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In this paper, we present the synthesis procedure and the results of an investigation of a novel silica xerogel (SX) glass ceramic developed from an amorphous SX derived from sago waste ash that incorporates TiO2 as an additive. The studied compositions have been prepared by adding of either 20% or 80 wt% of TiO2 into SX, respectively. The samples have been dry pressed and sintered in the temperature range between 900°C and 1500°C. Their properties have been characterized on the basis of the experimental data obtained using X-ray diffraction (XRD), Fourier transform infrared (FTIR), and ultraviolet-visible (UV-Vis) spectroscopy. It has been found that an increase of the content of SX in the composition leads to an increase of the shift of the bandgap energy of TiO2. The analysis based on the interpretation of both XRD patterns and FTIR spectrum allows one to explain the shift in the bandgap energy by an enlargement of the crystallite size of TiO2 and by forming of more Si–O–Ti bonds in the samples with a smaller loading of TiO2.

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A ceramic membrane has been produced from a natural zeolite. A series of samples has been sintered at range temperature from room temperaure to 900°C. The influence of the sintering temperature on the specific surface area, pore diameter, and surface roughness has been investigated. It has been found that a decrease for value of the specific surface area and average pore diameter from 300°C to 900°C was attributed to a change of the crystalline structure of tridimite from partially to fully crystallized samples. The fabricated membrane has been used successfully to evaluate the separation performance during the treatment of coconut sap. The membranes have a steady state flux from 0.12 to 0.22 mL/min.cm2 at an applied pressure of 1 bar.

Penelitian pembangkit listrik terus berkembang seiring meningkatnya kebutuhan energi listrik. Pemanfaatan sumber energi terbarukan seperti tenaga angin, tenaga air, tenaga gelombang laut serta tenaga arus laut memerlukan generator listrik putaran rendah tanpa eksitasi tambahan untuk dapat menghasilkan energi listrik. Generator sinkron magnet permanen (PMSG) merupakan generator yang medan eksitasinya dihasilkan oleh medan magnet permanen. Generator ini memiliki keunggulan dapat beroperasi pada putaran rendah serta tinggi memiliki tingkatan efisiensi yang lebih baik dibanding dengan generator induksi. Penggunaan PMSG bisa didapat dengan memanfaatkan motor BLDC mesin cuci bekas tipe satu tabung. Spesifikasi motor BLDC tipe outer rotor memiliki kumparan stator berbentuk roda gigi berinti besi berjumlah 36 coil dengan wiring 1 x 12 coil 3 fasa, terdiri 90 lilitan tiap coil dengan diameter penampang kawat 0,8 mm, berbahan alumunium dengan jenis belitan concentrated. Rotor memiliki 12 batang magnet permanen berbahan Barium ferrite (BaO 6Fe2O3). Secara konstruksi motor BLDC dan PMSG memiliki sebuah kemiripan dimana pada bagian rotornya terdapat magnet permanen, sehingga motor BLDC dapat dipertimbangkan untuk diaplikasikan sebagai generator. Hasil pengujian generator dari BLDC dapat membangkitkan daya listrik sebesar 855 VA pada kecepatan putar 1300 RPM, tegangan kerja generator sebesar 200 VAC fasa-netral, 350 VAC fasa-fasa dengan efisiensi sebesar 68,2 % .

The aim of this study is to investigate and analyze the NdFeB N52 type magnetic field distribution on a Trapezoidal type coil in an axial type generator. The main problems addressed by this study are how the distribution of magnetic field type NdFeB N52 to the trapezoidal type coil and how the influence of air gap between NdFeB N52 magnets and the coil to the output electric voltage generated from the coil at the speed of rotation. In order to answer the problems, we moved a rectangular type magnet axially towards the trapezoidal type coil with a specified distance, so that we could identify the change of the output voltage. The description of the magnetic field distribution in the stator was simulated by using the Maxwell 3D Design application ran in ANSYS software 16.0. The result of this study shows that the magnet was distributed evenly on the coil. It is also known that based on experiments with 2mm to 6mm of magnet to coils of gaps, the highest output voltage is at 2mm gaps at 750rpm.

This investigation presents the synthesis procedure and the results of an investigation of the crystallite growth of TiO 2 and the formation of Si-O-Ti bonds in novel silica xerogel (SiO 2 ) glass ceramic produced from an amorphous SX derived from sago waste ash. The composition had been prepared by adding various amounts of TiO 2 , from 20 wt% to 80 wt%, into the amorphous SiO 2 , and then a series of samples were sintered at 1200°C for 2 hours. The influence of the content of TiO 2 and the sintering temperature on the properties of TiO 2 , namely crystallite size and formation of Si-O-Ti bonds, has been studied in detail. The properties of the produced ceramics have been characterized on the basis of the experimental data obtained using X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. It has been found that an addition of SiO 2 confers an appreciable effect on the quantity of Si-O-Ti bonds. The interpretation of the XRD pattern allows one to explain the increase in the crystallite size of rutile TiO 2 by a decreased quantity of Si-O-Ti bonds.

The energy management strategy is the key to increasing the energy efficiency index (EEI) and controlling buildings' carbon emissions. This article discusses the energy policy strategy at Siliwangi University based on four main components of green campus: the profile of the electricity load, energy consumption, the rate of the number of vehicles, and vehicle activity in the campus environment. We propose four scenarios to meet the EEI and carbon emissions standards in 2025. The analysis of carbon emission production uses the UI Green Metric approach by referring to the carbon emission strategy from the Climate Action Tracker (CAT) and the profile of the world bank. Simultaneously, the EEI analysis uses the ASEAN-USAID standard, which is also used in the Indonesian National Standard (SNI). The conclusion is that even with the highest scenario to meet the target EEI level in 2025, Siliwangi University can only reach the EEI level in the "Extremely Efficient" category for the area with AC facilities and Extremely-Inefficient class for the area with AC facilities. The analysis results show that the most considerable contribution of carbon emissions is from motorbikes, 66%, cars and buses 33% and electricity use only 1.4%. Although the use of electricity does not have a significant emission impact, the EEI analysis results show a tendency towards electricity waste. Siliwangi University must immediately implement electric vehicles on campus to reduce carbon emissions from the mobility of motorbikes, cars, and buses.