Mahreni Mahreni - Academia.edu (original) (raw)
Papers by Mahreni Mahreni
Indonesian journal on geoscience, Jan 8, 2023
The magma evolution of Ngebel Volcano, both temporally and spatially, is represented by the chara... more The magma evolution of Ngebel Volcano, both temporally and spatially, is represented by the characteristics of its lava. Ngebel Volcano, located in East Java, is a Quaternary andesitic stratovolcano. This volcano is part of the Wilis Volcanic Complex. The volcanism stage of Ngebel Volcanic Complex can be divided into the Jeding with andesitic basalt (SiO 2 49-59%), pyroxene andesite Kemlandingan (SiO 2 49-59%), Manyutan with hornblende andesite (SiO 2 49-59%), and Ngebel with dacite (SiO 2 : 49-59%). The variation of major elements combined with petrographic features such as plagioclase, pyroxene, hornblende, quartz, and opaque minerals from basaltic andesite to dacite is interesting. The minerals show that the magma differentiation process of Ngebel Volcanic Complex is the results of fractional crystallization of magma. The purpose of this study is to determine the evolution of magma from volcanic rocks of which stratigraphic positions have been determined. The analytical methodology used is petrographic and geochemical analysis. Detailed temporal evolution shows that magma from the Ngebel Volcanic Complex underwent a differentiation process that changed the magma composition from mafic to more felsic.
MATEC Web of Conferences
Energy is a need of society and industry which is increasing every year. However, the world's... more Energy is a need of society and industry which is increasing every year. However, the world's oil reserves continue to run low, so the development of renewable alternative energy is needed. One of the new renewable energies that can be developed is vegetable fuel or biofuel. Biodiesel which is a type of biofuel is being widely produced recently. The cetane number determines the quality of biodiesel. Solketal is an additive added to biodiesel to increase the cetane number. The ketonation reaction was used in this study to obtain the solketal. In the manufacture of solketal a catalyst is needed to speed up the reaction and increase conversion. Phosphotungstic Woifram Acid (PWA) is a heterogeneous catalyst chosen because it can be separated from solution. Based on the results of the study, the optimal time for making solketal was 4 hours and the highest solketal conversion was at a reaction temperature of 60oC with a constant reactant mole ratio of 1:3:1 and a percentage of 2% cata...
Indonesian Journal of Materials Science, Oct 1, 2010
Hydrogen fuel cells proton exchangemembrane fuel cell (PEMFC) is currently still in development a... more Hydrogen fuel cells proton exchangemembrane fuel cell (PEMFC) is currently still in development and commercialization. Several barriers to the commercialization of these Nafion membrane as electrolyte is its very sensitive to humidity fluctuation. Nafion must be modified by making a composite Nafion-SiO 2 -HPA to increase electrolyte resistance against humidity fluctuations during the cell used. Research carried out by mixing Nafion solution with Tetra Ethoxy Ortho Silicate (TEOS) and conductive materials is phosphotungstic acid (PWA) by varying the ratio of Nafion, TEOS and PWA. The membrane is produced by heating a mixture of Nafion, TEOS and PWA by varying the evaporation temperature, time and annealing temperature to obtain the transparentmembrane. The resultingmembrane was analyzed its physical, chemical and electrochemical properties by applying the membrane as electrolyte of PEMFC at various humidity and temperature of operation. The results showed that at low temperatures (30-90) °C and high humidity at 100 %RH, pure Nafion membrane is better than composite membrane (Nafion-SiO 2 -PWA), but at low humidity condition composite membrane is better than the pure Nafion membrane. It can be concluded that the compositemembranes of (Nafion-SiO 2 -PWA) can be used as electrolyte of PEMFC operated at low humidity (40 %RH) and temperature between (30-90) °C. Keywords: Membrane, Nanocomposite, Nafion-SiO 2 -PWA, PEMFC, Humidity.
RSF Conference Series: Engineering and Technology, 2021
Plastic waste has become a global problem because it causes environmental pollution. This is beca... more Plastic waste has become a global problem because it causes environmental pollution. This is because plastic waste is difficult to decompose. There have been numerous solutions proposed, one of which is theuse of bioplastics. In this research, the bioplastics were made from third- generation biomass, namely the eucheuma cottoni. Eucheuma cottoni is contains biopolymer carrageenan, a carbohydrate with unit structures consisting of d-galactose and 3,6 anhydrogalactose with glycosidic bonds. Goal this research is study the effects of sorbitol plasticizer content and bioplastics manufacturing temperature on bioplastics, tensile strength, elongation, and biodegradation rate. The bioplastics were made by extracting 10 grams of eucheuma cottoni powder in 200 ml of distilled water. The algae extract was added with sorbitol (plasticizer) and heated at various temperatures from 45°C until 60°C. The mixture was poured into a mold tin and dried in the oven to a constant weight. The resulting bi...
THE 2ND INTERNATIONAL SYMPOSIUM OF INDONESIAN CHEMICAL ENGINEERING 2021: Enhancing Innovations and Applications of Chemical Engineering for Accelerating Sustainable Development Goals
Biodegradable adhesives are essential to be developed to replace synthetic adhesives. This resear... more Biodegradable adhesives are essential to be developed to replace synthetic adhesives. This research aims to study the effects of α-amylase enzyme concentration on the process of making adhesives from glutinous rice flour dextrin by examining the ratio of dextrin: CMC: glycerin on glue adhesion. This research was conducted in two stages: the making of dextrin from glutinous rice flour, and then the making of glue from the dextrin. The dextrin was made by mixing glutinous rice flour with water with a concentration of 200 grams/600 mL, then adding the α-amylase enzyme with variations (2 mL, 4 mL, 6 mL, 8 mL, 10 mL) and heated to a temperature of 80oC for 30 minutes, while continuously stirred at 300 rpm. After that, the liquid dextrin was filtered, and then the wet dextrin flour was dried in the sun to a constant weight. The dextrin was then sieved using a 200-mesh sieve. The dextrin was mixed with CMC and glycerin in a specific ratio, then heated to a temperature of 85oC for 20 minutes, and cooled to produce glue. The resulting glue was tested for adhesion. The adhesive strength test was carried out on a paperboard measuring 2.5 cm x 15 cm and 1.15-mm thick. This study found that the weight ratio of dextrin: CMC: glycerin affected the glue adhesion. The best glue adhesion was obtained at the weight ratio of dextrin: CMC: glycerin of 10 grams: 4 grams: 2.1 grams with adhesion of 171.4 N. The highest adhesion was 171.4 N which was better than standard paper glue sold in the market with the adhesion of 65.5 N.
RSF Conference Series: Engineering and Technology, 2021
The Ngebel geothermal area is morphologically in several volcanic cones arranged as lava domes, v... more The Ngebel geothermal area is morphologically in several volcanic cones arranged as lava domes, volcanic hills, and lake craters. Volcanic cones are composed of lava, pyroclastic falls, pyroclastic flows, volcanic cones such as Jeding Volcano, Kemlandingan Volcano, Manyutan Volcano, and Ngebel Volcano. The magmatism activity that occurs in this area is andesitic-dacitic and also forms a geothermal system. This geothermal system is estimated to produce 50 MWe. During the formation of a geothermal system, hydrothermal fluids interact with the surrounding rock. Based on the results of geological mapping, petrographic analysis, and analysis of rare earth elements. In general, the results of rock-fluid interactions show a decrease in the concentration of rare earth elements, both light and heavy REE elements, from andesite basaltic samples to cold water samples. However, an unexpected reduction from 10 times chondrite to 0.3 times chondrite from hot water to cold water. This research wil...
Advanced Materials Research, 2011
Abstract Polymer electrolyte membrane based on Nafion and zirconium oxide (ZrO 2) was developed v... more Abstract Polymer electrolyte membrane based on Nafion and zirconium oxide (ZrO 2) was developed via film casting method. The content of ZrO 2 (1.0, 2.0, and 3.0 wt.%) was incorporated with Nafion solution to prepare Nafion-ZrO 2 composite membranes. Recast ...
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Alga coklat (Phaeophyta) mengandung senyawa aktif seperti karbohidrat, protein, phenolik, lemak, ... more Alga coklat (Phaeophyta) mengandung senyawa aktif seperti karbohidrat, protein, phenolik, lemak, pigmen, vitamin dan mineral. Kandungan mineral alga coklat sekitar 8-40 % terdiri atas kation Na + , K + , Mg ++ , Fe ++ , Zn ++ , Mn ++ dan logam berat. Bioaktif alga coklat memiliki banyak manfaat, salah satunya adalah Fucoidan sebagai obat kanker. Hambatan pemanfaatan Fucoidan sebagai obat adalah kandungan mineral yang tinggi sehingga mineral tersebut harus dipisahkan. Proses ekstraksi alga coklat menggunakan berbagai metode telah dilakukan dengan tujuan mengisolasi komponen aktif Fucoidan yang bebas dari mineral yang akan menjadi hambatan dalam memanfaatkan komponen aktif. Dalam makalah ini akan diuraikan beberapa metode terbaru ekstraksi bahan aktif alga coklat dan proses pemisahan mineral menggunakan membran Mikro Filtrasi (MF) dan Ultra Filtrasi (UF). Membran MF dan UF dapat memisahkan molekul kecil seperti kation (mineral) dapat lolos melalui membran sehingga makromolekul seperti karbohidrat, lemak, protein, pigmen, phenolic dan vitamin dapat terpisah dari mineral dan diperoleh bahan aktif tanpa adanya mineral. Tujuan dari makalah ini adalah memberikan arah penelitian dalam eksplorasi bahan aktif alga coklat untuk aplikasi farmasi dan kosmetik tanpa efek samping yang disebabkan oleh kandungan logam atau mineral yang tinggi di atas nilai ambang batas di dalam ekstrak alga coklat.
Prosiding Seminar Nasional LPPM, Nov 25, 2021
Covid 19 is a highly contagious respiratory disease caused by the new corona virus. Covid 19 was ... more Covid 19 is a highly contagious respiratory disease caused by the new corona virus. Covid 19 was first discovered in Indonesia in March 2020 and significantly increase. Covid 19 has resulted in restrictions on various social activities, the implementation of the school system and working from home to the closure of tourist attractions and shopping centers, etc. As a result, Indonesia's economy is getting worse. Spraying disinfectants at homes and public facilities is one way to prevent the spread of the corona virus. The purpose of this activity is to provide counseling on how to make disinfectants to break the chain of spread of the corona virus. This activity was carried out in June 2021 which was attended by representatives of several members of the PRTB youth group in Gagaksipat village, Ngemplak, Boyolali. This PKM activity was carried out using several methods, including the lecture method when delivering material about how to make disinfectants, the practical method of making disinfectants and spraying disinfectants into people's homes. This service activity was well received by the participants because after the counseling was carried out, members of the youth group (PRTB) could make disinfectant and apply it for spraying color houses.
Abstrak PRODUKSI BATIK RAMAH LINGKUNGAN DI DUSUN KALIAJIR KIDUL KELURAHAN KALITIRTO,KECAMATAN BER... more Abstrak PRODUKSI BATIK RAMAH LINGKUNGAN DI DUSUN KALIAJIR KIDUL KELURAHAN KALITIRTO,KECAMATAN BERBAH, SLEMAN DAERAH ISTIMEWA YOGYAKARTA Mahreni, Wasir Nuri, Tutik Muji Setyoningrum The natural dye now growing rapidly along with public awareness to induce negative impact of the batic industry. Wealness of batural dye is unstable. Research and development to produce a stable natural dye is still underway. Particullary natural dye to use as a textile and batik dye. Producing batik uses batural dye is more difficult than to produce synthetic dte. So the price is more . expensive. Barrier constranint need to have to find a way out. In this study attempt to use a ne technology that uses technique stamp in order to save time in producing batik The purpos of this study was to produce batik using blue colour of the plant Indigofera tinctoria,the brown colour of the fruit plants Jolawe, brown colour of Mahoni ang green colour of the micture of Indigo and Jo;awe. The result showed that the col...
The eggs produce waste in the form of eggs shell. One alternative to reduce the waste is by proce... more The eggs produce waste in the form of eggs shell. One alternative to reduce the waste is by processin g the egg shell into hydroxy apatite powder. Eggshell is one of the largest sources of calcium carbonate , with 95% of composition. The characteristics of hy droxy apatites that allowed to be used as biomateri als including the mass ratio of Ca:P should have a valu e of 1.67 and have a crystalline structure. In the first step, the eggs shell reacted with hydrochloric acid . Solution formed to the base condition to get the calcium deposits, which then reacted with sodium ph osphate to produce hydroxy apatite deposition. The deposition which formed then dried and heated for f orming the hydroxy apatite crystals. The hydroxy apatite crystals are analyzed by X-Ray Difractometr y (XRD) and Energy Dispersive Spectroscopy X-ray (EDS). From the analysis results, the mass ratio of Ca:P respectively for samples A (0.8 gr CaCO 3 1 mol 20ml HCl and 0.3 mol Na 3PO 4), C (0.8 gr CaCO 3 1 mol 20ml...
Membran komposit telah digunakan dalam proses pemisahan komponen untuk menghasilkan komponen tule... more Membran komposit telah digunakan dalam proses pemisahan komponen untuk menghasilkan komponen tulen dan sebagai elektrolit. Membran nafion sebagai elektrolit dalam sel fuel membrane penukar ion atau Proton Exchange Membrane Fuel Cell (PEMFC) mempunyai kelemahan yaitu konduktiviti Proton dan prestasi selnya akan turun apabila kandungan air di dalam air akan menurun. Bagi mengatasi masalah tersebut, kajian dengan cara menambahkan komponen yang bersifat hidrokofis dan kondukviti tinggi ke dalam kluster polimer nafion telah dilaksanakan. Kajian ini adalah untuk menghasilkan membran nanokomposit campuran nafion-SiO2-PWA menggunakan kaedah sol-gel fasa larutan. Antara parameter yang dikaji adalah suhu penyejatan pelarut, suhu dan waktu penyepuhlindapan dan nisbah TEOS/nafion. Kajian penentuan sifat membran yang dihasilkan adalah morfologi, sifat termal, struktur kimia terbentuk, kandungan kimia, dan kejernihan membran. Prestasi membran komposit sebagai elektrolit dilakukan dengan menggunak...
Penelitian ekstraksi kurkumin dari kunyit dengan pelarut etanol telah dilakukan dalam kolom yang ... more Penelitian ekstraksi kurkumin dari kunyit dengan pelarut etanol telah dilakukan dalam kolom yang diisi dengan kunyit sebagai unggun tetap dan pelarut mengalir secara kontinyu dari atas kolom. Kurkumin yang terekstrak dari kunyit dianalisa setiap waktu tertentu dengan mengukur indek biasnya dengan menggunakan alat Refraktometer. Pengamatan dihentikan setelah konsentrasi kurkumin di dalam pelarut tetap. Penelitianini dilakukan untuk menentukan model perpindahan massa padat-cair dengan mengamati variable kecepatan aliran pelarut, diameter kolom, dan tinggi unggun. Model matematis disusun berdasarkan neraca massa kurkumin yang bergerak dari dalam padatan ke permukaan kemudian mendifusi ke dalam aliran pelarut yang bergerak dari atas ke bawah kolom dapat dinyatakan dengan persamaan sebagai berikut :D_AB (d^2 CA)/(dZ^2 )+V (dCA)/dZ+KCA (HXA-CA)=∈(dCA)/dt; (dXA)/dt=-KCA/ρB (CA*-CA).Penyelesaian persamaan diatas dengan cara eksplisit dan optimasi didapatkan harga KCA yang diperoleh antara 0...
Nafion-Silica oxide (SiO2)-Phosphotungstic acid (PWA) composite membrane have been synthesized us... more Nafion-Silica oxide (SiO2)-Phosphotungstic acid (PWA) composite membrane have been synthesized using solution phase sol-gel method. The effect of the weight ratio of Nafion:SiO2:PWA to the electrochemical properties of composite membrane when applies as electrolyte in the PEMFC was investigated using Fuel Cell Test System (FCTS) at temperature of range of 80 – 90 oC and 40% relative humidity (RH). The weight ratio of the composite membrane samples varied in the range of 100:2.88:1.15, 100:4.33:1.73 and 100:5.76:2.30 and designated as NS10W, NS15W and NS20W, respectively. The aim of the experiment was to insert the inorganic hygroscopic and high conductivity filler like PWA and SiO2 in the Nafion matrix to order to improve the water retention, proton conductivity (σ), hydrogen crossover (β), and thermal stability in addition to increase PEMFC performance at elevated temperature and low RH condition. The result showed when appropriately embeded in the Nafion cluster, the hydrated PWA ...
NANOCOMPOSITE ELECTROLYTE MEMBRANE FOR MODERATE TEMPERATURE AND LOW RELATIVE HUMIDITY HYDROGEN PR... more NANOCOMPOSITE ELECTROLYTE MEMBRANE FOR MODERATE TEMPERATURE AND LOW RELATIVE HUMIDITY HYDROGEN PROTON EXCHANGE MEMBRANE FUEL CELL (HPEMFC) APPLICATlON Mahreni, A.B. Mohamad, A.A.H. Kadhum, W.R.W. Daud Department of Chemical Engineering -Faculty of Technology Industry- University Pembangunan Nasional Yogyakarta-Indonesia Institute of Fuel Cell- Universiti Kebangsaan Bangi - Malaysia 43600 Nowadays PEMFC with hydrogen fuel has developed to commercialize to replace the conventional machine. Several limitations in PEMFC commercialization are its low efficiency, viability of hydrogen fuel supply and problem of controlling fuel and water as reaction products. Effective effort to increase efficiency and water management include elevating temperature of PEMFC operation near water boiling point to increase energy produced, prevent water flooding, enhanced cooling efficiency and also the possibility to use hydrogen and air under lower humidity in order to make simples PEMFC design. But at ele...
Waste of chemical laboratory without dilution was analyzed and it was found that pH = 5.5 while (... more Waste of chemical laboratory without dilution was analyzed and it was found that pH = 5.5 while (COD=171 717 mg/L) and BOD = 10500.1 mg/L) . This research carried out to reduce COD and BOD using flocculation and coagulation processes. Research has been done by mixing the waste with Alum in a flask equipped with a stirrer. Waste is stirred for 15 minutes at a constant speed of 150 rpm. After that the pH of the waste is increased by adding Calcium hydroxide Ca(OH)2 so as to achieve a certain pH. The addition of alum and Ca(OH)2 caused the formation of flock. The flock formed more and more, and left without stirring for 24 hours for maximum flock formation. Further separation of flock using a filter. The COD-BOD of the supernatant is analized. The purpose of the study to determine the pH and the ratio of alum:waste to the reduction of are greatly affect the reduction of COD/BOD. Reduction of COD/BOD highest achieved at pH 12.2 and the ratio of alum/waste is 1/0 (ml/ml) ( COD reduction ...
Indonesian journal on geoscience, Jan 8, 2023
The magma evolution of Ngebel Volcano, both temporally and spatially, is represented by the chara... more The magma evolution of Ngebel Volcano, both temporally and spatially, is represented by the characteristics of its lava. Ngebel Volcano, located in East Java, is a Quaternary andesitic stratovolcano. This volcano is part of the Wilis Volcanic Complex. The volcanism stage of Ngebel Volcanic Complex can be divided into the Jeding with andesitic basalt (SiO 2 49-59%), pyroxene andesite Kemlandingan (SiO 2 49-59%), Manyutan with hornblende andesite (SiO 2 49-59%), and Ngebel with dacite (SiO 2 : 49-59%). The variation of major elements combined with petrographic features such as plagioclase, pyroxene, hornblende, quartz, and opaque minerals from basaltic andesite to dacite is interesting. The minerals show that the magma differentiation process of Ngebel Volcanic Complex is the results of fractional crystallization of magma. The purpose of this study is to determine the evolution of magma from volcanic rocks of which stratigraphic positions have been determined. The analytical methodology used is petrographic and geochemical analysis. Detailed temporal evolution shows that magma from the Ngebel Volcanic Complex underwent a differentiation process that changed the magma composition from mafic to more felsic.
MATEC Web of Conferences
Energy is a need of society and industry which is increasing every year. However, the world's... more Energy is a need of society and industry which is increasing every year. However, the world's oil reserves continue to run low, so the development of renewable alternative energy is needed. One of the new renewable energies that can be developed is vegetable fuel or biofuel. Biodiesel which is a type of biofuel is being widely produced recently. The cetane number determines the quality of biodiesel. Solketal is an additive added to biodiesel to increase the cetane number. The ketonation reaction was used in this study to obtain the solketal. In the manufacture of solketal a catalyst is needed to speed up the reaction and increase conversion. Phosphotungstic Woifram Acid (PWA) is a heterogeneous catalyst chosen because it can be separated from solution. Based on the results of the study, the optimal time for making solketal was 4 hours and the highest solketal conversion was at a reaction temperature of 60oC with a constant reactant mole ratio of 1:3:1 and a percentage of 2% cata...
Indonesian Journal of Materials Science, Oct 1, 2010
Hydrogen fuel cells proton exchangemembrane fuel cell (PEMFC) is currently still in development a... more Hydrogen fuel cells proton exchangemembrane fuel cell (PEMFC) is currently still in development and commercialization. Several barriers to the commercialization of these Nafion membrane as electrolyte is its very sensitive to humidity fluctuation. Nafion must be modified by making a composite Nafion-SiO 2 -HPA to increase electrolyte resistance against humidity fluctuations during the cell used. Research carried out by mixing Nafion solution with Tetra Ethoxy Ortho Silicate (TEOS) and conductive materials is phosphotungstic acid (PWA) by varying the ratio of Nafion, TEOS and PWA. The membrane is produced by heating a mixture of Nafion, TEOS and PWA by varying the evaporation temperature, time and annealing temperature to obtain the transparentmembrane. The resultingmembrane was analyzed its physical, chemical and electrochemical properties by applying the membrane as electrolyte of PEMFC at various humidity and temperature of operation. The results showed that at low temperatures (30-90) °C and high humidity at 100 %RH, pure Nafion membrane is better than composite membrane (Nafion-SiO 2 -PWA), but at low humidity condition composite membrane is better than the pure Nafion membrane. It can be concluded that the compositemembranes of (Nafion-SiO 2 -PWA) can be used as electrolyte of PEMFC operated at low humidity (40 %RH) and temperature between (30-90) °C. Keywords: Membrane, Nanocomposite, Nafion-SiO 2 -PWA, PEMFC, Humidity.
RSF Conference Series: Engineering and Technology, 2021
Plastic waste has become a global problem because it causes environmental pollution. This is beca... more Plastic waste has become a global problem because it causes environmental pollution. This is because plastic waste is difficult to decompose. There have been numerous solutions proposed, one of which is theuse of bioplastics. In this research, the bioplastics were made from third- generation biomass, namely the eucheuma cottoni. Eucheuma cottoni is contains biopolymer carrageenan, a carbohydrate with unit structures consisting of d-galactose and 3,6 anhydrogalactose with glycosidic bonds. Goal this research is study the effects of sorbitol plasticizer content and bioplastics manufacturing temperature on bioplastics, tensile strength, elongation, and biodegradation rate. The bioplastics were made by extracting 10 grams of eucheuma cottoni powder in 200 ml of distilled water. The algae extract was added with sorbitol (plasticizer) and heated at various temperatures from 45°C until 60°C. The mixture was poured into a mold tin and dried in the oven to a constant weight. The resulting bi...
THE 2ND INTERNATIONAL SYMPOSIUM OF INDONESIAN CHEMICAL ENGINEERING 2021: Enhancing Innovations and Applications of Chemical Engineering for Accelerating Sustainable Development Goals
Biodegradable adhesives are essential to be developed to replace synthetic adhesives. This resear... more Biodegradable adhesives are essential to be developed to replace synthetic adhesives. This research aims to study the effects of α-amylase enzyme concentration on the process of making adhesives from glutinous rice flour dextrin by examining the ratio of dextrin: CMC: glycerin on glue adhesion. This research was conducted in two stages: the making of dextrin from glutinous rice flour, and then the making of glue from the dextrin. The dextrin was made by mixing glutinous rice flour with water with a concentration of 200 grams/600 mL, then adding the α-amylase enzyme with variations (2 mL, 4 mL, 6 mL, 8 mL, 10 mL) and heated to a temperature of 80oC for 30 minutes, while continuously stirred at 300 rpm. After that, the liquid dextrin was filtered, and then the wet dextrin flour was dried in the sun to a constant weight. The dextrin was then sieved using a 200-mesh sieve. The dextrin was mixed with CMC and glycerin in a specific ratio, then heated to a temperature of 85oC for 20 minutes, and cooled to produce glue. The resulting glue was tested for adhesion. The adhesive strength test was carried out on a paperboard measuring 2.5 cm x 15 cm and 1.15-mm thick. This study found that the weight ratio of dextrin: CMC: glycerin affected the glue adhesion. The best glue adhesion was obtained at the weight ratio of dextrin: CMC: glycerin of 10 grams: 4 grams: 2.1 grams with adhesion of 171.4 N. The highest adhesion was 171.4 N which was better than standard paper glue sold in the market with the adhesion of 65.5 N.
RSF Conference Series: Engineering and Technology, 2021
The Ngebel geothermal area is morphologically in several volcanic cones arranged as lava domes, v... more The Ngebel geothermal area is morphologically in several volcanic cones arranged as lava domes, volcanic hills, and lake craters. Volcanic cones are composed of lava, pyroclastic falls, pyroclastic flows, volcanic cones such as Jeding Volcano, Kemlandingan Volcano, Manyutan Volcano, and Ngebel Volcano. The magmatism activity that occurs in this area is andesitic-dacitic and also forms a geothermal system. This geothermal system is estimated to produce 50 MWe. During the formation of a geothermal system, hydrothermal fluids interact with the surrounding rock. Based on the results of geological mapping, petrographic analysis, and analysis of rare earth elements. In general, the results of rock-fluid interactions show a decrease in the concentration of rare earth elements, both light and heavy REE elements, from andesite basaltic samples to cold water samples. However, an unexpected reduction from 10 times chondrite to 0.3 times chondrite from hot water to cold water. This research wil...
Advanced Materials Research, 2011
Abstract Polymer electrolyte membrane based on Nafion and zirconium oxide (ZrO 2) was developed v... more Abstract Polymer electrolyte membrane based on Nafion and zirconium oxide (ZrO 2) was developed via film casting method. The content of ZrO 2 (1.0, 2.0, and 3.0 wt.%) was incorporated with Nafion solution to prepare Nafion-ZrO 2 composite membranes. Recast ...
Eksergi
Alga coklat (Phaeophyta) mengandung senyawa aktif seperti karbohidrat, protein, phenolik, lemak, ... more Alga coklat (Phaeophyta) mengandung senyawa aktif seperti karbohidrat, protein, phenolik, lemak, pigmen, vitamin dan mineral. Kandungan mineral alga coklat sekitar 8-40 % terdiri atas kation Na + , K + , Mg ++ , Fe ++ , Zn ++ , Mn ++ dan logam berat. Bioaktif alga coklat memiliki banyak manfaat, salah satunya adalah Fucoidan sebagai obat kanker. Hambatan pemanfaatan Fucoidan sebagai obat adalah kandungan mineral yang tinggi sehingga mineral tersebut harus dipisahkan. Proses ekstraksi alga coklat menggunakan berbagai metode telah dilakukan dengan tujuan mengisolasi komponen aktif Fucoidan yang bebas dari mineral yang akan menjadi hambatan dalam memanfaatkan komponen aktif. Dalam makalah ini akan diuraikan beberapa metode terbaru ekstraksi bahan aktif alga coklat dan proses pemisahan mineral menggunakan membran Mikro Filtrasi (MF) dan Ultra Filtrasi (UF). Membran MF dan UF dapat memisahkan molekul kecil seperti kation (mineral) dapat lolos melalui membran sehingga makromolekul seperti karbohidrat, lemak, protein, pigmen, phenolic dan vitamin dapat terpisah dari mineral dan diperoleh bahan aktif tanpa adanya mineral. Tujuan dari makalah ini adalah memberikan arah penelitian dalam eksplorasi bahan aktif alga coklat untuk aplikasi farmasi dan kosmetik tanpa efek samping yang disebabkan oleh kandungan logam atau mineral yang tinggi di atas nilai ambang batas di dalam ekstrak alga coklat.
Prosiding Seminar Nasional LPPM, Nov 25, 2021
Covid 19 is a highly contagious respiratory disease caused by the new corona virus. Covid 19 was ... more Covid 19 is a highly contagious respiratory disease caused by the new corona virus. Covid 19 was first discovered in Indonesia in March 2020 and significantly increase. Covid 19 has resulted in restrictions on various social activities, the implementation of the school system and working from home to the closure of tourist attractions and shopping centers, etc. As a result, Indonesia's economy is getting worse. Spraying disinfectants at homes and public facilities is one way to prevent the spread of the corona virus. The purpose of this activity is to provide counseling on how to make disinfectants to break the chain of spread of the corona virus. This activity was carried out in June 2021 which was attended by representatives of several members of the PRTB youth group in Gagaksipat village, Ngemplak, Boyolali. This PKM activity was carried out using several methods, including the lecture method when delivering material about how to make disinfectants, the practical method of making disinfectants and spraying disinfectants into people's homes. This service activity was well received by the participants because after the counseling was carried out, members of the youth group (PRTB) could make disinfectant and apply it for spraying color houses.
Abstrak PRODUKSI BATIK RAMAH LINGKUNGAN DI DUSUN KALIAJIR KIDUL KELURAHAN KALITIRTO,KECAMATAN BER... more Abstrak PRODUKSI BATIK RAMAH LINGKUNGAN DI DUSUN KALIAJIR KIDUL KELURAHAN KALITIRTO,KECAMATAN BERBAH, SLEMAN DAERAH ISTIMEWA YOGYAKARTA Mahreni, Wasir Nuri, Tutik Muji Setyoningrum The natural dye now growing rapidly along with public awareness to induce negative impact of the batic industry. Wealness of batural dye is unstable. Research and development to produce a stable natural dye is still underway. Particullary natural dye to use as a textile and batik dye. Producing batik uses batural dye is more difficult than to produce synthetic dte. So the price is more . expensive. Barrier constranint need to have to find a way out. In this study attempt to use a ne technology that uses technique stamp in order to save time in producing batik The purpos of this study was to produce batik using blue colour of the plant Indigofera tinctoria,the brown colour of the fruit plants Jolawe, brown colour of Mahoni ang green colour of the micture of Indigo and Jo;awe. The result showed that the col...
The eggs produce waste in the form of eggs shell. One alternative to reduce the waste is by proce... more The eggs produce waste in the form of eggs shell. One alternative to reduce the waste is by processin g the egg shell into hydroxy apatite powder. Eggshell is one of the largest sources of calcium carbonate , with 95% of composition. The characteristics of hy droxy apatites that allowed to be used as biomateri als including the mass ratio of Ca:P should have a valu e of 1.67 and have a crystalline structure. In the first step, the eggs shell reacted with hydrochloric acid . Solution formed to the base condition to get the calcium deposits, which then reacted with sodium ph osphate to produce hydroxy apatite deposition. The deposition which formed then dried and heated for f orming the hydroxy apatite crystals. The hydroxy apatite crystals are analyzed by X-Ray Difractometr y (XRD) and Energy Dispersive Spectroscopy X-ray (EDS). From the analysis results, the mass ratio of Ca:P respectively for samples A (0.8 gr CaCO 3 1 mol 20ml HCl and 0.3 mol Na 3PO 4), C (0.8 gr CaCO 3 1 mol 20ml...
Membran komposit telah digunakan dalam proses pemisahan komponen untuk menghasilkan komponen tule... more Membran komposit telah digunakan dalam proses pemisahan komponen untuk menghasilkan komponen tulen dan sebagai elektrolit. Membran nafion sebagai elektrolit dalam sel fuel membrane penukar ion atau Proton Exchange Membrane Fuel Cell (PEMFC) mempunyai kelemahan yaitu konduktiviti Proton dan prestasi selnya akan turun apabila kandungan air di dalam air akan menurun. Bagi mengatasi masalah tersebut, kajian dengan cara menambahkan komponen yang bersifat hidrokofis dan kondukviti tinggi ke dalam kluster polimer nafion telah dilaksanakan. Kajian ini adalah untuk menghasilkan membran nanokomposit campuran nafion-SiO2-PWA menggunakan kaedah sol-gel fasa larutan. Antara parameter yang dikaji adalah suhu penyejatan pelarut, suhu dan waktu penyepuhlindapan dan nisbah TEOS/nafion. Kajian penentuan sifat membran yang dihasilkan adalah morfologi, sifat termal, struktur kimia terbentuk, kandungan kimia, dan kejernihan membran. Prestasi membran komposit sebagai elektrolit dilakukan dengan menggunak...
Penelitian ekstraksi kurkumin dari kunyit dengan pelarut etanol telah dilakukan dalam kolom yang ... more Penelitian ekstraksi kurkumin dari kunyit dengan pelarut etanol telah dilakukan dalam kolom yang diisi dengan kunyit sebagai unggun tetap dan pelarut mengalir secara kontinyu dari atas kolom. Kurkumin yang terekstrak dari kunyit dianalisa setiap waktu tertentu dengan mengukur indek biasnya dengan menggunakan alat Refraktometer. Pengamatan dihentikan setelah konsentrasi kurkumin di dalam pelarut tetap. Penelitianini dilakukan untuk menentukan model perpindahan massa padat-cair dengan mengamati variable kecepatan aliran pelarut, diameter kolom, dan tinggi unggun. Model matematis disusun berdasarkan neraca massa kurkumin yang bergerak dari dalam padatan ke permukaan kemudian mendifusi ke dalam aliran pelarut yang bergerak dari atas ke bawah kolom dapat dinyatakan dengan persamaan sebagai berikut :D_AB (d^2 CA)/(dZ^2 )+V (dCA)/dZ+KCA (HXA-CA)=∈(dCA)/dt; (dXA)/dt=-KCA/ρB (CA*-CA).Penyelesaian persamaan diatas dengan cara eksplisit dan optimasi didapatkan harga KCA yang diperoleh antara 0...
Nafion-Silica oxide (SiO2)-Phosphotungstic acid (PWA) composite membrane have been synthesized us... more Nafion-Silica oxide (SiO2)-Phosphotungstic acid (PWA) composite membrane have been synthesized using solution phase sol-gel method. The effect of the weight ratio of Nafion:SiO2:PWA to the electrochemical properties of composite membrane when applies as electrolyte in the PEMFC was investigated using Fuel Cell Test System (FCTS) at temperature of range of 80 – 90 oC and 40% relative humidity (RH). The weight ratio of the composite membrane samples varied in the range of 100:2.88:1.15, 100:4.33:1.73 and 100:5.76:2.30 and designated as NS10W, NS15W and NS20W, respectively. The aim of the experiment was to insert the inorganic hygroscopic and high conductivity filler like PWA and SiO2 in the Nafion matrix to order to improve the water retention, proton conductivity (σ), hydrogen crossover (β), and thermal stability in addition to increase PEMFC performance at elevated temperature and low RH condition. The result showed when appropriately embeded in the Nafion cluster, the hydrated PWA ...
NANOCOMPOSITE ELECTROLYTE MEMBRANE FOR MODERATE TEMPERATURE AND LOW RELATIVE HUMIDITY HYDROGEN PR... more NANOCOMPOSITE ELECTROLYTE MEMBRANE FOR MODERATE TEMPERATURE AND LOW RELATIVE HUMIDITY HYDROGEN PROTON EXCHANGE MEMBRANE FUEL CELL (HPEMFC) APPLICATlON Mahreni, A.B. Mohamad, A.A.H. Kadhum, W.R.W. Daud Department of Chemical Engineering -Faculty of Technology Industry- University Pembangunan Nasional Yogyakarta-Indonesia Institute of Fuel Cell- Universiti Kebangsaan Bangi - Malaysia 43600 Nowadays PEMFC with hydrogen fuel has developed to commercialize to replace the conventional machine. Several limitations in PEMFC commercialization are its low efficiency, viability of hydrogen fuel supply and problem of controlling fuel and water as reaction products. Effective effort to increase efficiency and water management include elevating temperature of PEMFC operation near water boiling point to increase energy produced, prevent water flooding, enhanced cooling efficiency and also the possibility to use hydrogen and air under lower humidity in order to make simples PEMFC design. But at ele...
Waste of chemical laboratory without dilution was analyzed and it was found that pH = 5.5 while (... more Waste of chemical laboratory without dilution was analyzed and it was found that pH = 5.5 while (COD=171 717 mg/L) and BOD = 10500.1 mg/L) . This research carried out to reduce COD and BOD using flocculation and coagulation processes. Research has been done by mixing the waste with Alum in a flask equipped with a stirrer. Waste is stirred for 15 minutes at a constant speed of 150 rpm. After that the pH of the waste is increased by adding Calcium hydroxide Ca(OH)2 so as to achieve a certain pH. The addition of alum and Ca(OH)2 caused the formation of flock. The flock formed more and more, and left without stirring for 24 hours for maximum flock formation. Further separation of flock using a filter. The COD-BOD of the supernatant is analized. The purpose of the study to determine the pH and the ratio of alum:waste to the reduction of are greatly affect the reduction of COD/BOD. Reduction of COD/BOD highest achieved at pH 12.2 and the ratio of alum/waste is 1/0 (ml/ml) ( COD reduction ...