Mini-Review Mengenai Pemanfaatan Material Berbasis Polimer Koordinasi Berpori untuk Penyimpanan Hidrogen

This review aims to summarize the various types of Metal-Organic Frameworks (MOFs) and their utilization for hydrogen storage. MOFs have high surface area, flexibility, good stability and tunability, various active sites, and abundant raw materials. These characteristics make MOFs worthy of being considered as a new material in hydrogen storage applications. The potential for using MOFs is very broad because its properties can be determined from the choice of metal and linker. Hydrogen gas storage commonly requires high pressure tanks whereas in liquid form, it requires cryogenic temperatures due to its very low boiling point, the challenge is to synthesize MOF with high hydrogen adsorption capacity under mild conditions. Moreover, it is crucial to learn about the relationship among the pore volume and surface area of MOFs, physisorption of hydrogen, and adsorption condition

PELATIHAN DAN PENDAMPINGAN PENERAPAN TEKNOLOGI SEL SURYA UNTUK PENGENTASAN MASALAH ELEKTRIFIKASI

ABSTRAKEnergi listrik merupakan kebutuhan dasar bagi masyarakat pada modern sekarang ini, dimana keberadaanya sangat mempengaruhi berbagai sendi kehidupan. Keterbasan dalam penyaluran energi listrik disebabkan oleh faktor geografis yang sulit dijangkau mempengaruhi peningkatan biaya investasi dalam pemasangan instalasi dan distribusi jaringan listrik. Tujuan dari pengabdian ini yaitu mengidentifikasi tingkat kebutuhan energi listrik dan memberikan sosialisasi serta penyuluhan kepada masyarakat mengenai Teknologi Tepat Guna (TTG) sel surya. Upaya yang dilakukan adalah dengan penerapan energi terbarukan melalui konversi sumber energi matahari menjadi energi listrik secara langsung yang merupakan solusi alternatif dalam pemenuhan kebutuhan energi listrik sehari-hari untuk daerah-daerah yang belum terjangkau jaringan listrik PLN. Metode yang digunakan untuk penerapan teknologi sel surya ini dilakukan melalui kegiatan pelatihan, penyuluhan dan pendampingan kepada masyarakat di sekitar Desa Muara Enggelam, Kabupaten Kutai Kartanegara. Hasil dan kegiatan ini menunjukkan bahwa masyarakat memperoleh wawasan dan kemampuan dalam mengoperasikan teknologi sel surya. Selain itu kegiatan ini juga menghasilkan prototipe Teknologi Tepat Guna (TTG) yang kompatibel, berdaya guna, dan mudah dioperasikan bagi pengguna listrik DC, AC dan gabungannya (DC+AC) untuk pemenuhan kebutuhan listrik sehari-hari. Penerapan jangka panjang dari prototipe TTG ini perlu dilakukan kajian, baik terkait kelayakan kinerja teknologi sel surya yang melibatkan banyak faktor maupun kajian kelayakan secara ekonomi terkait pembiayaan teknologi sel surya ini.           Kata kunci: : energi listrik; energi matahari; sel surya; prototipe TTG; kelayakan. ABSTRACTElectrical energy is a basic need for people in today's modern society, where its existence greatly affects various aspects of life. Limitations in the distribution of electrical energy caused by geographical factors that are difficult to reach affect the increase in investment costs in the installation and distribution of electricity networks. The purpose of this service is to identify the level of electrical energy needs and provide socialization and counseling to the community regarding appropriate technology (TTG) solar cells. The effort made is the application of renewable energy through the conversion of solar energy sources into electrical energy directly which is an alternative solution in meeting daily electrical energy needs for areas that have not been reached by the PLN electricity network. The method used for the application of solar cell technology is carried out through training, counseling and mentoring activities for the community around Muara Enggelam Village, Kutai Kartanegara Regency. The results and activities showed that the community gained insight and ability to operate solar cell technology. In addition, this activity also produced a prototype of Appropriate Technology (TTG) that is compatible, effective, and easy to operate for users of DC, AC and combined electricity (DC + AC) to fulfill their daily electricity needs. The long-term application of this TTG prototype needs to be studied, both related to the feasibility of solar cell technology performance involving many factors and economic feasibility studies related to the financing of this solar cell technology. Keywords: electrical energy; solar energy; solar cell; TTG prototype; feasibility

X-ray Absorption Near Edge Structure (XANES) Spectrum Interpretation for LiFePO4-Silicon Doped Cathode Material

LiFePO4-Silicon doped has been widely developed as a battery cathode material. Due to the doping of silicon atoms, this study aims to determine the peak energy (E0), oxidation state and percentage of component composition for Fe K-edge. The experimental sample used are LFP Si-0%, LFP Si-1%, LFP Si-3% and LFP Si-6%. These samples were characterized using XAS (X-ray Absorption Spectroscopy). XANES spectrum showed the peak energy of Pre-edge area is 7113.08 – 7114.49 eV. The oxidation state of Fe atoms were increased and tend to be Fe3+ than Fe2+. Moreover, Linear Combination Fitting (LCF) used to determine the ratio composition FeO/Fe2O3 in experimental samples. The ratio composition indicated Fe atom is multivalent, when the percentage of silicon-doped increases, the ratio of Fe3+ increased.It has been found that the presence of silicon atoms in the LiFePO4 structure has an effect in electronic structure

Analisis Pergerakan Partikel terhadap Rekaman Mikrotremor di Permukaan Sungai Bawah Tanah Bribin, Kawasan Karst Gunung Sewu

Microtremor has been widely used to determine soil characteristics and dynamics. In this research, particle motion analysis was conducted on 15 microtremor data recordings around the surface of the Bribin Underground River in the Gunungsewu Karst Area. Spectrum analysis was conducted as a basis for determining the frequency range for the particle motion analysis process. Particle motion analysis was only carried out on the horizontal component of the microtremor signal which is expected to provide a representation of the river flow path. The results of particle motion analysis of microtremor recordings in the surface area of the Bribin Underground River show that there are only two points that have a motion-resultant oriented to certain direction, which is perpendicular to the river channel.The points are A4 and B4 which are located in the eastern part of the river flow path

Oxidation state analysis of LiFeSixP1-xO4/C (x = 0.06) with X-ray absorption near edge structure (XANES) in Fe K-edge and Si K-edge

The development of LiFePO4 as a cathode materials on lithium-ion battery was increased with the use of additional techniques such as atomic doping and coating. The material used in this report was LiFeSi0.06P0.94O4/C (LFP Si-6%), synthesized with doping silicon 6% and 11wt% carbon coating by a solid state method. X-ray Absorption Spectroscopy (XAS) characterization was used to investigate the effect on electronic and atomic structure of LFP Si-6%, especially in X-ray Absorption Near Edge Strucuture (XANES) region. XANES data measured on Fe K-edge and Si K-edge. Fe foil, FeO, Fe2O3, FePO4, Si powder, SiO, SiO2 were used as a standard sample for comparison with the result of LFP Si-6%. XANES analysis showed that the energy absorption of Fe K-edge and Si K-edge in LFP Si-6% was 7124.94 eV and 1846.16 eV, respectively. The oxidation state of Fe was Fe2.576+ between Fe2+ and Fe3+, while Si was close to the estimation of Si4+. In addition, the linear combination fitting (LCF) in XANES Fe K-edge was performed to show the ratio of Fe2+/Fe3+ (FeO/Fe2O3)