• Title/Summary/Keyword: Time Scale

Search Result 8,072, Processing Time 0.035 seconds

Mechanisms of Cold Injury and Cultural Practices for Reducing Damage of Rice (벼 냉해발성 기작과 피해 경감대책)

  • Lee, Moon-Hee;Park, Nam-Kyu;Park, Suk-Hong
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.34 no.s02
    • /
    • pp.34-44
    • /
    • 1989
  • The stability of rice cultivation in Korea is largely depended on climatic conditions, especially, low temperature at the period of early growth stage and after heading. The improvement of cold tolerant varieties and appropriate cultural practices in rice are very effective to minimize the cold damage. This paper is summarized the mechanism and counterplans of cold injury of rice plants. The paddy area having commonly cold injury in Korea is approximately 15, 522ha in 1,709 sites on the national scale. The cold damage at seedling stage in nursery bed appeared to poor germination, leaf discoloration, dead seedlings and seedling rot ect.. At the vegetative stage, the decreased tiller number due to poor rooting and the delayed heading caused by slow growth and panicle differentiation are commonly showed. The cold injury at early reproductive stage appeared to the degeneration of spikelets and rachis - branches, while that at meiosis stage showed to increased sterility due to poor development of pollen and shortened panicle length with delaying heading, therefore the grain yield is largely decreased. The cold damage at heading and ripening stages showed to poor pollination and fertilization, low panicle exsertion, poor grain filling and finally grain quality became low. To minimize the cold injury to rice plants by low temperature, following counterplans would be recommonded ; Improvement of the cold toelrant rice varieties for the regions of midmountains and alpines. Raising healthy seedlings at upland nursery beds and by using of growth regulators such as ABA, Fuchiwang and Tachiace. Soil improvement and organic matter application to reduce cold damage by increasing water and fertilizer holding capacities in the paddy field having commonly cold water and in the place where cold damage is regularly occurred. Appropriate fertilization for raising healthy rice plants to tolerate under low temperature condition. Water management to increase water temperature in the paddy such as depth watering, round channels and polyethylene tubes around the field. Establishment of the optimum cultivation time of rice based on minimum, mean and maximum temperatures at different regions with appropriate rice varieties.

  • PDF

Calcium Removal from Effluent of Electronics Wastewater Using Hydrodynamic Cavitation Technology (수리동력학적 캐비테이션을 이용한 전자폐수 처리수에 함유된 칼슘저감에 관한 연구)

  • Park, Jin-Young;Kim, Sun-Jip;Lee, Yong-Woo;Lee, Jae-Jin;Hwang, Kyu-Won;Lee, Won-Kwon
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.29 no.6
    • /
    • pp.715-721
    • /
    • 2007
  • Residual calcium concentration is high, in general, at the effluent of the fluoride removal process in the electronics industry manufacturing semiconductor and LCD. To increase the stability of the membrane process incorporated for reuse of wastewater, the residual calcium is required to be pre-removed. Hyperkinetic Vortex Crystallization(HVC) process was installed in the electronics industry manufecturing semi conductor as a pilot scale for accelerating calcification of calcium ion. Compared to the conventional soda ash method, the 31% higher calcium removal efficiency was achieved when HVC was applied at the same sodium carbonate dosage. In order to maintain the economic calcium removal target of 70% preset by manufacturer, the dosing concentration of the soda ash was 530 mg/L based on influent flowrate. The seed concentration in the reactor was one of the critical factors and should be maintained in the range of $800\sim1,200mg$ SS/L to maximize the calcium removal efficiency. The calcite production rate was 0.30 g SS/g $Na_2CO_3$ in the average. The economic HVC passing time of the mixture was in the range of $2\sim5$ times. Relatively, stable calcium concentration was maintained in the range of $30\sim72$ mg/L(average 49 mg/L) although the calcium concentration in the feed was severely fluctuated with $74\sim359$ mg/L(average 173 mg/L). The HVC process was characterized as environment-friendly technology reducing chemical dosage and chemical sludge production and minimizing maintenance cost.

Characteristic Changes of Swine Manure by Air Suction Composting System (돈분 퇴비화 시 공기 흡입 시스템에 따른 퇴비화 특성 변화)

  • Lee, Dong-jun;Kim, Jung Kon;Jeong, Kwang-Hwa;Cho, Won-Mo;Ravindran, B.
    • Journal of the Korea Organic Resources Recycling Association
    • /
    • v.24 no.3
    • /
    • pp.63-74
    • /
    • 2016
  • The objective of this study was to investigate the variations of physico-chemical properties during the swine manure composting, sawdust as the bulking agent was composted at different points (Top layer, Side of middle layer, Bottom layer). Air suction system with constant bottom aeration in bench scale reactors (30 L). The highest temperature was reached in the range of $58^{\circ}C$ to $62^{\circ}C$ on $3^{rd}$ day and this thermophilic phase (> $50^{\circ}C$) was continued for 3 days in all the treatment mixtures. However, the temperature was gradually decreased to room temperature at the end of 60 day composting process. Except control, the discharged ammonia ($NH_3$) was a maximum in the treatment order of Top layer>Bottom layer>Side of middle layer as 500 ppm, 162 ppm and 120 ppm, respectively, on the $4^{th}$ day and showing that Top layer point Air suction produce much more ammonia content than the other point. During the composting process, the total Kjeldahl nitrogen (TKN) was gradually increased due to the mass loss in the composting mixtures. At the same time, C/N ratio was decreased to Top layer, 13; Side of middle layer, 12 and Bottom layer, 13 at Air suction points. The significant reduction of C/N ratio in all different air suction system when manure was matured. The $NH_4-N$ to $NO_3-N$ ratio was recorded as 10.52 at the initial stage of the compost mixtures and reduced to 0.97 (Top layer), 0.70 (Side of middle layer), 3.2 (Bottom layer) because of manure decomposition. The overall results revealed that Top layer and Side of middle layer Air suction is a suitable option when compared other point for high quality composts.

A Study on Xu Bing's artworks Contributed to expansion of printmaking in Contemporary Chinese Art (중국 현대미술에서의 판화 매체 확장을 일으킨 쉬빙(徐冰) 작품 연구)

  • Song, Dae-Sup;Cho, Ye-In
    • Cartoon and Animation Studies
    • /
    • s.45
    • /
    • pp.321-343
    • /
    • 2016
  • The purpose of this thesis is to look through the political and social background of China preparing for a new era after getting out of the Communist Party of Mao Zedong, rapid inflow of the Western modernism and the avant-garde art arising in China with the focus of art works of Xu Bing, which contributed to the expansion of printmaking of China. Particularly, 85 New Wave Movement arose by young artists since 1985 and the China/Avant-Garde Exhibition held in Beijing in 1989 are the two important issues which reflect a new change from the traditional Chinese art. The artists of 85 New Wave Movement, who pursued a historical revolution and novelty, worked very actively by leading private exhibitions. Since the Cultural Revolution, the government owned the National Museum of Fine Art Beijing had exhibitions on a large scale displaying various visual arts such as performing art, installation, painting, sculpture but the Chinese government interrupted exhibitions two time due to bold performing art and unconcealed installation. Some artists were even taken to the police when performing art. Under these circumstances, Xu Bing, who majored printmaking, produced one of his major works, Books from the sky(1988), while he was working on various experiments focusing on the production process of printmaking and its repetitiveness. Xu Bing devised letters, carved them in trees and finally created approximately 2000 characters. Going further he displayed it as installation work, which means the developed characters go beyond a printed form, for audiences. This made him earn favorable reviews since it was a form of western art coupled with Chinese contents 'Chinese character'. After he received unfavorable reviews, however, he went to America leaving his last work in China, Ghost Pounding the Wall, in 1990, which was not able to exhibited. In those days, China society was going through a chaotic era thanks to the extinction of the Cultural Revolution and Deng Xiaoping's(1904-1997) reformation after the debacle of Tiananmen Massacre. This study looks into Xu Bing's artworks from his initial print works until he went to the US in 1991 and examines how he performed experiments utilizing reproductivity and plurality of prints tinged with Chinese traditional elements, and ultimately became one of the avant-garde artists representing the period.

The effect of rooming-in care on the emotional stability of newborn infants (모자동실이 신생아의 정서적 안정에 미치는 영향)

  • Ahn, So Yoon;Ko, Sun Young;Kim, Kyung Ah;Lee, Yeon Kyung;Shin, Son Moon
    • Clinical and Experimental Pediatrics
    • /
    • v.51 no.12
    • /
    • pp.1315-1319
    • /
    • 2008
  • Purpose : We aimed to examine the effect of rooming-in care on newborn infants emotional stability by comparing them with those cared for in a nursery. Methods : Forty-eight full-term newborn infants born at Cheil General Hospital between July 1 and October 31, 2007, were enrolled. Twenty-four newborn infants were roomed-in in their mothers rooms (rooming-in group), and 24 newborns were cared for in the hospital nursery (the nursery group) for the first 3 days of their lives. Those with perinatal problems that required medical treatment were excluded. By using Brazeltons neonatal behavior assessment scale, we measured irritability and self-quieting as well as the duration of crying after heel-stick puncture for the newborn metabolic screening test. Results : The rooming-in group had a higher irritability score than the nursery group ($6.8{\pm}1.7$ vs. $4.2{\pm}2.1$, P<0.001), thereby suggesting stable behavior against external irritation; the former also had a higher self-quieting activity score ($5.9{\pm}0.3$ vs. $4.5{\pm}1.8$, P=0.001), thereby suggesting that stability was reached quickly from the irritated state. Time taken to stop crying after the heel-stick puncture was significantly shorter in the rooming-in group than in the nursery group ($17{\pm}15.1$ seconds vs. $115.3{\pm}98.5$ seconds, P<0.001). Conclusion : These results show that newborn infants in the rooming-in group exhibit more stable behavior against external irritation and can be stabilized from an irritated state more quickly than infants cared for in the nursery, even after a few days of rooming-in care.

Estimation of Groundwater Table using Ground Penetration Radar (GPR) in a Sand Tank Model and at an Alluvial Field Site (실내 모형과 현장 충적층에서 지하투과레이더를 이용한 지하수면 추정)

  • Kim, Byung-Woo;Kim, Hyoung-Soo;Choi, Doo-Houng;Koh, Yong-Kwon
    • The Journal of Engineering Geology
    • /
    • v.23 no.3
    • /
    • pp.201-216
    • /
    • 2013
  • Ground penetrating radar (GPR) surveys were conducted in a sand tank model in a laboratory and at an alluvial field site to detect the groundwater table and to investigate the influence of saturation on GPR response in the unsaturated zone. In the sand tank model, the groundwater table and saturation in the sand layer were altered by injecting water, which was then drained by a valve inserted into the bottom of the tank. GPR vertical reflection profile (VRP) data were obtained in the sand tank model for rising and lowering of the groundwater table to estimate the groundwater table and saturation. Results of the lab-scale model provide information on the sensitivity of GPR signals to changes in the water content and in the groundwater table. GPR wave velocities in the vadose zone are controlled mainly by variations in water content (increased travel time is interpreted as an increase in saturation). At the field site, VRP data were collected to a depth of 220 m to estimate the groundwater table at an alluvial site near the Nakdong river at Iryong-ri, Haman-gun, South Korea. Results of the field survey indicate that under saturated conditions, the first reflector of the GPR is indicative of the capillary fringe and not the actual groundwater table. To measure the groundwater table more accurately, we performed a GPR survey using the common mid-point (CMP) method in the vicinity of well-3, and sunk a well to check the groundwater table. The resultant CMP data revealed reflective events from the capillary fringe and groundwater table showing hyperbolic patterns. The normal moveout correction was applied to evaluate the velocity of the GPR, which improved the accuracy of saturation and groundwater table information at depth. The GPR results show that the saturation information, including the groundwater table, is useful in assessing the hydrogeologic properties of the vadose zone in the field.

Comparison of the Therapeutic Efficacy of Methylprednisolone Pulse Therapy and Oral Steroid Therapy in Children with IgA Nephropathy and HSP Nephritis Combined with Proteinuria (단백뇨를 동반한 IgA 신병증 및 HSP 신염을 가진 소아에서 메틸프레드니솔론 충격요법과 경구 스테로이드 요법의 비교)

  • Ahn, Ji Young;Moon, Jung Eun;Hwang, Young Ju;Choi, Bong Seok;Ko, Cheol Woo;Cho, Min Hyun
    • Childhood Kidney Diseases
    • /
    • v.18 no.1
    • /
    • pp.24-28
    • /
    • 2014
  • Purpose: The purpose of this study was to assess the therapeutic efficacy of methylprednisolone pulse therapy in children with IgA nephropathy and Henoch- Sch$\ddot{o}$nlein Purpura (HSP) nephritis combined with proteinuria. Methods: We retrospectively reviewed the clinical records of 21 patients who were diagnosed with IgA nephropathy and HSP nephritis based on percutaneous renal biopsy. Of the 21 patients, 15 were diagnosed with IgA nephropathy and 6 were diagnosed with HSP nephritis. They had mild to severe proteinuria at the time of diagnosis or during follow-up. Group 1 (n=7) received methylprednisolone pulse therapy three times every couple of months, and Group 2 (n=14) received oral steroid therapy. The follow-up periods for Group 1 and 2 were 14.0 (9-54) months and 26.5 (14-34) months, respectively. There was no significant difference in the follow-up duration between the two groups. Results: The average age at diagnosis and biopsy was lower in Group 1 compared to Group 2, but it was not significantly different. At admission, all patients in both groups had hematuria and 5 patients (71.4%) of Group 1 and 14 patients (100 %) of Group 2 had proteinuria. Before treatment, there was no significant difference of spot urine protein/creatinine ratio between the two groups. During followup, 7 patients of Group 1 (100%) and 10 patients of Group 2 (71.4%) showed complete improvement of proteinuria and the spot urine protein/creatinine ratio in Group 1 was significantly lower than Group 2. Conclusion: In patients with IgA nephropathy and HSP nephritis with proteinuria, methylprednisolone pulse therapy was more effective than oral steroid therapy in the reduction of proteinuria. To investigate the effects on long-term prognosis, large-scale prospective studies are needed.

Effect of Paddy Drying by Solar Energy Concentration Blast-Grain Circulation Dryer (태양열집열송풍(太陽熱集熱送風), 곡물순환식(穀物循環式) 건조기(乾燥機)의 벼 건조효과(乾燥效果))

  • Lee, B.Y.;Kim, Y.B.;Son, J.R.;Yoon, I.H.;Han, P.J.
    • Applied Biological Chemistry
    • /
    • v.32 no.2
    • /
    • pp.104-108
    • /
    • 1989
  • A 2.5 ton scale of solar energy concentration blast-grain circulation dryer (SECD) was developed in order to shorten the drying time without damaged paddy. Comparative experiments were carried out on performance, drying efficiency, consistency in moisture content, milling recovery, grade of milled rice, and energy requirement and cost against all that of in-bin drying and storage (IBDS) method. The experiments were performed using mixture of several rice varieties of Tongil type(Japonica-Indica breeding type) under the autumn weather in Korea. The circulating air temperature inside SECD was $4{\sim}5^{\circ}C$ higher than that of IBDS. The moisture content of the paddy during the drying period in SECD was uniform while substantially varied in upper, middle or bottom layer in IBDS. By SECD, 24% initial moisture content of paddy was reduced to 15% after only 3 days of drying as compared to 14 days at IBDS. The percentage of cracked kernels in upper, middle and bottom layers in IBDS was 6, 6 and 12%, respectively, whereas 7% in all layers in SECD. Both types of dryers did not significantly affect the milling recovery of dried paddy and grade of milled rice. Energy requirement of SECD(28.8Kw/2.5ton) for paddy drying was much less than that of IBDS(108Kw/2.5ton).

  • PDF

Applications of "High Definition Digital Climate Maps" in Restructuring of Korean Agriculture (한국농업의 구조조정과 전자기후도의 역할)

  • Yun, Jin-I.
    • Korean Journal of Agricultural and Forest Meteorology
    • /
    • v.9 no.1
    • /
    • pp.1-16
    • /
    • 2007
  • The use of information on natural resources is indispensable to most agricultural activities to avoid disasters, to improve input efficiency, and to increase lam income. Most information is prepared and managed at a spatial scale called the "Hydrologic Unit" (HU), which means watershed or small river basin, because virtually every environmental problem can be handled best within a single HU. South Korea consists of 840 such watersheds and, while other watershed-specific information is routinely managed by government organizations, there are none responsible for agricultural weather and climate. A joint research team of Kyung Hee University and the Agriculture, forestry and Fisheries Information Service has begun a 4-year project funded by the Ministry of Agriculture and forestry to establish a watershed-specific agricultural weather information service based on "high definition" digital climate maps (HD-DCMs) utilizing the state of the art geospatial climatological technology. For example, a daily minimum temperature model simulating the thermodynamic nature of cold air with the aid of raster GIS and microwave temperature profiling will quantify effects of cold air drainage on local temperature. By using these techniques and 30-year (1971-2000) synoptic observations, gridded climate data including temperature, solar irradiance, and precipitation will be prepared for each watershed at a 30m spacing. Together with the climatological normals, there will be 3-hourly near-real time meterological mapping using the Korea Meteorological Administration's digital forecasting products which are prepared at a 5 km by 5 km resolution. Resulting HD-DCM database and operational technology will be transferred to local governments, and they will be responsible for routine operations and applications in their region. This paper describes the project in detail and demonstrates some of the interim results.

Study on Present Status of Poultry Farming and Improvement of Technical Management for Poultry Production (양계농가실태와 생산경영기술 개선에 관한 조사연구)

  • 오세정
    • Korean Journal of Poultry Science
    • /
    • v.8 no.2
    • /
    • pp.91-114
    • /
    • 1981
  • This research was carried out from July to August, 1981, to analyse the true state of management, the skill of production, the structure of consciousness about the selected 294 poultry$.$farms, and to know about their bottlenecks and suggestions. The results obtained were as follows: 1. As for manager's ages, 31 to 45 years old men rate was 67.76%. upper 50years old men 15.94%. 2. 79.9% of farm omen possess attainments equal to or higher than those of upper secondary school graduates. 3. In poultry farming career of the investigated person, layer chicken industry was longer than broiler. 4. Occupations of farm owners before. doing poultry farming were farmers(32.35%), company employees, civil servants and soldiers, etc. 5. 58.62% of the person ran only poultry farming and the rest of them held the additional office of a farmer and a public officer. 6. There were many people who made a speciality of poultry farming holding additional jobs as dairy farming, cultivating crops, gardening, etc. 7. 42.35% of the person began poultry farming with under 1,000 layer chickens. And the rate of the ones with 1,000-2,000 broilers for the first time consisted 40.95% 8. Present breeding scale was that the rate of the farmers having 5,000-10,000 layer chickens was 37.13% and the ones having 5,000-10,000 broilers 38.32%. 9. The rate of the person supplying self-labor was 23.16%, the person having 1.3 employees 51.47% and the ones having under 20 employees 1.47%. 10. 74.26% of the poultry farms used very good quality of baby chicks. 11. The rate of the farms which used chicken feed making the point of the quality of it was 65.47% and the ones which bought it on credit 26.62%. 12. 65.47% bought feed directly from factories and 26.62% bought it from commercial agents. 13. The rate of the layer chicken farms paying for feed in cash was 19.39% and the broiler farms 32.74%. Most of the farms bought feed on credit by 30-60 days. 14. They bought the medicine for chicken from animal drug stores or veterinary hospitals. 15. The rate of the person posting up accounts roughly was 47.52% and that of the ones doing them detaily was 43.57%, 40% did not do them because of bother and only 21.22% had their own cashbooks.

  • PDF