Judul: Design of Co-composting Process and Nano Technology to Handling of Solid Waste of Sugar Industry
Abstrak: Sebagaimana agroindustri lainnya, industri gula tebu memiliki tantangan besar dalam pemanfaatan yang tepat dari limbah padatnya, yaitu bagas, blotong dan abu ketel. Bagas telah banyak digunakan secara luas sebagai bahan bakar saat produksi gula, dan sisanya digunakan sebagai pakan, pupuk organik, pulp, papan partikel, dan kanvas rem. Pemanfaatan bagas lainnya yang sedang dikembangkan adalah pembuatan amylase, asam sitrat, dan selulosa asetat. Blotong dimanfaatkan juga sebagai bahan produksi kompos (bersama-sama dengan abu ketel) dan juga sebagai briket bahan bakar. Abu ketel memiliki potensi dalam produksi gel silika, As of other agro-industries, sugarcane industry has also a major challenge in the proper utilization of its solid waste, namely, bagasse, filter cake, and boiler ash. In practice, bagasse has been used extensively as feed for boiler for sugarcane processing, however, the rest is usually used for animal feed ingredients, organic fertilizer, pulp, particle board, and brake pad. Advanced technique has also been developed for production of chemicals such as amylase, citric acid and cellulose acetate from the bagasse. Filter cake, has been used for the production of compost (either solely or mixed with boiler ash), and has also been compacted into briquettes for fuel. The boiler ash, while is less interesting to use, has also had a potential use in the production of silica gel.
Keyword: Baggase, filter cake, Broiler ash, co-composting, Nanosilica, B/C ratio, Solid waste, Sugarcane industrial, Organic fertilizer

Judul: Proses Co-composting Bagas dan Sludge dari Industri Gula dengan Pengaruh Perbedaan Nilai C/N Awal dan Aerasi
Abstrak: Bagasse and sludge are solid waste of sugar industry which contained high organic material and have not been used optimally. The purpose of this research was to utilize bagas and sludge of the sugar industry through co-composting technology for making organic fertilizer and determine the influence of aeration and materials concentration on the value of C/N. Bagas and sludge combination were composted at C/N value of 30, 40, and 50. In composting process, aeration rate set on 0.4 l/minute.kg and 1.2 L/Kg of dry basis materials. The research was carried out two stages, that was preliminary research, it was determined composition of raw materials mixture, and primary research for determining C/N value during composting. Parameters monitored during composting were temperature done every day, pH and C/N determined every week. The result showed that aeration treatment did not give noticeable effect on C/N value and compost with initial C/N value of 30 gave the fastest decomposition process in co-composting stages
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Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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