• The Korean Journal of Ecology
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• 제23권2호
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• pp.157-161
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• 2000

Mass loss and changes of mineral nutrients during decomposition of Phragmites communis for 13 months from November 1998 to December 1999, were investigated at the fringe of stream at Boryeong, Chungnam Province in Korea. Plant materials, which were collected in November 1998. were divided into leaves, culms and rhizomes. Litterbags, 15${\times}$15 cm, were made of nylon mesh with 2-mm$^2$ holes. At 13 months after installation, remaining mass of leaves, culms and rhizomes was 29.0%, 57.4%, 20.6%, respectively. Mass loss rate of the culms was significantly lower than those of the leaves and rhizomes. The decay rate of leaves, culms and rhizomes was 1.21. 0.42 and 1.48 per year, respectively. Initial concentration of N, P, K, Ca and Mg of leaves. culms and rhizomes was 22.5, 9.0, 15.5 mg/g for N, 0.34. 0.10, 0.33 mg/g for P, 15.0, 12.5. 12.3 mg/g for K, 2.84. 0.80, 0.03 mg/g for Ca. 1.94. 0.97, 0.40 mg/g for Mg, respectively. Concentrations of nutrients were higher in leaves than in culms and rhizomes. Except for N and Mg in rhizomes, there was no immobilization period during the decomposition. In the case of remaining K and Ca, most are lost during the first 3 months. Without any suitable method for removal of dead part, eutrophication of freshwater may be accelerated by dead macrophytes.

• Journal of Applied Biological Chemistry
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• 제43권2호
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• pp.86-93
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• 2000

An experiment was conducted to obtain the quantitative data on the transformation and loss of applied urea-N in waterlogged soil columns. The soil columns were pre-incubated for 35 days to develop oxidized and reduced soil conditions prior to urea application. After urea application at the rate of $150kg\;N\;ha^{-1}$(29.5 mg N), the amounts of nitrogen which were volatilized, leached, and remained in soil column were measured during 38 days of incubation period. On 2 and 4 days of incubation, 54.1%(15.9 mg N) and 98.4%(29.0mg N) of the applied urea was hydrolyzed, respectively. Most of the applied urea was completely hydrolyzed within 6 days. After urea application, the rates of ammonia volatilization were increased with the floodwater pH when the floodwater pH were higher than 7.0. The maximum rate of ammonia volatilization was $0.3mg\;d^{-1}$ when pH of the floodwater showed maximum value of 7.6. The total amount of volatilized nitrogen was 6.1% (1.8mg N) of the applied urea-N. A 63.2 % (18.6mg N) of the applied urea was remained in soil as $NH_4{^+}-N$ and 28.0% (8.2mg N) of the applied urea was leached as $NH_4{^+}-N$ at the end of the incubation. Amount of $NO_3{^-}-N$ in soil was smaller than 2.0 mg throughout the incubation period. The total amount of $NO_3{^-}-N$ leached was very small, which value was 1.8 mg. It suggested that nitrification process was not significant in waterlogged soil column of this study due to high infiltration rate of urea solution applied to the soil column. Therefore only small amount of $NO_3{^-}-N$ was lost by denitrification and leaching process.

• 대한지리학회지
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• 제39권4호
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• pp.544-561
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• 2004

본 연구에서는 대관령 지역의 산림 및 농경지 소유역을 대상으로 주 1회의 유량 및 수질 조사를 실시하고 유량 및 수질 항목간의 상관관계를 분석하였다. 산림 소유역의 수질 변화는 적었던 반면 농경지 소유역에서는 화학비료 및 가축분 퇴비의 시용과 토양 유실로 인해 큰 폭의 수질 변화를 보였다. 용존산소량(DO)은 두 소유역에서 유량보다는 수온과 매우 뚜렷한 음의 상관관계를 나타냈다. 산림 소유역에서는 농경지 소유역에 비해 유량과 총질소(T-N) 및 $K^{+}$의 양의 상관관계가 뚜렷하게 나타났다. 반면, 농경지 소유역에서는 부유물질 총량(TSS), 총인(T-P) 및 화학적 산소요구량(COD)이 유량과 높은 상관성을 보였다. 대관령 지역에서는 도암호의 수질 오염, 특히 T-P의 증가가 심각하다는 점에 비추어 볼 때 수질 개선을 위해서는 농경지의 토양 유실 방지가 매우 중요하다. 특히 고랭지 채소 파종기에 해당하는 6월말에서 7월초에 이르는 기간의 토양 및 양분유실이 가장 심각한 것으로 나타나 이를 줄이기 위한 친환경농법 도입이 요구된다.

• Asian-Australasian Journal of Animal Sciences
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• 제16권4호
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• pp.534-540
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• 2003

This study was conducted to investigate the effect of supplementation of galacto-oligosaccharides (GOS) on methane emission, nutrient digestibility, energy utilization and blood metabolites by Holstein cows fed silages. In two sequential digestion and respiratory trials, two non-lactating Holstein cows were arranged to a balanced incomplete block design. Experimental diets consisted of two silage types; orchardgrass (Dactylis glomerata L.) based silage (OS), mixed silage (orchardgrass based silage and alfalfa (Medicago sativa L.) silage) (MS), while two GOS levels were without supplementation (0) and 2% of dry matter intake supplementation (2). Four combination diets were OS-0, OS-2, MS-0 and MS-2. Significant effects of silage types and GOS supplementation levels were not observed for DM and OM intake. Whereas the digestibility of OM, NDF and ADF was significantly (p<0.05) higher in cows fed OS with and without GOS compared cows fed MS diets. As percentage of GE intake, fecal energy loss for OS diets was significantly (p<0.05) declined than for MS diets. In contrast, cows fed MS diets had lower (p<0.05) urine energy loss as a proportion of GE intake compared to OS diets. Energy loss as CH4 and heat production was numerically increased when cows fed both OS and MS with GOS supplementation. Compared to OS, CH4 emission in cows fed MS was numerically decreased by 10.8 %. Methane conversion ratio (energy loss as CH4 per unit of GE intake) for OS-0, OS-2, MS-0 and MS-2 were 7.1, 7.2, 6.8 and 7.0, respectively. Plasma of glucose and urea-N concentration were significantly (p<0.05) elevated from 1 h to 6 h after feeding, otherwise total protein in plasma was declined (p<0.01) at 6 after feeding.

• Journal of Gastric Cancer
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• 제13권3호
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• pp.136-148
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• 2013

Purpose: To define the role of robotic gastrectomy for the treatment of gastric cancer, the present systematic review with meta-analysis was performed. Materials and Methods: A comprehensive search up to July 2012 was conducted on PubMed, EMBASE, and the Cochrane Library. All eligible studies comparing robotic gastrectomy versus laparoscopic gastrectomy or open gastrectomy were included. Results: Included in our meta-analysis were seven studies of 1,967 patients that compared robotic (n=404) with open (n=718) or laparoscopic (n=845) gastrectomy. In the complete analysis, a shorter hospital stay was noted with robotic gastrectomy than with open gastrectomy (weighted mean difference: -2.92, 95% confidence interval: -4.94 to -0.89, P=0.005). Additionally, there was a significant reduction in intraoperative blood loss with robotic gastrectomy compared with laparoscopic gastrectomy (weighted mean difference: -35.53, 95% confidence interval: -66.98 to -4.09, P=0.03). These advantages were at the price of a significantly prolonged operative time for both robotic gastrectomy versus laparoscopic gastrectomy (weighted mean difference: 63.70, 95% confidence interval: 44.22 to 83.17, P<0.00001) and robotic gastrectomy versus open gastrectomy (weighted mean difference: 95.83, 95% confidence interval: 54.48 to 137.18, P<0.00001). Analysis of the number of lymph nodes retrieved and overall complication rates revealed that these outcomes did not differ significantly between the groups. Conclusions: Robotic gastrectomy for gastric cancer reduces intraoperative blood loss and the postoperative hospital length of stay compared with laparoscopic gastrectomy and open gastrectomy at a cost of a longer operating time. Robotic gastrectomy also provides an oncologically adequate lymphadenectomy. Additional high-quality prospective studies are recommended to better evaluate both short and long-term outcomes.

• Child Health Nursing Research
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• 제10권1호
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• pp.98-107
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• 2004

Purpose: This study was to confirm the effect of acupressure on the emesis control and the weight change among pediatric cancer patients receiving anti-cancer chemotherapy. Method: Forty pediatric cancer patients, receiving the induction stage of chemotherapy with MTX and vincristine, were divided into control(n=20) and the intervention group(n=20). Both groups received regular anti-emesis medication, but the intervention group was added acupressure maneuver for 5 minutes on P6 point for 3 times a day for 5days: before chemotherapy, lunch and dinner by investigator during the hospitalization and by mother at home. The instruments for this study were Rhode's(1986) Index of nausea, vomiting and retching(INVR), Cas electric scale and pamphlet developed by researcher. Result: Significant differences in the degree of nausea and vomiting were observed between the control and the intervention group as measured by INVR(t=4.73; p=.01). Repeated measures ANOVA also shows that the group effect was significant(F=22.39, P=.01) as was the time effect(F=380.35, P=.01). The group by time interaction was also significant(F=5.27, P=.01). Acupressure maneuver was apparently effective in reducing the degree of chemotherapy-induced nausea and vomiting. There were also statistically significant weight loss noted in the control group than the intervention group(t=5.42, p=.01). Conclusion: Acupressure on P6 point shows an effective adjunct maneuver in reducing the degree of nausea and vomiting and conserving the weight in pediatric cancer patients. Therefore, it is proposed that acupressure should be applied as supportive nursing intervention strategies to relieve chemotherapy induced nausea and vomiting and to prevent weight loss in pediatric cancer patients.

• 한국축산식품학회지
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• 제28권2호
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• pp.196-203
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• 2008

본 연구는 한우우사 바닥면의 톱밥두께가 도축후 등심의 육질에 미치는 영향을 구명하고자 실시하였다. 7개월 령의 비거세 수소 22두를 톱밥이 10, 15 및 20 cm로 깔린 단방우사($3{\times}8\;m^2$)에서 27개월령까지 사육한 후 도축하여 등심(M. longissimus) 부위를 $4{\pm}0.2$에서 9일 동안 저장하였다. 도체성적, pH, 보수력, 드립감량, 가열감량, 전단력, 전자코에 의한 향기패턴 및 관능적 기호도는 톱밥두께에 따른 유의적인 차이가 없었다. 일반성분 함량 및 지방산 조성은 20cm가 가장 높은 조지방 함량과 가장 낮은 n6/n3을 보였다(p<0.05). 저장중 총환원력은 9일째에 10cm가 가장 높았던 반면(p<0.05), TBARS는 가장 낮았다(p<0.05). 표면육색소 함량은 저장기간 동안 10 및 20 cm의 MetMb이 15cm보다 낮았던 반면(p<0.05), OxyMb은 높았다(p<0.05). 표면육색은 저장기간 동안 10 및 20 cm가 15 cm보다 붉은 육색을 나타내었다(p<0.05).

• 대한전기학회논문지
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• 제44권3호
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• pp.270-273
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• 1995

This paper proposes an optimal load shedding algorithm by which the system loss can be minimized when the load shedding is unavoidable in case of severe contingency such as the outage of key generators or lines. Shedding load .DELTA.S = .DELTA.P + J.DELTA.Q(MVA) is performed on the weakest bus (on the view of voltage stability), step by step, by the priority of the I.DELTA. = SQRT(.lambda.$\_$P/$\^$2/ + .lambda.$\_$Q/$\^$2/) index given for each load bus, where .lambda.$\_$P/ and .lambda.$\_$Q/ are the sensitivity indices representing the system loss variation versus active and reactive power change of the bus load bus. All loads are assumed to be constant power loads for convenience. A 5 bus sample system proves the effectiveness of the algorithm proposed.

• 유기물자원화
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• 제8권3호
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• pp.81-88
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• 2000

음식쓰레기, 슬러지 등과 같이 C/N비가 낮은 폐기물을 호기성으로 퇴비화하는 경우 질소 성분이 많이 손실될 수 있으며, 이는 비료성분의 손실, 악취를 비롯한 환경오염 발생 등을 유발할 수 있다. 본 연구에서는 퇴비화 공정에서 질소성 물질의 보존방법을 도출하기 위한 기초 연구로 음식쓰레기를 실험실 규모로 퇴비화하면서 일반적인 호기성 퇴비화 공정에서 일어나는 질소의 거동을 분석하였다. 음식쓰레기는 종이나 나무조각과 혼합하여 퇴비화하였으며, 질소성 물질의 거동을 평가하기 위해 퇴비시료에 포함된 암모니아, 산화성 질소, 유기성 질소를 측정하였다. 배가스로 손실되는 질소도 황산으로 흡수시켜 정량하였다. 퇴비화 반응의 활성화 여부가 유기성 질소의 무기화에 큰 영향을 미치는 것으로 조사되었다. 활성이 좋은 퇴비를 식종한 경우 반응 초기부터 유기성 질소의 무기화가 활발히 진행되어 많은 양의 질소가 손실된 반면 초기의 낮은 pH 기간이 길어지면 유기성 질소의 분해가 지연되는 것으로 나타났다. 암모니아 손실량은 주입된 공기량의 영향이 큰 것으로 판단되며, 암모니아 손실이 증가하면 퇴비의 암모니아 함량이 크게 감소하였다. 질소에 대한 물질수지 분석을 통하여 초기 질소의 28~38%가 암모니아로 전환되었으며, 전환된 암모니아의 77~94%가 가스로 손실된 것으로 나타났다.

• 한국재료학회지
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• 제13권6호
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• pp.389-393
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• 2003

The effect of antireflection layer on the reduction of optical loss has been investigated in Si photodiodes detecting red light with central wavelength of 670 nm. The theoretical analysis showed minimum reflection loss of 6% for the $SiO_2$thickness of about $1100∼1200\AA$ in the $SiO_2$-Si system with the single antireflection layer and no reflection loss for the X$N_3$N$_4$$SiO_2$thickness of $2000\AA$/$1200\AA$ in the $Si_3$$N_4$$SiO_2$-Si system with double antireflection layer. In our experiments, Si photodiodes with the web-patterned $p^{＋}$-shallow diffusion region were fabricated by bipolar IC process technology and the devices were classified into three kinds according to the structure of $Si_3$$N_4$/$SiO_2$antireflection layer. The fabricated devices showed maximum spectral response in the optical spectrum of 650∼700 nm. The average photocurrents of the devices with the $Si_3$$N_4$$SiO_2$thickness of $1000\AA$/X$SiO\AA$, and $2000\AA$$1800\AA$ under the incident power, of -17 dBm were 3.2 uA, 3.5 uA and 3.1 uA, respectively.