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"Palm Oil Mill Effluent (POME) is an agro-industrial waste product with high availability and which contains high quantities of organic compounds that are necessary for microbial growth. Cultures of Pseudomonas aeruginosa were grown in POME to produce lipase using the submerged fermentation method. The objective of this study is to obtain the optimum value of lipase activity produced by the cultures of Pseudomonas aeruginosa using POME as the substrate through the submerged fermentation method and to obtain the dry extract of lipase. In the study, the one factor at a time (OFAT) method was applied, which allowed observation of the effect of inoculum and additional nutrient concentrations, such as Ca2+ ion, olive oil, peptone and Tween 80, on the activity of lipase. These factors were investigated in shake flask fermentation at 30°C over 96 hours. The activity unit of lipase was determined by the titrimetric reaction of olive oil hydrolysis using crude lipase. The optimum value of the lipase activity unit (1.327 U/mL) was gained when 3% (v/v) of inoculum, 4 mM of Ca2+ ion, 0.4% (v/v) of olive oil, 0.9% (m/v) of peptone, and 0.9% of Tween 80 were added into the medium. Crude lipase was then dried using a spray dryer. Subsequently, 15.643 g of dry extract lipase was obtained from 500 mL of cell free supernatant. In further research, the lipase activity assay would be better achieved using the p-nitrophenyl palmitate hydrolysis method and examined by a spectrophotometer."

"Penelitian ini bertujuan untuk mengetahui pengaruh perlakuan panas pasca las terhadap sifat mekanis sambungan las tabung LPG 3 kg. Pengelasan dilakukan pada baja karbon rendah JIS SG 295 yaitu material yang banyak digunakan untuk fabrikasi tabung LPG 3 kg.Teknik pengelasan yang digunakan adalah Submerged Arc Welding (SAW) selanjutnya dilakukan proses perlakuan panas pasca las. Penelitian dilakukan dengan melakukan variasi perlakuan panas pasca las terhadap sambungan las tabung LPG 3 kg meliputi : tanpa perlakuan panas, dengan perlakuan panas temperatur 6000C dan 6500C, masing masing dengan waktu 10, 30, 45 dan 60 menit. Untuk mengetahui pengaruh perlakuan panas pasca las terhadap sifat mekanisnya, dilakukan beberapa pengujian yang meliputi uji tarik, uji kekerasan serta foto struktur makro dan mikronya.Dari penelitian ini diperoleh kesimpulan bahwa waktu dan temperatur perlakuan panas pasca las tidak memberikan pengaruh yang signifikan terhadap kekuatan mekanis sambungan las tabung LPG 3 Kg. Namun demikian ditemukan ketidaksesuaian bentuk sambungan joggle offset terhadap ketentuan SNI 1452-2007.

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This study aims to determine the effect of post weld heat treatment on mechanical properties of weld joint of 3 kg LPG bottle. Welding is performed on low carbon steel JIS SG 295 as a widely used material for the manufacture of 3-kg LPG bottle.

Welding technique used is Submerged Arc Welding (SAW) and continued with the process of post weld heat treatment. Research was carried out by doing a variation of post weld heat treatment for 3 kg LPG bottle including : no heat treatment, heat treatment with temperature of 6000C and 6500C, with a holding time of 10, 30, 45 and 60 minutes respectively. To study the effect of post-weld heat treatment on the mechanical propertiy ? structure relationship, a number of examination was performed, including : tensile test, hardness test, macrostructure and microstructure examination.

The results obtained concluded that the time and temperature post-weld heat treatment does not have a significant effect on mechanical properties of weld joint of 3 Kg LPG bottle. However, we found that the join design (joggle offset) not comply with SNI 1452-2007."

"Cadangan bijih mangan kadar rendah di Indonesia cukup besar, namun cadangan bijih mangan tersebut tidak dapat dimanfaatkan secara optimal karena rendahnya rasio Mn/Fe.Sehingga diperlukan penelitian untuk mempelajari metode benefiasi guna meningkatkan rasio Mn/Fe, menggunakan bijih mangan kadar rendah dari Kabupaten Tanggamus (MnO=15.30%, rasio=0.91) dan kabupaten Jember (MnO=28.66%, rasio=1.39) supaya bisa dijadikan bahan baku dalam pembuatan FeMn menggunakan SAF.Penelitian benefisiasi bijih mangan kadar rendah dimulai dengan melakukan fraksinasi untuk mendapatkan ukuran butir 841-420 μm, 420-250 μm dan 250-177 μm kemudian dilakukan proses pemisahan gravitasi untuk menghasilkan concentrate dan tailing yang akan digunakan sebagai bahan baku untuk reduction reduction roasting. Proses reduction roasting dilakukan dengan variasti suhu 500°C, 700°C dan 900°C serta variasi waktu reduction roasting 30, 60, 90 dan 120 menit dan kemudian dilakukan proses pemisahan secara magnetic. Material non magnetik yang menghasilkan peningkatan rasio Mn/Fe paling optimum akan dilakukan proses briketisasi untuk digunakan sebagai bahan baku pembuatan FeMn menggunakan SAF.Pengaruh variasi temperatur dan waktu reduction roasting memberikan hasil rasio Mn/Fe optimum 6.11, pada partikel non magnetik ukuran 841-420 μm dengan suhu reduction roasting 700°C selama 60 menit. Proses reduction roasting juga menyebabkan munculnya fase baru seperti Hausmanite (Mn3O4), Manganosite (MnO), Fayalite (Fe2SiO4) dan Phlogopite (KMg3(AlSi3O10(OH)2), akibat proses perubahan fase pada bijih mangan. Fase mineral tersebut muncul pada reduction roasting variasi waktu 60 menit, 90 menit dan 120 menit, serta muncul pada variasi suhu 500°C, 700°C dan 900°C.Pada pengujian dalam SAF digunakan basisitas berdasarkan stoichiometri dengan nilai 1.17, 1.32, 1.15 dan basisitas referensi hasil penelitian Bobby et al, 2015, dengan nilai 0.7. Penggunaan basisitas 0.7 menghasilkan kenaikan berat metal dan menurunkan berat terak pada saat diproses dalam SAF. Selain itu basisitas stoichiometry hanya menghasilkan ferromangan dengan Mn=35.47% dan basisitas referensi 0.7 menghasilkan Ferromangan dengan Mn=60%.Hasil penelitian ini menunjukkan bahwa peningkatan rasio menggunakan benefisiasi bisa mencapai rasio 6.11. Sedangkan proses pembuatan FeMn dengan menggunakan bijih mangan kadar rendah pada submerged arc furnace bisa menghasilkan kadar Mn 60% dengan kontrol pada basisitas untuk mengurangi volume terak, meningkatkan berat logam dan menaikkan kadar Mn.

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Low grade manganese ore reserves in Indonesia is quite large, but manganese ore reserves can not be used optimally because of the low ratio of Mn / Fe.In that case, research is needed to study the methods of benefiasiation to increase the ratio of Mn / Fe, using low grade manganese ore from Tanggamus ( MnO = 15.30% ratio = 0.91) and Jember (MnO = 28.66%, ratio = 1.39) that can be used as raw material in the manufacture of FeMn using SAF.

Research for beneficiation of low grade manganese ore started by fractionation to obtain the grain size of 841-420 μm, 420-250 μm dan 250-177 μm then performed meja getar process to produce the concentrate and tailings to be used as ingredients raw for reduction roasting. Reduction roasting variety process carried out with a temperatur of 500 °C, 700 °C and 900 °C and roasting time variation of 30, 60, 90 and 120 minutes and then a magnetic separation process. Non-magnetic material that produces an increase in the most optimum ratio of Mn/Fe will be used into bricketing process as raw material for FeMn using SAF.

The effect of variation of temperatur and roasting time results ratio of Mn/Fe optimum 6.11, on a non-magnetic particle size of 841-420 μm with a roasting temperature of 700 °C for 60 minutes. Roasting also cause new phase occurensces such as Hausmanite (Mn3O4), Manganosite (MnO), Fayalite (Fe2SiO4) and Phlogopite (KMg3(AlSi3O10(OH)2), due to the process of phase changes in manganese ore. Mineral mineral appeared on roasting with time variations 60 minutes, 90 minutes and 120 minutes, as well as appearing on the variation in temperatur of 500 °C, 700 °C and 900 °C.

On testing in the SAF used basicity based stoichiometri with a value of 1.17, 1.32, 1.15 and reference basicity 0.7 based on the Bobby et al, 2015 reserach. Influence of basicity resulted in an increase of weight of metal and decrease the weight of slag during processing in the SAF. In addition basicity stoichiometry produces only ferromangan with Mn = 35.47% and reference basicity 0.7 generate Ferromangan with Mn = 60%.

The results of this study showed that increasing the ratio of Mn/Fe using beneficiation could reach a ratio 6.11. While the process of making FeMn using low grade manganese ore at Submerged arc furnace can produce 60% Mn grade with controls on basicity to reduce the volume of slag, improve and raise the level of heavy metals Mn."

"Pengolahan air limbah domestik PT GS Battery dengan Bio Kleen Sewage System masih menghasilkan konsentrasi amonia effluen yang melebihi baku mutu. Aerated Submerged Fixed Film Reactor yang diketahui mampu mengolah beban amonia tinggi, diterapkan untuk mengolah air limbah tersebut dan dievaluasi selama 45 hari. Penelitian skala laboratorium dilakukan menggunakan bioreaktor dengan kapasitas 5.6 L yang dioperasikan pada waktu detensi yang berbeda, yaitu 6, 8, dan 10 jam. Lumpur aktif resirkulasi dari instalasi pengoalahan air limbah Jababeka digunakan sebagai lumpur pembibitan. Kualitas influen penelitian memiliki laju beban Chemical Oxygen demand COD dari 1181 sampai 1987 g COD m-3 hari-1 dan laju beban analisis dari 134 sampai 223 g NH3-N m-3 hari-1. Hasil penelitian menunjukkan performa yang lebih baik pada HRT 10 jam, dimana sistem mencapai 90 ndash; 93 dan 94 ndash; 99 pada efisiensi penyisihan COD dan analisis. Data yang diperoleh menunjukkan nilai R-kuadrat 0.87 dan 0.85. Konsentrasi effluen COD dan amonia memiliki rentang 36 ndash; 60 mg/L dan 0.4 ndash; 5 mg/L dimana keduanya telah memenuhi standar baku mutu di Indonesia. Penelitian ini juga menunjukkan dua kondisi aerobik dan anaerobik dapat bekerja dalam satu bioreaktor.

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Domestic wastewater treatment in PT GS Battery using Bio Kleen Sewage System still produced ammonia concentration above effluent discharge standard. Aerated Submerged Fixed Film Reactor which known for its ability to treat high ammonia loading, was used and evaluated during 45 days. Laboratory experiment were conducted using a bioreactor with 5.6 L capacity operated at different hydraulic retention times, which were 6, 8, and 10 hours. Return activated sludge from wastewater treatment plant of Jababeka was taken as seed sludge. The influent of the experiment has Chemical Oxygen Demand COD loading rate from 1181 to 1987 g COD m 3 day 1 and ammonia loading from 134 to 223 g NH3 m 3 day 1. Results indicated better performance at 10 hours rsquo retention time that the system was able to achieve 90 ndash 93 and 94 ndash 99 removal efficiencies of COD and ammonia. Data gained exhibited the R squared value were 0.87 and 0.85. The effluent COD and ammonia concentration ranged between 36 ndash 60 mg L and 0.4 ndash 5 mg L which lower than the Indonesian national discharge standards for both parameters. The present study showed also two conditions of aerobic and anaerobic could be worked in a single bioreactor."

"Indonesia memiliki potensi yang besar dalam memproduksi enzim untuk industri bioteknologi. Sayangnya, dengan sumber daya alam yang melimpah, enzim untuk industri bioteknologi masih diimpor. Perkembangan produksi enzim di Indonesia harus didukung untuk menurunkan tingkat impor enzim. Industri biodiesel merupakan salah satu industri bioteknologi yang memanfaatkan enzim untuk produknya. Lipase adalah enzim utama dan berperan sebagai biokatalis untuk produksi biodiesel. Produksi enzim lipase dari Rhizopus oryzae dikembangkan dengan menggunakan metode fermentasi solid state dan submerged untuk menghasilkan enzim lipase dalam jumlah tinggi dengan limbah pertanian yang dimanfaatkan sebagai substrat untuk produksi lipase. Kondisi optimum untuk produksi lipase ditemukan dengan berbagai waktu, konsentrasi substrat dan konsentrasi induser dari fermentasi. Waktu fermentasi divariasikan menjadi 1, 3, 5, dan 7 hari dengan variasi konsentrasi substrat 0.5, 1, 1.5, 2, and 2.5, substrat yang digunakan adalah dedak gandum. Dan variasi induser adalah 2, 4, 6, dan 8. Ekstraksi akan dilakukan melalui kain muslin, sentrifugasi dan disaring dengan kertas saring. Lipase yang dihasilkan adalah enzim lipase basah dan kering. Titrasi digunakan sebagai uji enzimatik untuk aktivitas lipase. Dengan kondisi optimum dari konsentrasi inducer 6,9, konsentrasi substrat 1,9 dan 3,5 hari periode fermentasi. Aktivitas unit yang dihasilkan dari lipase 62,67 U/ml dan 50 U/ml untuk Submerged Fermentasi dan Solid-State Fermentation masing-masing. Dengan hasil sintesis biodiesel sebesar 38,11 melalui rute non-alkohol.

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Indonesia has huge potentials on producing enzymes for biotechnology industries. Unfortunately, with abundant natural resources, the enzymes for biotechnology industries were still imported. The development of enzyme production in Indonesia should be supported in order to reduce the import level of enzymes. Biodiesel industry is one of the biotechnology industries that utilizes enzyme for their product. Lipase is the main enzyme and act as the biocatalyst for the production of biodiesel. The production of lipase enzyme from Rhizopus oryzae are developed using the Solid State fermentation and Submerged fermentation method in order to yield high amount of lipase enzyme with the agricultural waste is utilize as the substrate for the lipase production.

The optimum condition for the production of lipase is discovered by varying time, substrate concentration and inducer concentration of the fermentation. The time of fermentation is 1, 3, 5, and 7 days with substrate concentration variation of 0.5, 1, 1.5, 2, and 2.5, the substrate used is Wheat Bran. And the variation of the inducer is 2, 4, 6, and 8. The extraction will be done by squeezing the suspension through muslin cloth, centrifugation and filtered by filter paper. Titration is used as the enzymatic assay for the lipase activity. Under optimum condition of 6.9 inducer concentration, 1.9 substrate concentration and 3.5 day of fermentation period. Resulting unit activity of lipase of 62.67 U ml and 50 U ml for Submerged Fermentation and Solid State Fermentation respectively. With biodiesel synthesis yield of 38.11 through non alcohol route. "