• 한국수산과학회지
• /
• 제22권3호
• /
• pp.129-137
• /
• 1989

1986년 12월 1일 강원도 명주군 옥계면 김진삼 이앞 연안에서 삼중책망으로 채포한 성숙한 도루묵을 이용하여 현장(선상)에서 인공수정시켜, 실내 사육실로 운반한 후 난발생과정과 부화자치어의 형태를 연구하였다. 난은 구형이고 침성점착난이며 난경은 $3.1\~3.4$mm(평균 3.3 mm, n=10)이었고, 많은 소유구를 가진다. 자연산난된 알은 지름이 약 4 cm인 알덩이를 형성하였다. 수온 $8.7\~12.3^{\circ}C$ 범위에서 수정 후 65일만에 부화되었다(적산수온 $663\~902^{\circ}C$). 부화직후 자어는 전장 $8.5\~10.2$ mm 범위이며, 근절수는 11+40(?)이었고, 가슴지느러미 줄기 5개가 발달하여 있었다. 부화 후 24일 째 전장 19.4 mm 자어는 난황을 완전히 흡수하였고, 배지느러미의 원기가 나타났다. 부화 후 32일째 전장 23.4 mm는 각 지느러미 줄기가 완성되고 치어기에 달한다. 부화 후 56일째 전장 29.9 mm의 치어는 체형이 거의 성어와 닮으며 체측에 4개의 흑색소포덩이가 나타났다. 전새개골 극은 전장 15.6 mm일때 4개가 나타났고 전장 24.4 mm에서 5개가 생겼다. 가슴지느러미는 전장 15 mm 전후에 둥근형에서 성어의 형태로 바뀌었다. 도루묵의 자어는 항문의 위치가 몸중앙보다 앞쪽에 위치한 점과 꼬리의 배쪽 가장자리를 따라 흑색소포가 발달한 점이 배도라치류의 자어와 닮았으나, 전새개골에 극을 가지고 있어 극이 없는 배도라치류의 자어와 구별되었다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1995년도 하계학술대회 논문집 C
• /
• pp.1394-1397
• /
• 1995

In the hazardous areas where explosive gases, vapor or mists exist, electrical apparatus and installations must be of explosion-proof construction to prevent or limit the danger of the ignition of potentially explosive atmosphere. In Korea, nine types of protection have been specified in the government regulations at present: flameproof enclosure, pressurization, oil immersion, increased safety, intrinsic safety, non-incendive, sand filling, encapsulation, and special types. Among these types, the intrinsic safety has the construction which limit or by-pass igniting the electric energy using electronic devices. This type has lots of merits but at the same time requires a high-degree of technology. In this paper, we investigated several dominating factors which affect the minimum ignition energy: this energy plays a very important role in design and evaluation of the intrinsic safety type electrical apparatus. Eletrode material, which is one of the most important factors, was intensively studied for the five sorts of material(Al, Cd, Mg, Sn, and Zn) with performing experiment in a low-voltage inductive circuit using IEC-type spark apparatus. The experimental results show that the minimum ignition energy of electrode material is varied: highest in Cd and lowest in Sn. We also confirmed the effect of eletrode make-and-break speed and magnetic field magnitude.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
• /
• pp.116.1-116.1
• /
• 2010

저급 연료원인 오일샌드는 아스팔트와 같은 중질유를 10% 이상 함유한 모래 또는 사암으로서, 겉으로는 시커먼 흙이나 모래처럼 보이나 내부에는 bitumen, 모래(점토) 및 물 등이 광물질 70~80%, bitumen 10~18%, 물 3~5% 정도의 비율로 혼합되어 있는데, 가열 또는 용매 추출 방식으로 오일샌드에 포함되어 있는 bitumen을 분리하여 정제하면 원유를 생산할 수 있으므로 고유가 시대의 대체에너지원으로 세계적인 석유회사들이 개발을 진행하고 있다. 따라서, 본 연구에서는 이러한 저급 연료원인 오일샌드 bitumen의 활용기술 개발을 위하여 기초특성 분석 결과 bitumen과 가장 유사한 특성을 가지는 것으로 파악된 중질잔사유를 대상으로 가스화를 통한 액체연료 전환을 위해 고점도 시료공급장치, 가스화기, 집진장치, 탈황장치, 수성가스 전환장치, 합성가스 압축장치, DME 전환장치 등으로 구성되는 시스템을 구축한 후 시험을 진행하였다.

• 환경위생공학
• /
• 제8권2호
• /
• pp.123-148
• /
• 1993

Over the past-decade of reform and opening up to the outside world, China#s GNP doubled which now ranks eighth in the world, making an average 9.6% increase annually. Some industrial products such as steel, crude oil and power generation rank fourth in the world, while output of coal and cement rank first. In the agricultural sector, China ranks first in the output of grain, cotton, meat and basically solved the problem of providing food and daily necessities for 22% of the world#s population, The Chinese government has set the objectives in environmental protection plan to be achieved by the year 2000 together with ecological protection. During the Seventh Pive-Year Plan(1985-90), Chains#s annual investment in controlling environment pollution was about 10 billion Yuan, or 0.7% of her GNP, while during the Eighth Five-Year Plan, effort will be made to increase such investments, in terms of the GNP, possibly to 0.85"1% . However, the expanding development including industrial production will increase large amounts of pollutants into the environment and efforts are underway to deal with these pollution. *대한위생학회장 Regional community are faced with serious environmental problems. For instance, so called# Yellow Sand Storm# from China is one of the case. Recently, to make matter worse, acid rain and dry depositation from transboundary air pollution is tend to increase mainly because of emissions from mainland China. Therefore, the countries concerned in the region, should seek to promote international cooperation on environmental issues. An overall aspects of development and environmental programs in China are presented.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2004년도 춘계학술발표회
• /
• pp.11-19
• /
• 2004

When pile foundation constructed by driving method, it is desirable to perform monitoring and estimation of pile drivability and bearing capacity using some suitable tools. Dynamic Pile Monitoring yields information regarding the hammer, driving system, and pile and soil behaviour that can be used to confirm the assumptions of wave equation analysis. Dynamic Pile Monitoring is performed with the Pile Driving Analyser. The Pile Driving Analyser (PDA) uses wave propagation theory to compute numerous variables that fully describe the condition of the hammer-pile-soil system in real time, following each hammer impact. This approach allows immediate field verification of hammer performance, driving efficiency, and an estimate of pile capacity. The PDA has been used widely as a most effective control method of pile installations. A set of PDA test was performed at the site of Donghea-1 Gas Platform Jacket which is located east of Ulsan. The drilling core sediments of location of jacket subsoil are composed of mud and sand, silt. In this case study, the results of PDA test which was applied to measurement and estimation of large diameter open ended steel pipe pile driven by underwater hydraulic hammer, MHU-800S, at the marine sediments were summarized.

• 한국식생활문화학회지
• /
• 제35권1호
• /
• pp.28-54
• /
• 2020

This study aims to investigate the food preservation methods adopted by the Joseon Dynasty, which existed before the 17^th century. A total of 232 food preservation methods were discovered in 25 books, and could be classified by their targeted food types: vegetables (84), sea foods (60), meats (41), fruits (37), and others (10). Depending on the preservation method applied, they are classified as food drying, soaking, mud cellar preservation, and other preservation. Food drying is further classified into 8 sub-types: drying, sun-drying, shadow-drying, wind-drying, dry heat, combined drying, smoking, and others. Soaking could be sub-divided into using salt, ash, dry sand, bran, fermented paste, wet distillers grains, oil, and others. Mud cellar preservation is sub-classified into installing shelf inside the mud cellar, making the mud cellar for food preservation, and making hole or underground tunnel for food preservation. Other food preservation methods include minimizing moisture loss by applying beeswax on a section of the vegetable stem, and cutting the vegetables or fruits with their branches and leaves for food preservation.

• Plant Biotechnology Reports
• /
• 제5권3호
• /
• pp.235-243
• /
• 2011

The non-edible plant Jatropha curcas L. is one of the most promising feedstock for sustainable biodiesel production as it is not a source of edible vegetable oils, produces high amounts of oil (approx. 30-60% in dry seeds) and does not require high-cost maintenance. However, as with other undomesticated crops, the cultivation of J. curcas presents several drawbacks, such as low productivity and susceptibility to pests. Hence, varietal improvement by genetic engineering is essential if J. curcas is to become a viable alternative source of biodiesel. There is to date no well-established and efficient transformation system for J. curcas. In this study, we tested various physical wounding treatments, such as sonication and sand-vortexing, with the aim of developing an efficient Agrobacterium-mediated transformation for J. curcas. The highest stable transformation rate (53%) was achieved when explants were subjected to 1 min of sonication followed by 9 min of shaking in Agrobacterium suspension. The transformation frequency achieved using this protocol is the highest yet reported for J. curcas.

• International Journal of Automotive Technology
• /
• 제3권2호
• /
• pp.47-52
• /
• 2002

The integration of CAD/CAM/CAE in product development is the key to realize concurrent engineering. Generally, different systems are employed in product development departments. These different systems create a lot of trout)toes such as difficulty in communication, misunderstanding and so on. A new approach to integrate CAD/CAM/CAE in one system based on CATIA thor the end-to-end process in cylinder head development is presented. Hulti Model Technology (MMT) is used to create consistent and associated CAD models for the end-to-end process in cylinder head development. The concept and method to create and organize multi models are discussed. A typical four-layer structure of HHT for mechanical products is defined. The multi level structure of the cylinder head models based on MMT is provided. The CAD models of cylinder head created based on MMT can be used as the consistent model. All models in the downstream of cylinder head development such as structure analysis, CFD, sand core design , casting simulation and so oil are associated with the CAD models. Practice shows the approach in this paper enables the development process to be carried concurrently and can obviously shorten time to the market, reduce product cost and improve product quality.

• 대한설비공학회:학술대회논문집
• /
• 대한설비공학회 2008년도 하계학술발표대회 논문집
• /
• pp.1315-1320
• /
• 2008

An experimental study was carried out to study the solid-liquid mixture upward flow in a vertical and inclined annulus with rotating inner cylinder. Lift forces acting on a fluidized particle plays a central role in many importance applications, such as the removal of drill cuttings in horizontal drill holes, sand transport in fractured reservoirs, sediment transport and cleaning of particles from surfaces, etc. Field measurements have revealed that the pressure drop over a borehole during drilling of a slim oil well or a well with a long reach can depend significantly on the rotation speed of the drill pipe. An accurate prediction of the annular frictional pressure drop is therefore important for conditions where the annular clearance is small. Effect of annulus inclination and drill pipe rotation on the carrying capacity of drilling fluid, particle rising velocity, and pressure drop in the slim hole annulus have been measured for fully developed flows of water and of aqueous solutions.

• 한국약용작물학회지
• /
• 제17권6호
• /
• pp.415-420
• /
• 2009

This study was carried out to select economical byproduct composts as the substitute for the traditional organic fertilizer, Yacto, in the cultivation of ginseng seedlings, and to investigate the application method of a selected compost. Among tested byproduct composts, popped rice hull compost was the best substitute for Yacto, while the application of domestic animal manure composts resulted in red skinned roots of ginseng seedlings. Optimal mixing ratio of the popped rice hull compost with virgin soil (fine sand) were 3~4 : 1 in bulk, showing the same root yield compared to that of conventional seedbed soil. When the popped rice hull compost was lower than $1\;{\pm}\;0.1%$ in nitrogen content, the expeller cake of oil seed was added to seedbed soil to rise nitrogen content until $1\;{\pm}\;0.1%$.