Judul: NPK 10-10-10 Fertilizer Formulation from Phosphate Rock, TSP, Urea, ZA and ZK using Bulk Blending Method
Abstrak: Pertanian merupakan sektor kunci pendukung perkembangan kehidupan manusia. Lahan pertanian semakin langka akibat perubahan penggunaan lahan maupun berkurangnya lahan subur yang sesuai untuk pengembangan pertanian. Kondisi tersebut mendorong pengembangan intensifikasi pertanian yang diantaranya berkaitan dengan pupuk. Saat ini produksi pertanian sangat tergantung pada penggunaan pupuk. Penelitian ini bertujuan memformulasi pupuk NPK 10-10-10 dengan metode bulk blending dan mengkarakterisasi sifat kimianya. Percobaan formulasi menggunakan Rancangan Acak Lengkap (RAL) dengan uji lanjut Duncan pada taraf kesalahan 5%. Hasil penelitian menunjukkan proses formulasi pupuk NPK 10-10-10 berbahan dasar FA, TSP, urea, ZA, ZK dan gipsum sebagai filler dengan metode bulk blending dapat dilakukan dengan baik. Sumber dan komposisi bahan baku mempengaruhi warna dan kualitas pupuk yang dihasilkan. Sumber N (urea dan ZA) tidak berpengaruh nyata pada kadar N-total pupuk NPK. Sumber P (TSP dan FA) berpengaruh nyata pada kadar P larut air, tetapi tidak berpengaruh nyata pada kadar P-total dan P larut asam sitrat 2%. Pelarut untuk penetapan total N, total P dan P potensial tersedia tidak dapat menghasilkan pembeda untuk menilai kualitas pupuk, akibat perbedaan bahan baku pupuk. Pelarut air dapat digunakan untuk pembeda kualitas pupuk terutama ketersediaan P dari pupuk. Hanya kadar N-total pupuk yang tidak memenuhi ketentuan SNI 2803:2012. Sifat tidak kompatibel antara urea dan TSP tidak dijumpai dalam formula NPK 10-10-10 ini dan pemanasan sampai 50 °C selama 24 jam tidak meningkatkan kadar biuret secara berlebihan., Agriculture is a key sector supporting the development of human life. Agricultural land is increasingly scarce due to land use change and a reduction in fertile land suitable for agricultural development. These conditions encourage the development of agricultural intensification, including its related to fertilizer. Currently agriculture is heavily dependent on fertilizer usage. The research aims to formulate NPK 10-10-10 fertilizer using the bulk blending method and characterize its chemical properties. Completely Randomized Design with Duncan's advanced test at the 5% error level used in the formulation trial. The research results showed that the NPK 10-10-10 fertilizer formulation process based on FA, TSP, urea, ZA, ZK and gypsum as filler using the bulk blending method could well be carried out. The source and composition of raw materials affect the color and quality of the fertilizer produced. The N source (urea and ZA) had no significant effect on the total N content of NPK fertilizer. Source of P (TSP and FA) had a significant effect on water soluble P content, but had no significant effect on total P and 2% citric acid soluble P content. Solvent for determining total N, total P and available potential P could not give a distinction effect for assessing fertilizer quality, due to differences in fertilizer raw materials. Water solvent could be used to differentiate fertilizer quality, especially the availability of P from fertilizer. Only the total N fertilizer content did not match the requirements of SNI 2803:2012. Incompatibility between urea and TSP was not found in this NPK 10-10-10 formula and heating to 50 °C for 24 hours does not increase the biuret content excessively.
Keyword: bulk blending, formulation, NPK

Judul: Formulation of NPK 10-10-10 Fertilizer from Oil Palm Empty Fruit Bunch Ash
Abstrak: Pupuk merupakan material organik atau mineral mengandung hara tanaman untuk mendukung pertumbuhan dan perkembangan tanaman. Produksi pupuk di Indonesia masih lebih kecil dari kebutuhan pupuk untuk kegiatan pertanian maupun non pertanian terutama akibat mahalnya bahan baku pupuk. Abu tandan kosong kelapa sawit memiliki kadar kalium tinggi yang berpotensi sebagai bahan baku pupuk majemuk. Salah satu teknologi pembuatan pupuk majemuk paling sederhana adalah blended fertilizer, yaitu pencampuran fisik kering dari berbagai bahan pupuk dengan komposisi tertentu. Tujuan penelitian ini adalah memformulasi pupuk NPK 10-10-10 melalui proses pencampuran (blending) kering dari abu tandan kosong sebagai bahan baku pupuk NPK dan mengetahui karakteristik serta kadar haranya. Rancangan Acak Lengkap (RAL) dengan 4 perlakuan dan diulang 3 kali digunakan dalam percobaan ini. Rancangan perlakuan menggunakan kombinasi dari bahan baku pupuk Urea, ZA, TSP, ZK, fosfat alam, abu tandan kosong, dan filler berupa gibsum. Analisis pupuk meliputi kadar air, kadar N-P2O5-K2O total, kadar P2O5-sitrat 2%, kadar P2O5 dan K2O larut air, cemaran logam (Pb, Cd, As, dan Hg), dan kadar biuret. Data hasil percobaan disidik ragam dan diuji lanjut dengan uji jarak berganda Duncan pada selang kepercayaan 5%. Pupuk NPK 10-10-10 yang dihasilkan dari proses pencampuran (blending) kering berbentuk granul dengan warna abu-abu terang hingga kehitaman. Komposisi bahan baku pupuk berpengaruh nyata terhadap kadar N-P2O5-K2O total serta kadar P2O5-sitrat 2%, P2O5 dan K2O larut dalam air. Kadar hara (N, P2O5, dan K2O), kadar air, dan cemaran logam pada pupuk NPK 10-10-10 memenuhi syarat SNI 2803:2012dengan batas toleransi maksimal 8% di bawah formula. Formula NP1K1 merupakan formula pupuk terbaik berdasarkan total kadar hara N, P2O5, K2O serta kelarutan P dalam asam sitrat dan air. Kadar biuret formula NP1K2 dan NP2K2 memenuhi syarat SNI 2801:2010., Fertilizers are organic or mineral materials containing nutrients that are important to support plant growth and development. Fertilizer production in Indonesia is not enough to full fill fertilizers requirement for agricultural and non agricultural activities. Oil palm empty fruit bunch ash has a high potassium content that has potential as a raw material for compound fertilizer. One of the simplest compound fertilizer manufacturing technologies is blended fertilizer, which is the dry physical mixing of various fertilizer materials with a certain composition. The purpose of this research is to formulate NPK 10-10-10 fertilizer through bulk blending process from empty fruit bunch ash as raw material and to determine its characteristics and nutrient content. A completely Randomized Design with 4 treatments and repeated 3 times was used in this trial. The trial design used combinations of fertilizer raw materials as Urea, ZA, TSP, ZK, rock phosphate, empty fruit bunch ash, and gypsum as a filler. Fertilizer characterization analysis included moisture, total N-P2O5-K2O, P2O5-citrate 2%, water soluble P2O5 and K2O,metal contamination (Pb, Cd, As, and Hg), and biuret content. Data of the trial were subjected to F-tested and Duncan's multiple range test at 5% confidence interval. Result of the trial showed that NPK 10-10-10 fertilizer by blending process have a light gray to blackish color. The composition of fertilizer raw materials has a significant effect on the total N- P2O5- K2O as well as the P2O5-citrate 2%,
Keyword: empty fruit bunch ash, dry blending, NPK fertilizer

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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