Spray Heat Transfer Analysis of Steel Making Process by Using ParticleBased Numerical Simulation

Spray cooling is often used in the steel manufacturing process, and the steel plate temperature at the time of manufacture affects productivity and quality. Therefore, the spray heat transfer coefficient estimation becomes important when determining manufacturing conditions or when designing manufacturing facilities. The conventional heat transfer coefficient estimation method is obtained by reversely analyzing the temperature of the steel plate when the heated steel plate is cooled by a single nozzle used or an experimental device simulating a real machine manufacturing facility. However, in actual equipment manufacturing facilities, it is difficult to grasp the heat transfer and flow state of heat transfer part details due to the presence of rolls, water staying on steel plates, and spray when a large amount of water is injected, heat transfer by numerical calculation Coefficient prediction has been desired. In order to calculate the actual physical phenomena even with a single spray, one hundred million droplets of about hundred micrometer diameter are calculated while resolving a few micrometers of vapor film thickness at the time of collision of the steel plates with droplets, so calculation load is huge.Therefore, the authors describe the heat transfer coefficient of the experimental results as a function of the collision pressure because the vapor film is broken and the heat transfer is promoted if the collision pressure of the spray droplets to the steel plate is high [1]. The heat transfer coefficient was calculated by substituting the collision pressure obtained by the numerical calculation into the experimental formula. The behavior of the spray cooling water includes a complex free interface, but can be calculated by the MPS method, and there is an example [2] where the flow rate of the spray cooling water between rolls of a real steel facility is calculated. In the present examination, the MPS method was similarly used for the prediction of the spray collision pressure, and the calculated particle diameter was also set to 3 mm as in the case [2]. As a result of examination, the particles were injected from the spray outlet so as to match the actual water density, and the actual droplet size was matched with the actual collision pressure

Micro-PIXE (Particle Induced X-Ray Emission) Analysis of Aluminum in Rat-Liver Using MeV Heavy Ion Microprobes

Heavy ion microprobes (HIM) such as 3 MeV Si2+ and 3 MeV p2+ have been applied to the elemental analysis by PIXE (proton-induced X-ray emission). It was found that silicon and phosphorus microprobes have several times higher sensitivity for aluminum Kα X-rays than 2 MeV proton microprobes, and detection limits were more favorable in a phosphorus microprobe. Using a 3 MeV p2+ microprobe, the liver of a rat, which had been injected with aluminum-lactate, was investigated and it was found that aluminum segregates in areas with a dimension of about 10 μm. These areas could hardly be observed with 2 MeV proton microprobes

Enhancing the Hot-Phonon Bottleneck Effect in a Metal Halide Perovskite by Terahertz Phonon Excitation

ハライドペロブスカイト半導体においてテラヘルツ励起によるホットキャリアの長寿命化を実現 --太陽電池材料のフォノン操作による高効率化への新たな指針--. 京都大学プレスリリース. 2021-02-19.We investigate the impact of phonon excitations on the photoexcited carrier dynamics in a lead-halide perovskite CH3NH3PbI3, which hosts unique low-energy phonons that can be directly excited by terahertz pulses. Our time-resolved photoluminescence measurements reveal that strong terahertz excitation prolongs the cooling time of hot carriers, providing direct evidence for the hot-phonon bottleneck effect. In contrast to the previous studies where phonons are treated as a passive heat bath, our results demonstrate that phonon excitation can significantly perturb the carrier relaxation dynamics in halide perovskites through the coupling between transverse- and longitudinal-optical phonons

Molecular mechanism of the recognition of bacterially cleaved immunoglobulin by the immune regulatory receptor LILRA2

金沢大学医薬保健研究域薬学系Human leukocyte immunoglobulin-like receptors (LILRs) typically regulate immune activation by binding to the human leukocyte antigen class I molecules. LILRA2, a member of the LILR family, was recently reported to bind to other unique ligands, the bacterially degraded Igs (N-truncated Igs), for the activation of immune cells. Therefore, LILRA2 is currently attracting significant attention as a novel innate immune receptor. However, the detailed recognition mechanisms required for this interaction remain unclear. In this study, using several biophysical techniques, we uncovered the molecular mechanism of N-truncated Ig recognition by LILRA2. Surface plasmon resonance analysis disclosed that LILRA2 specifically binds to N-truncated Ig with weak affinity (Kd = 4.8 mM) and fast kinetics. However, immobilized LILRA2 exhibited a significantly enhanced interaction with N-truncated Ig due to avidity effects. This suggests that cell surface-bound LILRA2 rapidly monitors and identifies bi- or multivalent abnormal N-truncated Igs through specific cross-linking to induce immune activation. Van\u27t Hoff analysis revealed that this interaction is enthalpy-driven, with a small entropy loss, and results from differential scanning calorimetry indicated the instability of the putative LILRA2-binding site, the Fab region of the N-truncated Ig. Atomic force microscopy revealed that N truncation does not cause significant structural changes in Ig. Furthermore, mutagenesis analysis identified the hydrophobic region of LILRA2 domain 2 as the N-truncated Ig-binding site, representing a novel ligand-binding site for the LILR family. These results provide detailed insights into the molecular regulation of LILR-mediated immune responses targeting ligands that have been modified by bacteria. © 2020 Yamazaki et al. Published under exclusive license by The American Society for Biochemistry and Molecular Biology, Inc

A Neural Correlate of the Processing of Multi-Second Time Intervals in Primate Prefrontal Cortex

Several areas of the brain are known to participate in temporal processing. Neurons in the prefrontal cortex (PFC) are thought to contribute to perception of time intervals. However, it remains unclear whether the PFC itself can generate time intervals independently of external stimuli. Here we describe a group of PFC neurons in area 9 that became active when monkeys recognized a particular elapsed time within the range of 1–7 seconds. Another group of area 9 neurons became active only when subjects reproduced a specific interval without external cues. Both types of neurons were individually tuned to recognize or reproduce particular intervals. Moreover, the injection of muscimol, a GABA agonist, into this area bilaterally resulted in an increase in the error rate during time interval reproduction. These results suggest that area 9 may process multi-second intervals not only in perceptual recognition, but also in internal generation of time intervals

Review Article : Feudalism or Absolute Monarchism?

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68809/2/10.1177_009770049001600304.pd

Spray Heat Transfer Analysis of Steel Making Process by Using ParticleBased Numerical Simulation

Spray cooling is often used in the steel manufacturing process, and the steel plate temperature at the time of manufacture affects productivity and quality. Therefore, the spray heat transfer coefficient estimation becomes important when determining manufacturing conditions or when designing manufacturing facilities. The conventional heat transfer coefficient estimation method is obtained by reversely analyzing the temperature of the steel plate when the heated steel plate is cooled by a single nozzle used or an experimental device simulating a real machine manufacturing facility. However, in actual equipment manufacturing facilities, it is difficult to grasp the heat transfer and flow state of heat transfer part details due to the presence of rolls, water staying on steel plates, and spray when a large amount of water is injected, heat transfer by numerical calculation Coefficient prediction has been desired. In order to calculate the actual physical phenomena even with a single spray, one hundred million droplets of about hundred micrometer diameter are calculated while resolving a few micrometers of vapor film thickness at the time of collision of the steel plates with droplets, so calculation load is huge.Therefore, the authors describe the heat transfer coefficient of the experimental results as a function of the collision pressure because the vapor film is broken and the heat transfer is promoted if the collision pressure of the spray droplets to the steel plate is high [1]. The heat transfer coefficient was calculated by substituting the collision pressure obtained by the numerical calculation into the experimental formula. The behavior of the spray cooling water includes a complex free interface, but can be calculated by the MPS method, and there is an example [2] where the flow rate of the spray cooling water between rolls of a real steel facility is calculated. In the present examination, the MPS method was similarly used for the prediction of the spray collision pressure, and the calculated particle diameter was also set to 3 mm as in the case [2]. As a result of examination, the particles were injected from the spray outlet so as to match the actual water density, and the actual droplet size was matched with the actual collision pressure

Rapidly expanding spin-polarized exciton halo in a two-dimensional halide perovskite at room temperature

二次元層状ペロブスカイトにおける励起子スピンの特異な空間ダイナミクスの発見 --新たな室温光スピンデバイスの開発に期待--. 京都大学プレスリリース. 2022-08-01.Monitoring of the spatially resolved exciton spin dynamics in two-dimensional semiconductors has revealed the formation of a spatial pattern and long-range transport of the spin-polarized excitons, which holds promise for exciton-based spin-optoelectronic applications. However, the spatial evolution has been restricted to cryogenic temperatures because of the short exciton spin relaxation times at room temperature. Here, we report that two-dimensional halide perovskites can overcome this limitation owing to their relatively long exciton spin relaxation times and substantial exciton-exciton interactions. We demonstrate the emergence of a halo-like spatial profile in spin-polarized exciton population and its ultrafast expansion at room temperature by performing time-resolved Faraday rotation imaging of spin-polarized excitons in two-dimensional perovskite (C₄H₉NH₃)₂(CH₃NH₃)₃Pb₄I₁₃. Exciton-exciton exchange interactions induce density-dependent nonlinear relaxation and ultrafast transport of exciton spins and give rise to a rapidly expanding halo-like spatial pattern. The density-dependent spatial control suggests the potential of using two-dimensional halide perovskites for spin-optoelectronic applications