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: Pengomposan Blotong, Bagas dan Abu Ketel dari Industri Gula dengan Perlakuan Aerasi Aktif dan Perbedaan Nilai C/N Awal
Abstrak: Filter Cake, Bagasse and Boiler wastes in the sugarcane industry has not been used optimally. Therefore, it is necessary to studies use of composting. The purposes of study are to optimize the wastes utilization with composting and to know the influence of different active aerationrate and different initial C/N value on composting process and product. 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 based on initial C/N value, they are 30, 40 and 50. In term of active aeration rate, composting consists of two aeration rate, they are 0.8 l/kg.minute and 1.2 l/kg.minute. Parameters monitored during composting such as, temperature is done every day, pH and C/N is every week. Upon the completion of composting which is 42 days, compost is characterized to define the quality of compost and compare with SNI 19-7030-2004. The composting with aeration treatment of active and passive aeration does significantly affect the value of C/N and the different initial C/N value composition significantly affect the value of C/N by anova statistic. The compost, in physically, pH value and potassium content does meet the requirements of the compost, but it does not meet the requirements in water content, phosporus content and C/N Value, based on SNI 19-7030-2004.C/N value of the compost is 23.44 and water content is 54.56%
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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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