• 한국초지조사료학회지
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• 제41권2호
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• pp.84-95
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• 2021

The purpose of this study was to assess the forage productivity and nutritive value of kenaf at different fertilizer application amounts and various stages of maturity. The experiment was conducted from May to September 2020, the amount of 80 kg of kenaf seed/ha was supplied with different types and amounts of nitrogen fertilizer and the plants were harvested at 10-day intervals from different harvesting dates (24^th August and 3^rd, 13^th, 23^rd September). According to the different fertilizer types and application amounts, the highest kenaf height was recorded in the inorganic fertilizer amounts of 200 and 250 kg N/ha and the fresh and DM yield were significantly improved in the inorganic nitrogen amount of 250 kg N/ha. The highest CP and TDN content in the leaf was achieved in the inorganic fertilizer amounts of 150 and 200 kg N/ha, respectively; and the highest TDN content in the stem was also found in the inorganic fertilizer amount of 200 kg N/ha. According to the different harvesting dates, the highest DM ratio was found in the harvesting date of 13th September, the leaf ratio increased with advanced maturity, whereas the stem ratio decreased significantly and the highest DM yield of kenaf was recorded in the harvesting dates of 13^th and 23^rd September. Besides, the highest CP, CF, CA, ADF, NDF and TDN content in the leaf as influenced by different harvesting dates was 15.4, 31.8, 10.2, 22.1, 34.7 and 76.5%, respectively, and the CP, CA, ADF and TDN in stem decreased significantly with advanced maturity of kenaf. In conclusion, the optimal fertilizer amounts and the appropriate harvesting dates for a high forage yield and high-quality kenaf as livestock feed were the inorganic fertilizer application amounts of 200-250 kg N/ha and from 13^th and 23^rd September, respectively.

• 한국식품영양학회지
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• 제35권6호
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• pp.445-452
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• 2022

The quality and antioxidant characteristics of apios (Apios americana Medikus) according to different harvest periods and steaming treatment were investigated. The quality and antioxidant characteristics of apios were significantly different depending on harvest periods. Total starch contents was higher in 1st harvesting period as 62.32 g/100 g than other harvesting period. The water binding capacity and water solubility index was higher in 1^st harvesting period as 228.65 and 11.29% than other harvesting period. The sucrose and total free sugar contents were 3.64~8.67 and 4.49~9.54 g/100 g, respectively. Total polyphenol and flavonoid contents of apios was the highest 2^nd and 4^th harvesting period at 4.21 mg GAE/g and 611.11 ㎍ CE/g, respectively. DPPH radical scavenging activity was higher in 1st harvesting period as 84.96 mg TE/100 g than other harvesting period, and decreased as the harvest periods were delayed. ABTS radical scavenging activity and ferric-reducing antioxidant power were 43.81~47.89 mg TE/g and 231.20~264.07 mM/100 g, and increased to 50.58~51.44 mg TE/g and 342.55~384.29 mM/100 g after heat treatment. As a result, it is thought that studies on change of quality and physicochemical characteristics according to cultivation characteristics should be preceded for cultivation stability of apios.

• 한국인터넷방송통신학회논문지
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• 제22권3호
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• pp.201-206
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• 2022

에너지 하베스팅(Harvesting)은 1954년 미국 벨 연구소가 태양광을 에너지로 바꾸는 태양전지 연구를 진행하면서 소개된 개념이다. 이러한 에너지 하베스팅 기술은 일상생활 속 버려지거나 미활용 되는 에너지를 모아 전력으로 재활용하는 기술로서 에너지를 효율적으로 활용할 수 있게 하는 친환경 에너지 방안 중 하나로서 다양한 에너지를 적용할 수 있다. 특별히 태양광발전시스템의 경우 맑은 날에 비해 흐린 날씨에 전력생산 Loss가 발생하는 형태로 인버터에서 발생하는 전력 소모를 줄이기 위해, 배터리를 이용하여 발생하는 전기를 저장함으로써 에너지 하베스팅을 적용할 수 있다. 따라서 본 논문에서는 일출, 일몰, 흐린 날씨 등의 낮은 일조량 구간에서 에너지 하베스팅 기술을 적용하여 인버터 동작 최저전압 이하 및 소멸하는 전력을 회수하여 발전량을 개선하고자 한다. 이에 따라 태양광발전 전력량에 따른 시스템 및 알고리즘 개발과 일몰, 일출, 그 밖에 환경에서 발전되는 저 전력을 이용한 시스템과 알고리즘 개발을 통해 연구내용을 증명하였다.

• 대한인간공학회지
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• 제36권5호
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• pp.589-599
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• 2017

Objective: The objective of this study was to measure the upper-limb motions and postures of grapes-harvesting tasks using electrical goniometers and analyze the upper-limb motions in a kinematic way to assess the risk of musculoskeletal disorders. Background: Grapes farmers are exposed to various risk factors of musculoskeletal disorders (MSDs) such as repetitive upper-limb motions, non-neutral postures, and manual handling of heavy items. The farmers have to use scissors repetitively while harvesting grapes with their being arms elevated over the shoulder height, which presumed to increase the physical workload. It has been reported that the grapes farmers feel the harvesting task as the one of the hardest work in cultivating grapes. We tried measure the wrist and elbow angles while the farmers were carrying out harvesting tasks to understand how much workload the work impose on the farmers, which can be helpful in making interventions of preventing musculosksletal disorders among grapes farmers. Method: We measured joint angles at the right wrist and elbow with a wireless measuring system with two electrical goniometers from five grape farmers. The grapes-harvesting task was classified into 6 different subtasks: 1) searching, 2) picking, 3) cleaning, 4) carrying, 6) storing, and 7) miscellaneous tasks. The subtasks were compared by mean angles, 10%, 50%, and 90% APDF values of wrist flexion/extension, ulnar/radial deviation, and elbow flexion. Results: The Kruskal-Wallis tests showed that the 10th percentiles of APDF of ulnar/radial deviation and flexion/extension of the wrist significantly differs among subtasks (p<0.05). It was found that the farmers assumed more deviated wrist postures in the ulnar direction when they picking and adjusting the grapes. The use of scissors seemed to force the farmers to severely bend their wrist in the directions of ulnar deviation and flexion. The grapes-harvesting task showed similar wrist postures and motion with poultry deboning and milking tasks. Conclusion: The grapes harvesting tasks make the farmers take ulnar deviated and extended postures in the wrist. The use of scissors makes them take more severely deviated postures in the wrist. Safety guidelines including use of ergonomic scissors can be provided to the farmers to improve their work conditions. Application: The results of this study can be used as a basic data for the development of safety guidelines for agricultural work.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.329-329
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• 2017

The study was conducted to investigate the effects of different harvesting time on pasting properties of starch in three colored rices. Seven major parameters of starch pasting properties, peak viscosity (PKV), hot pasting viscosity (HPV), cool pasting viscosity (CPV), setback (CPV minus PKV), breakdown (PKV minus HPV), peak time, and pasting time were determined by Rapid Visco Analyzer. The peak viscosity, hot viscosity, cool viscosity and peak time were influenced by different harvesting times. Pasting time was delayed slightly with prolonged harvesting time in all rice cultivars. Pasting temperature in each rice cultivar differed from each harvesting time, and pasting temperature of the two rice cultivars, Hongjinju and Joseongheugchal, showed the highest at the 40 days after heading and then it decreased at the final harvesting time. With the delay of the harvesting time, peak viscosity, hot viscosity, cool viscosity, setback value and pasting temperature did not exhibit a regular trend depending on their genetic characteristics. Branch chain length distribution of amylopectin was demonstrated a distinct difference among these colored rices. In changes of amylopectin branch chain-length distribution, the amylopectin structure of Hongjinju rice cultivar as affected by different harvesting time, the shortest chain length of amylopectin in rice starch harvested at 20 days after heading was characterized by the significant increase in A chains with $DP{\geq}12$ and remarked decrease in long chains $37{\leq}DP$ compared to that of 30, 40, and 50 days after heading. In particular, when harvesting time is delayed the distribution percentage of short chain (A chains with $DP{\geq}12$) was increased except for the rice which harvested 20 days after heading. The similar results were also observed in Sintoheugmi rice cultivar like that of Hongjinju rice cultivar. Otherwise, distribution percentage of the shortest chain length of amylopectin in rice starch harvested at 20 days after heading was characterized by the significant decrease in A chains with $DP{\geq}12$ and remarked increase in B chains $13{\leq}DP{\geq}24$ compared to that of 30, 40, and 50 days after heading.

• The Korean Journal of Ecology
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• 제23권1호
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• pp.9-15
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• 2000

이 연구는 성숙활엽수림 개벌수확지에서 벌채로 인한 토양의 화학성분 및 계류수질에 미치는 영향을 구명할 목적으로 1993년부터 1998년까지 전남 광양 백운산 지역 천연활엽수림 벌채지(서울대학교 농업생명과학대학 부속 남부연습림내 제 26 임반)에서 수행하였다. 이 연구를 위하여 1993년에 벌채한 13ha의 벌채지와 이와 연접한 비벌채지를 조사?연구대상지로 선정하였다. 이 조사지 에서 1993년부터 1998 년까지 토양의 화학성분과 계류수질을 측정?분석한 결과, 벌채후 1년, 2년이 경과되는 동안 전질소, 치환성 이온인 K/sup ＋/, Na/sup ＋/, Ca/sup 2＋/, Mg/sup 2＋/은 벌채전 보다 양적으로는 감소하였으며, 벌채후 5년이 경과된 뒤에는 벌채 2년 경과후 보다 유의적으로 증가하였으나, 토양의 화학성분은 변화하지 않았다. 또한, 벌채 당해년도와 그 다음 해,그리고 벌채후 5년이 경과되었을 때 벌채지 계류수의 BOD, pH등은 하천수질환경기준에 의한 상수원수 1급 기준에 도달하였으며, Cd, Pb, Cu 둥 중금속과 유기인은 검출되지 않았다 계류수의 색도, 탁도, 냄새, 맛, NH/sub 4//sup ＋/-N, NO/sub 3//sup -/-N, 일반세균수, 대장균군 둥 8개 항목은 먹는 물 수질기준에 적합하여 벌채지 인근지역 주민들이 음용수로 이용하는 데에는 영향이 없는 것으로 해석되었다. 그러나 계류수질평가항목 중 BOD는 벌채후 1년, 2년이 경과되는 동안 하천수질환경기준에 의한 상수원수 1급 기준의 최고치인 1 ppm에 도달하는 둥 수질이 악화될 우려가 있기 때문에 대규모 산림 벌채계획은 계류수질보전 을 고려하여 시행하여 야 할 것으로 생각된다.

• 한국산림과학회지
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• 제83권3호
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• pp.372-379
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• 1994

본 연구는 서로 다른 두가지 토양에서 천연갱신되어 자라고 있는 trembling aspen(Populus tremuloides Michx.) 임분의 수확이 토양미생물상 및 토양호흡률에 미치는 영향을 조사하며 토양호흡률이 토양미생물상 변이의 지표로 활용될 수 있는지에 대한 연구 결과이다. 다섯 가지의 수확처리(지상부 전체 임목수확, 겨울철 수확통로, 수확 잔재목 제거, 수확 잔재목 및 낙엽류 제거, 춘계 답압)를 1990년과 1991년 사이의 겨울 및 봄 사이에 시행하였고, 1991년 및 1992년의 2년간에 걸쳐 수확후 산림토양의 동태를 조사하였다. 각 임분의 토양형에 관계없이 토양호흡률은 수확후 약간 감소하거나 변동이 없었으나 미생물수는 수확후 2년동안 점차 증가하였다. 미생물수는 식질토양에서 보다 사질토양에서 보다 급속하고 지속적인 증가양상을 나타내었는데, 이것은 수확 결과 미생물 활성에 영향하는 토양의 이화학적 특성이 식질토양보다는 사질토양에서 큰 변화가 있었음을 시사한다. 그러나, 두가지 종류의 처리(세 수준의 유기물 제거 및 두 수준의 답압 처리)는, 두 지역 모두, 수확후 2년간의 미생물상이나 토양호흡률에 유의차를 나타내지 않았다. 본 연구의 대상임분이었던 trembling aspen은 수확후에도 뿌리의 활력이 떨어지지 않고 맹아발생을 위한 대사를 진행하여, 뿌리의 호흡과 미생물의 호흡을 포함하는 전체 토양 호흡에서 뿌리의 호흡이 차지하는 비율이 높은 결과를 낳아, 전체 토양호흡을 미생물의 활력도 변이의 지표로 활용하기 어려웠다.

• 한국작물학회지
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• 제54권1호
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• pp.7-12
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• 2009

녹두는 생리적 특성과 재배지역의 기상조건 등에 따라 여러 번 수확해야한다. 한국에서는 일반적으로 6월에 파종하여 $3{\sim}4$회 가량 수확하므로 녹두 재배면적이 급격히 감소하고 있다. 따라서 한국 남부지역의 기상조건에 맞는 기계수확 재배기술을 개발하고자 본 연구를 수행하였다. 남부지역에서 기계수확을 위한 최적 파종기는 7월 20일 경 이었다. 7월 15일 경에 파종하였을 때는 2회 수확해야 하므로 기계수확이 불가능하였다. 7월 25일 이후 파종하였을 때는 기계수확이 가능하였으나 성숙기간이 길어지고 수량이 적었다. 그러므로 한국에서는 남부지역 7월 20일 기준으로 중부지역은 이전에 남부해안지역은 이후에 파종하면 녹두 기계수확이 가능할 것으로 보아진다. 한국에 가장 많이 보급된 금성녹두와 어울녹두 중에 어울녹두가 기계수확 재배에 적합한 품종이었다. 즉 어울녹두는 금성녹두에 비해 경장이 길고 착협고가 높아 기계수확에 유리할 뿐만 아니라 수량이 많았다.

• 한국물환경학회지
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• 제24권2호
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• pp.230-238
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• 2008

This study evaluated the economic aspect of the rainwater harvesting facilities by hydrologically analyzing the inflow, rainwater consumption, rainfall loss, tank storage, and overflow time series to derive the net rainwater consumption and the number of days of rainwater available. This study considers several rainwater harvesting facilities in Seoul National University, Korea Institute of Construction Technology and Daejon World Cup Stadium and the results derived are as follows. (1) Increasing the water consumption decreases the number of days of rainwater available. (2) Due to the climate in Korea, a larger tank storage does not increase the amount and the number of days of water consumption during wet season (June to September), but a little in October. (3) Economic evaluation of the rainwater harvesting facilities considered in this study shows no net benefit (private benefit). (5) Flood reduction effect of rainwater harvesting facilities was estimated very small to be about 1% even in the case that 10% of all the basin is used as the rainwater collecting area.

• 상하수도학회지
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• 제19권1호
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• pp.31-37
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• 2005

One of the major obstacles confronted in promoting the rainwater harvesting is the concerns of acid rain and heavy metals. Although there are many data concerning the quality of rainwater precipitation for the study of acid rain, the study on the quality of stored rainwater has been limited. In this study, we monitored the quality of stored rainwater at Galmoe middle school, where a rainwater harvesting system is installed and in use for more than two years. We measured water quality parameters such as pH, Electro Conductivity(EC), Dissolved Oxygen(DO), and some metals (aluminium (Al), chromium(Cr), manganese(Mn), zinc(Zn), copper(Cu), arsenic(As), cadmium(Cd), lead(Pb)). The monitoring period was during one year from September 9th 2003 to August 5th 2004. It was observed that the average pH of stored rainwater is neutral. DO is similar to tap water and EC is lower than tap water. Metal Concentrations are within the concentration specified in Drinking Water Quality Standard. Overall, the stored rainwater quality is good enough for sundry use and there's no threat of acid rain and air pollution, if the rainwater harvesting system is well designed and maintained.