Judul: Analisis Bioakumulasi Timbal (Pb) Pada Ikan Nila Merah (Oreochromis nilotica) dan Patin Jambal (Pangasius djambal) yang Dibudidayakan di Kolong Tua pasca Tambang Timah Bangka Belitung
Abstrak: The consequences of tin mining activity is the formation large basin-shaped holes filled with water in which the local (Bangka Belitung islands) term is a Kolong or Camuy (lake). Heavy metal concentrations are still high in all the pit and endangering human health; is the image that is in today's society so that people refused to eat the fish from or doing aquaculture activities in kolong. The study was conducted from October 2011 to February 2012 in Kolong Grasi, District Sungailiat Bangka Regency, Province of Bangka Belitung Archipelago at coordinates S01052.464 '; E106007.005. Chemical analysis carried out at the Laboratory of Industrial Technology of Agricultural, Aquaculture Environmental Laboratory, Fish Nutrition Laboratory, IPB. Materials used in this study are meats, gills, liver and kidneys of red tilapia and jambal catfish. Organ samples taken each month from October 2011 to February 2012. Chemicals for testing heavy metal Pb is the standard solution at a concentration of 1000ppm Pb from BDH, concentrated nitric acid from Merck and distilled water. The equipment used is the pH meter, DO meter, analytical neraca, a ruler, a set of surgical instruments, two units of floating net cage with the dimension 3m x 3m x 2m of each, and pH-meters, a set of Atomic Absorption Spectrometry tools (AAS) AA 300 P type from Varian Techtron Australia, 50ml beaker glass, 10 ml volumetric flask, 5ml vial size polyethylene, 10-100mL effendorf micro pipettes, analytical balance, furnace, hot plate, Mercury Vaporise Unit (MVU) and other glassware equipment used in labs. The study began with measurements of heavy metals lead (Pb) in water and sediment once at the beginning of the study. Measurement of water quality include physical parameters are: temperature, pH, brightness, and chemical parameters including DO, CO2. Measurements were made directly in the field. Measurement of chemical parameters such as: Total Organic Matter (TOM) and Pb performed in the laboratory at the beginning of the fish culture period and then performed each month at the site of cultivation. Measurement of Pb content in the sediment is also done once in the early of the study. All data was analyzed using the comparison of two mean values (t-test). The results of gut contents identification of fish are presented in tabulated and all the relationships described in the descriptive parameters. Physico-chemical quality of water in Kolong Grasi is ideal for red tilapia aquaculture and jambal catfish. Several parameters such as temperature, brightness decreased and increased levels of TOM in January 2012 and did not occur in previous months dueto the rainy season in January 2012. Pb heavy metal content in the red tilapia was found in the first month of cultivation, the month of November is 0,085μg/g in liver. In the third month (January 2012), lead is found in almost every organ of red tilapia and exceed safe levels for consumption, ie 8,41 μg/g in the gills, 93,98 μg/g in kidney, 62,14 μg/g in the liver and undetectable in meat. Accumulation of the heavy metal in the meat of red tilapia is found 0,188 μg/g in the mont of fourth (February 2012). The highest
Keyword: 

Judul: Heavy Metal Content of Fe, Pb in Water and Tilapia (Oreochromis niloticus) in Cinangka Village, Bogor District
Abstrak: Perairan yang tercemar oleh logam berat akibat aktivitas antropogenik sangat memungkinkan terakumulasi ke dalam tubuh biota seperti ikan nila (Oreochromis niloticus) yang terdapat di wilayah perairan sekitar Desa Cinangka. Penelitian ini bertujuan menganalisis bioakumulasi kandungan logam berat timbal (Pb) dan besi (Fe) pada ikan nila serta hubungannya dengan kualitas air. Pengambilan sampel dilakukan sebanyak tiga kali pada bulan September 2020. Titik sampling yang dipilih adalah kolam pemancingan ikan yang terdapat di Desa Cinangka. Analisis konsentrasi logam berat dilakukan dengan menggunakan metode Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). Parameter kualitas air kolam pemancingan Desa Cinangka masih sesuai dengan baku mutu. Hasil pengukuran kandungan logam Pb pada daging ikan nila berkisar antara 0,32 mg kg-1 hingga 0,4 mg kg-1 dan kandungan logam Fe sebesar 2,18 mg kg-1 hingga 3 mg kg-1. Faktor biokonsentrasi logam Pb termasuk kategori tinggi dan logam Fe termasuk kategori rendah hingga sedang. Waktu pengambilan sampel yang dilakukan tidak berpengaruh secara signifikan terhadap akumulasi logam berat pada ikan nila. Kata kunci: Bioakumulasi, Desa Cinangka, logam berat, Oreochromis niloticus, Waters polluted by heavy metals due to community activities are very likely to accumulate in the body of organism such as tilapia (Oreochromis niloticus) found in the waters around Cinangka Village. This study aims to analyze the bioaccumulation of lead (Pb) and iron (Fe) in tilapia and their relationship with water quality. Sampling was carried out three times in September 2020. The selected sampling point is a fishing pond in Cinangka Village. Heavy metal concentration analysis was carried out using the Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) method. Parameters of water quality of Cinangka Village fishing pond still in accordance with quality standards. The results of measurements of Pb metal content in tilapia ranged from 0.32 mg kg-1 to 0.4 mg kg-1 and Fe metal content was 2.18 mg kg-1 to 3 mg kg-1. Bioconcentration factor of Pb is high category and Fe metal is low to medium category. The sampling time was not significantly affected by the accumulation of heavy metals in tilapia. Keywords: Bioaccumulation, Cinangka Village, heavy metals, Oreochromis niloticus
Keyword: Bioaccumulation, Cinangka Village, heavy metals, Oreochromis niloticus

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
Keyword: