Tensile strain dependence of critical current of RHQ-Nb3Al wires

Nb₃Al superconducting wires produced by rapid heating and quenching (RHQ) have been developed for high-field accelerator magnets. It is known that critical currents of A15 superconductors (e.g., Nb₃Al and Nb₃Sn) have a dependence on stress/strain. It is thus important to clarify the stress/strain behavior of the RHQ-Nb₃Al wires for the development of high-field accelerator magnets. We recently started experimentally investigating the strain dependence of the critical current of the RHQ-Nb₃Al wires with a Ta interfilament by measuring their critical currents under longitudinal tensile strains. To evaluate the effect of residual strain in Nb₃Al filaments induced by thermal contraction of the materials in the wire, neutron diffraction measurements were performed at room temperature.     

Coalesced C60 Molecules in Toluene Under Ultrahigh Pressure

Abstract

We present mass spectral evidence that coalesced C60 dimers and trimers were formed in toluene under 1.2-1.4 GPa at room temperature.     

Clustering triple microbeads in a dynamic microarray for timing-controllable bead-based reactions

In this study, we developed a dynamic microfluidic device that enables the clustering of three different types of microbeads in a trapping spot and the rearrangement of contacting modes of the clustered microbeads. To achieve these two functions, two features are added to the conventional dynamic microfluidic device. (1) To trap multiple beads, an extended trapping spot with sub-by-pass channels and a valve was employed. (2) To rearrange the clustered microbeads, trapping spots that work only by backward flow were added. The design of the microfluidic device was realized by calculations based on fluidic resistance. By using the designed device, we successfully clustered different types of hydrogel microbeads including target materials, and observed reactions between clustered microbeads. In addition, by rearranging the contacting modes of the clustered microbeads, the reaction could be initiated/terminated at the desired time. We found that this dynamic microfluidic device is applicable to the quantitative analysis of chemical reactions between small amounts of multiple materials.     

Quantitative determination of the role of lettuce leaf structures in protecting Escherichia coli O157:H7 from chlorine disinfection

Viability of Escherichia coli O157:H7 cells on lettuce leaves after 200 mg/liter (200 ppm) chlorine treatment and the role of lettuce leaf structures in protecting cells from chlorine inactivation were evaluated by confocal scanning microscopy (CSLM). Lettuce samples (2 by 2 cm) were inoculated by immersing in a suspension containing 10(9) CFU/ml of E. coli O157: H7 for 24+/-1 h at 4 degrees C. Rinsed samples were treated with 200 mg/liter (200 ppm) chlorine for 5 min at 22 degrees C. Viability of E. coli O157:H7 cells was evaluated by CSLM observation of samples stained with Sytox green (dead cell stain) and Alexa 594 conjugated antibody against E. coli O157:H7. Quantitative microscopic observations of viability were made at intact leaf surface, stomata, and damaged tissue. Most E. coli O157:H7 cells (68.3+/-16.2%) that had penetrated 30 to 40 microm from the damaged tissue surface remained viable after chlorine treatment. Cells on the surface survived least (25.2+/-15.8% survival), while cells that penetrated 0 to 10 microm from the damaged tissue surface or entered stomata showed intermediate survival (50.8 +/-13.5 and 45.6+/-9.7% survival, respectively). Viability was associated with the depth at which E. coli O157:H7 cells were in the stomata. Although cells on the leaf surface were mostly inactivated, some viable cells were observed in cracks of cuticle and on the trichome. These results demonstrate the importance of lettuce leaf structures in the protection of E. coli O157:H7 cells from chlorine inactivation.     

Isolation and characterization of Candida albicans homologue of RAP1, a repressor and activator protein gene in Saccharomyces cerevisiae

To study the function of RAP1, a Candida albicans gene (CaRAP1) that shows sequence similarity to RAP1 of Saccharomyces cerevisiae was isolated by colony hybridization. DNA sequencing predicted an open reading frame of 429 amino acids with an overall identity of 24% to the ScRap1p. The DNA binding domain (DBD) was highly conserved, and EMSA using a GST-CaRap1p fusion protein confirmed its binding ability to the RPG-box of S. cerevisiae ENO1. In contrast, the N-terminus was less conserved and a moderate homology was observed in the BRCT domain. Interestingly, CaRap1p did not contain the C-terminal activation/repression region of ScRap1p.     

Existence of a tungsten-binding protein in Acidithiobacillus ferrooxidans AP19-3

A tungsten-binding protein was purified from a plasma membrane preparation of the iron-oxidizing bacterium, Acidithiobacillus ferrooxidans AP19-3 in an electrophoretically homogenous state. The protein was composed of two subunits with apparent molecular masses of 12 and 20.7 kDa. The molecular mass of the native protein was estimated to be 26.4 kDa in the presence of 1.5% 1-o-octyl-D -glucopyranoside (OGL), indicating that the native tungsten-binding protein is a heterodimeric protein. The amounts of tungsten bound to 1 mg of plasma membranes of A. ferrooxidans AP19-3 and the purified tungsten-binding protein at pH 3.0 were 191 and 1506 mug, respectively. In contrast, the amounts of tungsten bound to 1 mg of albumin, aldolase, catalase, chymotrypsinogen A, ferritin, and ferredoxin at pH 3.0 were 13.1, 18.6, 12.8, 16.6, 11.4, and 6.1 mug, respectively. Incubation of the tungsten-binding protein for 1 h with 10 mM Na(2)WO(4) plus 10 mM metal ion, such as NaVO(3), Na(2)MoO(4), CuSO(4), NiSO(4), MnSO(4), CoSO(4), or CdCl(2), did not markedly affect the amount of tungsten bound to the tungsten-binding protein, suggesting that the protein specifically binds tungsten.     

High-Entropy Alloys with a Hexagonal Close-Packed Structure Designed by Equi-Atomic Alloy Strategy and Binary Phase Diagrams

High-entropy alloys (HEAs) with an atomic arrangement of a hexagonal close-packed (hcp) structure were found in YGdTbDyLu and GdTbDyTmLu alloys as a nearly single hcp phase. The equi-atomic alloy design for HEAs assisted by binary phase diagrams started with selecting constituent elements with the hcp structure at room temperature by permitting allotropic transformation at a high temperature. The binary phase diagrams comprising the elements thus selected were carefully examined for the characteristics of miscibility in both liquid and solid phases as well as in both solids due to allotropic transformation. The miscibility in interest was considerably narrow enough to prevent segregation from taking place during casting around the equi-atomic composition. The alloy design eventually gave candidates of quinary equi-atomic alloys comprising heavy lanthanides principally. The XRD analysis revealed that YGdTbDyLu and GdTbDyTmLu alloys thus designed are formed into the hcp structure in a nearly single phase. It was found that these YGdTbDyLu and GdTbDyTmLu HEAs with an hcp structure have delta parameter (δ) values of 1.4 and 1.6, respectively, and mixing enthalpy (ΔH _mix) = 0 kJ/mol for both alloys. These alloys were consistently plotted in zone S for disordered HEAs in a δ-ΔH _mix diagram reported by Zhang et al. (Adv Eng Mater 10:534, 2008). The value of valence electron concentration of the alloys was evaluated to be 3 as the first report for HEAs with an hcp structure. The finding of HEAs with the hcp structure is significant in that HEAs have been extended to covering all three simple metallic crystalline structures ultimately followed by the body- and face-centered cubic (bcc and fcc) phases and to all four simple solid solutions that contain the glassy phase from high-entropy bulk metallic glasses.     

A 1.0 V power supply, 9.3 GB/s write speed, Single-Cell Self-Boost program scheme for high performance ferroelectric NAND flash SSD

A Single-Cell Self-Boost (SCSB) program scheme is proposed to achieve a 1.0 V power supply operation in Ferroelectric (Fe-) NAND flash memories. The proposed SCSB scheme only self-boosts the channel voltage of the cell to which the program voltage V_PGM is applied in the program-inhibit NAND string. The program disturb is well suppressed at the 1.0 V power supply voltage in the proposed program scheme. The power consumption of the Fe-NAND at V_CC = 1.0 V decreases by 86% compared with the conventional floating gate (FG-) NAND at V_CC = 1.8 V without the degradation of the write speed. The number of NAND chips written simultaneously in Solid-State Drives (SSD) increases by 6.7 times and the 9.3 GB/s write throughput of the Fe-NAND SSD is achieved for an enterprise application.