• Title/Summary/Keyword: Fuel Oil Price

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Parametric study of propeller boss cap fins for container ships

  • Lim, Sang-Seop;Kim, Tae-Won;Lee, Dong-Myung;Kang, Chung-Gil;Kim, Soo-Young
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.6 no.2
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    • pp.187-205
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    • 2014
  • The global price of oil, which is both finite and limited in quantity, has been rising steadily because of the increasing requirements for energy in both developing and developed countries. Furthermore, regulations have been strengthened across all industries to address global warming. Many studies of hull resistance, propulsion and operation of ships have been performed to reduce fuel consumption and emissions. This study examined the design parameters of the propeller boss cap fin (PBCF) and hub cap for 6,000TEU container ships to improve the propulsion efficiency. The design parameters of PBCF have been selected based on the geometrical shape. Computational fluid dynamics (CFD) analysis with a propeller open water (POW) test was performed to check the validity of CFD analysis. The design of experiment (DOE) case was selected as a full factorial design, and the experiment was analyzed by POW and CFD analysis. Analysis of variance (ANOVA) was performed to determine the correlation among design parameters. Four design alternatives of PBCF were selected from the DOE. The shape of a propeller hub cap was selected as a divergent shape, and the divergent angle was determined by the DOE. Four design alternatives of PBCF were attached to the divergent hub cap, and the POW was estimated by CFD. As a result, the divergent hub cap with PBCF has a negative effect on the POW, which is induced by an increase in torque coefficient. A POW test and cavitation test were performed with a divergent hub cap with PBCF to verify the CFD result. The POW test result showed that the open water efficiency was increased approximately 2% with a divergent hub cap compared to a normal cap. The POW test result was similar to the CFD result, and the divergent hub cap with the PBCF models showed lower open water efficiency. This was attributed to an increase in the torque coefficient just like the CFD results. A cavitation test was performed using the 2 models selected. The test result showed that the hub vortex is increased downstream of the propeller.

Effects of Minimizing the Heating Space on Energy Saving and Hot Pepper(Capsicum annuum L.) Growth in the Plastic Greenhouse (온실 난방공간 최소화가 에너지 절감 및 고추 생육에 미치는 영향)

  • Tae Young Kim;Young Hoe Woo;Ill Hwan Cho;Young Sam Kwon;Si Young Lee;Han Ik Jang
    • Journal of Bio-Environment Control
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    • v.10 no.4
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    • pp.213-218
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    • 2001
  • In 2000, domestic protected cultivation area was about 52,189 ha including 13,621 ha of heating greenhouses. Recently, heating cost accounts for 25 to 30% of total production cost which has been increased due to the rise of oil price, while the heating cost was about 15% in other advanced countries. To reduce the heating energy cost, the study of minimizing the heating space of greenhouse have been conducted from 1998 to 1999. The system was developed to control the heating space according to crop growth by moving horizontal curtain up and down. Installation of the heating space-control curtain in greenhouse decreased heating capacity to 264 m$^3$compared to 661.5 m$^3$in the traditional curtain, and consumpted fuel was saved about 56% point in semiforcing culture and 28% point in retarding culture of pepper. In addition, uniform distribution of air temperature and relative humidity in greenhouse environment resulted in earlier flowering and higher yields in hot pepper.

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Unfair Restrain on Competition in Air Cargo Fuel Surcharge Case (공정거래법상 부당한 경쟁제한의 의미 - 항공화물 유류할증료 담합사건을 중심으로 -)

  • Lee, Chang Jae
    • The Korean Journal of Air & Space Law and Policy
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    • v.30 no.1
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    • pp.117-149
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    • 2015
  • On May 16, 2014 the Supreme Court of Korea rendered its decision with respect to litigation filed by All Nippon Airways Co., Ltd. ("ANA") for revocation of an order of correction and payment of a penalty imposed by the Korea Fair Trade Commission ("KFTC"). On or around September 2002, ANA and various airlines operating air cargo service from Japan to Korea were allegedly to have agree to introduce of fuel surcharge into their rates on cargo fares in an attempt to recoup falling profits from rising of oil price. As this hard core cartel was per se prohibited under Korean competition law (The Monopoly Regulation And Fair Trade Act), KFTC began an investigation and consequently with fruitful results imposed an amount of penalty and issued an order of prohibition. ANA protested against this imposition by filing suit against KFTC under the reasons that (1) their agreement was simply pursuant to the relevant laws and regulations including Air Transport Agreement between Korea and Japan, (2) there was an administrative guidance from Japanese government to allow this agreement, (3) extraterritorial application of Korean competition law to the agreement in this matter was improper as it was made within Japan and targeted only for the shipment from Japan to Korea: accordingly there is not a direct and serious effect between the agreement and any result of anti-competitive. This article aims to review ANA's allegation and the judgement delivered by Korean court under some issues respectively; (1) whether there is an effectively actual anti-competitive cartel between airlines including plaintiff, (2) whether filed rate doctrine is reasonable and applicable in this case for precluding wrongfulness, (3) what is the reasonable limitation of boundaries in extraterritorial application of Korean competition law. Additionally, this article also suggests to concern particular features of air transport business as an regulated industry in judging the unfair restrain on competition.

Larch Pellets Fabricated with Coffee Waste and the Commercializing Potential of the Pellets (커피박과 낙엽송 목분을 이용한 펠릿 제조 및 이에 대한 상용화 검토)

  • Yang, In;Han, Gyu Seong;Oh, Seung Won
    • Journal of the Korean Wood Science and Technology
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    • v.46 no.1
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    • pp.48-59
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    • 2018
  • This study was conducted to suggest the effective management and recycling processes of coffee waste, which can be easily obtained from coffee shops and coffee-related products industries. Prior to the fabrication of pellets, the potential of coffee waste as a raw material of pellet was investigated through the examination of its chemical compositions and fuel characteristics. Major gradient included in coffee waste was holocellulose, followed by fat/oil and protein. Coffee waste contained a small quantity of ash (0.7%), such as calcium, sodium, potassium and magnesium. Interestingly, coffee waste was easily dried probably due to its porous structure. Pellets fabricated with coffee waste and larch sawdust showed good fuel characteristics, such as moisture content, ash content, density and durability. The pellets exceed greatly the minimum requirements of $1^{st}$-grade wood pellet standard designated by National Institute of Forest Science (NIFOS). Particularly, the high calorific value of coffee waste showed the potential as a raw material of pellet. However, owing to high nitrogen and sulfur contents, coffee waste is like to be used as a raw material of wood pellet for combined heat and power plants equipped with a reduction system of $NO_x$ and $SO_x$ gases. On the other hand, 91 wt% larch sawdust and 9 wt% coffee waste are required to fabricate the $1^{st}$-grade wood pellets designated by NIFOS. Pellets fabricated with the conditions are estimated to have nitrogen content of 0.298% and sulfur content of 0.03%. Lastly, if amounts of coffee waste and sawdust in the production of wood pellets are adequately adjusted according to its purchasing price, the manufacturing cost of pellet can effectively be reduced. In addition, it is expected tp prepare the effective recycling process of waste and to relieve the environmental burden with the reduction of waste from the commercialization of coffee waste/larch pellets.

Cellulosic Ethanol Production (셀룰로식 (Cellulosic) 에탄올 생산)

  • Chung, Chang-Ho
    • KSBB Journal
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    • v.23 no.1
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    • pp.1-7
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    • 2008
  • The world demand of ethanol as an alternative fuel for gasoline is increasing rapidly because of high oil price and global climate change. Most of ethanol is currently produced from corn grain or sugars in sugarcane and sugar beet. Because these sources compete with foods and animal feed and are not expected to be enough for future demand of ethanol. Thus, cellulosic ethanol from agricultural residues or wood has to be commercialized in near future. Typical cellulosic ethanol production consists of pretreatment, enzyme hydrolysis, fermentation and product separation. This paper reviews the principles and status of each step and discusses issues for cellulosic ethanol production.

Dynamical Study on the Blasting with One-Free-Face to Utilize AN-FO Explosives (초유폭약류(硝油爆藥類)를 활용(活用)한 단일자유면발파(單一自由面發破)의 역학적(力學的) 연구(硏究))

  • Huh, Ginn
    • Economic and Environmental Geology
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    • v.5 no.4
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    • pp.187-209
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    • 1972
  • Drilling position is one of the most important factors affecting on the blasting effects. There has been many reports on several blasting factors of burn-cut by Messrs. Brown and Cook, but in this study the author tried to compare drilling positions of burn-cut to pyramid-cut, and also to correlate burn-cut effects of drilling patterns, not being dealt by Prof. Ito in his theory, which emphasized on dynamical stress analysis between explosion and free face. According to former theories, there break out additional tensile stress reflected at the free face supplemented to primary compressive stress on the blasting with one-free-face. But with these experimented new drilling patterns of burn-cut, more free faces and nearer distance of each drilling holes make blasting effects greater than any other methods. To promote the above explosive effect rationary, it has to be considered two important categories under-mentioned. First, unloaded hole in the key holes should be drilled in wider diameter possibly so that it breaks out greater stress relief. Second, key holes possibly should have closer distances each other to result clean blasting. These two important factors derived from experiments with, theories of that the larger the dia of the unloaded hole, it can be allowed wider secondary free faces and closes distances of each holes make more developed stress relief, between loaded and unloaded holes. It was suggested that most ideal distance between holes is about 4 clearance in U. S. A., but the author, according to the experiments, it results that the less distance allow, the more effective blasting with increased broken rock volume and longer drifted length can be accomplished. Developed large hole burn-cut method aimed to increase drifting length technically under the above considerations, and progressive success resulted to achieve maximum 7 blasting cycles per day with 3.1m drifting length per cycle. This achievement originated high-speed-drifting works, and it was also proven that application of Metallic AN-FO on large hole burn-cut method overcomes resistance of one-free-face. AN-FO which was favored with low price and safety handling is the mixture of the fertilizer or industrial Ammonium-Nitrate and fuel oil, and it is also experienced that it shows insensible property before the initiation, but once it is initiated by the booster, it has equal explosive power of Ammonium Nitrate Explosives (ANE). There was many reports about AN-FO. On AN-FO mixing ratio, according to these experiments, prowdered AN-FO, 93.5 : 6.5 and prilled AN-FO 94 : 6, are the best ratios. Detonation, shock, and friction sensities are all more insensitive than any other explosives. Residual gas is not toxic, too. On initation and propagation of the detonation test, prilled AN-FO is more effective than powered AN-FO. AN-FO has the best explosion power at 7 days elapsed after it has mixed. While AN-FO was used at open pit in past years prior to other conditions, the author developed new improved explosives, Metallic AN-FO and Underwater explosive, based on the experiments of these fundmental characteristics by study on its usage utilizing AN-FO. Metallic AN-FO is the mixture of AN-FO and Al, Fe-Si powder, and Underwater explosive is made from usual explosive and AN-FO. The explanations about them are described in the other paper. In this study, it is confirmed that the blasting effects of utilizing AN-FO explosives are very good.

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