• Title/Summary/Keyword: area reduction

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Prediction of Labor Requirement and Cost of Pick-up Type Pulse Crop Harvester for Soybean and Red Bean Harvesting

  • Yoo, Soonam;Chang, Heesoo
    • Journal of Biosystems Engineering
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    • v.39 no.4
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    • pp.283-289
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    • 2014
  • Purpose: This study was carried out to evaluate the labor requirement and the cost-reducing effects of the pick-up type pulse crop harvester compared with those of conventional harvesting for soybeans and red beans. Methods: The labor requirement and the cost to gather, thresh, and clean for conventional harvesting operations were surveyed; those for the pick-up type pulse crop harvester were estimated for soybeans and red beans. The annual capacity of the harvester and the break-even area of the two harvesting methods were also estimated. Results: For soybean harvesting, the labor requirement of 0.57 hour-persons/10 a for the pick-up type pulse crop harvester reflects a 91.9% reduction in the labor requirement of 7.00 hour-persons/10 a for conventional harvesting. Machinery costs of 51,300 won/10 a for the harvester were estimated for an annual harvesting area of 52.5 ha/year, representing a reduction of 33.3% from the 78,700 won/10 a cost of conventional harvesting. A break-even area of 28.4 ha was estimated for the two harvestings. For red bean harvesting, the labor requirement of 0.57 hour-persons/10 a for the harvester reflects a 92.6% reduction in the labor requirement of 7.66 hour-persons/10 a for conventional harvesting. For an annual harvesting area of 52.5 ha/year, annual capacity of 52.5 ha/year and machinery costs of 51,700 won/10 a were estimated for the harvester, reflecting a reduction of 44.7% in the cost of 93,500 won/10 a for conventional harvesting. A break-even area of 23.1 ha was estimated for the two harvestings. A governmental subsidy for purchasing the harvester could contribute to reducing the break-even area and harvesting costs. Conclusions: The pick-up type pulse crop harvester for soybean and red bean harvesting could reduce the labor requirement and costs of conventional harvesting, and a governmental subsidy for purchasing the harvester will improve the economics of the harvester for efficient mechanical harvesting.

A Study on the Corner Filling in the Drawing of Quadrangle Rod from Round Bar (원형봉에서 사각재 인발 공정의 코너 채움에 관한 연구)

  • 김용철;김동진;김병민
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.6
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    • pp.143-152
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    • 2000
  • The comer filling in shaped drawing process is an important characteristic, unlike the round drawing. It has also influence on the dimensional accuracy of the product. In this study, therefore, the shaped drawing process has been simulated by the three dimensional rigid-plastic finite element method in order to investigate the effect of process variables such as reduction in area and semi-die angle to the corner filling. The artificial neural network has also been introduced to reduce the number of simulations. To verify the results of simulations, experiments have been performed on the real industrial products. According to the results, the main process variable on the corner filling is the combination of semi-die angle in the irregular shaped drawing processes, but in the case of regular shaped drawing processes, reduction in area has great influence on the corner filling.

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Comparing floor height reduction effect of slim floor system with square steel pipe (각형강관을 이용한 슬림플로어 시스템의 층고절감효과 비교)

  • Cho, Youn-Jin;Rhim, Hong-Chul;Kim, Dae-You;Lyu, Seung-Il;Kim, Do-Kyun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2017.05a
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    • pp.56-57
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    • 2017
  • In recent years, new construction methods have been required to reduce the construction cost and increase the available area in an environment where construction work is frequently performed in a narrow urban area like Korea. As a result of these studies, slim floor composite beam has been suggested. Slim floor composite beam can reduce required depth because web of steel beam is embedded in the slab, so it is effective to reduce floor height and increase the available area. The purpose of this study is the floor height reduction evaluation by comparing system consisting of reinforced concrete, steel, and slim floor using square-shape steel pipe. After doing structural design for a typical plan, checked effectiveness by comparing each design plan. It is proven that slim floor composite beam can reduce required depth effectively comparing required materials of other system.

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Effects of Drawing Parameters on Mechanical Properties in High Frequency Induction Welded Tubes of BAS111 Alloy for Heat-exchangers (열교환기용 BAS111합금 고주파유도용접관에서 인발조건이 기계적 특성에 미치는 영향)

  • 국진선;김낙찬;송중근;전동태
    • Journal of Welding and Joining
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    • v.22 no.4
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    • pp.65-72
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    • 2004
  • The aim of this study is to investigate the optimum drawing parameter for BAS111 welded tubes. The BAS111 aluminium alloy tubes with 25.4mm in external diameter and 1.5mm in thickness for heat-exchangers were manufactured by high frequency induction welding with the V shaped convergence angle 6.8$^{\circ}$ and power input 50㎾. With increasing the reduction of area (1.6, 5.8, 11.5, 14.2, 18.5, 22.5%) by drawing, tensile strength was increased and elongation was decreased. With increasing the reduction of area by drawing, hardness in weld metal increased rapidly, while that of base metal increased slowly. In the specimen with the outer diameter smaller than 22mm, hardness of weld metal was higher than that of base metal. The optimum drawing parameter of area reduction was estimated about 15% because of the work hardening of welds.

Effects of Microstructural Parameters on the Reduction of Area in Hyper-eutectoid Steel Wires (과공석 강선에서 미세조직 인자들이 단면감소율에 미치는 영향)

  • An, K.S.;Park, J.H.;Bae, H.J.;Nam, W.J.
    • Transactions of Materials Processing
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    • v.25 no.5
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    • pp.306-312
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    • 2016
  • Effects of manufacturing conditions, such as austenitizing temperature, patenting temperature and carbon content in steels, on mechanical properties, especially on reduction of area (RA), of hyper-eutectoid steel wires were investigated. RA increased and then decreased with transformation temperature. This was attributed to the presence of abnormal structures in steels transformed at low transformation temperatures and the occurrence of shear cracking during tensile testing of steels transformed at high transformation temperatures. The increase of austenitizing temperature resulted in the increased austenite grain size and consequently the decrease of RA. The decrease of RA with increasing the carbon content in steels was attributed to the increased fraction of cleavage fracture in tensile fractured surfaces.

Redox Property of Vanadium Oxide and Its Behavior in Cataltic Oxidation

  • 김영호;이호인
    • Bulletin of the Korean Chemical Society
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    • v.20 no.12
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    • pp.1457-1463
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    • 1999
  • Structure and their redox property of the vanadium oxides prepared by decomposing NH₄VO₃ at various temperatures were studied by XRD, SEM, XPS, and temperature programmed reduction/temperature programmed oxidation (TPR/TPO) experiment. All TPR profiles have two sharp peaks in the temperature range 650-750℃, and the area ratio of the two sharp peaks changed from sample to sample. There were three redox steps in TPR/TPO profiles. The oxidation proceeded in the reverse order of the reduction process, and both the reactions proceeded via quite a stable intermediates. The changes of the morphological factor $(I_{(101)}/I_{(010)})$, the ratio of $O_{1S}$ peak area (O$_{1S}$( α)/O$_{1S}$( β)) in the XPS results, and the ratio of hydrogen consumption in TPR profiles with various vanadium oxides showed the distinct relationship between the structural property and their redox property of vanadium oxides. The change of the specific yield of phthalic anhydride with various vanadium oxides showed a very similar trend to those of the peak area ratio in TPR profiles, which meant that the first reduction step related to the partial oxidation of o-xylene on the vanadium oxide catalyst.

Comparing Carbon Reduction Estimates for Tree Species from Different Quantitative Models

  • Hyun-Kil Jo;Hye-Mi Park
    • Journal of Forest and Environmental Science
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    • v.39 no.3
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    • pp.119-127
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    • 2023
  • In this study, quantitative models were applied to case parks to estimate the carbon reduction by trees, which was compared and analyzed at the tree and park levels. At the tree level, quantitative models of carbon storage and uptake differed by up to 7.9 times, even for the same species and size. At the park level, the carbon reduction from quantitative models varied by up to 3.7 times for the same park. In other words, carbon reduction by quantitative models exhibited considerable variation at the tree and park levels. These differences are likely due to the use of different growth environment coefficients and annual diameter at breast height growth rates and the overestimation of carbon reduction due to the substitution of the same genus and group model for each tree species. Extending the annual carbon uptake per unit area of the case park to the total park area of Chuncheon a carbon uptake ranging from a minimum of 370.4 t/yr and a maximum of 929.3 t/yr, and the difference can reach up to 558.9 t/yr. This is equivalent to the carbon emissions from the annual household electricity consumption of approximately 2,430 people. These results suggest that the indiscriminate application of quantitative models to estimate carbon reduction in urban trees can lead to significant errors and deviations in estimating carbon storage and uptake in urban greenspaces. The findings of this study can serve as a basis for estimating carbon reduction in urban greening research, projects, and policies.

The Analysis of Sediment Reduction Effect by Installing Check Dams at Domestic Multi-Purpose Dams (국내 다목적 댐의 저사댐 설치에 따른 퇴사저감 효과 분석)

  • Choi, Gye-Woon;Kim, Kwang-Nam;Han, Man-Shin;Yun, Yong-Jin
    • Journal of the Korean Society of Hazard Mitigation
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    • v.11 no.3
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    • pp.183-189
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    • 2011
  • In this study sediments reduction effects on dam have been analyzed in the case of check dam installation in the upstream. Analyzed sediment reduction effects of 27 points conducted for 10 multi-purposes dam, which is target of this study. According to regression analysis result, Sediment reduction effect by installing check dam has shown inclination which increase as area ratio rises. According to analysis result, sediment reduction effect was greatest in Geum-river point at Daecheong-dam. The life-time is estimated to increases about 60% by installing check dams. When Area ratio increases, it was deduced through regression analysis that rise Sediment Reduction Effect by installing check dam. This study can be useful for the management and design plans like the dam's site or priority for placing. Furthermore, it would be able to construct an efficient sand depositing dam if complementary is provided by being considered catchment area and lucrative property.

Analyzing the Changes in O3 Concentration due to Reduction in Emissions in a Metropolitan Area : A Case Study of Busan during the Summer of 2019 (대도시 지역의 배출량 저감에 따른 O3 농도 변화 분석: 부산광역시 2019년 여름 사례 )

  • Hyeonsik Choe;Wonbae Jeon;Dongjin Kim;Chae-Yeong Yang;Jeonghyeok Mun;Jaehyeong Park
    • Journal of Environmental Science International
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    • v.32 no.7
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    • pp.503-520
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    • 2023
  • In this study, numerical simulations using community multiscale air quality (CMAQ) were conducted to analyze the change in ozone (O3) concentration due to the reduction in nitrogen oxides (NOx)andvolatile organic compounds (VOCs) emissions in Busan. When the NOx and, VOCs emissions were reduced by 40% and, 31%, respectively, the average O3 concentration increased by 4.24 ppb, with the highest O3 change observed in the central region (4.59 ppb). This was attributed to the decrease in O3 titration by nitric oxide (NO) due to the reduction of NOx emissions in Busan, which is classified as a VOCs-limited area. The distribution of O3 concentration changes was closely related to NOx emissions per area, and inland emissions were highly correlated with daily maximum concentrations and 8-h average O3 concentrations. Contrastingly, the effect of emission reduction depended on the wind direction. This suggests that the emission reduction effects may vary depending on the environmental conditions. Further research is needed to comprehensively analyze the emission reduction effects in Busan.

Assessment of the Particulate Matter Reduction Potential of Climbing Plants on Green Walls for Air Quality Management

  • Jeong, Na Ra;Kim, Jeong-Hee;Han, Seung Won;Kim, Jong-Cheol;Kim, Woo Young
    • Journal of People, Plants, and Environment
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    • v.24 no.4
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    • pp.377-387
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    • 2021
  • Background and objective: To improve air quality, particulate matter (PM) can be reduced using green infrastructure. Therefore, in this study, we aimed to determine the particulate matter reduction potential of climbing plants used for green walls, an element of vertical green infrastructure. Methods: A sealed chamber with controlled environmental variables was used to assess the PM reduction level caused by climbing plants. PM concentration in the plant chamber was measured after two and four hours of PM exposure, and the reduction potential was assessed based on the leaf area. Results: Compared to the empty chamber (Control), the PM reduction speed per hour was higher in the plant chamber, which confirmed that climbing plants contribute to the reduction of PM in the air. The PM reduction speed immediately after exposure in the plant chamber was high, but this slowed over time. Additionally, PM has been continuously reduced in plants with large leaves. As a result of calculating the particulate matter reduction level based on leaf area, it was found that there was a difference by particle size. Actinidia arguta, Parthenocissus tricuspidata, Trachelospermum asiaticum, and Euonymus fortunei var. radicans showed a high reduction effect. The trichomes on the leaf surface of Trachelospermum asiaticum were found to affect PM reduction. Conclusion: PM adsorption on the leaf surface is an important factor in reducing its concentration. It was possible to compare different plants by quantifying the amount of PM reduction during a fixed time period. These results can be used as the basic data to select the plant species suitable for urban green walls in terms of PM reduction.