• 대한영양사협회학술지
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• 제18권1호
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• pp.16-29
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• 2012

The purpose of this study was to investigate the changes in nutritional status of gastrectomy patients. The anthropometric and biochemical data were measured at pre-operation, at discharge, 1 month after discharge, and 3 months after discharge. Nutrient intake levels, nutrients adequacy ratio (NAR), mean adequacy ratio (MAR), and the proportion of patients with intake levels inferior to those of dietary reference intakes (DRIs) were analyzed at discharge, 1 month after discharge, and 3 months after discharge. Finally, the data on 23 patients (15 male and 8 female) were collected and used for statistical analysis. Fifteen patients underwent subtotal gastrectomy, and 8 patients underwent total gastrectomy. Compared to pre-operation, body weight and body mass index of subjects significantly decreased at discharge, 1 month after discharge, and 3 months after discharge (P<0.001). Serum albumin (P<0.001), total lympocyte count (P<0.001), total cholesterol (P<0.001), hemoglobin (P<0.001), hematocrit (P<0.001), and mean corpuscular hemoglobin concentration (P<0.05) were significantly different between pre-operation, at discharge, 1 month after discharge, and 3 months after discharge. The proportions of patients with lower nutrient intake levels than DRIs were substantial. MAR at discharge, 1 month after discharge, and 3 months after discharge were 0.70, 0.80 and 0.91, respectively. Especially, the NARs of folate, niacin, vitamin $B_2$, vitamin C, and zinc were all low. Considering the various nutritional problems of gastrectomy patients, systematic medical nutrition therapy is needed after gastrectomy.

• 한국토양비료학회지
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• 제48권6호
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• pp.671-676
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• 2015

Control of surface runoff from upland soil is essential to reduce nonpoint source pollution. The use of non-woven fabric as a soil cover can be helpful to control surface runoff. The field experiment was conducted to evaluate the furrow cover effects of black non-woven fabric on the nutrient discharge from upland soil used for red pepper cultivation. The experimental plots consisted of chemical fertilizer (CF), cow manure compost (CMC), and pig manure compost (PMC) treatment. Each nutrient material treatment plot has control (no furrow cover (NFC)) and black non-woven fabric cover treatment, respectively. The amount of nutrient application was chemical fertilizer of $190-112-149(N-P_2O_5-K_2O)kgha^{-1}$, cow manure compost of $29.5tonha^{-1}$, and pig manure compost of $7.9tonha^{-1}$ as recommended amount after soil test for red pepper cultivation. Compared to control (NFC), furrow cover treatment with black non-woven fabric reduced the amount of T-N discharge by 50% at CF treatment, 36.9% at CMC treatment, and 44.8% at PMC treatment. Furrow cover treatment with black non-woven fabric reduced the amount of T-P discharge by 37.1% at CF treatment, 49.9% at CMC treatment, and 63.4% at PMC treatment compared to control (NFC). The production of red pepper did not show significant difference. There was no weed occurring in furrow cover treatment plots with black non-woven fabric. Results from this study showed that the furrow cover with black non-woven fabric could play a significant role in reduce nutrient discharge from upland soil used for red pepper cultivation.

• 생태와환경
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• 제44권4호
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• pp.337-346
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• 2011

We investigated nutrient loading and trophic states in a coastal estuarine system in the Asan estuary by assessing phytoplankton biomass and using the trophic index (TRIX). The monthly and yearly nutrient loading (TN, TP) from freshwater discharge from the Asan and Sapgyo reservoirs into the estuary were estimated and analyzed with related factors. Monitoring data (physio-chemical and biological variables) collected at five estuary stations were used to assess trophic states. Descriptive statistics of total phytoplankton cells, chl a concentrations and primary productivity were also used to assess seasonal trophic status. N loading from freshwater ranged $1.0{\sim}1.3{\times}10^4$ ton yearly. The yearly P loading ranged between 350 and 400 ton during 2004~2006, increasing to 570 ton in 2007. Regression results suggest that DIN and DSi were correlated with freshwater discharge at the upper region. Based on phytoplankton biomass and total cell abundance, the trophic state of the estuary was found to be eutrophic during spring due to phytoplankton bloom. Primary productivity level was remarkably high, especially in summer coinciding with high nutrient loading. Pheopigments increased during warm seasons, i.e. summer and fall. Trophic index results indicate that the trophic state varied between mesotrophic and eutrophic in the estuary water body, especially in the upper region. The results suggest that phytoplankton production was regulated by nutrient loading from freshwater whereas biomass was affected by other properties than nutrient loading in the Asan Estuary ecosystem.

• Ocean and Polar Research
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• 제40권4호
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• pp.191-202
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• 2018

In this study we conducted a weekly monitoring exercise at a fixed station in the saltwater zone during the dry season (Jan-Mar, 2013) and wet season (Jun-Aug, 2013) to understand the fluctuations in phytoplankton communities and environmental factors in the Youngsan River estuary altered by a dike constructed in the coastal area. Phytoplankton communities displayed seasonality; diatoms were dominant during the dry season whereas dinoflagellates were dominant during the wet season. T-test analysis showed that water temperature was significantly different between the seasons whereas freshwater discharge from the dike was not significantly different. This suggests that seasonal variations of phytoplankton are more likely affected by water temperature than freshwater discharge. However, a short-term fluctuation was also observed in response to freshwater discharge; freshwater species appeared during or after the discharge in the dry and wet seasons and blooms of harmful species developed after the discharge. Phytoplankton communities may be affected by changes in physical factors such as turbidity and salinity and nutrient supply resulting from freshwater discharge. Especially, the nutrient supply may directly contribute to the harmful algal blooms (HABs) composed of dinoflagellates which can adapt to low salinity after freshwater discharge.

• 한국환경과학회지
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• 제23권6호
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• pp.1049-1060
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• 2014

We investigated the spatiotemporal variations of dissolved inorganic nutrients along a saline gradient to estimate nutrient fluxes in the Seomjin River estuary during dry (March 2005, March 2006, March 2007, and March 2008) and rainy seasons (August 2005, July 2006, July 2007, and July 2008). Dissolved inorganic nitrogen concentrations were similar in the endmembers of freshwater for the rainy and dry seasons. In contrast, the concentrations of dissolved inorganic phosphate and silicate in the rainy season were approximately 2-3 times higher than those in the dry season. River discharge was approximately 10 times higher in the rainy season ($212m^3sec^{-1}$) than in the dry season ($21m^3sec^{-1}$). The fluxes of dissolved inorganic nitrogen, phosphate, and silicate were 2.91, 0.004, and 2.51 tons $day^{-1}$ in the dry season and 7.45, 0.421, and 30.5 tons $day^{-1}$ in the rainy season, respectively. Although the range of nutrient concentrations were similar to previous results from investigations in the Seomjin River estuary, the nutrient fluxes were differed according to river discharge for different survey periods.

• Asian-Australasian Journal of Animal Sciences
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• 제12권7호
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• pp.1162-1169
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• 1999

Modern livestock production facilities face both challenges and opportunities with respect to sustainable manure management practices. Nutrient recycling is constrained by the size of modern livestock operations, the low nutrient density of liquid manures, and the spatial and temporal variability of manure nutrient concentrations. These constraints can and must be addressed or farmers will be increasingly drawn to nutrient wasting strategies such as anaerobic lagoons, wetlands, and other systems designed to treat and discharge nutrients to the environment. Intentional discharge of nutrients is difficult to justify in a sustainable agricultural production system, since replacing those nutrients through chemical fertilization requires considerable expenditure of energy. In contrast, there are several currently viable technologies which provide the homogenization and stabilization needed to successfully compete against chemical fertilizers, including composting, pelletization, and anaerobic digestion. Some of these technologies, particularly anaerobic digestion and composting, also open up increased opportunities to market the energy and nutrients in manure to non-agricultural uses. Future advances in biotechnology are likely to demonstrate additional options to transform manure into fuels, chemicals, and other non-agricultural products.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회 논문집
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• pp.1254-1258
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• 2005

Net outflow flux and unit load of pollutants were investigated at a paddy fields area(Soro-ri) with large-scaled plots on loam soil during irrigation seasons of $2001\~2003$. Water samples were collected, and inflow and outflow were .measured at $5\~10$ day intervals during non-storm periods and at $2\~6$ hours intervals during storm events. The average concentration of TP in percolated water was much smaller than that in irrigation and surface outflow water likely due to phosphorus absorption capacity of paddy soils. Net outflow flux in study area was significantly correlated with rainfall and surface outflow discharge. Nutrient flux from Paddy fields can be abated by reduction in outflow surface discharge.

• 유기물자원화
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• 제24권1호
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• pp.11-19
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• 2016

농경지에 작물재배를 위한 양분재료의 과다한 투여는 주변 수계로의 양분유출을 증가시킬 수 있다. 고추재배시 사용되는 양분재료는 화학비료, 우분퇴비, 돈분퇴비 등이 대표적이다. 볏짚은 벼 재배의 부산물로 밭 농사에서 잡초발생 억제, 토양수분 보존, 유기물 재료로 널리 사용된다. 본 연구는 노지 고추 재배에서 밭 고랑을 볏짚으로 피복할 때 강우로 발생하는 표면 유출수에 의한 양분유출 특성을 파악하기 위해 수행하였다. 시험구는 양분재료를 기준으로 하여 화학비료, 우분퇴비, 돈분퇴비로 구분하였고 양분투입량은 토양검정 시비량에 준하여 처리하였다. 각각의 시험구는 화학비료 또는 우분퇴비, 돈분퇴비를 시용한 후 볏짚으로 덮은 경우(피복 처리구)와 덮지 않은 경우(무피복구)로 구분하였다. 화학비료 처리구와 우분퇴비 처리구의 볏짚 고랑 피복 처리는 무피복구 보다 T-N (총질소)의 유출이 각각 $1.4kg\;ha^{-1}$, $2.1kg\;ha^{-1}$ 감소하였다. 반면에 화학비료 처리구와 우분퇴비 처리구, 돈분퇴비 처리구의 볏짚고랑 피복 처리는 무피복구 보다 T-P (총인)의 유출이 각각 $2.1kg\;ha^{-1}$, $2.1kg\;ha^{-1}$, $0.2kg\;ha^{-1}$ 증가하였다. 볏짚은 질소 0.4 %, 인산을 0.3 % 함유하고 있고 증류수에 볏짚을 담근 후 3주일 내에 인산 성분이 유출되므로 T-P의 유출은 고랑을 피복한 볏짚에서 기원한 것으로 추정된다. 무피복구에 비하여 고랑 볏짚 피복구는 잡초발생이 줄었다. 그러나 붉은 고추의 수확량은 무피복구와 볏짚피복구 간에 유의한 차이를 나타내지 않았다. 결론적으로, 고추밭 고랑을 볏짚으로 과다하게 피복하면 T-P의 유출을 유발할 수 있으므로 고랑을 피복하는데 적정한 볏짚량을 산정하기 위한 추가적인 연구가 필요하다고 판단되었다.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1997년도 동계 학술대회 논문집
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• pp.255-262
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• 1997

A low-cost and precise metering device, which is suitable to automatic mixing of nutrient-solution for hydroponic culture, was developed for small-scale growers. The metering device was composed of three parts those were supply pumps, metering cylinders and venturi tube. Those parts were controlled by personal computer with time-based odoff control method. To verify the performance of the developed metering device, the relationship between operating time and discharge was examined and the accuracy of the developed metering device was compared with commercial metering pumps. The results of this study are as follows. 1. The correlation coefficient between the flow rate and operating time was 0.9999, and the linear regression equation computed was y=21.759x, where y is the discharge(g) and x is the operating time(s). 2. The developed device has greater accuracy than commercial metering pumps in terms of the full-scale error. Calculated errors for the developed metering device and two commercial pump were $\pm$0.3 %, $\pm$2.45 % and $\pm$1.38 % respectively. 3. Above results show developed metering device is a useful tool for nutrient-solution control system.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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• pp.728-733
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• 2002

The measurement of river discharge is among the most fundamental observations and is necessary for understanding many water-related issues, such as flooding hazards, sediment transportation, and nutrient movement. Traditionally river discharge is estimated by measuring the water stage and converting the measurement to discharge using a stage-discharge rating curve. The possibility of monitoring river discharge from satellites has been largely ignored, because it is difficult to measure water surface information from space with sufficient precision. In this paper, an efficient approach to discharge estimation using mainly satellite data is developed and described. The proposed method, which focuses on the measurement of water-surface width coupled with river width-stage and stage-discharge relationships, is applied to the Yangtze River with good results.