Karakterisasi Produk Biosolubilisasi Lignit Oleh Kapang Indigenus Dari Tanah Pertambangan Batubara Di Sumatera Selatan

Characterization of Lignite Biosolubilization Products by Indigenous Moulds from Soil ofCoal Mining in South Sumatera. Biosolubilization of coal is a potential technology of convertingsolid coal to liquid fuel and chemicals at ambient condition. Our previous research hassuccessfully isolated four moulds from soil at coal mining - South Sumatera and has potency aslignite biosolubilization agent, i.e. T1, T2, T4, T5. The objective of this research was to characterizeof lignite biosolubilization products by four isolates. The method used was sub-mergedculture. Cultivation medium was MSS+ (minimal salt + sucrose 0,1% + yeast extract 0,01% +lignite 5 %). Incubation was conducted at room temperature for 28 days. The result showed thatall indigenos moulds have different ability in lignite biosolubilization. The highestbiosolubilization occurred after 7 days of incubation belonging to T1 isolate. However, GC-MSanalysis showed the largest percentage of hydrocarbon compound which equivalent to gasolineand diesel was T5 after 7 days of incubation

Analysis properties of rock mechanics in JIIPE area, Gresik, East Java, Indonesia for tunnel construction using deformation methods in Matlab application

JIIPE Gresik’s Industrial Area, East Java, Indonesia is located in Randublatung depression zone, which is rich of sedimentary rock. In this study, we use two samples sedimentary rock (samples K2 and K5) that have been coring before. We have did calculate dimensions (diameter, height, and mass); axial deformations; transversal deformation of samples K2 and K5 used to determine stress’s value when the rock samples have been fractured and calculated modulus elasticity, so that we can analysis strength of the rock samples can use for raw material of tunnel construction. In this study, we use “versa tester” and “dial gauge” to give compression stress for rock samples K2 and K5 and we got the stress value: 0.937131 MPa rock samples K2 had been fractured, and when the stress value: 0.867409 rock samples K5 had been fractured. Also in this study we got value modulus elasticity of rock samples K2 is 10.13370616 MPa and value modulus elasticity of rock samples K5 is 24.30410248 MPa. After we compared with theoritical value from modulus elasticity of rock and soil, we can know the rock samples K2 is soft clay and rock samples K5 is medium clay. The theoritical value from modulus elasticity of soft clay is 4.1-20.4 MPa and medium clay is 20.7-41.4 MPa. In this paper, next we got curve about stress, strain, and modulus elasticity use MATLAB Apllication. As we can know, clay can’t use for raw material of tunnel construction because of the swelling clay process, properties of its elasticity that is easy to had been fractured and their value of modulus elasticity stated if rock samples K2 and K5 relatives had low strength. However, clay can use for additional material for tunnel construction (cement)