• ALGAE
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• 제37권4호
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• pp.301-316
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• 2022

The red alga Compsopogon caeruleus can generally be found in tropical and subtropical waters worldwide. In addition to its natural habitats, this species may be found in waters that receive abnormally hot water, e.g., from powerhouses. To date, the presence of C. caeruleus has not been observed in thermally polluted lacustrine ecosystems in Poland, which has a moderate climate. The thalli of this red alga were found growing on Vallisneria spiralis in Lichenskie Lake. Importantly, this paper presents a previously unknown relationship between the temperature (20, 25, 30, 35, and 40℃) and oxygen requirements of C. caeruleus (based on ex situ measurements of O₂ consumption by thalli). Surprisingly, 35℃ can be the optimum temperature for C. caeruleus, and this temperature is higher than the values reported by some previous thermal analyses by approximately 10℃. Additionally, we reviewed and mapped the distribution of this nonnative and mesophilic red alga in natural / seminatural water ecosystems in Europe. Finally, we propose that the occurrence of C. caeruleus mature thalli can be a novel, simple and easy-to-recognize bioindicator of artificially and permanently heated waters in moderate climate zones by a regular discharge of postindustrial water.

• Fibers and Polymers
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• 제5권3호
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• pp.213-218
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• 2004

Low temperature plasma (LTP) treatment using oxygen gas was applied to a wool fabric. The LTP treated wool fabric was tested with several methods: ASTM D5035-1995, ASTM D1424-1996, AATCC Test Method 99-2000, AATCC Test Method 61-2001 lA, AATCC Test Method 15-2002 and AATCC Test Method 8-2001 and the results were compared with the industrial requirements (ASTM D3780-02 and ASTM D4155-0l). The results revealed that the LTP treated wool fabric could fulfil the industrial requirements. The results of the investigation were discussed thoroughly in this paper.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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• pp.211-215
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• 2004

For design of cryogenic propellant feeding system, one of the main requirements is to meet temperature requirement for satisfying turbo-pump NPSH requirement. In this paper improved method of estimating the thermal stratification in liquid oxygen tank is presented to help design. In the case of liquid rocket using turbo-pump, the inner pressure of liquid oxygen tank is maintained low, so vaporization of liquid oxygen is generally occurred. In this paper, inner process of LOX tank is analyzed by two phase flow modeling. The vaporization rate and required helium mass is investigated.

• 한국지역사회생활과학회지
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• 제27권3호
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• pp.419-435
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• 2016

The purpose of the present study was to suggest the design requirements for Korean naval duty uniforms by evaluating the physiological and psychological comfort while wearing the uniforms. Two sets of wear trials were conducted with summer uniforms(eight young males) and winter uniforms(seven other young males). The summer wear trial consisted of 10-min rest, 60-min exercise, and 10-min recovery at an air temperature($T_{air} $) of $33^{\circ}C$ and 62%RH, followed by 10-min recovery at a $T_{air} $ of $23^{\circ}C$ and 64%RH(total 90 min). The winter wear trial consisted of 20-min rest at $T_{air} $ $20^{\circ}C$ and 55%RH, 25-min rest, 30-min exercise, and 35-min recovery at a $T_{air} $ of 0oC and 43%RH(total 110 min). Rectal and seven skin temperatures, clothing microclimate, heart rate, oxygen consumption, total sweat rate, and subjective perceptions were measured during the wear trials. By evaluating the experimental results from the wear trials, we extracted the following psycho-physiological design requirements to improve the current Korean naval uniforms: (1) It is important to maintain the skin temperatures within their comfort range, which depends on the body region (higher than $30^{\circ}C$ in winter, but less than $35^{\circ}C$ in summer). (2) In summer, the feet should be protected from the high heat of the ship floor surface. (3) In summer, sweat from the back should be sufficiently absorbed and allowed to dry quickly.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.255-255
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• 2011

Zinc oxide based thin films have been extensively studied in recent several years because they have very interesting properties and zinc oxide is non-poisonous, abundant and cheap material. ZnO films are employed in different applications like transparent conductive layers in solar cells, protective coatings and so on. Wide industrial application of the ZnO films requires of development of cheap, effective and scalable technology. Typically used technologies don't completely satisfy the industrial requirements. In the present work, we studied effect of the deposition parameters on the structure and properties of ZnO films deposited by DC arc plasmatron. The varied parameters were gas flow rates, precursor composition, substrate temperature and post-deposition annealing temperature. Vapor of Zinc acetylacetone was used as source materials, oxygen was used as working gas and argon was used as the cathode protective gas and a transport gas for the vapor. The plasmatron power was varied in the range of 700-1500 watts. Flow rate of the gases and substrate temperature rate were varied in the wide range to optimize the properties of the deposited coatings. After deposition films were annealed in the hydrogen atmosphere in the wide range of temperatures. Structure of coatings was investigated using XRD and SEM. Chemical composition was analyzed using x-ray photoelectron spectroscopy. Sheet conductivity was measured by 4-point probe method. Optical properties of the transparent ZnO-based coatings were studied by the spectroscopy. It was shown that deposition by a DC Arc plasmatron can be used for low-cost production of zinc oxide films with good optical and electrical properties. Increasing of the oxygen content in the gas mixture during deposition allow to obtain high-resistive protective and insulation coatings with high adhesion to the metallic surface.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2009년도 춘계학술대회 논문집
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• pp.7-10
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• 2009

우주발사체용 액체추진제 로켓엔진을 시동할 때 사용되는 터보펌프 시동기에 적용하고자 고체추진제 개발 및 특성 평가를 수행하였다. 터보펌프 시동기용 추진제의 배출가스는 기계적인 부식 또는 대기오염 등의 이유로 화염온도가 낮아야 하고 고체입자 잔사 및 독성이 적은 것이 바람직하며, 작동시간이 어느 정도 유지가 되어야 하기 때문에 비교적 낮은 연소속도가 필요하다. 본 연구에서는 PCP계열의 바인더를 사용하고 oxygen balance나 점화성에서 유리한 DHG(Dihydroxy glyoxime)을 냉각제를 사용하는 추진제 조성을 개발하여 연소속도와 기계적 물성 등의 특성평가를 실시하였으며, 최종적으로는 지상연소시험을 통하여 터보펌프 시동기의 성공적인 개발 가능성을 입증하였다.

• 한국수소및신에너지학회논문집
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• 제16권3호
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• pp.229-237
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• 2005

A new burner configuration for a compact fuel-cell reformer with a high-temperature air combustion concept was numerically studied. The burner was designed for a 40 $Nm^3/hr$ hydrogen-generated reformer using natural gas-steam reforming method. In order to satisfy the primary requirements for designing a reformer burner (uniform distribution of temperature along the fuel processor walls and minimum heat losses from the reformer), the features of the present burner configuration included 1) a self-regenerative burner for an exhaust-gas-recirculation to apply for the high-temperature air combustion concept, and 2) an annular-type shield for protecting direct contact of flame with the processor walls. For the injection velocities of the recirculated gas of 0.6-2.4 m/s, the recirculated gas temperature of 1000 K, and the recirculated oxygen mole fraction of 4%, the temperature distributions along the processor walls were found uniform within 100 K variation. Thus, the present burner configuration satisfied the requirement for reducing temperature gradients along the processor walls, and consequently demonstrated that the high-temperature air combustion concept could be applied to the practical fuel reformers for use of fuel cells. The uniformity of temperature distribution is enhanced as the amount of the recirculated gas increases.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.220.2-220.2
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• 2011

Biodiesel and biodiesel blend fuel are receiving increasing attention as alternative fuels for diesel engines without substantial modifications. Biodiesel fuels and blending have been widely studied and applied in diesel engine because of biodiesel's lower sulfur, lower aromatic hydrocarbon and higher oxygen content. Biodiesels have the potential to be oxidized in different condition. It has reported that oxidation deterioration of biodiesel is different in the condition of storage and oxidation causes chemical property change of methyl esters. Sunlight intensity, temperature, material of container and contact surface with oxygen are key dominant factors accelerating oxidation deterioration. In this study, we chose temperature among key oxidation conditions and metal container filled with biodiesel was heated at about $110^{\circ}C$ for 10 days in order to accelerate oxidation deterioration. To better understand the effect of biodiesel blends on emission, steady state tests were conducted on a heavy duty diesel engine. The engine was fueled with Ultra Low Sulphur Diesel(ULSD), a blend of 10% and 20%(BD10, BD20) on volumetric basis, equipped with a common rail direct injection system and turbocharger, lives up to the requirements of EURO 3. The experimental results show that the blend fuel of normal biodiesel with BD10 and BD20 increased NOx. The result of PM was similar to diesel fuel on BD10, but the result of PM on BD20 was increased about 63% more than its of diesel. The blend fuel of Oxidation biodiesel with BD10 and BD20 increased NOx as the results of normal biodiesel. But PM was all increased on BD10 and BD20. Especially THC was extremely increased when test fuel contains biodiesel about 140% more than its of diesel. Through this study, we knew that oxidation deterioration of biodiesel affects emission of diesel engine.

• 설비공학논문집
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• 제25권1호
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• pp.7-13
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• 2013

Bio Clean Room(BCR) and pharmaceutical product manufacturing facilities require careful assessment of many factors, including HVAC, controls, room finishes, process equipment, room operations, and utilities. Flow of equipment, personnel, and product must also be considered along with system flexibility, redundancy, and maintenance shutdown strategies. It is important to involve designers, operators, commissioning staff, quality control, maintenance, constructors, validation personnel, and the production representative during the conceptual stage of design. Critical variables for room environment and types of controls vary greatly with the clean space's intended purpose. It is particularly important to determine critical parameters with quality assurance to set limits and safety factors for temperature, humidity, room pressure, and other control requirements. In this paper, oxygen cluster ion equipment was utilized in order to enhance the indoor air quality and to prevent the airborne infection of ward in hospital. Moreover, the performance test of the equipment was also performed in order to develop the optimal sterilization system of BCR using the equipment.

• 한국작물학회지
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• 제33권1호
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• pp.97-101
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• 1988

담수 직파 재배시 벼 종자의 발아에 필요한 산소요구도 및 발아 특성을 검토하기 위하여 Japonica 형과 Ind.$\times$Jap. 품종을 공시하여 $25^{\circ}C$와 17$^{\circ}C$의 수온하에서 시험한 결과를 요약하면 다음과 같다. 1. $25^{\circ}C$ 및 17$^{\circ}C$의 수온에서 침종후 용존산소 흡수 및 흡수속도는 Japonica 형인 낙동벼가 Ind.$\times$Jap. 형인 삼강벼에 비하여 컸다. 2. 수분흡수는 침종 2일까지는 품종간 차이가 작았으나 3일후부터 현저한 차이를 나타내어 낙동벼가 보다 더 많이 흡수하였다. 3. 침종후($25^{\circ}C$ 수온) 3일까지의 발아율 및 용존산소 흡수량은 Japonica 형 품종들이 Ind.$\times$Jap. 형 품종들보다 높았다. 4. 발아 및 종자근의 출현까지 $25^{\circ}C$의 수온하에서 Japonica 형 품종들은 각각 3, 4일 Ind.$\times$Jap.형 품종들은 각각 4, 5일이 소요되었으며 Japonica 품종들이 Ind.$\times$Jap.형 품종들 보다 용존산소의 총흡수량이 적어서 발아시 산소요구도가 낮았다. 5. 침종 5일후의 초엽장, 종자근장, 발아율은 Japonica 형 품종들이 Ind.$\times$Jap.형 품종들보다 현저하게 컸다.