Resistive Elements Research Articles

Full-Wave 3-D Transient Analysis With Method of Moments and Numerical Laplace Transform Including Resistive Non-Linear Elements

Methods based on both time ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</i> )-domain and frequency ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</i> )-domain have been used for electromagnetic transient (EMT) analysis using both circuit-theory and field-theory approaches. Methods based on circuit theory are fast and convenient but may become inapplicable to many engineering problems due to simplifications such as the transverse electromagnetic assumptions. Moreover, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</i> -domain-based techniques rely on approximate methods to account for frequency dependence, which is an essential characteristic of electric conductors, equipment and soil environment. In this paper, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</i> -domain solutions obtained from the method of moments (MoM) discretization of the electric field integral equation (EFIE) are converted to <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t-</i> domain using the numerical Laplace transform (NLT) by means of post-processing. This circumvents the need to formulate the EFIE and MoM based on the complex frequency which would be required for their application to conventional NLT. Hence, existing MoM implementations can be used to perform a full-wave 3-D EMT analysis for a wide range of power system applications. Examples include energizations of 3-D power system networks with fast and non-vanishing excitations such as step functions, as well as modeling non-linear elements using the piecewise linear approximation. Results from experimental measurements, finite-difference <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</i> -domain method, and EMT-type software confirm the validity of the proposed method for power system transients in the range of microseconds down to nanoseconds.

The Composite Radio Absorbing Material Based on Resistive Rings

The frequency dependences of the effective permittivity of the structure in the form of an array consisting of ring resistive elements that are located in a dielectric layer are obtained. The calculations are based on the solution of the problem of diffraction of an electromagnetic wave normally incident on the structure. The possibility of variation of the dispersion dependences in wide limits by means of changing the structureparameters is shown.

A 1.25–1.8 V reference-free capacitor sample-hold oscillator architecture with 22.19 ppm/°C at 58.9 kHz

This paper presents a capacitor sample-hold oscillator architecture which realizes temperature-stabilized operation without a precise reference generator by using a capacitor to sample-hold the peak charge voltage of the previous phase as the reference for the current phase. Due to its dual-way charging and discharging structure, the peak charge voltage for each phase will eventually stabilized around half the supply voltage. The frequency of the oscillator depends on the RC time constants of capacitors charging (discharging) across passively-temperature-stabilized resistive elements and the comparator delay time. By analyzing the temperature characteristics of the comparator delay time and using temperature compensated bias currents to achieve temperature stabilization of the delay time, this architecture improves the overall temperature stability. This architecture has been designed and verified in 0.18-μm CMOS technology. The simulation results demonstrate this design consumes 7.99 μW from a 1.8 V supply voltage at 58.9 kHz and achieves a temperature stability of best 22.19 ppm/℃(TT Corner) from −40◦C to 90◦C, and frequency variations of ± 0.3 % for supply changes from 1.25 to 1.8 V.

Software Engineering of Resistive Elements Electrophysical Parameters Simulation in the Process of Laser Trimming

This study continues a series of papers covering the R&amp;D of circuit simulators embedded into manufacturing equipment for the laser trimming of film and foil resistors intended to improve the final product’s performance and reduce process costs. Our paper describes the development of the ResModel laser trimming simulation software. Various types of trims and their features are presented for a circuit with a dynamic measurement DC source, and the optimal trim configurations are identified. The software can be used to estimate and display resistive element properties during the trimming such as its electrophysical parameters and their trends.

Organic amendment treatments for antimicrobial resistance and mobile element genes risk reduction in soil-crop systems

Agricultural fertilization with organic amendments of animal origin often leads to antibiotic resistance dissemination. In this study, we evaluated the effect of different treatments (anaerobic digestion, biochar application, ozonation, zerovalent iron nanoparticle application, and spent mushroom substrate addition) on the resistome in dairy cow manure-derived amendments (slurry, manure, and compost). Anaerobic digestion and biochar application resulted in the highest reduction in antibiotic resistance gene (ARG) and mobile genetic element (MGE) gene abundance. These two treatments were applied to cow manure compost, which was then used to fertilize the soil for lettuce growth. After crop harvest, ARG and MGE gene absolute and relative abundances in the soil and lettuce samples were determined by droplet digital PCR and high-throughput qPCR, respectively. Prokaryotic diversity in cow manure-amended soils was determined using 16S rRNA metabarcoding. Compared to untreated compost, anaerobic digestion led to a 38% and 83% reduction in sul2 and intl1 absolute abundances in the soil, respectively, while biochar led to a 60% reduction in intl1 absolute abundance. No differences in lettuce gene abundances were observed among treatments. We conclude that amendment treatments can minimize the risk of antibiotic resistance in agroecosystems.

Individuals' attitudes about organizational change: relationship between BPM and resistance to change

PurposeThe aim of this article is to investigate individuals' attitudes about organizational change, considering implementation of business process management (BPM) and resistance to change.Design/methodology/approachThe study examines the attitudes of subjects that experienced organizational change in the context of BPM in Brazil. In order to measure resistance to organizational change, 22 interviews were conducted using a script adapted from Pereira et al. (2019). The study considered two main agents: BPM implementers and end-users. Data were analyzed qualitatively via content analysis.FindingsThe results provided interesting insights. In relation to the individuals' attitudes, satisfaction, fear, stress and anxiety were the most frequently reported. However, opinions contradict the negative feelings expressed, given that organizational benefits, facility and pleasure at work and personal benefits were the most frequently reported. In regard to behavior, individuals approved change and in general accepted it. Finally, in terms of confidence in management, the subjects reported leadership and trusting their bosses as positive points.Research limitations/implicationsStudy limitations include the difficulty in finding end-users on LinkedIn, the fact that convenience sampling was used and the possible false memory of respondents.Originality/valueThe approach used in this study provided a relevant contribution to the area under study, primarily via the new findings, that is, elements of resistance to change that emerged from the data.

Trends in carbapenem resistance in Pre-COVID and COVID times in a tertiary care hospital in North India

BackgroundCarbapenem resistance is endemic in the Indian sub-continent. In this study, carbapenem resistance rates and the prevalence of different carbapenemases were determined in Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa during two periods; Pre-COVID (August to October 2019) and COVID (January to February 2021) in a north-Indian tertiary care hospital.MethodsDetails of patient demographics and clinical condition was collated from the Hospital Information System and detection of carbapenemases NDM, OXA-48, VIM, IMP and KPC was done by Polymerase chain reaction (PCR) in 152 and 138 non-consecutive carbapenem resistant isolates during the two study periods respectively. Conjugation assay and sequencing of NDM and OXA-48 gene was done on a few selected isolates.ResultsAs compared to Pre-COVID period, co-morbidities and the mortality rates were higher in patients harbouring carbapenem resistant organisms during the COVID period. The overall carbapenem resistance rate for all the four organisms increased from 23 to 41% between the two periods of study; with Pseudomonas aeruginosa and Klebsiella pneumoniae showing significant increase (p < 0.05). OXA-48, NDM and co-expression of NDM and OXA-48 were the most common genotypes detected. NDM-5 and OXA-232 were most common variants of NDM and OXA-48 family respectively during both the study periods.ConclusionHigher rate of carbapenem resistance in COVID times could be attributed to increase in number of patients with co-morbidities. However, genetic elements of carbapenem resistance largely remained the same in the two time periods.

ИССЛЕДОВАНИЕ РЕЗИСТИВНОГО ЭЛЕМЕНТА В ЦЕПИ ЗАЗЕМЛЕНИЯ СИЛОВОГО КАБЕЛЯ КАК ДАТЧИКА ЧАСТИЧНЫХ РАЗРЯДОВ

The article discusses the process of modeling a partial discharge (PD) pulse for power cables for an operating voltage of 10 kV, the model makes it possible to evaluate the use of a low-resistance resistive element in the ground circuit as a sensor for registering PD. To achieve the goal, tasks were set to develop a circuit and its simulation. It is determined that the resistor can be used to register PD pulses. It is noted that the choice of the maximum possible resistive element is more appropriate. The use of a resistive element for registering defects is relevant.

Određivanje parametara smičuće čvrstoće na triaksijalnim uređajima

The soil properties are studied in mechanics, that is, the important properties according to which the soil can be classified. Based on mechanics, the information is being obtained on how the tested soil can be used. For example: which soil is favorable for the construction of various types of structures, which soil is favorable for the construction of embankments, etc. There are several ways to determine the elements of internal soil resistance, cohesion and angle of internal friction, using the laboratory tests, among which the most famous are the direct shear test, triaxial compression test and uniaxial compressive strength test. This paper will describe the "CU" triaxial test results.

Saúde da Família, territórios quilombolas e a defesa da vida

Abstract This article presents and debates historical elements of quilombola struggle and resistance as significant aspects for the production of health and defense of life in these territories. We articulate and reflect upon the importance and limits of the Family Health Strategy in the recognition, appreciation and integration of knowledge and practices of quilombola communities to professional health care focusing on their work processes. This study results from a participatory health research developed with workers of a Family Health Strategy in a quilombola community from north of Rio de Janeiro (Brazil) during the COVID-19 pandemic. We concluded that, despite the potential of the Family Health Strategy, the challenges for comprehensive health care in the territory studied tend to compromise the community’s protagonism - especially that of women - and the effectiveness of care. Quilombola knowledge, experiences and ancestral memories of care are not valued within the scope of the Family Health Strategy. These aspects have little impact on territorialized health care and, therefore, far from a public policy of rights.

Wall-mounted electric boilers on semiconductor thermistor PTC heating elements

The improvement of energy efficiency in HVAC equipment makes the greatest contribution to reducing the environmental impact of household technical equipment on the natural environment. Currently, electric water boilers with resistive heating elements have gained the widest popularity for autonomous household heating systems. Thermoresistive semiconductor heating elements (РТС) represent a new direction in the production of electric water heat generators. An experimental wall-mounted electric boiler with РТС thermoresistive heating elements, with a nominal thermal power of 8 kW-h, was investigated. The characteristic of the РТС heating element within the boiler’s heat exchange unit was determined as a function of temperature. The energy efficiency in the power modulation range of 0.65-8.0 kW-h ranged from 0.983 to 0.988. The specific maximum power of the РТС element was 20 watts/cm2, and the hydraulic resistance of the boiler at a flow rate of 1.0 m3/h was 0.38 m.w.c. Electric indirect heating unit, installed in the design of the serial-produced electric boiler, passed the full test cycle and showed higher energy performance than when using a standard indirect electric heating unit with resistive ETH. Considering that РТС elements have significantly higher reliability and service life, it is recommended to release a trial batch of electric wall-mounted boilers for autonomous household heating systems and small industrial facilities.

An Integrated 50 V Boost Controller With Digitally-Assisted MPPT for Submodule PV Applications

This work introduces an integrated maximum power point tracking boost controller for photovoltaic submodule applications. The IC offers a wide input voltage range from 7 V to 24 V, whereas the output voltage is actively limited to 50 V. The presented design utilizes discrete, low-ohmic MOSFETs for the output stage and thus supports input power levels up to 144 W. The converter operates with peak-current-mode control at 300 kHz switching frequency in continuous conduction mode. During light load operation, the control transitions to direct input voltage sensing pulse-frequency-modulation (PFM) with input and output voltage dependent peak inductor current. Moreover, the low-side resistive current sense is explained in detail together with an inductor current replication circuit for precise high-side turn-off. The maximum power point tracker (MPPT) is based on an adjustable resistive sense element and a delta modulator and achieves 99.9 % tracking efficiency, omitting any need for a high resolution analog-to-digital converter (ADC). In addition, the series connection of multiple DC/DC converters is examined. The peak system efficiency measures 98.4 %. The application-specific integrated circuit (ASIC) is manufactured in an 0.18 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\mu$</tex-math></inline-formula> m HV-BCD process and occupies 6.25 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> of silicon area.

The influence of DC voltage on the conductivity of chloroprene rubber-carbon black composites for flexible resistive heating elements.

In order to acquire a flexible resistive heating element in the temperature range for human body heating, the influence of DC voltage on chloroprene rubber (CR) and carbon black (CB) composites has been investigated. Three conduction mechanisms have been found to occur in the range from 0.5 V to 10 V - charge velocity increase due to the increase of the electric field, matrix thermal expansion that results in decreased tunnelling currents and new electroconductive channel formation at voltages above 7.5 V, where the temperature exceeds the matrix's softening point. As opposed to external heating, during resistive heating, the composite exhibits a negative temperature coefficient of resistivity up to an applied voltage of 5 V. The intrinsic electro-chemical matrix properties play an important role in the overall resistivity of the composite. The material shows cyclical stability when repeatedly applying a voltage of 5 V and can be used as a human body heating element.

Klebsiella pneumoniae: an update on antibiotic resistance mechanisms.

Klebsiella pneumoniae colonizes mucosal surfaces of healthy humans and is responsible for one third of all Gram-negative infections in hospitalized patients. K. pneumoniae is compatible with acquiring antibiotic resistance elements such as plasmids and transposons encoding various β-lactamases and efflux pumps. Mutations in different proteins such as β-lactamases, efflux proteins, outer membrane proteins, gene replication enzymes, protein synthesis complexesand transcription enzymes also generate resistance to antibiotics. Biofilm formation is another strategy that facilitates antibiotic resistance. Resistant strains can be treated by combination therapy using available antibiotics, though proper management of antibiotic consumption in hospitals is important to reduce the emergence and proliferation of resistance to current antibiotics.

The universality of eAREs in animal feces suggesting that eAREs function possibly in horizontal gene transfer.

This study aimed to pinpoint the universality of extracellular antimicrobial resistance elements (eAREs) and compare the contents of eAREs with those of intracellular AREs (iAREs) in animal feces, thus laying a foundation for the further analysis of the horizontal transfer of antimicrobial resistance genes (ARGs) in the animal guts. Extracellular DNAs were isolated from the fecal samples of Pavo cristatus (n = 18), Ursus thibetanus (n = 2), two breeds of broilers (n = 21 and 11, respectively), and from the contents of rabbit intestines (n = 5). eAREs were detected by PCR technology. iAREs in P. cristatus and broiler feces were also detected and compared with the corresponding eAREs. In addition, some gene cassettes of class 1 integrons were sequenced and analyzed. The results showed that eAREs exist in animal feces and intestinal contents. In this study, different eAREs were detected from animal feces and intestinal contents, and tetA, tetB, sul1, sul2, class 1 integron, and IncFIB presented the highest detection rates. The detection rates of certain eAREs were significantly higher than those of parallel iAREs. The integral cassettes with intact structures were found in eAREs, and the cassettes carried ARGs. The presented study here sheds light on the presence of eAREs in animal feces or guts, and eAREs may play an important role in the horizontal gene transfer of ARGs.

Antibiotic resistance in urban stormwater: a review of the dissemination of resistance elements, their impact, and management opportunities

Traditional stormwater infrastructure facilitates the transport of antibiotic resistance genes while green stormwater infrastructure may capture the genes and promote horizontal gene transfer.

Superconducting source and sensor of single bubbles to study nucleate boiling of liquid helium

Joule heat generated by resistive elements of cryogenic micro- and nanodevices often originates boiling of the cooling cryogenic liquids (helium, nitrogen). The article proposes an experimental method to explore the dynamics of the formation and development of a single vapor bubble in cryogenic liquid by sensing the temperature change of a superconducting thin-film microbridge being in the resistive state with single phase slip center or line. It serves both the source of heat for generating single bubbles and the surface temperature sensor due to its temperature-dependent excess current. The average bubble detachment rate and the average single bubble volume were experimentally determined for nucleate helium boiling. The obtained values are in good agreement with the data of other authors found in literature.

МОДЕЛИРОВАНИЕ ЕМКОСТНОГО ДАТЧИКА ДЛЯ РЕГИСТРАЦИИ ЧАСТИЧНЫХ РАЗРЯДОВ В СИЛОВОМ КАБЕЛЕ

The article discusses the simulation of a partial discharge (PD) pulse in a power single-core coaxial cable using a capacitive sensor. The sensor provides capacitive coupling to the test sample and its capacitive element is in fact part of the total capacitance of the cable. The resistive element added to the design makes it possible to register current pulses of partial discharges. At the same time, the used sensor has no connection with high-voltage electrodes of the systems, which is its undoubted advantage in comparison with conventional capacitive sensors.

VARIABLE RADIUS HELIX POTENTIOMETER: PRACTICAL ISSUES

Recently a new approach to constructing potentiometers with non-linear taper was proposed. Its main idea is to reach a non-linear dependence of output voltage on rotation angle using a helical resistive element with variable radius of the helix and cross-section. As it has been shown before, problem of calculation of such potentiometer has a solution for all continually differentiable tapers, but the usefulness of this construction is still unknown. In the current paper we review historical and modern types of potentiometers, including non-linear ones; materials for manufacturing such pots; possible tapers for this type of construction; potential applications. In section 1 potentiometer constructions and materials are analyzed. Most suitable constructions for implementation of variable-radius-helix approach are chosen. A generic way for manufacturing mandrel and resistive element using modern machining tools with computer numeric control. In section 2 tapers for potentiometers with several predefined mandrel shapes are calculated. A comparison between appropriate taper bounds for VRH potentiometer and a conventional multi-turn with variable wirewound pitch is carried out. In section 3 different fields of potentiometer applications are reviewed, including usage of potentiometer in new works on robotics. VHR potentiometer is proposed for use in a manual control system for vehicle cab heating controllinstead of a potentiometer with piecewise-linear taper. In section 4 conclusions are made on perspectives of this type of potentiometer, its pros and cons. Main tasks for further research are outlined.

Safety Evaluation of Bacillus subtilis IDCC1101, Newly Isolated from Cheonggukjang, for Industrial Applications.

The present study aimed to evaluate the safety of Bacillus subtilis (BS) IDCC1101, newly isolated from Cheonggukjang in Korea. Genome sequencing of BS IDCC1101 was performed to investigate the presence of secondary metabolites, virulence, antibiotic resistance, and mobile elements. Its phenotypic safety analyses included antibiotic susceptibility, enzyme activity, carbohydrate utilization, production of biogenic amines (BAs) and D-/L-lactate, hemolytic activity, and toxicities in HaCaT cells and rats. The genome of BS IDCC1101 consisted of 4,118,950 bp with 3077 functional genes. Among them, antimicrobial and antifungal secondary metabolites were found, such as fengycin, bacillibactin, and bacilysin. Antibiotic resistance and virulence genes did not exhibit transferability since they did not overlap with mobile elements in the genome. BS IDCC1101 was susceptible to almost all antibiotics suggested for assessment of BS's antibiotic susceptibility by EFSA guidelines, except for streptomycin. BS IDCC1101 showed the utilization of a wide range of 27 carbohydrates, as well as enzyme activities such as alkaline phosphatase, esterase, esterase lipase, naphthol-AS-BI-phosphohydrolase, α-galactosidase, β-galactosidase, α-glucosidase, and β-glucosidase activities. Additionally, BS IDCC1101 did not exhibit the production of D-/L-lactate and hemolytic activities. Its toxicity in HaCaT cells and rats was also not detected. Thus, these genotypic and phenotypic findings indicate that BS IDCC1101 can be safely used for industrial applications.