• 한국임상수의학회지
• /
• 제14권1호
• /
• pp.56-64
• /
• 1997

These studies were performed to investigate the complications affecting the vision after extracapsular lens extraction(ECE), the effects of an I/A (irrigation & aspiration)device and a viscoelastic material used on the vision, the occurrence of complications and the effective corneal incision method to reduce the corneal opacity in dogs. ECE was performed bilaterally with 3 different methods using clinically normal twele mixed dogs; the method in which I/A device and viscoelastic material were not used, the method in which I/A device was used but viscoelastic material not, and the method in which I/A device and viscoelastic material were used. Postoperative complications were observed as followed; conjunctival injection, uveitis, corneal opacity due to endothelial cell loss, hyphemia, remnants of lens cortex, vitreous loss, synechia and capsular opacity. Preservation rate of vision was lower significantly in the cases showing signs of synechia, capsular opacity, or remnants of lens cortex than the cases not showing the above signs(p<0.01). There were significant reduction of the complications such as corneal opacity, clot in anterior chamber in the group using I/A device compared to the group in which I/A device was not used(p<0.01). Groups using I/A device showed slightly higher vision than the group not using I/A device (75%; 42%). There were no significant differences in the occurrence rate of complications and the preservative rate of vision between the groups with and without viscoelastic material. The present study indicated that the postoperative complications of posterior synechia, capsular opacity, uveitis and vistreous loss were important factors affecting the vision and that I/A device was applicable to extract the lens cortex and effective to elevate the success rate after ECE in dogs.

• 한국작물학회지
• /
• 제45권4호
• /
• pp.241-244
• /
• 2000

This experiment was conducted to evaluate the effect on evapotranspiration and yield of soybean according to different soil water conditions, and to find the optimum time and amount for irrigation in soybean cultivation. The difference between potential evapotranspiration (PET) and maximum evapotranspiration (MET) during growing season of soybean planted in lysimeter was higher during reproductive stage than during vegetative one. The maximum crop coefficient was obtained at beginning seed stage of soybean. Soil water coefficient of irrigation treatment was higher than that of non-irrigation treatment during soybean growth stage in field experiment. Grain yield was highest in lysimeter due to its high water use efficiency and evapotranspiration rate.

• Journal of Advanced Marine Engineering and Technology
• /
• 제18권1호
• /
• pp.73-80
• /
• 1994

The water ejector is a low pressure high flow rate volumetric pump. It utilize the energy of a low mass flow, high velocity stream to induce a large mass flow, low velocity stream. In addition, it has a very good resistances to cavitation compared to the other type of pumps, and the maintenance cost is practically nil. There has been enormous energy loss to supply the upper part water of dam which has large potential energy as mere irrigation water in domestic multipurpose dam. The new type of energy saving system which developed through the present study can economizes over 950,000 kWh per year by mixing the upper part water of dam with the waste water by the large water ejector. This paper estimates the economical efficiency of the new type of irrigation water pumping system, and further more, represents the change of performance characteristics of large water ejector, which was adapted to this system, according to the fluctuation of upper water level that seasonally changes.

• 한국농공학회지
• /
• 제41권2호
• /
• pp.44-54
• /
• 1999

Agricultural water quality standards were reviewed through rice culture using treated sewage irrigation . The seqage from school building of Konkuk University was treated by a constructed wetland system, and theeffluent of the systeml was irrigated for rice culutre after nutrient concentration adjusted by dilution. Average concentration of COD, SS, T-N and T-P in irrigated water was 22.3mg/$\ell$, 6.5mg/$\ell$, 25.8 mg/$\ell$and 2.2mg/$\ell$, respectively. Treatment include irrigation of adjusted effluent with conventional fertilization (TWCF), adjusted effluent with no fertilization (TWNF). and effluent of the wetland system as it was with no fertilization (SWNF). These treatment plots were compared with control plot irrigated by tap water with conventional fertilization (CONTROL). Other environmentals for rice culture were identical for all the plots. Among them, TWCF showed the best growth rate and the highest yield, and constituents in the harvested rice showed not much difference among them. Which implies that irrigation with relatively high nutrient concentration compared to the current water quality standards may cause no adverse effect on rice culture and could be even beneficial . Although T-N for this study was 25 times greater than the current standards, rice culture wasnot adversely affected by irrigatino water quality and even beeter results were observed than the CONTROL. It could be mistakenly that clean irrigation water produces better agricultural product, however, it is not necessarily true. Irrigation water with moderate nutrient concentration can enhance the plant growth, and better result might be expected. Therefore, peer review and modification if necessary are needed to the current agricultural water quality standards, especially for the nutrient components.

• 한국환경생태학회지
• /
• 제29권6호
• /
• pp.947-951
• /
• 2015

본 연구는 옥상녹화를 비롯한 인공지반녹화에 활용 가능한 조경용 초화류의 원활한 생육을 위한 적정 관수 주기를 규명하고 옥상 조건에서 관수 필요 여부를 규명하고자 하였다. 옥상녹화에 적용 가능하며 관상가치가 있는 총 20종의 초본식물을 선정하여 녹화용 식물의 토양수분흡수특성을 알아보기 위한 시험과 관수주기에 따른 식물의 생육변화를 알아보기 위한 시험으로 나누어 시행하였다. 식물의 수분스트레스와 열스트레스를 최소화하기 위해서는 평균 4~5일 이전의 관수 주기가 요구되며 식물의 원활한 생장과 이에 따른 환경적 효과를 위해서는 반드시 관수 관리가 요구된다고 판단되었다. 이러한 결과는 건축물이나 인공지반 녹화 시 기초자료로 활용하여 지속가능한 식재계획 수립에 도움이 될 것으로 기대되며, 향후 좀 더 다양한 녹화식물들에 대한 연구가 필요할 것으로 생각된다.

• 농업과학연구
• /
• 제47권4호
• /
• pp.1057-1069
• /
• 2020

For most upland crops in Korea, underground water is used to ensure an adequate water supply. Thus, surface water storage tanks are needed to supply surface water from reservoirs or streams. This study discusses the design, manufacture and monitoring of a water storage tank capable of reliably supplying water to crops and preventing the inflow of floating debris. The study was conducted in an apple orchard in Yesan-gun, Chungcheongnam-do in Korea. Based on the water requirements of the crops and size of the orchard, a required flow volume of about 0.6 ㎥·h-1 was determined, along with a surface water storage tank capacity of 1.2 ㎥. Following a comparison with other materials, stainless steel (STS) was used to construct the water tank. The tank was designed to provide 14 hours of irrigation, enabling a small-capacity, cost-efficient tank design to be used. A surface water irrigation test was performed using the surface water storage tank. The average surface water irrigation flow rate was 0.00045 ㎥·m-2·h-1. The water quality test showed that the pH, suspended solids (SS), total nitrogen (TN), and total phosphorus (TP) values satisfied the reference values for agricultural water. The test results showed that the surface water storage tank evaluated in this study allows for crop irrigation when there is a lack of groundwater during droughts.

• 한국유기농업학회지
• /
• 제25권2호
• /
• pp.311-328
• /
• 2017

두둑과 고랑을 재활용한 한국형 무경운 농업에서 유기물 투입과 관수 효과를 구명하고자 무경운 토양에서 시험을 수행하였다. 1. 토양 미생물상 1회 전량관수 조건에서 대두박 투입 처리구의 토양 세균과 곰팡이 수는 대두박 무 투입구에 비하여 많았다. 그리고 유기질비료 투입량이 표준시비량 66%까지 증가되면 세균과 곰팡이 수는 증가되었으나, 그 이상에서는 세균과 곰팡이 수가 감소되는 경향이었다. 곰팡이/세균 비율은 관수 방법과 관계없이 대두박 투입 처리에서 0.6과 1.1로, 무투입 처리의 0.2와 0.5보다 2배 이상 높았다. 1회 전량 관수 조건에서 유기질 비료 시비량이 증가되면 대두박을 투입한 처리는 방선균 수는 감소되는 경향이었으나, 대두박 무투입에서는 증가되었다. 2회 분할 관수는 1회 전량관수에 비하여 대두박 무 투입 조건에서 세균과 곰팡이 수가 증가되었으나, 대두박 투입조건에서는 방선균 수가 증가되었다. 2. 토양 효소 유기질 비료의 시비량이 증가되면 토양 내 Chitinase 활성은 대두박 투입 토양에서 감소되고, 대두박 무 투입에서는 증가되는 경향이었다. 그러나 대두박을 투입에 관계없이 2회 분할 관수는 1회 전량관수에 비하여 Chitinase 활성이 증가되었다. 1회 전량관수 조건에서 대두박 투입 처리구의 ${\beta}$-Glucosidase 활성은 무투입에 비하여 높았으며, 유기질 비료 투입량이 증가되면 표준시비량의 66%까지는 ${\beta}$-Glucosidase 활성이 증가되었으나, 표준시비량에서는 감소되었다. 대두박 무투입 조건에서 2회 분할관수 토양 내 ${\beta}$-Glucosidase 활성은 1회 전량관수에 비하여 현저하게 증가되었다. 1회 전량관수 조건에서 대두박을 투입한 처리의 N-acetyl-${\beta}$-D-glucosaminidase의 활성은 무투입구에 비하여 높았다. 대두박 투입 처리에서 유기질 비료 투입량이 표준시비량의 66%까지 증가되면 N-acetyl-${\beta}$-D-glucosaminidase의 활성은 증가되었으나, 표준시비량에서는 유의적인 차이가 없었다. 대두박 무투입 조건에서 2회 분할관수는 1회 전량관수에 비하여 N-acetyl-${\beta}$-D-glucosaminidase의 활성은 증가되었다. 대두박 무투입 조건에서 유기질 비료 시비량이 표준량의 66% 수준에서는 토양 내 산성인산가수분해효소(Acid phosphatase)의 활성 높았다. 대두박 투입 조건에서는 유기질 비료 시비량이 증가되면 산성인산가수분해효소(Acid phosphatase)의 활성은 증가되는 경향이었다. 3. 토양 AMF 대두박 무투입 조건에서 유기질 비료의 투입량이 표준시비량의 66%까지 증가되면 토양의 내생균근균의(AMF) 포자수는 증가되었으나, 유기질 비료 투입량이 표준시비량에서는 근균의 포자수는 감소되었다. 그러나 대두박 투입에서 근균의 포자수는 유기질 비료 투입량에 따른 유의적인 차이가 없었다. 그리고 내생 근균의 고추 뿌리에 정착률은 대두박 투입량에 따른 유의적인 차이가 없었으며, 2회 분할 관수도 같은 경향이었다.

• 한국농공학회논문집
• /
• 제48권3호
• /
• pp.97-106
• /
• 2006

The pollutant concentrations at experimental paddy plots with three (excessive, standard, reduced) different fertilization rates were investigated during 2001-2002 irrigation seasons. Mean concentrations of pollutants in ponded water were not significantly different among three experimental plots, but the T-N concentrations in percolated water significantly depended on fertilization rates. The T-N, T-P and $COD_{Cr}$, concentrations in ponded water during early irrigation season (late May to mid-June) were much higher than those during later irrigation season likely due to fertilization and low uptake by young rice crops. The T-N concentrations decreased but the concentrations of T-P and $COD_{Cr}$, increased three days after tillering fertilization. The removal rates of T-N by paddy plots were $0.13-0.16g/m^2{\cdot}d$ for an excessive fertilization plot, $0.08-0.25g/m^2{\cdot}d$ for a standard fertilization plot, and $0.03-0.34g/m^2{\cdot}d$ for a reduced fertilization plot three days after tillering fertilization. On the other hand, T-P and $COD_{Cr}$, were released three days after tillering fertilization.

• 한국작물학회지
• /
• 제60권4호
• /
• pp.431-435
• /
• 2015

Rice (Oryza sativa L.) ratooning is the production of a second rice crop from the stubble left behind after the main crop harvest. The objectives of this study were to evaluate the effects of main-crop stubble height, irrigation and fertilization on ratoon grain yield. Main crop 'Jinbuol' rice cultivar was harvested to leave with 10, 20, 30, or 40 cm stubble height. When the main crop stubble was harvested with 10 cm height, ratoon rice grain yield was increased by 2,810 kg/ha. Irrigation on stubbles after main crop harvest did not affect the ratoon crop yield and rice quality. The results showed a large variation in the ratoon performance by fertilizer application methods. Top-dressed nitrogen fertilizer on the stubble after harvest caused increase in panicle production and higher maturity rate. However, there was no significant difference in protein content, amylose content of milled rice and cooked rice characters between plots managed with and without nitrogen fertilizer.

• Restorative Dentistry and Endodontics
• /
• 제47권1호
• /
• pp.11.1-11.11
• /
• 2022

This study aimed to describe the outcomes of the GentleWave system (GW) (Sonendo) on root canal treatment. Published articles were collected from scientific databases (MEDLINE/PubMed platform, Web of Science, Scopus, Science Direct and Embase). A total of 24 studies were collected from August/2014 to July/2021, 20 in vitro and 4 clinical. GW System was not associated with extrusion of the irrigant, promoted faster organic dissolution than conventional syringe irrigation (CSI), passive ultrasonic irrigation (PUI) continuous ultrasonic irrigation (CUI) and EndoVac, reduced more bacterial DNA and biofilm than PUI and CUI, promoted higher penetration of sodium hypochlorite into dentinal tubules than PUI and CUI in vitro, and removed more intracanal medication than CSI and PUI. GW was able to remove pulp tissue and calcifications. Moreover, its ability to remove hard-tissue debris and smear layer was better than that of CSI, and its ability to remove root canal obturation residues was lower or similar to that of PUI, and similar to that of CSI and EndoVac. Regarding root canal obturation of minimally instrumented molar canals, GW was associated with high-quality obturation. Clinically, the success rate of endodontic treatment using GW was 97.3%, and the short-term postoperative pain in the GW group was not different from CSI. Further research, mainly clinical, is needed to establish whether GW has any advantages over other available irrigation methods.