• Title/Summary/Keyword: 에너지 정의

Search Result 2,864, Processing Time 0.03 seconds

Interview - "Intergenerational connection, the era of disappeared issues - It is time to look at the changing society while putting together differences and small voices" (인터뷰 - "세대 간 연결, 이슈가 사라진 시대… 다름과 작은 소리를 축적하며 변화하는 사회를 바라보아야")

  • Jang, Yeong-Ho
    • Korean Architects
    • /
    • s.600
    • /
    • pp.34-41
    • /
    • 2019
  • 대통령 소속 국가건축정책위원회, 건축정책기본계획, 건축도시공간연구소, 공공건축가. 지금 우리 건축계를 정의하는 중요한 개념들이다. 이 모두 2007년 제정된 건축기본법에 근거한 내용으로서 당시 건설기술 건축문화선진화위원회, 건설교통부, 문화관광부의 '건축문화 선진화전략' 핵심과제였다. 그러나 '건축기본법'이 있어야 한다고 처음 주장한 사람은 김광현 서울대학교 건축학과 명예교수였다. 그가 연구책임자로서 건축기본법의 바탕을 만들었으며, 오늘의 건축계를 정의하는 건축기본법의 틀과 개념 그리고 용어의 설정도 거의 그의 구상에서 나왔다. 대한건축사협회(한명수 명예회장)와 건설기술 건축문화선진화위원회(김진애 위원장)가 이 법 제정을 위해 큰 힘을 기울였다면, 그는 이론적 기틀을 확립한 인물이다. 그는 학계에 있었지만 설계대가 제값 받기에 유독 관심이 많았다. 이유는 학생들이 사회에 나가 전문가로서 좋은 일을 할 수 있는 최대의 근거는 제대로 된 설계대가에 있다는 그의 지론 때문이었다. "학생들을 가르치는 최고의 목표는 그들이 사회에 나가 좋은 대접을 받게 하는 겁니다. 건축계에서 해야 할 가장 중요한 게 뭐냐고 지금 또 묻는다면 단언컨대 나는 제대로 된 '설계대가'라고 말할 겁니다." 김광현 명예교수는 과거 '공공발주사업에 대한 건축사의 업무범위와 대가기준'에서 '친환경건축물, 에너지효율등급' 등 추가업무에 대한 대가를 제대로 받을 수 있게 하자고 주장하고 이를 연구한 책임자이기도 했다. 그는 지금 젊은 건축사 건축교육 저변확대를 위한 '공동건축학교'를 설립해 활발히 운영 중이다. 월간 "건축사"가 국내 건축계 발전을 위해 힘써오다가 작년 2월 정년퇴임한 김광현 서울대학교 건축학과 명예교수를 3월 18일 그의 대학로 연구실에서 만났다. 그는 지난날을 회고하며 건축에 얽힌 이야기와 현재 하고 있는 일, 그리고 구상 중인 향후계획까지 다양한 이야기를 전했다.

  • PDF

Analysis on the Cooling Effect of Applying Temperature Discoloration Paint to a Roof Surface (온도 변색 도료의 지붕 적용 및 냉방효과 분석)

  • Baek, Sanghoon
    • Land and Housing Review
    • /
    • v.13 no.4
    • /
    • pp.115-123
    • /
    • 2022
  • This study aims to introduce a temperature discoloration roof system and its cooling effect in the summer. Temperature discoloration paints can reverse their colors based on temperature changes. If these paints on the roof surface could color-shift between white in the summer and black in the winter, the indoor cooling and heating loads can be affected by the changes in reflection and absorption of solar radiation. Focusing on the summer period, the study analyzed the cooling effect of applying temperature discoloration paint that color-shifts from white to black on the roof surface of a small experimental building module and compared it to commonly used gray and green roof colors. Results of the experiment showed that the surface temperature of the roof with temperature discoloration paint was lower than the gray and green color roofs by a maximum of 10℃. Furthermore, the indoor temperature of the experimental module with the temperature discoloration roof was lower than the gray and green roofs by approximately 3℃. Findings of the study indicate that the application of temperature discoloration paint to the roof can reduce indoor cooling loads.

Stiffness Degradation Induced by Seismic Loading on a RC Shear Wall (지진하중에 의한 철근콘크리트 전단벽의 강성 저하에 관한 연구)

  • Lee, Yun
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.26 no.3
    • /
    • pp.48-54
    • /
    • 2022
  • This research describes a quantitative procedure used to estimate the effect of concrete cracking on stiffness degradation of concrete shear walls and provides analytical references for the seismic design of concrete shear walls. As preliminary research on the seismic response of concrete shear walls, nonlinear transient analysis was performed with commercial FE software. The study presents the nonlinear time history analysis results in terms of concrete damage and cracking behavior induced by seismic input motions. By varying the input motions, concrete strength and shear wall thickness, the seismic responses of a shear wall were examined with nonlinear time history analysis, and the progressive cracking behavior and corresponding hysteresis loop were described. Based on the analysis results, frequency and stiffness degradation of the shear wall from progressive concrete damage and cracking were captured with respect to the seismic levels. The results of this study suggest that stiffness degradation from concrete cracking should be appropriately considered when determining the seismic capacity of RC shear wall structures.

Estimation of Soil Surface Temperature by Heat Flux in Soil (Heat flux를 이용한 토양 표면 온도 예측)

  • Hur, Seung-Oh;Kim, Won-Tae;Jung, Kang-Ho;Ha, Sang-Keon
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.37 no.3
    • /
    • pp.131-135
    • /
    • 2004
  • This study was carried out for the analysis of temperature characteristics on soil surface using soil heat flux which is one of the important parameters forming soil temperature. Soil surface temperature was estimated by using the soil temperature measured at 10 cm soil depth and the soil heat flux measured by flux plate at 5 cm soil depth. There was time lag of two hours between soil temperature and soil heat flux. Temperature changes over time showed a positive correlation with soil heat flux. Soil surface temperature was estimated by the equation using variable separation method for soil surface temperature. Arithmetic mean using temperatures measured at soil surface and 10 cm depth, and soil temperature measured at 5 cm depth were compared for accuracy of the value. To validate the regression model through this comparison, F-validation was used. Usefulness of deductive regression model was admitted because intended F-value was smaller than 0.001 and the determination coefficient was 0.968. It can be concluded that the estimated surface soil temperatures obtained by variable separation method were almost equal to the measured surface soil temperature.

Evaluation on Feed-Nutritional Change of Food Waste According to Different Processing Methods and Trouble-shooting Strategy (음식물쓰레기의 가공처리방법별 사료영양소 함량 변화 평가 및 문제점 개선 방안)

  • Jee, K.S.;Baik, Y.H.;Kwak, W.S.
    • Journal of Animal Science and Technology
    • /
    • v.47 no.4
    • /
    • pp.513-524
    • /
    • 2005
  • This study was conducted to introduce recycling procedures of food waste(FW) as feed according to the dehydration, semi-dehydration fermentation and liquid fermentation methods through the on-site survey of companies related, to trace physico-chemical components and nutritional losses depending upon the processing stage for each method and finally to suggest more desirable methodology for the efficient utilization of FW as animal feed. For the dehydration method, dewatering of FW alone reduced(P<0.05) moisture(approximately 10%) and ether extract contents and increased(P<0.05) fiber contents. Dewatering and subsequent dehydration of FW decreased(P<0.05) contents of ether extract, limiting amino acids such as lysine, methionine and histidine, pepsin digestibility of protein by half, and NaCl content by 40%, increased(P<0.05) contents of fiber, crude ash, Ca and P, and did not alter(P>0.05) pH. The semi-dehydration fermentation method of FW did not affect(P>0.05) the chemical components, pepsin digestibility of protein, pH and NaCl content. For the liquid fermentation method, pasteurization and fermentation of FW decreased(P<0.05) contents of dry matter, ether extract, crude fiber, lysine and NaCl; however, it did not affect(P>0.05) other chemical components, pepsin digestibility of protein and pH. Among the processing methods, nutrient losses were highest for the dehydration method(25% of metabolizable energy loss, 12% of organic matter loss) and little for the semi-dehydration and liquid fermentation methods. The on-site survey of companies related revealed that the existence of foreign materials in FW products were problematic for all the three companies surveyed, thus it was necessary to develop a more efficient screener. Before feeding FW-containing diets to pigs, high quality of protein and energy feedstuffs needed to be fortified for the dehydration method. For the semi-dehydration fermentation method, the scientific diet formulation technology was required at the initial mixing stage. For the liquid fermentation method, possibly most energetic and proteinaceous feeds needed to be supplemented for the normal animal growth.

Evaluation of Rapeseed Seedling Quality According to Varieties and Seedling Ages for Spring Cultivation Transplanting (유채 봄 재배 기계이식을 위한 품종별 육묘 일수에 따른 묘소질 평가)

  • An, Da-Hee;Cha, Young-Lok;Kim, Kwang-Soo;Shin, Woon-Chul;Lee, Ji-Eun
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.66 no.3
    • /
    • pp.256-264
    • /
    • 2021
  • Rapeseed (Brassica napus L.) is generally sown in late autumn and harvested in early summer in Korea, however, spring cultivation has also been attempted in some areas because frequent climate changes induce reducing productivity. Therefore, there is a need for a transplanting technology that is relatively easy to control of cropping season according to changes in cultivation conditions. In this study, to find out the optimal characteristics of seedlings for machine transplanting of spring cultivation, seedling morphological characteristics were investigated according to the seedling age of three varieties for 2020 and 2021. The hypocotyl length was less than 2 cm in both years and the 40-day-old seedling was the shortest among all seedling ages. The number and size of leaf were increased with longer seedling age in both years. To evaluate seedling quality, total seedling length, seedling weight, and impact resistance were measured before transplanting. Total seedling length was the longest in 40-day-old seedlings and the shortest in 25-day-old seedlings in both years. In the case of seedling weight, no significant differences were observed depending on the seedling age and the impact resistance increased with increasing seedling age. Finally, 'Jungmo7001', 'Naehan', and 'Tamla' showed a high transplanting rate in seedlings grown for more than 30 days, 35 days, and 40 days, respectively, in the field using a general transplanter. These results suggest that the proper seedling age for transplanting is limited depending on the rapeseed varieties. The suitable seedling cultivation method can be selected for different cultivation environments.

THE RELATIONSHIP BETWEEN PARTICLE INJECTION RATE OBSERVED AT GEOSYNCHRONOUS ORBIT AND DST INDEX DURING GEOMAGNETIC STORMS (자기폭풍 기간 중 정지궤도 공간에서의 입자 유입률과 Dst 지수 사이의 상관관계)

  • 문가희;안병호
    • Journal of Astronomy and Space Sciences
    • /
    • v.20 no.2
    • /
    • pp.109-122
    • /
    • 2003
  • To examine the causal relationship between geomagnetic storm and substorm, we investigate the correlation between dispersionless particle injection rate of proton flux observed from geosynchronous satellites, which is known to be a typical indicator of the substorm expansion activity, and Dst index during magnetic storms. We utilize geomagnetic storms occurred during the period of 1996 ~ 2000 and categorize them into three classes in terms of the minimum value of the Dst index ($Dst_{min}$); intense ($-200nT{$\leq$}Dst_{min}{$\leq$}-100nT$), moderate($-100nT{\leq}Dst_{min}{\leq}-50nT$), and small ($-50nT{\leq}Dst_{min}{\leq}-30nT$) -30nT)storms. We use the proton flux of the energy range from 50 keV to 670 keV, the major constituents of the ring current particles, observed from the LANL geosynchronous satellites located within the local time sector from 18:00 MLT to 04:00 MLT. We also examine the flux ratio ($f_{max}/f_{ave}$) to estimate particle energy injection rate into the inner magnetosphere, with $f_{ave}$ and $f_{max}$ being the flux levels during quiet and onset levels, respectively. The total energy injection rate into the inner magnetosphere can not be estimated from particle measurements by one or two satellites. However, the total energy injection rate should be at least proportional to the flux ratio and the injection frequency. Thus we propose a quantity, “total energy injection parameter (TEIP)”, defined by the product of the flux ratio and the injection frequency as an indicator of the injected energy into the inner magnetosphere. To investigate the phase dependence of the substorm contribution to the development of magnetic storm, we examine the correlations during the two intervals, main and recovery phase of storm separately. Several interesting tendencies are noted particularly during the main phase of storm. First, the average particle injection frequency tends to increase with the storm size with the correlation coefficient being 0.83. Second, the flux ratio ($f_{max}/f_{ave}$) tends to be higher during large storms. The correlation coefficient between $Dst_{min}$ and the flux ratio is generally high, for example, 0.74 for the 75~113 keV energy channel. Third, it is also worth mentioning that there is a high correlation between the TEIP and $Dst_{min}$ with the highest coefficient (0.80) being recorded for the energy channel of 75~113 keV, the typical particle energies of the ring current belt. Fourth, the particle injection during the recovery phase tends to make the storms longer. It is particularly the case for intense storms. These characteristics observed during the main phase of the magnetic storm indicate that substorm expansion activity is closely associated with the development of mangetic storm.

Environmental Impact Assessment of Rapeseed Cultivation by Life Cycle Assessment (전과정평가를 이용한 유채재배의 환경영향 평가)

  • Hong, Seung-Gil;Nam, Jae-Jak;Shin, Joung-Du;Ok, Yong-Sik;Choi, Bong-Su;Yang, Jae-E.;Kim, Jeong-Gyu;Lee, Sung-Eun
    • Korean Journal of Environmental Agriculture
    • /
    • v.30 no.1
    • /
    • pp.24-30
    • /
    • 2011
  • BACKGROUND: High input to the arable land is contributed to increasing productivity with causing the global environmental problems at the same time. Rapeseed cultivation has been forced to reassess its positive point for utilization of winter fallow field. The Objective of this study was performed to assess the environmental impact of rapeseed cultivation with double-cropping system in paddy rice on Yeonggwang district using life cycle assessment technique. METHODS AND RESULTS: For assessing each stage of rapeseed cultivation, it was collected raw data for input materials as fertilizer and pesticide and energy consumption rate by analyzing the type of agricultural machinery and working hours by 1 ton rapeseed as functional unit. Environmental impacts were evaluated by using Eco-indicator 95 method for 8 impact categories. It was estimated that 216 kg $CO_2$-eq. for greenhouse gas, 3.98E-05 kg CFC-11-eq. for ozone lazer depletion, 1.78 kg SO2-eq. for acidification, 0.28 kg $PO_4$-eq. for eutrophication, 5.23E-03 kg Pb-eq. for heavy metals, 2.51E-05 kg B(a)p-eq. for carcinogens, 1.24 kg SPM-eq. for smog and 6,460 MJ LHV for energy resource are potentially emitted to produce 1 ton rapeseed during its whole cultivation period, respectively. It was considered that 90% of these potential came from chemical fertilizer. For the sensitivity analysis, by increasing the productivity of rapeseed by 1 ton per ha, potential environmental loading was reduced at 22%. CONCLUSION(s): Fertilization affected most dominantly to the environmental burden, originated from the preuse stage, i.e. fertilizer manufacturing and transporting. It should be included and assessed an indirect emission, which is not directly emitted from agricultural activities. Recycling resource in agriculture with reducing chemical fertilizer and breeding the high productive variety might be contribute to reduce the environmental loading for the rapeseed cultivation.

Effects of Varying the Concentration of Energy Yielding Nutrients on Nitrogen Balance and Body Composition of the Growing Rats (열량 영앙소의 수준이 흰쥐의 단백질 평형과 체조성에 미치는 영향)

  • Chang, Y.K.;Han, I.K.
    • Journal of Nutrition and Health
    • /
    • v.13 no.3
    • /
    • pp.117-125
    • /
    • 1980
  • In order to investigate the utilization efficiency of dietary protein in the rat body and effects of dietary fat on its protein metabolism, 51 Sprague-Dawly rats of 6 weeks old weighing approximate)y 106g were subjected to feeding trials for 4 weeks and then subsequently to metabolic trials for 3 weeks using six different diets composed of three different levels of protein (10%, 20% and 30%) with low (20%) and high (40%) fat content for each protein level, total energy being fixed at 4000 Kcal/kg by addition of an appropriate amount of carbohydrate, and the following results were obtained. 1) The body weight gain increased in the low fat diets with increasing protein level whereas it decreased in the high fat diets. Food efficiency also increased in the low fat diets with increasing protein level, but no do deffinitive trend was observed in the high fat diets. The protein efficiency was generally higher at low protein level and tended to decrease as the protein level increased, regardless of the amount of fat intake. 2) As the protein level was increasing, digestibility of dry matters and carbohydrate were decreasing whereas that of protein was slightly increasing. On the other hand, digestibility of fat was always very high regardless of the amounts of dietary protein and fat. 3) The gross energy intake was affected both by protein and fat contents in the diets: The energy metabolism efficiency was decreasing with increasing protein level and at the same protein level the energy utilization was considerably higher in the low fat diets than in the high fat. 4) From the above-mentioned experimental results it may be concluded that the best formula of diet for growing rats is probably composed of 20% protein, 20% fat and 60% carbohydrate.

  • PDF

Studies on Energy Metabolism of Growing Chicken (닭의 에너지 대사(代謝)에 관(關)한 연구(硏究))

  • Kwon, Soon Ki;Oh, Hong Rock
    • Korean Journal of Agricultural Science
    • /
    • v.9 no.2
    • /
    • pp.540-545
    • /
    • 1982
  • An energy metabolism study was conducted with two commercial strains of meat-type chickens, Hubbard and Cobb, and two egg strains, Hy Line and Korean-bred Hanhyup 325. The heat production of growing chickens from each strain were measured by the use of an open-circuit gravimetric respiration calorimeter. The data obtained from this study were summarized as fallows. 1. The average body weight of 9-wk-old Hubbard broilers reared in battery cages was 2,570g/bird. The average body weights of 9-wk-old Hy Line chicks and Hanhyup 325 were 777 and 748g/bird, respectively. 2. At 3 weeks of age, the Hubbard broiler chicks consumed two times the feed consumed by Hy Line chicks (54.6g VS. 26.7g/bird/day). These values increased to 151g and 57.2g/bird/day, respectively, at 8 weeks of age, indicating that the difference in feed intake between meat and egg-type chicks tends to increase as they grow older. In terms of water consumption, the 5-wk-old Hubbard broiler chicks drank $226m{\ell}/bird/day$ as compared with $58m{\ell}$ by Hy Line chicks. These values increased to 282 and $70m{\ell}$, respectively, at 8 weeks of age. 3. The excreta outputs of Hubbard broilers and Hy Line chicks were 18.7 and 6.1g DM/bird/day at 4 weeks of age, and 41.5 and 10.0g DM/bird/day at 8 weeks of age, respectively. 4. The energy metabolizability of broiler chicks were 75.4~77.1% compared to 75.0~83.5% by egg-type chicks. 5. The respiratory quotient (RQ) was between 0.78 and 0.97. There seems to be no difference in RQ between meat and egg-type chicks. The RQ tended to decrease when feed intake was low and vice versa. 6. Both meat and egg-type chicks produced $83.1{\sim}123.1Kcal/kg^{\frac{3}{4}}B.W./day$. The considerably low value of $83Kcal/kg^{\frac{3}{4}}B.W./day$ was obtained when the chicks were off the feed under the stressful conditions. The high value of 123.1Kcal was obtained when the chicken chamber temperature rose to $27{\sim}34^{\circ}C$.

  • PDF