High Side Research Articles

Design and realization of a 200 A low-cost high-side switch for automotive applications

The realization of a high side power switch for driving a motor with a load current of 200 A in a hostile environment is presented. For such high currents currently electromechanical devices are used which have reliability and wear problems when working in environments with high temperature and humidity. The proposed solution was developed by connecting in parallel five commercial switches mounted on an FR4 support. An accurate thermal design, aided by finite element analysis, made it possible to avoid the use of an external heat sink, thus minimizing the weight and cost of the assembled circuit. Experimental tests under actual operating conditions have demonstrated the reliability of the proposed solution.

A comparison of the influence of plasmoid-drift mechanisms on plasma fuelling by cryogenic pellets in ITER and Wendelstein 7-X

Pellet injection is the most promising technique to achieve efficient plasma core fuelling, key for attaining stationary scenarios in large magnetic confinement fusion devices. In this paper, the injection of pellets with different volumes and speeds into standard plasma scenarios in ITER (tokamak) and Wendelstein 7-X (stellarator) is studied by modeling the pellet ablation and particle deposition, focusing on the evaluation of the expected differences in pellet plasmoid drifts in tokamaks and stellarators. Since the efficiency of the damping-drift mechanisms is predicted to depend on the magnetic configuration, device-specific characteristics are expected for the temporal evolution of the plasmoid drift acceleration. For instance, plasmoid-internal Pfirsch–Schlüter currents dominate the drift damping process for stellarators, while plasmoid-external currents are more relevant for tokamaks. Also, relatively larger drifts are in principle expected for W7-X due to higher field gradients in relation to machine dimensions. However, shorter plasmoid-internal charge reconnection lengths result in the drift damping due to internal Pfirsch–Schlüter currents being more effective than in a tokamak. Therefore, the average relative drift displacement during the whole plasmoid homogenization may a priori be comparable in both magnetic configurations. Moreover, High Field Side (HFS) injection is expected to be highly advantageous to maximize pellet particle deposition in ITER, whereas it may only be beneficial in medium to high β environments in W7-X. Finally, there may be means for the optimization of pellet injection configurations in both ITER and W7-X for the considered plasma scenarios despite the sizeable differences in the relative importance of the mechanisms of plasmoid drift acceleration and deceleration in play.

DESIGN AND ANALYSIS OF BIDIRECTIONAL BUCK-BOOST CONVERTER FOR GRID TO PHEVAND PHEV TO HOME

Nowadays, the use of Electric Vehicles (EV) is rapidly increasing. The batteries of the EV are charged when its demand is low, and the energy would then be stored to act as a kind of reserve that could be used when necessary. A new design of “bidirectional DC-DC buck boost converter” is suggested for transferring electrical power between the grid and an electric vehicle, as well as between an electric vehicle and the residence. While using grid energy to charge the car battery, the Grid to Vehicle (G2V) mode utilizes a buck mode DC-DC converter operation. The Vehicle to Home (V2H) function uses the battery's stored energy to power dwellings off the grid when the DC-DC converter is running in boost mode. The battery's Status of Charge is determined using an enhanced Kalman filter. Proportional-integral controllers are used in bidirectional buck boost converters to maintain a consistent voltage on both the high voltage and low voltage sides. Phase angle control is used for G2V and V2H operations on the H-Bridge inverter that the DC-DC converter is coupled with. The proposed circuit is simulated in MATLAB, and the results are reviewed.

First analysis of in-situ melting on TZM tiles at high field side of the first wall in EAST

First analysis of in-situ melting on TZM tiles at high field side of the first wall in EAST

Biofeedback Has Therapeutic Effects on Asthma, Although Additional Research Is Needed to Document Specificity

Asthma is a common disorder leading to significant disability and healthcare cost throughout the world. Although medical treatment is usually highly effective in controlling it, asthma medicines often have high costs and attendant side effects. Biofeedback is an inexpensive noninvasive alternative with minimal side effects. This paper reviews evidence for two validated biofeedback treatments for treating asthma, heart rate variability biofeedback (HRVB), and muscle relaxation with surface electromyographic biofeedback. In multiple studies, although most of them are of modest size, both methods have clinically meaningful results, often allowing decreases in the use of steroid medication. Further research is needed to prove which specific components of HRVB are responsible for clinical effects, and to determine asthma populations that can best benefit from these methods. Despite demonstrated effectiveness, few insurance schemes reimburse for biofeedback, and national guidelines consider it only as worthy of further investigation. Funding for the requisite large-scale clinical trials remains lacking, creating a limbo-like status quo for these useful methods.

Single-Phase H-Bridge Rectifier Fed High-Speed SRM System Based on Integrated Power Control

Traditionally, an uncontrollable diode bridge rectifier (DBR) is employed to supply the constant DC voltage for the asymmetric half-bridge (ASHB) converter fed switched reluctance motors (SRMs), which brings about inferior AC side power quality. In this article, a high-speed SRM drive system based on integrated power control scheme is proposed, which not only realizes the regulation of SRM but improves the AC side power quality. For the topology, a single-phase H-bridge rectifier and ASHB converter are connected in a cascade arrangement to form an AC-DC-DC converter to drive the SRM. For the control, the proposed integrated power control scheme governs the rectifier and SRM as one control unit in which stable motor speed and high AC side power factor are realized via regulating the input real and reactive power, respectively. Moreover, the proposed system has bi-directional power flow capability, which means the power can flow out of and into the AC side. Experiments are carried out to investigate the steady-state and dynamic performances of the proposed driving system. The experimental data and performance comparison confirm its effectiveness.

Short-chain fatty acid-releasing nano-prodrugs for attenuating growth and metastasis of melanoma.

Low-molecular-weight (LMW) short-chain fatty acids (SCFAs), such as propionic and butyric acids, have been reported to possess anti-neoplastic effects; however, rapid renal clearance and high dose-based side effects limit their clinical translation. Hence, in this study, we have designed a new self-assembling nano-prodrugs that can effectively supply SCFAs: endogenous enzyme-metabolizable block copolymer poly(ethylene glycol)block-poly(vinyl ester) possessing several units of SCFAs conjugated as side chains via ester linkages. These amphiphilic polymers spontaneously self-assemble into nanostructures under aqueous conditions to form orally administrable nano-prodrugs (butyric acid: NanoBA and propionic acid: NanoPA). Herein, we show the therapeutic efficacy of SCFA nanoparticles (NanoSCFA) in a mouse model of metastasis (melanoma). Ad libitum intake of our NanoSCFA markedly demonstrated a decrease in the metastatic tumor nodules in the lungs compared with the effect observed after LMW SCFA administration with no discernible toxicity to the GI tract. In contrast, LMW SCFAs, even at a lower concentration than that of the NanoSCFA, facilitated villus atrophy. Taken together, our work suggests that the use of NanoSCFA as a therapeutic intervention for metastatic cancer is preferable over typical LMW SCFAs. STATEMENT OF SIGNIFICANCE: Low-molecular-weight (LMW) short-chain fatty acids (SCFAs) have shown versatile therapeutic effects on various diseases, including anti-tumorigenesis effects. However, their clinical translation is limited due to their poor pharmacokinetic profile and adverse effects. To overcome these limitations, we have developed new amphiphilic block copolymer-based SCFA-prodrugs, which self-assemble into nanoparticles in aqueous media (NanoSCFA). SCFAs are covalently conjugated to the hydrophobic polymer segment via ester linkage, which can be enzymatically metabolized after oral administration. In the present study, we confirmed that ad libitum intake of NanoSCFAs retarded the growth and metastatic potential of B16-F10 tumors compared to the LMW SCFAs with negligible discernible toxicity, reflecting NanoSCFA as a preferable therapeutic intervention to LMW SCFA counterparts.

The Relationship between Intestinal Flora and Sleep Disorders and Research Progress

Insomnia is one of the most common sleep disorders, which is closely related to mood and stress. Long-term insomnia can not only lead to fatigue, poor concentration and other problems, but more serious cases can lead to memory loss, mood disorders and even neurodegenerative diseases. The current chemotherapeutics have many defects, such as high side effects and insufficient efficacy, so it is urgent to develop new prevention and treatment strategies. In recent years, with the deepening understanding of the ‘microbiome-gut-brain’ axis in the scientific community, gut microbes have been shown to regulate sleep function by communicating with the brain through several mechanisms: regulating the serotonin system; Regulating the blood-brain barrier; Produce functional metabolites. Breakthroughs have been made in theory to regulate the host’s biological rhythm and improve the nervous system problems caused by sleep disorders. It has great practical significance. Starting from the pathological mechanism of insomnia (including neurotransmitter system disorders and disorder of the Hypothalamic-Pituitary Aadrenal Axis (HPA) system), this paper will explain the pathogenesis of intestinal flora in sleep disorders and the interaction and internal relationship between the two.

Effect of Median Application on Section Road Performance Based on Degree of Saturation and Speed at Road of Small Town in Lombok, Indonesia

Road traffic safety is a global concern for people and governments. This is because unsafe roads are among the major causes of traffic accidents, which can result in severe injury and even death. One of the significant ways to minimize traffic movement problems, especially those related to road safety and comfort, is to build a median. Therefore, this research was carried out to determine the performance of roads with and without the median application using the TGH Ibrahim Kholidi road segment, West Lombok Regency, Indonesia. The road section is located in a small town with characteristics such as pedestrians, light and heavy vehicles, as well as traders who use the available inadequate parking spaces, thereby causing high side friction. A quantitative research with data collected by surveying the road section was subsequently employed to determine the traffic volume, speed, side friction, road geometric, and population from the 1997 Indonesian Road Capacity Manual (MKJI-1997) guidelines. The collected data were analyzed using the Separation Planning Procedure. The results showed that using the median increased performance by 45.7% compared to no median. This is in addition to a decrease in the Degree of saturation (DS) from 0.7 to 0.38 or from LOS C to B. Furthermore, the average speed increased from 32.4 km/h (without median) to 33.92 km/h (with median).

Fucoidan-loaded, neutrophil membrane-coated nanoparticles facilitate MRSA-accompanied wound healing

Treatment of methicillin-resistant Staphylococcus aureus (MRSA)-infected wounds remains an important clinical challenge. Current treatments using vancomycin usually result in high side effects with low treatment efficacy because of strong drug toxicity and weak targeting specificity. It is emergently needed to develop a novel antimicrobial agent and target drug delivery system. Herein, we developed anti-infection nanoparticles (LMM NPs) with autonomous targeting ability, loading low-molecular-weight fucoidan (LMWF) and coated by neutrophil membranes, and used for the therapy of MRSA-infected wounds. The LMWF molecules possess similar anti-MRSA effects as vancomycin but lower nephrotoxicity. Nanoparticles coated with the neutrophil membrane can escape immune recognition due to the retained cell membrane components and accumulate in the infection site. Furthermore, the MRSA-infected wound model confirms that the LMM NPs accumulate efficiently in MRSA-infected tissues and have good biocompatibility and excellent antibacterial ability in MRSA-infected wounds, which promote MRSA-accompanied wound healing. These novel infection-targeted LMWF-loaded NPs could be applied as a useful strategy for the targeted treatment of infection therapy. This will provide a meaningful reference to extend clinical treatment in MRSA infection of deep tissues.

Plant-derived natural products and combination therapy in liver cancer.

Liver cancer is one of the malignant cancers globally and seriously endangers human health because of its high morbidity and mortality. Plant-derived natural products have been evaluated as potential anticancer drugs due to low side effects and high anti-tumor efficacy. However, plant-derived natural products also have defects of poor solubility and cumbersome extraction process. In recent years, a growing numbers of plant derived natural products have been used in combination therapy of liver cancer with conventional chemotherapeutic agents, which has improved clinical efficacy through multiple mechanisms, including inhibition of tumor growth, induction of apoptosis, suppression of angiogenesis, enhancement of immunity, reversal of multiple drug resistance and reduction of side effects. The therapeutic effects and mechanisms of plant-derived natural products and combination therapy on liver cancer are reviewed to provide references for developing anti-liver-cancer strategies with high efficacy and low side effects.

The versatile fueling systems of WEST

New fueling systems have been designed for WEST, a full tungsten wall tokamak with divertor configuration. They consist of standard gas injection, supersonic molecular beam injection and pellets injection systems, each being able to fuel continuously the plasma discharge up to a duration of 1000s. A massive gas injection system is also implemented to mitigate the impact of disruptions and runaway electrons. The standard gas system consists of 4 independent lines allowing the injection of up to 4 different gas species during a plasma discharge through 11 injections areas, 4 of them being located in the divertors and in the private flux region. The pellet injection system is able to inject up to 10 pellets per second through 4 tracks: one on the low field side, and the other 3 on the high field side. The supersonic molecular beam injection system consists of 3 injectors located close to the midplane, two on the high field side and one on the low field side. On trigger, the massive gas injection system can deliver in a single puff up 800 Pa.m3 of noble gas in order to stop the plasma discharge. All the fueling systems have been characterized and can be used routinely on plasma.

Experimental investigation of toroidal eddy current in the in-vessel components during plasma disruption in the KSTAR tokamak

The total toroidal eddy current in the in-vessel components evaluated from the difference between a discrete and continuous Rogowski coil measurements in the KSTAR tokamak was previously reported in [1]. For the eddy currents evaluated from 305 disrupted plasma discharges, it is found that while the peaked value of the eddy current linearly correlates with the value of plasma current Ip, it weakly depends upon the current quench rate. In addition, the eddy currents in the inner and outer parts of the in-vessel components during plasma disruption are assessed from two different Rogowski coil measurements, and the eddy current in the inner part decays faster than one in the outer part. The eddy current in the outer part is validated by comparing it with the eddy current directly measured at the gap resistors in the passive stabilizer. While the eddy currents in the two parts are comparable for plasma disruption at the high field side, the eddy current in the outer part is quite large for the disruption at the low field side. The magnitude of the eddy current at the same side where the disruption occurs is higher than that at the other side. The eddy current in the counter-Ip direction is always detected during the vertical displacement event and its maximum value linearly correlates with the vertical growth rate.

Wind-Induced Responses and Wind Loads on a Super High-Rise Building with Various Cross-Sections and High Side Ratio—A Case Study

With the development of construction technology and material, more and more super high-rise buildings will be constructed in the future. In a specific metropolitan area, super high-rise building with various cross-section and high side ratio have to been designed and constructed due to the size limitation of construction site. This kind of building is also very prone to wind excitations. In this research, wind tunnel tests for a practical case of this kind of building with surrounding buildings were carried out in atmospheric boundary wind tunnel. Equivalent static wind loads (ESWLs), wind-induced responses and wind load distribution on the building were analyzed. In particular, the base overturning moment along the axis with weak lateral stiffness were investigated for bearing capacity limit state design of the building. The results demonstrate that the maximum value of wind-induced base overturning moments and acceleration responses appears at 60° or 330° wind directions instead of the orthogonal wind direction, and the aerodynamic interference of surrounding buildings affects the wind pressure distribution on facades of the building. These results and conclusion may be helpful to wind-resistant design of super high-rise buildings with high side ratio.

STUDY OF A SOLAR ENERGY KALINA CYCLE APPLIED IN BOM JESUS DA LAPA - BAHIA

Modern population’s needs increased demands for electricity in such a way that new energy sources were explored, in search of lower environment impacts and fossil fuels dependency. Renewable energy sources for electricity production, such as solar and wind energy, have significantly attracted attention and places as the west region of Bahia state has a good potential for its application. This location is characterized by high solar irradiance of 2136 kWh/m² a year, already having 4 photovoltaic power plants in operation and 2 more in project phases. Another possible application is the solar thermal energy and Kalina Cycle presents as a good possibility for employing it, since the non-azeotropic mixture of ammonia-water as working fluid allows low temperature heat sources utilization. Based on that, this research proposed the study of a Kalina power cycle, with steady state conditions, using thermal solar energy as low temperature heat source and applied to the solar irradiance of Bom Jesus da Lapa – BA. The thermodynamic cycle was developed and simulated with Engineering Equation Solver (EES®), thermal efficiency was analyzed by varying parameters such as: heat source temperature from 90 °C to 120 °C, high pressure line from 10 to 35 bar and ammonia mass fraction from 0.35 to 0.95. The final cycle presented a superheater before the turbine and a regenerator with poor ammonia-water mixture from the separator (as hot side) and ammonia-water mixture before entering the boiler (as cold side). Results indicated maximum efficiency of ~7.4%, with high pressure side of 35 bar, heat source temperature of 120 °C, superheater heat source temperature of 200 °C and ammonia mass fraction of 0.64 kg/kg.

Analysis of fluid-structure interaction in a directional permeability membrane in pressure-driven flow

Finite volume and finite element analysis of fluid-structure interaction is performed to understand the behavior of a directional permeability membrane in pressure-driven flow. The membrane is comprised of two flexible porous sheets separated by a spacer. The porous sheets each have a different thickness with pores that are offset from each other. The design allows flow when the thicker sheet is on the high pressure side, but prevents flow if the pressure gradient is reversed. Flow through the membrane is studied for a pressure range of 0.01–0.1 m H2O in forward flow to understand the complex fluid motion and dependence of membrane deformation on sheet thickness, downstream pore diameter, and initial gap between the sheets. In forward flow, maximum mass flow rate of 0.2 g s−1 (or flow rate of 12.024 ml min−1) can be obtained at 0.1 m H2O pressure head. Reverse flow conditions are modeled to study the effect of design parameters on the required closing pressure, indicating that as little as 0.0325 m H2O of pressure head is required for closing.

High Interest in Long-acting Injectable Pre-exposure Prophylaxis (LAI-PrEP) for HIV Prevention Among Men Who Have Sex With Men (MSM): Result From A Nationwide Survey in Malaysia.

The recent approval of long-acting injectable cabotegravir (CAB-LA) as PrEP for HIV prevention could be an attractive alternative for MSM, particularly among those who face barriers to adherence using the oral pill. This study reports on the awareness of long-acting injectable PrEP (LAI-PrEP) and factors associated with interest in LAI-PrEP use among a nationwide sample of MSM in Malaysia. An online cross-sectional survey was conducted between August and September 2021 to explore perspectives on PrEP modalities among Malaysian MSM (N = 870). Convenience sampling was used to recruit participants using ads on two platforms hornet and facebook. While only 9.1% of the study participants were aware of LAI-PrEP, the majority had heard of oral PrEP (80.9%). After giving a description of it, a large majority (86.6%) expressed interest in using it if made accessible. Those who had a prior history of HIV testing (aOR = 1.9; 95% CI = 1.2-3.2) were more likely to use LAI-PrEP. Interestingly, despite the concerns related to potential high cost (aOR = 3.4; 95% CI = 2.1-5.5) and long-term side effects (aOR = 1.9; 95% CI = 1.2-3.1), the majority of the participants were interested in using LAI-PrEP. Those who were afraid of (or disliked) syringes were less interested in using it (aOR = 0.2; 95% CI; 0.1-0.4). In the recent context that LAI-PrEP was shown to be safe and effective at preventing HIV, our results indicate its potential relevance as an additional PrEP option that could accelerate the uptake and scale-up of PrEP. However, it is crucial to conduct future research urgently to improve the understanding of strategies that could enhance the accessibility, acceptability, and affordability of LAI-PrEP for MSM in low- and middle-income countries, including Malaysia.

Regulatory Effects of Thai Rice By-Product Extracts from Oryza sativa L. cv. Bue Bang 3 CMU and Bue Bang 4 CMU on Melanin Production, Nitric Oxide Secretion, and Steroid 5α-Reductase Inhibition.

Alopecia and gray hair are common hair abnormalities affecting physical appearance and causing psychological problems. Chemical treatments partially restore hair disorders but have distressing side effects. Bioactive plant compounds constitute promising sources of potential medicinal substances instead of chemical agents, producing high side effects. In this study, we focused on the waste of local rice cultivars: Bue Bang 3 CMU (BB3CMU) and Bue Bang 4 CMU (BB4CMU) from the north of Thailand. The rice bran oil (RBO), defatted rice bran extract (DFRB), and rice husk (H) were determined for in vitro hair revitalization in melanin production, nitric oxide (NO) secretion, and steroid 5α-reductase inhibition. The results indicated that BB4CMU-RBO with high contents of iron, zinc, and free fatty acids showed a comparable induction of melanin production on melanocytes (130.18 ± 9.13% of control) to the standard drug theophylline with no significant difference (p > 0.05). This promising melanin induction could be related to activating the NO secretion pathway, with the NO secretion level at 1.43 ± 0.05 µM. In addition, BB4CMU-RBO illustrated a significant inhibitory effect on both steroid 5α-reductase genes (SRD5A) type 1 and type 2, which relates to its primary source of tocopherols. Hence, rice bran oil from the Thai rice variety BB4CMU could be applied as a promising hair revitalizing candidate, from natural resources, to help promote hair growth and re-pigmentation effects.

Influence of Eu3+ on the structural, optical and electrical properties of PEO–PVA: dual bandgap materials for optoelectronic applications

Solid-polymer electrolytes (SPE) based on rare-earth doping is a growing approach for the development of various optoelectronic and ion-conducting devices. Eu3+/PEO–PVA SPE was prepared by solution casting. The impacts of Eu3+ content on the microstructure, chemical composition, and complexation with the functional groups of the blend as well as on the film morphology were evaluated by X-ray diffraction, FT-IR spectroscopy, and FE-SEM microscopy. It was revealed that the film's crystallinity and optical transmittance can be tailored by Eu3+ content. Tauc's method illustrated that the films exhibit dual band gaps on both the low energy side (2.0–2.8 eV) and the high energy side (4.0–4.38 eV). In addition, the refractive index and optical conductivity of SPE were greatly enhanced with increasing Eu3+ content. The current–voltage characteristic curves were recorded at an applied voltage range of 0–10 V, and temperature range of 30–100 °C. The materials exhibited non-Ohmic behavior. The DC conductivity ({sigma }_{mathrm{dc}}) values of the pure and 6 wt% Eu3+-doped blend were in the range of 1.16 × 10–6–2.05 × 10–6 S/cm and 1.73 × 10–6–3.36 × 10–6 S/cm, respectively. The relations between the current density and the electric field revealed that the Schottky emission is the most suitable conduction mechanism. The results indicate that Eu3+/PEO–PVA SPE is suitable for some optoelectronic applications and ion-conducting devices.

A DAB-Based DC Transformer for Multiterminal HVdc Dynamic Simulation Platform With Short Circuit Tolerance

The dc transformer (DCT) can be used to achieve a direct connection between various dc bus voltages. A multiwinding dual active bridge (DAB) structure is proposed to be used in that occasion for a dynamic simulation platform. For high voltage side, automatic voltage balance and power-sharing balance can be achieved automatically without mandatory power sharing control. To deal with wide voltage conversion gain application, a multimode modulation with peak current value optimization is proposed. It has the tolerance for the short circuit operation under dc fault. The power transmission can be suppressed rather low during the fault. A 1 kV/1.6 kV 10 kW DCT has been fabricated and applied in a dynamic simulation platform. The bidirectional power flow capability together with the short circuit fault tolerance has been verified through the test.