• Title/Summary/Keyword: saving water

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Mitigation of Greenhouse Gas Emissions (GHGs) by Water Management Methods in Rice Paddy Field

  • Kim, Gun-Yeob;Park, Woo-Kyun;Lee, Sun-Il;Lee, Jong-Sik;Choi, Eun-Jung;Na, Un-sung;Jang, Hee-Young;Suh, Sang-Uk
    • Korean Journal of Soil Science and Fertilizer
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    • v.48 no.5
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    • pp.477-484
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    • 2015
  • Environmental effect of water-saving irrigation on the emissions of greenhouse gases (GHGs) has not been well investigated. The objective of this study was to measure the effect of water-saving irrigation on GHGs as well as water use and rice production yield in paddy field condition in Korea. Four experimental runoff plots of 4x35 m in size were prepared at an existing paddy field. GHGs emission was measured during the 2012~2013 growing seasons while a Japonica rice variety was cultivated. Four different water management methods, 1) Continuous Flooding (CF), 2) Intermittent Drainage (ID), 3) Water Saving (WS), and 4) CF+WS, were used during a rice growing season to compare the effects of water management methods on GHGs emission. CF method is flooding all the time, ID method makes paddy water drained 40 days after transplanting for about two weeks, WS method maintains 2~3 cm water-level, which should be refilled when the water-level decreased to about 0 cm, and CF+WS method combines CF method before 30 days after transplanting (DAT) and WS method after 30 DAT. Regardless of water management methods, paddy field water was drained about 30 days before harvest. Amount of GHGs emission from WS plot was reduced by 69.3% compared to that from CF plot and by 59.0% compared to that from ID plot. Amount of GHGs emission from CF+WS plot was reduced by 60.7% compared to that from CF plot and by 47.5% compared to that from ID plot. Weed occurrence in CF+WS plots was reduced to 62.2% in comparison with the WS plot, implying that CF+WS plot showed the best effect to mitigation of the greenhouse gas emission in the atmosphere.

Energy saving methods & examples for eco-friendly sewage treatment plants (친환경 하수처리장을 위한 에너지 절감 방법 및 사례)

  • Han, Chang-Dong;Lim, Dong-Hee;Yu, Jae-Hong;Hwang, In-Gwang;Kim, Dong-Jin
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.1366-1367
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    • 2011
  • 저탄소 녹생성장의 국가정책에 부응하고 친환경 하수처리장 운영관리 및 에너지 자립률 향상을 위해 신재생에너지 설비 사용과 고효율 전기설비를 적용하여 안정적 하수처리장 운영을 하고자 함.

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Effects of Post-Harvest Bulk Management System Using Rice Processing Complex on Labor Saving and Quality of Barley (보리 산물처리에 의한 품질변화와 생력효과)

  • 이춘우;윤의병;구본철;백성범;손영구;서세정;남중현;김완석
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.47 no.6
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    • pp.475-478
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    • 2002
  • Post-harvest treatment for barley production requires many steps including drying, cleaning, and packing, and these steps be needed many labor input. Rice processing complex (RPC) is useful for post harvest management system in rice production. However, it is rare to be used for barley production. This study was conducted to explore the variations of quality and labor saving between conventional method and bulk-management system in post-harvest using RPC. The sorting rate was not different between manual method and bulk management. The hardness of non-polished grain was ranged 10,175-10,329 g/$3.14mm^2$, and that for non-polished grain was higher than that for polished grain, but there was not different between drying method. There was not be showed the hunter's value such as L, a and b according to drying method. Cooking characters such as water absorption ratio, swelling ratio, and water soluble extracts by circulated or continued dryer was higher than manual drying using solar heat. Labor input per ha for each cultivation process in bulk-management of barley using rice processing complex was 21 hours, compared to 46 hr/ha in the conventional method, labor input was greatly saved by up to 54.3% in the post-harvest bulk management system.

Membrane Processes for Energy Saving in Japan

  • Nakao, Shin-ichi
    • Proceedings of the Membrane Society of Korea Conference
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    • 1994.06a
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    • pp.45-58
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    • 1994
  • Over the last 20 years, membrane separation processes, such as reverse osmosis, ultrafiltration and microfiltration, have been widely adopted by different industries. Commercial uses of membrane have displaced conventional separation processes, such as distillation, evaporation, precoat filter and so on. Membrane separation processes are often more capital and energy efficient when compared with conventional separation processes. Membrane devices and systems are almost always compact and modular. These are the well-known advantages of membrane separation processes. The disadvantage of the membrane process is that the process does not have scale merit and thus the membrane process is suitable for the small and middle size applications. Energy saving is, of course, the biggest advantage of the membrane process, and in many industries the membrane processes are employed because of this reason. Membrane process has other big advantage. In many applications membrane processes provide much higher quality of product than conventional processes. The example is ultrapure water production by membrane processes in semiconductor industry. Conventional technologies never offer such good quality of pure water. If you can obtain both energy saving and higher quality of product at the same time by membrane processes, this is the best application of membrane processes. One example is the concentration of orange juice by membrane, which has already been commercialized in Japan. Comparing with the conventional vacuum evaporation process, juice concentrated by the membrane process has much better taste and flavor and the energy consumption in the membrane process is much less than the evaporation process. In this paper, first membrane separation technology will be classified and then Japanese membrane manufacturers and new modules and devices under development in Japan will be introduced. Fourth energy saving in membrane process will be discussed and finally practical applications of membrane processes in Japan will be shown.

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Strategy of Energy Saving and Thermal Environment Improvement for Intermittent Heating System in Apartment Buildings (공동주택 간헐난방시스템의 에너지 절감 및 열환경 개선방안 연구)

  • Ahn Byung-Cheon;Lee Tae-Won
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.17 no.1
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    • pp.88-93
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    • 2005
  • In this study, the operational characteristics on heating performance and energy consumption for intermittent hot water heating system in apartment buildings were research by simulation. The effects of apartment inlet hot water temperature and operation time per day on energy consumption and indoor thermal environment are investigated. The strategy of energy saving and thermal environment improvement is suggested in comparison with the existing ones.

A study on the optimal design for heat insulation of hot water piping systems using a dynamic programming (동적계획법을 이용한 고온수배관의 최적보온설계에 관한 연구)

  • 유희한;하주식
    • Journal of Advanced Marine Engineering and Technology
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    • v.11 no.1
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    • pp.39-52
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    • 1987
  • Recently, the design problem of heat insulation have been reappraised in the aspect of energy saving due to the rising trend of energy cost. For example, that design problem is increasingly requsted in the fields of accommodation air conditioning systems, hot water supply systems, cargo handling systems, district heating or cooling systems. The rational design of heat insulation of piping systems can not only improve the overall efficiency of energy transfer but also give energy saving. In this paper, the heat insulation problem of district heating systems is therefore modeled as the multi-stage decision processes, suitable for dynamic programming technique. And take the object function as the sum of heat insulation material cost involved construction cost and heat loss cost, and propose the design method to minimize the object function for overall piping systems by dynamic programing. Effectiveness of design method presented here is proved by a computer simulation.

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Energy Simulation for Energy Saving Opportunities

  • Lee, E.J.;J.H. Yoon;Y.H. Kang;H.S. Jeon
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 1995.05a
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    • pp.88-93
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    • 1995
  • The purpose of this study is to introduce the energy simulation program BLDSYM, verify the approach. and demonstrate the energy saving opportunities. A case study model for Hoover Middle School, OK USA has been introduced as a base case simulation. Air-side variable air volume (VAV) and water-side variable flow hydronic (VFH) system have been recommended, modeled and simulated to quantify the energy savings compared with the base system, which is typically constant air and water flow system. More than 30 % of energy savings could be obtained with the optimum variable flow system.

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A Study of Optimized Operation for CO2 Emission and Aircraft Fuel Reduced Operation Procedures (온실가스배출 감소와 연료절감을 위한 최적 운용절차 방안에 관한 연구)

  • Hwang, Jeong-Hyun;Lee, Tae-Gwang;Hwang, Sa-Sik
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.21 no.4
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    • pp.62-70
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    • 2013
  • As the aviation industry looks to the future, fuel saving and $CO_2$ emission reduction play a dominant role in meeting the business challenges presented by global financial uncertainty. The IATA and International Government effort to save fuels, and then save 4 billion gallons of fuel burned, while reducing $CO_2$ emissions by 34 million tons. The various reduction methods adapted airlines and airports. We focused on optimized flight operation procedures for saving fuel and reduction emission cases. IATA and Canada government research reports focused on four methods that Engine Core Washing, Portable Water Management, Single Engine Taxi, APU limit operation. Apply to domestic airlines fuel data, Engine Core washing was saving more than Twenty-four thousand tons $CO_2$ emissions.

Cost Effective Quasi-Resonant Soft Switching PWM High Frequency Inverter With Minimum Circuit Components for Consumer IH Cooker and Steamer

  • Sugimura, Hisayuki;Eid, Ahmad-M.;Nakaoka, M.;Lee, H.W.
    • Proceedings of the KIEE Conference
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    • 2005.04a
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    • pp.134-139
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    • 2005
  • This paper presents a cost effective quasi-resonant soft-switching PWM high frequency inverter with minimum circuit components. This inverter can achieve wider soft commutation, simpler power circuit configuration, smaller volumetric size, lower cost and wider power regulation range, higher-efficiency as compared with single ended quasi-resonant ZVS-PFM inverter and active voltage clamped quasi-resonant ZVS-PWM inverter. The operation principle of the proposed inverter is described on the basis of the simulation and experimental results, together with its operating performances in steady state. The operating performances of this unique proposed high frequency inverter based on ZVS and ZCS arms-related soft commutation principle is evaluated and discussed as compared with the active voltage-clamped ZVS-PWM inverter and a conventional single-ended ZVS-PFM inverter. The practical effectiveness of a novel type quasi-resonant soft-switching PWM high frequency inverter using IGBT is actually proved for consumer induction heated appliances as rice cooker, hot water producer, steamer and super heated steamer. The extended bidirectional circuit topology of quasi-resonant PWM high frequency inverter with minimum circuit components is demonstrated, which operate as the direct frequency changer.

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