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The dynamics of spin and charge-ordered phases in La1.67Sr0.33NiO4 single crystal have been investigated using high-frequency dielectric spectroscopy. The measurements were carried out in frequencies between 0.156 and 316 MHz and temperatures from 50 to 320 K. The intrinsic part of the response by excluding the Maxwell–Wagner relaxation region is obtained below TSDW ∼ 120 K. The intrinsic frequency-dependent real dielectric constant ɛ′ and conductivity σ′ can be well described in terms of the constant phase element revealing a complex charge-hopping process. Our results are in agreement with the spin-density-wave puddles' picture observed by the scanning micro-x-ray diffraction technique. These demonstrate that high-frequency dielectric spectroscopy can be utilized for investigating the various order phases in other transition metal oxides by considering their intrinsic responses. [ABSTRACT FROM AUTHOR]

Tin oxide (SnO2) holds promise in thermoelectric applications. The paper explores the preparation of SnO2 nanoparticles by employing various methods. Synthesis of SnO2 material is carried out using a comparison of several methods, including the hydrothermal method, co-precipitation method, and co- precipitation sonication. This comparison aims to identify the most efficient method for SnO2 synthesis with the best performance in thermoelectric applications. Characterization techniques such as SEM-EDX, XRD, and thermoelectric properties, electrical resistivity, electrical conductivity were utilized. Results obtained in the thermoelectric performance test, specifically electrical resistivity and electrical conductivity, showed a decrease in resistivity with increasing temperature for all three methods. In the hydrothermal method, excessively high temperatures led to difficulties in accurately measuring electrical resistivity. The co- precipitation method proved to be the most effective for SnO2 synthesis.

Supercapacitor electrodes based on porous activated carbon from a blend of cassava tubers and bamboo stems were successfully synthesized using a chemical activation method with a 4M KOH activator. In this study, we characterized the morphological structure of porous activated carbon blended from cassava tubers and bamboo stems using SEM, while the electrochemical performance was tested using GCD, CV, and EIS. The porous activated carbon blend derived from cassava tubers and bamboo stems exhibits a micro-meso pore morphology, resulting in superior electrolyte ion storage capacity when compared to the carbon precursors of cassava tubers and bamboo stems. The porous activated carbon blend from cassava tubers and bamboo stems, serving as a supercapacitor electrode, demonstrates specific capacitance, energy density, and power density values of 43.44 F/g, 4.81 Wh/kg, and 178.64 W/kg, respectively. The CV curve results show that the supercapacitor electrode has EDLC properties, with Rs and Rct of 15.52 Ω and 7.40 Ω. The results of the research provide a valuable contribution to the development of efficient and sustainable electrochemical materials, with potential broad applications in energy storage technologies.

Batteries are one of the storage media for electrical energy whose development is quite significant. A battery if there is no monitoring on its use will cause damage to the battery itself such as a battery that heats up quickly, leaks and bubbles. Currently, there are quite a lot of battery management systems available as battery monitoring and controlling modules to avoid overcharge, overdischarge and overcurrent that have the potential to damage battery quality. Tests on the battery management system (BMS) as a monitoring and controlling module are carried out in this article. Tests were carried out on BMS 1S, 2S, and 3S series with Li-Ion 18650 2200mAh 3.7 V Battery type. The results of the BMS controling test show that the overcharging and overdischarging protection functions can work well. While the results of monitoring the cut off value of overcharging protection of each BMS are 3.7 V, 7.2 V, and 11.1 V. The cut off value of overdischarging protection of each BMS is 3.23 V, 6.1 V, and 9.23 V.

Thermoelectric is one of the energy harvesters that can convert heat energy into electrical energy currently being developed. One of the thermoelectric materials most studied is Antimony Cobalt (CoSb3). The unique crystal structure, high carrier mobility, and high electrical conductivity of CoSb3 -based skutterudite is considered promising thermoelectric material for medium-temperature thermoelectric applications. A comprehensive study is needed to investigate scientific information and its application by modifying the combination of the two phases by making CoSb3 /rGO nanocomposites. CoSb3 was synthesized using the polyol method, which was then composited with rGO material and made into thin films. It is found that adding rGO increases electrical conductivity. The addition of rGO composite showed that the local crystal structure experienced a decrease in peak intensity in the (0 1 3) plane. It was found that the grains were agglomerated. Furthermore, adding the rGO gives rise to a change in the size of the gr ins. The resulting electrical conductivity range from (1.4–4)×103 Ω-1 cm-1 at room temperature. While at 320 K, the value of the Seebeck Coefficient composite rGO 20% is around 1.2 V/K.

We investigate the fabrication of photosensor devices based on dye sensitized solar cells (DSSC). DSSC photovoltaic cells use solar light energy to trigger chemical reactions as a source of electrical energy. DSSC has several advantages, namely low production costs, environmental friendliness, easy fabrication, and high-power conversion efficiency. Therefore, DSSC is ideal for use as a photosensor. Most DSSCs use a wet electrolyte to provide ionic conductivity to the photoanode. However, long-term use of liquid electrolyte causes corrosion which can reduce the stability of the resulting current. In this research, yttria stabilized zirconia (YSZ) solid electrolyte was used to prevent corrosion of the photoanode. Samples were characterized using XRD, SEM, UV-Vis and photoresponse. The XRD results show the crystallinity of nanoporous TiO2 and YSZ. SEM results show that the average particle size distribution of TiO2 /YSZ DSSC cells is 315 nm. The sensitivity, rise and fall times of the photosensor have been calculated by varying the counter electrode when testing the photoresponse. Finally, Graphene as a counter showed higher voltage and current compared to AC which is 0.2 V and 0.05 µA.

Supercapacitor are one of the most environmentally friendly electrical energy storage devices. Improvement of supercapacitor performance continues to be carried out by combining active materials and transition metal oxides/hydroxides. In this study, a composite electrode material based on activated carbon with a mass percent variation of CoS2 has been successfully carried out. The composition of Ni(OH)2 - CoS2 /Graphene Nanosheet//Carbon electrode consists of 10, 15, and 20% CoS2 . The electrodes were then characterized using X-Ray Diffraction (XRD), Scanning Electron Microscope - Energy Dispersive X-ray (SEM-EDX). The research was continued by fabricating a symmetric coin cell. Supercapacitor device performance was characterized using Cyclic Voltammetry (CV), Charge-Discharge (CD) and Electrochemical Impedance Spectroscopy (EIS). The morphology of activated carbon shows porous chunks that are beneficial in the electrolyte ion adsorption process. While CoS2 and Ni(OH)2 materials indicated in bulk form. Characterization results show the most optimum sample is in the 15% CoS2 sample with EIS characterization showing the smallest equivalent series resistance (ESR) of 0.81 Ω. CD characterization results were able to have specific capacitance, energy density and power density of 58.25 Fg-1, 1.59 Wh/kg, and 70.49 W/kg respectively and were able to survive up to 88.84% after 1000 test.

Problem-solving is one of the essential and crucial skills for physical learning. This study describes the problem-solving skills of college students taking physics education programs and their incorrect answers on simple electrical circuits topic. We used four essay questions representing the series, parallel, combined series-parallel, and double-loop electrical circuits concepts to measure their problem-solving skills. Meanwhile, for describing their problem-solving skills, we used five categories of problem-solving processes, consisting of useful description (UD), physics approach (PA), specific application of physics (SAP), mathematical procedures (MP), and logical progression (LP). Further, to identify their mistakes, we examined the general mistakes in each problem-solving process. Our analysis results suggested that the college students taking the physics education program have relatively high problem-solving skills in the UD and PA categories. Still, they have low skills in SAP and MP categories, with poor ability in the LP category. Their mistakes were mostly observed in drawing complete electrical circuits and the circuits with missing and changing components (UD category), the correlation between each physic concept, law, and principle with the simple electrical circuits topic (PA category), confusion and inconsistency to correctly determine the + or - symbols for every source of voltage and difficulty in using the Kirchoff's second law following the loop direction. Besides, the participants also frequently used incorrect V, and I value on the problem being reviewed (SAP category), did not re-evaluate the order and completeness of their answer, as well as the logical reasoning for the obtained V and I from their problem-solving process based on the scientific and physic concepts and characteristics (LP category). [ABSTRACT FROM AUTHOR]