7 research outputs found
State of the art in protection of erosion-corrosion on vertical axis tidal current turbine
No full textAn Analytical Approach to Modeling of Motion-Response of Floating Structure for Ocean Renewable Energy Conversion System
No full textOcean renewable energy research has been progressing well. Supporting structures are needed to convert energy from the sea. This paper discusses the response of the floating structure for ocean renewable energy conversion system by providing a simple design of floating structure. Due to its function, the system is limited for the pitching motion. By using the Lagrange formula, the equation of motion of the system can be obtained. In the analysis, there are three variations of wave period to determine the response of floating structure motion. The result shows the trend where the larger wave periods induce larger intersection angle (larger response) of the structure. The floating structure configuration for the ocean energy converter should be determined in such a way that have the most stable motion-response in any condition. The stability of floating structure will affect the current forces in the rotated turbine. It needs a specific design to hold the stability of floating structure.</jats:p
On Offshore Engineering Rules for Designing Floating Structure of Tidal Current Energy Conversion System
No full textOffshore engineering rules have been important part in supporting industrial development of tidal current energy conversion (TCEC) systems. The rules have been considered as guidelines for design of fixed type of TCEC systems, particularly those provided by European Marine Energy Centre (EMEC). However, for floating type of TCEC system, this is not the case. In fact, floating systems have a potential application for particular area of interests, for example in the area with strong currents at the seawater surface or in that with minimal infrastructure for installation support. In future, floating TCEC systems might be installed at the offshore area, even though the current application is commonly at the nearshore. Therefore, it may be beneficial to adopt relevant aspects of the offshore engineering rules for the floating structure design to support TCEC systems. This paper identifies elemental rules which may be suitable for application in the design of this type of floating structure. It includes choice of configurations, dynamic response analysis, material selection, mooring-water depth analyses and removal. This work is an important part of the whole big effort in supporting the development of ocean renewable energy industries.</jats:p
Uncertainty analysis of ocean outfalls
No full text Variability and uncertainty are inherent in an ocean outfall system and will cause variation in estimated initial dilution and bacterial concentration at areas of interest near the discharge. Uncertainty analysis is therefore useful in evaluating the likely performance of the outfall and in determining if it will comply with relevant government regulations. This paper identifies the uncertainty in outfall design parameters for an outfall involving a single, horizontal, round buoyant jet discharging into an unstratified seawater environment. A case study based on data from the Spaniard's Bay outfall in Newfoundland, and using a Monte Carlo simulation, is presented and compared with some, limited, site data that are available. It is shown that the analysis adequately describes the probabilistic nature of the initial dilution and bacterial concentration and that it would be useful for practical design purposes.Key words: bacterial pollution, buoyant jet, initial dilution, Monte Carlo simulations, probabilistic design, sewage discharge, ocean outfalls, uncertainty analysis, water quality standard. </jats:p
ANALISIS PEMIKIRAN SYEKH YASIN AL-FADANI TENTANG HISAB RUKYAT TRADISIONAL
No full textHisab rukyat is an absolute problem in the field of astronomy. In this research on reckoning rukyat, the author refers to Sheikh Yasin al-Fadani's thought of reckoning rukyat in Kitab al-Mukhtasor al-Muhadzab fi Ihtiroji al-Awqat wa al-Qiblah bi ar-Rubi' al-Mujib, with the research approach used is the syar'i astronomy and character approach, in this case Sheikh Yasin al-Fadani. From the results of the study, the authors found that Syekh Yasin al-Fadani's astronomical scientific Sanad was the highest sanad obtained from several of his teachers, both from those in the Middle East and from the Archipelago. That is, Sheikh Yasin al-Fadani is connected with his astronomical scientific chain with a number of scholars in the world and in the archipelago. Regarding the problem of Sheikh Yasin al-Fadani's rukyat reckoning thought which is still fairly classic, such as the use of Rubu 'Mujayab, it is not much different from the rukyat reckoning system in today's era. So it can be said that Sheikh Yasin al-Fadani's rukyat reckoning thinking is in line with what is in the astronomy literature today, both in the calculation system for the beginning of prayer times, Qibla direction, calendar and in determining the beginning of the month.
Keywords: Hisab Rukyat, Rubu’ Mujayab, Sheikh Yasin al-FadaniHisab rukyat sudah merupakan masalah yang mutlak ada dalam bidang keilmuan falak. Dalam penelitian mengenai hisab rukyat ini penulis merujuk kepada pemikiran hisab rukyat Syekh Yasin al-Fadani dalam Kitab al-Mukhtasor al-Muhadzab fi Ihtiroji al-Awqat wa al-Qiblah bi ar-Rubi’ al-Mujib, dengan pendekatan penelitian yang digunakan adalah pendekatan astronomis syar’i dan pendekatan tokoh, dalam hal ini Syekh Yasin al-Fadani. Dari hasil penelitian, penulis menemukan bahwa Sanad keilmuan falak Syekh Yasin al-Fadani merupakan sanad tertinggi yang didapatkan dari beberapa gurunya, baik dari yang di Timur Tengah maupun dari Nusantara. Artinya, Syekh Yasin al-Fadani ini terhubung sanad keilmuan falaknya dengan sejumlah ulama di dunia maupun di Nusantara. Mengenai masalah pemikiran hisab rukyat Syekh Yasin al-Fadani yang masih terbilang klasik ini, seperti penggunaan Rubu’ Mujayab tidak jauh berbeda dengan sistem hisab rukyat di zaman sekarang ini. Sehingga dapat dikatakan bahwa pemikiran hisab rukyat Syekh Yasin al-Fadani ini searah dengan apa yang ada dalam literature falak sekarang ini, baik dalam sistem hisab awal waktu shalat, arah kiblat, penanggalan maupun dalam penentuan awal bulan.
Kata Kunci: Hisab Rukyat, Rubu’ Mujayab, Syekh Yasin al-Fadani
