The magnetism of grain boundary (GB) phases in the Nd-rich Ga-doped Nd-Fe-B sintered magnet that shows unusually high improvement in coercivity by post-sinter optimal heat treatment was studied using ...electron holography. Transmission electron microscopy observations identified three types of GB phases with distinct structures, i.e., Ia3¯-type, amorphous-type, and Nd6(Fe,Ga)14-type. The magnetic flux densities of these three GB phases were systematically analyzed by measuring the phase shifts of incident electrons, and all of these GB phases are concluded to be nonferromagnetic. Unlike the standard commercial sintered magnets, this study has shown that the Nd2Fe14B grains in the optimally heat treated Nd-rich Ga-doped sintered magnet are exchange decoupled by the formation of the three types of nonferromagnetic GB phases. The observations provide useful information for GB engineering of Nd-Fe-B sintered magnets, which is key for further improvements of their coercivities without relying on grain size refinement.
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•Magnetization of the grain boundary phases in Ga-doped Nd-Fe-B magnet was studied.•Three types of grain boundary phases were observed in this sintered magnet.•Electron holography revealed that the grain boundary phases were nonferromagnetic.•The result provides useful information for the grain boundary engineering of sintered magnets.
Summary
The number of elderly patients with esophageal cancer has increased in recent years. The use of thoracoscopic esophagectomy has also increased, and its minimal invasiveness is believed to ...contribute to postoperative outcomes. However, the short- and long-term outcomes in elderly patients remain unclear. This study aimed to elucidate the safety and feasibility of minimally invasive esophagectomy in elderly patients. This retrospective study included 207 patients who underwent radical thoracoscopic esophagectomy for thoracic esophageal squamous cell carcinoma at Kobe University Hospital between 2005 and 2014. Patients were divided into non-elderly (<75 years) and elderly (≥75 years) groups. A propensity score matching analysis was performed for sex and clinical T and N stage, with a total of 29 matched pairs. General preoperative data, surgical procedures, intraoperative data, postoperative complications, in-hospital death, cancer-specific survival, and overall survival were compared between groups. The elderly group was characterized by lower preoperative serum albumin levels and higher American Society of Anesthesiologists grade. Intraoperative data and postoperative complications did not differ between the groups. The in-hospital death rate was 4% in the elderly group, which did not significantly differ from the non-elderly group. Cancer-specific survival was similar between the two groups. Although overall survival tended to be poor in the elderly group, it was not significantly worse than that of the non-elderly group. In conclusion, the short- and long-term outcomes of minimally invasive esophagectomy in elderly versus non-elderly patients were acceptable. Minimally invasive esophagectomy is a safe and feasible modality for elderly patients with appropriate indications.
Hybrid integration of multiple optical chips in three dimensions is an important technology for realizing highly functional, compact optoelectronic microsystems. In this paper, we report successful ...3-D integration of optical chips performed using Au-Au surface-activated bonding (SAB) at a relatively low bonding temperature of 150degC. A glass substrate with the flip-chip-bonded photodiode chips was vertically stacked on a Si substrate with the bonded laser diode chip using Au-Au SAB. By applying this technique, compact and thin optical microsensors (2.8 mm times 2.8 mm times 1 mm thick) were fabricated. The feasibility of measuring velocity was demonstrated using prototype microsensors.
We present a field-programmable gate array (FPGA)-based technique for the on-line identification of highly ionizing particles in a liquid xenon (LXe) detector. The method was developed and ...successfully exploited to select <inline-formula> <tex-math notation="LaTeX">\alpha </tex-math></inline-formula> particles emitted by 241 Am sources submerged in LXe in an overwhelming, mostly beam-related, <inline-formula> <tex-math notation="LaTeX">\gamma </tex-math></inline-formula>-ray background. After revising the main features of xenon and other liquid noble gases as ultra-violet (UV) scintillating media, we describe the algorithm idea and its firmware implementation. We then present the results in terms of efficiency and background suppression for the real-time <inline-formula> <tex-math notation="LaTeX">\alpha </tex-math></inline-formula>-particle tagging and the limits of the MEG trigger configuration. Finally, we show that in MEG II we are going to overcome the main issues and further improve the performances.
A low-temperature bonding of vertical-cavity surface-emitting laser (VCSEL) chips on Si substrates was achieved by using plasma activation of Au films. After the surfaces of Au films were cleaned ...using an Ar radio frequency plasma, bonding was carried out by contact in ambient air with applied static pressure. The experimental results showed that surface morphological change (the reduction of asperity width) as well as removal of adsorbed organic contaminants by plasma treatment significantly improved the quality of joints. At a bonding temperature of 100degC, the die-shear strength exceeded the failure criteria of MIL-STD-883.
Abstract
Recently, the development of autonomous ships has been progressing worldwide; thus, it is essential to ensure the safety of these ships for their successful realization. In previous studies, ...task-based hazard identification (HAZID) methods were developed as safety assessment methods for autonomous ships to identify hazards related to the tasks of ship operators. In this paper, a dynamic-task-based HAZID (DTB-HAZID) method, which is an improvement on the previously developed task-based HAZID method, is proposed, and the results of the risk analysis obtained from applying this method to a small experimental ship, Shinpo, are reported. The DTB-HAZID method was designed to analyze time-related hazards such as task delays and the simultaneous occurrences of tasks. To achieve this, the activity diagram, which is a type of unified modeling language (UML) model, was introduced to create task flow diagrams. In the risk analysis, first, the tasks of the operator who remotely navigated Shinpo were analyzed, and the corresponding task flow diagrams were created. Then, the time-related hazards were identified with reference to these diagrams. Finally, the obtained hazards were reviewed, and the applicability of the proposed method in hazard analysis from the perspective of time was discussed.
Membrane spanning regions can be used as markers for studying the robustness of biologically important units of proteins against evolutionary change (R. Sawada and S. Mitaku, Genes to Cells, 2010). ...We carried out computational experiments of extensive DNA mutations on the assumption of constant GC content or constant codon positional nucleotide biases. Randomized sequences were evaluated by membrane protein prediction systems SOSUI and SOSUIsignal. When all amino acid sequences from the total real genomes of 538 prokaryotes were analysed, ratios of membrane proteins to all genes in the total genomes were almost constant around a ratio of 22% with a standard deviation of 1.56. When the nucleotide sequences were randomized, keeping only the GC contents constant, the ratios of membrane proteins became highly diverse with a standard deviation of 10.1. When the codon positional nucleotide biases were taken into account; however, the diverse ratios of membrane proteins converged to a value of ∼25% with a standard deviation of 3.55. These results suggest that codon compositional biases play an important role in the evolution of prokaryotes for maintaining a constant ratio of membrane proteins. Further detailed analysis suggested that non-uniform nucleotide compositional biases at the terminal regions are the reason for the small but significant deviation.
When designing a protective barrier in order to protect a railway from debris flow, the debris flow evaluates the effect which it has on a protective barrier, and examines a wall and basic structure. ...In this case, if debris flow can evaluate the influence which it has on a protective barrier as an external force like earth pressure, the design method of a retaining wall can be applied and a protective barrier can be designed. Then, ground displacement caused by liquefaction referred to the valuation method of external force exerted on a structure. In addition, the debris flow examines how to evaluate the influence which it has on a protective barrier as an external force. As a result, the debris flow was considered as viscous fluid and the external force which acts on a protective barrier has been presumed by asking for the viscous coefficient and drift velocity of the debris flow. Moreover, it was shown that applying the design method of a retaining wall and the design of a protective barrier is attained.
The cross sections of the ^{7}Be(n,α)^{4}He reaction for p-wave neutrons were experimentally determined at E_{c.m.}=0.20-0.81 MeV slightly above the big bang nucleosynthesis (BBN) energy window for ...the first time on the basis of the detailed balance principle by measuring the time-reverse reaction. The obtained cross sections are much larger than the cross sections for s-wave neutrons inferred from the recent measurement at the n_TOF facility in CERN, but significantly smaller than the theoretical estimation widely used in the BBN calculations. The present results suggest the ^{7}Be(n,α)^{4}He reaction rate is not large enough to solve the cosmological lithium problem, and this conclusion agrees with the recent result from the direct measurement of the s-wave cross sections using a low-energy neutron beam and the evaluated nuclear data library ENDF/B-VII.1.
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