• Title/Summary/Keyword: inclined condition

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Pre-sowing Treatments to Improve Germination of Intact Seeds in Burcucumber (Sicyos angulatus L.) (가종피가 부착된 안동대목 종자의 발아율 향상을 위한 파종전 종자처리)

  • 강진호;전병삼;윤수영;이상우;정종일
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.48 no.3
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    • pp.169-172
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    • 2003
  • Intact seeds of burcucumber (Sicyos angulatus L.) are not nearly germinated so that the farmers remove their arils before sowing. The study was carried out to measure the effort of aging, chilling, washing, chemical treatment, drying, and their sequential treatments on the germination of ones with arils and the seedling emergence. The seeds extruding over 1mm of their radicles and the seedlings with fully expanded cotyledons were counted daily for calculating the germination and the seedling emergence rates. Seedcoat softening using 10% NaOH solution somewhat enhanced their germination rate of the intact seeds harvested in the current year, but aging treatment done on 6 days at $45^{\circ}C$ after NaOH treatment increased the germination rate more than only NaOH treatment. A day washing after the NaOH treatment and a day chilling after the washing increasingly elevated the rates as well. Irrigation of 0.2% $\textrm{KNO}_3$ solution, moreover, showed the greatest germination rate of the priming treatments done during all the 7 day chilling. Drying the seeds after the combined treatment of chilling and priming more inclined the germination rate than nondrying ones, but red light treated during 24 hour desiccation was more effective in the germination rate increment than dark condition. The seeds done the sequential treatments of aging, NaOH, washing, combining chilling and priming and drying under red light illumination were germinated up to 80% but seedlings were emerged to 60%, lower than ones removed their arils.

Development of hiting sesamer thresher (타격식 참깨탈곡기 개발)

  • 박회만;정성근;홍성기;최희석;홍현유
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 2003.07a
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    • pp.309-316
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    • 2003
  • Generally, sesame are dried on the field after being harvested in Korea. Since harvesting season is rainy autumn and sesame drying is mainly affected sun and natural wind, it is difficult to dry sesame in time. Moreover, sesame threshing by hand is very laborious work. Therefore, tractor mounted sesame thresher which threshes sesame bundles fed in upside down and conveyed along threshing bar was developed to mechanize sesame threshing and to reduce labor cost in this research. the thresher was equipped with a threshing bar which beats sesame bundles and a three layer sieve which screens sesame. The results are summarized as follows ; 1 The sesame thresher was consisted of a hitting-stick, a feeding chain conveyor, a threshing bar, conveyor belt, and the three-layer shaking sieve. 2. In threshing test, prototype thresher showed maximum threshing ratio 98.5%, 98.7% at 14, 17 cpm beating rate respectively. 3. In screening test, prototype sieve showed maximum threshing ratio 97.2% at 12$^{\circ}$ of inclined angle and 220 cpm of sieve vibrating rate. 4. Prototype showed 98.7% of threshing ratio, 1.3% of threshing loss, 97.0% of screening ratio, 0.7% of screening loss on the rest condition of 15 sesame bundles/min of feeding rate, 14 cpm of beating rate, 220 cpm of sieve vibrating rate. 5. The working performance of prototype was 0.5hr/10a. It was 9.6 times more efficient than manual work. And, operation cost of prototype was saved by 45.9% compared to manual work.

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A study on the development and performance evaluation of duct coupling for the minimized leakage of temporary ventilation duct (공사 중 환기덕트 누풍 최소화를 위한 접속부 개발 및 성능평가 연구)

  • Jo, Hyeong-Je;Jun, Kyu-Myung;Min, Dea-Kee;Kim, Jong-Won;Beak, Jong-Hoon
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.20 no.1
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    • pp.145-160
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    • 2018
  • Long subsea tunnel is subject to many restrictions in terms of spatial limitation when vertical or inclined shafts are built for tunnel ventilation. So, the construction of some artificial island is required to provide ventilation. But, because of construction difficulty and cost increase, it is necessary to minimize the artificial island construction. As a result, ventilation distance become longer and supply airflow becomes excessive due to air leakage, So, duct mounting for temporary ventilation is impossible or fan pressure and power increase exponentially. Therefore, in order to build a long subsea tunnel, it is necessary to overcome these practical problems and to develop technical solution that can keep the comfortable condition of tunnel environment during construction. In previous study, we have found that air leakage is the key factor in solving these problems and experimental results show that the new connection method has a leakage rate of about $1.46mm^2/m^2$ (Jo et al., 2017). In this study, we present the experimental results of the measurement of the leakage rate of the prototype with the new connection method, and analyze experimentally the improvement of the leakage rate when applying the flexible cover inside the duct to improve the leakage performance of the existing connection method.

A numerical study of the air fuel ratio effect on the combustion characteristics in a MILD combustor (공연비 변화가 MILD 연소 특성에 미치는 영향에 관한 해석적 연구)

  • Ha, Ji-Soo;Kim, Tae-Kwon;Shim, Sung-Hoon
    • Journal of Korean Society of Environmental Engineers
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    • v.32 no.6
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    • pp.587-592
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    • 2010
  • A numerical analysis of reactive flow in a MILD(Moderate and Intense Low oxygen Dilution) combustor is accomplished to elucidate the characteristics of combustion phenomena in the furnace with the variation of air fuel ratio. For the smaller magnitude of air injection velocity(10 m/s), the air flow could not penetrate toward upper part of furnace. On the other hand, the air flow suppresses the fuel flow for the case of air injection velocity 30 m/s. The air velocity 18 m/s is corresponding to the stoichiometric air flow velocity, and for that case, the air flows to relatively more upper part of the furnace when compared with the case of air injection velocity 10 m/s. The reaction zone is produced with the previous flow pattern, so that the reaction zone of the air injection velocity 10 m/s is biased to the air nozzle side and for the case of air injection velocity 30 m/s, the reaction zone is inclined to the fuel nozzle side. For the cases with the air injection velocities 16, 18, 20 m/s, the reaction zone is nearly located at the center between air nozzle and fuel nozzle. The maximum temperatures and NOx concentrations for the cases of air injection velocity 16, 18, 20 m/s are lower than the cases with air injection velocity 10, 30 m/s. From the present study, the stoichiometric air fuel ratio is considered as the most optimal operating condition for the NOx reduction.

An Analytical Study of the Effect of Inclined Angle of Road on Turn-over Accident of a High-speed Coach running on a Curved Road under Cross-wind Condition (횡풍이 작용하는 속도로의 회전구간에서 도로의 편경사각이 주행차량의 전복사고에 미치는 영향에 관한 분석연구)

  • Park, Hyeong-Su
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.1
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    • pp.373-381
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    • 2017
  • Kyeonggi Provincial Government is considering double decker bus service to solve the problem of heavy rush hour traffic. However, the height-to-width ratio is more than 1.16 times larger than that of a general high-speed single decker bus, and the center of gravity is higher. This could cause driving stability problems, such as turnover and breakaway from the lane, especially under strong side-wind conditions at high speed. In this numerical study, the driving characteristics of a model double decker bus were reviewed under side-wind and superelevation conditions at high driving speed. The rolling, pitching, and yawing moment of the model bus were calculated with CFD numerical simulation, and the results were compared to the recovery angular moments of the model bus to evaluate the dynamic stability under given driving conditions. As the model vehicle moves on a straight level road, it is stable under any side-wind conditions. However, on a curved road under side-wind conditions, it could reach unstable conditions dynamically. There is a chance that the bus will turn over when it moves on a curved road with a radius of gyration less than 100 m under side-wind (15 m/s). However, there is a very small chance of breakaway from the lane under any driving conditions.

Amber Information Design for Supporting Safe-Driving Under Local Road in Small-scale Area (국지지역에서의 안전운전 지원을 위한 경보정보 설계)

  • Moon, Hak-Yong;Ryu, Seung-Ki
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.9 no.5
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    • pp.38-48
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    • 2010
  • Adverse weather (e.g. strong winds, snow and ice) will probably appear as a more serious and frequent threat to road traffic than in clear climate. Another consequence of climate change with a natural disastrous on road traffic is respond to traffic accident more the large and high-rise bridge zone, tunnel zone, inclined plane zone and de-icing zone than any other zone, which in turn calls for continuous adaption of monitoring procedures. Accident mitigating measures against this accident category may consist of intense winter maintenance, the use of road weather information systems for data collection and early warnings, road surveillance and traffic control. While hazard from reduced road friction due to snow and ice may be eliminated by snow removal and de-icing measures, the effect of strong winds on road traffic are not easily avoided. The purpose of the study described here, was to design of amber information the relationship between traffic safety, weather, user information on road weather and driving conditions in local-scale Geographic. The most applications are the optimization of the amber information definition, improvements to road surveillance, road weather monitoring and improved accuracy of user information delivery. Also, statistics on wind gust, surface condition, vehicle category and other relevant parameters for wind induced accidents provide basis for traffic control, early warning policies and driver education for improved road safety at bad weather-exposed locations.

A study on the characteristics for temporary ventilation of long subsea tunnels - focused on the current situation and improvement requirements (초장대 해저터널의 공사중 환기 특성에 관한 기초연구 - 현황 및 개선필요사항 중심)

  • Jo, Hyeong-Je;Chun, Kyu-Myung;Kim, Jong-Won;Lee, Ju-Kyung
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.17 no.2
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    • pp.153-166
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    • 2015
  • Long subsea tunnel to be built below the seabed, as compared to the general railway tunnel, is subject to many restrictions in terms of spatial limitation when vertical or inclined shafts are built for the purpose of ventilation and fire safety. So, the construction of some artificial island is required to provide ventilation. But, because of construction difficulty and cost increase, it is necessary to minimize the artificial island construction. The longer ventilation distance is, the more fresh air requirement is needed. When supply airflow becomes excessive, duct size is restricted by the limitations of structure clearance and fan pressure and power increase exponentially. Therefore, in order to build a long subsea tunnel, it is necessary to overcome these practical problems and to develop technical solution that can keep the comfortable condition of tunnel environment during construction. In this study, as on ventilation method development suitable for long subsea tunnel, through comparison of temporary ventilation capacity calculation methods during construction phase, domestic and abroad, the application of Swiss SIA 196 code is found suitable for long subsea tunnel. And, through experiment on leakage of the duct connector, we confirmed that the leakage ratio per 100 m of domestic duct connection type is between 1.5~3.0%. Based on S-class duct of SIA 196 code, ventilation distance is 10.2 km, So, ventilation distance can be longer if duct connection method is improved. So, we confirmed that the improvement of leakage ratio is key issue in the construction-phase ventilation of long subsea tunnel.

A Study on the Intake Patterns of Health Food of the Elderly Aged over 60 Years in the Chuneheon Area (춘천지역 60세 이상 노년층의 건강식품 섭취실태 조사)

  • 이희섭;이혜숙;이정애;강금지
    • Korean Journal of Community Nutrition
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    • v.6 no.4
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    • pp.635-644
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    • 2001
  • This study was carried out to investigate the intake patterns of health food according to the kind of disease of the elderly aged over 60 years living in the Chuncheon area. This study was conducted by using a questionnaire from December 1999 to the March 2000. The data was analyzed using a SPSS program. The results were summarized as follows : The poorer the self- perceived health condition, the lower the level of activity of daily living(ADL) and instrumental activities of daily living(IADL) were the higher. the frequency score of health food intake. The incidence of disease, such as arthritis(44.7%), hypertension(18.8%), digestive diseases(17.1%), diabetes(10.5%) were found to be higher. than other chronic diseases among the elderly. The frequency score of health food intake was not significantly different according to self-perceived health status, disease status, or the level of ADL and IADl.. The must important source of information for health food intake was the recommendation of friends and relatives(68.7%). Twenty eight point two percent of the elderly considered health foods to be effective, however 8.3% of the elderly considered them to be ineffective. The elderly with chronic diseases had taken health floods in the descending order of neuralgia-arthritis, hypertension, digestive disease, diabetes. The elderly with digestive diseases, diabetes, renal disease, neuralgia- arthritis and respiratory disease were inclined to habitually take health floods once or twice per year. Intake of Korean traditional folk food was as high as intake of registered health food and Chinese tonic medicine. The most frequently taken health food was tonic medicine, which is fo11owed by pumpkin, ginseng products, herbal tea formula with black goat, deer antler and Kye-so-ju. Intakes of health food such as tonic medicine, blood of the deer, royal jelly, aloe were found to be higher among the elderly with chronic diseases such as diabetes, hypertension, and digestive disease. However, intakes of ginseng products, deer antler, pumpkin, herbal tea formula with black goat and Kye-so-ju were found to be higher among the healthy elderly. The elderly with neuralgia-arthritis had taken sixteen kinds of health foods. From these results, a wide consumer education program should be developed to convince people of the importance of well-balanced diet and to choose proper health foods according to the elderly's health conditions. Also, comprehensive and scientific research into Korean traditional folk foods are needed for the correct use.

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A Study on Evaluation Analysis of Wind Formation Function using KLAM_21 -The Case of Daegu City- (KLAM_21을 활용한 바람생성기능 평가분석 연구 -대구시를 대상으로-)

  • Ryu, Ji-Won;Jung, Eung-Ho;Kim, Dae-Wuk;Cha, Jae-Gyu;Son, Kyung-Su
    • Journal of the Korean Association of Geographic Information Studies
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    • v.11 no.2
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    • pp.85-92
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    • 2008
  • This study, the one concerning the evaluation analysis of the function of the wind generation using KLAM_21, has examined closely how the wind really flows on the space of the city, working with the object of case location. In the first place, the cold air formed at upper stream of Sincheon river, a ravine of whole area of Gachang gully and an inclined plane of neighboring mountainous district, flows to the north and expands itself along the upper stream of the Sincheon river, and as the time passes, it is tending upwards in the change of the volume and height as well as of the velocity and direction, of the cold air. It was learned that this phenomenon has made it clear that the spatial features of this area give rise to very good condition in generating and flowing the cold air. Meanwhile, it has been shown that in the area of park in the Ap-mountain, the generation and flow of the cold air are much interrupted because of the overpass traversing the whole area of the park of Ap-mountain, the congested area of large-scaled apartments and the urban development activities constructing the building in the park, and the volume and height of the cold air has been grown very small. In conclusion, It has been learned that for maximization of the spatial effect of the wind corridor, the areas where the cold air is generated, flowed, accumulated, and maintained, have to be connected spatially, and this spatial connection has a close relation with spatial features of the area.

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Scale Model Studies for Stability Estimation of Twin Tunnels with Small Clearance (근접병설터널의 안정성 평가를 위한 모형실험 연구)

  • Kim, Pyoung Gi;Kim, Jong Woo
    • Tunnel and Underground Space
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    • v.23 no.2
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    • pp.130-140
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    • 2013
  • In this study, scaled model tests were performed to investigate the stability of twin tunnels with small clearance, where the pillar widths were 0.5D and 0.25D, respectively. The tunnels were supposed to be constructed in anisotropic weathered rocks with $30^{\circ}$ inclined bedding planes, and the model tests were conducted under the condition of lateral pressure ratio, 1. Six types of test models which had respectively different pillar widths and support conditions were experimented, where crack initiating pressures, maximum pressures, failure modes of pillar and deformation behaviors around tunnels were investigated. The models with wider pillar were cracked under higher pressure than the models with shallower pillar. The models with lining support were cracked under higher pressure and showed less tunnel convergence than the unsupported models. The models with both lining and pillar reinforcement were proved to be most stable among the tested models. In particular, as the model of 0.25D pillar width with only lining support showed shear failure of pillar according to the existing bedding planes, so both lining and pillar reinforcement were thought to be indispensable in that case of tunnel.