11,094 research outputs found
Investigation of Dual Coil Induction Heating for Enhanced Temperature Distribution Optimization
AuthorsOptimizing temperature distribution is one of the crucial tasks in induction heating technology, especially, for small devices with constraints on compactness, efficiency, and cost. The traditional coil shape optimization cannot provide a satisfactory solution with highly limited structural constraints of lateral or vertical size. A multi-coil system where each set of coils is fed by multiple inverters enables control of the magnitude and phase of exciting currents so it can be an alternative approach to enhance the design flexibility. However, additional inverters increase both the volume of a driving circuit and the cost of products, so this approach has a risk of reducing applicability to personal electronics. This article proposed a dual coil system, consisting of primary and secondary coils, to enhance the flexibility for temperature distribution optimization. The impact of primary and secondary coil currents on heat source distribution and efficiency are analyzed, and an equivalent circuit model representing both coils and a workpiece is introduced to provide the main concept of the proposed dual coil system. Resonance characteristics of the dual coil system are studied for a sensitivity analysis of design parameters Finally, the optimization flow is proposed and applied to a case study model to demonstrate its superiority compared to the traditional coil design. Potential challenges are discussed to provide insights for further model development
Molecular and genetic characterization of OSH6 (Oryza sativa Homeobox 6) using dissociation (Ds) insertion mutant rice
Genetic studies of dissociation (Ds) insertion mutant rice plants indicated that ectopic expression of truncated OSH6 (Oryza sativa Homeobox 6) mRNA may be responsible for the mutant phenotype of knotted leaf formation at the peduncle. Additionally, ectopic expression of truncated OSH6 mRNA in the OSH6-Ds mutant plant led to alteration of other homeobox genes including OSH15 in leaf tissues. The OSH6-Ds mutant plant exhibited altered expression of more than 118 genes on a 22K rice microarray in comparison with wild type plants. Of these genes, 20 were up- or down-regulated in both OSH6-Ds and OSH6-overexpressing (OSH6-35S) plants. Especially, OsDof3 was not expressed in floral organs, but was present in the panicles of both OSH6-Ds and OSH6-35S plants. It is assumed that truncated OSH6 transcript might be actively involved in the gene expression during organ development. The genetic relationship between OSH6-Ds and OSH15 suggested that the formation of the extra leaf is independent of OSH6-Ds or OSH15 expression. These results suggest that truncated OSH6 mRNA influences lateral organ growth and development by regulating the expression of specific gene groups.Key words: Oryza sativa Homeobox 6 (OSH6) genes, Ds insertion lines, OSH15 mutant
High Quality Bioreplication of Intricate nanostructures from a Fragile Gecko Skin Surface with Bactericidal Properties
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Remote Detection of Radioactive Material using High-Power Pulsed Electromagnetic Radiation
Remote detection of radioactive materials is impossible when the measurement location is far from the radioactive source such that the leakage of high-energy photons or electrons from the source cannot be measured. Current technologies are less effective in this respect because they only allow the detection at distances to which the high-energy photons or electrons can reach the detector. Here we demonstrate an experimental method for remote detection of radioactive materials by inducing plasma breakdown with the high-power pulsed electromagnetic waves. Measurements of the plasma formation time and its dispersion lead to enhanced detection sensitivity compared to the theoretically predicted one based only on the plasma on and off phenomena. We show that lower power of the incident electromagnetic wave is sufficient for plasma breakdown in atmospheric-pressure air and the elimination of the statistical distribution is possible in the presence of radioactive material.ope
Seroprevalence of Hepatitis B, C and D in Vietnam: A systematic review and meta-analysis.
Background: Vietnam has one of the greatest disease burdens from chronic viral hepatitis. Comprehensive prevalence data are essential to support its elimination as a public health threat. Methods: We searched Medline and Embase from 1990 to 2021 for seroprevalence data relating to Hepatitis B (HBV), C (HCV) and D (HDV) in Vietnam. We estimated pooled prevalence with a DerSimonian-Laird random-effects model and stratified study populations into i) low-risk ii) high-risk exposure and iii) liver disease. We further estimated prevalence by decade and region and rates of HIV-coinfection. Findings: We analysed 72 studies, including 120 HBV, 114 HCV and 23 HDV study populations. Pooled HBV prevalence was low in blood donors (1.86% [1.82-1.90]) but high in antenatal populations (10.8% [10.1-11.6]) and adults in the general population (10.5% [10.0-11.0]). It was similar or modestly increased in groups at highest risk of exposure, suggesting the epidemic is largely driven by chronic infections acquired in childhood. HCV pooled prevalence in the general population was lower than historical estimates: 0.26% (0.09-0.51) have active infection defined by detectable antigen or HCV RNA. In contrast, there is an extremely high prevalence of active HCV infection in people who inject drugs (PWID) (57.8% [56.5-59.1]), which has persisted through the decades despite harm-reduction interventions. HDV appears mainly confined to high-risk groups. Interpretation: Blood safety has improved, but renewed focus on HBV vaccination at birth and targeted HCV screening and treatment of PWID are urgently required to meet elimination targets. Large cross-sectional studies are needed to better characterize HDV prevalence, but mass screening may not be warranted. Funding: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors
Delivery of sTRAIL variants by MSCs in combination with cytotoxic drug treatment leads to p53-independent enhanced antitumor effects
Mesenchymal stem cells (MSCs) are able to infiltrate tumor tissues and thereby effectively deliver gene therapeutic payloads. Here, we engineered murine MSCs (mMSCs) to express a secreted form of the TNF-related apoptosis-inducing ligand (TRAIL), which is a potent inducer of apoptosis in tumor cells, and tested these MSCs, termed MSC.sTRAIL, in combination with conventional chemotherapeutic drug treatment in colon cancer models. When we pretreated human colorectal cancer HCT116 cells with low doses of 5-fluorouracil (5-FU) and added MSC.sTRAIL, we found significantly increased apoptosis as compared with single-agent treatment. Moreover, HCT116 xenografts, which were cotreated with 5-FU and systemically delivered MSC.sTRAIL, went into remission. Noteworthy, this effect was protein 53 (p53) independent and was mediated by TRAIL-receptor 2 (TRAIL-R2) upregulation, demonstrating the applicability of this approach in p53-defective tumors. Consequently, when we generated MSCs that secreted TRAIL-R2-specific variants of soluble TRAIL (sTRAIL), we found that such engineered MSCs, labeled MSC.sTRAIL DR5, had enhanced antitumor activity in combination with 5-FU when compared with MSC.sTRAIL. In contrast, TRAIL-resistant pancreatic carcinoma PancTu1 cells responded better to MSC.sTRAIL DR4 when the antiapoptotic protein XIAP (X-linked inhibitor of apoptosis protein) was silenced concomitantly. Taken together, our results demonstrate that TRAIL-receptor selective variants can potentially enhance the therapeutic efficacy of MSC-delivered TRAIL as part of individualized and tumor-specific combination treatments. © 2013 Macmillan Publishers Limited All rights reserved
Prevalence and predictors of video game addiction: a study based on a national representative sample of gamers
Video gaming has become a popular leisure activity in many parts of the world, and an increasing number of empirical studies examine the small minority that appears to develop problems as a result of excessive gaming. This study investigated prevalence rates and predictors of video game addiction in a sample of gamers, randomly selected from the National Population Registry of Norway (N =3389). Results showed there were 1.4 % addicted gamers, 7.3 % problem gamers, 3.9 % engaged gamers, and 87.4 % normal gamers. Gender (being male) and age group (being young) were positively associated with addicted-, problem-, and engaged gamers. Place of birth (Africa, Asia, South- and Middle America) were positively associated with addicted- and problem gamers. Video game addiction was negatively associated with conscientiousness and positively associated with neuroticism. Poor psychosomatic health was positively associated with problem- and engaged gaming. These factors provide insight into the field of video game addiction, and may help to provide guidance as to how individuals that are at risk of becoming addicted gamers can be identified
Superconformal indices of three-dimensional theories related by mirror symmetry
Recently, Kim and Imamura and Yokoyama derived an exact formula for
superconformal indices in three-dimensional field theories. Using their
results, we prove analytically the equality of superconformal indices in some
U(1)-gauge group theories related by the mirror symmetry. The proofs are based
on the well known identities of the theory of -special functions. We also
suggest the general index formula taking into account the global
symmetry present for abelian theories.Comment: 17 pages; minor change
Vertically aligned Si intrananowire p-n diodes by large-area epitaxial growth
We demonstrate fabrication of vertically aligned, intrananowire p-n diodes by large-area epitaxial growth of Si nanowires (NWs). The axially modulated doping profile of p-n junctions is achieved by in situ doping with alternating addition of dopants in the axial sequence during Au-assisted chemical vapor deposition. We provide direct evidence of the intra-NW p-n junctions using scanning local probes in both individual NWs and vertically aligned NWs at large areas. Our study suggests implication for integrated electronics and optoelectronics based on bottom-up Si NWs.open11910Nscopu
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