Prelimenary Modeling for Assessing Tidal Stream Energy Potential at the Alas Strait, Indonesia

This study is on ocean current prelimenary modelling in Alas Strait, Indonesia, to be compared with the field observation data. The model maps coordinate for ocean current so that the potential energy resource can be identified. The model simulation is established with two different scenarios; the first scenario is using windspeed factor and the second without using that factor. Complementary variables such as bathymetry, water elevation, bottom friction, and eddy viscosity have the same value for both scenarios. This ocean current modelling use finite element method with flexible mesh. This method use two dimension numerical solution from the average incompressible Reynolds Navier – Stokes equation with the assumption from Boussinesq dan hydrostatic pressure. This model consists of continuity equation and momentum which closed by turbulen scheme. This study concludes the first scenario is a success and valid with the water surface elevation mean error is 4.2% and water current speed mean error is 10.7%. The second scenario is unseccesful as indicated by the water surface elevation mean error of 13.4% and the water current speed mean error of 11,7%, and also the phase and the trend of current speed is verging the field observation data

Analisa Risiko Keselamatan dan Kesehatan Kerja (K3) terhadap Kecelakaan Kerja serta Lingkungan dengan Menggunakan Metode Hazard and Operability Study (HAZOP) pada Proses Scrapping Kapal

Kapal merupakan moda transpotasi untuk memindahkan penumpang atau barang dari satu tempat ke tempat lain melalui laut. Kapal dengan umur lebih dari 25 tahun secara umum tidak dapat dioperasikan lagi karena adanya Peraturan Menteri Perhubungan pada tahun 2005 . Ketika umur kapal bertambah, maka kapal tersebut menjadi tidak efisien untuk dioperasikan. Scrapping kapal pada saat ini dianggap sebagai solusi terbaik kapal yang tidak beroperasi. Kegiatan Scrapping kapal meliputi persiapan peralatan dan pekerja, bersandarnya kapal, pemotongan dan pengiriman material hasil scrapping. Tujuan utama dari penelitian ini adalah menyusun skenario risiko   dan menilai risiko yang ada pada industri scrapping kapal di Bangkalan Madura dengan metode Hazard and Operability Study (HAZOP). Metode HAZOP merupakan suatu cara identifikasi suatu risiko yang terjadi pada setiap pekerjaan dengan menggabungkan 2 kata penting yaitu parameter dan guideword menghasilkan penyimpangan (deviasi) hingga memberikan usulan tindakan pencegahan pada risiko kecelakaan. Analisis data dilakukan mulai mempersiapkan perlengkapan dan kondisi pekerja hingga pengiriman hasil scrapping. Metode berfungsi untuk mengetahui tingkat/level kecelakan pekerja dan dampak terhadap lingkungan di usaha  scrapping kapal. Risiko terekstrim diperoleh oleh pembersihan sisa bahan bakar/oli dengan menggunakan sabun dengan nilai 19,32. Tindakan pencegahan meliputi Memperhatikan     faktor-faktor     keselamatan     pada     waktu perencanaan, pembangunan sistem keamanan, sistem keselamatan bagi pekerja ataupun lingkungan, hingga pengawasan atau pengecekan setiap pekerjaan, menyelidiki kerusakan yang terjadi pada kecelakaan dan memelihara kalender kejadian

Horizontal Pendulum Performance Analysis with Multilevel Model Plate on Ocean Wave Electric Power Plant (PLTGL)

Abstract - With the times and the industry, the energy sources such as fossil fuels dwindling. It encourages all parties to be more advanced and developed by creating solutions to renewable energy generation with the latest innovations, one of which is the sea wave power plant - pendulum system. Ponton who uses pendulum system is one tool used to convert from ocean wave energy into electrical energy. In this study using the test conditions without using ballast onshore and off-shore testing with the ballasts. Obtained from testing the many rounds that can be generated pendulum pie plate thickness and the angle of the pontoon. To test the largest on-shore power obtained on the test using arc angle 30 °, 3 mm thick, the angle of 60o power produced 0036 watts. For testing offshore in the ballasts 12 cm, 15 cm, 17.5 cm, the largest power generated at 15 cm ballasts with 0041 watts power on pie, thick, and a tilt angle equal to the on-shore testing. Number of rounds with time, the on-shore testing that produces the greatest value in the segment with an angle of 30 °, a thickness of 3 mm the angle of 60o value obtained 0.938 rad / s. In the off-shore pengjuain is greatest in the ballasts 15 with 0847 rad / s.

Proses Biostimulasi dengan Optimasi Nutrien Untuk Bioremediasi Tanah Tercemar Tumpahan Minyak Mentah Dikawasan Pantai

The Bioremediation procec is aplication basic of priciples biologycal proces for treatmnet ground water, siols and sludges contaminated by chemical hazard waste. Bioremediation with added nutrien is biostimulation metode. Biostimulation added nutriens to growht of mikroba. The suscses of bioremediation proses measure from prosen removal contaminan consentration in soils atau ground waters. Result reseach optimum value of added nutrien with rasio N:P is 107,63 : 1, with (% P) is 8,471 and removal consentration of oil coefisien ( k ) 0,033 /day. The research use added nutrien 8,47 % P with rasio N : P = 105,5 : 1, prosen bioremediation is 88,47%. Output regretion analisis R-Sq(adj) = 82,2% .This result can response high significanti. The reserch do at land/soils near East Surabaya beach in Kelurahan Keputih Kecamatan Sukolilo from September-November, 2007

Experience in Oceanographic Surveys for Designing 100 kW Tidal Current Energy Conversion Systems

Nowadays tidal current energy conversion system (TCECS) is being developed with a capacity of 100 kW for Indonesian waters. The design process is based on the results of field measurements, i.e., ocean currents, tides, ocean waves, and bathymetry. This paper aims to explain the experiences when collecting oceanography data in a potential site for TCECS. The survey method is that the equipment placed on the seabed will emit signals that can record flow and wave data according to the desired time and depth. The survey process, especially for the tidal current energy application, requires good preparation so as not to fail. The results of this paper explain the challenges and highlight the steps. These are technical, environmental, and survey permits. The technical aspects are tool stability, buoyancy effects, visualization tools with an underwater camera system, seawater brightness, and sedimentation. Environmental aspects are big waves, strong currents, and weather. The survey permit aspects are destruction and conservation area. Therefore, before the survey, safety procedures or documents must be made in the form of HIRA (Hazard Identification and Risk Analysis). The experiences of this survey are a novelty consideration for other surveyors in the tidal current energy aspect

Numerical simulation of foil with leading-edge tubercle for vertical-axis tidal-current turbine

The main disadvantage of the vertical-axis turbine is its low coefficient of performance. The purpose of this work was to propose a method to improve this performance by investigating the hydrodynamic forces and the flow-field of a foil that was modified with a sinusoidal leading-edge tubercle. NACA 63(4)021 was chosen as the original foil since it has a symmetrical profile that is suitable for use on a vertical-axis tidal-current turbine. The study was conducted using a numerical simulation method with ANSYS-CFX Computational Fluid Dynamics (CFD) code to solve the incompressible Reynolds-Averaged Navier-Stokes (RANS) equations. Firstly, the simulation results of the original foil were validated with available experimental data. Secondly, the modified foils, with three configurations of tubercles, were modelled. From the simulation results, the tubercle foils, when compared with the original foil, had similar lift performances at low Angles of Attack (0-8 degrees of AoA), lower lift performances at medium AoA (8-19 degrees) and higher lift performances at high AoA (19-32 degrees). A tubercle foil with Height/Chord (H/C) of 0.05 can maintain the static stall condition until 32 degrees. Therefore, a vertical-axis turbine with tubercle-blades provides an opportunity to increase its performance by extending the operational range for extracting energy in the dynamic stall condition

Quranic Multiple Intelligences and its Implementation in Educational Institutions

This article is qualitative-descriptive analytical research on multiple intelligences, a theory which Howard Gardner introduced. According to Howard Gardner's findings, the concept of multiple intelligences has been widely known and used in educational institutions. Multiple intelligences are also considered a theory that first recognized the diversity of human intelligence. With multiple intelligences, it can be said that no child is stupid. Therefore, each child is born with intelligence that is not always equal to each other. In Islam, the Quran is a complete guide for life. This research has discovered the powerful instruments to develop Qur'anic multiple intelligences in educational institutions through literature. With the thematic interpretation method (maudhui) approach, this study described the practical efforts, using the mindset of interpretation and reflection, to develop the concept of multiple intelligences based on the perspective of the Quran. After researching, collecting, and analyzing all terms in the Quran that relate to intelligence, it is found that the Quran is distinguishing the concept of multiple intelligences. It can be used further as a practical guide for educational institutions in developing the concept of multiple intelligences from the perspective of the Qura