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"Pengembangan energi terbarukan merupakan salah satu tantangan yang harus dihadapi. Lumpur tinja menjadi salah satu alternatif pilihan dalam pengembangan energi tebarukan karena memiliki nilai kalor hingga 19,1 MJ/kg TS. Sehingga, berpotensi diubah menjadi Refused Derived Fuels (RDF). Akan tetapi, lumpur tinja masih memiliki nilai kadar air yang tinggi sehingga perlu proses pengeringan terlebih dahulu dengan menggunakan metode biodrying. Penelitian ini bertujuan untuk mengetahui karakteristik pertumbuhan mikroorganisme ketika terjadi variasi fraksi organik terhadap pengeringan lumpur tinja dengan metode biodrying. Berdasarkan pengujian tersebut diperoleh fakta bahwa bakteri mesofilik cenderung meningkat pada dua minggu pertama sedangkan bakteri termofilik meningkat pada satu minggu pertama dan ditemukan kolerasi yang lemah antara pertumbuhan mikroorganisme terhadap perubahan variabel volatile solids. Sementara itu, reaktor dengan penambahan fraksi organik terbesar menghasilkan nilai kalor paling baik, yaitu sebesar 14.66 MJ/Kg, kadar air paling rendah, sebesar 37.15%, dan volatile solids paling besar, 30.93%.

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Developing a renewable energy is one challenge that we have to face in the future. Faecal sludge could be an alternative solution in developing renewable energy sources since it has heating value up to 19.1 MJ/Kg TS. Hence, faecal sludge could be processed to Refused Derived Fuel. In the other side, faecal sludge has a high moisture content and should be dried before. This study tried to analyze the characteristics of faecal sludge biodrying and see the microbes activity behind the drying process with different organic fraction mixing. To answer the objectives, this experiment using several key parameters suh as temperature, moisture content, volatile solids, and the amount of mesophilic and thermophilic bacteria. The result of this study shows that mesophilic bacteria increased in the first two weeks while thermophilic bacteria increased in the first week and found a low correlation between the growth of microorganisms to changes in volatile solids. Meanwhile, the reactor that with the highest organic fraction shows the best result with calorific value up to 14.66 MJ/Kg, lowest moisture content, 37.15%, and has the highest volatile solids, which is 30.93%."

"Lumpur tinja berpotensi untuk dimanfaatkan sebagai bahan energi terbarukan, akan tetapi karena karakteristiknya yang memiliki kadar air relatif tinggi diperlukan proses pengeringan terlebih dahulu dengan menggunakan metode biodrying dan hasilnya dapat digunakan sebagai bahan baku refused derived fuel (RDF). Penelitian ini menggunakan 3 desain reaktor dengan rasio pencampuran fraksi organik yang berbeda-beda, yaitu sebesar 31 persen, 40 persen, dan 47 persen. Kemudian dilakukan pengujian parameter kunci dari biodrying, antara lain suhu, kadar air, volatile solid, dan nilai kalor, serta dilakukan juga pengujian tingkat biostabilitas dari feedstock. Berdasarkan hasil yang diperoleh, biodrying menggunakan lumpur tinja dan campuran material organik mampu meningkatkan suhu feedstock hingga rentang 48-52 derajat C, dengan suhu tertinggi terjadi pada Reaktor 2, menurunkan kadar air hingga 5-12 persen, dan kadar volatile solid terendah dicapai Reaktor 3, sebesar 36.57 persen. Pada durasi biodrying hari ke-15, nilai kalor tertinggi terjadi pada Reaktor 3, yaitu sebesar 14.66 MJ/kg, serta tingkat stabilitas tertinggi terjadi pada Reaktor 2 sebesar 0.3 O2.g TS-1.jam-1.

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Faecal sludge has a potential to be used as renewable energy materials, however, since its characteristics which have high moisture content, a drying process is needed using biodrying method that produce raw materials for refused derived fuel (RDF). This study investigated the biodrying performance of three reactor designs using different organic mixing fractions: 31% (Reactor 1), 40 persen (Reactor 2), and 47 persen (Reactor 3) on key parameters, such as temperature, moisture content, volatile solid, and calorific value. In addition, biostability of the feedstock biodrying will also be investigated.

Based on the results obtained, the performance of biodrying using faecal sludge and organic fractions increase the temperature to a range of 48-52 derajat C, with the highest temperature occurring in Reactor 2, which is 51.4 derajat C, and decrease moisture content to 5-12 persen, with the lowest volatile solid content reached 36.57 persen in Reactor 3. At the 15th day biodrying process, the highest calorific value of mixing fraction reached 14.66 MJ / kg occurred in the Reactor 3. Besides, the highest level of biostability is equal to 0.3 O2.g TS-1.hour-1 which occurs in Reactor 2."

"This book introduces the numerical technique of polynomial continuation, which is used to compute solutions to systems of polynomial equations. Originally published in 1987, it remains a useful starting point for the reader interested in learning how to solve practical problems without advanced mathematics. Solving Polynomial Systems Using Continuation for Engineering and Scientific Problems is easy to understand, requiring only a knowledge of undergraduate-level calculus and simple computer programming. The book is also practical; it includes descriptions of various industrial-strength engineering applications and offers Fortran code for polynomial solvers on an associated Web page. It provides a resource for high-school and undergraduate mathematics projects."

"Karies merupakan suatu kerusakan progresif dari enamel, dentin dan sementum, yang disebabkan oleh adanya aktivitas mikroba pada permukaan gigi yang rentan. Bakteri utama yang dikenal sebagai penyebab karies gigi adalah Streptococcus mutans. Saat ini, penggunaan bahan alami sebagai obat alternatif yang baik untuk pengobatan karies gigi mulai dikembangkan. Penelitian ini bertujuan untuk mengisolasi bromelain dari bonggol nanas Ananas comosus L. Merr. dan dilakukan tahap pemurnian dengan fraksinasi bertingkat menggunakan aseton dan amonium sulfat. Fraksi bromelain yang diperoleh pada setiap tahap pemurnian dengan nilai aktivitas spesifik tertinggi diuji aktivitas antibakterinya dengan menggunakan metode difusi cakram. Enzim kasar yang diperoleh sebelum difraksinasi menunjukkan adanya aktivitas proteolitik dan memiliki nilai aktivitas spesifik sebesar 52,318 Unit/mg. Hasil fraksinasi larutan enzim kasar dengan aseton menghasilkan fraksi 3 dengan kejenuhan 50-80 yang memiliki aktivitas spesifik tertinggi sebesar 87,778 Unit/mg dengan tingkat kemurnian 2 kali dibandingkan larutan enzim kasar. Fraksinasi lebih lanjut menggunakan amonium sulfat menghasilkan fraksi 3 dengan kejenuhan 50-80 yang memiliki nilai aktivitas spesifik meningkat menjadi 260 Unit/mg dengan tingkat kemurnian 5 kali dibandingkan larutan enzim kasar. Proses dialisis dilakukan pada fraksi 3 amonium sulfat dapat menaikkan nilai aktivitas spesifik menjadi 340,926 Unit/mg dengan tingkat kemurnian menjadi 6 kali. Pengujian aktivitas antibakteri dilakukan terhadap enzim kasar, fraksi 3 aseton, dan fraksi 3 amonium sulfat. Sebagai kontrol negatif digunakan larutan buffer fosfat 0,2 M pH 7,0. Sebagai kontrol positif digunakan klindamisin untuk bakteri uji Streptococcus mutan dan metronidazol untuk bakteri uji Porphyromonas gingivalis. Uji antibakteri dari enzim kasar terhadap kedua bakteri uji menghasilkan zona bening dengan kategori daya hambat lemah yaitu sebesar 12 mm. Pengukuran zona bening yang diperoleh pada fraksi 3 amonium sulfat terhadap bakteri uji Porphyromonas gingivalis menunjukkan nilai yang sama dengan kontrol positifnya yaitu sebesar 21 mm, sedangkan pada fraksi 3 aseton tidak menunjukkan adanya zona bening untuk bakteri uji tersebut.Untuk bakteri uji Streptococcus mutan, klindamisin menghasilkan zona bening sebesar 38 mm.

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Caries is a progressive deterioration of enamel, dentine, and cementum, initiated by microbial activity on the vulnerable tooth surface. The main bacteria that cause dental caries is Streptococcus mutan. The use of such natural material as alternative medicine to cure caries began to be developed. The objective of this study was to isolated bromelain from pineapple core Ananas comosus L. Merr. and purification by multilevel fractionation using acetone and ammonium sulphate. The fraction of bromelain in each purification step with the highest specific activity value was tested for its antibacterial activity by method of paper disc diffusion. Crude enzyme solution before fractionation showed proteolitic activity and has specific activity value equal to 52,318 Unit mg. Result of fractionation of crude enzyme solution using acetone produce third fraction with level of saturation is 50 80 that has highest specific activity equal to 87,778 Unit mg with level of purity equal to 2 times compared to crude enzyme solution. Further purification by fractionation using ammonium sulfate produces third fraction with level of saturation is 50 80 which has a specific activity value increased to 260 Unit mg with level of purity 5 times compared to crude enzyme solution. Process of dialysis was carried out in the third fraction that was result of fractionation using ammonium sulphate was increased specific activity value to 340,926 Unit mg with level of purity is 6 times. Fraction of enzymes which used to tested for antibacterial activity are crude enzyme, the third fraction of acetone fractionation and the third fraction of ammonium sulphate fractionation. Negatife control was used 0,2 M phosphate buffer solution pH 7,0 and positive control was used clindamycin for Streptococcus mutan bacteria and metronidazole for Porphyromonas gingivalis bacteria. Test of antibacteria from crude enzyme for both of bacteria showed clear zone with weak inhibitory category equal to 12 mm. The largest clear zone measurements were obtained at the third fraction of ammonium sulphate fractionation in Porphyromonas gingivalis bacteria that has same value with metronidazole as its positive control equal to 21 mm. Beside that, third fraction of acetone fractionation did not produce clear zone in both bacteria. Clindamysin in Streptococcus mutan bacteria produce clear zone equal to 38 mm. "