Evaluasi Penggunaan Pompa Terhadap Air Limpasan Kolong Lama Tahun 2014 Pada Tambang Besar 1.42 Pemali PT. Timah (Persero), Tbk Bangka Belitung

Tambang Besar 1.42Pemali PT. Timah (Persero), Tbk yang berlokasi di Pemali, Bangka Belitung merupakantambang timah dengan metoda Tambang Terbuka. Sistem operasi penambangannya menggunakan sistem shoveland truck. Pengolahan Awal menggunakan sistem hydroliking dan jigging. Tujuan penelitian adalah untukmengetahui jumlah air yang masuk sesuai dengan sump yang tersedia sehingga diperoleh jumlah pompa yangsesuai dengan kemajuan tambang pada tahun 2014 s.d. 2015. Total luas pit yang diprediksi dalam area TambangBesar 1.42 Pemali pada tahun 2014 sebesar 3,4 Km2 dengan luas total catchment area 0,69 Km2. Luas inidibebankan pada satu kolam penampung sementara yaitu sump lama dimana digunakan 2 pompa yang dipasangseri. Analisa yang dilakukan terhadap peta rencana operasi penambangan 2014 menunjukkan, ternyata daerahsump lama akan dilakukan penambangan. Hal ini dikarenakan di lapisan bawah sump terdapat bijih timah yangekonomis. Berdasarkan hasil penelitian ini direkomentasikan untuk melakukan penambahan 2 unit pompadengan debit 200 m3/jam agar sump dapat kering sesuai rencana. Penambahan ini diharapkan dapat mendukungoperasi penambangan secara optimal sesuai dengan rencana teknis penirisan tambang pada area Kolong Lama

Reliability, availability, maintainability and safety (rams) in railway’s assurance system and implementation challenges : A Review

RAMS forms an integral part of railway’s system assurance. It integrates reliability engineering, availability or performance calculation, maintenance strategies and system safety. While RAMS is widely implemented in other industries like petroleum, aviation and chemical, the practice in railway is relatively new. RAMS task needs to be implemented from earliest phase of system design, tendering, project execution, operation up to decommissioning. Due to its compulsory extensive involvement of railway personnel as well as authorities, RAMS is not being fully utilized as an assurance tool in railway industry. This paper will introduce the core components of RAMS and their stakeholder

Study of Diesel-biodiesel Fuel Properties and Wavelet Analysis on Cyclic Variations in a Diesel Engine

Continuous searching in new energy sources has been a crucial issue for sustaining the increasing energy demand. Due to the present economic and social modernization as well as petroleum oil depletion crisis, makespromising alternatives such as renewable energy sources an important choice for the next power generation. Petroleum fuel includesdiesel currently used in power generation, transportation, and industrial sectors. The introduction of biodiesel as a secondary fuel for diesel engines has revolutionized the use of different fuels with fuel blending in current diesel. Though biodiesel-diesel fuel can substitute diesel fuel at an acceptable blending ratio rate up to 20%, fuel properties could be affected with beyond the limit from the engine manufacturer's standard when blending at high volume ratio. Thus, in the present study, the use of the diesel-biodiesel fuel (B20) was investigated corresponding to the fuel properties and engine cyclic variations. Also, the tested fuels include mineral diesel were tested experimentally in a diesel engine with the in-cylinder pressure data measurement for 1000 cycles. These data were analyzed using the coefficient of variation (COV) and wavelet power spectrum (WPS). Fuel properties test results showed significant differences in density and acid value with a significant reduction in viscosity when diesel is blended with biodiesel at 20%. Despite that, the low heating value was significantly affected for B20 compared to pure biodiesel. While as for the wavelet analysis results, the short period oscillations appear periodically in pure biodiesel and mineral diesel, but in contrast, the long and intermediate-term periodicities has are found in B20. Moreover, the spectral power has increased with B20, which attributed significantly to the engine cyclic variations. This characteristic validated the coefficient of variation (COV) for the indicated mean effective pressure (IMEP) time series that B20 produces the lowest fluctuation in cyclic variations compared to other fuels

Reliability, availability, maintainability and safety (RAMS) components and potential: A review

RAMS implementation in Railway System is still developing and caught the attention of many researchers and institutions. The information about application of RAMS in other industries such as petroleum, chemical and avionic is already matured and widely implemented. The discussion and publication of railway RAMS need to be encouraged and continued. As railway authority started to make RAMS analysis compulsory for all phase of railway life cycle, it is important to bundle and address the component together rather than as individual discipline. This paper extracts all the important components an equation regarding RAMS