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The evolution of energy storage devices that have specific capacitance, high power density, and high energy density is an important for human life. Supercapacitor is a complimentary of replacement a battery that has been extensively developed. The supercapacitor shows the high capacity and power density. The disadvantage of energy density of supercapacitor may be overcome by combining with the advantage of battery in supercapattery. Supercapattery is an ideal type of energy storage because it has a good energy density of batteries and a greater power density of supercapacitors. Cobalt and Zinc are transition metal electrodes that have been widely studied as supercapacitor electrode materials because they have high conductivity and electrochemical activity. Here, Mn2O3 material has high redox and is non-toxic, so it has the potential to be used as electrode material in supercapattery. Initially, the two materials were synthesized into a composite paste which was then deposited on the substrate using the doctor blade method. Furthermore, the electrode M/Mn2O3 (M=Zn, Co) was arranged with a separator and the 1 M Na2SO4 electrolyte to forms a supercapattery. In this work, we have the specific capacitance of 46.95 F·g−1 for supercapattery (Zn/AC/Mn2O3//AC) and 21.83 F·g-1 for (Co/AC/Mn2O3//AC). [ABSTRACT FROM AUTHOR]

Photo-anodes based on TiO2 have been widely used in DSSC devices. However, TiO2 has a high rate of electron recombination, thus limiting the energy conversion of the DSSC. One of the strategies to increase TiO2 capability is to perform surface functionalization with other materials such as carbon. Carbon has a large specific surface area, high electron mobility, excellent optoelectronic and electrocatalytic properties. Activated Carbon (AC) is an allotrope of carbon with the highest surface area, while Black Carbon (BC) has better electrical conductivity. Surface area and electrical conductivity are important parameters to produce high-efficiency DSSC. In this research, the effect of TiO2/C (C=AC and BC) nanocomposites as a photo-anode for DSSC have been investigated. The TiO2/C photo-anode was fabricated by a doctor blade method. It is found that TiO2/C nanocomposite improves efficiency DSSC based on TiO2. The optimum performance was obtained on TiO2/AC photo-anode with an efficiency of 0.475%. [ABSTRACT FROM AUTHOR]

Green energy production for environmental protection and its sustainability has been a hot topic for the last decade. The solar source is one of the candidates for green energy to be developed in Indonesia. It is because of the tropical climate that makes Indonesia receives a lot of sun exposure. Besides, the development of green energy needs to be balanced with the development of better energy storage. The high-power density, long lifetime, and environmentally friendly are exciting and unique points of a supercapacitor. Research of photo-supercapacitor, which integrating solar cells with a supercapacitor, has been developed widely. This Integrated structure will capture and convert light energy into electrical energy then store it. Investigation on improving DSSC performance was carried out in many ways, such as a variation on dye materials, variation on the photoanode material, and other component variation, observations on the effects of temperature variations in the growth of photoanode materials, and investigation on the role of blocking layers and any others. To obtain a good start for the next investigation, we need a complete map of the recent progress on the integrated photo-supercapacitors, mainly the device constructed from EDLC and DSSC. This review article is focused on summarizes current trends in the structure and performance of integrated EDLC Supercapacitor with DSSC. The optimized additional blocking layer in the DSSC section for integrated photo-supercapacitors devices is also proposed. [ABSTRACT FROM AUTHOR]

The development of thermoelectric device engineering has begun with the exploration and innovation of the use of new materials, defect engineering, doping engineering, and material mixing experiments. In previous studies, modifications have been made to the GO/rGO thermoelectric by doping with atom S but in previous studies have not conducted research on other atomic doping and the influence of doping concentrations. In this study, graphene oxide-based thermoelectric devices were doped by phosphorus and nitrogen atoms and modifications to the width of rxGO in the xGO /rxGO pair to get different areas. xGO materials were synthesized with added ultrasonic wave technique from graphene oxide material, then deposition to polyimide substrates. The fabrication process was done to form PGO/rPGO line modification of 0.5/0.25, 0.5/0.5, 0.5/0.75 mm and NGO/rNGO line modification of 0.75/0.75, 0.75/1.00 mm for using irradiation laser technique with length wave 405 nm and power 1.5 W. The characterizations used are X-Ray Diffraction, SEM, Temperature sensor and I-V. The voltage comparisons result of modification rPGO width line dT=10K were rPGO line width 0.25 mm>0.5 mm>0.75 mm (0.201, 0.165, and 0.126 Volts) Volt, as well as the seebeck coefficients comparison result were rPGO line width 0.25 mm>0.5 mm >0.75 mm (3.33, 2.95, 2.18) x 10−4 V/K. The voltage comparisons result of modification rPGO width line dT=10K were rNGO line width 0.75 mm>1.0 mm (0.47 and 0.4) Volt, as well as the seebeck coefficients comparison result were rNGO line width 0.75 mm>1.0 mm (2.52, 2.47)×10−2 V/K. [ABSTRACT FROM AUTHOR]

Energy storage continues to be a growing research topic. Supercapacitors are a good new choice of energy storage devices because they have good performance with high-density values, relatively fast charging, long-lasting lifetime, and are included in environmentally friendly technologies. The development of materials and structures in an extensive manner continues to be studied. Materials that can support energy storage devices have high capacitance, such as Activated Carbon (AC) and Bismuth Phosphate (BiPO4) as electrode materials. However, the energy density of carbon-based supercapacitors is still low. On the other hand, BiPO4 has good crystallinity and stability, high thermal and chemical properties, and has an ideal redox-active specificity as a supercapacitor electrode material. There is a lot of research on supercapacitor materials that have been released. The article summarizes current trends in the development of supercapacitor material synthesis and supercapacitor performance, particularly AC-BiPO4−based electrodes. The use of BiPO4 phosphate metal materials optimized to improve the performance of the supercapacitor electrode material is also proposed. Several supercapacitor material applications and new developments of supercapacitors and prospect analysis are also presented in this report. [ABSTRACT FROM AUTHOR]

A novel PVA/TiO2 nanofibers composite membranes that can be used for photocatalytic applications are synthesized by electrospinning methods. These new nanofibers membranes are prepared by better processing of the electrospun solution with the addition of sonication and surfactants. PVA/TiO2 composite nanofibers were observed by the characterization of SEM, EDAX, and FTIR. The characterization results showed the PVA/TiO2 composite nanofibers membranes have a good performance of photocatalytic. FTIR results showed functional PVA groups, and EDAX results showed TiO2 successfully inserted into the nanofibers membrane. The effects of processing with certain treatments, such as sonication and surfactant addition to the morphology and photocatalytic properties, were studied in the experiment. EDAX characterization shows that nanofibers with sonication have a TiO2 distribution along with an increase in the percentage of TiO2 up to 10.20%. This indicates that sonication can increase the electrospun solution to be more homogeneous. Nanofibers, with the addition of surfactants, have better TiO2 distribution, along with an increase in the percentage of TiO2 to 16.21%. The dye degradation ability of the PVA/TiO2 composite nanofibre membrane was investigated by the methylene blue photodegradation test under UV light. Methylene blue degradation was measured by UV vis spectroscopy. The photocatalytic activity of the PVA/TiO2 composite nanofibre membrane reduced Methylene Blue up to 40%. Sonication treatment increases photocatalytic activity by up to 60%, and the addition of surfactants increases photocatalytic activity by up to 80%. [ABSTRACT FROM AUTHOR]

SrTiO3 perovskite possesses high dielectric properties and is potentially applicable for a high-temperature thermoelectric as well as supercapacitor materials. Theoretically, the physical properties of SrTiO3 can be improved by the doping process. Modification of local structure changes crystal field or geometric distortion will, in turn, influence its electrical conductivity. Currently, SrTiO3 has been widely studied with various dopants. However, there has not been a comprehensive study about structural modification using multivalent magnetic ion of Chromium (Cr) and external magnetic fields on the electrical conductivity. Cr ions have various valences of 2+, 3+, 4+, 5+, 6+, and the symmetry of 4h with six coordination numbers, which can change the local structure of SrTiO3. Besides, the radius of Ti ion in SrTiO3 is about 67 pm with 4+ valence, while Cr has the symmetry of 4h for the 3+ valence. Under these conditions, Cr is expected to reduce the lattice parameters and a slight shift of apical oxygen to the basal plane of its local octahedral structure. Since Cr interacts with an electromagnetic field in the range of visible light, it might be expected that this compound would show a shift of bandgap energy. As the valence also changes to a possible mixed state, the physical properties may exist in complex states. SrTi1-xCrxO3 samples were prepared via solid-state reaction in the various molar ratio of Cr doping. The phase and structure were analyzed using X-ray Diffraction. XRD confirmed that the SrTi1-xCrxO3 compounds phase was successfully formed, and a slight change in lattice parameters was observed. The local octahedral six-fold symmetry structure of SrTi1-xCrxO3 compounds also changed to be tetragonal with the presence of Cr. Based on the EDX data, the composition of SrTi1-xCrxO3 compounds corresponded to the designated composition. Furthermore, the magnetic field induced I-V conductivity measurement showed that higher Cr fraction enhanced its electrical conductivity. SrTi1-xCrxO3 (x = 0, 0.02, 0.04, and 0.1) optical band gap analysis from UV-Vis spectroscopy showed that the bandgap is in the range of semiconductor materials. [ABSTRACT FROM AUTHOR]

Energy is a major requirement in everyday life. The harvesting energy, as well as the storing energy, are crucial to being developed. Many individual types of research of DSSC or other solar cells systems, as well as the energy storage systems, have greatly improved. Many disadvantages are arising for a separated device e.g. loss of converted energy from solar cell, or need other expensive devices for unused converted energy. To overcome the problem, It is necessary to combine the solar cells and their storage in one integrated system. In this report, we show the charging performance of electrical energy from DSSC into a supercapacitor section. In this study, we simply describe the synthesis of various photoanodes of SnO2:TiO2 composite nanoparticles for a various fraction of wt% TiO2 i.e. 0, 9, 18, 27, 36, and 100%. The films have been prepared using the screen-printing method followed by blending with dye β-carotene and combined an additional layer of ZnO symmetric supercapacitor to build a solar-supercapacitor. It is found that TiO2 and SnO2 particles were successfully synthesized with the grain size ranged from 8.9 nm to 26 nm. The gap energy produced by SnO2/TiO2 composite nanoparticles is 3.07 to 3.15 eV. The addition of TiO2 nanoparticles increases the efficiency of solar cells. The performance of optimum solar cell SnO2:TiO2 composite nanoparticle showed by 36 wt% TiO2 device with Jsc, Voc, Fill Factor, and the efficiency of 0.388 mA, 0.806 V, 0.452, and 0.819% respectively. The charging from DSSC into supercapacitor was measured to btain their capacitance. It is shown that the supercapacitor section can store the energy produced by the conversion of light into electricity in the solar cell section. [ABSTRACT FROM AUTHOR]

Energy demand is increasing significantly, while conventional energy resources. Carried out by developing and exploring materials which are potentially applied as an alternative renewable energy device. Nowadays, the utilization of thermal energy attracts the research interest due to its abundant quantities. Thus, thermoelectric as a thermal conversion device into electrical energy is the best alternative for confronting this matter. Thermoelectric studies continue to be encouraged, one of them is SrTiO3 based material. For investigating the scientific information and its application, a comprehensive study was needed by modifying the local structure using Bi dopant on SrTi1-xBixO3 system. SrTi1-xBixO3 was prepared via solid-state reaction followed by calcination, molding process, and sintering at 860 °C. In this work, the various molar ratio of Bi doping was performed. Substitution of Bi in Ti position of SrTiO3 was intended to find its potential as a high-temperature thermoelectric material. XRD identified cubic crystal structure of SrTi1-xBixO3 with a space group of P m -3 m. Cell dimensions different for all fractions, the biggest one was performed by x = 0.10. Electrical conductivity of samples induced by thermal condition relatively increase as the fractions larger. The linear fit of UV-Vis Spectrophotometer data confirmed that SrTi1-xBixO3 was classified as semiconductor material with a wide bandgap which is potentially applied for the thermoelectric device. [ABSTRACT FROM AUTHOR]

Due to sustainable energy promising, one technology that has high efficiency and suitable for a friendly environmental case is a Fuel Cell. One type of fuel cells is proton exchange membrane fuel cell (PEMFC), which shows low temperature, high power density, fast response, and zero emissions. A single fuel cell produces enough electricity for only the smallest applications. However, individual fuel cell are typically combine in series into a fuel cell stack. These procesess determaines the kind of chemical reactions taht take place in the cell, the kind of catalysts requaired, the temperature range in which the cell can be operate and other factor are needed. Therefore, we propose that process of the combining procesess is introduced using ebook accomplished with Augmented Reality (AR) technology. AR is a virtual object which can be used for interaction simultaneously, so using this technology, the detail process can be shown in detail when ebook’s user want to explore more the process. This paper described integrating AR to introduce the process and possible interaction of user to explore the dynamic system of the fuel cell. This integrating will be analyzed according to experts justice on the designed of AR ebook. [ABSTRACT FROM AUTHOR]

Material research for energy storage is increasing in an effort to find alternative renewable energy devices. A lot of thermal energy wasted in everyday life. Research for various alternative high-capacitance supercapacitor materials continues to be encouraged. SrTiO3 shows good electrical and dielectric properties, as wellas defect induced structure. Modification of local structure using Pb dopant on the SrTi1-xPbxO3 was applied for exploring the scientific information and its potential applications intensively. The synthesis of SrTi1-xPbxO3 was prepared by solid-state reaction method. The powder was then calcined, pressed into a pellet, and subsequently sintered at 860°C. Various fraction of lead (Pb) dopants were carried out in 0.00; 0.02; 0.04; 0.06; 0.08; 0.1 molar ratio. The structure, morphology, and supercapacitor properties of SrTi1-xPbxO3 composite powder was performed by using X-Ray Diffraction, UV-Vis, IV temperature-induced conductivity and CV EIS. XRD data analysis with Cu-Kα wavelength indicated the single phase was identified and a slight change in lattice parameters was observed. Sixfold symmetry of the local octahedral structure also changed to a tetragonal structure after introducing the amount ofPb element. For investigating electrical properties of SrTi1-xPbxO3, I-V meter was applied. Furthermore, electrical conductivity and dielectric constant will be discussed in detail. Loading higher Pb fraction promoted the electrical conductivity measured at various temperatures. Increasing conductivity is one indicator that this system potentially enhanced the electronic exchange of supercapacitor in SrTi1-xPbxO3 system. [ABSTRACT FROM AUTHOR]

Many efforts on the improvement of students’ mental models have been reported. However, many of them were only explore mental models which are possesed by students. In this work, we report the enhancing of students’ mental models on heat and temperature deeper than those reported previously. We used the experiment class that study by argument-driven inquiry learning and the control class that study by conventional learning. The data were obtained through pre- and post-tests using mental models instrument. The resulted data were grouped into three categories, i.e., scientific, synthetic, and initial. We employed Mann-Whitney U test and cross-tabulation to evaluate the enhancement of students’ mental models. We found a significant increase in post-test scores in the experiment class and the students’ frequency in the scientific group. Furthermore, it was found that a total of students’ post-test scores in the experiment class increased more significant than the control class. The difference in enhancement shows that argument-driven inquiry learning gives an impact better than conventional class. Furthermore, we also discuss differences in student’s understanding. [ABSTRACT FROM AUTHOR]

Nanofiber PVA/Chitosan/TiO2 have been prepared by electrospinning method. Electrospinning was performed at a voltage 15 kV, with a tip-collector distance of 14 cm. A novel nanofibers mat was fabricated in various contents of PVA, Chitosan, and TiO2. The structure of PVA/Chitosan/TiO2 was examined by FTIR, XRD, and SEM-EDAX. The results showed that PVA/Chitosan/TiO2 nanofiber was successfully formed. SEM observation showed that the fiber had several hundred nanometers with a smooth surface and distributed randomly. It was also observed that nanofibers containing chitosan show smaller diameter than that of without chitosan. The beads on the nanofibers are decreased by adding TiO2 nanoparticles into the electrospun solution. [ABSTRACT FROM AUTHOR]

Numerous studies on glass ceramic compounds have been conducted intensively. Two major problems to be solved are to simplify the fabrication process by reducing melting temperature as well as improving various properties for various fields of technological application. To control the dielectric constant, the researchers generally use a specific dopant. So far there is no comprehensive study to control the dielectric constant driven by both of dopant and light intensity. In this study it is used Al2O3 dopant to increase the light induced dielectric constant of the glass. The source of silica was taken from local silica sands of Bancar Tuban. The sands were firstly leached using hydrochloric acid to improve the purity of silica which was investigated by means of XRF. Fabricating the glass samples were performed by using melting-glass method. Silica powder was mixed with various ratio of SiO2:Na2CO3:PbO:Al2O3. Subsequently, a mixture of various Al2O3 doped lead silicate glasses were melted at 970°C and directy continued by annealed at 300°C. The samples were investigated by XRD, FTIR, SEM-EDX and measuring dielectric constant was done using dc-capacitance meter with various light intensities. The investigation result of XRD patterns showed that the crystal structures of the samples are amorphous state. The introduction of Al2O3 does not alter the crystal structure, but significantly change the structure of the functional glass bonding PbO-SiO2 which was shown by the FTIR spectra. It was noted that some new peak peaks were exist in the doped samples. Measuring result of dielectricity shows that the dielectric constant of glass increases with the addition of Al2O3. Increasing the light intensity gives rise to increase their dielectric constant in general. A detail observation of the dielectric seen that there are discontinuous step-like of dielectric. Most likely a specific quantization mechanism occurs when glass exposed under light. [ABSTRACT FROM AUTHOR]

Natural polymers can be extracted from leaf or stem of plants. Pterocarpus Indicus W. (PIW) and Jatropha Multifida L. (JIL) plants are good candidate as natural polymer sources. PIW and JIW polymers contain chemical compound so-called flavonoids which has C6-C3-C6 carbons conjugated configuration. The renewable type of polymer as well as their abundancy of flavonoid provide us to explore their physical properties. A number of research have been reported related to broad synthesis method and mechanical properties. So far there is no specific report of electrical conductivity associated to PIW and JIL natural polymers. In order to obtain electrical conductivity and its crystallinity of the extracted polymer films, it was induced on them a various fraction of silver nano particles. The film has been prepared by means of spin coating method on nickel substrate. It was revealed that FTIR spectra confirm the existing of rutine flavonoid. The crystallinity of the samples increase from 0.66%, to 4.11% associated to the respective various of silver fractions of 0.1 M to 0.5 M. SEM images show that there are some grains of silver in the film. The nature of electric conductivity increases a long with the addition of silver. The electrical conductivity increase significantly from 3.22 S/cm, to 542.85 S/cm. On the other hand, PIW films also shows similar trends that increase of Ag induce the increase its crystallinity as well as its electrical conductivity at semiconducting level. This result opens a prospective research and application of the green renewable polymer as optoelectronic materials. [ABSTRACT FROM AUTHOR]

Natural polymers can be extracted from leaf or stem of plants. Pterocarpus Indicus W. (PIW) and Jatropha Multifida L. (JIL) plants are good candidate as natural polymer sources. PIW and JIW polymers contain chemical compound so-called flavonoids which has C6-C3-C6 carbons conjugated configuration. The renewable type of polymer as well as their abundancy of flavonoid provide us to explore their physical properties. A number of research have been reported related to broad synthesis method and mechanical properties. So far there is no specific report of electrical conductivity associated to PIW and JIL natural polymers. In order to obtain electrical conductivity and its crystallinity of the extracted polymer films, it was induced on them a various fraction of silver nano particles. The film has been prepared by means of spin coating method on nickel substrate. It was revealed that FTIR spectra confirm the existing of rutine flavonoid. The crystallinity of the samples increase from 0.66%, to 4.11% associated to the respective various of silver fractions of 0.1 M to 0.5 M. SEM images show that there are some grains of silver in the film. The nature of electric conductivity increases a long with the addition of silver. The electrical conductivity increase significantly from 3.22 S/cm, to 542.85 S/cm. On the other hand, PIW films also shows similar trends that increase of Ag induce the increase its crystallinity as well as its electrical conductivity at semiconducting level. This result opens a prospective research and application of the green renewable polymer as optoelectronic materials. [ABSTRACT FROM AUTHOR]

TiO2/SWCNT nanocomposite has been successfully synthesized by the sol-gel method. Single-walled carbon nanotubes (SWCNT) functionalized with acid. TiO2/SWCNT composite was coated on the cork with a dip-coating technique. The crystal structure, morphology, and physicochemical properties of the composites were characterized by FTIR, XRD, SEM-EDX, SEM mapping, and UV-Vis spectra. FTIR data obtained functional groups of TiO2 and carbon. XRD test shows the crystal structure and shape of the nanoparticle material. SEM test was found that TiO2 was firmly attached to the sidewall of the SWCNT. The performance test of TiO2/SWCNT composite was evaluated by monitoring the degradation rate of methylene blue (MB) under a solar simulator. There was a significant decrease in the concentration of methylene blue (MB) when TiO2/SWCNT composite coated on the cork was added. After degradation for 2 hours, the results of the effectiveness of TiO2/SWCNT composite are approximately 99%. The photocatalytic activity of the TiO2/SWCNT nanocomposite in this experiment was influenced by the different compositions of TiO2 and SWCNT, the method used, the success of coating on the cork and light from the solar simulator. [ABSTRACT FROM AUTHOR]

Nowadays there's a high demand for Electrochemical Energy Storage which has the high specific capacitance, power density, and energy density. To address this need, supercappteries are being developed that can combine the merits of batteries and supercapacitor into one device as innovative hybrid EES devices. Herein, Mn2O3/GO/AC composite has been synthesized by using a simple procedure for blending and subsequent annealing procedure. This composite was applied as anode material in supercapatteries. With the mass variation Mn2O3 and the scan rate variation, it shown that 20 wt% Mn2O3 at 10 mV/s has the highest spesific capacitance among them, 18.93 F/g, and 2.63 Wh/kg for energy density. [ABSTRACT FROM AUTHOR]

The design innovation and composition of TiO2 as a photoanode have been continuously studied in recent years to improve the photoconversion performance of Dye-sensitized Solar Cells (DSSC). The important components in the formation of TiO2 paste are solid content, solvents, and organic compounds as binders. In terms of solvents, water or simple alcohol are not suitable for screen printing methods, because cracking will occur after the annealing process by rapid evaporation. In this report, we investigated the addition of nitric acid (HNO3) and ethyl cellulose (CH2CH3) as a binder for optimize the overall DSSC performance. TiO2 photoanode was synthesized by screen printing method through the initial stage of making blocking layer with spin coating method. The effect of nitric acid and ethyl cellulose on, TiO2 powder was studied intensively to determine the best photoconversion performance. TiO2 films were prepared by varying the process without and with post-treatment. The XRD pattern confirmed the presence of a pure anatase phase of TiO2. The morphology of the photoanodes surface area were studied through SEM characterization. The characteristics of J-V shows an increasing in photocurrent and efficiency through the post-treatment process. DSSCs based on TiO2-HNO3 photoanode with post-treatment exhibited a highest efficiency of 3.59%. We found that the sample with post-treatment process have a smaller impedance than sample without post-treatment with charge transfer resistance (RCT) of 10 Ω and 23 Ω, respectively. It may indicate that the TiO2 film with post-treatment have a better interconnection then charge transfer and charge extraction process are more effective and resulting higher efficiency. [ABSTRACT FROM AUTHOR]

Dye Sensitized, Solar Cell (DSSC) is the most attractive technology in third-generation solar cells due to its simple operation, easy fabrication, great use of raw materials, and ability to be flexible panels. One of the materials that are often used in DSSC is titanium dioxide. Titanium dioxide is a semiconductor material formed from Ti4+ ions and O2- ions. Titania has a stable chemical structure under ultraviolet light. The anatase phase of titania has high photocatalytic activity compared to other phases, so it is widely used for DSSC applications. One of the important components in DSSC is the stability and morphology of the photoanode, so that in this study additional treatment will be carried out on the TiO2 photoanode. The addition of this treatment aims to improve the interconnection of TiO2. One of the materials used as a treatment is TTIP. This treatment is carried out by dip coating. From the experiments, the data shows that the efficiency increased up to 30% after treatment, from 3.78% to 5.45%. This study can explain through the morphology of the SEM characterization results where it is seen that there is a TiO2 layer with a decrease in porosity from 64% to 60% after treatment. In addition, this treatment also shows an increase in the effectiveness of TiO2 charge transfer as indicated by the results of impedance analysis where the RCT of the sample without treatment is 15 ohms and the sample with treatment is 8 ohms. [ABSTRACT FROM AUTHOR]

The discovery of delafossite compound has encouraged more rapid technological developments particularly in transparent electronic devices. Copper oxide-based transparent thin films delafossite semiconductor recently give much attention in the field of optoelectronic technology, after the discovery of p-type CuAlO2. The potential applications of a p-type semiconductor transparent conductive oxides (TCO) have been applied in broad field of optoelectronics. To explore a broad physical properties interms of magnetic conducting subtitution is understudied. In this work we report the fabrication of delafossite film on Ni substrate and their characterization of CuAl1-xMxO2 delafossite compounds doped with Cr3+ and Fe3+ from the raw material of Cu(NO3)2.3H2O, Al(NO3)3.9H2O, Fe(NO3)3.9H2O and Cr (NO3)3.9H2O. The films were prepared using spin coating through a sol-gel technique at various concentrations of x = 0, 0.03, 0.04, and 0.05 for chromium and x = 0, 0.02, 0.04, 0.06, and 0.08 for iron doped. Crystal and microstructure were characterized by means of Cu-Ka Bragg-Brentano X-RD followed by High Score Plus and SEM-EDAX. The dielectric constants of the films were characterized using LCR meter. It was found that the CuAl1-xMxO2/Ni delafossite films were successfully fabricated. The CuAl1-xFexO2 compound crystallized with lattice parameters of a = b ranged from 2.8603 Å to 2.8675 Å and c ranged from 16.9576 to 17.0763 Å. The increase of the dopant give rise to the increase of the lattice parameters. Since iron has bigger ionic radius (69 pm) than original site of Al3+ with radius of 53 pm the crystal volume lattice also increase. Further analyses of increasing volume of the crystal, as expected, affected to the decreasing of its dielectric constant. The similar trends also shown by Cr3+ doped of CuAl1-xCrxO2 films with smaller effects. [ABSTRACT FROM AUTHOR]

Nanosilver is currently one of the most common engineered nanomaterials and is used in many applications that lead to the release of silver nanoparticles and silver ions into aqueous systems. Nanosilver also possesses enhanced antimicrobial activity and bioavailability that may less environmental risk compared with other manufactured nanomaterials. Described in this research are the synthesis of silver nanoparticle produced by chemical reduction from silver nitrate (AgNO3) solution. As a reducing agent, Sodium Borohydride (NaBH4) was used and mercaptosuccinic Acid (MSA) as stabilizer to prevent the nanoparticle from aglomerating. It was also used two kinds of solvent, they are water and methanol. In typical experiment MSA was dissolve in methanol with a number of variation of molarity i.e. 0,03 M, 0,06 M, 0,12 M, 0,15 M, and the mixture was kept under vigorous stirring in an ice bath. A solution of silver nitrate of 340 mg in 6,792 ml water was added. A freshly prepared aqueous solution of sodium borohydride (756,6 mL in 100 mL of water) was added drop wisely. The solution was kept for half an hour for stirring and were allowed to settle down in methanol. The obtained samples then characterized by means of x-ray diffractometer, and scanning electron microscopy, as well as transmission electron microscopy to obtain their structures of silver nanoparticles, morphology, and sizes. It is shown that diameter of silver nanoparticle sized about 24.3 nm (Ag@MSA 0.03 M), 20.4 nm (Ag@MSA 0.06 M), 16.8 nm (Ag@MSA 0.12 M), 16.9 nm (Ag@MSA 0.15 M) which was calculated by Scherrer formula by taking the FWHM from fitting to Gaussian. The phases and lattice parameter showed that there is no significant change in its volume by increasing molarity of stabilizer. In contrast, the size of particles is decreasing. [ABSTRACT FROM AUTHOR]

Polyaniline (PANi) is one of conductive polymers which are widely studied. PANi has unique in the structure and physical properties that can be controlled by doping. In this work we report the role of CuCl2 and FeCl3 in the crystalline and dielectric properties of PANi/Ag films which was performed by means spin coating method. We employed sonochemical technic to form solutions of PANi ES II prior to spin coating method. The variation of FeCl3 and CuCl2 doped were used in the range of 0 M - 0.5 M. FTIR spectra of PANi EB and PANi ES clarified that the PANis were successfully synthesized. The crystallinity of the films were examined by menas of X-ray diffraction (XRD). While the polymeric grains were evaluated using SEM which is confirmed with the grain size analyses from X-RD data. Dielectric properties shows that introducing Fe and Cu doped could decrease their dielectric constant. The decreasing of dielectric constant was also achieved by increasing frequency. [ABSTRACT FROM AUTHOR]

The aim of this study was to fabricate an HAp/Zn-ferrite nanocomposite for drug delivery application. The HAp/Zn-ferrite nanocomposite was synthesized using the coprecipitation method. The nanocomposite obtained was then characterized using XRD, SEM, and FTIR. Meanwhile, the drug delivery performance of the synthesized nanocomposite was characterized with UV-Vis to determine the loading and releasing capabilities. The result of XRD data analysis showed that the HAp phase had a crystallite size of 10.0 nm with a hexagonal crystal system. The presence of a Zn-ferrite was detected with a cubic spinel system with a crystallite size of 13.4 nm. The results of the FTIR analysis showed that the presence of the HAp phase was indicated by the presence of PO43-, CO32- and O-H groups. Meanwhile, the Zn-ferrite phase was indicated by Fe-O and Zn-O vibrations. The surfactant element was detected by the vibrations of CH2, COO−, C-C, and O-H groups. Based on the SEM image, it was known that the aggregated particle size was 60 nm with spherical morphology in the form of granular. The result of the UV-Vis data analysis showed that the nanocomposite had the ability to load doxorubicin with a capacity of 27.61 mg/g and the ability to release doxorubicin, which was relatively stable, reaching 79.15% in 300 minutes. [ABSTRACT FROM AUTHOR]

Newton's law plays an important role in learning mechanics and explaining real-life phenomena, but students find it difficult to understand. This study aimed to build students' conceptual understanding and to describe students' difficulties with Newton's law after the Argument-Driven Inquiry (ADI) model learning process is implemented. This study used a quasi-experiment (pre-and post-test) design Pre- and Post-test design with the research subject of 50 tenth grade students in public high schools in Pamekasan, Indonesia. Students are distributed into the experimental class (ADI learning) and the control class (conventional learning). The instrument of this study was Newton's law understanding test in the form of reasoned multiple-choice questions with a reliability of 0.82. The research data were analyzed by the Mann-Whitney U test, ANCOVA, N-gain, d-effect, and a description of the reasons for students' answers. The results showed that conceptual understanding was not influenced by the initial state, but rather influenced by the ADI model. Improved conceptual understanding in the experimental class (medium category) is higher one level compared to the control class (low category). After the learning process, both classes students still have difficulty in the concept of a=F/m and its application, and objects in an inertial frame. However, the difficulties of the conventional class students are compounded by the friction, and Newton's I, II, and III laws concepts. [ABSTRACT FROM AUTHOR]

An important goal of physics instruction is to facilitate the students to become an effective problem solver. However, researchers reveal that students' physics problem solving skills is quite low. In this respect, we have implemented modeling instruction to improve students problem solving skills in the topic of heat and temperature. The instruction has been piloted to 55 students of grade 12 of a high school in Batu, East Java. The students’ problem solving skills have been assessed using a rubric of problem solving developed by Docktor & Heller. By using mixed-methods, pretest-posttest analyses we found that the students’ problem solving skills increased with N-gain of 0.80. In addition, the students reasoning to solve the problems also improved from pretest to posttest. [ABSTRACT FROM AUTHOR]

In this research, we produced Co0.6Fe2.4O4 nanoparticles covered by natural surfactants from Syzygium polyanthum extract. The results of XRD analysis showed that the Co0.6Fe2.4O4 nanoparticles were successfully synthesized, which was indicated by the presence of the spinel phase without other phases. The Co0.6Fe2.4O4 nanoparticles had a particle size of 12.1 nm. SEM image indicated that the morphology of the nanoparticles was spherical and agglomerated with an average particle size value of 34.2 nm. Furthermore, the FTIR spectrum showed the vibrational peaks of C=C and C-H at the wavenumbers of 1633 cm−1 and 2881 cm−1, indicating the presence of the surfactant Syzygium polyanthum. At the wavenumbers of 500₋600 cm−1, the vibrational peaks of Fe-O and Co-O were overlapped, which indicated that the Co2+ ion has succeeded in replacing the position of the Fe3+ ion. Our data analysis results also captured that the Co0.6Fe2.4O4 nanoparticles using natural surfactants from Syzygium polyanthum are potential candidates as high-performance antifungal agents. [ABSTRACT FROM AUTHOR]

The development of a new generation of SWCNT/Si heterojunction solar cells has attracted great interest in research due to the extraordinary optoelectronic properties of single-walled carbon nanotube (SWCNT) materials. On the other hand, SWCNT has a weakness; namely, it is hydrophobic, so it is necessary to add hydrophilic functional groups to its surface so that it can be dispersed in organic solvents. In this study, we investigated the effect of functionalization treatment on SWCNT surfaces on solar cells performance. SWCNT is functioned by wet method using H2SO4 and HNO3 to form carboxylate groups along the SWCNT sidewalls. Characterization of samples using XRD to determine the F-SWCNT crystal phase and structure, SEM to characterized the morphology of the sample, FTIR to determine the functional group of the sample, and solar simulators to determine the efficiency of solar cells. Based on the solar simulator testing results, the power conversion efficiency increased significantly from 2.59% to 6.29% after functionalization treatment. [ABSTRACT FROM AUTHOR]

Although the application of thermoelectric in the various field has been implemented, the effort to search new materials remain actively conducted. Thermoelectric devices may help human life not only in harvesting renewable energy, but also reduce heat pollution. As a tropical country, Indonesia produces a lot of unused heats energy from various machines, households, or natural phenomena. The research to produce new materials, as well as their thermoelectric devices, are essential. Following our previous work, the CuS based materials may need to be improved the phase fraction, crystallite size, and crystallinity. The role of modifying ion fraction in the Cu site is expected to modify its local structure. A small different in ionic radii as well its valence may enrich the local distortion as well as their anisotropic heats and electrical conductivities. Shortly, the CuSNi was syntheized using modification of polyol method. The first step was dissolving raw materials using Tetraethylene glycol (TEG). All the process were kept in oxygene free condition. For the reason, we used a system which allowing a flowing nitrogen gas at a temperature of 150 °C and followed by centrifugation of the solution. The black powder was obtained after drying process using a vacuum desiccator. The black powder of CuSNi nanomaterials were characterized XRD, electrical conductivity and FTIR. [ABSTRACT FROM AUTHOR]

One of the hot materials in thermoelectric is the skutterudite CoSb3 compound, which shows excellent potential as a thermoelectric material because Sb-based skutterudite thermoelectric materials have high mobility, large atomic mass, and high electrical conductivity. The effort of substituting transition metal (Fe) or (Ni) ions at Co site is an attempt to modify the local distortion and increasing electrical conductivity. In this work, we report the synthesis of the skutterudite CoSb3 compound using a modified polyol method. We used CoCl2.6H2O, FeCl3.6H2O, NiCl2, and SbCl3 raw materials as precursors. During the process, we used polyvinylpyrrolidone (PVP) as a stabilizer. The precursors were reduced by NaBH4 in tetraethylene glycol (TEG) at 513 K in a nitrogen atmosphere with 30 minutes for holding times. The yielded products were characterized by XRD, SEM-EDX, FTIR, and electrical conductivity. From the analysis of XRD data, we found that the nanoparticles show grain size between 15 to 32 nm. The nanoparticles were mostly identified as the CoSb3 phase, and the other phase of CoSb2 was also detected. And then, from the analysis of SEM-EDX data, there was agglomeration in the samples so that the particles size become larger and unstable. The chemical bonds of samples actually in the wavenumber range below 500 cm-1. The electrical conductivity increased with increasing stoichiometry fractions of Co1-xFexSb3 (x = 0, 0.05, and 0.1) or Co1-xNixSb3 (x = 0, 0.15, and 0.2) indicating that the samples can be used as a raw material for the thermoelectric device. The values of electrical conductivity for samples lay between 103 to 104 Ω-1cm-1, which also indicates the samples were semiconductors. [ABSTRACT FROM AUTHOR]

Supercapacitor is able to provide fast charging rate, environmentally friendly and relatively abundant material availability. Manganese dioxide (MnO2) has a high potential to use as a supercapacitor electrode material because of its significant advantages compared to other metal oxides such as high specific capacitance due to the reversible redox reaction and affordable prices. Briefly, the experiment begins with the preparation of a composite solution with a variety of compositions that was deposited on the aluminum foil substrate as electrodes using the doctor blade method. The supercapacitor was packed in a coin cell with 1 M Et4NBF4. The symmetric supercapacitor cycled in the cell potential window of 0-2 V, exhibited excellent specific capacitance of 52.87 F g−1, with power density of 344.94 Wh kg−1 and maximum energy density of 21.84 Wh kg−1 with 82.23 % capacity retention for 100 cycles. [ABSTRACT FROM AUTHOR]

Supercapacitor has received considerable attention as a promising energy storage device due to its fast charging, excellent cyclic stability, and high-power density. Activated carbon is the main material used to make supercapacitor electrodes because it has a high theory-specific surface area reach of 2,685 m2g−1 and low cost. However, structure micropore activated carbon had poor ionic diffusion and transportability that make inefficient surface area utilization, long charge-discharge performance, and low cycle life. Therefore, continuous research is needed to improve supercapacitor performance by adding and modifying structure micropores to increase the performance of electrochemically active sites so that ionic diffusion is better. This research is focused on the influence of concentration PVP immersion 0 M and 0.06 M with the dehydrogenation method. The higher concentration PVP strongly influenced the microstructure, morphology, and electrochemical process. The activated carbon mesoporous was characterized by XRD, SEM – EDX, FTIR, BET, and Charge Discharge. Further, the supercapacitor with the best performance is shown by the highest concentration of PVP 0.06 M exhibited the highest specific capacitance, energy density, and power density of 83.83 F.g−1, 60.06 Wh kg−1, 454.24 Wkg−1. ACM-0.06 had highest cycle stability in the cell voltage of 0-2.4 V at a current density of 0.1 Ag−1, and maximum energy density is 58.96 Wh kg−1 with 95.82 % capacity retention after 25 cycles. [ABSTRACT FROM AUTHOR]

A fuel cell is well known as clean energy that can be categorized as a renewable energy source. Proton Exchange Membrane Fuel Cell (PEMFC) is one kind of fuel cell, which works in low temperatures using a simple structure. Regarding this advantage, PEMFC can be a chance for introducing fuel cell process to students in vocational high school with renewable energy majors. Reaching the goal requires a learning media that can show the structure and process using interactive educational kits. The educational kits are built as trainers, which could be more effective when integrated with smartphone applications. The application can work with multi-platform interactive media, such as augmented reality. Then, the educational kits named Robo-PEM were developed to introduce PEMFC implementation by using Science, Technology, Engineering, and Mathematics (STEM) model. The Robo-PEM consists of a trainer, job sheets, and material course, which are combined in the Robo-PEM application. The Robo-PEM educational kits were evaluated by learning media experts. The result shows that the Robo-PEM educational kits were valid and could be implemented for learning media in vocational high school. [ABSTRACT FROM AUTHOR]

One-dimensional (1D) nanostructures are known to contribute a straight pathway for electron transfer to achieve good device performance. Besides that, Titanium dioxide (TiO2) is a metal oxide semiconductor, investigated as a material with upstanding physical and chemical properties with excellent light sensitivity, good relialibility in the environment, and low synthesis costs. In this research, the composite of ZnO nanorod/TiO2 designed to become a semiconductor coating material for photoanodes to support the process of electron transport. In this research, hexagonal structures of ZnO nanorods were synthesized by various growth time of hydrothermal synthesis method. The growth time affects to ZnO nanorods was systematically investigated on ZnO nanorods/TiO2 composites by scanning electron microscopy. From the XRD analysis showed that the ZnO nanorods in a crystalline phase in ZnO nanorods/TiO2 composites. Its crystallinity increases with increasing hydrothermal duration. In addition, the hydrothermal duration of 5 hours resulted the largest diameter and thickness of ZnO nanorod. [ABSTRACT FROM AUTHOR]

Mangrove sediment has a unique environmental absorption characteristics, as it has two sources of sediment which are from allocthonous sediment and authochtonous sediment. In this research, the mangrove sediment samples are taken from Clungup Mangrove Conservation in Malang, East Java, Indonesia. The samples are taken from four spots around the mouth of the river, and four spots around mangrove conservation. Those samples are analyzed based on the magnetic characteristics and the element composition to reveal the magnetic properties and element composition so in the future they can be used as indicators to trace the source of magnetic minerals that are precipitated in the mangrove ecosystem. The magnetic susceptibility value based on mass for mangrove sediment around the river area has the range of (38,8-2130)x10-8m³kg-1, while for the conservation area has the range of (0,97-122,5)x10-8m³kg-1. Based on XRF analysis, the mangrove sediment both from the river area and mangrove conservation area has a non-metallic element S, Br, metallic element Ca, Si, Al, K, Ti, Sr, and heavy metallic element Fe, Ni, Cu, Cr, Zn, Zr, Mn, and V, with the highest concentration of Fe element followed by Ca, Al, Si, and Ti. [ABSTRACT FROM AUTHOR]

A simple method based on alkaline extraction followed by acid precipitation and acid dissolution has been developed to produce highly purified nanosilica from pyrophyllite materials. The reaction parameters such as molar ratio NaOH/SiO2, reaction time and reaction temperature are varied for obtaining maximum nanosilica convertion. About 99,45% highly purified precipitated nanosilica measure with ICP, 259 m²/gr measure with BET surface area, 97% whiteness and 3 ml/gr oil absorbtion from pyrophyllite materials has been achieved in closed system at 150°C within 180 min. The physicals and chemical properties (such as X-Ray Diffraction from PANalytical, X-Ray Fluorescence Minipal4 from PANanalytical, BET surface area, Forier Transform Infra Red Spectroscopy from Hitachi, and SEM-EDS Inspect- S50 from FEI Company) of the highly purity nanosilica were studied. [ABSTRACT FROM AUTHOR]

A simple method based on alkaline extraction followed by acid precipitation and acid dissolution has been developed to produce highly purified nanosilica from pyrophyllite materials. The reaction parameters such as molar ratio NaOH/SiO2, reaction time and reaction temperature are varied for obtaining maximum nanosilica convertion. About 99,45% highly purified precipitated nanosilica measure with ICP, 259 m²/gr measure with BET surface area, 97% whiteness and 3 ml/gr oil absorbtion from pyrophyllite materials has been achieved in closed system at 150°C within 180 min. The physicals and chemical properties (such as X-Ray Diffraction from PANalytical, X-Ray Fluorescence Minipal4 from PANanalytical, BET surface area, Forier Transform Infra Red Spectroscopy from Hitachi, and SEM-EDS Inspect- S50 from FEI Company) of the highly purity nanosilica were studied. [ABSTRACT FROM AUTHOR]

Costly effective superhydrophobic glass surface by deposition of modified homemade pyrophyllite nanosilica has been done. The thin layer coating was deposited on glass substrate by means of spin coating technique with further thermal annealing process. SEM images show the different topography of the surface layers as well as nanosilica layer thickness in the range of 7 to 19 μm. The optimum water contact angle of 142.54° is obtained for the nanosilica coating annealed at 65°C. The presence of the CH, OH, Si-O-Si, and Si-C secondary phases is discussed based on FTIR data analysis. [ABSTRACT FROM AUTHOR]

The SA-Fe2.75Mn0.25O4/Ag ferrogel has been successfully synthesized using the encapsulsion method. The crystal structure characterization of the Fe2.75Mn0.25O4/Ag material was carried out using the XRD instrument. The XRD data analysis showed the appearance of peaks of the Fe3O4 phase and the Ag phase in the sample diffraction pattern. Furthermore, the characterization of the functional group SA-Fe2.75Mn0.25O4/Ag was conducted using the FTIR instrument which the results showed that the resulting functional group bonds correspond to the wavelength range of the constituent atoms. The magnetic properties of the SA-Fe2.75Mn0.25O4/Ag ferrogel were characterized using a YSM instrument. This characterization resulted in a hysteresis curve indicating that the magnetic properties of the SA-Fe2.75Mn0.25O4/Ag ferrogel behavior as superparamagnetic. Its potential application as a material in hyperthermia therapy is characterized by using a series of magnetic induction devices that produce optimal SAR (Specific Absorption Rate) values. The SAR values of ferrogel SA-Fe2.75Mn0.25O4/Ag at a frequency of 483 and 553 Hz were 0.12 and 0.24 W/g, respectively. [ABSTRACT FROM AUTHOR]

High salt-tolerant extracellular protease is an enzyme that plays a crucial role in industries and requires high salt conditions. Some protease enzymes are not resistant to high salt conditions because they may denature under high salt concentrations. Halophilic microbes produce extracellular enzymes that are stable at high salts. This research has succeeded isolating several halophilic microbes capable of producing extracellular proteases from Bledug Kuwu, Grobogan, Central Java, Indonesia. Extracellular proteases producing bacteria screened with skim milk selective medium and purified with the quadrant streak method. Then, the pure isolate and the resulting extracellular protease were characterized BK1B isolate was a Gram-positive bacterium, while BK1D was a Gram-negative bacterium. BK1B isolate is a halotolerant bacterium and BK1D is a moderate halophilic bacterium. BK1B and BK1D had the largest proteolytic index values, capable of producing extracellular proteases with an optimal production time of three days and pH 6. Extracellular proteases from BK1B and BK1D worked optimally at pH 6 and temperatures of 45 and 42 °C with 2.541 and 3.505 U/mL activity and resistance to NaCl concentrations ranging from 3 - 13% NaCl. This suggests that extracellular proteases from BK1B and BK1D strains can be stable at high salt concentrations. [ABSTRACT FROM AUTHOR]

An antineoplastic agent is one of the main focuses of pharmaceutical development to treat cancer disease. In silico study can efficiently reduce the time and cost of such screening anticancer agent candidates. This study aimed to screen the biological activity and pharmacological properties of potential Cyperus rotundus bioactive compounds. Five bioactive compounds contained in Cyperus rotundus, such as apigenin, aureusidin, luteolin, quercetin, and scaberin were used in this study. The biological activity of investigated bioactive compounds was analyzed using PASS (Prediction of Activity Spectra for Substances) software. SwissADME software was used to analyze the pharmacological properties of each compound. Results showed that various biological activities have a potential as anticancer of all investigated compounds including free radical scavenging, HIF-1a inhibitor, and apoptosis agonist activity. All investigated compounds except scaberin demonstrated an antimutagenic activity, TP53 enhancer, and MMP9 inhibitor. However, antineoplastic activity only showed by aureusidin, luteolin, and scaberin. Based on SwissADME analysis known that all investigated bioactive compounds showed optimum lipophilicity, size, polarity, solubility, and flexibility. But the only scaberin showed optimum saturation. Five bioactive compounds contained in Cyperus rotundus showed a promising effect as anticancer drug candidate, so it needs to be studied further. [ABSTRACT FROM AUTHOR]

This study aims to analyze Brantas River's quality through the Biotilik method by utilizing macrozoobenthos as a bioindicator. The study was conducted in January 2020. Determination of the sample location was done by purposive sampling. There were three sampling stations, namely in Coban Talun, Vinolia area, and Jodipan Tourism Village (KWJ) area. Data analysis of determining the Water Pollution Index (WPI) was done by calculating the macrozoobenthos tolerance index found at each station. The Water Pollution Index in Coban Talun is three so that it is clean and mildly polluted. The identified families are Tipulidae and Baetidae. The Water Pollution Index in the Vinolia Region and the KWJ Region is 2, indicating it as dirty and rather heavily polluted waters. The discovered families are Lymnaeidae, Thiaridae, Buccinidae, Parathelpusidae, Corbiculidae, and Chironomus. Vinolia Region and KWJ Region are close to the settlement. The closer to the settlement of the water quality tends to be polluted because the water contaminated by the waste from the human activities near the river. [ABSTRACT FROM AUTHOR]

Environmental pollution is a complex problem because waste is generated in all areas of life. If not handled properly, laboratory waste can pollute and endanger the environment. Laboratory waste containing heavy metals such as Cadmium, Chromium, Nickel, and Zinc is hazardous if it pollutes the environment. An easy and inexpensive method of treating heavy metal waste is adsorption. This research applies silica-cellulose material as heavy metal adsorbent in laboratory waste. Variations in contact time were used to measure the adsorbent capacity and adsorbent effectiveness on heavy metals Cadmium, Chromium, Nickel, and Zinc. The results showed that the contact time affected the adsorption capacity and the adsorption effectiveness of silica-cellulose on heavy metal content in laboratory waste. For Cd and Zn metals, the highest adsorption capacity at the contact time of 1 h with adsorption effectiveness values above 90%. Whereas for Cr and Ni metals, the highest adsorption capacity was at the contact time of 3 h with different values of adsorption effectiveness. For Cr metal, almost entirely can be absorbed well, while Ni metal is only half of the total metal can be absorbed. [ABSTRACT FROM AUTHOR]