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The effect of annealing treatment on the electromigration (EM) resistance of low-temperature Cu/Sn-57Bi-1Ag (600 μm)/Cu solder interconnects has been investigated. The annealing treatment of as-soldered Cu/Sn-57Bi-1Ag/Cu solder interconnects caused the obvious coarsening of Bi phases in the bulk solders and a slight reduction in the electric resistance of the solder interconnects. The coarsening of the Bi phases induced a decrease in the Bi/β-Sn phase boundaries and thus a decrease in the EM-induced atomic diffusion flux of Bi atoms during the subsequent current stressing, resulting in the segregation of a thinner Bi phase layer at the anode and a lower increase rate of electric resistance of the solder interconnects. The longer the annealing time, the higher the EM resistance of the solder interconnects. The reductions in both the effective diffusion coefficient of the Bi atoms and the electric resistivity of the bulk Sn-57Bi-1Ag solders induced by the annealing treatment were responsible for the higher EM resistance of low-temperature Sn-57Bi-1Ag solder interconnects. [ABSTRACT FROM AUTHOR]

To be able to carry out a high-quality analysis of the operation and design of elevator systems with a driving pulley, it is necessary to determine the size of the losses that occur in the drive mechanism and elevator guide rails. The paper defines an experimental procedure for determining the losses and the efficiency coefficient of elevator facilities depending on the relative load of the cabin in operational conditions. The experiment was carried out on a passenger elevator with a rated load of 320 kg and a lifting height of 28 m. An analysis of the resistance, i.e., the source of power losses in vertical lifting devices, was performed, the most significant of which occur and are especially pronounced in worm gear reducers and on the guiding system of the cabin and counterweight, where the type of guiding elements also has an influence. A particular problem is expressed due to the changing state of the contact surfaces (between the guide rails and the guide shoes) during exploitation and the eccentric loading of the cabin. Also, the paper analysed the obtained measurement results to determine the dependence of the efficiency coefficient of the facility concerning the relative load of the cabin. [ABSTRACT FROM AUTHOR]

The contact finger electrical connection structure is a crucial component of high voltage bushings, and its safety and reliability directly impact the operational stability of the bushing. To investigate electrical contact performance of the contact finger under eccentric conditions, a three‐dimensional electrical, thermal, and force multi‐physics coupling calculation model was established. Additionally, a test platform was constructed to measure electrical contact characteristics of the contact finger. The contact characteristics of the contact finger when the male head was axially deflected and radially offset compared to the female head were obtained. The research findings indicate when the male head deflects axially, the contact force changes of the contact finger blades on both sides are opposite. Moreover, as the axial deflection angle of the male head increases, the resistance of the electrical connection structure shows a rising‐slow decreasing‐fluctuating trend. The resistance is highest at 3°, with a resistance increase rate of 7.35%. Furthermore, the resistance of the electrical connection structure varies with the radial offset of the male head, following a power function. Contact failure occurs when the radial offset is 1.31 mm, and the resistance increase rate reaches 24.9% at a radial offset of 1.58 mm. [ABSTRACT FROM AUTHOR]

Particles regularly tribocharge in collisions. Here, we study how long charges can persist on such particles in the environment of a protoplanetary disc. We set up three complementary experiments to quantify discharge time-scales. We first directly measure the time dependency of charge on triboelectrically charged objects. For this aspect, we performed two long-time experiments under different environmental conditions. We find that the charge persists on the tribocharged bodies on time-scales between minutes and years. Discharge might be mediated by external ions or internally, by conduction. To constrain the latter, we also determined the specific electric resistance of dust samples as simulants for dust aggregates in protoplanetary discs. In this third experiment, we see an increase in resistivity at decreasing ambient pressure up to the limit of the instrument. These findings are consistent with the assumption that water on all relevant surfaces including dust grains within the pore space of aggregates is the main driver of discharge. Under disc conditions, the charge might persist for weeks to years. This leaves net-charged isolated grains in dense parts of the mid-plane of protoplanetary discs charged in between collisions. [ABSTRACT FROM AUTHOR]

The development of electric resistance is a key factor affecting the performance of conductive concrete, especially the electrical–thermal performance. In this work, the effects of different influencing factors (including the water-to-binder ratio, coarse aggregate content and carbon fiber (CF) content) on the electric resistance of conductive concrete were systematically investigated. At the same time, ohmic heating (OH) curing was applied to fabricate CF-reinforced conductive concrete (CFRCC) under a negative temperature environment at −20 °C. The effects of different factors on the electrothermal properties (curing temperature and conductive stability) of the samples were studied. The mechanical strengths of the CFRCC cured by different curing conditions were also tested, and the feasibility of OH curing for preparing CFRCC in a negative-temperature environment was verified at various electric powers. This work aims to give new insights into the effects of multiple factors on the performance of CFRCC for improved concrete construction in winter. [ABSTRACT FROM AUTHOR]

Naturally fermented dairy products are an important component of the human diet. They are a valuable source of nutrients as well as vitamins and minerals. Their importance as a source of probiotic bacterial strains should not be overlooked. A number of studies highlight the positive effects of species of the probiotic lactic acid bacteria on the intestinal microbiome and the overall homeostasis of the body, as well as a complementary treatment for some diseases. However, data on the effects on the intestinal epithelial cells of postmetabolites released by probiotic bacteria are incomplete. This is likely due to the fact that these effects are species- and strain-specific. In the present study, we investigated the effects of postmetabolites produced by a pre-selected candidate probiotic strain Limosilactobacillus fermentum on HT-29 intestinal epithelial cells. Our data showed a pronounced proliferative effect, evaluated by flow cytometry, quantification of the cell population and determination of the mitotic index. This was accompanied by the stabilization of the cell monolayer, measured by an increase in TEER (transepithelial electric resistance) and the reorganization of actin filaments. The data obtained are a clear indication of the positive effects that the products secreted by L. fermentum strain 53 have on intestinal epithelial cells. [ABSTRACT FROM AUTHOR]

This study analyzes the effect of the temperature coefficient of electric resistance on the thermal performance of a film heater for satellite applications. A heating element in the film heater was fabricated using silver paste and screen-printing technology. The temperature distributions of the film heater were numerically simulated on the basis of the heat transfer equation. The temperature coefficient of resistance was evaluated by measuring the film-heater temperature at various voltages using a forward-looking infrared (FLIR) camera. The results showed that the electric resistance linearly increased with a temperature variation. By considering the temperature coefficient of electric resistance, the error of numerical simulation decreased from 22.5% to 10%. The voltage required to reach the maximum allowable temperature at a given sink temperature was higher than the design voltage when the temperature coefficient was not considered. This indicated that greater power would be required to operate the film heater in real satellite applications. [ABSTRACT FROM AUTHOR]

Rich biological information in sweat provides great potential for health monitoring and management. However, due to the complexity of sweat, the development of environmentally friendly green electronic products is of great significance to the construction of ecological civilization. This study utilized a simple combination of polystyrene sulfonate sodium (PSS) and filter paper (FP) to prepare cellulose materials coated with conductive polymers, developing an electrochemical sensor based on the modified materials. The mechanical and electrochemical properties of the fabricated PSS/FP membrane were optimized by adjusting the feeding dosage of PSS. The realized PSS/FP composite containing 7% PSS displayed good conductivity (9.1 × 10−2 S/m), reducing electric resistance by 99.2% compared with the original FP membrane (6.7 × 10−4 S/m). The stable current of the membrane in simulated sweat under different pH environments is highly correlated with the pH values. Additionally, when the membrane is exposed to simulated sweat with varying ion concentrations, the current signal changes in real time with the concentration variations. The response time averages around 0.3 s. [ABSTRACT FROM AUTHOR]

The article focuses on analyzing changes in the chemical composition of steel samples after the cooling phase. A few distinct types of samples made of St3S steel were heated in an electric resistance furnace for 1 h. The temperature in the following minutes of the furnace work was programmed to reflect the standard fire curve defined in the Eurocode in the best possible way. The box-type electric furnace was used. There were three series of samples, and each of them was cooled down in diverse ways: (a) in the water, (b) in the polymer cooling medium AQUA-QUENCH® 320, and (c) in the furnace. After that, the chemical composition of diverse types of samples with various kinds of cooling was checked. This task was realized using a laser elementary analysis microscope with the EA-300 head. The investigation allowed the authors to draw the following conclusions: the electric furnace may be used to simulate an increase in temperature with fire duration according to standard fire curve only in the phase of fully developed fire situation; the EA-300 head for laser elementary analysis allows checking of the chemical composition of investigated elements very quickly (in a few seconds). [ABSTRACT FROM AUTHOR]

Recycling lithium-ion batteries provides sustainable raw materials. Crushing and separation are necessary for extracting metals, like lithium, from batteries. Crushing a battery carries a risk of fire or explosion. Fully discharging the battery is crucial for safe production. Discharging batteries in a salt solution is a simple and cost-effective large-scale process. However, it is important to note that there is a potential risk of corrosion and loss of battery elements when batteries are immersed in a salt solution. The purpose of this study is to investigate the effectiveness of two distinct methodologies at enhancing the voltage drop of a cylindrical battery when immersed in a salt solution while preventing corrosion. These techniques involve the application of iron and copper accelerators. A 20 wt.% salt water solution was chosen based on the research of several researchers. As the current flows through the metal parts, it encounters electrical resistance and forms an electric circuit with the electrolyte solution. This interaction converts electrical energy into various physical–electrical–electrochemical phenomena, leading to a decrease in battery voltage. Research revealed that the battery can be discharged up to 100% within 4 h without causing corrosion to its components. Another point to note is that if copper conductors are used, it is possible to decrease the battery voltage by around 90% within 8 h. The gap between the copper conductor and the battery had a direct impact on the battery's discharge rate. Reducing the distance significantly increased the discharge rate, as confirmed by experimental evidence. This discharge mechanism was thoroughly described in a schematic, and, to further explain the electrochemical reaction, the Pourbaix diagram was utilized for both the Fe-Na-Cl and Cu-Na-Cl systems. Moreover, our theoretical predictions were validated through a chemical and mineralogical analysis of the precipitates that formed in the solution. [ABSTRACT FROM AUTHOR]

The work was carried out as part of a project to improve the corrosion resistance of welded joints. The optimal selection of input parameters reduces the consumption of welded material as well as the negative impact on the environment. The samples were welded by electrical resistance welding, more precisely by cross-wire welding. Electric resistance welding is a process for welding with electricity in which of high electrical resistance is used to generate heat at the contact point of the welded parts. Steel wire S235 with a diameter of 4 and 3 mm was used. The article shows the creation of the model to predict the percentage of setdown and weld strength as a function of the input parameters, welding current and welding time. The first task was to create a Design of experiments in which the process parameters or the range of input parameters are determined. The Design of the experiments was created for both wire diameters. This covers the range of parameters with which a welded joint of wires can be realised. A statistical analysis of the process follows, where it was found that for 4 and 3 mm diameter wires the percentage setdown increases with increasing welding current and time. An increase in strength as a function of welding current and welding time is also observed, but the results overlap in most cases and the range of their values is greater than that of setdown. The appearance of the weld was analysed for each sample. The visual inspection revealed seven categories of welds, which were divided into two groups, i.e. good and poor welds. All results were listed in a table with the percentage of expectation for a particular category of weld appearance. Based on the analysis, a model for determining the welding result parameters depending on the specified input parameters was developed, which can be used in practise to support the management of the electric resistance welding process. [ABSTRACT FROM AUTHOR]

Within the context of reducing the environmental impact generated by the current generation, a constant challenge for the automotive industry is to produce vehicles with the lowest possible environmental impact. In this context, in order to reduce vehicle weight and, consequently, reduce fuel consumption and emissions of gases harmful to the environment, the automotive industries have been using advanced high-strength steels. These steels make it possible to reduce thickness without losing mechanical strength and, therefore, without compromising passenger safety. Among these steels, 22MnB5 steel stands out. Among the welding processes used to weld steel sheets, electrical resistance spot welding is the most widely used joining technique in the automotive industry. The main reasons for its wide application are that it is a process in which no material addition is required and it has a high processing speed and low processing costs. In this context, this study proposes a bibliometric and systematic review of electrical resistance spot welding of 22MnB5 steel. The main objective of this study was to identify current research trends and impacts, along with a comprehensive revision. The research was carried out using the Proknow-C method. A bibliographic portfolio of 50 articles was compiled. The bibliometric analysis revealed that articles related to this topic increased substantially between 2016 and 2023 compared to previous years. The systematic evaluation of the papers in the bibliographic portfolio made it possible to identify aspects such as the research problems addressed, the materials and methodologies used, the results evaluated, and the research gaps. It was found that most of the studies focused on the weldability and mechanical performance characteristics of similar two-plate joints with an average thickness of 1.5 mm and Al-Si coatings. Finally, this article provides a comprehensive overview of the research on electric resistance spot welding of 22MnB5 steel and can provide guidance for future studies to improve the process. [ABSTRACT FROM AUTHOR]

As one of the most attractive lead-free piezoelectric ceramics, K 0.5 Na 0.5 NbO 3 (KNN) has received widespread attention and by elemental doping or forming solid solution with other components, the electrical properties can be improved dramatically. Among which, BaZrO 3 (BZ) as a most promising solid solution for modification has been introduced in KNN to induce a phase transition and thus promote the electrical performance to further meet practical applications. However, the relationship between microscopic structural characteristics and macroscopic performance is still relatively vague and need to be clarified. Hence, in this work, the structural, elastic, and electronic properties of BZ-modified KNN were investigated using the first-principle calculations. The calculated results demonstrated that BZ entered the lattice of KNN spontaneously, strengthened the Nb–O octahedron distortion and optimized the elastic properties, which are all beneficial to improving the structural asymmetry and piezoelectric response. In addition, doping Ba resulted in the shift of Fermi surface toward the conduction band and thus decreased the band gap, while doping individual Zr increased the band gap. Under the coupling action of these two atoms, KNN-BZ illustrated more denser band structure and more wider band gap, which facilitated the promotion of electrical breakdown resistance and electric polarization of KNN. This study provides theoretical insights into improving the piezoelectricity of KNN. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) offers new possibilities in soft robotics as materials can easily be combined in multi-material designs. Proper sensing is essential for the soft actuators to interact with the surroundings successfully. By fabricating sensors through AM, sensors can be embedded directly into the components during manufacturing. This paper investigates NinjaTek Eels electrical resistance response to strain and the feasibility of using the material to create strain sensors. Strain sensors were 3D-printed out of NinjaTek Eel, a soft conductive TPU, and was tested during cyclic loading. A custom resistance–strain test rig was developed for measuring sensor behavior. The rig was calibrated for electric resistance, able to measure electric resistance as a function of strain. A parabolic response curve was observed during cyclic loading, which led to ambiguous readings. A 10-specimen validation test was conducted, evaluating the statistical variation for the first 100 loading cycles. The validation test showed that the sensor is capable of accurate and predictable readings during single load cases and cyclic loading, with the overall root mean square error being 66.9 Ω. Combining two sensors of different cross-sections gave promising results in terms of calibrating. By monitoring load cycles and strain rates, calibration can also be achieved by machine learning models by the microcontroller used to extract data. The presented work in this article explores the potential of using conductive TPUs as sensors embedded in products such as soft robotics, life monitoring of products with structural, and digital twins for live product to user feedback. [ABSTRACT FROM AUTHOR]

Magnetic tunnel junctions (MTJs) are the core elements of spintronic devices. Now, the mainstream writing operation of MTJs mainly relies on electric current with high energy dissipation, which can be greatly reduced if an electric field is used instead. In this regard, strain-mediated multiferroic heterostructure composed of MTJ and ferroelectrics are promising with the advantages of room temperature and magnetic field-free as already demonstrated by MTJ with in-plane magnetic anisotropy. However, there is no such report on the perpendicular MTJs (p-MTJs), which have been commercialized. Here, we investigate electric-field control of resistance state of MgO-based p-MTJs in multiferroic heterostructures. A remarkable and nonvolatile manipulation of resistance is demonstrated at room temperature without magnetic field assistance. Through various characterizations and micromagnetic simulation, the manipulation mechanism is uncovered. Our work provides an effective avenue for manipulating p-MTJ resistance by electric fields and is notable for high density and ultralow power spintronic devices. [ABSTRACT FROM AUTHOR]

The appearance, evolution, and proliferation of electric-vehicle motors have introduced new challenges for lubricants. The appearance of electric currents in the shafts of electric motors can dramatically change the original properties of lubricated contacts, leading to mechanism failure. Understanding and controlling this phenomenon can be advantageous for lubrication, but investigating the lubricants requires specific equipment and conditions. Therefore, in this study, we introduced a ball-on-plate reciprocating tribometer capable of applying electric voltage to the elements of the friction pair and measuring the electric contact resistance (ECR) as feedback. Mineral-based paraffin oil was used as a lubricant in this study. The coefficient of friction (COF), wear, surface morphology, and composition were analysed. It was found that high-speed ECR measurement could give valuable information regarding the lubrication conditions in reciprocating friction pairs. This study shows that even tiny currents flowing through the tribo contact can alter the lubricating conditions. Moreover, the polarity of the applied voltage is also of great importance. Applying negative voltage to the harder surface can significantly increase wear if the tribo-film is based on surface oxidation. [ABSTRACT FROM AUTHOR]

Polymer-derived SiAlCN ceramics as sensing materials are promising materials for wireless temperature sensors to achieve application in high-temperature harsh environments. However, limited understanding for the electric and dielectric properties of SiAlCN ceramics restricts the development of wireless sensors. Herein, the electrical and dielectric properties of polymer-derived SiAlCN ceramics pyrolyzed at different temperatures are investigated systemically. The results reveal that the electric resistance of the free-carbon phase and amorphous SiAlCN ceramic phase are comparable, however, the dielectric constant of the ceramic phase is much higher than that of the free-carbon phase. The maximum dielectric constant can reach up to 2.4E+5. Furthermore, the detailed mechanism analysis reveals that the SiAlCN ceramics with different pyrolysis temperatures all obey the same relaxation process, which is interfacial polarization and non-Debye relaxation. The deep understanding of the dielectric property of polymer-derived SiAlCN ceramics is very practical to design wireless sensors for potential applications in high-temperature and harsh environments. [ABSTRACT FROM AUTHOR]

The effects of water absorption on the electric resistivity and dielectric constant of polyimide (PI) and poly(ethylene terephthalate) (PET) were investigated, and the mechanism of deterioration in electrical insulation properties was discussed. The polyimides are poly(oxydianiline pyromellitimide) (PMDA–ODA) and poly(para-phenylene diamine biphenyltetracarboxydiimide) (BPDA–PDA). These polymer films were immersed in pure water for various immersion times at room temperature, and the water absorption ratio was evaluated. The electric resistance for these films was measured at room temperature using a high-resistance meter, and the dielectric constant at room temperature was measured using an LCR meter in a frequency range of 200 kHz to 2 MHz. The absorption ratios at equilibrium absorption for PMDA–ODA, BPDA–PDA, and PET were 2.7, 2.5, and 0.5%, respectively. The critical volume fraction of the percolation threshold of electric conductivity due to water absorption was 0.034 for both PMDA–ODA and BPDA–PDA. On the other hand, PET did not show a significant decrease in the resistivity. For both PIs and PET, the dielectric constant observed could be explained by a series model of the respective capacitances of pure water and polymer. Actually, the resistivity of samples cut from the edges of the film after water absorption was almost the same value as that in the dry state. These results suggest that the absorbed water molecules are not uniformly dispersed in the film but are localized at the edges of the film even after the absorption equilibrium has been reached. [ABSTRACT FROM AUTHOR]

Iron oxide nanomaterials are promising candidates for various electrochemical applications. However, under operating conditions high electric resistance is still limiting performance and lifetime. By incorporating the electronically conductive carbon into a nanohybrid, performance may be increased and degeneration due to delamination may be prevented, eliminating major drawbacks. For future applications, performance is an important key, but also cost-effective manufacturing suitable for scale-up must be developed. A possible approach that shows good potential for up-scale is magnetron sputtering. In this study, a systematic investigation of iron oxides produced by RF magnetron sputtering was carried out, with a focus on establishing correlations between process parameters and resulting structural properties. It was observed that increasing the process pressure was favourable with regard to porosity. Over the entire pressure range investigated, the product consisted of low-crystalline Fe3O4, as well as Fe2O3 as a minor phase. During sputtering, a high degree of graphitisation of carbon was achieved, allowing for sufficient electronic conductivity. By means of a new alternating magnetron sputtering process, highly homogeneous salt-and-pepper-type arrangements of both nanodomains, iron oxide and carbon were achieved. This nano-containment of the redox-active species in a highly conductive carbon domain improves the material's overall conductivity, while simultaneously increasing the electrochemical stability by 44%, as confirmed by cyclic voltammetry. [ABSTRACT FROM AUTHOR]

In this work, bilayer nanocoatings were designed and constructed on high-performance aromatic polysulfonamide (PSA) fibers for robust electric conduction and electromagnetic interference (EMI) shielding. More specifically, PSA fibers were first endowed with necessary electric conductivity via electroless nickel (Ni) or nickel alloy (Ni-P-B) plating. Afterward, silver electroplating was carried out to further improve the performance of the composite. The morphology, microstructure, environmental stability, mechanical properties, and EMI shielding performance of the proposed cladded fibers were thoroughly investigated to examine the effects of electrodeposition on both amorphous Ni-P-B and crystalline Ni substrates. The acquired results demonstrated that both PSA@Ni@Ag and PSA@Ni-P-B@Ag composite fibers had high environment stability, good tensile strength, low electric resistance, and outstanding EMI shielding efficiency. This indicates that they can have wide application prospects in aviation, aerospace, telecommunications, and military industries. Furthermore, the PSA@Ni-P-B@Ag fiber configuration seemed more reasonable because it exhibited smoother and denser silver surfaces as well as stronger interfacial binding, leading to lower resistance (185 mΩ cm−1) and better shielding efficiency (82.48 dB in the X-band). [ABSTRACT FROM AUTHOR]

Tungsten/tungsten nitride bilayer with amorphous structure was deposited on the silicon / silicon oxide substrate by high vacuum thermal evaporation method. To investigate the thermal stability of this bilayer as a diffusion barrier layer, the Cu/W/WN/SiO2/Si multilayer was heated at different temperatures and the results were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM) and four-point probe (FPP) methods. According to the XRD results, formation of the cupper silicide at 800° C indicates diffusion of copper from the W/WN bilayer in the Si. The formation of a Cu3Si with insulation phase leads to a sudden increase in electrical resistance (212 Ω/cm2) and will disrupt the performance of the W/WN barrier layer as a diffusion barrier. The diffusion of copper into silicon is often through undesirable grain boundaries that occur during the heating treatment of the W/WN bilayer by changing its phase from amorphous to polycrystalline and shown in X-ray diffraction results. At high temperatures, the electron microscope image has shown fracture, cracking and flaking of the surface of the copper layer, which is caused by thermal stress between the penetration barrier/copper surfaces or the volume of the layers. [ABSTRACT FROM AUTHOR]

With the expansion of the applications of sensors, requirements such as flexibility, visual transparency, and self-powering have become critical. In this work, firstly we have adopted photoetch and hierarchical (micro-nano) manufacturing techniques to fabricate a micro-scale copper grid on polyethylene terephthalate (PET). This material (Cu grid @PET) exhibits high transmittance (89% at 550 nm, only 2.7% lower than PET substrate) and low electric resistance (6.7 Ω sq−1) compared with other reports. Then, the as-fabricated Cu grid @PET composite electrode, poly-dimethylsiloxane (PDMS), and polymethyl methacrylate (PMMA) were utilized to fabricate a sandwich-like structured transparent self-powered sensor (TSPFS) with high optical transmittance of 85.5-87.5% (450 ~ 620 nm). A complete novel control method combining with sensor's electrical signal test was implemented by Dynamic Mechanical Analyzer (DMA), verifying the simulation response to space of COMSOL. Voltage signals could be also observed when the sensor was touched by fingers without receiving electric energy from external sources. Finally, the paper shows a kind of smart goggles made of the produced transparent device, exhibiting heating, antifogging, and sensing functions. [ABSTRACT FROM AUTHOR]

Carbon nanotubes (CNTs) due to their outstanding features, such as unique electronic properties and large specific surface areas, have been intensively studied as nanoscale fillers to improve the permittivity of polymer dielectrics. However, due to the unfavourable formation of conductive channels, these CNTs-derived nanocomposites usually suffer from high dielectric loss and low breakdown strength, therefore greatly restricting their practical applications. In this work, we modified pristine multiwalled carbon nanotubes (MWCNTs) by chemical oxidation to prepare partially unzipped carbon nanotubes (PUCNTs), which not only retained excellent electrical properties but also enhanced interfacial interactions with polymers. The obtained PUCNTs/poly(vinylidene fluoride) (PVDF) nanocomposites exhibit higher permittivity and lower dielectric loss compared to raw MWCNTs added. To further alleviate the detrimental influence of conductive channels, we have designed a new class of hybrid composed of PUCNTs-decorated CaCu3Ti4O12 nanoparticles (PUCNTs-CCTO) and their PVDF-based nanocomposites. At 1 kHz, the PUCNTs-CCTO/PVDF nanocomposite filled the ternary nanocomposites also possess strong resistance to electric field failure and achieve significantly enhanced energy storage capability. With 3 vol% PUCNTs and 30 vol% CCTO, the breakdown strength of the nanocomposite can still be maintained at 125 kV mm−1 and the theoretical maximum energy density reaches to 15.5 J cm−3, which is nearly 3 times compared to neat PVDF (5.1 J cm−3). These merits of the PUCNTs-CCTO/PVDF nanocomposites suggest that the strategy proposed herein is a promising avenue for the development of dielectric materials with high energy storage capacity. [ABSTRACT FROM AUTHOR]

The present study approaches comparative research on the thermal transfer between the components of the plasticizing part of the PLA and ABS type material respectively. It can be observed that besides the fact that the temperature difference between the heating part generated with an electric resistance placed in the heated block and the nozzle is not very large, the thermal transfer is relatively linear with small temperature losses. [ABSTRACT FROM AUTHOR]

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Improving the filtration efficiency of air filter materials is an ongoing research goal. This study conducted in-depth research on a new reduced graphene oxide air filter material, and the differences in its performance and conductivity durability before and after eliminating static electricity were tested and analyzed. The results showed that the filtration efficiency of the reduced graphene oxide air filter material significantly decreased after eliminating static electricity. The maximum decrease in filtration efficiency was observed at a filtration velocity of 0.8 m/s, with PM10 > PM1.0 > PM2.5. In this case, the filtration efficiency decreased by 11.8%, 7.98%, and 7.17%, respectively. The maximum difference in filtration efficiency of 0.29 μm particulates was about 12.7%. Eliminating static electricity slightly increased the resistance (2.5~15.5 Pa). In addition, the new reduced graphene oxide air filter material exhibited good conductivity and stability after continuous testing. This study provides data support for the application of subsequent electrification sterilization, reference values for multi-angle applications, and the development of new composite air filter materials. [ABSTRACT FROM AUTHOR]

Scavenging energy from aeroelastic vibrations was considered for a self-powered hybrid passive-active stall control system intended to improve the aerodynamic performance of fixed-wing micro aerial vehicles without exhausting available batteries. It was found that the passive component of the system generates intense streamwise vortices, which give rise to vortex-induced vibrations. Measured frequency response functions indicated accelerations in a wing prototype up to 0.1 g at relatively low frequencies, when it was operated at simulated flight conditions in a wind tunnel. Aiming to use this resource for additional power, a piezoelectric energy harvesting device was installed inside the wing and tuned for resonant response. Two electromechanical modeling approaches for the piezoelectric harvester were investigated, namely, an analytical model and finite elements simulations. A comparison with experimental results has shown that the latter approach is better equipped to deal with advanced designs, yielding accurate predictions in the present study. Extracted power and generated voltage were quantified as a function of the electric loading resistance. The reported data demonstrated that the proof of concept was achieved, so that a lightweight, low-consumption actuator for the active component of the stall control system can be powered by the energy of structural vibrations. [ABSTRACT FROM AUTHOR]

The emerging high-entropy oxides (HEOs) have been considered promising candidates in numerous applications due to their unique properties. Yet the dielectric properties of HEOs at high pressure remain to be disclosed. In this work, the dielectric properties of (FeCoCrMnZn) 3 O 4 at high pressures up to ∼20 GPa were systematically investigated. Combined with in-situ Raman, XRD, and impedance measurements, it is revealed that high-pressure exhibits a significant impact on the dielectric properties, even without the observed phase transition. The electric resistance, which is dominantly contributed by grain resistance, decreases exponentially with the increase of pressure. On the other hand, the relative permittivity decreases linearly with increasing pressure. In addition, the dielectric relaxation behavior of (FeCoCrMnZn) 3 O 4 at high pressure is revealed. Our results provide the experimental basis for the high-pressure effect on the dielectric properties of (FeCoCrMnZn) 3 O 4 and potential guidance for the design strategy of HEOs under extreme conditions. [ABSTRACT FROM AUTHOR]

Evaluations of nonintrusive load monitoring (NILM) algorithms and technologies have mostly occurred in constrained, artificial environments. However, few field evaluations of NILM products have taken place in actual buildings under normal operating conditions. This paper describes a field evaluation of a state-of-the-art NILM product, tested in eight homes. The match rate metric—a technique recommended by a technical advisory group—was used to measure the NILM's success in identifying specific loads and the accuracy of the energy consumption estimates. A performance assessment protocol was also developed to address common issues with NILM mislabeling and ground-truth comparisons that have not been sufficiently addressed in past evaluations. The NILM product's estimates were compared to the submetered consumption of eight major appliances. Overall, the product had good performance in disaggregating the energy consumption of the electric water heaters, which included both electric resistance and heat-pump water heaters, but only a fair accuracy with refrigerators, dryers, and air conditioners. The performance was poor for cooking equipment, furnace fans, clothes washers, and dishwashers. Moreover, the product was often unable to detect major loads in homes. Typically, two or more appliances were not detected in a home. At least two dryers, furnace fans, and air conditioners went undetected across the eight homes. On the other hand, the dishwasher was detected in all homes where available or monitored. The key findings were qualitatively compared to those of past field evaluations. Potential areas for improvement in NILM product performance were determined along with areas where complementary technologies may be able to aid in load-disaggregation applications. [ABSTRACT FROM AUTHOR]

The paper focuses on transport properties of double perovskite Sr2FeMoO6−δ, which were studied experimentally and using First principles calculations. The strontium ferromolybdate specimens were prepared using citrate-gel method followed by compacting and thermal treatment at different regimes. The Hall effect was calculated using Quantum Espresso and Wannier90 software packages. The study conformed high sensitivity of Sr2FeMoO6 to the processing parameters such as pressure and temperature of powder compacting as well as the temperature and duration of the subsequent annealing in Ar/O2 atmosphere. The optimal regime of compacting to avoid cracking involved pressing under 4 GPa at T = 800 K. Further heat treatment of the compacted specimens in Ar/O2 atmosphere has shown that three types of electric conductivity, namely metallic, semiconducting and mixed one can be realized in the Sr2FeMoO6 specimens. The highest magnitude of magnetoresistance was found in the semiconducting specimen (about 44%), while the specimen of metallic type demonstrated magnetoresistance of about 21%. The elevated values of magnetoresistance in the semiconducting specimen were achieved due to conduction mechanism related to tunneling through intergrain dielectric layers formed by secondary SrMoO4 phase. The Hall effect was computed by constructing the Hamiltonian in the maximally-localized Wannier functions basis. Calculations of the Berry curvature, which is the origin of the high intrinsic Hall effect showed that its highest magnitudes concentrate near avoided band crossings gapped out due to spin-orbit coupling. The Hall conductivity calculated by integrating the Berry curvature over all occupied bands was found to be ~22 S/cm. [ABSTRACT FROM AUTHOR]

Fluorspar (CaF2) is the most used flux in hot metal desulfurizing mixtures. However, its use can cause refractory wear and environmental contamination, prompting research efforts to develop alternative desulfurizing mixtures. This study aims to investigate the replacement desulfurizing mixtures containing fluorspar by other desulfurizing mixtures containing a new flux developed without fluorspar named MIX. The influence of varying the mass of these desulfurizing mixtures, temperature, and stirring of the system on the efficiency of hot metal desulfurization was also studied. The desulfurization experiments were carried out in an electric resistance furnace, at a temperature of 1370°C. Hot metal samples were taken to measure the change in sulfur content in the experiments. FactSage 8.0 software, was used to determine the phases present in the desulfurizing mixtures, and these phases were correlated with the hot metal desulfurization efficiency. The efficiency of the desulfurizing mixtures was also correlated with the Desulfurization Factor. The results showed that desulfurizing mixtures containing fluorspar are the most efficient mixtures. However, fluorspar-free desulfurizing mixtures containing MIX can achieve similar efficiencies with increases in mass, temperature, and system stirring. The results also showed that the most efficient desulfurizing mixtures are those with higher percentages of solid CaO and lower percentages of the solid phases 3CaO.SiO2 and CaS and, consequently, a higher Desulfurization Factor. [ABSTRACT FROM AUTHOR]

Thermoelectric phenomena, such as the Anomalous Nernst and Longitudinal Spin Seebeck Effects, are promising for sensor applications in the area of renewable energy. In the case of flexible electronic materials, the request is even larger because they can be integrated into devices having complex shape surfaces. Here, we reveal that Pt promotes an enhancement of the thermoelectric response in Co-rich ribbon/Pt heterostructures due to the spin-to-charge conversion. Moreover, we demonstrated that the employment of the thermopiles configuration in this system increases the induced thermoelectric current, a fact related to the considerable decrease in the electric resistance of the system. By comparing present findings with the literature, we were able to design a flexible thermopile based on LSSE without the lithography process. Additionally, the thermoelectric voltage found in the studied flexible heterostructures is comparable to the ones verified for rigid systems. [ABSTRACT FROM AUTHOR]

Chitosan, a polyaminosaccharide with high medical and cosmetic potential, can be combined with the beneficial properties of glycolic acid to form a gel that not only moisturizes the skin, but also has a regenerative effect. Its involvement in the activation of biochemical processes may be associated with the activity of skin ion channels. Therefore, the aim of the research was to evaluate the immediate (15 s) and long-term (24 h) effect of chitosan–glycolic acid gel (CGG) on the transepithelial electric potential and the transepithelial electric resistance (R) of skin specimens tested in vitro. Stimulation during immediate and prolonged application of CGG to skin specimens resulted in a significant decrease in the measured minimal transepithelial electric potential (PDmin). The absence of any change in the R after the CGG application indicates that it does not affect the skin transmission, or cause distortion, microdamage or changes in ion permeability. However, the reduction in potential may be due to the increased transport of chloride ions, and thus water, from outside the cell into the cell interior. Increased secretion of chloride ions is achieved by stimulating the action of the CFTR (cystic fibrosis transmembrane conductance). It can be assumed that chitosan gently stimulates the secretion of chlorides, while maintaining a tendency to reduce the transport of sodium ions, without causing deformation or tissue damage. [ABSTRACT FROM AUTHOR]

The main cause for concern is power quality (PQ) problems, specifically voltage disturbances, fluctuation, sag, harmonics, and swell in the power distribution system. To correct these voltage disturbances in the electrical power distribution system, an efficient device called a dynamic voltage restorer (DVR) is integrated between the source and the load. In this study, DVR is integrated with the source to protect the sensitive load from voltage disturbances caused by the source side under non-linear load conditions. In addition, a unique Z-type source inverter (ZSI) is introduced to improve the restoration of the voltage property of DVR. This ZSI ensures that the direct current (DC) link used for the compensation process maintains a constant DC voltage. By adjusting the gain parameters of the propo rtion al-in tegra l-der ivati ve (PID) controller and accounting for voltage problems such as sag, fluctuation, swell, and interruption in the load side, the hybrid Harris hawks optimization (HHO) and black widow optimization (BWO) are also utilized to regulate the Z-source DVR (Z-DVR). The 2020Ra version of MATLAB/Simulink is used to implement this proposed work and analyze the outcomes. HHO-BWO is also compared to earlier works like BWO-PID, HHO-PID, genetic algorithm-PID, and mm-sized resistance-typed sensor film controller to demonstrate its superiority in terms of total harmonic distribution and problem-solving. [ABSTRACT FROM AUTHOR]

Electric conductivity in metal-organic frameworks (MOFs) follows either a band-like or a redox-hopping charge transport mechanism. While conductivity by the band-like mechanism is theoretically and experimentally well established, the field has struggled to experimentally demonstrate redox conductivity that is promoted by the electron hopping mechanism. Such redox conductivity is predicted to maximize at the mid-point potential of the redox-active units in the MOF, and decline rapidly when deviating from this situation. Herein, we present direct experimental evidence for redox conductivity in fluorine-doped tin oxide surface-grown thin films of Zn(pyrazol-NDI) (pyrazol-NDI = 1,4-bis[(3,5-dimethyl)-pyrazol-4-yl]naphthalenediimide). Following Nernstian behavior, the proportion of reduced and oxidized NDI linkers can be adjusted by the applied potential. Through a series of conductivity measurements, it is demonstrated that the MOF exhibits minimal electric resistance at the mid-point potentials of the NDI linker, and conductivity is enhanced by more than 10000-fold compared to that of either the neutral or completely reduced films. The generality of redox conductivity is demonstrated in MOFs with different linkers and secondary building units, and its implication for applications that require switching between insulating and semiconducting regimes is discussed. MOFs that transport electrons by a hopping mechanism are redox conductors. Here authors demonstrate a diagnostic bell-shaped conductivity curve that is centred around the formal potential of the redox active unit in a variety of MOFs. [ABSTRACT FROM AUTHOR]

The fabrication of low-electrical-percolation-threshold polymer composites aims to reduce the weight fraction of the conductive nanomaterial necessary to achieve a given level of electrical resistivity of the composite. The present work aimed at preparing composites based on multiwalled carbon nanotubes (MWCNTs) and magnetite particles in a polyurethane (PU) matrix to study the effect on the electrical resistance of electrodes produced under magnetic fields. Composites with 1 wt.% of MWCNT, 1 wt.% of magnetite and combinations of both were prepared and analysed. The hybrid composites combined MWCNTs and magnetite at the weight ratios of 1:1; 1:1/6; 1:1/12; and 1:1/24. The results showed that MWCNTs were responsible for the electrical conductivity of the composites since the composites with 1 wt.% magnetite were non-conductive. Combining magnetite particles with MWCNTs reduces the electrical resistance of the composite. SQUID analysis showed that MWCNTs simultaneously exhibit ferromagnetism and diamagnetism, ferromagnetism being dominant at lower magnetic fields and diamagnetism being dominant at higher fields. Conversely, magnetite particles present a ferromagnetic response much stronger than MWCNTs. Finally, optical microscopy (OM) and X-ray micro computed tomography (micro CT) identified the interaction between particles and their location inside the composite. In conclusion, the combination of magnetite and MWCNTs in a polymer composite allows for the control of the location of these particles using an external magnetic field, decreasing the electrical resistance of the electrodes produced. By adding 1 wt.% of magnetite to 1 wt.% of MWCNT (1:1), the electric resistance of the composites decreased from 9 × 104 to 5 × 103 Ω. This approach significantly improved the reproducibility of the electrode's fabrication process, enabling the development of a triboelectric sensor using a polyurethane (PU) composite and silicone rubber (SR). Finally, the method's bearing was demonstrated by developing an automated robotic soft grip with tendon-driven actuation controlled by the triboelectric sensor. The results indicate that magnetic patterning is a versatile and low-cost approach to manufacturing sensors for soft robotics. [ABSTRACT FROM AUTHOR]

Bushings made of platinum-rhodium alloys are a key component in glass fibre production. While bushings have grown in size and functionality since their introduction in the early 20th century, manufacturing constraints still limit their full potential. Both in terms of design and quality, traditional manufacturing methods such as milling, drilling and welding limit the potential of precious metal bushings. The technical feasibility of the use of additive manufacturing for the production of bushings is greatly dependent on the material properties. For the purpose of this work, an additively manufactured alloy consisting of 90 wt% platinum and 10 wt% rhodium (PtRh10) is investigated with regard to density, electrical resistivity, creep performance and the contact angle of E-glass on the PtRh10 samples. [ABSTRACT FROM AUTHOR]

A Tuk-tuk, also known as a motorized tricycle, is a three-wheeled vehicle with wheels symmetrically arranged in the longitudinal driving direction. Compared to four-wheeled vehicles, tuk-tuks have less stability. Classical Tuk-tuks typically have a metal occupant compartment without doors, resulting in direct contact between occupants and the metal structure. In tropical countries with heavy rainfall, flooded roads are common. This study proposes technical requirements specific to electric Tuk-tuks, which are gaining popularity in Thailand. Experimental tests focused on braking performance, rollover stability, and electric safety prevention. The tests addressed four aspects: brake performance, parking capability, rollover stability, and electric isolation resistance during floods. These tests help manufacturers meet Thai safety standards. Results emphasize the importance of adhering to Tuk-tuk standards for vehicle performance and electric safety. [ABSTRACT FROM AUTHOR]

Elastic strain sensor nanocomposites are emerging materials of high scientific and commercial interest. This study analyzes the major factors influencing the electrical behavior of elastic strain sensor nanocomposites. The sensor mechanisms were described for nanocomposites with conductive nanofillers, either dispersed inside the polymer matrix or coated onto the polymer surface. The purely geometrical contributions to the change in resistance were also assessed. The theoretical predictions indicated that maximum Gauge values are achieved for mixture composites with filler fractions slightly above the electrical percolation threshold, especially for nanocomposites with a very rapid conductivity increase around the threshold. PDMS/CB and PDMS/CNT mixture nanocomposites with 0–5.5 vol.% fillers were therefore manufactured and analyzed with resistivity measurements. In agreement with the predictions, the PDMS/CB with 2.0 vol.% CB gave very high Gauge values of around 20,000. The findings in this study will thus facilitate the development of highly optimized conductive polymer composites for strain sensor applications. [ABSTRACT FROM AUTHOR]

Composite structures are sensitive to impact damage in practical engineering. Electric resistance change method (ERCM) is an ideal technique for damage monitoring of composite structures. Due to the anisotropy of fiber-resin matrix composites, impact location monitoring is difficult, and research on impact location of fiber composite laminates (FRPs) is limited. A preparation method of MXene/CNT/CuNps thin film sensor is proposed. According to the modeling simulation and theoretical calculation, the resistance change characteristics of the thin film sensor are obtained, the relationship between the impact distance and the resistance change is established, and the sensor array is designed. A three-point localization algorithm and a weight function compensation localization algorithm are proposed, which can improve the imaging accuracy of the impact position. The impact point location was observed and analyzed using ultrasonic C-scan technology. The results show that the weight function compensation positioning algorithm can accurately locate the impact of the composite structure, and the error in the X direction is 7.1%, the error in the Y direction is 0.03%, which verifies the effectiveness of the method. [ABSTRACT FROM AUTHOR]

MnO2 nanowires/polyaniline composite (MnO2NW/PANI) was prepared by combining one-dimensional MnO2 nanowires (MnO2NW) with conductive polymer PANI surface coating. The MnO2NW were synthesized via a one-pot facile hydrothermal method. The composite MnO2NW/PANI was then prepared by in situ polymerization of aniline monomer on the surface of MnO2NW. The MnO2NW/PANI was able to serve as electroactive material and demonstrated a specific capacitance of 306.7 F/g recorded at a current density is 0.5 A/g, which is 28.4% higher than that of pristine MnO2 (only 238.9 F/g). The reduced electric resistance within MnO2NW/PANI interconnection networks and the good synergistic effect between MnO2NW and PANI for fast ion/charge transfer supports the enhanced capacitance of the composite. In addition, the MnO2NW/PANI composite electrode shows stable cycle performance, with capacity retention of 88.7% after 5000 repeated cycles test at a high current density of 5 A/g. The constructed nanocomposites have great potential in the further development of high-performance electrochemical electrode materials for energy storage application. [ABSTRACT FROM AUTHOR]

This research investigated an alternate method for establishing the complex coefficients used in an electric vehicle's mathematical energy consumption model. While other methods for creating electric vehicle energy models exist, it would be beneficial to have a rapid and inexpensive technique that remains accurate. Producing a mathematical energy model for such a vehicle has the challenge of determining its aerodynamic drag and rolling resistance coefficients. Currently and most often, expensive and tedious (time-consuming) methods are used to find these coefficients. Computational fluid dynamics (CFD), wind tunnel testing, and extensive mathematics make this objective challenging. For this work, a solar-powered electric vehicle provided the source data to derive its coefficients cost-effectively and efficiently. Data were collected during a road test of the solar electric vehicle from South Africa to Namibia stretching over 2000 km, in which all required energy variables were recorded. The collected data were used in an optimisation routine to establish the two coefficients by minimising the actual and modelled energy consumption error and controlling the driving speed. The outcome of the optimisation routine produced accurate coefficients with a final error value of less than 5% when applied to a validation data set not used during optimisation. With minor modifications, this method may be integrated into any electric vehicle computer system to autonomously identify its two hard-to-find coefficients while driving, which can be used to provide an accurate and realistic driving range estimation to the driver. [ABSTRACT FROM AUTHOR]

This paper presents an economic assessment of three drying systems (DS) with different configurations: diesel-powered (DDS), grid-powered (GDS), and photovoltaic-powered (PVDS). The third configuration, PVDS, presents important technological innovations regarding the electric configuration (stand-alone PV, without batteries or grid support) and the heat pump technology used (optimized for drying the recirculated air, which permits a reduction in the electricity consumption by more than 45% if compared to a diesel air-heater or an electric resistance). The profitability of the investment required for the installation of the three systems is proven by calculating the profitability index (PI), the internal rate of return (IRR), the payback period (PBP), and the levelized cost of energy (LCOE). All the indicators show good profitabilities for the three technologies (the PI values range from 6.78 to 10.11, the IRR values range from 24% to 37%, and the PBPs are between 3 and 4 years), but the PVDS clearly offers important economic advantages: its PI and IRR are more than 40% higher, the PBP is 25% shorter, and the LCOE is between 40 and 47% lower than for the two other systems. The results of this analysis correspond to a particular base case but are obviously sensitive to geopolitical and economic changes: the ultimate strength of the PVDS configuration is its resilience against a possible rise in electricity and diesel prices, reducing the uncertainty for investors and policymakers. [ABSTRACT FROM AUTHOR]

A photoelectrode for hydrogen evolution reaction (HER) is proposed, which is based on p-type silicon (p-Si) passivated with an ultrathin (10 nm) alumina (Al2O3) layer and modified with microformations of a nickel catalyst. The Al2O3 layer was formed using atomic layer deposition (ALD), while the nickel was deposited photoelectrochemically. The alumina film improved the electronic properties of the substrate and, at the same time, protected the surface from corrosion and enabled the deposition of nickel microformations. The Ni catalyst increased the HER rate up to one order of magnitude, which was comparable with the rate measured on a hydrogen-terminated electrode. Properties of the alumina film on silicon were comprehensively studied. Grazing incidence X-ray diffraction (GI-XRD) identified the amorphous structure of the ALD oxide layer. Optical profilometry and spectroscopic ellipsometry (SE) showed stability of the film in an acid electrolyte. Resistivity measurements showed that annealing of the film increases its electric resistance by four times. [ABSTRACT FROM AUTHOR]

Impedance spectroscopy is widely used in operando studies of solid‐state batteries for characterizing charge transport and correlating it with structural features. A typical impedance spectrum reveals, in addition to transport signals of the solid electrolyte, one or more contributions due to processes taking place at the electrode interfaces. The focus of this study is on reversible (parent) metal anodes and a 3D electric network model is used to analyze the variation of their impedance as a function of pressure, temperature, or aging during cycling. This provides a recipe for experimentalists on how to identify impedance contributions arising from different interface effects, such as, charge transfer, dynamic current constriction, and solid electrolyte interphase formation. Rules are derived for assigning the different interface signals or identifying the dominant contribution in case of similar frequency‐dependence and a standard procedure for analysis is proposed. The suggested procedure is applied to experimental data of half cells where lithium metal is in contact with garnet‐type Li6.25Al0.25La3Zr2O12. This case study yields unambiguously that geometric current constriction due to morphological instabilities at the metal anode interface during cycling is the rate‐limiting step for this type of metal anode, rather than the frequently assumed polarization resistance of the electric charge transfer migration process. [ABSTRACT FROM AUTHOR]

This paper deals with the laser cleaning of 34CrMo4 steel pipes to be adopted before the electrical upsetting process. The cleaning aims to decrease the pipes' roughness and the coupled electrical resistance with copper inserts to achieve lower wear and obtain an overall better electrical contact between the pipe and the copper inserts. Compared to a traditional process (shot blasting), the results showed that the laser cleaning treatment leads to a lower pipe roughness and a lowered wear of the copper inserts. The first experimental tests were conducted by using a 30-W Q-switched Yb:YAG fibre laser with different cleaning parameters such as scan speed, pulse frequency, and hatch distance to identify a workability range. Successively, a three-level full factorial plan was developed, and results were analysed through the analysis of variance (ANOVA) to understand which parameters were significant during the cleaning process. Also, the cleaned samples were compared to shot-blasted ones to evaluate the percentage improvements in terms of surface roughness, wear resistance, and coupled electrical resistance. In the third phase, a pre-industrialisation analysis was performed by adopting higher laser power sources (50–100 W) to reduce the cleaning time and define a possible industrial setup. It was found that with the laser cleaning treatment the surface quality increases (about 10 times lower Ra and Rz compared to shot blasting), with a decrease of the wear of about 22%. Moreover, the laser cleaning treatment improves the electric contact resistance and reduces the initial variability compared to the as-rolled sample. [ABSTRACT FROM AUTHOR]

The application of lab-on-a-chip technologies in in vitro cell culturing swiftly resulted in improved models of human organs compared to static culture insert-based ones. These chip devices provide controlled cell culture environments to mimic physiological functions and properties. Models of the blood-brain barrier (BBB) especially profited from this advanced technological approach. The BBB represents the tightest endothelial barrier within the vasculature with high electric resistance and low passive permeability, providing a controlled interface between the circulation and the brain. The multi-cell type dynamic BBB-on-chip models are in demand in several fields as alternatives to expensive animal studies or static culture inserts methods. Their combination with integrated biosensors provides real-time and noninvasive monitoring of the integrity of the BBB and of the presence and concentration of agents contributing to the physiological and metabolic functions and pathologies. In this review, we describe built-in sensors to characterize BBB models via quasi-direct current and electrical impedance measurements, as well as the different types of biosensors for the detection of metabolites, drugs, or toxic agents. We also give an outlook on the future of the field, with potential combinations of existing methods and possible improvements of current techniques. [ABSTRACT FROM AUTHOR]

One-dimensional nanomaterials have drawn attention as an alternative electrode material for stretchable electronics. In particular, silver nanowires (Ag NWs) have been studied as stretchable electrodes for strain sensors, 3D electronics, and freeform-shaped electronic circuits. In this study, Ag NWs ink was printed on the pre-stretched silicone rubber film up to 40% in length using a drop-on-demand dispenser. After printing, silicone rubber film was released and stretched up to 20% as a cyclic test with 10-time repetition, and the ratios of the resistance of the stretched state to that of the released state (Rstretched/Rreleased) were measured at each cycle. For Ag NWs electrode printed on the pre-stretched silicone rubber at 30%, Rstretched/Rreleased at 10% and 20% strain was 1.05, and 1.57, respectively, which is significantly less than about 7 for Ag NWs at the 10% strain without pre-stretched substrate. In the case of 10% strain on the 30% pre-stretched substrate, the substrate is stretched and the contact points with Ag NWs were not changed much as the silicone rubber film stretched, which meant that Ag NWs may slide between other Ag NWs. Ag NWs electrode on the 40% pre-stretched substrate was stretched, strain was concentrated on the Ag NWs electrode and failure of electrode occurred, because cracks occurred at the surface of silicone rubber film when it was pre-stretched to 40%. We confirmed that printed Ag NWs on the pre-stretched film showed more contact points and less electric resistance compared to printed Ag NWs on the film without pre-stretching. [ABSTRACT FROM AUTHOR]

This paper presents a study of the resistive behavior of a Shape Memory Alloy spring, with a focus on the application of electrical resistance feedback in control systems. Artificial Neural Networks of different topologies were designed to learn the relation between spring electrical resistance and the force exerted. The feedback between layers in Neural Networks is demonstrated to be a key parameter in learning the non-linear and hysteretic behavior of Shape Memory Alloys. Experiments with closed-loop systems showed that shape memory alloy springs generated forces that converged satisfactorily to the desired reference values. The scientific contribution of this work is the use of electrical resistance variation as feedback for controlling the spring force, eliminating the use of an external force sensor. Neural networks were used for both, the sensing process and the system control; in that way the nonlinear and hysterical behavior of the shape memory alloy actuator was well considered. [ABSTRACT FROM AUTHOR]