Development of a quasi-monoenergetic neutron field using the 7Li(p,n)7Be reaction in the energy range from 250 to 390 MeV at RCNP

A quasi-monoenergetic neutron field using the (7)Li(p,n)(7)Be reaction has been developed at the ring cyclotron facility at the Research Center for Nuclear Physics (RCNP), Osaka University. Neutrons were generated from a 10-mm-thick Li target injected by 250, 350 and 392 MeV protons and neutrons produced at 0 degrees were extracted into the time-of-flight (TOF) room of 100-m length through the concrete collimator of 10 x 12 cm aperture and 150 cm thickness. The neutron energy spectra were measured by a 12.7-cm diam x 12.7-cm long NE213 organic liquid scintillator using the TOF method. The peak neutron fluence was 1.94 x 10(10), 1.07 x 10(10) and 1.50 x 10(10) n sr(-1) per muC of 250, 350 and 392 MeV protons, respectively. The neutron spectra generated from various thick (stopping length) targets of carbon, aluminium, iron and lead, bombarded by 250 and 350 MeV protons, were also measured with the TOF method. Although these measurements were performed to obtain thick target neutron yields, they are also used as a continuous energy neutron field. These neutron fields are very useful for characterising neutron detectors, measuring neutron cross sections, testing irradiation effects for various materials and performing neutron shielding experiments.     

Highly sensitive MALDI analyses of glycans by a new aminoquinoline-labeling method using 3-aminoquinoline/α-cyano-4-hydroxycinnamic acid liquid matrix

In glycomics, mass spectrometry is an indispensable tool for high throughput analyses. Generally speaking, glycans contain many hydroxyl groups and are more difficult to ionize than peptides. Derivatization of glycans has been useful for increasing sensitivity. However, it takes time to purify and causes loss of sample. Here, we show a highly sensitive aminoquinoline (AQ)-labeling method of glycans on a matrix-assisted laser desorption/ionization (MALDI) target using a liquid matrix 3-aminoquinoline (3-AQ)/α-cyano-4-hydroxycinnamic acid (CHCA). It is a rapid procedure and reduces loss of sample material during the reaction process, especially in negative ion mode where 10 amol of monosialylated N-glycan were detected as AQ-labeled molecular ions. In addition, MS/MS of 10 amol of monosialylated N-glycan was achieved.     

资源节约型高强度电工钢SXRC的开发

日本住友金属成功地开发了一种资源节约型高强度无取向电工钢SXRC,这种电工钢是通过固溶铌适度抑制位错的合并对消而得到一种特殊的微观组织,因此兼具很高的力学性能和磁性,特别适用于HEV、EV驱动电机转子.而且,不使用昂贵的镍就可以达到期望的强度,合金成本可控,是一种优越的资源节约型产品.     

Onion-like carbon-encapsulated Co,Ni, and Fe magnetic nanoparticles with low cytotoxicity synthesized by a pulsed plasma in a liquid

We synthesized onion-like carbon-encapsulated Co, Ni, and Fe (Co–C, Ni–C, and Fe–C) magnetic nanoparticles with low cytotoxicity using pulsed plasma in a liquid. The pulsed plasma is induced by a low-voltage spark discharge submerged in a dielectric liquid. The face-centered cubic Co and Ni, and body-centered cubic Fe core nanoparticles showed good crystalline structures with an average size between 20 and 30 nm were encapsulated in onion-like carbon coatings with a thickness of 2–10 nm. Vibrating-sample magnetometer measurements revealed the ferromagnetic properties of as-synthesized samples at room temperature (Co–C = 360 Oe, Fe–C = 380 Oe, and Ni–C = 211 Oe). Raman-spectroscopy analysis found onion-like carbon shells composed of well-organized graphitic structures. Thermal gravimetric analysis showed a high stability of the as-synthesized samples under thermal treatment and oxidation. Cytotoxicity measurements showed higher cancer cell viability than samples synthesized by different methods.     

Probabilistic models of combinations of stochastic loads for limit state design

When more than one load act on a structure, the maximum intensity of the combined load effect needs to be evaluated. Turkstra's rule is often used in reliability-based limit state design because of its simplicity; however, the approximation is unconservative. This paper presents the theoretical expressions of the cumulative distribution function (cdf) of the maximum intensity during a reference period taking the temporal variation of load intensity into account. Theoretical investigation and numerical examples show that the theoretical expression provides a fairly good estimate regardless of the statistical characteristics of the load processes. To avoid considering time-dependency in determining a design point, it is proposed to consider the intensities of the load processes at the time when the combination takes its maximum value. Based on the observation that the cross section of the joint probability density function (pdf) of these intensities cut by the limit state surface is similar to that of the joint pdf of the basic random variables, the design point is determined in the basic variable space using AFOSM.     

Hole trapping in polydiacetylene field effect transistor studied by optical second harmonic generation

Hole trapping in polydiacetylene field effect transistor (PDA-FET) was studied by the electric field induced second harmonic generation (EFISHG). Response of SHG signal from PDA-FET with an application of external voltage was monitored. Applying positive voltage to source and drain electrodes with respect to gate electrode, SHG signal was not observed during bias application, whereas the signal was enhanced after turning off the bias. Since positive bias promotes hole injection from source and drain electrodes, electric field formed by trapped holes in PDA layer activated the SHG signal. Microscopic SHG measurement implies that the trapped holes are concentrated around source and drain electrodes.     

Rhodium-incorporated faujasite prepared at 80 °C

Rhodium-incorporated zeolites were synthesized from orthosilicate, aluminum nitrate, and rhodium chloride at 80 °C. Crystal phase diagram (zeolite types as functions of rhodium feed ratio and reaction period) showed that pure faujasite was formed in a wide range, but prolonged reaction caused partial transformation from faujasite to cancrinite at the rhodium feed ratio Rh/(Al + Rh) ≤ 0.02 and to gismondine at Rh/(Al + Rh) ≥ 0.4. X-ray diffraction analysis illustrated that an increase in the rhodium feed ratio caused appreciable decreases in the d-spacings, suggesting that rhodium was incorporated into the faujasite framework. ICP-OES analysis for the products showed that the rhodium content increased almost linearly with the increase in the rhodium feed ratio with an upper limit of the analyzed Rh content Rh/(Al + Rh) = 0.183 at the Rh feed ratio of 0.3. The products were almost quantitatively ion-exchanged using an ammonium chloride aqueous solution to study the ammonia desorption profiles on TG-DTA/MS analysis in the heating process. Considerably sharp exothermic peaks were observed at 245 °C simultaneously in the heating process. These peaks are probably related to catalytic decomposition of ammonia and desorption of ammonia, nitrogen, and water in the zeolite. A hypothesis was proposed for this mechanism: rhodium can be abruptly eliminated at an elevated temperature from the zeolite framework toward the micropores to form its hydroxides or oxides, then they triggered a catalytic decomposition of the adsorbed ammonia. The effect of calcination on crystallinity of the products and catalytic reactivity for hydrogen peroxide decomposition supported the proposed mechanism.     

Characterization of Antioxidants Extracted from Thai Riceberry Bran Using Ultrasonic-Assisted and Conventional Solvent Extraction Methods

Riceberry bran (RBB), a waste product from rice processing, contains several antioxidants with potential health benefits. This study aims to compare the two main parameters affecting the extraction efficiency of antioxidants from RBB, namely, the extraction technique (ultrasonic-assisted extraction (UAE) and conventional solvent extraction) and solvent (ethanol and d-limonene). The highest values of total phenolic content, total flavonoid content, total anthocyanin content, and antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and ferric reducing antioxidant power (FRAP) assays were detected in ethanolic extracts obtained by UAE. High-performance liquid chromatography investigation of the chemical composition of RBB revealed five major groups of antioxidants: (1) phenolic acids, including protocatechuic acid, vanillic acid, p-coumaric acid, ferulic acid, and sinapic acid; (2) flavonoids, including rutin, myricetin, and quercetin 3-glucuronide; (3) anthocyanins, including cyanidin 3-glucoside and peonidin 3-glucoside; (4) vitamin E, including γ-tocotrienol, β-tocotrienol, δ-tocopherol, γ-tocopherol, and α-tocopherol; and (5) γ-oryzanol. Protocatechuic acid exhibited the highest DPPH radical scavenging activity and FRAP values, whereas the lowest values were observed for γ-oryzanol.     

Characteristics of a MHD power generator using a low-melting-point Gallium alloy

An experimental investigation of a magneto hydrodynamics power generator using a low-melting-point Gallium alloy at high Reynolds numbers is presented in this paper. The power output is found to increase with increasing the flow Reynolds number. By considering the non-uniform distribution of the magnetic field in the test channel, theoretical evaluation gives a more accurate prediction to the experimental data. The present generator demonstrates the maximum power generation efficiency of $8.3\times 10^{-4}$  % and the maximum output electric power of 1.5 mW.     

Analytical method of cereulide in processed cereal-based foods and milk powder by LC-MS/MS

An LC-MS/MS method for analysis of cereulide, an emetic toxin produced by Bacillus cereus, was developed. Cereulide was extracted from samples, fried rice, pan-fried noodles, red bean paste and baby formula, with methanol and purified using Oasis HLB cartridges. LC separation was performed on a C18 column with a mixture of formic acid solution and methanol containing ammonium formate as a mobile phase, and the mass spectrometer was operated in the positive electrospray ionization mode. Performance evaluation showed that trueness was higher than 70% and repeatability and reproducibility were within 10%. The limits of quantification were lower than 1 μg/kg.