Judul: Pemanfaatan Pod Kakao untuk Produksi Etanol melalui Hidrolisis Menggunakan Kapang Aspergillus niger dan Trichoderma viride
Abstrak: Indonesia is one of the largest cocoa producing country in the world, and according to harvest data from 2005, Indonesia produces 13% cocoa from the total world cocoa demand. Fresh cocoa fruit consists of 75.50% of the fruit shells, 21.18% of seeds and 2.60% of placenta. Cocoa pod is one of lignoselulosic waste containing of 31.25% cellulose. The cellulose composition large enough to make cocoa pod potential to be processed into ethanol. So far, ethanol production is more focused on raw materials such as cassava, sweet potatoes, sugar cane, sago, and several types of starch which is less effective because these materials compete with food. This research aimed to find out the effects of substrate’s type of cocoa pod, the type of mold, and time of hydrolysis optimized to produce high levels of reducing sugar and producing ethanol from the best hydrolisate. This research were performed into three stages. The first stage was the preliminary stage that includes the characterization of cocoa pods and pretreatment on cocoa pod including reduction in size, degumming, and delignification. The second stage was the hydrolysis of cocoa pod using two types of fungus (Aspergillus niger and Trichoderma viride), two types of substrates (non-delignified and delignified cocoa pods), hydrolysis time (11 days), sampling on days 1, 3, 5, 7, 9, and 11. Last stage was the fermentation using the best hydrolisate, using Saccharomyces cerevisiae culture. This research utilized completely randomized factorial design with three factors and two replications. The first factor was the type of fungus, which consists of two levels of Aspergillus niger and Trichoderma viride. The second factor was the hydrolysis time with 6 degree of day (1, 3, 5, 7, 9, and 11). The third factor was the type of substrate with two levels of the substrate non-delignified and delignified cocoa pods. Material characterization results obtained the cellulose content of cocoa pods is 28.78% (wb), Hemicellulose 8.70% (wb) and 42.90% lignin (wb). After delignification the results obtained cellulose content is 32.23% (wb) and 31.00% lignin (wb). The delignification efficiency was 27,74%. Based on the results of range analysis with α <0.05 at the hydrolysis stage substrate types affected significantly on reducing sugar concentration, whereas the type of fungus and hydrolysis time does not affect real.
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Judul: Hidrolisis Enzimatis Pod Kakao (Theobroma cacao) Untuk Produksi Etanol
Abstrak: Cacao beans as crops that have been used widely in the food industry as well. Cacao production in Indonesia in 2007 reached 532,000 tons. That amount continues to be increased because the government has projected cacao production in 2013 reached 1 million tons (Anonymous, 2009). This increase also resulted in increased waste produced by the cacao pod, so the cacao pod has a great potential to be developed into products that have added value. In addition to substitute ethanol consumption projection 5% premium (E5) in Indonesia from 2007-2010 on target about 5% and year 2011 to 2015 targeted approximately 10% (Dept. of Energy and Mineral Resources, 2007). The purpose of this research is to obtain the best concentration and duration of hydrolysis using cellulase enzymes to produce sugars from cacao pod to manufacture bioethanol and measuring the percent conversion and the yield produced from the fermentation process using sugar as enzyme hydrolysis of cacao pod. This research was conducted in four stages, namely the first phase of the characterization of raw materials. The second stage of degumming and delignification. The third phase of the fourth stage of hydrolysis and fermentation. Degumming done to eliminate pectin on cacao pod using Ca(OH)2. Delignification carried out to reduce lignin content and degree of crystallinity. Delignification of chemical compounds made with NaOH 0.68% and 30% H2O2. Hydrolysis of cacao pod using enzymatically treated with cellulase enzyme concentrations 10, 20, 30 and 40 IU/g substrate and the hydrolysis time of 4, 8, 12, 24, 36, 48 and 60 hours. Analysis carried out include: reducing sugar content, total sugar content and dekstros equivalent. From the results of proximate analysis of materials used has a crude fiber content of 50.41%. Crude fiber fraction contained 28.78% cellulose, hemicellulose and lignin 8.70%, 42.90%. Before delignification lignin content of 42.90% and amounted to 31.00% after a delignification. On the use of 40 IU/g substrate during 48 hours of total sugar conversion result obtained the highest towards the raw materials used amounted to 3.2% (w/w) but the highest reducing sugar conversion is obtained for materials obtained after 60 hours of the registration 2.24% (w/w). Concentration of ethanol produced in fermentation processes for 0.16% (w/v) ethanol yield value of the cacao pod of 3.16% and the efficiency of substrate 62.5% (w/v).
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Judul: Teknik penentuan posisi bintang berdasarkan pelat foto overlapping
Abstrak: Bintang adalah salah satu objek langit yang menarik untuk diamati. Untuk itu, pengetahuan tentang posisi bintang sangat diperlukan. Posisi bintang di langit dapat dihitung melalui foto bintang. Fotografi astronomi atau astrometri merupakan ilmu yang mempelajari metode untuk menentukan posisi bendabenda langit seperti bintang berdasarkan pelat foto (Kamp, 1967). Sebuah pelat foto berisi citra bintang-bintang yang sudah diketahui posisinya berdasarkan katalog dan citra bintang-bintang yang belum diketahui posisinya. Posisi bintang yang ada di katalog dinyatakan dengan (a,3). Bintang yang belum diketahui posisinya lebih banyak jumlahnya daripada bintang yang sudah diketahui posisinya. Citra bintang pada pelat foto berupa sebuah titik dalam bentuk tetap. Posisinya pada pelat merupakan hasil pengukuran pada bidang kartesius dan dinyatakan dengan (1;,fl). Hasil pengukuran tersebut kemudian direduksi menjadi koordinat terukur (x,y). Hubungan antara (a,3) dan (x,y) didekati dengan sebuah deret dengan konstanta-konsranta deret merupakan konstanta pelat. Nilai konstanta pelat diperoleh dengan menggabungkan hasil pengukuran posisi bintang pada masing-masing pelat menjadi sebuah persamaan normal (Jefferys, 1963). Hasil akhir dari gugus persamaan normal tersebut dijabarkan dalam bentuk nOlasi matriks partisi dan berupa sebuah sistem persamaan linier Ax = b di mana A adalah matriks jarang, dan x merupakan konstanta pelar yang akan dicari nilainya. Untuk menyelesaikan sistem persamaan linier terse but digunakan metode transformasi given. Konstanta pelat yang sudah diperoleh dengan menyelesaikan sistem persamaan linier di atas, kemudian disubtitusi ke sebuah persamaan untuk memperoleh posisi bintang yang tidak tercantum dalam katalog. .
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