• 대한기계학회논문집B
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• 제24권8호
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• pp.1085-1096
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• 2000

An experimental study was performed to examine the heat and mass transfer characteristics of $LiBr-H_2O$ solution flowing over a single horizontal tube with the water vapor absorption. Effects of the flow rate and the temperature of the solution at the top of the tube, the absorber pressure and the drainage pattern were considered. The absorption rate depends highly on the absorber pressure at the low flow rate condition while on the solution inlet temperature at the high flow rate condition. Also, when the flow rate is low, the absorption performance with the sheet flow drainage appeared to be higher than that with the dripping/jet drainage. However, at the high flow rate condition, the case became reversed. The liquid film became wavy with the higher absorption rate. The waves were more probable to form with the lower flow rate and temperature of the solution, and with the higher absorber pressure.

• 한국응용곤충학회지
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• 제23권1호
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• pp.37-41
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• 1984

선창내 온도가 $10\~20^{\circ}C$에서 $1m^3$당 메칠브로마이드 25g을 투약하여 24시간 훈증소독하면 채집된 원대부착해충과 쌀바구미는 $100\%$죽으며 직경 30cm 회전속도 1,800rpm 이상의 교반기 2태를 설치하고 DT적에 의하여 계산한 37.5g을 투약한 후 16시간 훈증소독을 하여도 24시간 처리와 동일한 살충효과를 얻었다. 가스농도가 균일화되는 데는 교반기를 사용하지 않으면 $4\~6$시간 걸리고 교반기를 사용한 경우는 $1\~3$시간으로 단축되었다.

• 한국태양에너지학회 논문집
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• 제27권4호
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• pp.19-26
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• 2007

This paper concerns the study of absorption refrigeration and heat pump cycle to use sewage. Simulation analysis on the double-effect absorption refrigeration cycle with parallel and two-stage heat pump cycle has been performed. The working fluid is Lithium Bromide and water solution. The absorption refrigeration cycle use sewage as a cooling water for the absorber and condenser, and absorption refrigeration cycle does that as a chilled water for the evaporator of the first stage cycle. And the two-stage cycle consists of coupling double-effect with parallel and single effect cycle so that the first stage absorber and condenser produces heating water to evaporate refrigerant in the evaporator of the second stage. The effects of operating variables such as a absorber temperature on the coefficient of performance have been studied for absorption refrigeration and heat pump cycle.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2434-2439
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• 2008

This paper was studied on the cavitation instability of a Solution Pump Inducer in an absorption chiller-heater. Inlet pressure of LiBr and rotational speed at nominal mode are 2,800 Pa and 3,500 rpm respectively. Due to the marginal operation of available NPSH, the cavitation performance of the inducer is critical for the stable operation without the deterioration of head performance. In the study, cavitation performance and its mode of instability was investigated experimentally. Water was used as the working fluid and the test inducer was scaled up as 1.75 times for detail measurements and flow visualization. Inlet pressure was controlled by a vacuum pump. This research focused on types of cavitation instability and phenomena to investigate the possibility of harmful damage due to cavitation instability. Casing wall pressure and instantaneous inlet pressure was measured to observe the unsteady flow characteristics. Through the visualization and spectrum analysis of pressure, the occurrence region and intensity of asymmetric cavitation and cavitation surge are analyzed in the test inducer.

• 설비공학논문집
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• 제11권6호
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• pp.835-845
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• 1999

The objective of the present study was to investigate heat and mass transfer characteristics in a vertical falling film type absorber using LiBr-$H_2O$ solution with 6owt%. The experimental apparatus consisted of an absorber with inner diameter of 17.2 mm and length of 1150mm, a generator, an evaporator/condenser, a solution tank, a sampling trap etc. The parameters were solution temperature of 45 and $50^{\circ}C$, coolant temperature of 30 and $35^{\circ}C$, and film Reynolds numbers from 50 to 150. Pressure drop in the absorber increased as solution and coolant temperatures decreased. Pressure drop in the absorber increased up to the film Reynolds number of 90, and then decreased at the further increase of the Reynolds number above 90. The maximum absorption mass flux observed at the film Reynolds number of 90. Absorption mass flukes increased as coolant temperature decreased. Absorption mass fluxes and heat transfer coefficients under subcooled condition were larger than those under superheated condition. Heat transfer coefficients were affected by solution temperature more than coolant temperature. The maximum absorption effectiveness under the subcooled condition was 23% for coolant temperature of $30^{\circ}C$ and 31% for coolant temperature of $35^{\circ}C$ under the present experimental conditions.

• Journal of Applied Biological Chemistry
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• 제57권2호
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• pp.141-144
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• 2014

국가간 농산물의 수출입 검역시 새로운 기술로 인정받고 있는 전자빔 조사시 귤가루깍지벌레와 복숭아혹진딧물의 방제효과를 조사한 결과, 저선량의 전자선 조사(30, 60, 90 및 120 Gy)는 복숭아혹진딧물과 귤가루깍지벌레의 직접적인 방제효과는 나타나지 않았으나, 발육 및 생식 억제에 크게 영향을 끼쳐 해충에 대한 불활성화 효과를 나타내었다. 이 같은 결과는 국가간 농산물 수출입 검역현장에서 전자선 조사기술이 메틸브로마이드와 같은 화학적 병해충 방제를 대체할 새로운 가능성을 확인해 주는 결과이다.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.46-51
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• 2006

In order to utilize the refrigerants condensation heat of condenser on the absorption chiller system, the solution cooling condenser(SCC) were proposed, which weak solution of absorber outlet use as a cooling water. As the UA of the solution cooling condenser increased, increasement of COP is about maximum 0.09 in occasion of single effect and is about maximum 0.08 in occasion of double effect series flow. In the case of heat exchanger efficiency is about 0.85, it's increments are 0.08 and 0.072, each. And solution cooling condenser is a more effective device in the single effect absorption system more than double effect system for the principle of operation. In order to increases the heat of solution cooling condenser, if reduce the flow rate of cooling water or the value of UA, it makes COP increase a little, but it brought COP decrease because of increasing the pressure of system.

• 설비공학논문집
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• 제12권3호
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• pp.267-276
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• 2000

A numerical study has been carried out to find out the optimal design condition of a solar absorption cooling system. The system was composed of solar collectors and an absorption chiller with LiBr/water The System performance with commercial single effect(SE) cycle and a new single effect/double lift(SE/DL) cycle utilizing low temperature hot water was calculated and compared. It was found that the required solar collector area grew exponentially as the overall heat loss coefficient of solar collectors increased. For instance, the required area for cooling capacity of 1 USRT was $17m^2$ if heat loss coefficient was 4 W/$m^2\;cdot\;K$. If heat loss coefficient was doubled($8\;W/m^2\;cdot\;$K), the required collector area was increased by 6 times($100m^2$) .It was also found that the SE-cycle as the heat loss coefficient of solar collectors increased. Generally, a SE/DL-cycle seems to be more advantageous than a SE-cycle if loss coefficient of solar collector is greater than 4 W/$m^2\;cdot\;K$.

• 박물관보존과학
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• 제1권
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• pp.43-51
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• 1999

문화재의 생물피해 예방에 주로 활용되는 훈증소독(燻蒸消毒)[메틸브로마이드와 에틸렌옥사이드 혼합가스]이 서화류(書畵類)에 어떤 영향을 미치는지에 대하여 간략한 조사(調査)를 실시하였다. 채색(彩色)이 있는 조선시대 고지도(古地圖)와 회화(繪畵)등 13점을 대상으로 훈증소독 전(前)과 후(後)의 안료(顏料)의 변색(變色) 또는 퇴색(退色)의 유무(有無) 그리고 종이의 pH변화 등에 대여 측정(測定)하였다. 그 결과(結果) 기존(旣存)의 문화재 훈증소독 적용기준(適用基準)[가스의 농도(濃度), 폭로(暴露)시간 등]을 지킨 조건에서는 안료의 변·퇴색현상을 발견하지 못했으며 종이의 산성화(酸性化)에도 영향을 미치지 않는 것으로 확인되었다.

• 대한화학회지
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• 제56권2호
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• pp.188-194
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• 2012

양이온성 계면활성제인 TTAB(tetradecyltrimethylammonium bromide) 용액에서 4-알킬벤조산 이성질체들의 가용화 현상을 UV/Vis 분광법을 이용하여 연구하였다. 온도변화에 따른 가용화상수($K_s$)값과 임계미셀농도(CMC)값의 변화를 측정함으로써 열역학적으로 분석하였다. 모든 이성질체들의 가용화에 대한 ${\Delta}G^o{_s}$ 값은 측정범위 내에서 모두 음의 값을 나타내었으며, ${\Delta}H^o{_s}$와 ${\Delta}S^o{_s}$ 값은 모두 양의 값을 나타내었다. 또한 4-알킬벤조산 이성질체들의 가용화현상에 미치는 n-부탄올과 NaCl의 효과에 대하여서도 조사하였다. 이러한 첨가제들은 $K_s$와 CMC 값을 동시에 큰 폭으로 변하게 하였으며, 그 결과 4-알킬벤조산 이성질체들은 미셀 속의 중심부 혹은 깊은 palisade 영역에서 가용화되는 것으로 예측할 수 있었다.