Measured Resistance Values Research Articles

Rancang Bangun Grounding Box Soil Treatment Sebagai Media Pengukuran Resistansi Pentanahan untuk Proteksi Pembangkit Hybrid PV – Angin Politeknik Negeri Malang

This study addresses the issue of high resistance in the grounding system of the Savonius-Solar Hybrid Power Plant at Politeknik Negeri Malang, caused by rocky and sandy soil conditions, with an initial resistance value of 35 Ω. The purpose of this research was to test the effectiveness of soil treatment using bentonite, charcoal, and salt in reducing resistance to meet the PUIL 2011 standard (<5 Ω). This study employed an experimental method with a quantitative approach, measuring resistance values before and after soil treatment application using a three-point earth tester.The results showed that soil treatment successfully reduced the soil resistance from 35 Ω to 2.85 Ω, meeting the maximum standard. This finding indicates that soil treatment is effective in improving the safety and reliability of grounding systems, making it beneficial for application in similar electrical systems located in areas with challenging soil characteristics.

Investigating the electrical and thermal properties of Cu and Al-doped ZnO thick films using the screen-printing technique for thermal resistance applications

The important properties of prepared Zinc Oxide (ZnO) thick films were investigated. The electrical and thermal properties of ZnO thick films were measured and analyzed using the MATLAB simulation tool. On a glass substrate, thick films of pure ZnO as well as ZnO doped with Cu and Al materials were fabricated using the screen-printing technique. The electrical parameters were calculated using the half-bridge approach to determine the unknown resistance, change in current, and voltage. The half-bridge circuit having a 50 M Ω reference resistance with 30 V excitation voltage. The thermocouple transducer (K type) was used to measure the heating and cooling temperature between 40 °C to 370 °C. The measured maximum TCR values are 0.0095 ppm/°C for pure ZnO film, 0.0068 ppm/°C for Cu-doped ZnO film, and 0.0123 ppm/°C for Al-doped ZnO film. The maximum measured resistance values are 5.9 × 107 Ω for pure ZnO film, 5.9 × 107 Ω for Cu-doped ZnO film, and 5.9 × 107 Ω for Al-doped ZnO film. Using MATLAB simulation, it was possible to observe key factors including the activation energy, unknown resistance, IV characteristics, thermal properties, temperature coefficient resistance (TCR) and resistive linear behavior of the ZnO films.

Study of reading errors when calibrating analog ohmmeters

The features of calibration of analog ohmmeters are considered. Two measurement schemes for calibration were studied: using a multivalued standard measure, which makes it possible to set the ohmmeter readings to the calibrated scale mark, and by a direct measurement of the resistance value of a standard single-valued measure using a calibrated ohmmeter. It is shown that in the first case, the reading error includes two components: the error due to the phenomenon of parallax and the error in aligning the ohmmeter needle with the calibrated scale mark. In the second case, instead of the last component, it is necessary to take into account the interpolation error. Expressions for the uncertainty evaluation of corrections for all components of the reading error for linear and nonlinear ohmmeter scales are given. Formulas have been obtained that make it possible to calculate the measured resistance value in the event that the ohmmeter needle falls between the marks of a nonlinear scale.

Alat Peringatan Dini Bencana Tanah Longsor Dengan Metode Geolistrik

Resistivity or resistivity of the soil. Earth is assumed to be a sphere that is isotropically homogeneous. With this assumption, the measured resistivity is the true resistivity and is independent of the electrode spacing. But in reality the earth consists of different layers so that the measured potential is the effect of these layers. Then the measured resistivity value is not just a single layer resistivity value, but several layers, this is especially true for wide electrode spacing.

Mechanical, thermal, electrical, and corrosion properties of microwave-sintered Ti-0.8Ni-0.3Mo/TiB composites

In this study, Titanium boride (TiB) reinforced Ti-0.8Ni-0.3Mo/XTiB (X = 5, 10, 15, and 20 wt%) composites were successfully fabricated by microwave sintering assisted powder metallurgy process. Scanning electron microscopy (SEM) coupled with energy-dispersive spectroscopy (EDS) and x-ray diffraction (XRD) analyses were used to evaluate the elemental powders individually. The distribution of TiB particles in the sintered Ti-0.8Ni-0.3Mo composites was observed using optical microscopy (OM) and SEM. The Microhardness of the microwave-sintered samples was evaluated through Micro Vicker’s hardness testing machine. Thermal characteristics were estimated for temperatures ranging from 50 to 250 °C. The electrical conductivity of Ti-0.8Ni-0.3Mo/TiB composites was calculated from the measured resistance values using the four-point probe method at room temperature. The immersion method was performed to estimate the corrosion properties by suspending the sintered samples in 3.5% NaCl solution for 60 h. The morphology of the corroded surfaces was examined using SEM. The results revealed that Ti-0.8Ni-0.3Mo/15TiB possessed optimum hardness values from 220 to 260 HV, mechanical properties such as True yield strength from 728 to 814 MPa, ultimate compression strength from 1335 to 1680 MPa, fracture strain of 6.12 to 13.81%. It also revealed less weight loss in a corrosion medium of 0.6 g. The Ti-0.8Ni-0.3Mo/TiB composites had good properties in densification aspects, which is suitable for applications such as marine and airfare components.

Consistent optical and electrical determination of carrier concentrations for the accurate modeling of the transport properties of n-type Ge

A consistent methodology is presented to extract carrier concentrations in n-type Ge from measurements of the infrared dielectric function and the Hall effect. In the case of the optical measurements—usually carried out using spectroscopic ellipsometry—the carrier concentration is affected by the doping dependence of the conductivity effective mass, which is computed using a model of the electronic density of states that accounts for non-parabolicity and is fit to electronic structure calculations. Carrier concentrations obtained from Hall measurements require a knowledge of the Hall factor, which is arbitrarily set equal to unit in most practical applications. We have calculated the Hall factor for n-Ge using a model that accounts for scattering with phonons and with ionized impurities.We show that determinations of the carrier concentration n using our computed effective mass and Hall factor virtually eliminates any systematic discrepancy between the two types of measurement. We then use these results to compute majority carrier mobilities from measured resistivity values, to compare with measurements of minority carrier mobilities, and to fit empirical expressions to the doping dependence of the mobilities that can be used to model Ge devices.

Additive Manufactured Strain Sensor Using Stereolithography Method with Photopolymer Material.

As a result of the developments in additive manufacturing (AM) technology, 3D printing is transforming from a method used only in rapid prototyping to a technique used to produce large-scale equipment. This study presents the fabrication and experimental studies of a 3D-printed strain sensor that can be used directly in soft applications. Photopolymer-based conductive and flexible ultraviolet (UV) resin materials are used in the fabrication of the sensor. A Stereolithography (SLA)-based printer is preferred for 3D fabrication. The bottom base of the sensor, which consists of two parts, is produced from flexible UV resin, while the channels that should be conductive are produced from conductive UV resin. In total, a strain sensor with a thickness of 2 mm was produced. Experimental studies were carried out under loading and unloading conditions to observe the hysteresis effect of the sensor. The results showed a close linear relationship between the strain sensor and the measured resistance value. In addition, tensile test specimens were produced to observe the behavior of conductive and non-conductive materials. The tensile strength values obtained from the test results will provide information about the sensor placement. In addition, the flexible structure of the strain sensor will ensure its usability in many soft applications.

Удосконалення приладу для визначення показника питомого електричного опору коксу .

The two-probe method is the most acceptable for an objective assessment of the resistivity of coke, as it allows obtaining a representative sample with minimal time and labor. However, the standards developed on the basis of this method are characterized by large values of random errors, difficulties in taking them into account and eliminating the influence of transient electrical resistances between the electrodes and the coke powder sample due to the inability to ensure the stability of the bulk mass of its column at constant pressure. Elimination of the influence of transient resistances on the measurement result was ensured by improving the pressing unit and the design of the two-probe matrix, as well as replacing the potentiometer, milliammeter, voltmeter, rheostat and battery with a modern measuring unit. DSTU 8831:2019 was developed and put into effect, which makes it possible to obtain the most reliable results of the coke resistivity. To determine the value of the absolute total error, a series of measurements were made on industrial coke from two leading coke plants in Ukraine and laboratory coke produced in the experimental coke oven of the SE "UKHIN" with electric heating. The obtained results show that the values of the resistivity determined from the same sample but at different size classes differ significantly. The requirement to limit the content of the prepared analytical sample to a class of less than 0.05 mm is substantiated. In several cases, the resistivity of samples with the same volatile yield differs significantly, which confirms the thesis that the resistivity of coke is related to its readiness. The confidence interval of the measured resistivity values is significantly lower than its limit value provided by the standard. This makes it possible to use the improved device in studies of the resistivity of coke. Keywords: hard coal coke, resistivity, determination method, measurement error, coke readiness. Corresponding author I.V. Shulga, e-mail: ko@ukhin.org.ua

Setup for electrical resistance measurement for laser material deposition with coaxial wire feed and use for process control

Within laser additive manufacturing (directed energy deposition with laser beam), processes are further distinguished by the form of the filler material. In terms of availability, storage, safety, and cost, wire is commonly the preferred filler material in comparison to powder. Despite these advantages, due to the different material transfer modes, a greater process control is required. Within this work, an experimental setup for electrical-resistance-measurement within the laser material deposition process with a coaxial wire feed and its possible use for an automated process control is investigated. The measurement is performed between a wire, a substrate, and over the melt pool. One main influencing factor on process stability is derived from the timing of the trigger sequence of the laser power, process feed, and wire feed at the start and end points of every track. Consequently, inaccurate settings of the trigger sequence can, e.g., lead to deviations in track length and part geometry. Additionally, a smooth transfer of the wire into the melt pool is imperative during part build-up to ensure a stable deposition process. Variation in laser power, wire feed, process feed, or wire transfer mode can lead to process instabilities. This can result in imperfections, bonding defects, or pores in the tracks and layers that will add up in built components and must be avoided for defectfree three-dimensional geometries. Within the experiments, it is investigated whether the resistance-measurement provides consistent results under varying conditions and potentially can be utilized to automate the trigger sequence of deposition. Furthermore, it is investigated whether different wire transfer modes can be linked to the measured resistance values during welding of single tracks.

Detection of groundwater sources in Lembor village using geoelectrical resistivity method schlumberger configuration

Drought is one of the problems faced by the people of Lembor Village, Lamongan Regency, this problem will be slightly resolved if the area has reserves of groundwater sources. Therefore, this study aims to determine the existence of potential groundwater sources around Lembor Village. The method used is the geoelectrical resistivity method schlumberger configuration. Data acquisition was carried out for 10 measuring points of Vertical Electrical Sounding (VES) with a track length of 310 meters, and a distance between electrodes of 10 meters. The measurement results are then correlated between VES points to produce a 2-dimensional cross-section. The results showed that the measured resistivity value was between 0.03 Ωm to 81.1 Ωm. The structure of the subsurface layer of the study area is dominated by clay and limestone. The indications for the presence of groundwater are found at a depth between 25 to 35 meters at a track distance of 35 to 45 meters, a track distance of 170 to 180 meters, and a track distance of 270 to 280 meters with resistivity values between 0.03 Ωm to 0.32 Ωm. The indications of the presence of groundwater sources need to be investigated in a wider area, to determine the distribution and direction of groundwater flow.

Dopant Activation Depth Profiling for Highly Doped Si:P By Scanning Spreading Resistance Microscopy (SSRM) and Differential Hall Effect Metrology (DHEM)

Heavily n-doped epitaxially grown Si layers are of great importance for source/drain (S/D) application in advanced node nMOS devices. For contact resistivity reduction, the dopant activation level is very important. Various techniques are being used to evaluate dopant activation in Si:P layers. Among these two methods are Scanning Spreading Resistance Microscopy (SSRM) and Differential Hall Effect Metrology (DHEM). SSRM uses an atomic force microscope equipped with a hard conductive probe that is scanned in contact mode on the cross-sectioned sample’s surface and measures spreading resistance. Measured resistance values as a function of depth are converted into resistivity and carrier concentration depth profiles using calibration measurements and conversion relationships. DHEM provides depth profiles of mobility, resistivity and carrier concentration through a semiconductor layer by making successive sheet resistance (Rs) and Hall voltage measurements using Hall effect/Van der Pauw techniques, as the electrically active thickness of the layer is reduced through successive oxidation steps. Controlled oxidation is achieved by electrochemical anodization. Data collected can then be processed to yield the depth profiles. In this contribution we have carried out SSRM and DHEM measurements on Si:P epi layers subjected to different processing conditions including annealing and ohmic contact fabrication. Secondary Ion Mass Spectrometry (SIMS) was used to measure the total (active + inactive) dopant profiles through the films. Effects of these processes on dopant diffusion and activation were studied and the results from DHEM and SSRM were compared.In-situ phosphorus (P) doped Si epi-layers were grown over 300mm diameter boron doped monitor wafers. While one set was kept as the reference, a second set was treated by a spike-annealing process at 1000 °C. In a third set a Ti/TiN contact fabrication process was carried out and the contact was removed before analysis. In the fourth set contact process was applied to the spike annealed wafer before removal of the Ti/TiN layers. Bulk sheet resistance measurements were made using 4-point probe (4PP) for all the samples. SSRM measurements were carried out at IMEC. Cross-shaped Van der Pauw test-patterns were formed on 8mmx8mm areas on the samples and DHEM measurements were performed at ALP. Figure below shows the dopant depth profiles obtained by SIMS and the carrier concentration profiles from DHEM and SSRM techniques for samples D02 (as deposited Si:P) and D03 (spike annealed). One can make some general observations from the data in this figure. The total dopant concentration as measured by SIMS is ~ 1.4E21/cm3. There is only a small difference in the total dopant distribution profiles (SIMS) between the as deposited sample and the spike annealed sample. However, the spike annealed sample shows much higher dopant activation as measured by DHEM. Carrier concentration is ~2.5x higher in sample D03 (~5E20/cm3) compared to sample D02 (~2E20/cm3). Activation levels measured by SSRM, however, are lower for both samples, and the peak carrier concentration value increases only slightly upon spike annealing, going from ~2E20/cm3 in sample D02 to ~2.2E20/cm3 in sample D03. DHEM clearly indicates the sharp interface between the p-type substrate and the n-type epi-layer and its depth calibration agrees well with the expected thicknesses of the epi layers. The tail of the SSRM data is much more graded. Data from other samples will be presented and discussed in the final manuscript. Figure 1

Geophysical and geological surveys to understand the hydrogeological behavior in an outcrop area of the Guarani Aquifer System, in Brazil

In some Brazilian states, after the long period of drought in the years 2014 to 2015, the issue of water crises became the focus of several studies. Some of these studies propose the use of groundwater to avoid water crises. However, many of these do not understand or ignore the hydrological processes of aquifer recharge and discharge. Understanding the recharge and discharge processes is essential to prevent problems related to aquifers and better understand the exchange relationships between surface and underground reservoirs. Geophysical applications are used to study these hydrological processes of recharge and discharge, however there is a deficit regarding the use of the Electrorestivity method in this type of study. The present work delimited an area close to the escarpment of the Basaltic Cuesta front in the municipality of Ipeúna (SP). The objectives were to understand the recharge and discharge processes using the Electrical Resistivity Tomography (ERT) and a stratigraphic survey. The chosen area is in an outcrop area of the Guarani Aquifer System (GAS), a place known to be important in the recharge of this transboundary aquifer. The stratigraphic survey was carried out by walking along the access road to the study area. In the geophysical survey, 10 parallel lines of electrical resistivity tomography (ERT) were performed in Schlumberger array. The measured resistivity values ranged between 5000 Ω m and 20 Ω m. Data collected in the field were processed and represented in two-dimensional and three-dimensional logarithmic models. Through the correlation between stratigraphy and 2D models, it was possible to locate the porous and fractured aquifers, as well as to relate the resistivity values with the rocks present in the area. The 3D model provided a better visualization of the electrical resistivity values at different depths in the study area. In this way, it was possible to delimit the presence of water in the geological framework. The presence of water inside a large sandstone lens flowing towards the Cuesta front was identified. The geophysical and stratigraphy surveys provided information for the generation of a geological framework model, its relationship with groundwater flow and hydrological processes. The work also reduces the gap of geophysical studies in Guarani Aquifer System and the use of electrical resistivity tomography to understand the hydrological processes of aquifers.

Extracting band-tail interface state densities from measurements and modelling of space charge layer resistance

Dielectric-silicon interfaces are becoming ever more important to device performance. Charge inside a surface dielectric layer is neutralized in Si leading to an accumulation or inversion layer of free carriers. Additionally, states at the interface are occupied by charges via Shockley-Read-Hall carrier statistics. It is accepted that the density of interface charge near midgap, which can only reach a concentration as high as the density of states, Dit, has a minor effect on band bending compared to the charges in the dielectric for a well passivated interface. Here, we show that it is the state density near the band edge what plays the major role. We conclude this by comparing our measurements with device modelling of a Si/SiO2 interface. We measure the wafer sheet resistance while applying various amounts of positive charge to the passivating dielectric on an n-type Si wafer, and then reproduce the measured resistance values using simulations. This modelling indicates that Dit at midgap has indeed a minor effect on sheet resistance change, while the total amount of tail states has a significant impact on the distribution of induced carriers. We test this model to detect the amount of acceptor-like states at the band-tails of oxide passivated silicon with different processing. We discuss and analyse the limitations of this technique. While we report on the Si/SiO2 interface due to its relevance in photovoltaics, our method can be used to study the properties of other semiconductor-dielectric interfaces. As such this work is of importance across various optoelectronic devices.

CORRECTION OF THE TEMPERATURE DRIFT IN THE GEOPHYSICAL INSTRUMENT OF GROUND-BASED INDUCTION FREQUENCY SOUNDING

A technique for correcting the temperature drift in the measurements of the geophysical instrument of ground-based induction frequency sounding has been developed. The device is considered as a measure of the apparent electrical resistivity of the conducting half-space. In the process of manufacturing the equipment, the temperature coefficient of resistance (TCR) of the device is experimentally measured for each frequency separately. The TCR of the device is used to bring the measured resistance values to a certain normalized temperature, for example, 20 °C. The results of the tests performed were processed and systematized using Microsoft Excel. The graphs of the dependence of resistance on temperature are built. The developed methods are intended to improve the accuracy of data processing obtained with the help of equipment operating under conditions of changing ambient temperatures.

Ice slurry flow through a vertical slit channel

The paper presents the results of experimental flow investigations of an ethanol-based ice slurry flowing up and down a vertical slit channel. The impact of flow direction, carrier fluid concentration, ice mass fraction and mean velocity on pressure drop values has been investigated. Stronger mutual interaction between the phases on flow resistances was observed for low carrier fluid concentrations and in the laminar range of ice slurry flow. The measured resistance values for downward flow in the laminar area were 6–10% higher than the pressure drops for upward flow, while in the turbulent flow area they were 1–8% higher. Using the generalized non-Newtonian fluid model, the authors have proposed equations for calculating the friction factors for a vertical slit channel and various flow directions.

Identification of seawater intrusion using geoelectrical resistivity method in the Goa Cina Beach Malang Area, Indonesia

Seawater intrusion can cause groundwater that is looked fresh initially but becomes brackish and even salty. It makes decreasing the quality of groundwater in the area. The Goa Cina Beach, Malang has a geological structure of rock in limestone, sand, and gravel. These rocks have greater porosity, so that the potential to pass water or water infiltration is also quite large, both freshwater and saltwater. Starting from these problems, it is needed to identify groundwater distribution that is not affected by the seawater intrusion process. The geoelectric method effectively determines geological parameters such as depth of bedrock, minerals, fluids, and shallow exploration to identify groundwater aquifers. Data acquisition was carried out using the geoelectrical resistivity method with Wenner configuration with three measurement points. Furthermore, the data processing used Res2dinv Software. The results showed that the measured resistivity value between 0.01000-501 Ωm with a maximum depth of 19.9 meters. The seawater intrusion distribution is assumed to be on lines 1 and 2 at an average depth of 10-19.9 meters with a resistivity value of 0.01000-0.230 Ωm. At the same time, the area that is not expected to experience seawater intrusion is on Line 3. The making of wells for coastal areas needs to consider the distance from the shoreline and rock porosity for minimizing the potential for seawater intrusion.

Truncation method for calculating the resistance of ventilation air-conditioning duct systems under nonfully developed flow boundary conditions

Calculating the resistance of ventilation air-conditioning ducts under nonfully developed flow is a crucial problem that must be addressed. Based on the characteristics of the resistance in ventilation air-conditioning ducts, the truncation method—a computational method that is appropriate for nonfully developed flow boundary conditions—was proposed in this study. The resistance distributions in the upstream and downstream ducts from typical local components, including reducers, bends and tee ducts, were investigated. Using the resistance values of the local components under fully developed flow, the resistances that did not belong to nonfully developed flow were truncated and removed. Finally, the calculation steps of the proposed method were discussed, an engineering case study was presented, and the accuracy of the developed model was analyzed. The results showed that for the local components in the system (reducers, bends and tee ducts), their proportions of the total resistance exhibited similar trends under different width-to-height ratios. The resistance of these local components included upstream resistance, downstream resistance and their own resistance. The upstream resistance accounted for 2%–6% of the total resistance, whereas the downstream resistance of the reducers, bends and tee ducts accounted for 40%–60% of the total resistance. A functional relationship was established between the local resistance and cutoff distance of the reducers, bends and tee ducts. Hence, the truncation method can calculate the local resistance from the cutoff distance. Moreover, in the presented engineering case study, the error between the actual measured resistance values and those simulated with the truncation method was only 4.28%, which was far less than that of the results simulated with the traditional calculation methods (53.64%).

Seeding, Plating and Electrical Characterization of Gold Nanowires Formed on Self-Assembled DNA Nanotubes.

Self-assembly nanofabrication is increasingly appealing in complex nanostructures, as it requires fewer materials and has potential to reduce feature sizes. The use of DNA to control nanoscale and microscale features is promising but not fully developed. In this work, we study self-assembled DNA nanotubes to fabricate gold nanowires for use as interconnects in future nanoelectronic devices. We evaluate two approaches for seeding, gold and palladium, both using gold electroless plating to connect the seeds. These gold nanowires are characterized electrically utilizing electron beam induced deposition of tungsten and four-point probe techniques. Measured resistivity values for 15 successfully studied wires are between 9.3 × 10−6 and 1.2 × 10−3 Ωm. Our work yields new insights into reproducible formation and characterization of metal nanowires on DNA nanotubes, making them promising templates for future nanowires in complex electronic circuitry.

Controlled manipulation of CNTs in glass/epoxy composites with cut-outs using non-uniform electric field

In this work, an effective methodology to incorporate aligned carbon nanotubes (CNTs) in long fiber composites in the presence of geometric discontinuities has been studied. Unidirectional (UD) glass/CNT-epoxy composites containing circular cut-outs were used as representative of a common discontinuity. Multi-walled (MW) CNTs were introduced in the composites via the epoxy matrix and aligned using low-frequency non-uniform AC electric field. This work discusses the methodology to control CNT alignment around the cut-out with the objective of enhancing the stiffness locally. The effectiveness of CNT alignment was assessed indirectly through the mapping of electrical resistance and polarized Raman spectroscopy. A strong correlation was found between the targeted CNT alignment state and the measured resistance values around the cut-out. As a precursor to developing glass/CNT-epoxy hierarchical composites, the response of MW-CNTs in the epoxy resin system was assessed at various input voltage levels in correlation with the weight fraction (wt.%) of CNTs. While a change in electrical resistance by ~3 orders of magnitude was found along the direction of CNT alignment in the hierarchical composites, a change in electrical resistance by ~5 orders of magnitude was observed in the CNT-epoxy composites in comparison with that of the respective control samples.

Improved Calibration Method for Resistive Sensors Using Direct Interface Circuits

Traditional calibration methods for measuring resistance values using a direct interface circuit, comprising a capacitor and some calibration resistors, offer a straightforward, economical option. However, such methods show greater inaccuracies as resistance values decrease. This article presents a modification of the method that ensures more accurate measurements and extends the range of resistance values that can be measured. Unlike the linear equation used in the traditional method, the proposed method obtains the power functions related to resistance value and measured discharge time. Since these circuits need calibration resistors, criteria are established to find their values. To reduce arithmetical complexity, two approximations are tested to calculate the exact value of the resistance. With this approach, the relative errors for low resistances are reduced and the measuring range is extended. Three measurement setups were carried out with a microcontroller and a field-programmable gate array (FPGA) to validate the results, showing the validity of the method independently of the device. Using the FPGA configured so that the maximum current that can be sink per output pin is 24 mA, the error in the estimation of a resistance of $9.9~\Omega $ is ten times less than that obtained using the classic two-point calibration method.