• Journal of the Korean Society of Safety
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• v.34 no.3
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• pp.28-35
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• 2019

Dry water is a core-shell structured powder which comprises a very fine water core covered with hydrophobic silica particles. Recently, the dry water has attracted attention as a new type of fire extinguishing agents. However, characteristics of the dry water as a fire extinguishing agent have not been revealed until now. To our best knowledge, this is the first work to uncover effects of particle size of the dry water on the fire extinguishing performance. Pristine dry water, which has heterogeneous particle size distribution, was carefully separated by sieving method into three fractions which were a small size (ca. $110{\mu}m$) fraction, a medium size (ca. $220{\mu}m$) fraction and a large size (ca. $400{\mu}m$) fraction. Microscopic observations confirmed the effective separation of dry water's particle size. In extinguishing tests of wood cribs fire, the medium size dry water showed most excellent fire extinguishing performance, as compared to other dry waters having small (ca. $110{\mu}m$) and large (ca. $400{\mu}m$) particle size. The good performance of the medium size (ca. $220{\mu}m$) dry water may be attributed to the balance between cooling effect of the water core and smothering effect of the silica particles. It is also revealed that small size dry water has poor flowability than large size dry water.

• Journal of Life Science
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• v.9 no.4
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• pp.368-374
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• 1999

Three soybean cultivars, Hwangkeum, Tanyeob and Enrei were planted in the same pot under glasshouse conditions to investigate the influence of the different soil water content such as pF 1.4(wet), 2.1(control) and 3.6(dry) on the transpiration rate, dry matter production and water requirement. The transpiration rate remained the high constant rates under the wet soil condition and the control than the dry condition, and showed a linear correlation between transpiration rate and solar radiation under the all condition of soil water. The transpiration rate highly increased in the morning, but dramatically decreased in the other time in a day. The dry matter production was higher under the conditions of wet soil and the control than that under the dry condition. Also, the dry matter production Tanyeob was higher than other cultivars under all soil water content. The water requirement was higher for Enrei and lower Tanyeob than the control.

• Journal of Environmental Science International
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• v.22 no.2
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• pp.187-193
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• 2013

Dry matter allocation characteristics of Calystegia soldanella, grown in pots, was analysed to assess its plasticity in response to water-stressed conditions. As water was withheld leaf water potential between the two watering treatments was similar during the first 6 days, followed by a rapid decrease in water-stressed plants. The minimum leaf water potential was -1.50 MPa on day 15 and the maximum leaf water potential was about -0.5 MPa on day 0 in water-stressed plants. In well-watered plants leaf water potential was maintained almost consistently throughout the experiment. There was no significant difference in plant dry weight between the two watering treatments for 9 days after the start of experiment and that was remarkably increased thereafter, compared with that remained without any increase in water-stressed plants. In dry mass partitioning, however, the water-stressed plants showed a great plasticity, showing that there were 1.81, 1.35 and 0.81 times increase in root, stem and leaf, respectively. Dry mass partitioning in well-watered plants varied from 2% to 5%. The difference of dry mass partitioning between the two watering treatments was reflected in leaf mass per unit area (LMA) and root/shoot (R/S) ratio. LMA in water-stressed plants was lower than that in well-watered plants, while R/S ratio in water-stressed plants was higher in well-watered plants. This means that the water-stressed plants reduced its leaf area and increased dry mass partitioning into root and stem during the progress of soil drying. These results indicate that Calystegia soldanella inhabiting in sand dune cope with water stress with high plasticity which can adjust its dry mass partitioning according to soil water conditions.

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.6
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• pp.675-684
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• 2000

A novel dry and wet deposition collector, which can overcome the several problems such as water evaporation cartridge cracks and high costs founded in the previous collector systems, has been constructed. ENVI-18 SPE adsorption cartridge has been used to measure atmospheric deposition of polycylic aromatic hydrocarbons (PAHs). A surrogate surface, consisted of water and methanol, was filled in the dry deposition funnel to simulate dry deposition onto water surface. A water supply system in order to compensat evaporation of the surrogate surface was used and it was consisted of a piston pump, a tubing pump, a overflow tube and a chamber system. A novel water vaporizing system to supply water onto the wet SPE cartridge system with a constant flow rate was developed. The novel water vaporizing system, consisted of a vacuum pump, a water supply reserviour and tube and a mini space heater, could prevent the PAHs adsorption cartridge cracks occurred in the previous collector and effectively adsorb PAHs. The novel dry and wet deposition collector showed a good adsorption, desorption, and recovery rates of PAHs. By reducing the number of pumps used and employing polypyopylene (PP) instead of teflon as a material of collection funnel, the total construction costs were much reduced as compared with the previous dry and wet deposition collectors.

• International Journal of Highway Engineering
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• v.17 no.3
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• pp.27-33
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• 2015

PURPOSES : To ensure appropriate RCC properties with sufficient strength development and workability, it is necessary to secure a proper level of consistency. It is also necessary to secure maximum dry density, which is an important factor for increasing the interaction of aggregate interlocking, leading to an augmentation of RCC strength. On the other hand, the dry density of RCC can be changed owing to the compaction conditions, water content, and particle size distribution. A Proctor test and a modified Proctor test were used for determining the optimum water content needed to achieve maximum dry density with different amounts of compaction energy. A Vebe test, on the other hand, was used for checking the level of consistency, which is important for producing a workable mixture. METHODS : To confirm the degree of compaction at various particle sizes, RCC mixtures with different sand/aggregate ratios were evaluated. The Proctor test and modified Proctor test were applied to these mixtures to check the effect of the aggregate gradation and compaction energy on the maximum dry density and optimum water content. During each test, three specimens were produced for all types of water content under each aggregate gradation. A compaction curve and the optimum water content and maximum dry density for each aggregate gradation were then obtained for both tests. The range of water content for the appropriate consistency of each aggregate gradation was determined through a Vebe test. The optimum water content was then evaluated based on this range. RESULTS : The compaction test results show that the modified Proctor test provides a higher maximum dry density and lower optimum water content compared with the standard Proctor test. For the modified Proctor test, two cases of aggregate gradation (s/a = 30% and 70%) had the optimum water contents outside of the appropriate water content range. For the standard Proctor test, on the other hand, none of aggregate gradations provided the optimum water content within the desired range. CONCLUSIONS : The modified Proctor test should be used for an RCC mixture design because it can provide adequacy between maximum dry density and consistency. Moreover, the compaction roller has become highly developed for higher compaction energy.

• Food Science and Preservation
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• v.4 no.1
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• pp.33-38
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• 1997

In order to provide informations for designing packaging and storage condition of dry jujube (Zizyphus jujuba MILLER), moisture sorption isotherm was determined for temperatures of 20, 30 and 4$0^{\circ}C$, and quality changes were evaluated as function of temperature and water activity. Dry jujube at a given water activity showed higher equilibrium moisture content for lower temperature. Moisture isothem could be fitted by GAB model equation, giving higher C value, lower m0 and relatively constant k value with increase in temperature. Ascorbic acid was lost more highly at higher temperature and water activity, and showed negligible retention for whole range of water activity and temperature studied after 141 days. Browning increased with water activity up to 0.73 at 30 and 4$0^{\circ}C$. Dry jujube of high water activity had high L value in surface color, which represent brightness of surface color. Considering quality retention in the storage, dry jujube is desired to be dried to water activity of 0.42 and be stored at temperature below 3$0^{\circ}C$

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.4
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• pp.59-63
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• 2008

Purpose: The purpose of this study is to understand a relation of water content measurement with two different method, water removal method and dry method. Methods: 72 hydrogel contact lens containing various water content (ranged from 47% to 58%) were measured by the gravimetric method at 20$^{\circ}C$and 21% of the humidity. We weighed the dried test specimen at room temperature for 30 min after cooling. Results: In dry blotting method, the water content was measured to 47.43${\pm}$8.48%. The water contents was measured to 48.15${\pm}$8.36% with wet blotting condition. It was found that wet blotting method showed the higher water content of about 7% than dry blotting method. In water content with two dry methods, each of results was measured by 47.89${\pm}$8.06% and 49.56${\pm}$7.06%. In case of microwave method, the water content was measured significantly higher water content of about 1.67% than vacuum oven method. However, no statistical difference was found (p>0.05). Conclusions: In water removal method (Dry blotting method and Wet blotting method) to weigh hydrated test specimen, wet blotting method showed significantly higher water content than dry blotting method. Also in case of dry methods (vacuum oven and microwave) to weigh dry test specimen, water content of microwave method showed higher water content than vacuum oven method, but it should be noted that microwave oven method must be used carefully to measure accurateness on the specimen position and wave power.

• Journal of Ginseng Research
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• v.24 no.1
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• pp.23-28
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• 2000

To develop a dry alcohol containing red ginseng extract, dry alcohols composed of ethanol, water, dextrin and sodium lauryl sulfate were prepared using spray dryer, and their ethanol contents and encapsulation efficiencies were determined. An optimal dry alcohol containing red ginseng extract was chosen and the feeling for its oral administration was evaluated. Dextrin at dextrin/water weight ratios below 1.6/l and ethanol at ethanol/water weight ratios below 1/1 remarkably Increased both the ethanol contents and encapsulation efficiencies of dry alcohols. However dextrin at dextrin/water weight ratios above 1.6/1 and ethanol at ethanol/water weight ratios above 1/1 slightly decreased the both parameters. It might be due to the low solubility of dextrin in ethanol and limited diffusion coefficient of ethanol to the dextrin shell. furthermore, 0.5% (w/w) sodium lauryl sulfate gave the maximum ethanol content of dry alcohol. The more increased amounts of red ginseng extract were added, the more increased amounts of ginsenoside Rb1 but the more decreased amounts of ethanol were encapsulated in dry alcohols. A dry alcohol containing red ginseng extract was prepared with dextrin/ethanol/water (1/1/1, w/w/w) mixed solution, in which 0.5% (w/w) sodium lauryl sulfate and 20% (w/w) red ginseng extract were dissolved. It contained the ethanol contents of31.17$\pm$ 1.33% (w/w) and ginsenoside Rbl of 243.0$\pm$7.0 $\mu$g/g. It gave the moderate taste of red ginseng extract at Its oral administration with or without water Thus, the dry alcohol containing red ginseng extract can be further developed as a more convenient dosage form for red ginseng extract.

• Journal of Aquaculture
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• v.15 no.1
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• pp.49-60
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• 2002

Research on practices for improving water quality in channel catfish Ictalurus punctatus ponds was conducted at the Auburn University Fisheries Research Station, Auburn, Alabama, in 1998 and 1999. The objective of this two-year study was to determine better management practices to enhance water quality and improve production efficiency. In the first year, oxidation of bottom soil by drying, tilling, and applying sodium nitrate was performed (dry-till and dry-till with sodium nitrate treatments). The second year, based on the results obtained during the first year, precipitation of phosphorus (P) from water by applying gypsum was compared to the dry-till treatment (dry-till and dry-till with gypsum treatments). Control ponds were not subjected to bottom drying, tilling, sodium nitrate, or gypsum treatment. Channel catfish fingerings were stocked at 15,000/ha. In the first year, water in ponds from dry-till and dry-till with sodium nitrate treatments had lower concentrations (P < 0.01) of soluble reactive P, nitrate ($NO_{3} ^{-}) and nitrite ($NO_{2} ^{-}) nitrogen (N), total ammonia ($NH_3$) nitrogen, total suspended solids and turbidity, and higher values of pH, Secchi disk visibility, total alkalinity, total hardness, and calcium ($Ca^{2+}) hardness than water in control ponds. Ponds of the dry-till treatment also had lower concentrations (P < 0.01) of total P and total N than control ponds. Total fish production and survival rate did not differ among the treatments (P > 0.05). The findings suggested that drying and tiling pond bosoms between crops could achieve water quality improvement. Applying sodium nitrate to dry, tilled pond bosoms did not provide water quality improvement. In the second year, the treatment with the best results from the first year, dry-till, was compared with a dry-till with gypsum treatment. Enough gypsum was applied to give a total hardness of about 200 mg/L, and gypsum was reapplied as needed to maintain the hardness. Compared to the control, dry-till and dry-till with gypsum treatments had lower concentrations (P < 0.01) of total and soluble reactive P, total N, and total $NH_3$-N, and higher concentrations (P < 0.01) of dissolved oxygen. Ponds of the duty-till with gypsum treatment also had lower concentrations (P < 0.01) of chlorophyll $\alpha$, chemical oxygen demand, and total alkalinity than the control. Total fish production and survival rate did not differ (P > 0.05) among the treatments. These findings suggest that drying and tilling pond bosoms between crops and treating low hardness waters with gypsum could achieve water Quality improvement.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.1
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• pp.39-48
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• 2005

Nitrogen and sulfur deposition was measured on Lake Pal dang from March 2002 to October 2003. Wet and dry depositions were separately measured using wet- and dry-only samplers, respectively. In order to measure the dry deposition to the water body, a dry deposition sampler composed of three pans filled with pure water, called the deposition water, was used. Since ammonium was generally in excess in ambient air, more than half of ammonium was present in the gaseous form. Ammonium concentration was also generally higher than the sum of major anion concentrations in the deposition water because gaseous species were much easily deposited than the species in fine particles. Nevertheless, the contribution of gaseous ammonia to the deposition of ammonium was not high as well as that of particulate ammonium while the contribution of gaseous nitric acid was much higher than that of particulate nitrate. Annual wet deposition fluxes of nitrogen and sulfur were five and six times higher than their dry deposition fluxes, respectively. Except for ammonium, the dry deposition flux estimated in the present work was a half of the previous results. This was mainly caused by much smaller dry deposition velocities over the water than over the ground.