5,858 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
Modulation of hole-injection in GaInN-light emitting triodes and its effect on carrier recombination behavior
The effects of the hole injection modulated by using a three-terminal GaInN-based light emitter, light-emitting triode (LET), on carrier recombination behavior and efficiency droop are investigated. It was found that the lateral electric field created by applying voltage bias between the two anodes effectively reduces efficiency droop as well as dynamic conductance of LETs. Detailed analyses of LETs under various operation conditions by APSYS simulations reveal that the asymmetry in carrier transport between electrons and holes is alleviated by promoted injection of hot holes over the potential barrier, increasing the hole concentration as well as the radiative recombination rate in the multiple quantum well active region. (C) 2015 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.110Ysciescopu
Role of hydrogen carrier gas on the growth of few layer hexagonal boron nitrides by metal-organic chemical vapor deposition
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Biological Control of Stem Canker in Red-Fleshed Dragon Fruit (Hylocereus polyrhizus) by Emulsion Formulation of Trichoderma asperelloides PSU-P1
Master of Science (Plant Pathology), 2023Stem canker of red-fleshed dragon fruit (Hylocereus polyrhizus) was observed on dragon fruit plantation field in Phatthalung province, southern Thailand. The disease samples were collected and isolated by tissue transplanting method. Pathogenicity was conducted on healthy cladodes of dragon fruits by agar plug method and revealed the fungal isolate PSU-SC02 caused stem canker on cladodes of H. polyrhizus. Fungal isolate PSU-SC02 was identified based on morphology and molecular properties of double DNA sequences of internal transcribed spacer (ITS) and β-tubulin (tub) as Neoscytalidium dimidiatum.
Biological control by Trichoderma species are widely used to control several plant diseases. However, environmental conditions affect bio-control agent in the field, development of appropriate formulation is an alternative way to solve this problem. This research aimed to develop a new Trichoderma asperelloides PSU-P1 formulation that would be more effective against N. dimidiatum. Three vegetable oils, two emulsifier-dispersing agents (Tween 20 and Tween 80) and one source of carbon (dextrose) were tested for carrier additive. Viability and antifungal ability of formulation incubated at ambient temperature and at cool temperature (10oC) were compared. A total of 12 emulsions based was tested for viscosity by evaluating the mixing time. The formulation composed of coconut oil, DW and tween 20 in a ratio of 30:60:10, respectively, showed the great mixing time of 1.14 min significantly lower than that of other formulations (p<0.05).
Application of this formulation suppressed canker development with 0.53 cm2 symptom area compared with control (pathogen alone) 1.65 cm2. Viability of T. asperelloides PSU-P1 conidia was observed by percentage of surface area in PDA plates at day 3, whereas percentage inhibition was observed on colony radii of N. dimidiatum. Viability of this formulation stored at ambient temperature showed percentage of surface area of T. asperelloides PSU-P1 ranged 58.08–100% whereas formulation stored at cool temperature showed 70.59–100%. This formulation effectively inhibited N. dimidiatum in PDA plates with percentage inhibition rage from 50–77% and 54.2–76.19%, respectively in the same manner with viability. This finding suggested that the emulsion formulation developed in this study was appropriated to store T. asperelloides PSU-P1 conidia with high viability and antifungal ability up to 6 months
Rhythmic interaction between Period1 mRNA and HnRNP Q leads to circadian time-dependent translation
The mouse PERIOD1 (mPER1) protein, along with other clock proteins, plays a crucial role in the maintenance of circadian rhythms. mPER1 also provides an important link between the circadian system and the cell cycle system. Here we show that the circadian expression of mPER1 is regulated by rhythmic translational control of mPer1 mRNA together with transcriptional modulation. This time-dependent translation was controlled by an internal ribosomal entry site (IRES) element in the 5' untranslated region (5'-UTR) of mPer1 mRNA along with the trans-acting factor mouse heterogeneous nuclear ribonucleoprotein Q (mhnRNP Q). Knockdown of mhnRNP Q caused a decrease in mPER1 levels and a slight delay in mPER1 expression without changing mRNA levels. The rate of IRES-mediated translation exhibits phase-dependent characteristics through rhythmic interactions between mPer1 mRNA and mhnRNP Q. Here, we demonstrate 5'-UTR-mediated rhythmic mPer1 translation and provide evidence for posttranscriptional regulation of the circadian rhythmicity of core clock genes.X112932sciescopu
Chemical ordering in PtNi nanocrystals
We investigated the chemical ordering in PtNi nanocrystals fabricated on sapphire substrate using in-situ synchrotron X-ray scattering. Nanocrystals with composition close to 1:1 were ordered in the tetragonal L1(0) structure at low temperatures. The transition to disordered FCC structure occurred at around 640 degrees C and substantial hysteresis of about 50 K was observed. Nanocrystals of smaller sizes fabricated under the same conditions were Ni rich and ordered into Cu3Au type L1(2) structure. Significantly higher degree of chemical ordering was observed in L1(2) structure than in L1(0) structure. (C) 2016 Elsevier B.V. All rights reserved.1144Ysciescopu
Kinetic roughening of ion-sputtered Pd(001) surface: Beyond the Kuramoto-Sivashinsky model
The kinetic roughening of Ar+ ion-sputtered Pd(001) surface was investigated. The facet formation on the sputtered surface was studied by tracing the extradiffraction peaks or satellites around the diffraction peaks corresponding to the sample surface. The morphological evolution of the sputtered Pd(001) surface was also investigated by an scanning tunneling microscopy (STM). It was shown that the nanoscale adatom islands form and grow with increasing sputter time.open313
Diseleno[3,2-b:2′,3′-d]selenophene-containing high-mobility conjugated polymer for organic field-effect transistors
KGaA, Weinheim The synthesis of a diseleno[3,2-b:2′,3′-d]selenophene (DSS) composed of three fused selenophenes is reported and it is used as a building block for the preparation of a high hole mobility conjugated polymer (PDSSTV). The polymer demonstrates strong intermolecular interactions even in solution, despite steric repulsion between the large Se atom in DSS and adjacent (C β )–H atoms which leads to a partially twisted confirmation PDSSTV. Nevertheless, 2D grazing incidence X-ray diffraction (2D-GIXD) analysis reveals that the polymer tends to align in a highly ordered edge-on orientation after thermal annealing. The polymer demonstrates promising performance in a field-effect transistor device with saturated hole mobility up to 2 cm 2 V −1 s −1 obtained under relatively low gate voltages of −30 V. The ultilization of a Se-containing fused aromatic system, therefore, appears to be a promising avenue for the development of high-performance conjugated polymers
Water-Repellent TiO₂-Organic Dye-Based Air Filters for Efficient Visible-Light-Activated Photochemical Inactivation against Bioaerosols
Recently, bioaerosols, including the 2019 novel coronavirus, pose a serious threat to global public health. Herein, we introduce a visible-light-activated (VLA) antimicrobial air filter functionalized with titanium dioxide (TiO2)–crystal violet (CV) nanocomposites facilitating abandoned visible light from sunlight or indoor lights. The TiO2–CV based VLA antimicrobial air filters exhibit a potent inactivation rate of ∼99.98% and filtration efficiency of ∼99.9% against various bioaerosols. Under visible-light, the CV is involved in overall inactivation by inducing reactive oxygen species production both directly (CV itself) and indirectly (in combination with TiO2). Moreover, the susceptibility of the CV to humidity was significantly improved by forming a hydrophobic molecular layer on the TiO2 surface, highlighting its potential applicability in real environments such as exhaled or humid air. We believe this work can open a new avenue for designing and realizing practical antimicrobial technology using ubiquitous visible-light energy against the threat of infectious bioaerosols
Template Synthesis of Three-Dimensional Cubic Ordered Mesoporous Carbon With Tunable Pore Sizes
Three-dimensional cubic ordered mesoporous carbons with tunable pore sizes have been synthesized by using cubic Ia3d mesoporous KIT-6 silica as the hard template and boric acid as the pore expanding agent. The prepared ordered mesoporous carbons were characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption–desorption analysis. The results show that the pore sizes of the prepared ordered mesoporous carbons with three-dimensional cubic structure can be regulated in the range of 3.9–9.4 nm. A simplified model was proposed to analyze the tailored pore sizes of the prepared ordered mesoporous carbons on the basis of the structural parameters of the silica template
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