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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.

Since energy storage is an essential component of global energy development, starting with batteries, fuel cells, and supercapacitors, it is an important topic of particular concern. Supercapacitors continue to be developed due to their high power density when compared to batteries, despite all of the benefits and drawbacks of the three. Activated carbon (AC) is materials that frequently utilized as a supercapacitor electrode due to the high surface area. Metal oxides such as manganese dioxide (MnO2) with high teoritical specific capacitance which loaded in activated carbon will caused an improvement on supercapacitors electrochemical performance. The composite was fabricated using blending method with a mass difference of MnO2, then deposited on a porous Ni-foam substrate. Ni-foam pores play as main role on the process of transferring electrolyte ions in the system so that the AC/MnO2 has, resulting a supercapacitor based AC-MnO2 15% nanocomposite with a gravimetric capacitance, energy density and power density of 79 F/g at 1 A/g, W/kg and Wh/kg respectively. The cell could maintain up to 93% after 100 cycles.

Silver nanowires (AgNWs) are promising materials due to their flexibility, high transmittance, high conductivity, and low sheet resistances to replace ITO (Indium Thin Oxide) based electrodes. In this work, we studied the Propylene Glycol and Glycerol addition in Ethylene Glycol solvent to form AgNWs with polyol method. AgNWs was made thin film by spin coating method (with 1 – 3 layers variation) in PET substrate at 3000 rpm. The best morphology AgNWs formed by EG: PG: Gliserol (7 : 0 : 3) solvent composition with average diameter, length, and thickness are 210.32 nm, 6.68 μm, and 2.1 μm respectively. In optical properties, transmittance of AgNWs thin film was in range of 54.6 – 70.6 %. The sheet resistance of 3 layers AgNWs thin film was 2.8 – 30.2 Ω/sq. Sheet resistance of AgNWs thin film was better than ITO-PET (transmittance 60% sheet resistance 45 Ω/sq).

Supercapacitors as one of the energy storage have attracted attention. The advantages of using carbon materials have so far been widely developed and researched as electrodes for supercapacitors, but their volumetric capacity is still less than optimal and less practical in long-term use. Manganese (III) oxide (Mn2O3) materials show great potential as electrodes with high theoretical specific capacitance. On the other hand, BiPO4 as an anode has added battery characteristics to get maximum results. The blending method is applied in the manufacture of composites deposited on an aluminum foil substrate. The electrochemical properties of the developed samples were studied by cyclic voltammetry (CV), Galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS). The electrochemical results showed that the best electrode-specific capacitance at 20% BiPO4 percentage reached 56 Fg-1 at a current density of 1 Ag-1 with a potential window of 2 V for 50 cycles. It is hoped that these results can provide information on the potential of using the material as an optimal electrode.

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]

A mental model (MM) is an internal representation of students' conceptual understanding. Currently, students have still had difficulties in explaining the physical state of elasticity of solid materials, at submicroscopic level. These difficulties call for this research. Through a mixed method, the study aimed to reveal the development and differences of students' mental models after physics learning with problem-based learning (PBL) and conventional methods. Indicators of students' mental models were adapted from SMD model. Findings suggested that the PBL resulted in more MM, whilst conventional classes emerged MM on the elastic and plastic objects. Meanwhile, the lowest MM achievements ware Hooke's Law for the PBL, and series and parallel springs for the conventional class. N-Gain values of the students' mental models at PBL and conventional classes were found to be 0.64 and 0.43 respectively. On the other hand, mental model scores of the PBL learning model was higher (23.77%) than those of the conventional learning model. Thus, it can be concluded that the PBL learning model is effective in improving the students' mental models of physics. This research recommends that students' understanding of physics concepts should be increased at macroscopic and sub-microscopic levels.

The research mixed method aims to investigate students' creative thinking skills about elasticity in physics. The students' creative thinking skills were measured by diagnostic tests developed by researchers and validated by theoretical physics. The instrument included several indicators of critical thinking skills including fluency, flexibility, originality, and elaboration. This study involved 58 students of 11th grade of public senior high school 8, Malang. The research findings showed that students who were learning with the PBL and conventional approach had good scores in originality and fluency. Particularly in the PBL classes, the highest scores of critical thinking skills were achieved on parallel and parallel spring topics, while in conventional classrooms, the highest scores of critical thinking skills were achieved on the stress, tension, and topic of Young's modulus. Both the PBL and conventional classes got the lowest score on Hooke's law topic. The t-test results showed that there was no difference between the pretest score of PBL students and the conventional student's pretest score. However, the difference was found in post-test scores. In conclusion, the PBL was recommended to develop or enhance students' creative thinking. Future research was expected to fully examine the effect of the PBL on student motivation, and high-level thinking with or without moderator variables. In addition, it was also necessary to conduct other researches that aims to analyze the relationship between pretest and post-test students in creative thinking after engaging in the PBL classes.