Current Values Research Articles

Differentiation of Regions According to the Standard of Living of the Population

The relevance of this work is determined by the important problems of improving living standards in Russia, increasing the welfare of the population, and reducing poverty. High differentiation of the country’s regions also creates additional risks associated with forming undesirable migration flows of both population and business. Studies show that while being a leader in one area, a region may lag in other areas. It is necessary to determine how interrelated the various indicators of living standards in the subjects of the Russian Federation are. The research methods are based on the analysis of indicators of living standards of the population of Russian regions. In particular, the authors analyzed current and retrospective values, compared the values of indicators in different regions of the country, correlation and cluster analysis. The study formed integral indicators of regional development in five areas that characterize the population’s living standard to carry out calculations. The analysis results showed that there is no significant linear correlation between 22 selected private indicators of living standards in the vast majority of cases. The prospects of the study lie in further identification of ways to improve the situation, considering the specifics of the ratio of various indicators of living standards.

Mathematical model of a DC/DC converter based on SEPIC topology

Objectives. A DC/DC converter based on SEPIC topology is a unipolar electronic device which converts an input positive voltage into a stabilized output voltage of the same polarity. It also has the ability to regulate polarity both below and above the input voltage. The aim of the paper is to analyze the DC/DC converter in its both operation phases, as well as to draw up equivalent circuits and obtain characterizing differential equations using Kirchhoff’s rules for each phase. Each system of differential equations is reduced to Cauchy equations, in order to be further transformed into a limiting continuous mathematical model. Each system of equations is converted into a matrix form and subsequently combined into a single matrix system.Methods. The construction of a limiting continuous mathematical model was accomplished using Kirchhoff’s rules. Multisim software was used for the computer simulation, thus enabling the calculated results of direct currents and voltages to be compared to those of the simulation.Results. Results show that the phase coordinates of the mathematical model tend towards the values of real currents and voltages of the converter at a switching frequency higher than 200 kHz. Fairly good agreement is established between the calculated values of currents and voltages and the values obtained by simulation (with varying fill factor and switching frequency).Conclusions. The resulting limiting continuous mathematical model of the DC/DC converter based on SEPIC topology allows for an estimation of the dependence of the currents flowing through the inductor windings and the voltages across the capacitors on a number of parameters. The limiting continuous mathematical model of the DC/DC converter based on SEPIC topology is the basis for its circuit design and physical-and-mathematical analysis.

Ventilation Management in a Patient with Ventilation–Perfusion Mismatch in the Early Phase of Lung Injury and during the Recovery

Chest trauma is one of the most serious and difficult injuries, with various complications that can lead to ventilation–perfusion (V/Q) mismatch and systemic hypoxia. We are presenting a case of a 53-year-old male with no chronic therapy who was admitted to the Intensive Care Unit due to severe respiratory failure after chest trauma. He developed a right-sided pneumothorax, and then a thoracic drain was placed. On admission, the patient was hemodynamically unstable and tachypneic. He was intubated and mechanically ventilated, febrile (38.9 °C) and unconscious. A lung CT showed massive non-ventilated areas, predominantly in the right lung, guiding repeated therapeutic and diagnostic bronchoalveolar lavages. He was ventilated with PEEP of 10 cmH2O with a FiO2 of 0.6–0.8. Empirical broad-spectrum antimicrobial therapy was immediately initiated. Both high FiO2 and moderate PEEP were maintained and adjusted according to the current blood gas values and oxygen saturation. He was weaned from mechanical ventilation, and non-invasive oxygenation was continued. After Stenotrophomonas maltophilia was identified and treated with sulfamethoxazole/trimethoprim, a regression of lung infiltrates was observed. In conclusion, both ventilatory and antibiotic therapy were needed to improve the oxygenation and outcome of the patient with S. maltophilia pneumonia and V/Q mismatch.

DESIGN AND APPLICATION OF LOW-COST FUSE CURRENT TESTER IN CARS

By measuring the voltage drop on the fuses in vehicles with a multimeter and using the fuse voltage drop cards, it is possible to determine the current drawn by the load based on the color, type, and current value listed on the fuse label. Arduino is a family of microcontroller development devices that are utilized in numerous digital system design applications. In this study, a fuse current analyzer is proposed for measuring the voltage drop across the fuses in a vehicle using an Arduino development board and obtaining the load current. The developed current analyzer can be utilized in automotive electricity and electronics courses, circuit studies, and for determining whether the fuse value on vehicles is sufficient and detecting load current leakage. The proposed system is tested on vehicle fuses, and an approximate 4% mean error rate is determined. This system can be used to perform tests in automotive electrical laboratories, or it can be implemented in the classroom to give students hands-on experience.

Design of the CMS High Granularity Calorimeter trigger primitive generator system

The High Luminosity phase of the LHC (HL-LHC) is planned to begin data taking in 2029, with the instantaneous luminosity expected to increase to 4 times its current value and the average number of particle interactions per bunch crossing increasing by approximately 3.5 times its current value. The current endcap calorimeters in the CMS detector will be replaced by a novel high granularity calorimeter (HGCAL) that will have fine segmentation in both the transverse and longitudinal directions and will be the first such calorimeter specifically optimised for particle flow reconstruction to operate at a colliding-beam experiment. The Level 1 trigger of the CMS experiment will combine the calorimeter data with tracking information to allow particle-flow techniques to be used. The high granularity of the calorimeter leads to about six million readout channels in total, concentrated in one million trigger cells, sampled for the L1 trigger at a rate of 40 MHz. The trigger data volumes will be an order of magnitude above those currently handled in CMS, posing significant challenges for data manipulation and processing. In addition, the trigger algorithms must be able to efficiently reject the huge background rate in the forward region of the detector due to the high pileup environment. The status of the HGCAL trigger architecture and design, as well as the algorithms developed in order to tackled these major issues, is presented here. The data flow is described from the formation and preselection of trigger cells on detector to the generation of two types of trigger primitives off detector, projective towers of energy in the (η, ϕ) plane and three-dimensional clusters of particles. Particle flow will use these 3D clusters, and their formation is described and followed by recent developments in the optimization of their transverse size.

Researches regarding power quality at the hot rolling mills’ power supply

The study described in the paper was carried out through measurements taken at a feed station in a hot rolling line. The aforementioned measures are appropriate for the purpose of analyzing power quality. The measurements were taken using a three-phase power quality analyzer. Measurements were taken for voltage and current values, as well as for active, reactive, and apparent powers. The analysis of the measurements taken indicates that the power quality is affected by the nonlinearity of the load. As a consequence, the level of reactive power becomes higher, leading to a reduced power factor.

Impact of electrical equipment on the power factor

A large proportion of electricity consumers alter the electricity quality through the equipment they use. The alteration is caused by a drop in the power factor, which leads to additional losses in the power grid and additional reactive power costs. In order to identify the consumers’ electrical equipment that alter the power factor, we monitor their electricity use in a production hall looking at the variation of the effective average values of voltages, currents, powers and power factor. The analysis of these records gives us the difference between the power factor and cos φ (the phase difference between phase voltage and phase current in single-phase operation). Our monitoring shows, at the same time, the necessity of an individual analysis of each electrical equipment in the production hall under observation, as well the necessity to locally compensate the power factor.

Synthesis and Characterization of Copper-Nickel Based Metal Organic Framework by Co-Precipitation Methode: Properties and Possible Application

CuNi-BTC was synthesized using the co-precipitation method with precursors copper (II) nitrate trihydrate, nickel nitrate trihydrate, benzene-1,3,5-tricarboxylic acid, and the addition of 10 wt% triethanolamine (TEOA) as a modulator. The synthesis was conducted at room temperature and dried at 60°C for 24 hours. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier-Transform Infrared (FTIR), Brunnauer-Emmet-Teller (BET), and electrochemical measurement are techniques employed for the characterization of the material. The diffraction patterns of CuNi-BTC show similar diffraction peaks of the HKUST-1 at 2θ of 6.7°, 9.5°, 11.5°, and 13.4°, respectively. The morphology of CuNi-BTC has an octahedral shape with a pore on its surface. The BET analyses show that the surface area of CuNi-BTC is 534 m2/g with pore and diameter volumes of 0.044 cm3/g and 1.60 nm, respectively. The nitrogen adsorption-desorption isotherm graph shows the type IV characteristic of a mesoporous material. The electrochemical performance of the material was observed by cyclic voltammetry (CV) methods. The CuNi-BTC has current reduction and oxidation values of 4.46 and 3.38 μA, respectively, and has good stability at various scan rates between 10 – 100 mvs-1.

Design and implementation of a cost‐effective practical single‐phase power quality analyzer using pyboard microcontroller and python‐to‐python interface

AbstractThis work presents the design, development, and performance evaluation of a cost‐effective and practical single‐phase power quality analyzer (SPPQA) using Pyboard microcontroller and Python‐to‐Python interface. The SPPQA offers comprehensive measurements, including voltage/current harmonics up to the seventh order, frequency, voltage and current root mean square values, total power, active/reactive power, power factor, voltage and current crest factor, as well as voltage/current total harmonic distortion. To ensure the accuracy of the SPPQA, a testing procedure was conducted using a test bench equipped with a non‐linear load and a 220‐V power source operating at a frequency of 50 Hz. The obtained results, such as and , are compared with measurements obtained from classical approaches and devices, validating the authenticity and reliability of the SPPQA's performance. The SPPQA demonstrates considerable accuracy and reliability in its measurements, establishing it as an efficient and practical tool for power quality assessment. The ability to measure the seven harmonics of voltage and current, alongside other critical parameters, positions the SPPQA as a practical asset in the academic, industrial, and commercial sectors. The affordability and practicality of the SPPQA make it practical in both academic research and practical scenarios. Utilizers can gain deeper information into power quality through its measurements and harmonics analysis, while also enhancing industrial processes and ensuring a reliable power supply in commercial settings.

A simple solution to the Rietveld refinement recipe problem.

Rietveld refinements are widely used for many purposes in the physical sciences. Conducting a Rietveld refinement typically requires expert input because correct results may require that parameters be added to the fit in the proper order. This order will depend on the nature of the data and the initial parameter values. A mechanism for computing the next parameter to add to the refinement is shown. The fitting function is evaluated with the current parameter value set and each parameter incremented and decremented by a small offset. This provides the partial derivatives with respect to each parameter, along with information to discriminate meaningful values from numerical computational errors. The implementation of this mechanism in the open-source GSAS-II program is discussed. This new method is discussed as an important step towards the development of automated Rietveld refinement technology.

Dimensional quantization in InSb and GaAs in three-zone model

Various cases of size quantization in narrow-gap crystals of cubic or tetrahedral symmetry in the three-band Kane approximation are analyzed. Expressions for the energy spectrum depending on the two-dimensional wave vector are obtained for two different cases, differing in the range of current carrier energy values. The size-quantized energy spectrum of electrons in the conduction band and holes in the subband of light holes in InSb and GaAs semiconductors is analyzed in the three-band Kane model.

Solar fuels design: Porous cathodes modeling for electrochemical carbon dioxide reduction in aqueous electrolytes

The reduction of carbon dioxide emissions is crucial to reduce the atmospheric greenhouse effect, fighting climate change and global warming. Electrochemical CO2 reduction is one of the most promising carbon capture and utilization technologies, that can be powered by solar energy and used to make added-value chemicals and green fuels, providing grid-stability, energy security, and environmental benefits. A two-dimensional finite-elements model for porous electrodes was developed and validated against experimental data, allowing the design and performance improvement of a porous zinc cathode morphology and its operational conditions for an electrolyzer producing syngas via the co-electrolysis of CO2 and water. Porosity, pore length, fiber geometric shape, inlet pressure, system temperature, and catholyte flow rate were explored, and these parameters were thoroughly tuned by using the smart-search Nelder-Mead's multi-parameter optimization algorithm to achieve pronouncedly higher, industrial-relevant current density values than those previously reported, up to 263.6 mA/cm2 at an applied potential of −1.1 V vs. RHE.

To the theory of dimensional quantization in crystals in the Kane approximation

The microscopic mechanism of size quantization of the conduction band and valence band of semiconductors of cubic and tetrahedral symmetry has been theoretically studied in the Kane approximation. It is shown that the matrix Schrödinger equation obtained on the basis of the Kane model cannot be solved analytically for a potential well of an arbitrary profile. Therefore, expressions for the energy spectrum are obtained depending on the two-dimensional wave vector directed along the interface of the heterostructure for various cases that differ in the range of current carrier energy values.

Updated reasoned opinion on the toxicological properties and maximum residue levels (MRLs) for the benzimidazole substances carbendazim and thiophanate-methyl.

In compliance with Article 43 of Regulation (EC) No 396/2005, EFSA received from the European Commission in 2020 a mandate to provide its reasoned opinion on the toxicological properties and maximum residue levels (MRLs) for the benzimidazole substances carbendazim and thiophanate-methyl. Specifically, EFSA was asked to assess whether thiophanate-methyl or carbendazim has clastogenic potential and, in case clastogenic potential can be excluded, to derive toxicological reference values necessary for consumer risk assessment and assessment of maximum residue levels (MRLs). Although these active substances are no longer authorised within the European Union, MRLs were established by the Codex Alimentarius Commission (codex maximum residue limits; CXLs), and import tolerances are in place. Based on the assessment of the available data, toxicological reference values and MRL proposals were derived and a consumer risk assessment was carried out. Some information required by the regulatory framework was found to be missing and a possible acute risk to consumers was identified. Hence, the consumer risk assessment was considered indicative only and all MRL proposals derived by EFSA still require further consideration by risk managers. In October 2022, to ensure that MRLs derived by EFSA in its assessment of 2021 are safe for consumers also in view of endocrine-disrupting properties, EFSA was requested to carry out a follow-up assessment taking into account the scientific criteria for identifying endocrine disruptors (ED). Based on the outcome of the assessment, the experts agreed that the reference values are also covering the concern related to the identified hazards indicative of endocrine disruption for thiophanate-methyl. No further considerations on the impact of the ED assessment on the current reference values were needed for carbendazim since the ED criteria are not met for this substance. Therefore, the risk assessment and the MRL recommendations derived in 2021 are confirmed.

Fatigue performance of riser quality girth welds: Analysis of TWI and DNV's databases

AbstractIn the fatigue design guidelines which focus on welded joints, when the applied loading is of variable amplitude (variable amplitude loading, VAL), the slope of the S‐N curves at endurances above the slope transition point (STP) changes from m to m + 2 in DNV‐RP‐C203 and BS7608. However, the position of the STP is different in BS7608 and DNV RP C203. This results in different calculated fatigue lives and the difference in calculated fatigue life can be significant. In order to provide better guidance to industry on the approach to use for fatigue analysis of girth welds in pipelines and risers specifically, TWI and DNV carried out a project where the ultimate aim was to provide guidance on a common S‐N curve suitable for calculating the fatigue life of girth welds with focus on the slope change area of the S‐N curves. This was attempted by re‐analyzing TWI's and DNV's databases of girth weld fatigue test results and comparing the outcomes. Although it was not possible to agree on a single STP from the analysis carried out, regression analysis of high endurance results from the databases suggest that an STP between the two current values 1E7 and 5E7 may be plausible. This is supported by fracture mechanics analysis, which suggests that the position of the STP depends on the fatigue Class, and the magnitude of the applied stress ranges.

The simulation study of high-performance micro-inductors Based on MEMS 3D coils

With the development of flexible electronics and microsystems, the demand for the miniaturization of electronic components is becoming increasingly urgent. Due to the advantages of miniaturization, low power consumption, and easy integration, the micro-inductors fabricated by microfabrication technology get more and more attention. However, the traditional two-dimensional inductors are no longer able to meet the growing needs of today’s society in terms of occupied areas, inductance values, and packaging costs. So, this paper proposes a three-dimensional structure thin film solenoid micro-inductor based on MEMS and analyzes it by using finite element method (FEM). The simulation focuses on recording the inductance values and quality factors of the micro-inductors with varying parameters in the frequency range of 0-2, 000 MHz. Additionally, the maximum current values corresponding to the micro-inductors with different parameters are recorded at the operating temperature of polyimide, specifically addressing the current-carrying capacity. The simulation result has certain theoretical guidance for high-performance micro-inductors design.

Research on three-level PWM Rectifier without grid voltage sensor

Traditional three-level PWM rectification technology usually uses voltage sensors to sample the grid voltage, and then obtains the angle information of the voltage vector through a phase-locked loop, thereby achieving the d/q axis control function of voltage and current. However, the use of voltage sensors not only increases system costs, but also increases system volume and debugging difficulty. In addition, when the voltage sensor is damaged, it can cause system shutdown and affect system reliability. After analyzing the three-level control method of PWM rectifiers, a sensorless control strategy for grid voltage based on sliding mode observer method is proposed. By using the sliding mode observer method to estimate the amplitude and phase of the power grid voltage at the voltage and current values of each PWM cycle, a phase-locked loop is used to determine the position of its voltage vector. The simulation results all demonstrate that the proposed method can accurately and effectively estimate the voltage vector angle of the power grid, and ensure that the output of the rectification system meets the standard voltage waveform.

The Principles of Controlled DC-Reactor Fault Current Limiter for Battery Energy Storage Protection

The significance of battery energy storage systems (BESS) technology has been growing rapidly, mostly due to the need for microgrid applications and the integration of renewables. Relevant to the importance of utilization of BESS in microgrids, the protection of the BESS during microgrid faults has become a concern too. The short-circuit in a microgrid cause over-current for all of the integrated sources. BESS, as one of the sources in the microgrid, is heavily influenced by fault occurrence. The overcurrent can easily damage power electronic converter switches, battery management systems (BMS), and damage battery banks. Fault current limiters (FCLs) are appropriate protection devices that have been massively studied. This paper proposes a controllable reactor fault current limiter (CRFCL) to protect the BESS against fault currents. The proposed CRFCL can control the fault current value supplied by BESS during a fault condition as a current regulator. It is realized by means of the operation of solid-state switches and series DC reactor behavior. The main achievement of CRFCL is the protection of BESS against fault currents without delay. The simulations of the proposed structure are carried out in a MATLAB/SIMULINK platform, and they are confirmed and validated by experimental test results.

The Role of PET Imaging in Patients with Prion Disease: A Literature Review.

Prion diseases are rare, rapidly progressive, and fatal incurable degenerative brain disorders caused by the misfolding of a normal protein called PrPC into an abnormal protein called PrPSc. Their highly variable clinical presentation mimics various degenerative and non-degenerative brain disorders, making diagnosis a significant challenge for neurologists. Currently, definitive diagnosis relies on post-mortem examination of nervous tissue to detect the pathogenic prion protein. The current diagnostic criteria are limited. While structural magnetic resonance imaging (MRI) remains the gold standard imaging modality for Creutzfeldt-Jakob disease (CJD) diagnosis, positron emission tomography (PET) using 18fluorine-fluorodeoxyglucose (18F-FDG) and other radiotracers have demonstrated promising potential in the diagnostic assessment of prion disease. In this context, a comprehensive and updated review exclusively focused on PET imaging in prion diseases is still lacking. We review the current value of PET imaging with 18F-FDG and non-FDG tracers in the diagnostic management of prion diseases. From the collected data, 18F-FDG PET mainly reveals cortical and subcortical hypometabolic areas in prion disease, although fails to identify typical pattern or laterality abnormalities to differentiate between genetic and sporadic prion diseases. Although the rarity of prion diseases limits the establishment of a definitive hypometabolism pattern, this review reveals some more prevalent 18F-FDG patterns associated with each disease subtype. Interestingly, in both sporadic and genetic prion diseases, the hippocampus does not show significant glucose metabolism alterations, appearing as a useful sign in the differential diagnosis with other neurodegenerative disease. In genetic prion disease forms, PET abnormality precedes clinical manifestation. Discordant diagnostic value for amyloid tracers among different prion disease subtypes was observed, needing further investigation. PET has emerged as a potential valuable tool in the diagnostic armamentarium for CJD. Its ability to visualize functional and metabolic brain changes provides complementary information to structural MRI, aiding in the early detection and confirmation of CJD.

Differential pulse voltammetric immunosensor for direct and label-free detection of VEGF using variable domain of heavy-chain antibody displaying phage

Herein the pioneering label-free electrochemistry-based immunosensor with exceptional sensitivity for the rapid and efficient detection of vascular endothelial growth factor (VEGF) was precisely designed based on the phage display technique. The specific variable domain of a heavy-chain antibody (VHH)-displaying phage against VEGF8–109 was successfully immobilized on Au nanoparticles deposited gold electrode modified by 3-mercapto propionic acid and 11-mercaptoundecanoic acid and then, carbodiimide coupling reaction using N-Hydroxysuccinamide and N-(3-dimethyl aminopropyl)-N′-ethyl carbodiimide hydrochloride. Electrochemical characterizations of the proposed immunosensor were performed by PM-FT-IRRAS, scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy techniques. Electrochemical measurements were performed using differential pulse voltammetry in phosphate buffer containing [Fe(CN)6]3–/4– ions as a probe, where the decline in the peak current value was related to a concentration of the antigen cast on the surface of the immunosensor. Under the optimum conditions (pH 7.4, interval time 20 s, and step potential 0.1 V), a linear range of response for the detection of VEGF8–109 by immunosensor was 0.03–10,000 pg/mL (in log concentration), with a limit of detection of 11 fg/mL. The specificity of the immunosensor was also investigated against some typical blood growth factors. The novel immunosensor was applied to evaluate VEGF levels in human serum specimens clinically. The recommended immunosensor was uncomplicated, reasonably priced, and showed adequate accuracy and specificity, which could be applied in the early diagnosis of tumors.