• 한국어류학회지
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• 제10권2호
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• pp.231-240
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• 1998

납자루아과(亞科)에 속하는 가시납지리(Acanthorhodeus gracilis)의 두골(頭骨), 척주(脊柱), 지느러미 골격을 조사하였다. 두개부(頭蓋部)에 천문이 없으며, 상사골(上篩骨)의 전단에 돌기가 없고, 안와설골(眼窩楔骨)은 2개로 되어 있다. 기저후두골(基底後頭骨) 돌기(突起)는 전반부에서부터 발달하였고, 상후두골(上後頭骨)은 높은 삼각형 형태의 돌기를 갖고 있으며, 미설골(尾舌骨)은 선단(先端)이 2분기(分技)되고 수평판(水平板)과 수직판(垂直板)의 후방(後方)이 넓어지며 후연(後緣)이 돌출되어 있다. 인두치(咽頭齒)는 1열로 인두치식(咽頭齒式)은 5 - 5이며 4개의 유리치(遊離齒)를 갖고 있다. 편대(扁帶)에는 오훼골(烏喙骨) 구멍이 없으며, 미골추체(尾骨推體)에는 미신경골(尾神經骨)이 나타나지 않고, 길고 가느다란 후요대돌기(後腰帶突起)를 갖는다. 유리신경간련(遊離神經間練)은 넓은 판상(板狀)이고, 신경간극(神經間棘)은 14~15개이며 제1~제4신경간극(神經間棘)은 하나의 기기골을 나머지는 두 개의 기기골을 기부(基部)에 갖고 있고, 혈관간극(血管間棘)은 11~12개이며 제1~제 4혈관간극(血管間棘)은 하나의 기기골을 나머지는 두 개의 기기골을 갖고있다.

• 태양에너지
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• 제15권2호
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• pp.3-11
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• 1995

본 논문은 히이트 파이프를 이용한 태양열 온수 급탕 시스템의 제작 및 그 열성능에 관한 내용이다. 국내 기후에 적합한 모델을 도출하기 위하여 본 연구에서는 여러번에 기초실증 실험을 수행하였다. 히이트 파이프는 구리로 제작하였으며 증발부, 단열부 및 응축부의 길이는 각각 1700mm, 100mm, 그리고 200mm이다. 증발부는, 특히 효율적인 집열을 위하여 얇은 구리로 만든 핀(fin)을 부착하였다. 연구결과를 살펴보면 작동 유체의 종류, 윅(wick)의 유무, 표면 처리 정도 그리고 그 밖의 여러 설계인자에 따라 히이트 파이프를 이용한 태양열 온수 급탕 시스템의 열성능이 적지 않은 영향을 받을 수 있음을 나타내고 있다.

• Corrosion Science and Technology
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• 제21권2호
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• pp.130-137
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• 2022

In this work, the degradation of high-pressure superheater tubes exposed to the flame of a duct burner in a heat recovery steam generator of a district heating system was evaluated. To assess the deterioration of the used superheater tube, the microstructure, microhardness, and tensile properties were investigated by comparison to an unused tube. The study found that a fin bound at the outer surface of the used tube became fragile only in the location facing the flame. This indicates that the tube was directly exposed to the flame from the duct burner or underwent abnormal overheating. While the unused tube showed a uniform value in hardness and equiaxial grain structure, the used tube revealed a decrease in hardness up to 105 HV and an increase in grain size with a plate-like morphology in the location facing the flame. The coarsening of the grain structure by the flame weakened the mechanical properties of yield strength, tensile strength, and elongation.

• 설비공학논문집
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• 제24권6호
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• pp.521-537
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• 2012

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2011. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) Research trends of thermal and fluid engineering have been surveyed as groups of fluid machinery and fluid flow, thermodynamic cycle, and new and renewable energy. Various topics were presented in the field of fluid machinery and fluid flow. Research issues mainly focused on the rankine cycle in the field of thermodynamic cycle. In the new and renewable energy area, researches were presented on geothermal energy, fuel cell, biogas, reformer, solar water heating system, and metane hydration. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer, nanofluids and industrial heat exchangers. Researches on heat transfer characteristics included heat transfer above liquid helium surface in a cryostat, methane hydrate formation, heat and mass transfer in a liquid desiccant dehumidifier, thermoelectric air-cooling system, heat transfer in multiple slot impinging jet, and heat transfer enhancement by protrusion-in-dimples. In the area of pool boiling and condensing heat transfer, researches on pool boiling of water in low-fin and turbo-B surfaces, pool boiling of R245a, convective boiling two-phase flow in trapezoidal microchannels, condensing of FC-72 on pin-finned surfaces, and natural circulation vertical evaporator were actively performed. In the area of nanofluids, thermal characteristics of heat pipes using water-based MWCNT nanofluids and the thermal conductivity and viscosity were measured. In the area of industrial heat exchangers, researches on fin-tube heat exchangers for waste gas heat recovery and Chevron type plate heat exchanger were implemented. (3) Refrigeration systems with alternative refrigerants such as $CO_2$, hydrocarbons, and mixed refrigerants were studied. Heating performance improvement of heat pump systems were tried applying supplementary components such as a refrigerant heater or a solar collector. The effects of frost growth were studied on the operation characteristic of refrigeration systems and the energy performance of various defrost methods were evaluated. The current situation of the domestic cold storage facilities was analyzed and the future demand was predicted. (4) In building mechanical system fields, a variety of studies were conducted to achieve effective consumption of heat and maximize efficiency of heat in buildings. Various researches were performed to maximize performance of mechanical devices and optimize the operation of HVAC systems. (5) In the fields of architectural environment and energy, diverse purposes of studies were conducted such as indoor environment, building energy, and renewable energy. In particular, renewable energy and building energy-related researches have mainly been studied as reflecting the global interests. In addition, various researches have been performed for reducing cooling load in a building using spot exhaust air, natural ventilation and energy efficiency systems.

• 한국어병학회지
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• 제6권1호
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• pp.1-10
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• 1993

발병한 양식 메기로 부터 vibrio속 균주를 분리하였다. 분리된 균주는 생물학적 생화학적 특성에 기초하여 동정한 결과 V. ordalii로 동정 되었다. 분리균은 glucose, lactose, maltose 와 salicine으로 부터 산을 생산 하였으며, arabinose, galactose, inocitol과 xylose는 이용하지 못하였다. 분리된 V. ordalii를 각각 KL-1, KL-2라 명명하였다. KL-l과 KL-2는 생리학적 특성이 유사하였다. 즉, pH 5-10, NaCl 0%~6.0%에서 발육하였으며, 또한 NaCl 7.0%, pH 10이상 그리고 pH5이하에서는 발육하지 않았다. KL-1 균주를 건강한 메기에 인공 감염시킨 결과 양식장에서 발병된 증상과 동일한 출혈성 궤양이 유발되었다. 감염 24시간 후에 나타난 흙은 반점은 접종 부위 주변에서 부터 확장되기 시작했으며, 감염 120시간 후부터는 배지느러미 부위까지 궤양이 확장되었다. 각각 온도에 따른 실험에서는 $25^{\circ}C$에서 폐사율이 70%로 나타났다. 약제 감수성 시험에서 KL-1 과 KL-2 균주는 모두 GM, K, N, S와 SxT에 감수성을 나타내었으나, CF 및 $L_2$와 VA에는 저항성을 나타내었다.

• 설비공학논문집
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• 제21권12호
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• pp.715-732
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• 2009

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2008. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) Research trends in thermal and fluid engineering have been surveyed in the categories of general fluid flow, fluid machinery and piping, new and renewable energy, and fire. Well-developed CFD technologies were widely applied in developing facilities and their systems. New research topics include fire, fuel cell, and solar energy. Research was mainly focused on flow distribution and optimization in the fields of fluid machinery and piping. Topics related to the development of fans and compressors had been popular, but were no longer investigated widely. Research papers on micro heat exchangers using nanofluids and micro pumps were also not presented during this period. There were some studies on thermal reliability and performance in the fields of new and renewable energy. Numerical simulations of smoke ventilation and the spread of fire were the main topics in the field of fire. (2) Research works on heat transfer presented in 2008 have been reviewed in the categories of heat transfer characteristics, industrial heat exchangers, and ground heat exchangers. Research on heat transfer characteristics included thermal transport in cryogenic vessels, dish solar collectors, radiative thermal reflectors, variable conductance heat pipes, and flow condensation and evaporation of refrigerants. In the area of industrial heat exchangers, examined are research on micro-channel plate heat exchangers, liquid cooled cold plates, fin-tube heat exchangers, and frost behavior of heat exchanger fins. Measurements on ground thermal conductivity and on the thermal diffusion characteristics of ground heat exchangers were reported. (3) In the field of refrigeration, many studies were presented on simultaneous heating and cooling heat pump systems. Switching between various operation modes and optimizing the refrigerant charge were considered in this research. Studies of heat pump systems using unutilized energy sources such as sewage water and river water were reported. Evaporative cooling was studied both theoretically and experimentally as a potential alternative to the conventional methods. (4) Research papers on building facilities have been reviewed and divided into studies on heat and cold sources, air conditioning and air cleaning, ventilation, automatic control of heat sources with piping systems, and sound reduction in hydraulic turbine dynamo rooms. In particular, considered were efficient and effective uses of energy resulting in reduced environmental pollution and operating costs. (5) In the field of building environments, many studies focused on health and comfort. Ventilation. system performance was considered to be important in improving indoor air conditions. Due to high oil prices, various tests were planned to examine building energy consumption and to cut life cycle costs.

• 설비공학논문집
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• 제20권12호
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• pp.844-861
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• 2008

The papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during the year of 2007 have been reviewed. Focus has been put on current status of research in the aspect of heating, cooling, ventilation, sanitation and building environments. The conclusions are as follows. (1) The research trends of fluid engineering have been surveyed as groups of general fluid flow, fluid machinery and piping, etc. New research topics include micro nano fluid, micropump and fuel cell. Traditional CFD was still popular and widely used in research and development. Studies about fans and pumps were performed in the field of fluid machinery. Characteristics of flow and fin shape optimization are studied in the field of piping system. (2) The research works on heat transfer have been reviewed in the field of heat transfer characteristics, heat exchangers, and desiccant cooling systems. The research on heat transfer characteristics includes thermal transport in pulse tubes, high temperature superconductors, ground heat exchangers, fuel cell stacks and ice slurry systems. For the heat 'exchangers, the research on pin-tube heat exchanger, plate heat exchanger, condensers and gas coolers has been cordially implemented. The research works on heat transfer augmenting tubes have been also reported. For the desiccant cooling systems, the studies on the design and operating conditions for desiccant rotors as well as performance index are noticeable. (3) In the field of refrigeration, many papers were presented on the air conditioning system using CO2 as a refrigerant. The issues on the two-stage compression, the oil selection, and the appropriate oil charge were treated. The subjects of alternative refrigerants were also studied steadily. Hydrocarbons, DME and their mixtures were considered and various heat transfer correlations were proposed. (4) Research papers have been reviewed in the field of building facilities by grouping into the researches on heat and cold sources, air conditioning and air cleaning, ventilation and fire research including tunnel ventilation, flow control of piping system, and sound research with drain system. Main focuses have been addressed to the promotion of efficient or effective use of energy, which helps to save energy and results in reduced environmental pollution and operating cost. (5) Studies were mostly focused on analyzing the indoor environment in various spaces like cars, old tombs, machine rooms, and etc. in an architectural environmental field. Moreover, subjects of various fields such as the evaluation of noise, thermal environment, indoor air quality and development of energy analysis program were researched by various methods of survey, simulation, and field experiment.