Center for Scientific Publication
Not a member yet
4029 research outputs found
Sort by
Modification of Sea Water Scrubber System into Fresh Water of Inert Gas System on the Crude Oil Tanker 85,000 DWT
Get PDFEach ship carrying a hydrocarbon must be equipped with an inert gas system. On tankers, the function of inert gas is to prevent fires or explosions caused by oxygen levels contained in cargo tanks. Inert gas is produced by cleaning the exhaust gas boiler using a sea water scrubber system. However, seawater has corrosive properties that cause the use of material in scrubber system components to be resistant to corrosion. Therefore, through this research a modification of the sea water scrubber system was made into a freshwater scrubber system. The advantages of a freshwater scrubber system include a low corrosive level that causes the use of inexpensive materials. Modification of seawater scrubber systems into fresh water causes additional components to be made, including adding NaOH tank, expansion tank of freshwater, seawater pumps, freshwater pumps, NaOH pumps, heat exchanger, and wash water treatment unit. Economic calculations are carried out to determine the installation costs and operational costs needed from this modification. Based on the technical and economical analysis, modification of the sea water scrubber system into fresh water inert gas system of Crude Oil Tanker 85,000 DWT can be done with an estimated installation cost of 1.5 Bill. Rupiahs
Metode Analisis Besi Melalui Optimasi Kemampuan Agen Pereduksi NH2OH.HCl dan C6H8N2
Get PDFPada penelitian ini dibandingkan aktivitas pereduksi NH2OH.HCl dan C6H8N2 dalam mereduksi Fe3+ menjadi Fe2+. Variasi yang dilakukan adalah pH buffer asetat optimum, waktu pembentukan kompleks optimum, dan konsentrasi pereduksi optimum dalam penentuan kadar besi (Fe) dengan menggunakan spektrofotometer UV-VIS. λmaks kompleks [Fe(C12H8N2)3]2+ dengan menggunakan pereduksi NH2OH.HCl dan C6H8N2 sebesar 510 nm. Penentuan pH buffer asetat optimum dengan pereduksi NH2OH.HCl diperoleh pH 4,5 dan pereduksi C6H8N2 diperoleh ph 3. Penentuan waktu pembentukan kompleks optimum dengan pereduksi NH2OH.HCl diperoleh pada waktu 15 menit dan pereduksi C6H8N2 diperoleh pada waktu 30 menit. Selanjutnya, dilakukan penentuan konsentrasi optimum dengan pereduksi NH2OH.HCl didapatkan pada 8 ppm dan pereduksi C6H8N2 didapatkan pada 80 ppm untuk mereduksi 5 ppm larutan Fe3+. Hasil %recovery yang diperoleh dari pereduksi NH2OH.HCl dan C6H8N2 secara berturut-turut sebesar 95,126% dan 153,090%
Route Optimization of Oil Country Tubular Goods Distribution Using Sweep and Savings Algorithm
Get PDFIn the oil and gas industry, one of the key activities is the drilling process where the oil or natural gas are extracted. The process requires the supply of rolled products known as the Oil Country Tubular Goods (OCTG). As an important drilling component, OCTG has a high demand, which in some case it is not balanced with the optimal distribution route and cost that may affect the industry’s profit. In order to obtain the optimal distribution routes, this research compares transport routes generated by Sweep and Savings Algorithm to solve the Capacitated Vehicle Routing Problem, by taking an oil and gas company with inefficient OCTG distribution in Sumatera as the object of the study case. Additionally, the total transportation cost is calculated to further compare the results. The research concludes that Sweep Algorithm produces the most efficient routes with the lowest total transportation cost of Rp.18,890,875,000 per year, or 24% less than total cost derived from Savings Algorithm route
Cost-Benefit Analysis of POME Biogas Power Plant: Case Study of PLTBg Suka Damai
Get PDFPalm Oil Mill Effluent (POME) is a byproduct of processing fresh palm fruit bunches into crude palm oil (CPO) which has negative externalities in the form of gas containing methane, carbon dioxide and other greenhouse gases (GHG) which is very dangerous for sustainability environment. The use of pome as feedstocks for biogas power plants (PLTBg) changes the negative externalities of pome into positive externalities such as increased electrification in the area around the palm oil mill (PKS) and also good for environmental sustainability. PLTBg Suka Damai with a capacity of 2.4 Mw is planned to reach the Commercial Operating Date (COD) in 2019, the financial calculation has a cost-benefit ratio of 1.19, percentage of Internal Rate of Return (IRR) of 12.84%, percentage of weighted cost of capital (WACC) 10% and a Net Present Value (NPV) of Rp 21,275,609,209.00. Using the cost-benefit analysis method, the authors calculate the positive externalities generated by PLTBg Suka Damai by comparing the value of benefits into three (3) alternative scenarios. The scenario I add the social cost of carbon (SCOC) as additional benefits; scenario II adds carbon credit income parameters from the REDD+ scheme; scenario III only utilizes the benefits of electricity sales and the electrification without adding additional benefits. Comprehending all the results, the first scenario with SCOC is the most optimize scenario for it provides far greater benefits to the community, far greater than the financial revenue received by the PLTBg itself
Kajian Validasi Data Global Satellite Mapping of Precipitation (GSMaP) di Bengkulu
No full textThe rainfall observation data is hard then we need other option to obtain the data which is easier and more accurate. One of methods to obtain rainfall data is using remote sensing. GSMaP is one among products produces by remote sensing which is able to obtaining rainfall data using satellite. The aim of this study is to validate the rainfall data using GSMaP to the rainfall observation data in Bengkulu for 2012-2015. The method used is processing GSMaP data into monthly data then comparing it with in situ data. In addition, there's processing data with statistical test. Based on the results, the correlation between GSMaP data and observation data is in range of 0,4 to 0,89. It shows that GSMaP data is quite valid to be used to fill incomplete rainfall data in Bengkulu, but it has not been able to intrepret value close to underforecast data
3D non-linear finite element analysis of concentrically loaded high strength reinforced concrete column with GFRP bar
Get PDFThe use of High Strength Concrete (HSC) material in Reinforced Concrete (RC) column has become widely used. HSC was found to be durable, strong in compression, but it has low ductility. This low ductility of HSC can be improved by providing confinement. However, for HSC with concrete strength higher than 70 MPa, additional clause for confinement in ACI 318-19 generates denser arrangement of transverse bars and eventually creates weak planes between the concrete core and the cover. These weak planes can trigger early cover spalling. To reduce the utilization of confining bars, high-strength Glass Fiber Reinforce Polymer (GFRP) bar can be used. However, the performance of GFRP bar varies significantly from their uniaxial behavior in tension or compression to the real performance when it is used as the main reinforcement. For that reason, this paper tries to investigate the behavior of HSC RC column with bars made of conventional steel rebar and with GFRP bars. Due to limited data on the strain gauge reading on the GFRP bars from the available test result, an inverse analysis is carried out to determine the best stress-strain curve for GFRP bars used as the main reinforcement. For that purpose, an inhouse finite element package called 3D-NLFEA is used. From the comparisons, it was found out that the peak load, softening behavior, and the concrete core enhancement prediction agrees well with the test result. From the inverse analysis, only 25% and 45% of the GFRP bar yield strength can be deployed when loaded under compression and tension, respectively
Pembuktian Sifat non-Hausdorff dari Grup Lie GL(n,C) Bertindak pada M(n,C)
No full textPada penelitian ini dibahas grup Lie General Linear GL(n,C) bertindak secara konjugasi pada manifold M(n,C). Himpunan semua orbit dari tindakan grup Lie tersebut dideskripsikan melalui bentuk kanonik Jordan yang merupakan ruangkuasi. Telah diduga jika X dan Y adalah matriks-matriksdi M(n,C) dengan nilai-nilai eigen yang sama tetapi memiliki bentuk kanonik Jordan yang berbeda, maka irisan dari persekitaran orbit dari Y dan persekitaran orbit dari X tidak kosong. Namun, pembuktian lengkap dari dugaan tersebut belum ada. Pada paper ini, diberikan pembuktian formal dugaan tersebut dengan perturbasi matriks, yaitu ruang kuasi yang berbentuk kanonik Jordan tersebut adalah suatu ruang non-Hausdorff
Studi Aplikasi Corporate Identity Pada Elemen Interior Kantor Telkom Indonesia
Get PDFIdentitas korporat merupakan salah satu faktor penting dalam membangun citra diri sebuah perusahaan. PT. TELKOM merupakan salah satu perusahaan besar di Indonesia yang sangat berhasil membangun sebuah citra perusahaan. PT. TELKOM memiliki citra yang sudah sangat melekat dan mudah dikenali oleh masyarakat luas. Identitas korporat juga merupakan aspek penting dalam perancangan interior, dengan tujuan untuk membuat para pengguna ruang memahami citra dari perusahaan melalui implementasi dalam setiap elemen interior. Penelitian ini mengkaji beberapa kantor PT. TELKOM yang cukup signifikan mengimplemtasikan identitas korporat dalam elemen interiornya ABSTRACT Corporate identity is one of the important factor in building a company’s self-image. PT. Telkom is one of the big companies in Indnonesia that has been very successful in building a corporate image. PT. Telkom has an image that is already very attached and easily recognized by the wider community. Corporate identity is also an important aspect in interior design, with the aim of making space users understand the image of the company through implementation in every interior element. This study examines several office of PT. Telkom, which quite significantly implements corporate identity in its interior elements. Keywords : Corporate identity, Telkom Indonesia Office, Interior elemen
EVOLUTION OF STRUCTURE, PHASE AND MECHANICAL PROPERTIES DUPLEX STAINLESS STEEL (DSS) 31803 WELDING USING GMAW WITH THE ADDITION OF CO2 TO Ar - CO2 SHIELDING GAS
Get PDFThe purpose of this study was to analyze the effect of CO2 on the composition of the Ar- CO2 shielding gas in DSS 31803 duplex welding using GMAW on carbon deposition, ferrite fraction, microstructure, weld and HAZ mechanical properties. This study uses A (100% Ar), M1 (95% Ar + 5% CO2), M2 (90% Ar + 10% CO2), M3 (85% Ar + 15% CO2), M4 (80% Ar + 20 % CO2), M5 (75% Ar + 25% CO2) and C (100% CO2). From the results of the study, the microstructure of the weld metal in each specimen contained grain boundary austenite (GBA), Widmanstätten austenite (WA), intragranular austenite (IGA), and partial transformed austenite (PTA). Scanning electron microscopy (SEM) identifies the occurrence of chrome carbide precipitation (Cr23C6) HAZ region in specimens M5 and specimen C. The equilibrium phase of ferrite and austenite in weld metal areas is fulfilled in specimens A (34.8), M1 (38.9), M2 (36.4), M3 (38.4) and M5 (45.9). The highest average hardness value of vikers in weld metal area is found in M5 specimen which is 255 HV. While the lowest value in specimen C is 238 HV.The highest Vickers average hardness value in the heat affected zone (HAZ) is in specimen A which is 271 HV and the lowest hardness is in specimen C which is 245 HV. High tensile strength values are found in specimen M5 with value 800 MPA. While the value of low tensile strength in M4 specimens which is 652 MPA