Judul: Model of water pollution control on Surabaya River Region
Abstrak: The Surabaya River plays an important role as water supply of the Surabaya PDAM, irrigation, industry, transportation, and means of recreation. However, domestic, industrial, and agricultural waste that were discharged into the river stream polluted the Surabaya River and decreased the carrying capacity and assimilative capacity. Therefore, effort to monitor and control the Surabaya River water pollution need to be well organized and implemented. The aim of the research is to develop a model of water pollution control on Surabaya River region. The research was conducted in five steps, i.e. (1) determine the existing condition of physical and chemical parameters, (2) determine the load pollution and level of pollution, (3) determine the priority of reduction activities of loading pollution and technology control, (4) build dynamics model of water pollution control, and (5) formulate policies or scenarios of water pollution control of the Surabaya River. The research was carried out based on field survey, in situ and laboratory sample examination, questionnaire, and expert judgement. The loading pollution was determined by rapid assessment. The STORET method and pollution index were used to determine the water quality status and level of water pollution. Analytical hierarchy process (AHP) and comparative performance index (CPI) were used to determine the priority of reduction activities and technology control. Pollution control model developed in this study was built into three sub-models, namely: (1) ecology sub-model, (2) social sub-model, and (3) economy sub-model using powersim constructor 2.5 version. Pollution control scenarios were developed using prospective analysis. The results of water pollution parameters such as total suspended solid (TSS), dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), nitrite (N-NO2 Keywords: pollution control, prospective analysis, surabaya river, system approach ), and the level of mercury (Hg) were higher than the allowable class 1 standard. The sources of Surabaya River pollution mainly are domestic and industrial waste with total load of BOD, COD, and TSS are 55.49, 132.58, and 210.13 ton/day, respectively. According to water quality status, the Surabaya River is categorized as heavy polluted and the loading pollution need to be decreased. Simple management and efficiency are mainly criteria for reduction activities of loading pollution with determining water class as top alternative following with illumination and calculated the carrying capacity toward water pollution load. The wastewater garden, filtration, screening, and biofilter are priority of technology control in sequence. By using prospective analysis, there were five important factors that affect the future of the Surabaya River water pollution control, i.e.: (1) population growth and community awareness, (2) community perception, (3) implementation of regulations, (4) commitment/local government support, and (5) system and institutional capacity. There are three development scenarios, that are pessimistic, moderate and optimistic. The moderate and optimistic scenario are the realistic scenarios that occur in the future for Surabaya River water pollution control in considering of ecology, social and economy aspects.
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Judul: Kajian Peningkatan Kualitas Air Sungai Ciujung Berdasarkan Parameter Senyawa AOX (Adsorbable Organic Halides) dengan Model WASP (Water Quality Analysis Simulation Program) dan Model Dinamis
Abstrak: Ciujung River was the largest river in Banten Province with watershed area 1,935 km2 and 147 km length. The upstream of Ciujung River was located in Lebak Regency and the downstream was in Serang Regency. The river plays important role for Serang Regency for domestic, agricultural and industrial activities. At present, Ciujung River has become a national issue as a river that was polluted, decreased in discharge, river siltation due to the critical land in the upstream and industrial activity in the downstream that influenced the society’s health and social economy, especially in the downstream region.The river class and total maximum dayli loads (TMDLs) has not been determined by the national and regional government, so that the water river quality of Ciujung River was defined based on the Government Regulation No. 82/2001 concerning the management of water quality and water pollution control. However, adsorbable organic halides (AOX) parameter was not included in the regulation. AOX compound was a specific pollutant that toxic, hydrophobic, carcinogenic, persistent, and could be bio accumulated in fish body so it would pose a risk to human health. If there was no effort in controlling the pollution, it could be sustained and influenced the river function. The main objective of this research was to develop a model in controlling pollution in Ciujung River with three steps, i.e. (1) analyzing AOX compound in exist condition of Ciujung River, (2) determining the priority of pollution load controlling strategy in Ciujung River, and (3) formulating a model of pollution control in Ciujung River. The research was done by field survey, sample analysis directly in field and laboratory, questionnaire distribution, and in-depth interview with the expert. Water quality was analyzed with pollution index method; TMDLs was determined with water quality analysis simulation program (WASP). Priority of pollution load controlling strategy was analyzed with analytical hierarchy process (AHP) method. Model of Ciujung River water pollution control was developed with system approach using Powersim Studio 2005. The result showed that in existing condition, most parameter in several locations did not meet the criteria of class II water quality standard. DO, pH and nitrate content met the standard in all location, whereas BOD, COD, nitrite, phenol and AOX compound did not meet the standard.Status of Ciujung river water quality according to pollution index value without AOX compound, was in status of light to moderate polluted (IP 0.32 – 7.10). Whereas by considering the AOX parameter, Ciujung River was in status of light to severe polluted (IP 1.80 – 14.04). Potential pollution load that went into Ciujung River was come from non-point source, i.e. domestic, livestock, and agricultural waste and point source, i.e industry. The increase of pollution load potential that went into Ciujung River caused decrease of TMDLs. WASP simulation result showed that in minimum reliable discharge (1.9 m3/second), Ciujung River did not have TMDLs for class II river based on BOD (-3,470 kg/day) and AOX compound (-5 kg/day). The analysis result of priority strategy in controlling pollution in Ciujung River using AHP showed that three alternatives priorities need to be done to control the
Keyword: Bogor Agricultural University (IPB)

Judul: igenvalues and Eigenvectors of Tridiagonal Matrix with Non Constant and Recurrent Diagonal Entries.
Abstrak: Matriks tridiagonal adalah suatu matriks yang mempunyai entri-entri bernilai nol kecuali pada diagonal utama, di bawah diagonal utama (subdiagonal) dan di atas diagonal utama (superdiagonal). Entri pada diagonal utama tidak konstan dan berulang. Setiap entri pada matriks tridiagonal ini adalah bilangan kompleks. Dalam karya ilmiah ini, akan dibuktikan 3 teorema untuk menentukan nilai eigen dengan 2 kasus dan 1 teorema untuk menentukan vektor eigen. Teorema pertama menentukan polinomial karakteristik dari matriks tridiagonal. Polinomial karakteristik dari matriks tridiagonal tersebut digunakan untuk menentukan nilai eigen pada teorema kedua dan ketiga serta menentukan vektor eigen pada teorema keempat
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