Dual Supply Research Articles

Mathematical model of an asynchronous machine in real coordinates of state

A mathematical description of an asynchronous machine with unreduced parameters in the space of real phase coordinates is given. When studying an asynchronous motor in a dual power supply system with controlled converters in rotor and stator circuits, there is a need for an AM model without parameters, in which the processes in the stator and rotor circuits will correspond to reality in magnitude. In addition, such a model is necessary when analyzing the energy parameters of the whole electric drive controlled by the rotor. To observe real processes in the stator and rotor, the model should be designed in separate spatial coordinate systems. In reference books for AM with a wound rotor (WR), as a rule, the real parameters (resistances, currents and voltages) of the stator and rotor and the voltage reduction coefficient ( ke ) are given. Bringing currents and resistances (inductances) is carried out by coefficients ki=ke and kr=ke2 respectively. Let's consider the description of the machine without reduction of parameters. For the convenience of further consideration, let's introduce the general value of the mutual inductance.
 We obtain an equation for the electromagnetic moment in real coordinates. Let's design a model in the MATLAB dynamic modeling environment using vector-matrix representation. Matrix algebraic operations with vector variables are implemented by Matlab Fn blocks, which are the calls to userdefined functions described in the form of M-files. The content of Matlab Fn functions is considered. On the model, the processes of starting of an AM with a phase rotor of AK-52-6 type were. Shows the graphs of start-up transients. The processes in the obtained model coincided with the results of modeling of this engine in the model with the coordinates reduced to the rotor. Thus, the energy processes described by this model correspond to the processes to the model with the given parameters, and the processes of currents and flux linkages changing of the stator and rotor are real.
 The model designed in the MATLAB/Simulink dynamic modeling environment can be used to study double-powered asynchronous electric drives.

Hepatic Diseases in Canine and Feline: A Review

Dogs and cats are belonging to canine and feline family respectively. The liver is the largest gland in the body and is located in the cranial abdomen between 3rd and 4th ribs in dogs and cats. This review is mainly focused on: to understand the anatomy and physiology of liver, the liver diseases pathophysiology, to diagnose the liver diseases, managemental and ameliorative methods of liver diseases. The dual blood supply to the liver is hepatic artery and portal vein. The function of liver includes the regulation of digestion and metabolism, the synthesis of hormones and proteins, immune response and filtering of toxins from the blood stream. Any problem that affects the liver is liver disease. Inflammation of liver is hepatitis. Hepatitis caused by infectious, non-infectious, auto-immune and reactive. It can be acute and chronic. The most encountered liver diseases in dogs and cats are hepticlipidosis, cholangiohepatitis, portosystemicshunt, cholelithiasis, choledocholithiasis, cholecystitis, pneumobilia and hepatic neoplsia. The clinical symptoms of liver diseases include jaundice, hepatic encephalopathy, gastro intestinal disorders and nonspecific signs include polyuria/polydipisia. The liver disease diagnosed based on history, liver function tests, medical imaging. The latest imaging procedures are endoscopic retrograde cholagio pancreatography (ERCP) and computed tomography (CT). For confirmatory diagnosis liver biopsy and histopathological interpretation is required. Therefore, based on diagnosis appropriate treatment should be selected: bile stasis is treated urodeoxycholic acid (URDA), fluid therapy include sugar and salt solution for replacement fluid loss, gastrointestinal protectors include ranitidine, cimitidine and lactulose, albumin to treat hypoalbuminimia, antioxidant for scavenging free radicals include vitamin E, Selenium, S-adenosyl-L-methionine (SAMe), diuretic fursimid for treatment of ascites and supplementation low protein diets. This laparoscopic technique for removal of gallstones and endoscopic retrograde cholagiopancreatography (ERCP) to treat gall stones on bile ducts and to widen the slipped ducts and liver transplantation for cirrhotic dogs and cats. Early accurate diagnosis and managing any predisposing factors that affects the health of dogs and cats are important for controlling the liver diseases.

Fault Location of Distribution Internet of Things in Electricity Using Ant Colony Optimization Algorithm

To improve the accuracy of fault location for distribution Internet of Things in electricity based on feeder terminal units (FTUs), the ant colony optimization algorithm is used. The basic principle of fault location for distribution Internet of Things in electricity and the ant colony optimization algorithm is introduced, and the programs of fault location for distribution Internet of Things in electricity based on the improved unified matrix algorithm and the ant colony optimization algorithm are written. They are used to locate fault for distribution network with dual power supply. The results reveal that if all FTUs contain correct information, the unified matrix algorithm and the ant colony optimization algorithm can accurately locate fault. If some FTUs contain false information, the improved unified matrix algorithm may get the wrong results. However, the ant colony optimization algorithm can obtain accurate result when only small quantities of FTU information are false. The computation time of the ant colony optimization algorithm is much longer than that of the improved unified matrix algorithm. The ant colony optimization algorithm is more suitable for the case in which FTU information is easily false.

Safe stroke of vacuum breaking process in DC circuit breaker commutated by intermediate frequency current

The safe stroke between contacts of vacuum switch is the key parameter that can withstand transient recovery voltage (TRV) after arc extinction. In order to determine the minimum safe stroke during direct current (DC) interruption, this paper starts with the characteristic analysis of the commutation process. After breaking current zero crossing, contact gap is used to correlate the dielectric recovery level with TRV. In terms of theoretical description, based on the sheath development analysis of continuous transition model (CTM), different commutation moments and frequency have a perceptible effect on the TRV and dielectric recovery process. The breaking test of DC synthesis circuit with dual power supply is used to further verify the dielectric recovery level of vacuum gap, and the minimum safe stroke corresponding to reliable interruption. Simulation and experimental results show that safe stroke increases with the higher breaking current, TRV and its change rate during the DC breaking process, the corresponding commutation moment should be delayed. Finally, the influence of arc appearance on the safe stroke is discussed by analyzing the arc image of the draw-arc process. The safe stroke is helpful to determine the time setting for commutation moment and reliable breaking process of DC vacuum circuit breaker.

Operational Amplifier Design Employing DTMOS Technique with Dual Supply Voltages

An operational amplifier (OPAMP) for portable devices with dual supply voltage is presented in this work. The design is realized with a 600[Formula: see text]mV supply for the core design and a 1.8[Formula: see text]V supply for the biasing circuit to improve input common mode range (ICMR), gain, and common mode rejection ratio (CMRR). The designed amplifier is implemented with dynamic threshold voltage MOSFET (DTMOS) transistors to decrease power consumption and increase the performance of the design. The power consumption of the core design is obtained as 2[Formula: see text][Formula: see text]W while the biasing circuitry consumes 7.38[Formula: see text][Formula: see text]W. The application of different supply voltages has greatly increased the gain of the circuit, where the circuit exhibits 100.2[Formula: see text]dB DC gain and 3.41[Formula: see text]MHz gain bandwidth product (GBW). CMRR of the designed circuit is 84.22[Formula: see text]dB. The simulations are performed in Cadence environment with 0.18[Formula: see text][Formula: see text]m CMOS technology.

Dual and Multi-channel closed-loop supply chains: A state of the art review

Dual and Multi-channel closed-loop supply chains: A state of the art review

The nano-scanning electrical mobility spectrometer (nSEMS) and its application to size distribution measurements of 1.5–25 nm particles

Abstract. Particle size measurement in the low nanometer regime is of great importance to the study of cloud condensation nuclei formation and to better understand aerosol–cloud interactions. Here we present the design, modeling, and experimental characterization of the nano-scanning electrical mobility spectrometer (nSEMS), a recently developed instrument that probes particle physical properties in the 1.5–25 nm range. The nSEMS consists of a novel differential mobility analyzer and a two-stage condensation particle counter (CPC). The mobility analyzer, a radial opposed-migration ion and aerosol classifier (ROMIAC), can classify nanometer-sized particles with minimal degradation of its resolution and diffusional losses. The ROMIAC operates on a dual high-voltage supply with fast polarity-switching capability to minimize sensitivity to variations in the chemical nature of the ions used to charge the aerosol. Particles transmitted through the mobility analyzer are measured using a two-stage CPC. They are first activated in a fast-mixing diethylene glycol (DEG) stage before being counted by a second detection stage, an ADI MAGIC™ water-based CPC. The transfer function of the integrated instrument is derived from both finite-element modeling and experimental characterization. The nSEMS performance has been evaluated during measurement of transient nucleation and growth events in the CLOUD atmospheric chamber at CERN. We show that the nSEMS can provide high-time- and size-resolution measurement of nanoparticles and can capture the critical aerosol dynamics of newly formed atmospheric particles. Using a soft x-ray bipolar ion source in a compact housing designed to optimize both nanoparticle charging and transmission efficiency as a charge conditioner, the nSEMS has enabled measurement of the contributions of both neutral and ion-mediated nucleation to new particle formation.

Development of a 5.8 MW dual output high voltage power supply with pulse step modulator module for KSTAR Helicon current drive system

In this study, a 5.8 MW high voltage power supply was developed for two 1.2 MW klystrons to operate the upgraded KSTAR helicon current drive system. The developed power supply was configured to connect 180 pulse step modulator (PSM) modules using semiconductor switches connected in series to produce an output with a rating of −92 kV and 64 A for 300 s. To operate the klystron individually, the output of the cathode power supply (CPS) is divided into two high voltage switches (HVSs). The HVS not only operates as an individual switching, but also cuts off the energy from being transferred to the load within 5 μs in case of an arc or short circuit. At this time, the energy should be 5 J or less. The individual PSM of the power supply is controlled by optic shifting distributor controller, and the overall control and protection are controlled by the CPS controller. Currently, this power supply is installed at KSTAR, and has been tested up to the maximum voltage of −92 kV for performance verification. In addition, the arc energy blocking performance was verified through the wire burning test of HVS. Furthermore, an actual load test was conducted on one klystron installed for operation; an RF test was conducted up to −70 kV, and the maximum output was measured up to 620 kW

Modeling nonalcoholic fatty liver disease on a liver lobule chip with dual blood supply

Nonalcoholic fatty liver disease (NAFLD) has emerged as a public health concern. To date, the mechanism of NAFLD progression remains unclear, and pharmacological treatment options are scarce. Traditional animal NAFLD models are limited in helping address these problems due to interspecies differences. Liver chips are promising for modeling NAFLD. However, pre-existing liver chips cannot reproduce complex physicochemical microenvironments of the liver effectively; thus, NAFLD modeling based on these chips is incomplete. Herein, we develop a biomimetic liver lobule chip (LC) and then establish a more accurate on-chip NAFLD model. The self-developed LC achieves dual blood supply through the designed hepatic portal vein and hepatic artery and the microtissue cultured on the LC forms multiple structures similar to in vivo liver. Based on the LC, NAFLD is modeled. Steatosis is successfully induced and more importantly, changing lipid zonation in a liver lobule with the progression of NAFLD is demonstrated for the first time on a microfluidic chip. In addition, the application of the induced NAFLD model has been preliminarily demonstrated in the prevention and reversibility of promising drugs. This study provides a promising platform to understand NAFLD progression and identify drugs for treating NAFLD. Statement of significanceLiver chips are promising for modeling nonalcoholic fatty liver disease. However, on-chip replicating liver physicochemical microenvironments is still a challenge. Herein, we developed a liver lobule chip with dual blood supply, achieving self-organized liver microtissue that is similar to in vivo tissue. Based on the chip, we successfully modeled NAFLD under physiologically differentiated nutrient supplies. For the first time, the changing lipid zonation in a single liver lobule with the early-stage progression of NAFLD was demonstrated on a liver chip. This study provides a promising platform for modeling liver-related diseases.

Transarterial Radioembolization Agents: a Review of the Radionuclide Agents and the Carriers.

Liver tumors, both primary and secondary to metastatic disease, remain a major challenge, with an increasing incidence. In this context, taking advantage of the dual blood supply of the liver, and the fact that liver tumors derive majority of their blood supply from the hepatic artery, intraarterial therapies are gaining popularity. Intraarterial liver-directed therapy (IALDT) is the option when the surgery is not feasible due to the number of metastases or for other reasons. Transarterial radioembolization (TARE) is a specific type of IALDT, where a carrier particle/microsphere is labeled with a radioactive substance and then is injected into hepatic artery for therapeutic purposes. As this field is rapidly evolving, with multiple agents being investigated and being introduced into clinical practice, it is hard for the practitioners and researchers to encompass all the available information concisely. This article aims to present a comprehensive review of the prominent TARE technologies.

X-band monolithic three-stage LNA with GaAs E-mode PHEMT

An LNA for 8∼12 GHz is proposed in this paper. The amplifier uses a GaAs process with cost-effective, E-mode HEMTs with gate widths of 0.25 µm and 0.45 µm. The three stages of the LNA are powered by dual power supplies, with a drain operating voltage of +3V and a gate operating voltage of +0.7V. The simulation results of the schematic diagram show that the noise factor of the low-noise amplifier is less than 2.5dB in the frequency range of 8-12GHz, the in-band gain is greater than 30dB, the gain flatness is ±1.5dB, the 1dB compression point is 7dbm, the VSWRs are less than -10dB, and the LNA is absolutely stable in the X-band.

A dual supply chain revenue sharing contract considering online reviews and rebate

A dual supply chain revenue sharing contract considering online reviews and rebate

Hepatic Arterial Infusion Chemotherapy for Unresectable Intrahepatic Cholangiocarcinoma, a Comprehensive Review.

Cholangiocarcinoma (CCA) is the second most common primitive liver cancer. Despite recent advances in the surgical management, the prognosis remains poor, with a 5-year survival rate of less than 5%. Intrahepatic CCA (iCCA) has a median survival between 18 and 30 months, but if deemed unresectable it decreases to 6 months. Most patients have a liver-confined disease that is considered unresectable because of its localization, with infiltration of vascular structures or multifocality. The peculiar dual blood supply allows the delivery of high doses of chemotherapy via a surgically implanted subcutaneous pump, through the predominant arterial tumor vascularization, achieving much higher and more selective tumor drug levels than systemic administration. The results of the latest studies suggest that adequate and early treatment with the combination approach of hepatic arterial infusion (HAI) and systemic (SYS) chemotherapy is associated with improved progression-free and overall survival than SYS or HAI alone for the treatment of unresectable iCCA. Current recommendations are limited by a lack of prospective trials. Individualization of chemotherapy and regimens based on selective targets in mutant iCCA are a focus for future research. In this paper we present a comprehensive review of the studies published to date and ongoing trials.

Hippocampal vascularization patterns exert local and distant effects on brain structure but not vascular pathology in old age.

The hippocampus within the medial temporal lobe is highly vulnerable to age-related pathology such as vascular disease. We examined hippocampal vascularization patterns by harnessing the ultra-high resolution of 7 Tesla magnetic resonance angiography. Dual-supply hemispheres with a contribution of the anterior choroidal artery to hippocampal blood supply were distinguished from single-supply ones with a sole dependence on the posterior cerebral artery. A recent study indicated that a dual vascular supply is related to preserved cognition and structural hippocampal integrity in old age and vascular disease. Here, we examined the regional specificity of these structural benefits at the level of medial temporal lobe sub-regions and hemispheres. In a cross-sectional study with an older cohort of 17 patients with cerebral small vessel disease (70.7 9.0 years, 35.5% female) and 27 controls (71.1 8.2 years, 44.4% female), we demonstrate that differences in grey matter volumes related to the hippocampal vascularization pattern were specifically observed in the anterior hippocampus and entorhinal cortex. These regions were especially bigger in dual-supply hemispheres, but also seemed to benefit from a contralateral dual supply. We further show that total grey matter volumes were greater in people with at least one dual-supply hemisphere, indicating that the hippocampal vascularization pattern has more far-reaching structural implications beyond the medial temporal lobe. A mediation analysis identified total grey matter as a mediator of differences in global cognition. However, our analyses on multiple neuroimaging markers for cerebral small vessel disease did not reveal any evidence that an augmented hippocampal vascularization conveys resistance nor resilience against vascular pathology. We propose that an augmented hippocampal vascularization might contribute to maintaining structural integrity in the brain and preserving cognition despite age-related degeneration. As such, the binary hippocampal vascularization pattern could have major implications for brain structure and function in ageing and dementia independent of vascular pathology, while presenting a simple framework with potential applicability to the clinical setting.

Acesso radial distal para prevenir a oclusão proximal da artéria radial: o que realmente se sabe?

Transradial access (TRA) offers important advantages over transfemoral approachs, including early patient ambulation, improved patient comfort, less vascular complications, lower health care costs, and reduced adverse cardiovascular events, including mortality. Nevertheless, complications of TRA still exist, and radial artery occlusion (RAO) occurred in up to 30% of cases, in a prospective vascular ultrasound study. Due to dual blood supply to the hand, RAO is usually asymptomatic and unnoticeable, although sometimes it may be associated with distal ischemia, paresthesia, pain at [...]

A novel memristor emulator design and universal biquad filter application using second generation high swing differential current conveyor transconductance amplifier in 130 nm CMOS process

Memristors have drawn a significant wide spread attention from the research community since past decade due to their high-speed operational potential in analog applications. However, it has been difficult to achieve the memristor behavior directly from solid state solution and state of the art. This work presents a novel emulator design to mimic the memristor behavior. A generic and simple emulator circuit for a voltage controlled memristor is presented using a differential difference current conveyor transconductance amplifier (DDCCTA), which is based on a versatile second-generation current conveyor methodology. A high-swing (up to ±600 mA at the output) and low power implementation design effort for DDCCTA is kept in 130 nm RF-CMOS process with dual power supply mode. The functional simulations have been performed in SPICE environment using Advanced Design System (Keysight Technology), which showed a good alignment to the memristor emulator’s I-V characteristic at 1 KHz and 10 KHz. Proposed DDCCTA then implements the memristor operation with compatible specifications. Finally, the memristor operation and potential has been verified by its application in high-speed active filter operations. A universal biquad section has been presented which employs the designed memristor emulator, with 30 mW of power dissipation with ±1.5 V supply.

Vascular mechanisms and manifestations of COVID-19

Vascular mechanisms and manifestations of COVID-19

Physicians' Dual Practice: A Theoretical Approach

The present study seeks to evaluate the theoretical approach towards physicians’ dual practice. This is done by investigating the various theoretical grounds that form the basis of physicians’ dual practice. The study presents theoretical findings by comparing them with practical primary data from experienced experts. An in-depth search of the top keywords related to dual practice was done in various databases. The study first identified all articles related to dual practice in various databases. In total, 59,838 articles identified after duplicates were removed were narrowed down to four hundred and thirty-eight (438) studies and considered relevant for review. The filtration process was carried out based on the recentness of the articles. A review of the articles was done to eliminate duplicates, a linguistic check was conducted, and a final sorting was carried out to arrive at fully accessible reviewed articles in the journal databases. Filtration was done to select fully accessible publications under the following keywords: Herzberg’s two-factor theory, contract theory, and supply of labour theory. Forty-one (41) fully accessible and peer-reviewed articles were used for analysis. The study underscores that dual practice can be theoretically modelled as a function of three theories (Herzberg’s two-factor theory, contract theory, and supply of labour theory). It is paramount, therefore, for studies to appreciate the theories in understanding the motivation behind the dual practice. Thus, the present study has proposed a hybrid integrated theory, the Integrated Theory of Labour, Supply and Motivation, in order to offset the weaknesses of the theories and build on their strengths.Implications for Central European audience: This study proposes the Integrated Theory of Labour, Supply and Motivation in order to help researchers and government institutions better address the concept of moonlighting in public institutions. The study concludes that future scholars and researchers in related fields could extrapolate the Integrated Theory of Labour, Supply and Motivation by conducting a factor analysis in order to validate the theory since it offers a platform to cover the drivers behind the dual practice in a comprehensive manner and also builds on the strengths of other theories explaining the dual practice. Theoretically, the study also validates the theories it uses and the extent of their applicability to this and similar studies. This is not through ruling out theories explaining dual practice but reinforcing them. The findings of this study may be useful in shaping policy in the area of managing contracts for physicians in dual practice and supply of labour economics in general.

Endovascular treatment of unique colonic arteriovenous malformation with dual supply from superior and inferior mesenteric arteries

Colonic arteriovenous malformations (AVMs) are well recognized in the literature and commonly manifest as colitis, abdominal pain, and rare cases have been reported of liver congestion. Dual-supply superior artery/ inferior mesenteric artery (SMA/IMA) colonic AVMs have never been reported and only one case of treating portal hypertension due to an AVM with an endovascular approach has been reported. We present a case of dual-supply SMA/IMA colonic AVM manifesting as hepatic venous congestion and demonstrate an endovascular approach to treatment. Level of evidence: Level 4, case series.

Cone-Beam Computed Tomography Fusion Technique for Vascular Assessment of Skull Base Meningiomas

Cone-beam computed tomography (CBCT) images for skull base tumors provide detailed vascular information and localization in regard to surrounding bony structures. We report use of the CBCT fusion technique for skull base meningiomas. Six patients with petroclival or petrotentorial meningiomas supplied by multiple arterial systems were preoperatively evaluated using CBCT fusion imaging. Fusion images were reconstructed from three-dimensional rotational angiography with contrast agent injections from the internal carotid artery (ICA) and external carotid artery in 4 cases, vertebral artery and external carotid artery in 1 case, and ICA and vertebral artery in 1 case. The feeding pedicles and tumor stains from 2 arterial systems were differentiated by separate colors. The courses and territories of the ICA dural feeders or ICA/vertebral artery pial feeders were easily distinguished from the external carotid artery dural feeders. Anastomoses between thin feeders from different arterial systems could be detected. Mixed stain (stain with both colors) was observed in some tumor compartments, suggesting dual supply from 2 arterial systems and the presence of peritumoral anastomoses. All patients underwent preoperative embolization without complications. CBCT fusion images clearly visualized the feeders from each arterial system, the vascular compartments within the tumor, and possible peritumoral anastomoses. This technique provides a substantial contribution to both preoperative embolization and surgical resection of skull base meningiomas.