• 설비공학논문집
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• 제8권4호
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• pp.463-472
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• 1996

Experiments were carried out to study the operation characteristics of a regenerator with a thermo-syphon pump and a surface-flame burner for a lithium bromide (LiBr)-water absorption heat pump. A cylindrical-shape metal-fiber burner and commercial grade propane were used. The emission of carbon monoxide and nitric oxide was measured by a combustion gas analyzer. Ther regeneration rate of water vapor as a refrigerant was measured. It could be as a reference value showing the performance of the regenerator. The circulation rate of the LiBr-water solution was also measured from both the tanks for the weak-and the strong-solution. Using a refractometer, the LiBr concetration in the solution was calculated from the measured refractory index of the solution. Temperature of the solution and the condensed water was recorded at several points in the experimental apparatus with thermocouples, using a personal computer. This data collecting system for measuring temperature was calibrated with a set of standard thermometers. The generating rate of water vapor as refrigerant increased linearly with heat supplied. It was about 4.0g/s with the heat supplied at a rate of 16,500kcal/h. The circulation rate of LiBr solution also increases with the heat supplied. The difference in LiBr concentrations between the weak and the strong solution was in the range of 1 to 5% when the concentration of the strong solution was about 60%. It was dependent upon both the heat supplied and the circulation rate of the solution. The initial concentration and the level of the LiBr solution in the regenerator were measured and recorded before experiments. The effect of them on the generating rate of water vapor and the circulation rate of the solution was also studied. The generating rate of water vapor was not strongly dependent upon both the level of the LiBr solution and the initial LiBr concentration. However, the concentration difference of the solution increases with the initial level of the LiBr solution.

• 생물환경조절학회지
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• 제14권4호
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• pp.263-268
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• 2005

실과용으로 적합한 양액종류를 선발하고자 수경재배용으로 선발한 '금장외대파'와 '토쿄구로파'을 공시하여 담액식으로 시험을 수행하였다. 양액종류로 기존 파용 지바농시액, 엽채소용 M식액, 파용 타케가와액, 및 싹파용 야마자키액을 이용하여 시험한 결과, 구당 생체 중 및 건물중에 있어서 두 품종 모두 야마자키액, M식액, 지바농시액, 타케가와액 순으로 양호하였다. 생체중과 건물중 증가, 그리고 양분 흡수율 및 기타 요인을 모두 고려하였을 때 실파 수경재배용으로 가장 적정한 배양액으로 싹파용 야마자키액을 선발하였다.

• Restorative Dentistry and Endodontics
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• 제28권5호
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• pp.425-430
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• 2003

The purpose of this study was to evaluate the clinical applications of the Sodium Dichloroisocyanurate effervescent tablet as a routine root canal irrigant by performing several in vitro tests such as $Cl^{-}$ content. cytotoxicity. antimicrobial effect as well as its pH level compared to the equivalent concentration of sodium hypochlorite solution. 1. Sodium Dichloroisocyanurate demonstrated lower level of $Cl^{-}$ concentration than each dilution of sodium hypochlorite solution. Both solution has increased level of $Cl^{-}$ as the concentration of each solution increased. There was no significant change of $Cl^{-}$ concentration in sodium hypochlorite as time goes by. However. $Cl^{-}$ concentration in Sodium Dichloroisocyanurate was increased. 2. The antimicrobial effects of both solutions were increased when their concentrations were increased. One day after dilution. antimicrobial effect of Sodium Dichloroisocyanurate was slightly higher than sodium hypochlorite. however. there was no difference in 1 week dilution solution. One month dilution solution of sodium hypochlorite still retain its activity. but antimicrobial effect of Sodium Dichloroisocyanurate was drastically decreased 1 month after dilution. 3. The cytotoxicity of Sodium Dichloroisocyanurate was rather higher than same concentration of sodium hypochlorite solution until 1 week after dilution. Then in 1 month. cytotoxicity of Sodium Dichloroisocyanurate was decreased than that of 1 week dilution solution. especially 4% Sodium Dichloroisocyanurate solution has almost no toxicity. However. 1% and 2% sodium hypochlorite solution has unchanged moderate degree of cytotoxicity after the dilution. Furthermore. 4% sodium hypochlorite solution showed high level of toxicity. 4. The pH level of Sodium Dichloroisocyanurate showed that the solution was weak acid (pH5). On the other hand. sodium hypochlorite was revealed as a strong alkaline solution (pH12). There was no change in pH following the dilution of each solution. As results. Sodium Dichloroisocyanurate solution fully satisfy the basic requirements as a root canal irrigation solution. However. we strongly recommend to use this solution clinically in low concentration and try to apply into the root canal within 1 week after dilution.

• Journal of applied mathematics & informatics
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• 제16권1_2호
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• pp.279-287
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• 2004

In this paper, we establish relations between a solution of a vector continuous-time program and a solution of a vector variational-type inequality problem with functionals.

• 농업과학연구
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• 제41권4호
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• pp.399-404
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• 2014

Soil moisture is an important factor for the availability and circulation of nutrients in arable soil. The purpose of this study was to set thresholds moisture content on soil nitrate concentration in the solution for real-time diagnosis. Sandy loam, silt loam, and sandy loam was filled with $1.2g\;cm^{-3}$ at Wagner pots, 0, 100, and $200mg\;L^{-1}$ of $KNO_3$ was saturated. Nitrate in standard solution was recovered about 95% by passing the porous cup. Nitrate concentrations in sampling of soil solution were examined by using a porous cup. The soil solution was higher in accordance with sandy loam> silt loam> clay loam, limited water filled pore space for sampling soil solution was 33.7, 56.4, and 62.2%, respectively. Nitrate concentration in the soil solution was negligible at sandy loam and silt loam during sampling periods, which was decreased about 50~82% in clay loam compared to the initial $NO_3$-N concentration in the saturated $KNO_3$ solution. Over limitation of soil solution sampling, soil EC and $NO_3$-N content were increased with the saturated $NO_3$-N concentration, regardless of soil texture (p<0.05). Conclusively, soil solution by using a porous cup was possible, regardless of the soil texture, which was useful for the diagnosis in nitrate concentration of soil solution. However, because nitrate concentration of soil solution in a clay loam changes, it was necessary for careful attention in order to take advantage for the real-time diagnosis of nitrogen management in soil.

• International Journal of Industrial Entomology and Biomaterials
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• 제24권1호
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• pp.29-35
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• 2012

Bumblebees are widely used to pollinate various crops, especially tomato, in greenhouses and fields. Here, we investigated whether different sugar solutions have any effects on the oviposition and colony development of Bombus terrestris queens. The types of sugar solution used were a white sugar solution, brown sugar solution, dark brown sugar solution, and prepared sugar solution; all solution contained with a 40% sugar concentration and 0.3% sorbic acid. Among these sugar solutions, B. terrestris queens reared on the white sugar solution exhibited the best results; the rates of oviposition, colony foundation and progeny-queen production were $75.0{\pm}11.0$, $33.0{\pm}9.6$ and $21.7{\pm}7.3$, respectively, which corresponded to 1.1-33.0-fold increases over the results of other sugar solutions. Queens reared on the prepared sugar solution did not found any colonies. The death rate within one month was lowest for the queens reared on the white sugar solution at $26.1{\pm}10.9%$, which was 1.2-2.0-fold lower than the rate for the other sugar solutions. Furthermore, the numbers of progeny produced by queens reared on the white sugar solution, $131.4{\pm}38.8$ workers and $51.0{\pm}40.6$ queens, were also higher, corresponding to 1.1-1.2-fold increases compared to queens raised on the other sugar solutions. Therefore, the white sugar solution was the favorable sugar solution for the egg-laying and colony developmental characteristics of B. terrestris queens.

• 생물환경조절학회지
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• 제14권3호
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• pp.174-181
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• 2005

Experiments were carried out to develop an optimal nutrient solution for the single-stemmed rose (Rosa hybrida L.) 'Red velvet' in a closed aeroponic system. Plants were grown in 1/3, 1/2, 1, or 3/2 strength of the nutrient solution of National Horticultural Research Station in Japan (NHRS). Significantly less changes of pH and EC ($dS{\cdot}m^{-1}$) in the drainage were observed in 1/2 strength treatment as compared to other treatments. The $NO_3-N$, K, Ca, and Mg concentrations in the drainage solution of 1/2 strength treatment were maintained at optimal levels. These results indicated that the rose uptakes of both nutrients and water was more stable than those in other concentration. The concentration of macronutrients in nutrient solution were adjusted based on the ratio of nutrient:water (n/w) taken up by plants grown in the 1/2 strength solution. The composition of the new solution (classified the University of Seoul (UOS) solution) was as follow; $NO_3-N$ 8.8, $NH_4-N$ 0.67, P 2.0, K 4.8, Ca 4.0, Mg 2.0 $me{\cdot}L^{-1}$. To further evaluate new solution on crop growth, the rose 'Red Velvet' was grown again in l/2, 1, and 2 strength UOS solution to compare with 1.0 strength PBG (proefstion voor bloemisterij en glasgroenpe) solution. Overall the plant growth, including the stem length and number of five-leaflet leaves was higher in 1.0 strength of UOS solution than other treatments. Results presented in this study indicate that the nutrients in the UOS solution are well balanced for the single-stemmed rose in the closed aeroponic system.

• Journal of Yeungnam Medical Science
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• 제23권1호
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• pp.19-25
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• 2006

심실중격결손이나 심방중격결손과 같이 대동맥 차단시간이 길지 않은 질환에 있어서는 HTK용액의 심근보호효과가 냉혈심정지액과 비슷한 효과를 가짐을 알 수 있었다. 따라서 한번 투여로 2~3시간의 수술이 가능한 장점을 가진 HTK용액을 소아에서도 유용하게 사용할 수 있을 것으로 생각되며 향후 복잡심기형과 같은 긴 대동맥차단이 요구되는 소아환자의 안정성에 대해서는 더 많은 연구가 필요할 것으로 생각된다.

• Corrosion Science and Technology
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• 제4권2호
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• pp.45-50
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• 2005

A 3% NaCl solution of 1 $dm^3$ circulated with 1.5 $dm^3/min$ by a pump for 24 h in the presence of magnetic field. An iron plate immersed in a $100cm^3$ of test solution for 24 h. The rest potential and pH on surface fixed after 3 h. Containing 0~120 ppm of Fe(II) ion, the dissolution in the magnetically treated solution rose comparing with that in the non-magnetically treated solution. The dissolution amount reached to maximum at 50 ppm, then fixed in the non-magnetically treated solution. When Fe(II) ion existed in the magnetically treated solution, dissolution accelerated a little. In the non-magnetic treated solution containing 10~125 ppm of Fe(III) ion existed, the dissolution accelerated. The dissolution amounts reached to maximum at 50 ppm, then decreased from maximum value. In the magnetically treated solution, the dissolution amounts reached to minimum until 50 ppm, then increased from minimum value. The dissolution amounts affected larger with increasing of magnetic flux density. Fe(II), Fe(III) ions and magnetic treatment affected to formation of $Fe(OH)_2$ and/or $Fe_3O_4$ films. The magnetically treated effects memorized about one month.

• 대한기계학회논문집B
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• 제26권9호
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• pp.1241-1248
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• 2002

Performance extension of the absorption refrigerator with LiBr solution is often faced to operate very close to the crystallization limit. Especially in the development of an air-cooled cycle, the crystallization of working solution in the system is a very difficult problem to overcome. This paper describes the cycle of hot water driven absorption system using a new working absorption solution instead of LiBr solution to improve the efficiency. In this study, we found out the characteristics of new working absorption solution through the cycle simulation and compared LiBr solution to evaluate. The effect of cooling water temperature, weak solution flow rate, hot water temperature and hot water flow rate were also examined. The COP is increased 22% higher in the case of LiBr＋Li1＋LiC1＋LiNO$_3$＋$H_2O$, 2% LiBr＋HO(CH$_2$)$_3$OH＋$H_2O$ than that of LiBr solution for the same operation condition.