Common Circuit Research Articles

Design of a space cooling plant from residual energy of ORC-GSHP assisted geothermal power plant at Dholera, Gujarat, India

More than 45% of the nations around the world use geothermal energy for a wide range of direct and indirect applications pertaining to its stable nature. This paper explores the use of geothermal energy for the direct application of space cooling in residential and commercial applications. It introduces a low enthalpy geothermal energy utilizing space cooling system, a complimentary system to the Organic Rankine Cycle (ORC)-Ground Source Heat Pump (GSHP) assisted geothermal power plant. The configuration of the whole system, including the cooling, heating, and common circuits, is discussed. The main components of the space cooling system consist of Plate Type Heat Exchanger (PHE), GSHP, Air Handling Unit (AHU), and ORC. This study also built a mathematical model based on heat transfer for heat exchangers, Coefficient of Performance (COP) of heat pump, and cooling load of the AHU. For system observation and analysis, the experimental data collected over the course of 90 days (March to May) has been used. The results show that geothermal systems can be an effective and efficient way to cool spaces. A room temperature of 18 ℃ is achieved for an outside ambient temperature range from 19 to 46℃ in summer conditions. The system output placed GSHP's COP from 1.6 to 4 and the AHU's average cooling load is 58.29 kWh with a heat exchange effectiveness rate of 0.46. The system with a few modifications can also be utilized for space heating during winter and other direct applications during summer.

14‐4: Efficient Multi‐stage Bayesian Optimization for Optimal Display Circuit Input Signal Design

To correct for threshold variations in the driving transistor, pixel circuits rely on a complex sequence of inputs that drive the circuit through programming and emission phase. In this work we propose a multi‐stage optimization strategy to automate the design of input signals for arbitrary pixel circuits. By solving for the operation phases of pixel circuits separately and in reverse order our algorithm efficiently finds the narrow region of input signal designs that achieve the desired functionality in the large search space. We demonstrate the generality of our algorithm on two common pixel circuits, i.e., 3T1C and 7T1C.

Modeling and Suppression of Zero-Sequence Circulating Current Resonance for Parallel Interleaved Inverters With Bypass Capacitor-Based Leakage Current Mitigation

Connection of the neutral point of the ac capacitor to the midpoint or positive (negative) rail of the dc link is a cost-effective method to suppress the leakage current to ground. However, applying it to a modular parallel interleaved inverter system with the common ac and dc bus will induce zero-sequence circulating current (ZSCC) resonance issue. This paper firstly establishes the common mode equivalent circuit model of the multi-parallel inverters system. Secondly, the generation mechanism of ZSCC resonance is investigated based on the installed impedance model. To guarantee the stable operation, the resonance suppression method which combines the sampling instant shift and phase lag compensation is proposed. The frequency aliasing phenomenon and resultant ZSCC dc offset issue due to the sampling instant shift are further analyzed, and an effective suppression scheme of the ZSCC dc offset is proposed by adding an additional ZSCC dc offset control loop. Finally, the comparative experiments verify the effectiveness of the proposed method.

Modelling and Design of a Dual Depletion PIN Photodiode as Temperature Sensor

Nowadays, optical systems play an important role in communications. Dual depletion PIN photodiodes are common devices that can operate in different optical bands, depending on the chosen semiconductors. However, since semiconductor properties vary with the surrounding conditions, some optical devices/systems can act as sensors. In this research work, a numerical model is implemented to analyze the frequency response of this kind of structure. It considers both transit time and capacitive effects, and can be applied to compute photodiode frequency response under nonuniform illumination. The InP-In0.53Ga0.47As photodiode is usually used to convert optical into electrical power at wavelengths around 1300 nm (O-band). This model is implemented considering an input frequency variation of up to 100 GHz. The focus of this research work was essentially the determination of the device’s bandwidth from the computed spectra. This was performed at three different temperatures: 275 K, 300 K, and 325 K. The aim of this research work was to analyze if a InP-In0.53Ga0.47As photodiode can act as a temperature sensor, to detect temperature variations. Furthermore, the device dimensions were optimized, to obtain a temperature sensor. The optimized device, for a 6 V applied voltage and an active area of 500 μm2, had a total length of 2.536 μm, in which 53.95% corresponded to the absorption region. In these conditions, if the temperature increases 25 K from the room temperature, one should expect a bandwidth increase of 8.374 GHz, and if it decreases 25 K from that reference, the bandwidth should reduce by 3.620 GHz. This temperature sensor could be incorporated in common InP photonic integrated circuits, which are commonly used in telecommunications.

An Overview of Multilevel Inverters Lifetime Assessment for Grid-Connected Solar Photovoltaic Applications

Nowadays, due to advancements in power electronic devices as well as the rise in consumer awareness of the need to protect the environment on a global scale, many people are turning to the use of solar photovoltaic (PV) technology in the distributed power generation side. In the field of power electronics, manufacturers need to develop products that have high lifespans. Power electronic device reliability is important for the maintenance of the device and may be scheduled under that information. Rather than preventing failures, reliability can be improved by predicting them. Even though some research has been conducted over the past few years to investigate the reliability of power electronic devices, the reliability is many common circuits has not been investigated and this leads to a big challenge for researchers. In this review paper, an overview of the grid-connected multilevel inverters for PV systems with motivational factors, features, assessment parameters, topologies, modulation schemes of the multilevel inverter, and the selection process for specific applications are presented. In this paper, the findings of a comprehensive reliability analysis of fundamental multilevel inverters are studied. To evaluate the reliability of three basic multilevel inverters, a calculation is made using each component’s mean time before its failure. Two techniques of computation approximate and exact were used to arrive at the final result. To calculate power losses in temperature-sensitive components such as diodes and switches, MATLAB Simulink is employed. In addition, the concept of oversizing photovoltaic (PV) arrays is presented in this study. This concept proposes that energy output may be increased by increasing the size of the PV array under conditions of poor solar irradiation. Finally, the mission-profile-based and Monte Carlo simulation-based methods process flows are discussed for the accurate lifetime prediction and reliability assessments of PV inverters in a real-time scenario, followed by a conclusion with future work.

Neurocomputational mechanisms of food and physical activity decision-making in male adolescents

We examined the neurocomputational mechanisms in which male adolescents make food and physical activity decisions and how those processes are influenced by body weight and physical activity levels. After physical activity and dietary assessments, thirty-eight males ages 14–18 completed the behavioral rating and fMRI decision tasks for food and physical activity items. The food and physical activity self-control decisions were significantly correlated with each other. In both, taste- or enjoyment-oriented processes were negatively associated with successful self-control decisions, while health-oriented processes were positively associated. The correlation between taste/enjoyment and healthy attribute ratings predicted actual laboratory food intake and physical activities (2-week activity monitoring). fMRI data showed the decision values of both food and activity are encoded in the ventromedial prefrontal cortex, suggesting both decisions share common reward value-related circuits at the time of choice. Compared to the group with overweight/obese, the group with normal weight showed stronger brain activations in the cognitive control, multisensory integration, and motor control regions during physical activity decisions. For both food and physical activity, self-controlled decisions utilize similar computational and neurobiological mechanisms, which may provide insights into how to promote healthy food and physical activity decisions.

115. Lesions That Induce Psychosis Localize to a Common Brain Circuit Involving the Hippocampus

115. Lesions That Induce Psychosis Localize to a Common Brain Circuit Involving the Hippocampus

Brain D2-Like Dopamine Receptor Distribution in Rats with Different Types of Genetic Epilepsy.

The distribution of the D2-like dopamine receptor (D2DR) in the cortex and striatum was compared between rats with absence, audiogenic, or combined genetically determined epilepsy and normal Wistar rats by autoradiography. A significantly lower D2DR binding density was observed in the dorsal and ventrolateral aspects of the nucleus accumbens in epileptic vs. non-epileptic rats. Rats with audiogenic epilepsy additionally showed a higher D2DR density in the dorsal striatum and motor and somatosensory cortex and a lower D2DR density in the ventrolateral part of the nucleus accumbens. The findings indicated that a common neuronal circuit is involved in the pathogenesis of both convulsive and nonconvulsive forms of generalized epilepsy.

Single fuzzy inference based fault detection and classification protection scheme for different types of short circuit faults on double circuit transmission lines

ABSTRACT An intelligent protection scheme based on the single fuzzy inference system and discrete Fourier transform is proposed for the faulty phase detection and classification of faults on the mutually coupled double circuit transmission lines. This proposed protection technique uses the magnitude of the pre-processed current information of the sending end bus only. This is implemented in the MATLAB/Simulink environment on a 400 kV, 50 Hz, and 300 km double circuit power system model. The efficacy of the proposed scheme has been tested by performing a wide range of simulation studies concerning different types of faults (common short circuit faults, cross-country and evolving faults, and high impedance faults) and typical fault scenarios (current transformer saturation, noisy environment, and fault during power swing conditions) with variations in different fault parameters and operating conditions. The results presented confirm that the proposed method detects/classifies all the faults within one cycle time and is reliable with a detection/classification accuracy of 99.75%. It is immune to variations in fault parameters, and different operating conditions, and is not affected by the zero sequence mutual impedance. It does not require any training and communication link. Further, the performance is also appraised with other training-based protection schemes.

Optimal Wireless Power Transfer Circuit without a Capacitor on the Secondary Side

This study proposes an approach to obtain maximum power via wireless power transfer using a single primary-side capacitor. It is shown that higher power is achieved when compared to the common wireless power transfer circuit under resonance with dual (primary- and secondary-side) capacitors. This approach is divided into three phases. By choosing the capacitor and frequency as freely assignable variables, we symbolically obtain a formula that allows us to determine the optimized capacitance and frequency for maximum power. To verify our method, we used a numerical analysis and compared it with an electronic circuit simulation. The symbolic formula is able to maintain maximum power despite changes in load or in the coupling coefficients.

D2-LIKE DOPAMINE RECEPTOR DISTRIBUTION IN THE BRAIN OF RATS WITH DIFFERENT TYPES OF GENETIC EPILEPSY

The study investigated D2-like dopamine receptor (D2DR) binding densities in cortex and striatum between rats with absence and/or audiogenic genetically determined epilepsy and normal Wistar rats by autoradiography. It was shown that D2DR binding density was lower in the dorsal and ventrolateral aspects of nucleus accumbens in epileptic vs non-epileptic rats. Additionally, audiogenic rats had higher motor, somatosensory cortex, and dorsal striatum binding as in contrast with non-audiogenic groups. This data suggests that there is a common neuronal circuit involved in the pathogenesis of generalized epilepsy of both convulsive and non-convulsive forms.

RTMS investigation of resistant Obsessive-Compulsive Related Disorders: Efficacy of targeting the reward system.

Repetitive Transcranial Magnetic Stimulation (rTMS) is not only a therapeutic option but also an investigational tool to explore circuits and subjective dimensions in pathological conditions. Obsessive-Compulsive Related Disorders (OCRDs) shared similarities with Substance Use Disorder (SUD), suggesting the involvement of the reward system. This study aimed to verify the efficacy of targeting the reward system with rTMS in OCRDs. Patients with trichotillomania, hoarding disorder and skin picking disorder were treated with rTMS over the left DorsoLateral PreFrontal Cortex (DLPFC) at 15 Hz, targeting the reward system via the connection with the nucleus accumbens and the ventral tegmental area. All patients were administered with psychometric scales assessing depression symptoms and severity of OCRDs symptoms at the baseline, at the end of the treatment and a 1-month follow-up. Analysis of the results showed a reduction in symptom severity at the end of the treatment in all three groups (p < 0.0001) as well as a reduction in depression symptoms (p < 0.01). Improvements at 1-month follow-up were maintained only in younger patients. Indeed, when changes in scores at the follow-up were analyzed separately for younger (<30 years) and older patients (>60 years), the elderly showed again an increase in symptoms severity, suggesting that the stability of TMS effects over time reduces with age, possibly as an effect of age-related reduction in brain plasticity. This study adopted with promising results a protocol (15 Hz over the left DLPFC) targeting the reward system, typically employed in addictions. These results can be in line with the view of OCRDs as behavioral addictions, suggesting the implication of common circuits, such as the reward system, in the mechanisms at the basis of these disorders.

The Frenet Frame as a Generalization of the Park Transform

The paper proposes a generalization of the Park transform based on the Frenet frame, which is a special set of coordinates defined in differential geometry for space curves. The proposed geometric transform is first discussed for three dimensions, which correspond to the common three-phase circuits. Then, the expression of the time derivative of the proposed transform is discussed and the Frenet-Serret formulas and the Darboux vector are introduced. The change of reference frame and its differentiation based on Cartan's moving frames and attitude matrices are also described. Finally, the extension to circuits with more than three phases is presented. The features of the Frenet frame are illustrated through a variety of examples, including a case study based on the IEEE 39-bus system.

Common Source Amplifier and Ring Oscillator Circuit Performance Optimization Using Multi-Bridge Channel FETs

In this paper the DC, analog/RF device and circuit applications of nanosheet (NS) FET is performed. To enhance power performance co-optimization geometry parameters like NS width (NSW) and NS thickness (NSH) are varied for high performance (HP) and low power (LP) applications. A rise in 1.47x in I ON and a rise of 5.8x in I OFF is noticed with increase in NSH due to enlarged effective width (W eff). In addition, a rise of 3.8x in I ON and a fall of 76.4% in I OFF is noticed with higher NSW. Larger the NSW ensures better transconductance (gm), transconductance generation factor (TGF), cut-off frequency (f T), gain-band width product (GBW), transconductance frequency product (TFP), and intrinsic delay (τ). The optimized supply voltage (V DD) for maximum voltage gain of common source (CS) amplifier and 3 stage ring oscillators (RO) with varied NSW is performed. Moreover, the impact of number of stages (N) of 3 stage RO for better frequency of oscillations (f OSC) is studied towards high frequency circuit applications.

Electrochemical contributions: John Edward Brough Randles (1912–1998)

John Edward Brough Randles (Figure 1) was an English electrochemist who made important contributions to the theoretical background of polarography, cyclic voltammetry, and electrochemical impedance spectroscopy. Many modern techniques of electrochemistry are descended from his work, including cyclic voltammetry, anodic stripping voltammetry, and various types of hydrodynamic voltammetry. The Randles-Ševčík equation applied on linear sweep voltammetry and cyclic voltammetry, and the Randles equivalent circuit used in the modeling of impedance spectra are named after him. The earliest electrochemical work of Randles performed with an oscillopolarograph (cathode ray polarograph) resulted in the development of linear sweep voltammetry.[1, 2] In addition to the experimental work, Randles solved a theoretical problem for expressing the current for diffusion-controlled electrochemical reactions by applying an ingenious graphical method.[3] Another important contribution of Randles to electrochemistry was in the theoretical analysis of Faraday impedance spectra published in 1947.[4] The Randles equivalent circuit has been applied to the analysis of the impedance spectra including interfacial electron transfer (Faradaic component), capacitance and diffusion contributions to the impedance. It became the most frequently used theoretical treatment of impedance spectra. It should be noted that similar results were obtained by Russian scientists Dolin and Erschler in 1940, but the papers published in the Russian language have not been seen by the electrochemical community. The Randles equivalent circuit (Figure 2) is one of the simplest and most common circuit models of electrochemical impedance. It includes a solution resistance, a double-layer capacitor, and a charge transfer or polarization resistance. While the Randles equivalent circuit is frequently sufficient for modeling simple electrochemical systems, it can be used as a starting point for more sophisticated models, for example, based on more resistances and capacitances organized in parallel or in a sequence. It should be noted that John Randles was not only working on solving theoretical problems in electrochemistry, but he was a very good experimentalist. As an example of his experimental work, the Volta potential difference between a mercury droplet and an electrolyte solution measured by Randles can be mentioned.[5] Notably, the great Russian electrochemist Alexander Frumkin had failed to obtain a stable and reproducible result for this kind of measurement. Randles published relatively few papers, but many of them are of great importance and his theoretical treatments of electrochemical systems have been included in all electrochemistry textbooks. The author declares that he has no conflict of interest.

Cascaded multilevel inverter for vertical stabilization and radial control power supplies

This paper presents the analysis and topology selection for the power supplies of the two DTT equatorial in-vessel coils for plasma vertical stabilization and fast radial control. The physics requirements and assumptions are analyzed in order to identify the system specifications. Since the basic configuration with two independent power supply circuits is too vulnerable to fast plasma events as disruptions, a circuit configuration including both coils is introduced. Two successive solutions, with three or two power converters, are proposed to supply such a common circuit. The adopted topology, based on cascaded H-bridge converters with IGBTs, is simulated by means of a simplified circuital model, that also consider the plasma disruptions. The simulation results show that vertical stabilization and fast radial control functions can be simultaneously achieved with two identical power converters and a passive imbalance branch by using a specific current control scheme.

Spatial transcriptomic characterization of COVID-19 pneumonitis identifies immune circuits related to tissue injury.

Severe lung damage resulting from COVID-19 involves complex interactions between diverse populations of immune and stromal cells. In this study, we used a spatial transcriptomics approach to delineate the cells, pathways, and genes present across the spectrum of histopathological damage in COVID-19-affected lung tissue. We applied correlation network-based approaches to deconvolve gene expression data from 46 areas of interest covering more than 62,000 cells within well-preserved lung samples from 3 patients. Despite substantial interpatient heterogeneity, we discovered evidence for a common immune-cell signaling circuit in areas of severe tissue that involves crosstalk between cytotoxic lymphocytes and pro-inflammatory macrophages. Expression of IFNG by cytotoxic lymphocytes was associated with induction of chemokines, including CXCL9, CXCL10, and CXCL11, which are known to promote the recruitment of CXCR3+ immune cells. The TNF superfamily members BAFF (TNFSF13B) and TRAIL (TNFSF10) were consistently upregulated in the areas with severe tissue damage. We used published spatial and single-cell SARS-CoV-2 data sets to validate our findings in the lung tissue from additional cohorts of patients with COVID-19. The resulting model of severe COVID-19 immune-mediated tissue pathology may inform future therapeutic strategies.

Lesion network localization of depression in multiple sclerosis

Multiple sclerosis (MS), a demyelinating disease that causes focal white matter lesions, is commonly associated with depression. However, it remains unclear whether depression risk is selectively increased by specific white matter lesion locations. Recent work shows that stroke lesions and therapeutic neuromodulation sites that modify depression severity are connected to a common brain circuit, providing an a priori template. Here we assessed whether this circuit is relevant for white matter lesions in MS. In a clinical and radiological database of individuals with MS (n = 281), we estimated the whole-brain connectivity of each person’s white matter lesion locations using a normative connectome database (n = 1,000). Functional connectivity between MS lesion locations and our a priori depression circuit was correlated with depression severity in MS (P = 0.013) and specific to depression versus other MS-related symptoms (P = 0.0058). A data-driven circuit for MS depression showed similar topography to our a priori depression circuit (P = 0.015). The peak of this data-driven MS depression circuit was in the ventral midbrain, including the ventral tegmental area (familywise-error-corrected P < 0.05). These findings lend insight into the localization of MS depression that may help guide targeting for therapeutic brain stimulation. Using lesion network mapping, Siddiqi, Kletenik et al. have identified a white matter lesion network for depression in people with multiple sclerosis.

Transmission Lines in Capacitance Measurement Systems: An Investigation of Receiver Structures.

Dielectric sensing based on capacitive measurement technology is a favourable measurement approach in many industries and fields of application. From an electrical point of view, a coupling capacitance must be measured in the presence of stray capacitances. Different receiver circuit structures have been proposed for the underlying displacement current measurement. Ideally, the sensor assembly is directly connected to the sensor circuitry to minimize the influence with respect to these parasitic capacitances. However, under harsh operating conditions, e.g., at high temperatures, the sensor and the receiver circuit must be separated in order to protect the electronics. Consequently, the receiver circuit and the sensor have to be connected by cables, e.g., coaxial cables. The measurement setup differs significantly from the ideal design with a direct connection. In this paper, we investigate the behaviour of three common measurement circuits for capacitive measurements in instrumentations with cables. We study the interaction between the sensor and the electronics and analyse the operating behaviour of the circuit, as well as the operating states of the amplifiers used. We also address cross-sensitivities in the sensor design due to stray capacitances. The analyses are carried out for different cable lengths and measuring frequencies, and conditions for the usability of the circuit are deduced. In addition to the operational behaviour, we also evaluate the circuits by means of a noise analyses. Based on this analysis, we show a direct comparison of the circuits. The analysis is based on simulation studies, as well as collaborative measurements on test circuits where all circuit parameters are provided. The test circuits are realized with dedicated state-of-the-art circuit elements and, together with the analysis approach and the results, thus provide a basis for future developments.

Comparative Performance of UPQC Control System Based on PI-GWO, Fractional Order Controllers, and Reinforcement Learning Agent

In this paper, based on a benchmark on the performance of a Unified Power Quality Conditioner (UPQC), the improvement of this performance is presented comparatively by using Proportional Integrator (PI)-type controllers optimized by a Grey Wolf Optimization (GWO) computational intelligence method, fractional order (FO)-type controllers based on differential and integral fractional calculus, and a PI-type controller in tandem with a Reinforcement Learning—Twin-Delayed Deep Deterministic Policy Gradient (RL-TD3) agent. The main components of the UPQC are a series active filter and an Active Parallel Filter (APF) coupled to a common DC intermediate circuit. The active series filter provides the voltage reference for the APF, which in turn corrects both the harmonic content introduced by the load and the VDC voltage in the DC intermediate circuit. The UPQC performance is improved by using the types of controllers listed above in the APF structure. The main performance indicators of the UPQC-APF control system for the controllers listed above are: stationary error, voltage ripple, and fractal dimension (DF) of the VDC voltage in the DC intermediate circuit. Results are also presented on the improvement of both current and voltage Total harmonic distortion (THD) in the case of, respectively, a linear and nonlinear load highly polluting in terms of harmonic content. Numerical simulations performed in a MATLAB/Simulink environment demonstrate superior performance of UPQC-APF control system when using PI with RL-TD3 agent and FO-type controller compared to classical PI controllers.