Judul: Study of carbon to nitrogen ratio (c/n) in the process composting with aeration treatment using of boiler ash and sludge in sugarcane industry
Abstrak: Boiler ash and sludge wastes in the sugarcane industry has not been used optimally. Therefore, it is necessary to studies use of composting. The purpose of study to determine influence of aeration on composting treatment to the value of C/%. The research method using complete randomized design with two treatments, namely active aeration treatment with air drainage and passive aeration (without air drainage). The aeration active composting in the first week, then in the second week until the end of composting by air supply naturally. Composting consists of three composition, that is a mixture of sludge without boiler ash, boiler ash with a mixture of 20% sludge and boiler ash with a mixture of 40% sludge. The research was carried out two stages, that is preliminary research to determine composition of raw materials mixture, and primary research to determine C/% value during composting. Parameters monitored during composting such as, temperature is done every day, pH and C/% is a every week. The composting with aeration treatment of active and passive aeration does not significantly affect the value of C/%, but the addition of sludge composition significantly affect the value of C/% by anova statistic. More sludge is added to produce the value of C/% is lower. The results of the compost, physically, the value of C/%, pH value does not meet the requirements of the compost, but the contents of potassium and phosphorus in accordance with the requirements of the compost to S%I 19-7030-2004.
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Judul: Co-composting bagasse with sludge sugar industry waste using aeration techniques and its effect in value of c/n
Abstrak: Bagasse is the solid waste sugar industry and relatively abundant (30-40%). Sugarcane planted area in Indonesia reaches 395,399.44 hectare and potentially to achieve national bagasse 39,539,944 tons per year. As well as produced sludge each day around 10-50 %. Sludge has quite high carbon content and nitrogen, thus potentially to be composting. Co-composting is one of the alternative solutions in the utilization of industrial solid waste of sugar. One of them is the bagasse and sludge with complementary characteristics, thus simplifying the process of composting. Composting methods and that techniques applied are aerated static pile system and using two factorial of aeration and formulation. Aeration factor conducted by active and passive aeration, while the formulation conducted by a factor of 0%, 25%, and 50% sludge. Composting process carried out during the sixty days with active aeration at first week. Analysis results showed that aeration technique proved didn’t have significant effect in changing C/N value. After analysis of variance and advanced test showed that the formulation of three different stages proved significantly different of C/N and significant at 50% sludge. Generally, aeration factor and formulation are not related yet and do not have any significant interaction to co-composting C/N value. There is need for advanced research until the value of C/N can achieve the appropriate standard of quality compost.
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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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