• Title/Summary/Keyword: Small Vessels

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An Investigation of the Noise in Ship Engine-Room and Cabins for Hearing Protection (I) (청력보호를 위한 선박 기관실 및 선실소음의 조사(I))

  • Yu, Y.H.
    • Journal of Power System Engineering
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    • v.3 no.3
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    • pp.97-103
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    • 1999
  • As the noise of ship engine room is too loud, the engineer who works in a ship engine-room has the trouble of hearing. In this paper deals the investigation of the noise of ship engine room and cabins with the internationally allowable noise exposure level and noise exposure time. Recently, the problem of engine-room noise is more serious because of shipowner wants to make small number and larger size of cylinder. Therefore, engineers work in a ship engine-room for a long time have the trouble of hearing when they are exposed the high noise level. In this study, two kinds of vessels were used to investigate the noise of engine room, engine-control room, bridge, offices and cabins. As criteria of sound levels, A-weighted sound pressure level and octave band pressure level were used.

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Effect of Process Parameters on Bead Formation in Nd:YAG Laser Welding of Thin Steels (저탄소 박판 강재의 Nd:YAG 레이저 용접부 형성에 미치는 공정변수의 영향)

  • 김기철;허재협
    • Journal of Welding and Joining
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    • v.19 no.3
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    • pp.317-324
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    • 2001
  • This study deals with high power Nd:YAG laser welding of thin steels for small pressure vessels. Full penetration welding at the overlap joint was performed so as to assure sufficient weld strength. Results showed that mid-depth weld size reduced drastically with increasing the travel speed. Position of focus had little effect on the bead formation even though short focal system was used. However, the shape factor and the bead width had closely related with the position of focus. Based on the microstructural inspection, acceptable weld was obtained when the overlap clearance was controlled up to 20% of the base metal thickness. In the case that the joint contained more clearance than the critical value, both the tensile shear strength and the tear strength were reduced. Results also demonstrated that shielding gases were proved to play a key role as far as the bead formation characteristics was taken into consideration. Blowing dry air through 5mm in diameter nozzle produced narrower bead cross-section than that of argon or nitrogen shielding.

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IV-gamma Globulin Therapy for Severe Abdomlnal Pain Refractory to Steroid Therapy in $Henoch-Sch\"{o}nlein$ Purpura (정맥투여용 면역글로불린에 반응한 심한 복통을 가진 $Henoch-Sch\"{o}nlein$ 자반증 3례)

  • Kim Yong-Ok;Lee Chang-Yeun
    • Childhood Kidney Diseases
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    • v.1 no.2
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    • pp.176-178
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    • 1997
  • Henoch-Scholein purpura is a systemic vasculitis of small blood vessels. It is characterized by nonthrombocytopenic purpura, abdominal pain, arthralgia and renal involvement. In Henoch-Scholein purpura, severe abdominal pain may be relived by steroid, but occasionally unresponsive to steroid and conventional analgesics therapy. We tried IV-gamma globulin for severe abdominal pain, unresponsive to steroid, analgesics, and antispasmodics therapy in HSP, and experienced dramatic symptomatic improvement. So we report three cases of IVIG therapy against severe abdominal pain in HSP with a brief review of literatures

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Spontaneous hemangiosarcoma in a Bengal tiger(Panthera tigris) (벵갈 호랑이에서 자연발생한 혈관육종)

  • Kang, Boo-hyon;Kim, Dae-yong;Shin, Nam-sik;Kwon, Soo-wan
    • Korean Journal of Veterinary Research
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    • v.36 no.1
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    • pp.143-150
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    • 1996
  • Tumor masses from a Bengal tiger (Panthera tigris) of 13 years in age raised at the natural farm in Yong-In were examined grossly and microscopically. The tumors were observed in the subcutis, lung, heart, liver, pancreas, kidney, cecum and spleen. Histologically the tumors were composed of solid anaplastic cells that formed mature or immature small blood vessels and invaded the adjacent parenchyma. The nuclei of the tumor cells were large, vacuolated, and round or ovoid, sometimes dense and ovoid or spindle. The mitotic figures were common and the boundaries between the cells were indistinct. The stroma was very sparse. A diagnosis of this case was made as hemangiosarcoma on the basis of gross and microscopic features.

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A Study on the Flame Propagation Velocity of Methyl Alcohol (메틸알콜의 화염전파속도에 관한 연구)

  • Choi Jae-Wook
    • Fire Science and Engineering
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    • v.19 no.3 s.59
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    • pp.44-51
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    • 2005
  • The flame propagation velocity and the flame arrival time of methyl alcohol, which is widely used as a material of paint industry and organic synthesis, d mixing solvent, and an analytical reagent, were examined at different temperatures and concentrations. It was found that the smaller the vessel size, the easier and faster the combustion. The maximum combustion velocity was 200 cm/sec in the small vessel at $30^{\circ}C$. The flame arrival time was determined to be longer with larger vessels. and shorter with higher concentrations.

Characterization and Preparation of Electrospun Poly(ethylene terephthalate) (PET) Nonwoven/Polyurethane (PU) composites (전기방사된 PET 부직포/PU 복합체의 제조 및 특성)

  • Kim, Kwan-Woo;Lee, Keun-Hyung;Kim, Chul-Ki;Kim, Hak-Yong;Lee, Sung-Gu;Park, Soo-Jin
    • Proceedings of the Korean Fiber Society Conference
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    • 2003.10b
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    • pp.275-276
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    • 2003
  • Electrostatic spinning or electrospinning has been recently paid attention to prepare ultrafine fiber mats which are composed of diameters in a range of submicrons to nanoscale size[l]. Due to small diameters and porous structure, electrosun fibers have a high specific surface area and expected to use for broad applications, such as filters, membranes, wound dressing materials, artificial blood vessels. a nonwoven fabric, a reiforcement of nanocomposites[2,3], etc. (omitted)

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Effects of Pinelliae Rizoma (PR) on asthma induced intra-nasal instillation of ovalbumin in mice (반하가 난황으로유발된 생쥐의 알레르기성 천식에 미치는 영향)

  • Jeong, Dong-Hwan;Kim, Jong-Han;Park, Su-Yeon;Choi, Jeong-Hwa
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.21 no.1
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    • pp.38-54
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    • 2008
  • Objective : This study was designed to investigated effects of Pinelliae Rizoma (PR) on asthma Methods : Detecting antigen specific antibody isotypes, cytokines in serum and bronchoalveolar lavage fluid (BALF). In addition, the present author also investigated changes in weight of spleen and proliferation rates of splenocytes. Finally, histopathological observation of the lung tissue was also investigated. Results : Oral administration of PR lowered OVA specific IgE levels in serum, IgG1 levels in serum and BALF. PR also decreased production levels of IL-4 in BALF. In addition, total cells in BALF were decreased by oral administration of PR effectively. In histapathological observation, PR group showed downward tendency of inflammatory cell infiltration around small vessels. Conclusion : PR is useful to treat patients with asthma and the mechanisms are related in suppression of Th2 skewing reactions.

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A Study on the Cost State of the Stow Net Fisheries. (연안안강망어업의 원가실태에 관한 연구)

  • 박정호
    • The Journal of Fisheries Business Administration
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    • v.7 no.1
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    • pp.27-41
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    • 1976
  • The results analyzed of the actual state of the stow net fisheries based on the cost expended in 1975 areas follows; The total cost of this fisheries will be 1, 672, 238 won; the production cost, 1, 588, 060 won (95%) ; the material cost in proportion to total cost (100%)408, 480won (24.4%);the labour cost, 1, 006, 480 won (60.2%) ; the expenses, 173, 100won(10.4%)and the commission and the interest payment, 84, 178won(5%). As above the commission and the interest payment doesn't need to be paid much, but only production cost should be paid in case of small scale inshore fisheries. The cost per unit of caches (per Kg) becomes 12 won, the ratio cost of sales (83.4%), the ratio of profit, 16.%. According to the adove, in case of the powered vessel; it shows a tendency of spending too much expenses owing to excessive payment of oil. And in case of nonpowered vessels, it shows a tendency of spending less expenses but still get much gains, due to the fact that the commission and the interest payment are less, and none is paid for fuel procurement.

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A Study on Autoignition of Fish Meal with Change of Ambient Temperature (주위온도 변화에 따른 어분의 자연발화에 관한연구)

  • 목연수;최재욱
    • Journal of the Korean Society of Safety
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    • v.7 no.1
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    • pp.47-56
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    • 1992
  • Spontaneous ignition charactenstics for fish meal were observed by performing experiments at constant ambient temperature and varying the ambient temperature sinusoidally. As the results of the experiments at a constant ambient temperature, the critical spontaneous ignition temperature of the sample for large, intermediate and small vessels was 170.5$^{\circ}C$, 177.5$^{\circ}C$ and 188.5$^{\circ}C$, respectively. The critical spontaneous ignition temperature decreased as the sample vessel size increased. Apparent activation energy of used fish meal calculated from the Frank-Kamenetskii's thermal ignition theory was 37.60Kcal/mol. In case of varying the ambient temperature sinusoidally, the amplitudes of temperature were 1$0^{\circ}C$, 2$0^{\circ}C$ and 3$0^{\circ}C$ respectively with the period in each amplitude 1hr, 2hrs and 3hrs. The results showed that the critical spontaneous ignition temperatures at the varied amplitudes of temperature were lower than that at the constant anbient temperature and increased as the amplitude increased. At the same amplitude, the critical spontaneous ignition temperature increased with the period.

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Comparisons of Hydrodynamic Characteristics of Superyacht with Respect to the Variation of Hull Form (자유수면을 포함한 수퍼요트 주위의 점성유동 해석)

  • Kim, Tae-Yun;Hyun, Beom-Soo
    • Journal of the Society of Naval Architects of Korea
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    • v.45 no.3
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    • pp.337-343
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    • 2008
  • There are various hull types on the mid-size superyachts around $30\;{\sim}\;45m$. In any case, it is important to design the proper hull shape in viewpoint of the reduction of wave resistance, because small vessels such as superyachts are running at relatively higher Froude Number than other merchant ships. FLUENT with a VOF option was employed to investigate the flow fields around the superyachts having three-typical hull types: U-, V-types and catamaran. Overall performances including free surface flow were compared to figure out hydrodynamic characteristics of superyachy by numerical simulation.