Judul: Study Of Water Quality And Pollutant–Loaded Capacity Of Kapuas River, Pontianak City, West Kalimantan.
Abstrak: The development of West Kalimantan especially in the surrounding area of Kapuas River contributes significantly to the pollution of the river. Some measures have undertake for reducing the pollutant load entering into the river. The objectives of this study are to determine the water quality and to analyze the pollutant – loaded capacity of Kapuas River, Pontianak. Samples were taken from five different stations, along the river in Pontianak City. Results of laboratory analysis were compered to the water quality standard (PP No. 82 /2001). STORET Method was used to determine the water quality status of each sampling station. The result of laboratory analysis showed that concentrations of TDS were approximately 21 – 1233 mg/L, Hg 16.41-27.01 ppb, Ammonia 0.3 – 0.98 mg/L, BOD 3.06 – 3.99 mg/L, COD 15 – 25 mg/L and Fecal Coliform 0.1 – 12 x 105 MPN/100 ml. These results show that the water quality of Kapuas River do not meet the stated water quality standard including physical, chemical and the microbiology parameters. Water of Kapuas River is no longer proper to be used as raw water for drinking water. The study of industrial waste water shows that the waste water is treated and met the waste water standard (KepMenLH No. 51/1991). Other pollutant sources may the cause of the Kapuas River pollution. Local Government Policies should be undertaken immediately to solve the pollution problem of Kapuas River, because the water of the river is nowdays used as raw water of PDAM in Pontianak.
Keyword: 

Judul: Assessment on Heavy Metals (Hg, Cd, and Pb) Contamination in Kapuas Estuary Waters, West Kalimantan
Abstrak: Various activities of the communities along the Kapuas River in West Kalimantan, such as domestic, transportation, harbor, and industries have an impact on the environment through waste water. Illegal gold mining in the upstream region also contributed to the decline in the quality of the Kapuas River. The existence of toxic metal in water and sediment could threaten the environmental health of the Kapuas Estuary through the process of bioaccumulation and biomagnification in the food chain, and threatens the sustainability of marine fishery products eventually. The availability of accurate data on the condition of the waters of the Kapuas Estuary is absolutely necessary. This is particularly useful in formulating strategic and anticipatory policies for the management of the marine environment and natural resources in the coastal areas of West Kalimantan. This study aims to determine the concentration and distribution of Hg, Cd, and Pb in the Kapuas Estuary as information for integrated management of the coastal marine environment in West Kalimantan. This research was conducted in April and September 2011 in the Kapuas River and coastal waters of the Kapuas Estuary with 20 sampling stations. Analysis of dissolved Hg refers to SNI 19-6964.2-2003, whereas analysis of dissolved Cd and Pb refers to Standard Methods for the Examination of Water and Wastewater 3111C. Analysis of Hg in sediments and TSS refers to US EPA 245.5 methods, whereas analysis of Cd and Pb in sediments and TSS refers to US EPA method 3050B. Analysis of Hg in fish tissue was based on the AOAC Official Method, whereas analysis of Cd and Pb refers to ASEAN Canada CPMS II. Physico-chemical characteristics of water such as salinity, pH, dissolved oxygen, temperature, TSS concentration and sediment characteristics (grain size and organic matter content) were also measured to determine the condition of the waters at the time of sampling. Physico-chemical characteristics of the Kapuas Estuary is characterized by a range of salinity between 0-31 psu. pH values varied between 3.24-5.11 in the Kapuas River, and 5.82-8.21 in coastal areas. Temperatures in the Kapuas River basin ranged from 28.4-30.0 °C, while in coastal areas varied between 21.1-32.2 oC. Dissolved oxygen concentration in the Kapuas River basin ranged from 4.74-5.60 mg l-1, while in coastal areas ranged from 4.5-6.8 mg l-1. Total suspended solids (TSS) had variation of the concentration between 56.90-107.80 mg l-1 in the Kapuas River, and 16.50-230 mg l-1 in the coastal areas. Dissolved Hg concentrations in the Kapuas River basin ranged from 0.05 -0.49 mg l-1, while in coastal areas ranged from <0.001-0.80 mg l-1. Hg concentrations in TSS in the Kapuas River basin ranged from 1.00-2.59 mg kg-1 dry weight, while in coastal areas varied between 0.20-4.01 mg kg-1 dry weight. Dissolved Cd concentrations ranged from 0.05-0.63 mg l-1 in the Kapuas River, and <0.001-0.73 mg l-1 in the coastal areas. Cd concentrations in TSS in the Kapuas River basin ranged from 21.66-69.33 mg kg-1 dry weight, while in coastal areas varied between 3.18-85.37 mg kg-1 dry weight. The concentration of dissolved Pb in the Kapuas River basin ranged between 2.15-3.44 mg l-1, while in
Keyword: pollution, heavy metals, water, sediment, fish, Kapuas Estuary

Judul: Grup dan Homomorfisma Grup pada Rubik Revenge
Abstrak: Rubik cube is a kind of puzzle game. A player must arrange rubik sides, which have been disordered, back to the position where every side has the same colour. This paper does not focus on the settlement solution, but instead on proving the existence of a group homomorphism between rubik movement group and S96 symmetric permutation group in rubik revenge. Firstly, it has been proved that rubik movement set is a group. Then, it also has been proved that the M set, which contains numeric labels of 1 until 96 in cubinos sides, is S96 symmetric permutation group.
Keyword: