• Title/Summary/Keyword: energy composition

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Effects of Addition of Hydrogen and Water Vapor on Flame Structure and NOx Emission In $CH_4$-Air Diffusion Flame (메탄-공기 확산화염에서 수소와 수증기 첨가가 화염구조와 NOx 배출에 미치는 효과)

  • Park, Jeong;Keel, Sang-In;Yun, Jin-Han
    • Journal of Hydrogen and New Energy
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    • v.18 no.2
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    • pp.171-181
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    • 2007
  • Blending effects of hydrogen and water vapor on flame structure and NOx emission behavior are numerically studied with detailed chemistry in methane-air counterflow diffusion flames. The composition of fuel is systematically changed from pure methane and pure hydrogen to the blending fuels of methane-hydrogen-water vapor through the molar addition of $H_2O$. Flame structure is changed considerably for hydrogen-blending methane flames and hydrogen-blending methane flames diluted with water vapor in comparison to pure methane flame. These complicated changes of flame structures also affect NOx emission behavior considerably. The changes of thermal NO and Fenimore NO are analyzed for various combinations of the fuel composition. Importantly contributing reaction steps to thermal NO and Fenimore NO are addressed in pure methane, hydrogen-blending methane flames, and hydrogen-blending methane flames diluted with water vapor.

Thermodynamic Analysis of the Extraction Process and the Cold Energy Utilization of LNG (LNG추출과정과 냉열이용의 열역학적 해석)

  • Lee, G.S.;Chang, Y.S.;Ro, S.T.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.7 no.1
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    • pp.120-131
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    • 1995
  • Thermodynamic analysis of extraction process from the constant pressure LNG(Liquefied Natural Gas) vessel was performed in this study. LNG was assumed as a binary mixture of 90% methane and 10% ethane by mole fraction. The thermodynamic properties such as temperature, composition, specific volume and the amount of cold energy were predicted during extraction process. Pressure as a parameter ranges from 101.3kPa to 2000kPa. The result shows the peculiar phenomena for the LNG as a mixture. Both vapor and liquid extraction processes were investigated by a computer model. The property changes are negligible in the liquid extraction process. For the vapor extraction process, the temperature in the vessel increases rapidly and the extracted composition of methane decreases rapidly near the end of extracting process. Specific volume of vapor has the maximum and that of liquid has the minimum during the process. When pressure is increased, specific volume of vapor decreases and that of liquid increases. It was found that specific volume of vapor phase had a major effect on the heat absorption at constant pressure during vapor extraction process. If the pressure of the vessel increases, the total cold energy which can be utilized from LNG decreased.

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MICROSTRUCTURAL CHARACTERIZATION OF U-10WT.%ZR FUEL SLUGS CONTAINING RARE-EARTH ELEMENTS PREPARED BY MODIFIED INJECTION CASTING

  • SANG-HUN LEE;KI-HWAN KIM;SEOUNG-WOO KUK;JEONG-YONG PARK;JI-HOON CHOI
    • Archives of Metallurgy and Materials
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    • v.64 no.3
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    • pp.953-957
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    • 2019
  • U-10wt.%Zr metallic fuel slugs containing rare-earth (RE: a rare-earth alloy comprising 53% Nd, 25% Ce, 16% Pr and 6% La) elements for a sodium-cooled fast reactor were fabricated by modified injection casting as an alternative method. The distribution, size and composition of the RE inclusions in the metallic fuel slugs were investigated according to the content of the RE inclusions. There were no observed casting defects, such as shrunk pipes, micro-shrinkage or hot tears formed during solidification, in the metallic fuel slugs fabricated by modified injection casting. Scanning electron micrographs and energy-dispersive X-ray spectroscopy (SEM-EDS) showed that the Zr and RE inclusions were uniformly distributed in the matrix and the composition of the RE inclusions was similar to that of a charged RE element. The content and the size of the RE inclusions increased slightly according to the charge content of the RE elements. RE inclusions in U-Zr alloys will have a positive effect on fuel performance due to their micro-size and high degree of distribution.

Energy Performance and Improvement in University Library - Concentrated on 'K'University Library located in Seojong City -

  • Roh, Ji Woong
    • KIEAE Journal
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    • v.14 no.4
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    • pp.47-52
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    • 2014
  • The problem of energy consumption is more serious in university buildings than primary, middle and high school buildings. Because university buildings have generally heating and cooling systems, and various incidental facilities. In university, the library is one of the building that many people use and the most energy is spent. So, investigation on energy saving is very important and urgent. This study aims finally to present the guideline for low-energy design of University library by aiding a designer to select best solution in the side of energy-saving. In this paper, composition of space, utilization schedule and performance of construction materials are grasped, some primary factors that effect to energy saving are analyzed by energy simulation. The result of this study is as follows; First, the subject library has more cooling load than heating load because of cooling load generated during middle season. Second, green roofs is the most effective to heating load saving, but not to cooling energy. Third, outdoor air cooling is the most effective to cooling energy saving among the investigated strategies included in this study.

Comparison of Growth Characteristics and Chemical Composition of Kenaf (Hibiscus cannabinus L.) Varieties as a Potential Forage Crop (케나프 신육성 및 수집 품종의 생육과 사료적 특성 조사)

  • Lee, Ji-Yeon;Velusamy, Vijayanand;Koo, Ja-Yong;Ha, Bo-Keun;Kim, Dong-Sub;Kim, Jin-Baek;Kim, Sang-Hoon;Kang, Si-Yong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.57 no.2
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    • pp.132-136
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    • 2012
  • Kenaf (Hibiscus cannabinus) is an annual herbaceous plant of the family Malvacease that has been planted in tropical Africa and Asia region for more than 4000 years and use as source of fiber, energy and feed stock. In this study, the physiological characters and chemical compositions of kenaf mutant variety "Jangdae" developed using gamma irradiation at the Korea Atomic Energy Research Institute (KAERI) were compared with three genetic resources (Auxu, C12, and C14-DRS). Jangdae showed the highest productivity growth rates in fresh yield, dry weight (DW) yield (leaf and stem), node number, and stem thickness. Especially, leaf DW yield of Jangdae was 1.6-3.1 times higher than that of three genetic resources. Also, stem DW yield of Jangdae was 1.6-2.1 times higher than that of three genetic resources. In the analysis of chemical composition, Jangdae showed 16.9% of crude protein content that was 0.86-0.94 times lower than three cultivars. However, Jangdae showed the highest neutral detergent fiber (NDF) contents in leaf (32.5%) and stem (75.2%). Also, acid detergent fiber (ADF) contents of stem and leaf in Jangdae were 64.4% and 33.9%, respectively. Total polyphenol and total flavonoid contents were 22.1 mg/g and 7.4 mg/g in Jangdae. Based on these results, Jangdae would have the potential to become a successful forage crop.

Bone Mineral Density of Korean Mother-daughter Pairs : Relations to Anthropometric Measurement, Body Composition, Bone Markers, Nutrient Intakes and Energy Expenditure (모녀간의 골밀도 : 신체 측정치 및 체조성, 골지표, 영양소 섭취량 및 에너지 소비량과의 관계)

  • 이희자
    • Journal of Nutrition and Health
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    • v.29 no.9
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    • pp.991-1002
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    • 1996
  • The objectives of this study were to obtain normative data for 45 mother-daughter pairs on spine, femur(neck, ward's triangle, trochanter) and total body BMD (bone mineral density) measured by dual energy X-ray absorptiometry, anthropometric measurement, body composition, biochemical markers, nutrient intakes and energy expenditure, to determin the interrelations of these factors within each group, to measure familial resemblance for each variable. We observed significantly positive correlations between height, weight, head, hip and calf circumferences, tricep, femur and calf skinfold thickness, total lean body mass(=weight-total fat body mass-bone mineral content), protein and fat intakes, Ca index, serum total protein and albumin of monter-daughter pairs(p<.05-p<.001). Among mothers, age, osteocalcin, higher, weight, Ca and energy intakes were predictors of BMDs. Among daughters, weight and energy intake were predictors of BMDs. The BMD in lumbar spine(r=.48, p<.01), femoral neck(r=.38, p<.05), ward's triangle(r=.36, p<.05) of the mothers were significantly correlated with those of the daughters, after adjustment for mother's age, hight, weight, osteocalcin, Ca and energy intakes and daughter's weight, energy intake. In regression analyses, mother's BMD also were positively associated with daughter's BMD in lumbar spine, femoral neck, ward's triangle. Our findings support that mothers with low BMD tended to have daughters with low BMD. In the age groups studied, as well genetic factors as environmental factors may have an important role in determining BMD. This study suggests that women may successfully enhance their genetically determined BMD through adequate nutrient intakes and weight bearing exercise.

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Assessment of Body Condition in Amphibians Using Radiography: Relationship between Bone Mineral Density and Food Resource Availability (방사선 촬영 기법을 이용한 양서류 신체상태 평가: 골밀도와 먹이 자원 가용성 간의 상관 관계)

  • Park, Jun Kyu;Do, Yuno
    • Korean Journal of Ecology and Environment
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    • v.52 no.4
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    • pp.358-365
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    • 2019
  • We measured the body composition, including bone mineral density (BMD) and food resource availability using dual energy X-ray absorptiometry and the carbon and nitrogen stable isotope ratios of body condition of 4 anuran species(Hyla japonica, Glandirana rugosa, Pelophylax nigromaculatus, Lithobates catesbeianus) in South Korea. Additionally, the carbon and nitrogen stable isotope ratios were employed to determine the food resource availability of anurans. We figured out the relationship between the body composition, including BMDs and food resource availability. The body composition and BMDs did not differ between male and female while there was difference among the species. Food resource availability and BMDs were the highest in L. catesbeianus, the lowest in H. japonica. BMDs tended to increase with higher food resource availability. Body composition and BMDs, which represent the body condition of an individual, can be used as an ecological indicator to assess the stability of the habitat of anurans.

Concentration of Polybrominated Diphenyl Ethers and Their Composition in Octopus minor Collected from Seosan Intertidal Zone (낙지(Octopus minor)에서의 브롬계화합물(Polybrominated diphenyl ethers, PBDEs)의 잔류농도와 조성특성)

  • Lee, Hyo-Jin;Kim, Gi-Beum;Stapleton, Heather
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.13 no.1
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    • pp.68-74
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    • 2010
  • Octopus(Octopus minor), benthic cephalopod, were collected from intertidal zone in Seosan, Choongnam and analyzed for polybrominted diphenyl ethers(PBDEs). PBDEs concentrations ranged from 29 to 109 ng/g lipid wt(mean; 54 ng/g) in mantle and from 12 to 89 ng/g lipid wt(mean; 48 ng/g) in internal organ. PBDEs concentrations in octopus internal organ were lower about two times than that in common squid collected in Yellow Sea, indicating Seosan is relatively less contaminated with PBDEs. Major congener was BDE 206, occupying 72% and 49% of total PBDE concentration in mantle and in internal organ, respectively, which is very different from PBDE composition in common squid with major congeners of BDE 47 and 99. From PBDE composition, octopus seemed to concentrate higher brominated BDE rather than lower brominated BDE. This PBDE composition in octopus may be affected by sediment with extremely high contribution of deca-BDE to total PBDE concentration.

Experimental Investigation of the Effect of Composition on the Performance and Characteristics of PEM Fuel Cell Catalyst Layers

  • Baik, Jung-Shik;Seong, Dong-Mug;Kim, Tae-Min
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.06a
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    • pp.157-160
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    • 2007
  • The catalyst layer of a proton exchange membrane (PEM) fuel cell is a mixture of polymer, carbon, and platinum. The characteristics of the catalyst layer play critical role in determining the performance of the PEM fuel cell. This research investigates the role of catalyst layer composition using a Central Composite Design (CCD) experiment with two factors which are Nafion content and carbon loading while the platinum catalyst surface area is held constant. For each catalyst layer composition, polarization curves are measured to evaluate cell performance at common operating conditions, Electrochemical Impedance Spectroscopy (EIS), and Cyclic Voltammetry (CV) are then applied to investigate the cause of the observed variations in performance. The results show that both Nafion and carbon content significantly affect MEA performance. The ohmic resistance and active catalyst area of the cell do not correlate with catalyst layer composition, and observed variations in the cell resistance and active catalyst area produced changes in performance that were not significant relative to compositions of catalyst layers.

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Study on the check list composition at Sustainable building strategies and Design methods of Long-life housing (장수명 공동주택의 친환경 요소기술 및 계획기법 체크리스트 구성에 관한 연구)

  • Han, Nam-Soo;Lee, Young
    • Journal of the Korean housing association
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    • v.21 no.1
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    • pp.103-112
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    • 2010
  • This Study is about the check-List composition for 'Low carbon green growth' of Long-life housing. That utilization for required the check-list composition at Sustainable building strategies and Design methods. That for long life housing, sustainable building strategies part of building construction and interior, the proper foundation for legislative system, maintenance methods with in building life cycle, sustainable and green architecture capability realization prepare for connection plan with 'Low carbon-green growth'. Extracting from elements of Architectural planing answer to basic concept of Low carbon-green growth and aimed at Low carbon scheme for energy saving, green growth scheme for environmental conservation as to each application purpose reconstitute by classify Check-list category about elements of Architectural planing. Through this architectural research deduce elements of architectural planing that can be research utilization with in Check-list composition.