Circuit Analysis Research Articles

In-vitro testing and circuit analysis of an ultra-miniaturized biosensor for multiple medical implant systems

This paper presents an ultra-miniaturized and flexible biosensor for multiple medical implant systems, operating in the 2.4 GHz Industrial, Scientific, and Medical (ISM) band. A flexible Rogers RO Duroid 3010 material with a dielectric constant (εr) 10.2, loss tangent (δ) 0.0022 and thickness of 0.635 mm is utilised as a substrate and superstrate for the proposed biosensor. The size of an biosensor is 10 mm × 10 mm. Certain design elements are employed to accomplish a miniaturized geometry, such as a slotted radiating patch and ground plane, a flexible substrate and superstrate material. A realistic simulation environment has been utilized to evaluate the performance of the proposed biosensor in multiple tissues, encompassing both homogeneous and heterogeneous situations within different organs. This enables the examination and advancement of the practicality of several implantable applications. The proposed biosensor is validated by making an equivalent circuit. The biosensor exhibits a higher gain of −13.18 dB and a higher bandwidth of 16.52 % at the desired ISM band. To test the practicality of a proposed biosensor, in-vitro measurements have been carried out using different tissue-mimicking phantoms. Moreover, a proposed biosensor’s specific absorption rate (SAR) in multiple tissues has also been calculated. The proposed biosensor demonstrates a good correlation between simulated and measured results, which makes the biosensor an excellent choice for implantation inside multiple medical implant devices.

A Regulatory Circuits Analysis Tool, "miRCuit," Helps Reveal Breast Cancer Pathways: Toward Systems Medicine in Oncology.

A systems medicine understanding of the regulatory molecular circuits that underpin breast cancer is essential for early cancer detection and precision/personalized medicine in clinical oncology. Transcription factors (TFs), microRNAs (miRNAs), and long non-coding RNAs (lncRNAs) control gene expression and cell biology, and by extension, serve as pillars of the regulatory circuits that determine human health and disease. We report here the development of a regulatory circuit analysis program, miRCuit, constructing 10 different types of regulatory elements involving messenger RNA, miRNA, lncRNA, and TFs. Using the miRCuit, we analyzed expression profiling data from 179 invasive ductal breast carcinoma and 51 normal tissue samples from the Gene Expression Omnibus database. We identified eight circuit types along with two special types of circuits, one of which highlighted the significant roles of lncRNA CASC15, miR-130b-3p, and TF KLF5 in breast cancer development and progression. These findings advance our understanding of the regulatory molecules associated with breast cancer. Moreover, miRCuit offers a new avenue for users to construct circuits from regulatory molecules for potential applications to decipher disease pathogenesis.

Volt/VAr Regulation of the West Mediterranean Regional Electrical Grids Using SVC/STATCOM Devices With Neural Network Algorithms

ABSTRACTReactive power compensation is now a challenging issue in maintaining adequate power quality and improving the performance of the transmission system. Many researchers have focused on the behavior of voltage in the unbalanced state, and the majority of the studies have been done with STATCOM. In this study, the increasing power demand in power grids and the challenges associated with maintaining power quality and stability are discussed. The power system in the western Mediterranean region of Turkey is modeled with the DigSILENT Power Factory program using real data. It highlights the importance of reactive power compensation and introduces FACTS devices as a solution to control power factors and reactive power in the grid. In the realistic model, voltage and reactive power regulation is achieved by using SVC and STATCOM devices to ensure voltage stability. A load flow and short circuit analysis is performed on the designed transmission system for a number of critical scenarios. The modeled power system is optimized for the size and location of the FACTS devices by applying genetic algorithms (GAs) and particle swarm optimization (PSO) algorithms to the selected busbars of the FACTS devices, a strategy designed to significantly reduce system losses. The load values used in the heuristics differ from those used in other studies in that they use a realistic load profile that varies randomly and instantaneously over the long term, as opposed to a fixed load profile. All the comparative results show that the STATCOM controller can maintain the most significant reduction in technical losses and excellent performance in controlling the reactive power response under various outages. The effectiveness of the proposed methodology has been validated in various outage scenarios, and it has been shown that it will reduce the total cost of electricity generation in the western Mediterranean region on an annual basis. Considering the results of the Turkish National Transmission System, increasing voltage sensitivity and reactive power control can be beneficial in reducing power transmission costs and maintaining the balance between generation and consumption.

Entropies in Electric Circuits.

The present study examines the relationship between thermal and configurational entropy in two resistors in parallel and in series. The objective is to introduce entropy in electric circuit analysis by considering the impact of system geometry on energy conversion in the circuit. Thermal entropy is derived from thermodynamics, whereas configurational entropy is derived from network modelling. It is observed that the relationship between thermal entropy and configurational entropy varies depending on the configuration of the resistors. In parallel resistors, thermal entropy decreases with configurational entropy, while in series resistors, the opposite is true. The implications of the maximum power transfer theorem and constructal law are discussed. The entropy generation for resistors at different temperatures was evaluated, and it was found that the consideration of resistor configurational entropy change was necessary for consistency. Furthermore, for the sake of generalization, a similar behaviour was observed in time-dependent circuits, either for resistor-capacitor circuits or circuits involving degradation.

Distinct Behavioral Profiles and Neuronal Correlates of Heroin Vulnerability Versus Resiliency in a Multi-Symptomatic Model of Heroin Use Disorder in Rats.

The behavioral and diagnostic heterogeneity within the opioid use disorder (OUD) diagnosis is not readily captured in current animal models, limiting the translational relevance of the mechanistic research that is conducted in experimental animals. The authors hypothesized that a nonlinear clustering of OUD-like behavioral traits would capture population heterogeneity and yield subpopulations of OUD vulnerable rats with distinct behavioral and neurocircuit profiles. Over 900 male and female heterogeneous stock rats, a line capturing genetic and behavioral heterogeneity present in humans, were assessed for several measures of heroin use and rewarded and non-rewarded seeking behaviors. A nonlinear stochastic block model clustering analysis was used to assign rats to OUD vulnerable, intermediate, and resilient clusters. Additional behavioral tests and circuit analyses using c-fos protein activation were conducted on the vulnerable and resilient subpopulations. OUD vulnerable rats exhibited greater heroin taking and seeking behaviors relative to those in the intermediate and resilient clusters. Akin to human OUD diagnosis, further vulnerable rat subclustering revealed subpopulations with different combinations of behavioral traits, including sex differences. Lastly, heroin cue-induced neuronal patterns of circuit activation differed between resilient and vulnerable phenotypes. Behavioral sex differences were recapitulated in patterns of circuitry activation, including preferential engagement of extended amygdala stress circuitry in males and cortico-striatal drug cue-seeking circuitry in females. Using a nonlinear clustering approach in rats, the analysis captured behavioral diagnostic heterogeneity reflective of human OUD diagnosis. OUD vulnerability and resiliency were associated with distinct neuronal activation patterns, posing this approach as a translational tool in assessing neurobiological mechanisms underpinning OUD.

The Application Analysis of Sequential Circuit in the Design of Multifunctional Clock

As time management is getting harder in this fast pace of life, traditional clocks have encountered many problems for its complexity and simple functions because it can also be a problem to integrate multiple capabilities into one device based on mechanical inner structure. Therefore, digital clocks can be a better choice and this experiment intended to provide a way of designing the circuit of a multifunctional digital clock based on components used in sequential circuits. Within the circuit, counter, reversible counter and comparator were applied to realize counting, time-setting, countdown, alarming and on-time alarm functions. In this article, the working principles of main chips and the key designing methods will be introduced. NI Multisim was applied to provide simulated results of the behavior of this clock. The results turned out to meet all expectations even though the experiment had inevitable limitations. Thus, it is suggested that further researches can be conducted to ensure a more energy-efficient and precise clock with more advanced useful capabilities.

Development of Spherical Actuator with L-Shaped Yoke

In this paper, a two-DOF L-shaped yoke spherical actuator based on the principle of traditional voice coil actuators is developed. By utilizing the shape characteristics of the yoke and the magnetization direction of the magnet, the magnetic flux is concentrated and the magnet is shared, thereby improving the performance of the actuator. In the design process, SOLIDWORKS 2018 software is used for design modeling and assembly simulation, ANSYS Maxwell 2018 software is employed for magnetic circuit analysis and electromagnetic simulation, while MATLAB is utilized for analyzing the dynamic characteristics through a mathematical model. A prototype was also fabricated, and torque measurement experiments were conducted to verify the performance and feasibility of the proposed design.

Analysis of RL electric circuits modeled by fractional Riccati IVP via Jacobi-Broyden Newton algorithm.

This paper focuses on modeling Resistor-Inductor (RL) electric circuits using a fractional Riccati initial value problem (IVP) framework. Conventional models frequently neglect the complex dynamics and memory effects intrinsic to actual RL circuits. This study aims to develop a more precise representation using a fractional-order Riccati model. We present a Jacobi collocation method combined with the Jacobi-Newton algorithm to address the fractional Riccati initial value problem. This numerical method utilizes the characteristics of Jacobi polynomials to accurately approximate solutions to the nonlinear fractional differential equation. We obtain the requisite Jacobi operational matrices for the discretization of fractional derivatives, therefore converting the initial value problem into a system of algebraic equations. The convergence and precision of the proposed algorithm are meticulously evaluated by error and residual analysis. The theoretical findings demonstrate that the method attains high-order convergence rates, dependent on suitable criteria related to the fractional-order parameters and the solution's smoothness. This study not only improves comprehension of RL circuit dynamics but also offers a solid numerical foundation for addressing intricate fractional differential equations.

Analysis and Applications of Magnetically Coupled Resonant Circuits

Magnetically coupled resonant circuits have been utilized in radio engineering for many years. Recently, these circuits have found new applications, particularly in supplying low- and medium-power devices through medium-range wireless power transmission technology based on magnetic resonance coupling. There is also a growing need to analyze magnetically coupled resonant circuits in the design of metamaterials, which exhibit specific electromagnetic properties within certain frequency bands. This paper provides a coherent and concise overview of the phenomena associated with magnetically coupled resonant circuits. The results encompass numerous established relations as well as new ones. They can be helpful in the design phase of magnetically coupled resonant circuits. The outcomes include equations for determining the coupling resonant frequencies and some parameters of resonance curves. These analytical results are accompanied by 3D and cross-sectional (contour) graphs for better visualization. Moreover, a lumped-element circuit model that includes magnetically coupled resonant circuits is proposed for the resonators used in metamaterials. Formulas for resonant frequencies are derived in the specific case of exciting such resonators. To validate the accuracy of the derived equations, the analytical results are compared with simulations from SPICE (IsSPICE4 ver. 8.1) and COMSOL 5.4 software, which are widely used tools for circuit analysis and electromagnetic simulations. The results of these comparative analyses indicate that the assumptions employed in the analytical solutions introduce only tiny errors.

Systematic Analysis of Sequential Circuits in Digital clock and It Display Mode Comparison

The design idea of the seven-segment digital tube electronic clock and its potential applications against a contemporary backdrop are the main topics of this study. The seven-segment digital clock's low cost and straightforward design make it popular, especially for gadgets with tight budgets. Accurate time reading, adjustment, countdown, and warning functions are achieved through the study and design of a range of digital circuits, demonstrating the broad application potential of digital logic in time control. The circuit's synchronization, stability, and operability are checked using the Multisim simulation tool, guaranteeing the design's dependability in real-world applications. The findings of the study demonstrate the seven-segment digital clock's long-term utility in particular situations, particularly in settings where affordability and durability are crucial. However, the seven-segment digital clock is also under pressure from competitors due to the growing popularity of new display technologies like OLED and smart technology. According to the research, it can continue to be used in particular industries in the future by merging intelligent characteristics to broaden its range of applications.

Comprehensive Analysis of a Bridged-T Pre-Equalizer Circuit for High-Speed Visible Light Communications

Comprehensive Analysis of a Bridged-T Pre-Equalizer Circuit for High-Speed Visible Light Communications

Transmission Line Modeling-Based Position Sensorless Control for Permanent Magnet Synchronous Machines

Position sensorless control has been widely used in permanent magnet synchronous motor (PMSM) drives in low-cost applications or in the fault-tolerance control of position sensors. Conventional sensorless control methods often adopt a back electromagnetic force (EMF)-based position observer, which results in bandwidth reduction in signal processing and lower estimation accuracy. This paper introduces a numerical solution based on transmission line modeling (TLM) to obtain the back EMF. The TLM method is used for the numerical calculation of electromagnetics due to the clear algorithm structure, robust convergence and stability, and easy implementation in dynamic circuit analyses. This paper first analyzes the 2D TLM method techniques. Then, a new application of TLM theory in position sensorless control of PMSMs is put forward. The proposed TLM-based sensorless control scheme can estimate the back EMF without decreasing the bandwidth, thereby enhancing the dynamic performance of the sensorless control. All numerical results are implemented using the proposed approach, which validates the effectiveness of the proposed method.

Calibration equipment for defibrillator analyzer designed with digital multimeter and oscilloscope

Calibration equipment for defibrillator analyzer designed with digital multimeter and oscilloscope

Design and Analysis of Magnetic circuit for Mass Transfer 6-DOF Magnetic levitation Platform

Design and Analysis of Magnetic circuit for Mass Transfer 6-DOF Magnetic levitation Platform

Analysis, Formulation, and Implementation of a Nonlinear Equivalent Circuit for High-Frequency Semiconductor Diodes

Analysis, Formulation, and Implementation of a Nonlinear Equivalent Circuit for High-Frequency Semiconductor Diodes

Evaluation of Corrosion Potential Stability of Stainless Steels in Dilute Electrolyte Solution for Application to a Quasi-Reference Electrode Used in Electrochemical Sensing System

To evaluate the long term corrosion potential stability of stainless steel (SS) in environmental water, the corrosion potential of SUS304, SUS316, SUS316L, and SUS430 was measured for 1 week in a solution of 0.9 mM NaHCO3 and 0.5 mM CaCl2, referred to as “sub-tap water.” The potential of the SSs upon initial immersion in sub-tap water was approximately 10 times less stable than the potentials of Fe and Cu. However, as immersion continued, the stability of the corrosion potential of the SS improved and became equivalent to those of Fe and Cu. The stability could be manipulated by pretreatment (pre-immersion) before samples were immersed in sub-tap water. The stability was increased by pre-immersion in an acidic solution but was reduced by a passivation treatment. The formation of iron oxides on the SS surface stabilized the potential, whereas surface enrichment with Cr led to instability. This behavior can also be inferred from a comparison of the polarization curves, where the passive current after the passivation treatment was the largest. This result is also speculatively attributed to the corrosion potential in sub-tap water decreasing over time after the passivation treatment. The charge transfer resistance likely contributes significantly to the potential stability, as indicated by an equivalent circuit analysis based on electrochemical impedance spectroscopy. The results showed that, when stabilizing the corrosion potential of SS, there is no need to reduce the charge transfer resistance as with existing reference electrodes. Stability is achieved when the surface thickness is such that the pseudo-capacitance in a dilute solution is less than 10 µF sα−1cm−2 and potential stability does not influence a few changes in the CPE1 value after potential stability is achieved. The results of this study show that SS can be used as a quasi-reference electrode material. We expect the findings presented herein to strongly affect the development of electrochemical sensors that can be easily used in long term continuous measurements and in situ applications.

Structure Design and Optimization of MRE Vibration Isolator

As an intelligent component, the high-performance MRE vibration isolator has great advantages, such as a wide vibration isolation frequency range and good performance in semi-active vibration reduction applications. In order to develop high-performance MRE devices, Firstly, this paper makes use of the advantages of real-time tracking/away from external excitation frequency of MRE devices, analyzes the working mode of MRE, and designs a shear MRE vibration isolator based on airborne equipment. Secondly, the material selection and magnetic circuit analysis of the MRE are also completed, and the magnetic field in the MRE region is maximized under the same input energy, thus improving the working efficiency of the MRE isolator. Finally, the relationship between magnetic induction intensity and structural size variables is established by the finite element method and the structural dimensionless method. Based on COMSOL multi-physics simulation software (version 6.0), the global optimization is carried out, the results show that the optimal solution satisfying the comprehensive index of optimal vibration isolation performance of the MRE isolator is obtained, then the structural parameters of the isolator are optimized, and its magnetic control performance is improved. The MRE vibration isolator designed in this paper meets the vibration isolation requirements of airborne optical equipment and has certain engineering application value.

Munir Gunes Kutlu: Exploring the neural mechanisms of learning and social behaviors – A scientist's journey and perspective

Dr. Munir “Gunes” Kutlu, Assistant Professor at the Center for Substance Abuse Research (CSAR) and the Department of Neural Sciences at Temple University Lewis Katz School of Medicine, investigates the neural mechanisms underlying associative learning, mainly focusing on reward, fear, and social interaction. Drawing from his computational neuroscience training at Duke University and postdoctoral work at Temple and Vanderbilt Universities, Dr. Kutlu combines systems neuroscience, computational approaches, and behavioral analysis to understand how our brains process environmental associations and how these processes can become maladaptive in disease states. His laboratory, dedicated to “bridging the brain-behavior gap,” fosters a collaborative environment that nurtures the next generation of neuroscientists while pursuing innovative neural circuit analysis approaches in reward and aversive learning contexts. In this Genomic Press interview, Dr. Kutlu shares his insights on these fascinating aspects of behavioral neuroscience and his laboratory's mission to advance our understanding of neural circuit function in health and disease.

Performance of YBCO Step Edge Josephson Junctions for Different Film Thickness to Step Height Ratio

Step edge Josephson junction devices of YBa2Cu3O7‐x films on SrTiO3 substrates are fabricated, and the device performance is studied for different t/h (t: the thickness of the film, h: step height) ratios. After depositing YBCO films on the step etched substrates, photolithography, and ion beam etching techniques are used to fabricate three devices with t/h ratios of ≈0.4, 0.7, and 1.2. The critical temperatures (Tc) of the devices are ≈82, 85, and 88 K, respectively. The critical current (Ic) and normal state resistance (Rn) are observed to be t/h ratio dependent. The critical current values at 70 K for the devices with t/h ratios of 0.4, 0.7, and 1.2 are ≈425, 550, and 820 μA, respectively. The IcRn product at 70 K is ≈2.06, 2.76, and 0.43 mV for t/h ratios 0.4, 0.7, and 1.2, respectively, which indicates that the t/h ratio of 0.7 is optimum for the device performance. The current versus voltage curves at 68 K are fitted using the resistively shunted junction model using the Portable Superconducting Circuit Analyzer (PSCAN2) simulator, which suggests that there can be normal conducting links present across the microbridge, and it becomes effective for I > Ic, contributing to excess current.

Triple Helix Molecular Switch Cascade Multiple Signal Amplification Strategies for Ultrasensitive Chloramphenicol Detection.

A novel self-powered biosensor has been developed for the detection of chloramphenicol (CAP) based on difunctional triple helix molecular switch (THMS)-mediated DNA walkers. The biosensor utilizes the CAP aptamer as the recognition element, a DNA walker and capacitor as dual signal amplification strategies, and a digital multimeter (DMM) as the data readout equipment. In the presence of the target, the CAP aptamer in THMS specifically binds with CAP to release a signal transduction probe (STP) and opens the H1 hairpin structure in the biocathode to trigger the DNA walker and form a double-stranded DNA structure. Then, [Ru(NH3)6]3+ is electrostatically adsorbed on the double-stranded DNA structure through electrostatic adsorption and reduced to [Ru(NH3)6]2+ at the biocathode by accepting electrons entering at the bioanode. In DNA walkers, more double-stranded structures are formed, and a higher open-circuit voltage (EOCV) is observed. This self-powered biosensor with a detection limit (LOD) of 0.012 fM exhibits ultrasensitive CAP detection in milk in the range of 0.1-104 fM as well as excellent selectivity, stability, and reproducibility.