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This study aimed to synthesize nanosized Mg0.2Fe2.8O4/AC/TiO2 composite for removal Pb(II) from water. The crystal structure and functional group of the sample were evaluated using XRD and FTIR spectroscopy. The morphology and band gap energy of the sample were characterized by means of SEM and UV-Vis spectroscopy. Meanwhile, the absorbance performance of the composite for removal Pb(II) was evaluated using AAS characterization. The results of the data analysis in this study showed that the Mg0.2Fe2.8O4/AC/TiO2 composite was successfully synthesized using coprecipitation method. The result of the XRD characterization presented the two phases for Mg0.2Fe2.8O4 and TiO2. The FTIR characterization results showed that the composite had a Fe-O bond at the tetrahedral and octahedral positions that were detected in the wavenumber range of 800–500 cm−1. The SEM image showed that the morphology of composite tended to agglomerate with a particle size distribution of 44.3 nm. The band gap energy resulting from the UV-Vis data analysis was 3.492 eV. Interestingly, the absorption efficiency for removal Pb(II) of the Mg0.2Fe2.8O4/AC/TiO2 composite reached 99.08%–99.90%. [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]

Fe3O4@SiO2 core-shell nanoparticles with variations of TEOS have been successfully fabricated by using polyol and sol-gel methods. The synthesized nanoparticles were characterized by using XRD, FTIR, SEM-EDX, and Magneto-thermal instruments to determine the nanostructure, functional groups absorption, morphological and thermal properties of the particles, respectively. The XRD data analysis results show that the greater the TEOS composition reduces the nanoparticle size distribution of the Fe3O4@SiO2 core-shell nanoparticles formed. This particle size distribution has been confirmed by SEM characterization, which reveals an average size of the Fe3O4@SiO2 core-shell nanoparticles of about 72.3 and 67.4 nm for the TEOS composition of 3 and 7 mL, respectively. The SiO2 composition also affects the thermal properties of the Fe3O4@SiO2 core-shell nanoparticles. The greater the SiO2 composition decreases the thermal temperature of the produced Fe3O4@SiO2 core-shell nanoparticles. This also affects the decreasing of the Specific Absorption Rate (SAR) of Fe3O4@SiO2 core-shell nanoparticles. Thus, the addition of the SiO2 composition can inhibit the distribution of the Fe3O4@SiO2 core-shell nanoparticles' thermal properties. [ABSTRACT FROM AUTHOR]

Zinc oxide nanorods/Graphene (ZnO NRs/Gr) were synthesized using an easy and fast method; spray for ZnO seed and graphene deposition and hydrothermal for ZnO NRs. The sample was varied by using different ZnO seed precursor of 0.1 M, 0.2 M, and 0.3 M. We found that the greater the concentration of ZnO led to a decrease in porosity, accompanied by an increase in the water contact angle of 150°, 153°, and 155°. The XRD results confirmed that there was no shift in the ZnO peak, which indicated that there was no significant structural change due to the lattice strain. UV-Vis analysis obtained a band gap of ∼3.4 eV and an excited state of ∼4 eV. Based on the results obtained, ZnO NRs/Graphene can be a promising waterproof coating material on cotton fabrics. [ABSTRACT FROM AUTHOR]

The curriculum of the State University of Malang (UM) uses life-based learning. The curriculum definition includes creativity, being able to integrate with everyday life, and learning without physical boundaries in the classroom. In line with the life-based curriculum, there is a learning model, namely ICARE (Introduction, Connect, Apply, Reflect, and Extend). The learning model is in line with the character of Introduction to Astrophysics and in-line with the curriculum designed by UM. The innovation needed in introductory Astrophysics learning that is in line with life-based learning is the ICARE stage, namely disseminating it. The products produced are modules, student worksheets, and student dissemination results. The development method is R&D (research and development). The development procedure used is to adapt the 4-D model (Define, Design, Develop, and Disseminate), but until the development stage. The results of the material and media experts related to learning devices were 3.00 or of good quality. Student responses to understanding the material strongly agree or with a score of 3.26. Student responses to the implementation of the ICARE + D learning model in the introductory astrophysics course strongly agree with an average score of 3.37. [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]