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: 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: 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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