• 한국물환경학회지
• /
• 제22권4호
• /
• pp.619-625
• /
• 2006

Amount of soil loss is important information for the proper water quality management, In this research, annual average soil loss of the Geum River basin was estimated using RUSLE (Revised Universal Soil Loss Equation) and GIS (Geographic Information System). Input data were manipulated using ArcGIS ver. 8.3. From crop field which constitute 8.2% of the Geum River Basin, annual average soil loss was estimated as 53.6 ton/ha/year. From the rice paddy field which constitutes 20% of the Geum River Basin, soil loss was estimated as 33.5 ton/ha/year, In comparison, forestry area which constitutes 61.8% of the basin discharged 2.8 ton/ha/year, It could be known from this research that appropriate measures should be implemented to prevent excessive soil loss from the agricultural areas.

• 한국농공학회논문집
• /
• 제56권6호
• /
• pp.159-167
• /
• 2014

In this study the process of normalizing hydraulic head loss rate was developed for the purpose of estimation of seepage blocking state at each seepage segment in sea dike embankment. Pore water pressure sensors were installed with some interval along seepage path, then the hydraulic head loss rate at each segment between pore water pressure sensors was calculated, and then the calculated hydraulic head loss rate was normalized based on seepage path length. The comparison of normalized hydraulic head loss rates showed that the cross section of sea dike embankment was homogeneous approximately and the width of cross section was long enough to blocking tide water.

• 한국재료학회지
• /
• 제32권3호
• /
• pp.146-152
• /
• 2022

One disadvantage of deep cycle flooded lead-acid batteries is increasing water loss caused by use of (+) Pb-Sb / (-) Pb-Sb alloy grid. Water loss is generated by the emission of hydrogen gas from the (-) electrode during battery charging. In this paper, we maintain cycle life aspect through the development of hybrid flooded lead-acid batteries to which a (+) Pb-Sb / (-) Pb-Ca grid is applied and deal with the improvement of water loss. The amount of water loss compared to that of the (-) Pb-Sb grid decreased when Ca was added to the (-) Pb grid. For the (-) Pb-Ca grid, it was confirmed that the time to reach 0.0 V, at which water decomposition occurs, was increased compared to that of the (-) Pb-Sb grid at the NPV (Negative Potential Voltage). In the cycle life test conducted with the BCI (Battery Council International) standard, compared to the (+) Pb-Ca grid, the (+) Pb-Sb grid increased the life cycle of the batteries and the (+) Pb-Ca grid showed an early end of life due to PbO corrosion layer generation, as determined through SEM / EDS and Tear Down analysis. In conclusion, by addition of Sb to (+) Pb grid and Ca to (-) Pb grid, we developed a hybrid flooded lead-acid battery that meets user requirements to improve water loss characteristics and preserve cycle life characteristics.

• 수산해양기술연구
• /
• 제18권1호
• /
• pp.17-23
• /
• 1982

한국국적의 유조선 35척의 외판 및 격벽의 부식도를 선령별로 조사한 결과를 요약하면 다음과 같다. 1. 선령 12년급의 외판의 평균부식도는 경흘수선 및 하부 만곡부선에서는 선수부가, 건현 및 상부만곡부선에서는 중앙부가, 양재흘수선에서는 선미부가 가장 높다. 2. 선령 20년급의 외판의 평균부식도는 경흘수선 및 상.하부만곡부선에서는 선수부가, 건현중앙선에서는 중앙부가, 만재 흘수선에서는 선미부가 가장 높다. 3. 측수조와 중앙유조의 횡격벽의 평균부식도는 어느 선령에서나 정부선, 상부선, 중앙선에서는 측수조가 높고, 하부선과 저부선에서는 중앙유조가 높다. 4. 중앙유조와 양측 유조의 횡격벽부식도 어느 선령에서나 중앙유조의 횡격벽 쪽이 높다. 5. 중앙유조의 종.횡격벽의 부식도는 격벽의 중앙선상부에서는 어느 선령에서나 종벽부 쪽이 높다. 6. 내부수조 및 중앙유조의 횡격벽과 같은 높이에 있는 선각외판의 건현부의 평균부식도를 비교하면, 격벽상부의 부식도가 외판의 그것보다 크다.

• 한국식품영양과학회지
• /
• 제27권5호
• /
• pp.881-889
• /
• 1998

For the application of the commercially modified starch in frozen and retort foods, apparent viscosity and water loss were measured at each stages of heating, sterilization and freezing-thawing stages. Apparent viscosity showed the exponential increase with concentration and the slopes of apparent viscosity against concentration in the Firm-Tex(hydroxypropyl distarch phosphate), Hi-Flo(acetylated distarch adipate) and Colflo 67(acetylated distarch adipate) from waxy maize starch were higher than those of Amyloacetate M20(starch acetate) and X-amylo 250(distarch phosphare) from potato starch. In the presence of 1 or 2% NaCl, X-amylo 250 among modified starches showed the increase in water loss and the decrease in apparent viscosity, whereas Colflo 67, Hi-Flo and Firm-Tex were little affected by NaCl. In the presence of 1 or 2% sucrose, water loss and apparent viscosity of the modified starches were not affected. In the range of pH 4~8, water loss and apparent viscosity of the modified starches had no change but the differences were detected to some extent between each of heating, sterilization and freezing-thawing stages. In the apparent viscosity and water loss of the modified starches after 3 week storage from heating and sterilization, Hi-Flo, Amyloacetate M20 and X-amylo 250 were not changed at the storage period, and the overall acceptability of retort food containing the modified starches such as Firm-Tex and Amyloacetate M20 were favored more than others. In the apparent viscosity and water loss of the modified starches which have been frozen and thawed three times repeatedly, Colflo 67, Hi-Flo and Firm-Tex were not changed in freezingthawing, and the overall acceptability of frozen food containing Firm-Tex was most favored.

• 대한기계학회논문집A
• /
• 제27권3호
• /
• pp.363-371
• /
• 2003

This study is mainly concerned with phenomenon of cavitation-erosion on the several materials and corrosive liquids which were applied with vibrator(suggested by ASTM G 32, 20KHz, 50$mu extrm{m}$). The maximum erosion rate by cavitation erosion in both of distilled water and sea water appeared to be proportioned to their hardness and tensile strength. Cavitation weight loss and rate of cast iron in sea water condition were greater(approximately 3 times) than that in distilled water condition, however in case of stainless steel and brass the cavitation weight loss of composite materials were not so different in both of their conditions. Cavitation weight loss of composite materials were shown as below on this test, Duratough DL : Weight loss in sea-water condition were greater (approximately 2.3 times) than it's distilled water condition. The main tendency of cavitation erosion for metals appeared that small damaged holes causing by cavitation erosion was observed with radial pattern. On the other hand, the tendency for composites appeared that small damaged holes were observed randomly.

• 한국복합재료학회:학술대회논문집
• /
• 한국복합재료학회 1999년도 추계학술발표대회 논문집
• /
• pp.227-233
• /
• 1999

This study is mainly concerned with phenomenon of cavitation-erosion on the several materials and corrosive liquids which were applied with vibrator (suggested by ASTM G-32, 20KHZ, 24{$mu}m$).The main results obtained are summarized as follows ; (1) The maximum erosion rate by cavitation erosion in both of fresh-water and sea-water appeared to be proportioned to their hardness and tensile strength. (2) Cavitation weight loss and rate of cast iron in sea-water condition were greater (approximately 3 times) than that in distilled-water condition, however in case of stainless and brass the cavitation weight loss and their rates were not so different in both of their conditions. (3) Cavitation weight loss of composite materials were shown as below on this test, DuraTough DL : Weight loss in sea-water condition were greater (approximately 2.3 times) than it's fresh-water condition. (4) As the result of observation with digital camea of specimens, the main tendency of cavitation erosion for metals, was that small damaged holes causing by cavitation e개sion was appeared with radial pattern, and composites materials was that small damaged holes were appeared randomly.

• Journal of Electrochemical Science and Technology
• /
• 제10권4호
• /
• pp.381-386
• /
• 2019

Zn-air battery uses oxygen from the air, and hence, air holes in it are kept open for cell operation. Therefore, loss of water by evaporation through the holes is inevitable. When the water is depleted, the battery ceases to operate. There are two water consumption routes in Zn-air batteries, namely, active path (electrolysis) and passive path (evaporation and corrosion). Water loss by the active path (electrolysis) is much faster than that by the passive path during the early stage of the cycles. The mass change by the active path slows after 10 h. In contrast, the passive path is largely constant, becoming the main mass loss path after 10 h. The active path contributes to two-thirds of the electrolyte consumption in 24 h of cell operation in 4.0 M KOH. Although water is an important component for the cell, water vapor does not influence the cell operation unless the water is nearly depleted. However, high oxygen concentration favors the discharge reaction at the cathode.

• Journal of Pharmaceutical Investigation
• /
• 제25권2호
• /
• pp.95-100
• /
• 1995

Serum electrolyte concentration and body weight were determined before and after exercise for 2h in Korean cyclists. The serum concentration of electrolytes (Na, Ca, Zn, K, P and Cl) was increased but that of Mg was decreased as a result of exercise. The increase of serum K and P concentration was statistically significant after exercise. As the exercise time increased, the loss of body weight also increased due to dehydration and sweat. The loss of body weight ranged 1.0 to 2.3 Kg as a function of exercise time but cyclists showed the exhaustion and muscle fatigue 2h after exercise. As the ambient temperature increased, the loss of body weight was slightly increased. However, frequent drinking water was required because of dehydration and thirst. Although frequent drinking water may reduce weight loss and thirst during exercise, sports drinking beverages simultaneously containing electrolytes and nutrients are more useful to replenish loss of water and electrolytes in an exhausted condition, resulting in the improvement of physical performance.

• 한국염색가공학회:학술대회논문집
• /
• 한국염색가공학회 2012년도 제46차 학술발표회
• /
• pp.88-88
• /
• 2012

Applied decanol and nonanol provided more weight loss than applied heptanol and octanol. PET using decanol showed the highest weight loss than other alcohols applied. Sodium hydroxide caused weight loss in PET fabrics because terephthalic acid and ethylene glycol were separated by the hydrolysis of the ester group in the PET chains. The terephthalic acid was neutralized to disodium terephthalate and the reaction results in weight loss in the PET fabrics. The weight loss increased with increasing hydrolysis time because disodium terepthalate was water soluble and the reaction was not reached at equilibrium. Pretreatment alcohols increased water absorption, especially in case of PET applied decanol revealed the highest water absorption. PET applied decanol showed 400% of initial water absorption, and PET applied nonanol revealed 250% of initial water absorption. However, the pristine PET showed 90% initial water absorption, and it revealed 230% maximum water absorption as compared to other alcohols. Also, PET applied decanol, nonanol, octanol and heptanol showed 600%, 400%, 350% and 300% maximum water absorption, respectively. The result implied alcohol length affected on water absorption of PET fibrous assembly. This implies that the microvoid of the PET surface hold water molecules. Surface morphology of PET appears that the pretreatment reagent attacks almost entire surface of the fiber, causing surface etching. As the surface etching progresses, it propagates inside the fiber, resulting in the formation of elongated cavities on the surface.