NMDA) receptor and post-synaptic protein-95 (PSD-95), (e) decreases in the EGF receptor, and in the calcium/calmodulin-dependent protein kinase II (CaMK II) signal cascade. These results suggest the alterations affecting HB-EGF signaling could comprise a contributing factor in psychiatric disorder
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