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

X-ray study of ferroic octupole order producing anomalous Hall effect

放射光でついに見えた磁気オクタポール --熱を電気に変える新たな担い手--. 京都大学プレスリリース. 2021-09-27.Recently found anomalous Hall, Nernst, magnetooptical Kerr, and spin Hall effects in the antiferromagnets Mn₃X (X = Sn, Ge) are attracting much attention for spintronics and energy harvesting. Since these materials are antiferromagnets, the origin of these functionalities is expected to be different from that of conventional ferromagnets. Here, we report the observation of ferroic order of magnetic octupole in Mn₃Sn by X-ray magnetic circular dichroism, which is only predicted theoretically so far. The observed signals are clearly decoupled with the behaviors of uniform magnetization, indicating that the present X-ray magnetic circular dichroism is not arising from the conventional magnetization. We have found that the appearance of this anomalous signal coincides with the time reversal symmetry broken cluster magnetic octupole order. Our study demonstrates that the exotic material functionalities are closely related to the multipole order, which can produce unconventional cross correlation functionalities

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

Synchronized Collapse and Formation of Long-Period Stacking and Chemical Orders in Mg85Zn6Y9\mathrm{Mg_{85}Zn_6Y_9}

Long period stacking ordered (LPSO) structures that are synchronized with the chemical order in Mg–TM (transition metal)–RE (rare earth) systems have received special attention as a new type of strengthening phase for Mg alloys. For example, the rapidly solidified powder metallurgy alloy $Mg_{97}Zn_{1}Y_{2}$ with an LPSO phase has a yield strength exceeding 600 MPa [1], while the cast $Mg_{97}Zn_{1}Y_{2}$ alloy with an LPSO phase produced using a hot extrusion process has a yield strength exceeding 350 MPa, which is sufficient for use in many components for airplanes and automobiles [2].The crystalline structures of the LPSO phases in Mg–TM–RE systems have been reported by many researchers [3], [4], [5] and [6], and four types of LPSO phases (10H, 14H, 18R, and 24R) have been reported. The hexagonal ABAB… stacking sequence is changed due to the incorporation of TM and RE concentrate layers. As a result, long period stacking orders are formed along the c axis. Accordingly, rhombohedral (R) and hexagonal (H) Bravais lattices occur, depending on the stacking period of the hcp stacking layer [6].Furthermore, based on scanning transmission and transmission electron microscopy (STEM and TEM, respectively) observations for Mg-Al-Gd alloy, the existence of in-plane ordering has been proposed by Yokobayashi et al. [7]. They found that $L1_{2}-type$ ordered clusters were regularly aligned in the segregated layer. Recently, Egusa et al. revised the crystalline structure models for the 18R- and 14H-type LPSOs of Mg–Zn–Y taking into consideration the in-plane order resulting from the alignment of the $L1_{2}-type$ cluster in the Zn–Y segregated layers [8]. Yamasaki et al. also proposed a 10H-type LPSO crystalline structure in a Mg–Zn–Y alloy [9]. Schematic diagrams of the stacking and in-plane ordering of the 18R-type LPSOs are shown in Fig. 1

D03\mathrm{D0_{3}}+hcp mixed phase with nanostructures in Mg85Zn6Y9\mathrm{Mg_{85}Zn_{6}Y_{9}} alloy obtained by high-pressure and high-temperature treatments

High pressure and high temperature state of long period stacking order structure (LPSO) synchronized with chemical concentration in Mg$_{85}$Zn$_{6}$Y$_{9}$ alloy have been investigated. A stripe-patterned nanostructure consisting of D0$_{3}$ and hcp phases is formed in Mg$_{85}$Zn$_{6}$Y$_{9}$ alloy by high pressure and high temperature treatments. The nanostripe patterns are created by the phase separation of LPSO synchronized with chemical concentration. A pressure–temperature phase diagram is given in this research. LPSO is stable below 673 K, the D0$_{3}$+hcp mixed phase dominant above 973 K under the pressure up to 20 GPa. Phase separation under high pressure is useful for the fabrication of nanostructured metallic materials

Th17-Dependent Nasal Hyperresponsiveness Is Mitigated by Steroid Treatment

Th17 cells are implicated in allergic inflammatory diseases, including allergic rhinitis (AR), though the effect of steroids on Th17 cell-dependent nasal responses is unclear. Herein, we investigated a nasal inflammation model elicited by allergen provocation in mice infused with Th17 cells and its responsiveness against steroid treatment. We transferred BALB/c mice with Th17 cells, which were differentiated in vitro and showed a specific reaction to ovalbumin (OVA). We challenged the transferred mice by intranasal injection of OVA and to some of them, administered dexamethasone (Dex) subcutaneously in advance. Then, we assessed immediate nasal response (INR), nasal hyperresponsiveness (NHR), and inflammatory cell infiltration into the nasal mucosa. The significant nasal inflammatory responses with massive neutrophil accumulation, INR, and NHR were induced upon allergen challenge. Allergen-induced INR and NHR were significantly suppressed by Dex treatment. This study suggested the effectiveness of steroids on Th17 cell-mediated nasal responses in AR

Overexpression/enhanced kinase activity of BCR/ABL and altered expression of Notch1 induced acute leukemia in p210BCR/ABL transgenic mice

Chronic myelogenous leukemia (CML) is a hematopoietic disorder, which begins as indolent chronic phase but inevitably progresses to fatal blast crisis. p210BCR/ABL, a constitutively active tyrosine kinase, is responsible for disease initiation but molecular mechanism(s) underlying disease evolution remains largely unknown. To explore this process, we employed retroviral insertional mutagenesis to CML-exhibiting p210BCR/ABL transgenic mice (Tg). Virus infection induced acute lymphoblastic leukemia (ALL) in p210BCR/ABL Tg with a higher frequency and in a shorter latency than wild-type littermates, and inverse PCR detected two retrovirus common integration sites (CISs) in p210BCR/ABL Tg tumors. Interestingly, one CIS was the transgene itself, where retrovirus integrations induced upregulation of p210BCR/ABL and production of truncated BCR/ABL with an enhanced kinase activity. Another CIS was Notch1 gene, where retrovirus integrations resulted in overexpression of Notch1 and generation of Notch1 lacking the C-terminal region (Notch1C) associated with stable expression of its activated product, C-terminus-truncated Notch intracellular domain (NICDC). In addition, generation of Tg for both p210BCR/ABL and Notch1C developed ALL in a shortened period with Stat5 activation, demonstrating the cooperative oncogenicity of Notch1C/NICDC with p210BCR/ABL involving Stat5-mediated pathway. These results demonstrated that overexpression/enhanced kinase activity of BCR/ABL and altered expression of Notch1 induce acute leukemia in a transgenic model for CML