• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.2
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• pp.21-27
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• 2013

The present study explored the way to desalinate seawater for agricultural irrigation using forward osmosis (FO) process using liquid fertilizer as draw solution. FO experiments were performed in a cross flow mode using flat sheet FO membrane. The effect of membrane orientation, flow rate, and draw solution concentration on the performance of forward osmosis was investigated by measuring water flux of forward osmosis membrane. The water flux when the draw solution was placed against the membrane active layer was lower than the water flux when the feed solution was placed against the membrane active layer. This results indicated that the decrease of effective osmotic pressure by dilutive internal concentration polarization was less than that by concentrative internal concentration polarization. Increasing flow rate from 66.7 to 133.1 $cm^3$/min resulted in increase of the water flux when the membrane active layer orient to draw solution and feed solution, respectively. The reduction of resistance to water flow increased water flux at higher flow rate. The water flux of FO membrane increased with increasing draw solution concentration from 10000 to 30000 mg/L. The water flux for $KH_2PO_4$ draw solution was similar to that for commercial fertilizer. Optimization of FO process would contribute to economically desalinate brackish water for agricultural use.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.8 no.4
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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.

• Journal of Environmental Health Sciences
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• v.22 no.1
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• pp.1-4
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• 1996

I have conducted two testings to find out which water is better for drinking water. First, I made 20 mM L-DOPA solutions by solving L-DOPA (3,4-Dihydroxyphenylalanine) in tap water, Waters' mineral water and reverse osmotic water. Then I measured activities after adding Tyrosinase (purifide enzyme, step 3), which was extracted from Salanum melongena(mad apple), in each L-DOPA solution. Second, I solved 0.1, 0.5 and 0.9% salt in each 20 mM L-DOPA distilled water to measure activity of each salt solution. The results of the testings are as follows: 1. 10 minutes after adding Salanum melongena(mad apple) tyrosinase in each L-DOPA solution, activity of Waters' mineral water was 0.867 tap water 0.777 and reverse osmotic water 0.742. 2. Activity of Waters' mineral water was higher than that of tap water by 10.4% and higher then reverse osmotic by 14.4%. 3. Activity of Waters' mineral water was much higher than that of 0.9% salt water by 41.8%. 4. The optimum pH of Salanum melongena (mad apple) tyrosinase is 9.0. Most enzymes working in the human metabolism are alkaline and body fluids' pH also alkaline. In conclusion, an alkaline water is believed better than an acidic water for drinking.

• Journal of the Korean Institute of Gas
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• v.2 no.4
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• pp.47-52
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• 1998

Water vapor absorption performance of four components solution ($LiBr+LiNO_3+LiC1+H_2O$) which could be substituted for commonly used $LiBr/H_2O$ solution in water cooled abosorption chiller is tested using a vertical tube absorber. Inlet solution concentration, inlet solution temperature, solution flow rate and inlet temperature of cooling water is varied as experimental parameters. The results of the experiment of water vapor absorption performance show that four components solution should have $2\%$ higher concentration for equal absorption capacity of $LiBr/H_2O$. But considering that four components solution have higher solubility than LiBr solution about $3\%$ high oncentration, four components solution ($LiBr+LiNO_3+LiC1+H_2O$) have more absorption capacity than LiBr solution in actual absorption chiller and can be applied to a small or air cooled absorption chiller.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.131-136
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• 1997

It is well known that concrete is typical porous material. We pay attention to Hansen's idea that concrete may be expected to act as semi-permeable membrane, and report the effect of concentration of solution and temperature on water flux in forward osmosis. In order to measuring volume of water flux from distilled water to solution of sodium chloride through hardened cement paste, specially designed apparatus was constructed, and the following result were obtained: (1) hardened cement paste acts as semi-permeable membrane, consequently, water flux in forward osmosis may occur. (2) Rate of water flux is proportion to concentration of dilute solution, and this suggests hardened cement paste is agreeable to the theory of membrane. (3) Effect of temperature on water flux is agreeable to Arrehenius equation and is great.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.5
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• pp.422-430
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• 2001

In the present study, an evaporative generation process of ammonia-water solution film on the vertical plate was analysed. For the utilization of waste heat, hot water of low temperature was used as the heat source. The continuity, momentum, energy and diffusion equations for the solution film and vapor mixture were formulated in integral forms and solved numerically. Counter-current solution-vapor flow resulted in the refrigerant vapor of the higher ammonia concentration than that of co-current flow. Eve the rectification of refrigerant vapor was observed near the inlet of solution film in counter-current flow. For the optimum operation of generator using hot water, numerical experiments, based on the heat exchange and generation efficiencies. revealed the inter-relationships among the Reynolds number of the solution film and hot water, and the length of generator. Enhancement of heat and mass transport in the solution film was found to be very effective for the improvement of generation performance, especially at high solution flow rate.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.9
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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.

• Korean Journal of Medicinal Crop Science
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• v.19 no.6
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• pp.464-471
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• 2011

Conventional Thiamine Dilauryl Sulfate (TDS) powder has a low stability. In order to solve this problem, this study was performed to improve the solubility of TDS. The process for enhance solubility of TDS was nano grinding mill and ultrasonic dispersion process. TDS paticle was manufactured to nano size through nano grinding mill process. The size of TDS nanoparticle was measured as average 220 nm by DLS. And The TDS nanoparticle in water solution manufactured through ultrasonic dispersion process. The TDS nanoparticle in water solution was showed the highest solubility with 40% ethanol. These results was increased the concentration of TDS from 200 ppm to 240 ppm in water solution. The TDS nanoparticle in water solution showed diameter of Colletotrichum gloeosporioides growth with smaller than about 1.56 cm compared to the TDS paticle in water solution at same concentration. Also, TDS nanoparticle in water solution showed growth inhibition activity as 59.2% with higher than about 10% compared to the TDS paticle water solution in same concentration. Finally, TDS nanoparticle in water solution was increased solubility through nano grinding mill and ultrasonic dispersion process. Also, the increase of concentration in TDS nanopaticle in water solution according to solubility enhancement lead to an result enhancement of antifungal activity. Consequently, we suggested that the TDS nanoparticle in water solution was more effective than TDS particle in water solution owing to the sub-cellular particle size, ability to persistence and targeting to cell membrane of Colletotrichum gloeosporioides. Furthermore we expected the applicating possibility with bio pesticide.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.83-84
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• 2016

For the slip resistance test of shower room floor, the "O-Y Pull Slip Meter method (O-Y·PSM)" regulated under KS M 3510. This test method uses cooking oil as a substitute of soapy water, and thus it does not reflect the real condition. In this study, on 10 types of floor material samples, the Coefficient of Slip Resistance Bath (CSR·B) on bare foot between 10 types of body wash solution and 6 types of SDS solution was compared. The body wash solution is a mixture of soap and water in 1:20 ratio. As a result, SDS 0.1% solution was the most suitable for a substitute of soapy water in shower.

• Journal of the Korean Solar Energy Society
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• v.24 no.1
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• pp.53-61
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• 2004

Absorption potential of desiccant solution significantly decreases after absorbing moisture from humid air, and a regeneration process requires a great amount of energy to recover absorption potential of desiccant solution. In an effort to develop an efficient solar water heater, this study examines a regeneration process using hot water obtained from solar water heater to recover absorption potential by evaporating moisture in the liquid desiccant. In this paper, a solar absorption dehumidifying system with solar water heater is suggested to save the electricity for operating an air conditioner. LiGl(lithium chloride) solution was adopted as a liquid desiccant in the proposed system, and hot water obtained from the solar water heater was used for regenerating the liquid desiccant. As a result, it was clear that the dilute LiCl solution could be regenerated by hot water, and the regeneration rate depends mostly on temperature level of liquid desiccant. The regeneration rates were about 2.4kg/h with $40^{\circ}C$, 4.0kg/h with $50^{\circ}C$, and 6.2kg/h with $60^{\circ}C$ of hot water respectively.