Multiscale analysis of piezoelectric material by using EBSD-measured realistic model

Material properties of a polycrystal piezoelectric ceramic, a barium titanate BaTiO3, were analyzed by the two-scale crystallographic homogenization method. Threedimensional (3-D) micro-finite element (FE) model was constructed based on the electron backscatter diffraction (EBSD) measured crystal orientation distribution images. The images are piled up to a 3-D voxel data of crystal orientation distribution by repeating mechanically and chemically polishing, and EBSD measurement of the ceramic. We obtained 13 EBSD images of 128×100 pixels, which measurement interval was 0.635μm in-plane and the average amount of polishing was 1.66μm in thickness (normal) direction of specimen. Each voxel of EBSD was assigned into 8-node solid FE in-plane with maintaining resolution of EBSD measurement, and was divided into three FEs along thickness direction with same crystal orientation, because of improvement of aspect ratio of FE. The total number of FEs was 499,200 (=128×100×13×3) which corresponded to over two millions degrees of freedom. In order to realize a large-scale micro-analysis using EBSD-measured voxel FE model, the coupled problem of the piezoelectric material was solved by parallel conjugate gradient (CG) method combined with the block Gauss-Seidel (BGS) method. The coupled micro-FE equation to obtain characteristic function vectors was separated into two linear equations, such as the elastic deformation and electrostatic analyses, by employing the BGS method, and then the equations were solved by the parallel CG solver while substituting coupling terms each other. Therefore, nested iterative scheme was constructed on a PC cluster. In addition, the representative volume element (RVE) size was determined based on the orientation distribution function analyses of EBSD voxel data. The least RVE size was 25,000μm3, which corresponded to include 150 crystal grains

A new crystal plasticity constitutive equation based on crystallographic misorientation theory

Since plastic deformation of polycrystal sheet metal is greatly affected by its initial and plastic deformed textures, multi-scale finite element (FE) analysis based on homogenization with considering micro-polycrystal morphology is required [1]. We formulated a new crystal plasticity constitutive equation to introduce not only the effect of crystal orientation distribution, but also the size of crystal grain and/or the effect of crystal grain boundary for the micro-FE analysis. The hardening evolution equation based on strain gradient theory [2], [3] was modified to introduce curvature of crystal orientation based on crystallographic misorientation theory. We employed two-scale structure, such as a microscopic polycrystal structure and a macroscopic elastic/plastic continuum. Our analysis code predicts the plastic deformation of polycrystal metal in the macro-scale, and simultaneously the crystal texture and misorientation evolutions in the micro-scale. In this study, we try to reveal the relationship between the plastic deformation and the microscopic crystal misorientation evolution by using the homogenized FE procedure with the proposed crystal plasticity constitutive equation. The crystallographic misorientation evolution, which affects on the plastic deformation of FCC polycrystal metal, was investigated by using the multi-scale FE analysis. We confirmed the availability of our analysis code employing the new constitutive equation through the comparison of a uniaxial tensile problem with the numerical result and the experimental one

Morphological and Histopathological Changes in Orofacial Structures of Experimentally Developed Acromegaly-Like Rats: An Overview

Tongue enlargement and mandibular prognathism are clinically recognized in almost all patients with acromegaly. An acromegaly-like rat model recently developed by exogenous administration of insulin-like growth factor I (IGF-I) was used to investigate morphological and histopathological changes in orofacial structures and to clarify whether these changes were reversible. Exogenous administration of IGF-I evoked specific enlargement of the tongue with identifiable histopathological changes (increased muscle bundle width, increased space between muscle bundles, and increased epithelial thickness), elongation of the mandibular alveolar bone and ascending ramus, and lateral expansion of the mandibular dental arch. Regarding histopathological changes in the mandibular condyle, the cartilaginous layer width, bone matrix ratio, and number of osteoblasts were all significantly greater in this rat model. After normalization of the circulating IGF-I level, tongue enlargement and histopathological changes in the tongue and mandibular condyle were reversible, whereas morphological skeletal changes in the mandible remained

Tumor Shrinkage in Response to Vitamin K2 in Hepatocellular Carcinoma with Multiple Lung Metastases: A Case Report

Introduction: Advanced or metastatic hepatocellular carcinoma (HCC) can be lethal because of the limited therapeutic approach such as sorafenib. Recently, Vitamin K2 (VK2) has been increasingly recognized to have anti-cancer effects for HCC in vitro and vivo. However, the direct anti-cancer effect of VK2 to HCC has not been established yet in human.Presentation of Case: We presented here a 88-year-HCC patient displayed a tumor shrinkage in response to VK2 in multiple lung metastases, indicating the possibility of VK2 as an anti-cancer agent in human. Menatetrenone, a VK2 analogue, was introduced for multiple lung metastases as a palliative treatment, and thereafter multiple lung metastases, except one lung lesion, displayed tumor shrinkage and disappeared within five months after VK2 intake. The residual one lesion continued to grow up during the intake of VK2, suggesting that the residual tumor was insensitive to VK2 represented by tumor heterogeneity. Consequently, after a radiation therapy for the residual lesion, the elevated tumor markers of all were finally decreased into normal levels, and he is still alive for 18 months after VK2 intake without elevated tumor marker levels and toxic adverse effects.Conclusion:VK2 may be a therapeutic option for advanced and metastatic HCCs without any toxic adverse

Via-switch FPGA with transistor-free programmability enabling energy-efficient near-memory parallel computation

We are developing field-programmable gate arrays (FPGAs) with a new non-volatile switch called via-switch. In via-switch FPGAs (VS-FPGAs), the via-switches required for reconfiguration are placed in the routing layer so that the entire transistor layer can be utilized for computing, and higher implementation density can be achieved compared to conventional SRAM FPGAs. Furthermore, since arithmetic units and memories for computing can be placed under the via-switch crossbar for routing, large-scale parallel operations can be realized where the memory and the arithmetic unit are adjacent to each other. These features enable operation with high energy efficiency. This article reports 65 nm prototype fabrication results and predicted the performance of the VS-FPGA designed for AI applications. We also present the developed application mapping flow and crossbar programming method. The VS-FPGA closes the gap between FPGA and application-specific integrated circuits (ASIC) with the performance advantage of the via-switch and via-switch copy scheme for FPGA-to-ASIC migration, contributing to the expansion of the FPGA usage

Daikenchuto accelerates the recovery from prolonged postoperative ileus after open abdominal surgery : a subgroup analysis of three randomized controlled trials

Purpose Prolonged postoperative ileus (POI) is a common complication after open abdominal surgery (OAS). Daikenchuto (DKT), a traditional Japanese medicine that peripherally stimulates the neurogenic pathway, is used to treat prolonged POI in Japan. To analyze whether DKT accelerates the recovery from prolonged POI after OAS, we conducted a secondary analysis of three multicenter randomized controlled trials (RCTs). Methods A secondary analysis of the three RCTs supported by the Japanese Foundation for Multidisciplinary Treatment of Cancer (project numbers 39-0902, 40-1001, 42-1002) assessing the effect of DKT on prolonged POI in patients who had undergone OAS for colon, liver, or gastric cancer was performed. The subgroup included 410 patients with no bowel movement (BM) before the first diet, a DKT group (n = 214), and a placebo group (n = 196). Patients received either 5 g DKT or a placebo orally, three times a day. The primary endpoint was defined as the time from the end of surgery to the first bowel movement (FBM). A sensitivity analysis was also performed on the age, body mass index and dosage as subgroup analyses. Results The primary endpoint was significantly accelerated in the DKT group compared with the placebo group (p = 0.004; hazard ratio 1.337). The median time to the FBM was 113.8 h in the placebo group and 99.1 h in the DKT treatment group. Conclusions The subgroup analysis showed that DKT significantly accelerated the recovery from prolonged POI following OAS

Low-lying states of 56 Fe

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Generation of electromagnetic waves from 0.3 to 1.6 terahertz with a high-T-c superconducting Bi2Sr2CaCu2O8+delta intrinsic Josephson junction emitter

To obtain higher power P and frequency f emissions from the intrinsic Josephson junctions in a high-T-c superconducting Bi2Sr2CaCu2O8+delta single crystal, we embedded a rectangular stand-alone mesa of that material in a sandwich structure to allow for efficient heat exhaust. By varying the current-voltage (I-V) bias conditions and the bath temperature T-b, f is tunable from 0.3 to 1.6 THz. The maximum P of a few tens of mu W, an order of magnitude greater than from previous devices, was found at T-b similar to 55K on an inner I-V branch at the TM(1,0) cavity resonance mode frequency. The highest f of 1.6 THz was found at T-b = 10K on an inner I-V branch, but away from cavity resonance frequencies. A possible explanation is presented