• Title/Summary/Keyword: Electric heating

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Changes in Rural Health and Environmental Factors (2001-2010) A Comparison between Agricultural and Nonagricultural Groups (농촌 환경ㆍ건강 지표의 변화 추이(2001~2010년) -농촌 거주 농업종사자와 비농업종사자의 비교-)

  • Rhie, Seung Gyo;Hwang, Jeong-Im;Won, Hyang Rye
    • The Korean Journal of Community Living Science
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    • v.25 no.1
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    • pp.99-111
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    • 2014
  • To verify welfare needs, rural health and environmental factors were compared between agricultural and nonagricultural groups over the past 10 years. Based on a survey of rural life by the Rural Development Administration, whose sample included agricultural (72.8%) and nonagricultural (27.2%) groups, all factors were analyzed using SAS ( 9.3). For rural home heating, the use of oil boilers (77.2%-78.0%) decreased (53.0%-53.7%) over the same period, whereas that of electric boilers increased (21.9% and 13.5% for agricultural and nonagricultural groups, respectively). The joint water- supply increased, and the use of flush toilets (52.4% to 84.5% in the agricultural group and 64.6% to 81.4% in the nonagricultural group) and hot-water bathing was higher in the agricultural group (79% to 92.6%) than in the nonagricultural group (72.2% to 87.6%) at the p<0.001 level. Incineration accounted for the largest portion of household waste until 2006, when it was replaced by other treatment methods such as the pay-per-treatment option (44.4% and 68.3% in the agricultural and nonagricultural groups, respectively) (p<0.001). Garbage disposal in 2001 was mainly burial or animal feed, but separate collection increased in 2010 (42.2% and 64.3% in the agricultural and nonagricultural groups, respectively) (p<0.001). The self-perception of health was lower in the agricultural group than in the nonagricultural group (2.96 to 2.74 on a five-point scale in the agricultural group and 3.07 to 2.98 in the nonagricultural group). Drinking decreased less in the agricultural group (criteria: one point once a week,; 1.48 to 1.20) than in the nonagricultural group (1.13 to 0.80) at p<0.001, and a similar pattern was found for smoking (p<0.001). Health screening decreased in the last 10 years (scoring based one point/1-2 times per year,: 0.94 to 0.64 in the agricultural group and 1.08 to 0.69 in the nonagricultural group;p<0.01). These results indicate that various health and environmental factors were less favorable to farmers except for bathing in comparison to nonagricultural living in the same area. This suggests that people in agriculture are less likely to live and work in favorable environments than those outside the sector and thus indicates a need for more attention to the national health welfare system for farmers for systematic realization.

Physico-mechanical Properties and Optimum Manufacturing Conditions of Bi-Sn Metal Alloy Impregnated Wood Composites (Bi-Sn 용융합금주입 목재복합체의 최적제조조건 및 물리·기계적 특성)

  • Park, Kye-Shin;Lee, Hwa-Hyoung;Kang, Seog Goo
    • Journal of the Korean Wood Science and Technology
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    • v.42 no.6
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    • pp.691-699
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    • 2014
  • In order to improve the dimensional stability and durability of wood, this study attempted to impregnate bismuth (Bi) - tin (Sn) alloy metal with low melting temperature into solid woods of three species such as radiata pine, red oak and white oak, and investigated to determine an optimum condition of manufacturing the metal alloy-wood composites with natural wood grains. These Bi-Sn alloys were chosen for this study because they were harmless to human and melting at low temperatures. The composites resulted in high dimensional stability and low thickness swelling, and also showed much improved performance such as high bending strength, high hardness, high electric conductivity, and high thermal conductivity as floor materials. A proper impregnating condition of all specimens was determined as 10 minutes of the preliminary vacuum time, and $185^{\circ}C$ of the heating temperature. The proper processing condition for radiata pine wood was 2.5 minutes of the pressuring time at the pressure of $10kgf/cm^2$. For red oak wood, 10 minutes of the pressuring time at the pressure of $30kgf/cm^2$ were the proper condition. The proper manufacture conditions for white oak wood was determined as 10 minutes of the pressuring time at the pressure of $50kgf/cm^2$.

Implementation of the Urban Development Projects in Ulaanbaatar (도시개발 여건을 고려한 울란바타르 건설사업 참여방안)

  • Jeong, Yeun-Woo;Seong, Jang-Hwan
    • Land and Housing Review
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    • v.3 no.4
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    • pp.357-367
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    • 2012
  • The efficient business scheme were suggested with the consideration of the local development condition at Ulaanbaatar. Major findings of the study were presented as follows. First, high level of education and the underground resources are presented as the merits of Mongolia. On the other side, the defects are limited domestic demands of 2.6 millions of population and the insufficiency of the infrastructure. The improvement of the infrastructures like roads, water & sewage, electric power, and heating is urgent while the development pressure of Ulaanbaatar is expected to be high due to the continuous inflow of population. Secondly, the Mongolian land system consists of the right of ownership, lease and use, therefore there are some differences among the right of land. Thirdly, definite business scheme to sell land in lots and to sell buildings in lots are suggested which are actual methods to participate in the development project in Ulaanbaatar. Moreover, enhancing the possibility to sell the lands, fixing the proper sale price to secure the profit, finding the proper buyer for the profitable lands, investing of quota and guaranteeing of granting the principal and interest by the Mongolian government, etc. are presented as consideration when participate in projects.

Recognition and Application on the Curriculum of High School Home Economics by Teachers and Students -Centering on the Unit of Cooking Practice- (고등학교 가정과 교사와 학생의 가정과 교과내용에 관한 인식 및 활용 -조리실습단원을 중심으로-)

  • 주명자;임양순
    • Journal of Korean Home Economics Education Association
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    • v.3 no.1
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    • pp.1-13
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    • 1991
  • The purpose of this study is to find out problems through looking into the actual condition of management and the extent of application in cooking practice in High School Home Economics Education, and as a practical subject, to present some basic materials to contribute to accomplishing the object of High School Home Economics Education through trying to find a direction to enhance educational value. The contents of this study are these : to study with a theoretical background character, object, and contents of Home Economics referring to related books and to investigate the actual condition of management, the extent of application to life of cooking practice unit, and standard of recognition of students and teachers about this subject and to find out rational and efficient method of management. 552 girl students and 72 home economics teachers in cities and counties in Kangwon-do were asked to answer the answer-sheet prepared. The result of this study is summerized as follows. 1. Most of the respondent regard the characters and objects of Home Economics as a matter of basic education, education for life, and education for the wholeman, but they neglect the aspect of education for a course of this subject. 2. Among the contents of Home Economics, students are much interested in the Unit of preparing table, especially in cooking. Most of the teachers teach the cooking unit with only explanation without practice because of the lack of material and human resources. 3. Students have desire to do cooking practice, but the extent of application of their real life appears to be low. 4. It appears to be necessary that boy students as well as girl students should learn Home Economics as an education for preparation for managing housework. 5. Home Economics teachers are mostly satisfied with their teaching profession. But teachers who have been teaching for 3 or 5 years appear not to be satisfied with it. 6. Although Home Economics teachers can teach Cooking practice Unit with confidence, they usually do it with theory rater than with practice, and they evaluate it after practicing, but most of them do not add the result to the student’s grade. 7. They use most of the cookers fixed on the standard list of High School Cooking Practice appliances, but they seldom use electric heating cookers.

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Development of Eco-friendly Combustion Process for Waste 2,4,6-trinitrotoluene (폐 2,4,6-trinitrotoluene의 환경 친화적 연소처리공정 개발)

  • Kim, Tae Ho;An, Il Ho;Kim, Jong Min
    • Clean Technology
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    • v.27 no.3
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    • pp.247-254
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    • 2021
  • In this study, an eco-friendly combustion process of waste 2,4,6-trinitrotoluene (TNT: 2,4,6-trinitrotoluene) was developed, and fundamental data for the quantity of the organic matter in the final combustion residues is presented. Because complete combustion of TNT is not possible theoretically, the combustion process was optimized to reduce organic matter content in the combustion residue by performing measures such as heating time changes, addition of propellant material, and after treatment using a high-temp electrical furnace. From the results, it was confirmed that the organic matter content in the residue could be decreased to 7 ~ 10% with each method. The quantity of the organic matter could be minimized by optimizing the combustion conditions of the process. With only a combustion time increase, the amount of organic matter in the combustion residues was measured at about 9 wt%. The environmental friendliness of the final exhaust gas was also confirmed by real time gas component analyses. In addition, the organic contents could be reduced by a further 2 wt% by applying an additional heat treatment using an external electric furnace after the first incineration treatment. In the combustion process of propellant added waste TNT, it was found that various TNT wastes could be treated using the same eco-friendly protocols because the organic content in the residue decreased in accordance with the amount of propellant. The amount of the organic matter content produced by all these methods fulfilled the requirements under the Waste Management Act.

Forecasting daily peak load by time series model with temperature and special days effect (기온과 특수일 효과를 고려하여 시계열 모형을 활용한 일별 최대 전력 수요 예측 연구)

  • Lee, Jin Young;Kim, Sahm
    • The Korean Journal of Applied Statistics
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    • v.32 no.1
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    • pp.161-171
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    • 2019
  • Varied methods have been researched continuously because the past as the daily maximum electricity demand expectation has been a crucial task in the nation's electrical supply and demand. Forecasting the daily peak electricity demand accurately can prepare the daily operating program about the generating unit, and contribute the reduction of the consumption of the unnecessary energy source through efficient operating facilities. This method also has the advantage that can prepare anticipatively in the reserve margin reduced problem due to the power consumption superabundant by heating and air conditioning that can estimate the daily peak load. This paper researched a model that can forecast the next day's daily peak load when considering the influence of temperature and weekday, weekend, and holidays in the Seasonal ARIMA, TBATS, Seasonal Reg-ARIMA, and NNETAR model. The results of the forecasting performance test on the model of this paper for a Seasonal Reg-ARIMA model and NNETAR model that can consider the day of the week, and temperature showed better forecasting performance than a model that cannot consider these factors. The forecasting performance of the NNETAR model that utilized the artificial neural network was most outstanding.

Flexural Behavior of Concrete Beams Reinforced with Fe based Shape Memory Alloy Bar (철계-형상기억합금 바로 제작된 콘크리트 보의 휨 거동)

  • Hong, Ki-Nam;Yeon, Yeong-Mo;Ji, Sang-Won
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.24 no.6
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    • pp.67-76
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    • 2020
  • This paper reports an experimental study to evaluate the flexural behavior of concrete beams reinforced using Fe based shape memory alloy (Fe-SMA) bars. For the experiment, a concrete beam of 200mm×300mm×2,200mm was produced, and a 4% pre-strained Fe-SMA bar was used as a tensile reinforcement. As experimental variables, type of tensile reinforcement (SD400, Fe-SMA), reinforcement ratio (0.2, 0.39, 0.59, 0.78), activation of Fe-SMA (activation, non-activation), and joint method of Fe-SMA bar (Continuous, welding, coupler) were considered. The electric resistance heating method was used to activate the Fe-SMA bar, and a current of 5A/㎟ was supplied until the specimen reached 160℃. After the upward displacement of the specimen due to the camber effect was stabilized, a three-point flexural loading experiment was performed using an actuator of 2,000 kN capacity. As a result of the experiment, it was found that the upward displacement occurred due to the camber effect as the Fe-SMA bar was activated. The specimen that activated the Fe-SMA bar had an initial crack at a higher load than the specimen that did not activate it. However, as with general prestressed concrete, the effect of the prestress by Fe-SMA activation on the ultimate state of the beam was insignificant.

A study on the correction of the connection part of the underground facility 3D model and the correction of irregularities (지하시설물 3차원 모델 연결부 보정 및 요철보정에 관한 연구)

  • Kim, Sung Su;Han, Kyu Won;Heo, Sung Seo;Han, Sang Hoon
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.39 no.6
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    • pp.429-435
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    • 2021
  • The integrated underground space map shows the underground facility(water supply, sewage, gas, electric power, communication, heating), underground structures (subway, underpass, underground walkway, underground parking lot, underground shopping mall, common ward), ground(drilling, coffin, geology) refers to a map constructed so that a total of 15 types of underground information can be checked at a glance on a three-dimensional basis. The purpose of this study is to develop a technology to correct the problem of curved surface processing and the unevenness of underground facility pipelines that occur in converting 2D underground facility data into 3D-based underground space integrated map(3D underground facility model). do it with. To this end, we first investigated and reviewed the domestic and foreign status of technologies that generate data on underground facilities based on three dimensions, and developed a surface correction algorithm and an unevenness correction algorithm to solve practical problems. Algorithms to verify the developed algorithm This applied correction program was developed. Based on the above process, the three-dimensional model of the underground facility could be produced identically to reality. This study is judged to have significance as a basic study to improve the utilization of the underground spatial integration map.

Reduction effects of isoprothiolane during rice washing and cooking (쌀 세척 및 취반 방법에 따른 isoprothiolane의 감소 효과)

  • Myungheon Kim;Mihyun Cho;So Eun An;Moo-Hyeog Im
    • Food Science and Preservation
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    • v.30 no.3
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    • pp.472-482
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    • 2023
  • This study used gas chromatography combined with the microelectron capture detection method to determine the most effective washing and cooking methods for removing isoprothiolane from rice. The initial isoprothiolane concentrations in brown and polished rice, before washing, were 17.03 mg/kg and 1.67 mg/kg, respectively. Residual concentrations declined with more washing cycles (19.3-59.3% for brown rice; 43.1-66.5% for polished rice); and by increasing the temperature of the washing water from 5℃ to 40℃ (56.6-63.1% for brown rice; 67.1-74.9% for polished rice). Hand-washing samples using gentle stirring or harsh rubbing reduced pesticide concentrations by 63.1-71.6% for brown rice, versus 75.4-87.4% for polished rice. Reduction in isoprothiolane concentrations varied based on the rice cooker type and whether the rice was pre-soaked. Immediate cooking using an electric- or pressure-cooker showed 78.5% and 78.4% reduction in brown rice, compared with 94.0% and 94.0% for polished rice, respectively. Pre-cooking immersion for 30 min showed similar reductions of 83.4% and 83.4% in brown rice, versus 95.8% and 95.8% in polished rice. The results of this study suggest that the most effective method for removing residual isoprothiolane from both brown rice and polished rice was to wash six times (with vigorous rubbing during the 2nd and 3rd washing) in 7-fold water at 40℃, followed by immersion for 30 min before cooking. Regardless of the type of rice cooker, heating is sufficient to remove an average of 83.4% and 95.8% of isoprothiolane from brown rice and polished rice, respectively.

Quality Changes and Pasteurization Effects of Citrus Fruit Juice by High Voltage Pulsed Electric Fields (PEF) treatment (고전압 펄스 전기장 처리에 의한 감귤주스의 품질변화)

  • Kim, Kyung-Tack;Kim, Sung-Soo;Hong, Hee-Do;Ha, Sang-Do;Lee, Young-Chun
    • Korean Journal of Food Science and Technology
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    • v.35 no.4
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    • pp.635-641
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    • 2003
  • A non-thermal pasteurization technology, high Pulsed Electric Field (PEF) has been thought to be a new alternative processing technology instead of heating. The objective of this study was to examine and compare the effect of PEF and High Temperature Short Time (HTST) treatments on the physicochemical, microbiological and sensory characteristics of citrus juices. Total sugar and titratable acidity values of fresh citrus juice and two treatments were not significantly different each other at p<0.05. The concentration of vitamin C in fresh citrus juice $(31.2{\pm}0.59\;mg%)$ was not significantly different with the value of PEF treatment $(29.4{\pm}0.75\;mg%)$ but was significantly higher than the value of HTST treatment $(27.4{\pm}0.75\;mg%)$. The color values (L, a, and b) in PEF treatment were significantly lower than the fresh citrus juice, but were higher than the values of HTST treatment. Both total bacterial cell counts $(6.65\;{\pm}\;0.08\;log_{10}(cfu/mL))$ and yeast counts $(7.79{\pm}0.07\;log_{10}(cfu/mL))$ in fresh citrus juice were significantly reduced by PEF $(1.39{\pm}0.14,\;2.42{\pm}0.1\;log_{10}(cfu/mL))$ as well as HTST treatment (0, 0). PE activity of fresh citrus juice $(1.3{\pm}0.12\;units/mL)$ was significantly reduced by PEF treatment $(0.11{\pm}0.01\;units/mL)$ and was totally inactivated by HTST treatment. Sensory evaluation scores in flavor, taste and overall acceptability between the fresh and PEF treated citrus juices $(7.2{\sim}7.5)$ were not significantly different but the values of HTST treatment $(5.1{\sim}5.8)$ were lower than others. Consequently, PEF treatment is thought to be a good alternative pasteurization method for fresh citrus juice to HTST treatment due to its strong pasteurization effect, reduced destruction of nutrients and good sensory characteristics.