Judul: Pengaruh Pemberian Blast Furnace Slag, Electric Furnace Slag, Dolomit dan Silica Gel terhadap Sifat Kimia Tanah Gambut Dalam dari Desa Arang-Arang Jambi
Abstrak: Peat soil is soil having layers consisting high of organic materials (C-Organic > 18 %) whitin the thickness 50 cm or more. Organic materials of peat soil is formed by remnamt of decaying plants that have not been smashed perfecly because saturated water environmental conditions and low nutrient. Utilization of peat soil in agriculture is faced to several problems, especially chemical characteristic of the soil that is not supporting the growth of plants well. The characteristics are soil reaction which extremely acid, low base sarutation, very high cation exchange capacity and low nutrient balancing. Consequently, it is required improvements in chemical characteristic of soil such as application like steel slag. This research was purposed to investigate the effect of blast furnace slag (BF slag), electric furnace slag (EF slag), dolomite, and silica gel on chemical soil properties of peat soil and the availability of toxic heavy metal in the soil. This research was conducted by incubation experiment in laboratory using peat soil from Kumpeh, Jambi. Treatments applied were EF slag, BF slag 0 %, 2 %, 4 %, 6 %, and 8 %; dolomite and silica gel equivalent to EF slag 0 %, 2 %, 4 %, 6 %, and 8 %. The experimental design used was completely randomized design (CRD). The result of statistic analysis showed that BF slag, EF slag and dolomite significantly increased soil pH, and available Ca and Mg in the soil. The effect of treatments on available K and total N were not significant. EF and BF slag significantly increased available P in the soil, but dolomite and silica gel did not. EF slag treatment significantly increased available Fe in the soil, but BF slag, silica gel and dolomite did not. Dolomite and silica gel did not increase available Mn in the soil, but EF and BF slags significantly increased. Result of available Cu analysis indicated that among treatments only silica gel 8% increased available Cu in soil. EF slag and silica gel treatments increased Zn in the soil, but BF slag and dolomite treatment did not. EF and BF slags significantly increased available SiO2 in the soil, while dolomite and silica gel did not. The result of the heavy metal analysis showed that all treatments significantly reduced available Pb and Cr in the soil, but did not reduce available Cd and Hg in the soil.
Keyword: heavy metal levels., Nutrient level, Silica gel, Dolomite, Slag, Peat

Judul: Pengaruh Residu Electric Furnace Slag, Blast Furnace Slag dan Unsur Mikro terhadap Sifat Kimia Tanah serta Pertumbuhan dan Produksi Padi Sawah Tanaman Kedua pada Tanah Gambut
Abstrak: Steel slag is a by-product formed in the process of steel manufacturing. Electric Furnace Slag (EF slag) and Blast Furnace Slag (BF slag) are two examples which were used in this research. Steel slag can be used as soil ameliorant. As soil ameliorants, EF slag and BF slag were able to improve chemical properties of peat soil, resulting in enchantment of growth and paddy rice yield of IR 64 on first plant. Toxic heavy metals content was below acceptable limit for rice produced. The objectives of this experiment were to evaluate residual effect of EF slag, BF slag and micro nutrient on chemical soil properties and growth and yield of paddy rice on peat soil as second plant. The results showed that residue of EF slag and BF slag significantly increased soil pH, exchangeable Ca and Mg. Residue of EF Slag and BF slag significantly increased SiO2 and micro nutrients (Fe and Mn). Growth and yield of paddy rice with residue of EF slag were significantly better than those of BF slag. Toxic heavy metals (Pb, Cd, As, dan Hg) in rice were below acceptable limit for rice product. So that rice produced on EF slag and BF slag is save for consumer.
Keyword: Peat, BF slag, EF slag

Judul: Invers dari Matriks Tridiagonal Jacobi
Abstrak: Suatu matriks berukuran n×n dinamakan matriks tridiagonal jika untuk . Karya ilmiah ini memberikan algoritma yang mudah untuk menemukan invers ( dari matriks tridiagonal Jacobi yang simetrik dan nonsimetrik. Setiap elemen pada matriks tridiagonal ini adalah bilangan real. Terdapat 3 lema dan 2 teorema untuk menentukan . Lema pertama menunjukkan persamaan utama dalam membuktikan lema-lema dan teorema-teorema selanjutnya. Invers dari matriks yang simetrik dibuktikan oleh lema kedua yang menunjukkan elemen-elemen baris ke- dari . Selanjutnya, lema kedua dilengkapi dengan teorema pertama yang menunjukkan elemen-elemen dengan . Invers dari matriks yang nonsimetrik dibuktikan oleh lema ketiga yang menunjukkan elemen-elemen dengan dan elemen-elemen dengan dibuktikankan oleh teorema kedua.
Keyword: symmetric, nonsymmetric, matrix