Judul: Hubungan Sifat Kimia Tanah dengan Kandungan Residu Organoklorin pada Tanah Sawah Irigasi di Jawa Barat
Abstrak: This research aims to analyze the relation of soils chemical caracteristics @th organochlorine residue of up land soils irrigations in West Java. The eight ~ils sample from up land soils irrigations in West Java (Sukabumi, Gamt, itajalengka, Sumedang, Cirebon, Subang, Karawang and Bogor) were analyzed ~r organochlorine residue on Gas Chromatograph (GC) equipped with electron $ pture detector (ECD), using capillary column. The research result showed that ~.DT and aldrin residue founded at all samples with its concentration is 0.0035- ® 073 ppm for aldrin, and 0.0015-0.0182 ppm for DDT. Lindane residue was not fOunded in all of sampels but heptachlor founded just in three soils sampel from farawang, Sumedang, and Bogor with its concentration is 0.0003-0.0065 ppm. ~il chemical caracteristics analyzed are pH, organic matter (CIN ratio), and !aYs percentage. The results showed that the range of soil pH is between 5-8, QN ratio is 4.15 until 8.47, and clays percentage is 27.43 % - 85.06 %. It was i!terested that the soil sample from Karawang showed the highest concentration <J DDT and aldrin residue. Additionally the organic matter (CIN ratio) is high @d clays percentage is 74.41 % with the result indicated that soils tecture is clay. ~atistic test with Pearson Correlation methods showed that correlation of clay tto) and DDT is 50,8%; CIN ratio and DDT is 59,1%; pH and DDT is 55,6%. ~rrelation of clay (%) and aldrin is 11,1%; CIN ratio and aldrin is 47,5%; pH and aldrin is 18,1%.
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Judul: Analisis Residu Klorpirifos pada Tanah Aluvial Setelah Penanaman Bawang Merah di Brebes
Abstrak: The application of pesticides by shallot fanners in Brebes generally was very intensive, either dosage or the frequency of application. The use of certain pesticide intensively in the agriculture has left a residue of pesticide in the plant and polluted the environment especially in the soil, surface water and ground water. In the environmental pollution, the persistency of active substance of pesticide plays very important role. This research was aimed to investigate the residue concentration of pesticide which belongs to organophosphate group in Alluvial soils after shallot cultivation in Brebes, Central Java. One of such pesticide is Dursban which has Chlorpyrifos as active substance. Another objective of this research was to study the pattern of relationship between soil characteristics and the residue of pesticide in Alluvial soils. I The results of the research showed that all soils in the study area contained high concentration of Chlorpyrifos residue, ranged between 0.39 - 0.72 mg/kg soil. Simple regression analysis showed there was a significant correlation between total Dursban application and total land area with Chlorpyrifos residue in the soil (r2= 0.76 and r= 0.70). This indicated that the bigger the area was used, and so the use of the Dursban, therefore caused the high concentration of Chlorpyrifos resiJue in the soil. There was no relationship between pH, C-org and Clay content with the Chlorpyrifos residue in the soil (r2= 0.24; r= 0.37; and r2= 0.20). Although there was no significant correlation, however, there was a tendency that increasing soil pH will cause decreasing of the Chlorpyrifos residue in the soil. High soil pH will cause the degradation of Chlorpyrifos by action of hydrolysis. Organic matter and clay content also tend to affect the concentration of Chlorpyrifos residue in the soil. High content of organic matter will suppress the volatilization of the pesticide and high clay content play in the absorption process
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Judul: Konstruksi aritmetika kurva eliptik F(2m) supersingular dan non-supersingular untuk skema kunci publik ElGamal
Abstrak: Algoritme ElGamal adalah salah satu algoritme kunci publik dengan aritmetik modular p yang mempunyai struktur grip siklik Z(p). Tingkat keanaman algoritme ini terletak pada pemecahan masalah logaritme diskret dari Z(p). Akan tetapi, tingkat keamanan tadi tahun ke tahun semakin menurun yang disebabkan kemampuan pemecahan algoritme diskret semakin meningkat. Untuk memenuhi tingkat keamanan yang memadai dibutuhkan p yang cukup besar yang menyebabkan proses enkripsi dan dekripsi menjadi lambat.
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