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Water electrolysis is decomposing water (H2O) into Oxygen and Hydrogen with the help of electric current. At present, the conventional electrolysis efficiency is around 50%. The use of catalysts is partly engineered to increase the... more
Water electrolysis is decomposing water (H2O) into Oxygen and Hydrogen with the help of electric current. At present, the conventional electrolysis efficiency is around 50%. The use of catalysts is partly engineered to increase the hydrogen production. In this paper, activated carbons from rice husk (RHAC) of 50 ppm and 100 ppm were added as the catalyst to increase Hydrogen production. FTIR tests showed that RHAC had an aromatic ring functional group with magnetic field. By the help of ImageJ software, it was proven that RHAC surface has an electric charge dominated by a positive charge. The magnetic field weakens the hydrogen bonding, while the electric charge increases the solution acidity, and makes it a good electrical conductor. As a result, greater addition of RHAC increases Hydrogen production. The largest hydrogen production of 8.2 ml for 10 minutes was obtained by the addition of 100 ppm.
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Dye-Sensitized Solar Cell (DSSC) in recent years have become widespread concern due to of their low production costs, abundant of the raw material reserves, simple of fabrication, and friendly to environment. Here, we provide the... more
Dye-Sensitized Solar Cell (DSSC) in recent years have become widespread concern due to of their low production costs, abundant of the raw material reserves, simple of fabrication, and friendly to environment. Here, we provide the performance of chlorophyll as natural green pigment for dye sensitizer in dye-sensitized solar cell. Density Functional Theory (DFT) computation and computation of Time Dependent Density Functional Theory (TD-DFT) was used to investigate UV-Vis absorption spectra, light harvesting efficiency (LHE), energy level, and electron injection efficiency (Oinject) which determine solar conversion efficiency. Using chlorophyll resulted in dye-sensitized solar cell that shown high potential requirement standard for light harvesting.
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There were two kinds of monsoon winds in Indonesia. They are the east and the west monsoon winds. Both of them blow alternately in a year through the Indonesian territory. The velocity and energy of monsoon winds in Indonesian territorial... more
There were two kinds of monsoon winds in Indonesia. They are the east and the west monsoon winds. Both of them blow alternately in a year through the Indonesian territory. The velocity and energy of monsoon winds in Indonesian territorial sea were mapped by using MatLab program. The velocity and energy data were obtained by using QuikSCAT satellite from January 1999 until December 2009, meanwhile WindSat from January 2004 until December 2014. The results show that high energy of monsoon winds start from Indian oceans until Nusa Tenggara sea, then from Arafuru sea to Banda sea, Java sea, Karimata strait and the southern region of south Sulawesi.
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Modified bamboo activated carbon (BAC) was added to non-edible Calophyllum inophyllum oil in a degumming process. The effects of its polarity and molecular dynamic energy on the degumming process were evaluated using characterizations and... more
Modified bamboo activated carbon (BAC) was added to non-edible Calophyllum inophyllum oil in a degumming process. The effects of its polarity and molecular dynamic energy on the degumming process were evaluated using characterizations and hyperChem software simulation. It was found that BAC acquired positive surface charge, polar characteristic, and mesoporous structures. The addition of BAC in the degumming process resulted in sufficient molecular dynamic energy (108.83 kcal/mol at 353K) as simulated by hyperChem, playing a role in facilitating successful dephospholipidation. Negatively charged oxygen around the hydrophilic phosphate head group of phospholipids was induced by BAC. The force exerted helped to loosen bonds around the polar head group. Interaction between BAC and polar water molecules also occurred, facilitating more hydrolysis reaction. These actions led to a higher possibility of phosphate head group removal off the phospholipid molecules. Consequently, there were large decreases in phosphorus, magnesium, and calcium concentrations along with small improvements in viscosity and calorific value in the degummed oil.
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Water is a chemical compound with chemical formula H2O. By the electrolysis proses, water can be split constituent elements, namely hydrogen (H2) and oxygen (O2). In this study, an electrolyze system used six pieces of electrodes which... more
Water is a chemical compound with chemical formula H2O. By the electrolysis proses, water can be split constituent elements, namely hydrogen (H2) and oxygen (O2). In this study, an electrolyze system used six pieces of electrodes which made from 304L SS for electrolysis process for both of distilled water and adding catalyst NaHCO3 (Sodium Bicarbonate) on distilled water. The results indicated that electrolysis process on distilled water consumed power of 353.52 Watts to produce Brown’s gas of 0.00123 l/s. Whenever, NaHCO3 was added into distilled water with the mass fraction of 1.33% consumed power decrease of 27.89 Watts and Browns gas was produced 0.0017 l/s. The efficiency of distilled water had the greatest efficiency only 5.53% by using current of 2 Ampere and power reached 31.043Watts. While the addition of catalysts had the greatest efficiency reached 40.29% in the use of mass fraction of catalyst 1.5%, 6 Ampere currents and power of 19.829 Watts.
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Research Interests: Engineering, Chemical Engineering, Materials Science, Chemistry, Energy, and 15 moreGraphene, Nanotechnology, Multidisciplinary, Optoelectronics, Nanocrystalline Material, Electron Transfer, Dye Sensitized Solar cell, Crystallinity, CHEMICAL SCIENCES, Carbazole, Langmuir, Electrolyte, Open Circuit Voltage, Linker, and Mesoporous Material
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Research Interests: Combustion and combustor
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Savonius windmill is ideal for areas that have low wind speeds and fluctuating. However, the weakness of Savonius windmill is the efficiency or better known as the coefficient of performance (Cp) is lower than horizontal axis wind turbine... more
Savonius windmill is ideal for areas that have low wind speeds and fluctuating. However, the weakness of Savonius windmill is the efficiency or better known as the coefficient of performance (Cp) is lower than horizontal axis wind turbine and Darrieus wind turbines. One cause is the formation of vortex when the blade was rotating. Vortex will absorb the energy of the wind flow or cause a negative kinetic energy. CFD simulation can be used as one tool that can be used to help analyze the loss of wind flow, including the formation of vortex on Savonius blades. Wind speed of 2 m/s and 5 m/s is used as a simulation variable to obtain an overview of wind flow losses occurring in blade Savonius. The largest vortex formed at an angle of 165 o rotating blade is good for wind speed of 2 m/s and 5 m/s. The larger the vortex area are formed causing the lower the pressure and torque acting on the blade surface.
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High humidity environments can accelerate the transmission, neutralization, or dissipation of frictional charges on the frictional surface of solid-solid triboelectric nanogenerator films (TENGs), which can reduce the output power. The... more
High humidity environments can accelerate the transmission, neutralization, or dissipation of frictional charges on the frictional surface of solid-solid triboelectric nanogenerator films (TENGs), which can reduce the output power. The moisture resistance properties of the TENG triboelectric film are needed to overcome these problems. Therefore, this study discusses the role of the TiO2 nanofiller in cassava starch (CS) and polyvinyl alcohol (PVA) nanocomposite matrix that can increase triboelectricity through the formation of hydrogen bonds and the provision of oxygen-free electrons. The research method was to incorporate different concentrations of TiO2 nanoparticles (0%, 0.5%, 1%, 5%, 10% wt, and 15% wt) into the CS-PVA nanocomposite matrix using the solvent casting method. The results showed an increase in surface polarity which was more triboelectric-positive due to the CS-PVA hydroxyl group interacting with water molecules. Increasing the concentration above 5% wt TiO2 increas...
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The utilization of biopolymers for energy applications continues to attract researchers, due to the unique properties of biopolymers that are easily modified, such as cassava starch (CS) biopolymer that has hydroxyl molecular chains.... more
The utilization of biopolymers for energy applications continues to attract researchers, due to the unique properties of biopolymers that are easily modified, such as cassava starch (CS) biopolymer that has hydroxyl molecular chains. However, the brittle, and non-waterproof nature of starch films is an obstacle to their use in triboelectric nanogenerator (TENG) solid-solid films. This study aims to improve the physicochemical properties of cassava starch films by modifying them into nanocomposite films. The nanocomposite film was made from 70:30 CS/polyvinyl alcohol (PVA) composite and variation of TiO2 nanoparticles addition using solvent casting method. The results showed that the mechanical properties of cassava starch film increased with the addition of PVA. Meanwhile, the addition of TiO2 above 1 wt % of the mechanical properties of the film tends to decrease. The film has low wettability properties with a contact angle of 83.6°. The performance of the nanocomposite film as a R...
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Abstrak Kincir Savonius merupakan salah satu jenis kincir yang mempunyai keunggulan desain dan konstruksi sederhana, torsi yang dihasilkan besar, dapat menerima angin dari segala arah dan dapat bekerja pada kecepatan angin rendah.... more
Abstrak Kincir Savonius merupakan salah satu jenis kincir yang mempunyai keunggulan desain dan konstruksi sederhana, torsi yang dihasilkan besar, dapat menerima angin dari segala arah dan dapat bekerja pada kecepatan angin rendah. Penambahan pengarah di sekeliling kincir bertujuan untuk meningkatkan koefisien daya dengan mengurangi torsi negatif pada sudu balik dan mengarahkan angin pada sudu dorong, disamping tetap dapat menerima angin dari segala arah. Pada tulisan ini akan disampaikan simulasi dengan menggunakan software ANSYS. Pengarah yang akan dianalisis dengan jumlah 4, 8 dan 16. Hasil yang diperoleh berupa distribusi tekanan pada kincir dan grafik torsi statik. Distribusi tekanan tertinggi terjadi pada saat posisi kincir membentuk sudut 90 0 terhadap arah angin pada masing-masing keadaan kecuali pada kincir dengan pengarah datar yang berjumlah 8 dan 16 terjadi pada posisi kincir membentuk sudut 135 0 . Torsi statik maksimum yang terjadi pada saat posisi kincir membentuk sudu...
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Harmful Algal Blooms (HABs), caused by Cochlodinium polykrikoides that causative fishery mortality, impact on aquaculture and economic loss appear particularly in summer and fall seasons in the Korean seas. It was studied on... more
Harmful Algal Blooms (HABs), caused by Cochlodinium polykrikoides that causative fishery mortality, impact on aquaculture and economic loss appear particularly in summer and fall seasons in the Korean seas. It was studied on characteristics of HABs in the South Sea of Korea by using satellite and in-situ data. The in-situ data encompassed oceanic and meteorological data from July to October 2002-2008 and satellite data from July to October 2002-2006. Chlorophyll concentrations were calculated using Seaviewing Wide Field-of-view Sensor images by an Ocean Color (OC4) algorithm, and HABs were estimated using the Red tide index Chlorophyll Algorithm (RCA). The HAB occurrences were dominant when water temperature was in August. The frequency of the individual numbers during 2002-2008, the HABs more than 1000 cells/ml (alert condition), were 73.57 %. In meteorological data from July to September during 2002-2008, the average precipitation, the mean air temperature, the mean wind speed and...
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This study aims to determine the effect of the protective gas flow rate on the tensile and shock strength of welded joints of dissimilar metals, namely aluminum 5052 – galvanized steel with Al-Si 4043 filler using argon gas as a shielding... more
This study aims to determine the effect of the protective gas flow rate on the tensile and shock strength of welded joints of dissimilar metals, namely aluminum 5052 – galvanized steel with Al-Si 4043 filler using argon gas as a shielding gas. The protective gas flow rate parameters used in this study were 14, 17, and 20 liters/minute with a current of 80 A. The results showed that the higher the flow rate of the shielding gas, the lower the porosity defects that occurred in the welding results, resulting in higher tensile and shock strength values. Based on the analysis through the results of penetrant testing, it shows that the addition of the protective gas flow rate is given to reduce the porosity defects in the welding area. The surface area experiencing porosity decreases with the addition of the protective gas flow rate of 14, 17, and 20 liters/minute of 59.748%, 50.918%, and 48.857% respectively. The highest tensile strength was obtained from welding with a protective gas fl...
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Modified bamboo activated carbon (BAC) was added to non-edible Calophyllum inophyllum oil in a degumming process. The effects of its polarity and molecular dynamic energy on the degumming process were evaluated using characterizations and... more
Modified bamboo activated carbon (BAC) was added to non-edible Calophyllum inophyllum oil in a degumming process. The effects of its polarity and molecular dynamic energy on the degumming process were evaluated using characterizations and hyperChem software simulation. It was found that BAC acquired positive surface charge, polar characteristic, and mesoporous structures. The addition of BAC in the degumming process resulted in sufficient molecular dynamic energy (108.83 kcal/mol at 353K) as simulated by hyperChem, playing a role in facilitating successful dephospholipidation. Negatively charged oxygen around the hydrophilic phosphate head group of phospholipids was induced by BAC. The force exerted helped to loosen bonds around the polar head group. Interaction between BAC and polar water molecules also occurred, facilitating more hydrolysis reaction. These actions led to a higher possibility of phosphate head group removal off the phospholipid molecules. Consequently, there were l...
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Pusat Prestasi Nasional (Puspresnas) bertugas untuk menyiapkan kebijakan teknis, melaksanakan, memantau, mengevaluasi, dan melaporkan berbagai program di bidang pengembangan prestasi satuan pendidikan. Salah satu program yang berkaitan... more
Pusat Prestasi Nasional (Puspresnas) bertugas untuk menyiapkan kebijakan teknis, melaksanakan, memantau, mengevaluasi, dan melaporkan berbagai program di bidang pengembangan prestasi satuan pendidikan. Salah satu program yang berkaitan dengan tugas tersebut adalah Kontes Mobil Hemat Energi atau disebut dengan KMHE. Pedoman Kontes Mobil Hemat Energi Tahun 2021 di bawah koordinasi Puspresnas, Sekretariat Jenderal Kementerian Pendidikan dan Kebudayaan, ini dapat disosialisasikan,dipahami, diterapkan, serta dievaluasi untuk mendapatkan umpan balik dalam rangka peningkatan program yang bermutu dan berkelanjuta
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Organic metal halide perovskite has recently shown great potential for applications, as it has the advantages of low cost, excellent photoelectric properties, and high power conversion efficiency. The Hole Transport Material (HTM) is one... more
Organic metal halide perovskite has recently shown great potential for applications, as it has the advantages of low cost, excellent photoelectric properties, and high power conversion efficiency. The Hole Transport Material (HTM) is one of the most critical components in Perovskite Solar Cells (PSC). It has the function of optimizing the interface, adjusting the energy compatibility, and obtaining higher PCE. The inorganic p-type semiconductor is an alternative HTM due to its chemical stability, higher mobility, increased transparency in the visible region, and general valence band energy level (VB). Here we report the use of the Graphene Oxide (GO) layer as a Hole Transport Layer (HTL) to improve the perovskite solar cells' performance. The crystal structure and thickness of GO significantly affect the increase in solar cell efficiency. This perovskite film must show a high degree of crystallinity. The configuration of the perovskite material is FTO/NiO/GO/CH3NH3PbI3/ZnO/Ag. G...