Resistance Values Research Articles

Research on aerodynamic characteristics of high-velocity train bogies

The bogie is a critical component of high-velocity trains. As train velocity rises, the operational quality is increasingly influenced by aerodynamic forces. The aerodynamic characteristics of bogies significantly impact the safety of train operations. This article examines a real high-velocity train model, constructing a 3-group train model, and developing a mathematical model of high-velocity train operation on open lines. Using three-dimensional steady-state Navier–Stokes equations, the flow field characteristics, pressure spread, aerodynamic forces, and torque characteristics on the bogie and body of high-velocity locomotives operating at velocities of 200 km/h, 250 km/h, 300 km/h, and 350 km/h are calculated, with measurement spots set to study the trend of pressure variation with train velocity. The research findings indicate that pressure at the same location on the body surface rises with vehicle velocity, with a quadratic link between the two. The uneven pressure spread between two bogies of the same vehicle and between two axles of the same bogie indicates that aerodynamic forces can cause axle load transfer in high-velocity trains. The highest values of aerodynamic resistance and lift happen at the front bogie, and the resistance and lift of both a single carriage and the entire vehicle increase with velocity, following a quadratic relationship. The highest nodding torque of the train body occurs on one vehicle, while the highest nodding torque of the bogie occurs on the 6th bogie, with both torques increasing with velocity, also in a quadratic relationship.

The Effect of Saccharin on SnNi Alloy: the Electrodeposition and its Electrocatalytic Activity in Ethanol Oxidation Reaction

The development of Direct Ethanol Fuel Cell (DEFC) has attracted much attention, as alternative energy sources due to its various advantages. However, among its various advantages, DEFC has several problems, such as the kinetics of the ethanol oxidation reaction. Transition metal-based catalysts such as nickel and tin are considered as potential catalysts for DEFC due to their oxophilic properties that can improve catalytic activity. In this study, the effect of saccharin on SnNi bimetallic alloy catalyst synthesized by electrodeposition method on copper wire substrate was investigated. SnNi samples were characterized by several techniques, including X-ray diffraction, Scanning electron microscopy, and energi dispersive X-ray spectrocopy. Saccharin addition had a significant effect on the morphology, crystallite size, and composition of the catalyst. The presence of saccharin causes the formation of more uniform particles and has a smaller size. The sample with the addition of saccharin had a smaller charge transfer resistance value 4.82 Ω, lower tafel slope by 115 mV/dec, and show higher jf/jb ratio by 0.55. Furthermore, as the current density decreases, the SnNi catalyst with saccharin has a slow decrease rate and higher stability than the SnNi catalyst without saccharin.

Study of the Technical and Operational Parameters of Injectors Using Biogas Fuel

Using biogas fuel in a modern internal combustion engine equipped with gas equipment of the fourth and fifth generations can create several difficulties. This is due to the low heat of combustion of untreated biogas, the presence of moisture, and the specifics of the injectors. The main problem of the studies we considered is that there are no data on the operating parameters of biogas fuel injectors. Studies on the parameters of the Matrix, Barracuda, Valtek, Hana, and Keihin injectors in relation to biogas fuel were carried out according to performance indicators, the linearity of operation, the resistance of the injectors, the ability to maintain factory parameters, and service life. According to the indicators of performance and linearity of work, Valtek injectors have the highest deviation in productivity and linearity of work, with an average of 38.8%, and the lowest deviation of Barracuda injectors is 7.5%. Keihin (15.3%) and Hana injectors (19.1%) also showed good performance indicators, and therefore can be used effectively for biogas fuel systems. As a result of research on the response time of the injectors, it was established that the best indicators were found for Hana (1.75 ms) and Keihin (1.99 ms) injectors. Valtek injectors showed good response rates (2.07 ms), as did Barracuda injectors (2.19 ms), but the highest response time was found in Matrix injectors, with 2.44 ms. Keihin injectors had the lowest average resistance value of 1.25 ohms, and Valtek injectors had the highest resistance value of 3 ohms. According to the research results, Keihin, Matrix, and Barracuda injectors provide the best ability to maintain factory performance when using biogas fuel at 2 to 5%, and Valtek had the worst performance up to 20%. Keihin, Barracuda, and Hana experimental injectors had the highest service life, which is from 200 to 250 thousand km of car mileage. The lowest indicators were found for Valtek and Matrix injectors, the service life of which varies from 70 to 100 thousand km of mileage.

Graphene nano particles to improve lightning dissipation on transmission lines

Lightning is the primary cause of outages for many high voltage transmission lines. One approach to reduce the frequency of these outages is the improvement of the grounding system using chemical ground enhancers to better disperse transient or fault currents into the soil. In this paper, the objective is to use graphene nano particles to improve the performance of commercial ground enhancers by exploration of 15 different commercial graphene nano particles used to reformulate 19 commercial ground enhancers and one natural ground enhancer. Incorporation of nano graphene particles is by high shear mixing method. The results show reduction in two of the commercial ground enhancers’ resistivity values by a factor of 60. Moreover, lightning impulse tests show that the use of graphene reduce deterioration of the ground enhancer, which can occur after high current events, thereby prolonging its efficacy. Due to the superior electrical conductivity and chemical stability of the graphene, the reformulated ground enhancers improve short-term performance in managing lightning current impulses, and provide a solution, which is likely to perform better over long periods. However, the compatibility of the constituent parts of the formulation is critical to long-term performance.

Geoelectrical resistivity mapping for sustainable groundwater management in Umuahia South: Insights from vertical electrical sounding

The study of geoelectrical resistivity provides critical insights into subsurface characteristics and aquifer dynamics, particularly in regions with varying geological formations. This research investigates the geoelectrical properties of the aquifer system in Umuahia South, highlighting its significance for sustainable groundwater management. The primary aim of this study is to characterize the geoelectrical layers, assess aquifer thickness and resistivity, and evaluate the implications for groundwater resource management. Vertical Electrical Sounding (VES) was conducted across ten locations to measure the resistivity and thickness of subsurface layers. The data collected were analyzed to identify distinct geoelectrical layers, their respective resistivity values, and thicknesses. The study reveals significant variations in aquifer properties across the region, with VES 1 showcasing the largest thickness of 69.2 m and VES 9 the smallest at 5.2 m. Aquifer thickness decreases from the Benin Formation toward the Ameki and Ogwashi-Asaba Formations. Hydraulic conductivity ranges from 0.207 to 0.954 m/day, indicating varying groundwater flow potential, while transmissivity values vary from 4.965 to 30.441 m²/day, with 60% of aquifers classified as intermediate. Groundwater Potential Index (GWPI) highlights approximately 70% of the area as high potential, underscoring the need for targeted management strategies to optimize water resource extraction and sustainability. The variability in resistivity and thickness across the study area suggests significant subsurface heterogeneity. High resistivity values indicate favorable conditions for groundwater flow, particularly in areas like VES 6. Conversely, lower resistivity in locations such as VES 9 indicates potential challenges for groundwater storage. This study provides vital information on the aquifer system in Umuahia South, emphasizing the need for targeted groundwater management strategies based on the geoelectrical characteristics identified. The research contributes to a deeper understanding of the aquifer dynamics in the region and offers a framework for sustainable groundwater resource management, highlighting the importance of geoelectrical assessments.

Metabolomic Analysis of Elymus sibiricus Exposed to UV-B Radiation Stress

Plants cultivated on the Qinghai-Tibet Plateau (QTP) are exposed to high ultraviolet radiation intensities, so they require effective mechanisms to adapt to these stress conditions. UV-B radiation is an abiotic stress factor that affects plant growth, development, and environmental adaptation. Elymus sibiricus is a common species in the alpine meadows of the QTP, with high-stress resistance, large biomass, and high nutritional value. This species plays an important role in establishing artificial grasslands and improving degraded grasslands. In this study, UV-B radiation-tolerant and UV-B radiation-sensitive E. sibiricus genotypes were subjected to simulated short-term (5 days, 10 days) and long-term (15 days, 20 days) UV-B radiation stress and the metabolite profiles evaluated to explore the mechanism underlying UV-B radiation resistance in E. sibiricus. A total of 699 metabolites were identified, including 11 primary metabolites such as lipids and lipid-like molecules, phenylpropanoids and polyketides, organic acids and their derivatives, and organic oxygen compounds. Principal component analysis distinctly clustered the samples according to the cultivar, indicating that the two genotypes exhibit distinct response mechanisms to UV-B radiation stress. The results showed that 14 metabolites, including linoleic acid, LPC 18:2, xanthosine, and 23 metabolites, including 2-one heptamethoxyflavone, glycyrrhizin, and caffeic acid were differentially expressed under short-term and long-term UV-B radiation stress, respectively. Therefore, these compounds are potential biomarkers for evaluating E. sibiricus response to UV-B radiation stress. Allantoin specific and consistent expression was up-regulated in the UV-B radiation-tolerant genotype, thereby it can be used to identify varieties resistant to UV-B radiation. Different metabolic profiles and UV-B radiation response mechanisms were observed between the UV-B radiation-tolerant and UV-B radiation-sensitive E. sibiricus genotypes. A model for the metabolic pathways and metabolic profiles was constructed for the two genotypes. This metabolomic study on the E. sibiricus response to UV-B radiation stress provides a reference for the breeding of new UV-B radiation-tolerant E. sibiricus cultivars.

Parametrical synthesis of various radio devices with the set quantity of identical cascades of type «the nonlinear part – the mixed two-port network»

Background. Presence of possibility of analytical definition of a part of parametres of various radio devices, optimum by criterion of maintenance of preset values of modules and phases of transfer functions on necessary quantity of frequencies, considerably reduces time of numerical optimisation of other part of parametres by criterion of formation demanded frequency response and phase response in a strip of frequencies. Till now such problems dared concerning radio devices only with one cascade of type «a nonlinear part - the coordination the device» or «the coordination the device – a nonlinear part». In quality «the coordination devices were used the jet, resistive, complex or mixed two-port networks. The problem of multicascade radio devices with jet two-port networks is solved also. Change of basis for the coordination two-port networks and a place of inclusion of a nonlinear part leads to change of area of a physical realizability. Aim. Working out of algorithms of parametrical synthesis of radio devices with any quantity of identical and unequal cascades of type «a nonlinear part ‑the coordination the mixed two-port network» by criterion of maintenance of the set frequency characteristics. Nonlinear parts are presented in the form of a nonlinear element and parallel either consecutive on a current or pressure of a feedback. Methods. The theory of two-port networks, matrix algebra, a decomposition method, a method of synthesis of actuation microwave devices, numerical methods of optimisation. Results. In interests of achievement of the specified purpose systems of the algebraic equations are generated and solved. Models of optimum two-port networks in the form of mathematical expressions for definition of interrelations between elements of their classical matrix of transfer and for search of dependences of mixed of two-poles from frequency are received. It is shown, that at certain parities between quantity of cascades and values of resistance of a source of a signal and loading of the one-cascade radio device frequency characteristics of one-cascade and multicascade radio devices appear identical or similar. Such schemes are named by equivalent. Conclusion. The comparative analysis of theoretical results (frequency response and phase response radio devices, value of parametres), received by mathematical modelling in system MathCad, and the experimental results received by схемотехнического of modelling in systems OrCad and MicroCap, shows their satisfactory coincidence.

Evaluating the Impact of Laundering on the Electrical Performance of Wearable Photovoltaic Cells: A Comparative Study of Current Consistency and Resistance

Wearable photovoltaic technology has been prominent in recent years because electronic devices need to be powered continuously without reliance on traditional methods. However, the practical adoption of wearable PV cells is hindered by the need for laundering, potentially degrading performance. This research compared PV cells’ maximum current and electrical resistance before and after laundering testing conditions. This study used eight samples of two types of PV panel cells and laundered them up to five cycles. The current and electrical resistance values were recorded before and after each laundering cycle. This study analyzed the data using a paired sample t-test and MANOVA. It was found that laundering cycles significantly affected the current values in both types of samples, with no differential impact between the types; on the other hand, laundering cycles did not significantly affect the electrical resistance values in both types of samples, with no differential impact between the types. These results are crucial for industries developing textile-based PV panels, where maintaining electrical performance after laundering is essential. These findings could pave the way for more sustainable, self-powered wearable PV technologies, ultimately transforming how users interact with electronic devices daily.

Short-term high-fat and high-carb diet effects on glucose metabolism and hedonic regulation in young healthy men

BackgroundDaily dietary intake of macronutrients and energy is closely associated with long-term metabolic health outcomes, but whether 24-h nutritional intervention under isocaloric conditions leads to changes in metabolism remains unclear. Moreover, the short-term effect of diets with different macronutrient composition on hedonic appetite regulation is less clear.MethodsThis study examined the impact of an acute high-fat (F+) and high-carbohydrate (C+) diet on glucose metabolism and hedonic regulation of food intake in young healthy men under controlled conditions. Using a cross-over design, 19 male participants received a one-day isocaloric diet with different macronutrient composition (F+ = 11% carbohydrates, 74% fat; C+ = 79% carbohydrates, 6% fat) compared to a control diet (CON = 55% carbohydrates, 30% fat). Protein content was set at 15% of energy in all diets. The feeling of hunger, as well as “liking” and “wanting” for foods, was assessed through visual analog scales, and blood samples for glucose, insulin, and cortisol levels were assessed repeatedly during the experimental day. An intravenous glucose tolerance test was conducted the next morning.ResultsPostprandial glucose and insulin levels were lowest in F+ over the 24 h. Except for dinner, the CON diet showed the highest mean values in glucose. F+ diet improved insulin resistance, lowering Homeostatis Model Assessment Insulin Resistance (HOMA-IR) values. Changes in hedonic regulation of food intake were not observed during the intervention between the diets, except for higher feelings of satiety under the CON diet.ConclusionAn acute, isocaloric, high-fat diet improved insulin resistance even in healthy individuals but did not affect hedonic food intake regulation. Macronutrient composition modulate glucose metabolism even under short-term (24-h) and isocaloric diets, which should be considered for personalized preventive dietary treatments.

It's not about building houses; it's about building people's power: Conversation with Carmen and Andrea from the Movimiento territorial de Liberación (MTL) Buenos Aires

This conversation offers a look into the practices of the Movimiento Territorial de Liberación (MTL), a political and social organization in Argentina. It highlights the organization’s history, values, and significant projects, such as housing developments and community initiatives. Founded in 1999 after a break from the Argentine Communist Party over ideological differences, the MTL has its roots in Marxist-Leninist thought. Their work include building neighborhoods and developing collective housing for those displaced by neoliberal policies. The MTL’s projects go beyond merely providing shelter; they aim to foster a way of life that embodies their values of self-management, solidarity, and resistance against capitalist exploitation. Carmen, a leader within MTL, shares their journey, the challenges faced, and the ideological foundations of their work. Andrea, another key figure, manages finances and emphasizes the importance of transparency and accountability in their operations. The conversation also touches on the broader Latin American and global context, situating MTL's struggle within a larger framework of resistance against neoliberalism and imperialism.

Trace‐Amount of Water as An Electrolyte Additive for Sodium Metal Electrode

AbstractThe high reactivity of water toward Na metal has raised a concern about keeping the electrolytes extra‐dried. In this work, changes in water concentration in electrolytes (with and without fluoroethylene carbonate) show changes in overpotential and the surface chemistry of Na electrodes. In a symmetric cell test, the cell with pristine electrolyte (1 M NaClO4 in ethylene carbonate:propylene carbonate) sustained only 22 cycles before reaching the safety limit (5 V) at 1 mA cm−2. Meanwhile, controlling the water content (40 ppm) extended the cell's life by 3.5 times. In fluoroethylene‐carbonate‐containing electrolytes, the optimized water concentration (40 ppm) gave the minimum overpotential (12 mV) after 170 cycles. Ex situ X‐ray photoemission spectroscopy showed that water hydrolyzed fluoroethylene carbonate, which changed the Na electrode's surface chemistry. The appropriate amount of product (NaF) stabilized the electrodes’ surfaces. Electrical impedance spectroscopy showed that the controlled traces amount of water (40 ppm) always gave the minimum values for resistances. For the pristine electrolytes, the resistances attributed to the charge‐transfer process and the solid‐electrolyte interface layer increased 51 times (from 45 Ω–2290 Ω) after cycling. Meanwhile, for the optimized sample, the resistances remarkably decreased by 93 % (from 264 Ω–19 Ω) after cycling.

Novel synthesis of CuHCF/B-rGO composites for oxygen evolution reaction activity

In this work, we have focused on the preparation of copper hexacyanoferrate/boron doped rGO composites (abbreviated as CuHCF/B-rGO) by employing simple co-precipitation technique subsequently processed with ultrasonication method. The XRD spectra confirmed the existence of the cubic structure of copper hexacyanoferrate with high crystalline peaks. The prepared nanocomposite morphology was evaluated by scanning electron microscopy (SEM), and confirmed CuHCF nanoparticles formation with flake-like and wrinkled sheets. Pure CuHCF nanostructures revealed good OER action at 430 mV to obtain 10 mA/cm2. The obtained CuHCF product OER activity can be further upgraded by incorporating the electrically conductive boron doped reduced graphene oxide matrix into CuHCF nanostructures, for the reason that the overpotential of the CuHCF/B-rGO was reduced to 380 mV to attain 10 mA/cm2 with 88 mV/dec Tafel slope value. The doping of heteroatom considerably improves charge-transfer resistance of metal hexacyanoferrate, giving a small resistance value of 2.97 Ω, which was lower than that of CuHCF (5.57 Ω) and CuHCF/rGO (4.31 Ω). Furthermore, the catalytic activity of the CuHCF/B-rGO was stable at prolonged hours with a small decay of 12.5%. Therefore, this work offers new approach to stimulate the catalytic performance of metal hexcyanoferrate by highly conductive carbon-based materials for water splitting performance.

Landslide Identification on Tembalang-Jangli New Road, Semarang, Central Java Using Dipole-Dipole Configuration Resistivity Geoelectric Method

New roads are built to alleviate congestion that occurs in an area. Tembalang is one of the most densely populated areas in Semarang city. The research location is Tembalang-Jangli New Road. The construction of Jangli-Undip New Road aims to reduce congested vehicle traffic in Gombel and Meteseh, which causes frequent congestion. Therefore, subsurface identification using the resistivity geoelectric method of dipole-dipole configuration was carried out to know the cause of landslides at the research location. Data acquisition was carried out with 10 passes. The results obtained 5 (five) layers of subsurface constituent rocks on Undip-Jangli New Road based on their resistivity values, namely topsoil (0.105 - 1.0 Ωm), clay (1.11 - 6.29 Ωm), sandstone (8.52 - 20.0 Ωm), tuff (20.0 - 75.0 Ωm), and volcanic breccia (75.0 - 133 Ωm). The interpretation results show the sliding plane at a 6.76 - 24.8 m depth. The layer that acts as a slide plane is a clay layer. The existence of sliding planes detected in the trajectories A-A’, B-B’, C-C‘, D-D’, E-E‘, F-F’, G-G‘, H-H’, I-I‘, and J-J’ has great potential to cause soil movement or landslides with the type of sliding is rotation. Keywords: landslide, resistivity geoelectricity, dipole-dipole.

Multidimensional analysis of textiles coated with electroactive polymers for actuators

This paper presents a multidimensional analysis of textiles coated with conductive polymers for actuators. The purpose of using multidimensional scaling analysis is to compare similarities and dissimilarities between conductive textiles obtained through conductive polymeric film deposition to observe the optimal value for electrical resistance and to select an adequate method to achieve conductive fabric using different polymers (polyethylene glycol, polyvinyl alcohol or polyvinylidene fluoride) and metal microparticles (copper or nickel). The multidimensional analysis is based on mapping a series of material properties from a proximity matrix (similarities or dissimilarities) between these properties. Multidimensional scaling allows rebuilding the exact map of the values (within approximately a symmetry or rotation). To fit dissimilarity or similarity matrices for multiple variables into one common space estimating the weight parameters for each variable, the INDSCAL model (individual differences multidimensional scaling) was used.

Reset transition in HfO2-Based memristors using a constant power signal

Memristors, also known as resistive switching devices, have great potential for applications in memory and neuromorphic systems. Understanding the switching mechanisms is crucial since ReRAM memories need to operate at high frequencies. It is known the reset transition is dominated by the conductive filament Joule heating. We have studied the reset transition in TiN/Ti/HfO2/W metal–insulator–metal memristors by applying constant power signals to different initial filament thicknesses, which were obtained using different initial low resistance states. The results show that power value controls the reset times, decreasing when the power is increased. On the other hand, larger resistances lead to faster reset transitions. These measurements have allowed us to obtain a value of the thermal resistance of the conductive filament. Moreover, we have observed the reset times as a function of the initial resistance and the power lies on a common plane, which allows us to estimate the transition time by fixing an initial resistance and a power value.

Analysis of the effect of permeant solutes on the hydraulic resistance of the plasma membrane in cells of Chara corallina.

In the cells of Chara corallina, permeant monohydric alcohols including methanol, ethanol and 1-propanol increased the hydraulic resistance of the membrane (Lpm-1). We found that the relative value of the hydraulic resistance (rLpm-1) was linearly dependent on the concentration (Cs) of the alcohol. The relationship is expressed in the equation: rLpm-1 = ρmCs + 1, where ρm is the hydraulic resistance modifier coefficient of the membrane. Ye et al. (2004) showed that membrane-permeant glycol ethers also increased Lp-1. We used their data to estimate Lpm-1 and rLpm-1. The values of rLpm-1 fit the above relation we found for alcohols. When we plotted the ρm values of all the permeant alcohols and glycol ethers against their molecular weights (MW), we obtained a linear curve with a slope of 0.014M-1/MW and with a correlation coefficient of 0.99. We analyzed the influence of the permeant solutes on the relative hydraulic resistance of the membrane (rLpm-1) as a function of the external (π0) and internal (πi) osmotic pressures. The analysis showed that the hydraulic resistance modifier coefficients (ρm) were linearly related to the MW of the permeant solutes with a slope of 0.012M-1/MW and with a correlation coefficient of 0.84. The linear relationship between the effects of permeating solutes on the hydraulic resistance modifier coefficient (ρm) and the MW can be explained in terms of the effect of the effective osmotic pressure on the hydraulic conductivity of water channels. The result of the analysis suggests that the osmotic pressure and not the size of the permeant solute as proposed by (Ye et al., J Exp Bot 55:449-461, 2004) is the decisive factor in a solute's influence on hydraulic conductivity. Thus, characean water channels (aquaporins) respond to permeant solutes with essentially the same mechanism as to impermeant solutes.

Effect of the filler content on some physical and mechanical properties of virgin- and recycled thermoplastic polyurethane composites

Effects of thermoplastic polyurethane (TPU) types (Recycled (R) and Virgin (V)) composites with 15 wt% and 30 wt% oakwood flour addition were studied. Selected physical, mechanical, morphological, and thermal properties of resulting polymer composites were analyzed. Test samples were manufactured using injection molding, except that abrasion resistance specimens were manufactured using a compression molding process. The findings indicated that the types of TPU and filler contents played a significant role in the density and mechanical properties of the TPU test samples. The increased oak wood flour contents in both TPU types showed improvement in density, tensile modulus, hardness, flexural strength flexural modulus, dynamic impact strength, and yield strength of the composite while decreasing the elongation at break values. In addition, both TPU types and filler contents significantly affected the densities of V-TPU and R-TPU. The TPUs type, filler content, and cycle-rpm affected Taber’s abrasion resistance values. Weight loss, which increased with the number of cycles for the control samples, decreased with increasing wood flour content. This study aimed to provide an overview of the effect of the wood flour content in the manufacturing of thermoplastic-reinforced composites and to provide a basis for further research and development efforts.

Low Thermal Resistance of Diamond‐AlGaN Interfaces Achieved Using Carbide Interlayers

AbstractThis study investigates thermal transport across nanocrystalline diamond/AlGaN (aluminum gallium nitride) interfaces, crucial for enhancing thermal management in AlGaN‐based electronic devices. Chemical vapor deposition growth of diamond directly on AlGaN resulted in a disordered interface with a high thermal boundary resistance (TBR) of 20.6 m2‐KGW−1. Sputtered carbide interlayers of boron carbide (B4C), silicon carbide (SiC), and a mixture of boron carbide and silicon carbide (B4C/SiC) are employed to reduce thermal boundary resistance in diamond/AlGaN interfaces. The carbide interlayers resulted in record‐low thermal boundary resistance values of 3.4 and 3.7 m2‐KGW−1 for Al0.65Ga0.35N samples with B4C and SiC interlayers, respectively. STEM imaging of the interface reveals interlayer thicknesses between 1.7 and 2.5 nm, with an amorphous structure. Additionally, Fast‐Fourier Transform (FFT) characterization of sections of the STEM images displayed sharp crystalline fringes in the AlGaN layer, confirming it is properly protected from damage from hydrogen plasma during the diamond growth. In order to accurately measure the thermal boundary resistance we develop a hybrid technique, combining time‐domain thermoreflectance and steady‐state thermoreflectance fitting, offering superior sensitivity to buried thermal resistances. The findings underscore the efficacy of interlayer engineering in enhancing thermal transport and demonstrate the importance of innovative measurement techniques in accurately characterizing complex thermal interfaces. This study provides a foundation for future research in improving thermal properties of semiconductor devices through interface engineering and advanced measurement methodologies.

Electrical Resistivity Tomography and Boreholes Data to Investigate the Near-Surface Structure under the Campus Area of Çanakkale Onsekiz Mart University, Çanakkale, Turkey (Türkiye)

We study the soil foundation underneath the Çanakkale Onsekiz Mart University (ÇOMU) campus, Çanakkale, Türkiye by employing the electrical resistivity tomography – ERT supported by 27 boreholes data. The studied area taking place in southwest Marmara region was historically affected by large earthquakes () created by the North Anatolian Fault system. The boreholes data show that the near surface structure beneath the ÇOMU campus is made of mostly silty sands and marls. A high sensitivity resistivity instrument is used to collect the field data in which nine ERT profiles reaching lengths as long as 315 m are utilized. The current geoelectrical measurements are simulated by using two numerical models to estimate the inversion depth sensitivity from which it is found satisfactory in the depth range 0-30 m and then somewhat decreasing. The observed electrical resistivity values are in the range 2-160 W m. The geoelectrical structure corresponding to the silty sands are represented by low resistivities (<20 W m) while the high resistivity (>40 W m) depth sections are associated with the marl units. The resistivity structure beneath the ÇOMU campus is complex where both low and high resistivity depth sections reside side by side. The groundwater and clay mineralogy contribute to the broad changes in the subsurface resistivities. The groundwater flow below the steep terrain of the ÇOMU campus causes low resistivities (<10 W m) deeper than 10-m depth. The boreholes data superimposed on the two-dimensional (2-D) ERT profiles show consistency with the resistivity-depth distributions at corresponding depths.

Slope Stability Analysis Using Electrical Resistivity Tomography and Limit Equilibrium Method: A Case Study from Girimulyo, Kulon Progo

Girimulyo sub-district is one of the areas with high landslide risk in Kulon Progo Regency. On March 12, 2018, a landslide occurred in the area. Seven families were affected, and landslide material blocked the road. This study aims to determine slope conditions through electrical resistivity tomography (ERT) and slope stability analysis using the limit equilibrium method. Based on the interpretation of the ERT profile, it is known that a layer with a resistivity value of <5 Ωm is wet clay; 5-15 Ωm is wet silt; 15-150 Ωm is silt-to-sand; and >150 Ωm is bedrock. The sliding surface is thought to be at the boundary between the wet clay and wet silt layers. The interpretation of the ERT profile is confirmed by data from laboratory tests on soil samples. Slope stability analysis was carried out using ERT profile interpretation and soil sample laboratory test data. The slope stability analysis results show that both the slopes that experienced landslides in 2018 and those that did not experience landslides were stable when the water table was 3 meters deep. However, the landslide slopes are in critical condition as the groundwater level rises, while the non-landslide slopes are remains stable.