ROHM

Abstract Fusion by Advanced Superconducting Tokamak (FAST) is a project being proposed as a facility for R&D, testing, and demonstration of systems integration for a deuterium–tritium (DT) fusion energy reactor. The required specifications for FAST are: DT fusion power of 50– 100 MW , neutron wall loading of 0.3– 1 MWm − 2 , discharge duration of 1000 s, and full-power operation lifetime of 1000 h. A quasi-zero-dimensional parameter survey has been carried out to find the parameter region necessary to satisfy the above specifications with the minimum device cost. It was found that a low aspect ratio ( A ∼ 2.3 ), compact (major radius ∼ 2.0 m ) tokamak with high temperature superconductor magnets and neutral beam injection power of about 50 MW (with the energy of 500 keV) offers a possible design point. A time-dependent transport analysis was performed to confirm accessibility to such an operating point and to evaluate the required flux swing for the central solenoid.

We optimized the field plate resistance R<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">s</inf> for 40V trench field plate MOSFET. Several types of chips were made with different trench lengths and contact positions, and losses were confirmed by a double-pulse test. Previous studies have shown that dynamic avalanche breakdown occurs when R<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">s</inf> is large, and large ringing occurs when R<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">s</inf> is small. By defining and calculating the switching loss until the end of ringing, it was found that there is an R<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">s</inf> with the smallest switching loss. The same verification was also performed for gate resistance RG. It is known that self-turn-on occurs when the gate trench is long. As with the verification for Rs, it was found that there is an RG that minimizes switching loss. In addition, as another method of lowering Rs, the same verification was performed for an alternating device in which the gate electrode is used as a source potential every other time. By changing the external RG and comparing it with the total loss, we found that it is advantageous to have a normal device when the external RG is small, and an alternating device when it is large. By changing the reticle used in the contact layer to change the connection ratio of the upper electrode, it is possible to support various applications and contribute to improving efficiency.

Background: Hepatitis B virus (HBV) is a major cause of morbidity and mortality globally, and chronic infections are associated with cirrhosis and hepatocellular carcinoma. Issues with conventional treatments and vaccines mean there is a need for new therapeutic vaccines, which must elicit a strong and sustainable immune response. Here, we evaluated the immunogenicity of dual-antigen vaccines containing hybrid surface (hy-LHBs) and core (HBc) antigens, combined with a carboxyl-vinyl polymer (CVP) as a mucoadhesive excipient, following intranasal administration in mice. Methods: Mice were intranasally administered a mixed vaccine (10 µg of hy-LHBs and 2.5 or 10 µg of HBc) with or without a CVP excipient, and they were assessed for their immune response (levels of IgGs or IgA antibodies in an ELISA, IFN-γ level in splenocytes in an ELISpot assay, and cytokine/chemokine levels in a BioPlex assay). A protein stability assay was also conducted for vaccine formulations with and without excipients. Results: Significantly enhanced IgG production was noted targeting hy-LHBs and (less markedly) HBc at 10 µg/antigen, but only a non-significant elevation was noted with the vaccine containing 2.5 µg HBc. The BioPlex assay showed a significant increase in IL-2 (#00-07, 0B), IL-12(p40)(#00), eotaxin (#00), MIP1α (#00, #00-07, 0B), and MCP-1 (#00-07, 0B) in mice that received treatment compared to those of untreated mice. The endpoint titers of IgG1 and IgG2a were measured, which were higher with CVP excipients than without. From the IgG2a/IgG1 ratio, a higher IgG1 response was induced by CVPs to hy-LHBs and a higher IgG2a response was induced to HBc. Th2-dominant phenotype to hy-LHBs was induced with CVP#00 in an ELISpot assay. The highest anti-hy-LHBs antibody titer was noted with the conventional CVP#00 excipient. Consistent with these results, a higher amount of neutralizing antibodies of HBV was induced with CVP#00 treatment and followed by #00-03 and #14-00. Conclusions: We consider that the addition of CVP excipients to vaccine formulation enhances immunogenicity and HBV antigen stability for intranasal vaccines. This effect was seen for both humoral and cell-mediated immune responses, indicating the potential of CVPs as excipients in intranasal HBV vaccines.

This paper investigates the influence of silica fillers on the tensile mechanical properties of epoxy molding compound (EMC) by uniaxial tensile testing at room temperature. We adopted two kinds of EMC dog-bone shaped specimens containing silica fillers with 0 wt% <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(\mathbf{EMC}^{\mathbf{0}\mathbf{wt}\%})$</tex> and 65 wt% <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(\mathbf{EMC}^{\mathbf{65}\mathbf{wt}\%})$</tex>. The stress-strain <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(\boldsymbol{S}-\boldsymbol{S})$</tex> curves showed that <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{EMC}^{\mathbf{0}\mathbf{wt}\%}$</tex> is ductile and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{EMC}^{\mathbf{65}\mathbf{wt}\%}$</tex> is brittle. Notably, the Young's modulus of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{EMC}^{\mathbf{0}\mathbf{wt}\%}$</tex> ‘ is smaller than that of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{EMC}^{\mathbf{65}\mathbf{wt}\%}$</tex>, but the tensile strength of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{EMC}^{\mathbf{0}\mathbf{wt}\%}$</tex> ‘ was about 25 % higher than that of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{EMC}^{\mathbf{65}\mathbf{wt}\%}$</tex> ‘. This fracture behavior was caused by the local stress concentration around the silica fillers as suggested by the finite element analysis. The scanning electron microscopy observation of the fracture surfaces also supported this view.

The use of power modules with multiple SiC-MOSFETs dies connected in parallel has increased significantly for traction inverter circuits in electric vehicles(xEVs). However, this configuration can cause problems with oscillation between the parallel-connected dies. This study proposes a module design method to suppress the oscillation. This design method is based on the approximate open-loop transfer function between the parallel-connected dies. The validity of the proposed design method was confirmed through simulations and experimental evaluations.

The Centers for Disease Control and Prevention created the Social Vulnerability Index (SVI) for the purpose of allocating resources in times of emergency based on social determinants of health (SDOH). The purpose of this systematic review was to evaluate how the SVI tool has been applied in health care literature focused on health in the United States (US). A systematic literature review was conducted in 7 research databases with an 11-year time frame reflecting the launch of SVI, with the last search completed on September 29, 2022. Studies were included that involved humans, health, SVI, and conducted in the US. Articles were excluded if the SVI was used in COVID-19, disaster, pandemic, environment, or hazards. A total of 47 articles were included in the systematic review. The majority of studies analyzed individual/population health outcomes in clinical, surgical, mortality, or health promotion areas. The majority of studies showed a relationship between neighborhood-level SDOH and health outcomes. Study authors reported strengths, limitations, and recommendations of the SVI tool. A potential limitation of the study was the exclusion of studies that used the SVI related to disaster. The SVI represents a powerful tool to assess neighborhood-level SDOH and examine upstream drivers health outcomes with direct implications for research, policy, and practice.

Digital technologies are rapidly prevailing in our society, and there the performance of analog circuits is progressing and their market amount is growing steadily. We have experienced that in many cases analog parts may be small compared to digital ones, but analog ones are troublesome. Testing of analog circuits plays a crucial role in achieving both reliability and low cost such as in computer, Internet, AI, IoT and automotive systems. Also, in ATE systems, analog parts are key. Analog testing is a challenge including circuit design, signal processing algorithms and measurement methods/systems.This session will discuss analog testing related issues with three talks by researchers from industry. The first talk introduces a state-of-art low jitter 1GHz crystal oscillator by an ATE manufacturer. The second one explains a time measurement BOST using a successive approximation register time-to-digital converter (SAR TDC) with fine resolution by a semiconductor company. The third one is a proposal of an ADC diagnosis method using obtained self-calibration parameters, by an ADC design researcher.

An n-legged inverter for driving n−1 transmitter coils has been proposed to reduce the implementation costs of wireless power transfer (WPT) systems for the dynamic charging of electric vehicles (EVs). However, leakage current flowing through uncoupled coils deteriorates system efficiency and causes leakage electromagnetic interference (EMI). Suppression of leakage current by switching of legs not directly used for wireless charging is preferable as it requires no additional components. However, turning the unused legs off can be insufficient, while switching them identically to adjacent legs causes large switching losses and is potentially counterproductive. A novel switching method of unused legs is proposed to greatly suppress leakage current with limited losses.

This article investigates the degradation mechanism of sintered silver (s-Ag) layer in silicon carbide (SiC) die attach by means of thermal shocked test (TST) and nine-point bending test (NBT). TST can thermally provide out-of-plane deformation with s-Ag die layer, whereas NBT developed by the authors can mechanically provide the out-of-plane deformation. Two types of Ag paste (NP: nanopaste and NMP: nano- and micropaste) are employed, which are sintered with 300 °C for 10 min under 60-MPa pressure for SiC die attach. TSTs are conducted under thermal cyclic loading between −40 °C and 150 °C with trapezoidal waveform for 60 min per a cycle. NBTs are conducted under cyclic mechanical loading between 0 and 300 N with triangle waveform for 3 min per a cycle at 150 °C. Scanning acoustic tomography (SAT) evaluates the die-attach delamination during TST and NBT, which starts from the edge of the die. Cross-sectional scanning electron microscopy (SEM) observation demonstrates that mechanical cracking and material aging in s-Ag layer coexist after TST under the −40 °C to 150 °C conditions only. A damage parameter (DP) proposed in this study works well to fit the delamination area ratio in the cracking and cracking-aging specimens separately after 1000 cycles. Molecular dynamics (MD) simulation and classical pore growth discussion suggest that pores can grow under only tensile stress state at high temperature, which would have given rise to the difference between the two degradation mechanisms.