• Title/Summary/Keyword: Total potential energy

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Importance Analysis of Radiological Exposure by Ground Deposition in Potential Accident Consequences for the Licensing Approval of a Nuclear Power Plant (원전 인허가승인을 위한 사고결말평가에서 지표침적에 의한 피폭의 민감도 분석)

  • Hwang, Won Tae;Jeong, Hae Sun;Jeong, Hyo Joon;Kim, Eun Han;Han, Moon Hee
    • Journal of Radiation Protection and Research
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    • v.39 no.2
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    • pp.89-95
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    • 2014
  • In potential accident consequence assessments for the licensing approval of LWRs, the ground deposition of radionuclides released into the environment is not allowed into the models, as recommended in the U. S. Nuclear Regulatory Commission's regulatory guide. Meanwhile, it is allowed into the assessment models for the licensing approval of PHWRs with consideration of more detailed physical processes of radionuclides in the atmosphere. Under these backgrounds, importance of exposure dose by ground deposition was quantitatively evaluated and comprehensively discussed. For potential accidental releases of $^{137}Cs$ and $^{131}I$, total exposure doses were more conservative in case of without consideration of ground deposition than in case of with its consideration. It was because of that the depletion of air concentration resulting from ground deposition is more influential in the contribution to total exposure doses than additional doses from contaminated ground. The exposure doses by the inhalation of contaminated air showed the contribution of more than 90% in total exposure doses, depending on atmospheric stability, release period of radionuclides and distance from a release point. The exposure doses from contaminated ground showed less than 10% at most in contribution of total exposure doses. The ratios of total exposure doses in case of with consideration of deposition to without its consideration for $^{131}I$ were distinct than those for $^{137}Cs$. As the atmosphere is more stable, release duration of radionuclides is longer, distance from a release point is longer, it was more distinct.

Studying the nonlinear behavior of the functionally graded annular plates with piezoelectric layers as a sensor and actuator under normal pressure

  • Arefi, M.;Rahimi, G.H.
    • Smart Structures and Systems
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    • v.9 no.2
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    • pp.127-143
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    • 2012
  • The present paper deals with the nonlinear analysis of the functionally graded piezoelectric (FGP) annular plate with two smart layers as sensor and actuator. The normal pressure is applied on the plate. The geometric nonlinearity is considered in the strain-displacement equations based on Von-Karman assumption. The problem is symmetric due to symmetric loading, boundary conditions and material properties. The radial and transverse displacements are supposed as two dominant components of displacement. The constitutive equations are derived for two sections of the plate, individually. Total energy of the system is evaluated for elastic solid and piezoelectric sections in terms of two components of displacement and electric potential. The response of the system can be obtained using minimization of the energy of system with respect to amplitude of displacements and electric potential. The distribution of all material properties is considered as power function along the thickness direction. Displacement-load and electric potential-load curves verify the nonlinearity nature of the problem. The response of the linear analysis is investigated and compared with those results obtained using the nonlinear analysis. This comparison justifies the necessity of a nonlinear analysis. The distribution of the displacements and electric potential in terms of non homogenous index indicates that these curves converge for small value of piezoelectric thickness with respect to elastic solid thickness.

Dietary Intakes and Status of Folate in Koean Women of Child-bearing Potential (가임기 여성의 엽산 섭취량 및 엽산영양상태)

  • 임현숙
    • Journal of Nutrition and Health
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    • v.33 no.3
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    • pp.296-303
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    • 2000
  • We examined the folate intakes and assessed folate nutritional status of Korean women with childbearing potential. A total of 91 healthy women aged between 15 and 49 participated. They were divided into three groups by their age : A(15-24 yrs), B(25-34 yrs) and C(35-49 yrs). Folate intakes were determined by direct analysis. The foods consumed for 24 hours were collected proportionally and assessed folate. Their blood drawn in fasting state were analyzed folate levels. Folate contents of food homogenate, plasma and erythrocyte were determined a microbiological method using Lactobacillus. casei (ATCC 7469). Prior to the micro-assay, the food homogenate were treated with alpha-amylase, protease and folate conjugase. Mean daily folate intake of the total subjects was 145.8$\mu\textrm{g}$/d and in each group of A, B, and C was 114.0$\mu\textrm{g}$/d, 141.6$\mu\textrm{g}$/d, and 164.6$\mu\textrm{g}$/d, respectively. That of group C was significantly higher than that of group A(p<0.05). However, those of all the groups were lower than compared to the Korean Recommened Dietary Allowances(RDA) for folate. Especially the subjects in the group A consumed folate least that was below the half of the Korean RDA. The mean energy intake of all subjects was 1638㎉/d and those in each group of A, B, and C did not meet the Korean RDA for energy. The energy intake were significantly correlated with folate intakes(r=0.5050, p<0.001). Mean plasma and erythrocyte folate concentrations of total subjects were 6.9ng/mL and 266.3ng/mL, respectively. None were found to be deficient both in plasma(<3ng/mL)and erythrocyte (<140ng/mL) folate levels. There was only one subject who had red blood cell folate level below 157ng/mL concentration. These results show that folate status of the Korean women of reproductive age is not much bad. But it should be better that letting them improve their folate status by increasing energy intake, choosing high folate foods.

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The Effect of Urban Trees on Residential Solar Energy Potential (도심 수목이 분산형 주거 태양광에너지 잠재량에 미치는 영향)

  • Ko, Yekang
    • Journal of the Korean Institute of Landscape Architecture
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    • v.42 no.1
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    • pp.41-49
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    • 2014
  • This study spatially assesses the impact of trees on residential rooftop solar energy potential using urban three-dimensional models derived from Light Detection and Ranging(LiDAR) data in San Francisco, California. In recent years on-site solar energy generation in cities has become an essential agenda in municipal climate action plans. However, it can be limited by neighboring environments such as shade from topography, buildings and trees. Of all these effects, the impact of trees on rooftop photovoltaics(PVs) requires careful attention because improper situation of solar panels without considering trees can result in inefficient solar energy generation, tree removal, and/or increasing building energy demand and urban heat island effect. Using ArcMap 9.3.1, we calculated the incoming annual solar radiation on individual rooftops in San Francisco and the reduced insolation affected by trees. Furthermore, we performed a multiple regression analysis to see what attributes of trees in a neighborhood(tree density, tree heights, and the variance of tree heights) affect rooftop insolation. The result shows that annual total residential rooftops insolation in San Francisco is 18,326,671 MWh and annual total light-loss reduction caused by trees is 326,406 MWh, which is about 1.78%. The annual insolation shows a wide range of values from $34.4kWh/m^2/year$ to $1,348.4kWh/m^2/year$. The result spatially maps the locations that show the various levels of impact from trees. The result from multiple regression shows that tree density, average tree heights and the variation of tree heights in a neighborhood have statistically significant effects on the rooftop solar potential. The results can be linked to municipal energy planning in order to manage potential conflicts as cities with low to medium population density begin implementing on-site solar energy generation. Rooftop solar energy generation makes the best contribution towards achieving sustainability when PVs are optimally located while pursuing the preservation of urban trees.

Childbearing women of twenty and under are at greater risk than those of twenty-five and over for compromised folate status

  • Kim, Hee-Ah;Choi, Jeong-Hwa;Lim, Hyeon-Sook
    • Nutrition Research and Practice
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    • v.1 no.4
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    • pp.254-259
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    • 2007
  • This study assessed folate intakes, folate concentrations in plasma and erythrocytes, plasma total homocysteine (tHcy) concentration, and urinary excretion of folate metabolites in Korean women with childbearing potential. A total of 23 women voluntarily participated in this study. Precise dietary intakes for 3 consecutive days were determined by weighing all foods consumed and folate intake was calculated using a computer-aided dietary analysis system. Folate concentration of plasma and erythrocytes was determined by a microbiological method. Plasma tHcy concentration was assayed using an HPLC analysis method. Urine excreted over the same period of time was collected and folate catabolites, para-aminobenzoylglutamate (pABG) and para-acetamidobenzoylglutamate (ApABG), were evaluated using a reverse-phase HPLC method after affinity chromatography. Young women of 20 and under were likely to consume less folate with low energy intake, had lower folate concentration in plasma and erythrocytes, and excreted a lesser amount of ApABG and total folate catabolites than women of 25 years and over. The results of this study confirmed that young Korean women with childbearing potential, especially those under 21 years of age, might be at risk for compromised folate status due to insufficient folate intakes from inadequate energy consumption.

Survey and Economic Analysis of Food Industry Residues for Biomass-to-energy Conversion in Merced and Stanislaus Counties, California, USA (바이오에너지로의 전환을 위한 캘리포니아 식품가공공장 오.폐수 특성 조사 및 경제성 분석)

  • Kim, Dae-Hyun
    • Journal of Biosystems Engineering
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    • v.34 no.4
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    • pp.243-253
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    • 2009
  • This research expands investigations into the biomass resource potential associated with California's food processing industry by surveying industries within a two county region in the San Joaquin Valley, California, USA. A previous survey conducted in 2005 for the Sacramento Municipal Utility District (SMUD) quantified residue and waste generation from food processors and food preparation businesses in the Sacramento region. The present survey investigates residue and waste streams from food processors located in Merced and Stanislaus Counties. Sixty food processors were identified to participate in the survey, of which 49 responded (82%) and data were acquired for 38 (63%) (6 facilities closed or moved, 8 decided not to participate). Within the two counties, total annual waste among survey respondents amounted to 24,044 dry tons of high moisture (${\geq}$60%) food residuals, 5,358 dry tons of low moisture (<60%) food residuals; and 23.7 million $m^3$ of wastewater containing 38,814 tons of biochemical oxygen demand ($BOD_5$). The total potential electric power generation from these food residues was estimated at approximately $7\;MW_e$. Total solid waste resource included in the survey response was estimated at about 10% of statewide residue generation for processors falling within the Standard Industrial Classification (SIC) System Major Group 20 (Food and Kindred Products) categories.

Magnetism and Electronic Structure of Tc Half-monolayer on Pd(oo1) Surface (Pd(001) 위에 올려진 Tc 0.5 웃층의 자성과 전자구조)

  • 김동철;이재일
    • Journal of the Korean Magnetics Society
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    • v.9 no.5
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    • pp.223-226
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    • 1999
  • We have investigated the magnetic properties and the electronic structures of Tc half-monolayer (0.5-ML) on Pd(001) using the full-potential linearized augmented plane wave(FLAPW) energy band method. We calculated the total energies for ferromagnetic and paramagnetic states to determine the stable magnetic state. The calculated results show that the total energy of the ferromagnetic state is lower than that of the paramagnetic one. The overlayer Tc 0.5-ML has considerably large magnetic moment $(2.09\;{\mu}_B)$, while the substrate Pd layers have been negatively polarized. The calculated density of states and total electrons inside the muffin-tin (MT) sphere are presented and discussed in relation with the magnetic properties.

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Spatial Free Vibration and Stability Analysis of Thin-Walled Arches with Variable Curvature (곡률이 변하는 박벽 아치의 3차원 자유진동 및 좌굴해석)

  • 서광진;민병철;김문영
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1999.04a
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    • pp.169-176
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    • 1999
  • An improved formulation for spatial stability md free vibration of thin-walled curved beams with variable curvature and non-symmetric cross sections are presented based on the displacement field considering the second order terms of finite semitangential rotations. By introducing Vlasov's assumptions, the total potential energy is derived from the principle of linearized virtual work for a continuum. In this formulation, all displacement parameters and the warping function are defined at the centroid axis so that the coupled terms of bending and torsion are added to the elastic strain energy. Also, the potential energy due to initial stress resultants is consistently derived corresponding to the semitangential rotation and moment. The cubic Hermitian polynomials are utilized as shape functions for development of the curved thin-walled beam element having eight degrees of freedom. In order to illustrate the accuracy and practical usefulness of this study, . numerical solutions for free vibration of arches are presented and compared with resells of other researchers and solutions analyzed by the ABAQUS's shell element.

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A split kinetic energy solution scheme applied to various delta potentials in quantum mechanical systems

  • Chen, Yu-Hsin;Chao, Sheng D.
    • Coupled systems mechanics
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    • v.6 no.1
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    • pp.17-28
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    • 2017
  • In this work, we extend the previously developed split kinetic energy (dubbed KEP) method by Mineo and Chao (2012) by modifying the mass parameter to include the negative mass. We first show how to separate the total system into the subsystems with 3 attractive delta potentials by using the KEP method. For repulsive delta potentials, we introduce "negative" mass terms. Two cases are demonstrated using the "negative" mass terms for repulsive delta potential problems in quantum mechanics. Our work shows that the KEP solution scheme can be used to obtain not only the exact energies but also the exact wavefunctions very precisely.

No Effect of Energy Intake Overall on Risk of Endometrial Cancers: a Meta-analysis

  • Chu, Ke-Tan;Song, Yang;Zhou, Jian-Hong
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.23
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    • pp.10293-10298
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    • 2015
  • Background: Previous epidemiologic studies on the association between energy intake and endometrial cancer risk have only generated contradictory results. The role of energy intake in endometrial carcinogenesis thus remains unclear. To quantitatively assess the potential association between energy intake and endometrial cancer, a meta-analysis of case-control and cohort studies was here conducted. Materials and Methods: Eligible studies were retrieved via both computerized searches and review of references. Fixed-or random-effect models were used to summarize the estimates of OR with 95%CIs. Stratified analyses on study design, region and macronutrients' calorie were performed. Results: Sixteen studies met the inclusion criteria of the meta-analysis. No association between total energy intake and endometrial cancer was observed in either overall group (OR=1.11, 95%CI 0.92-1.30) or subgroups stratified by study design and region. In the specific macronutrients' calorie analysis, higher fat energy intake was found to be associated with increased endometrial risk (OR=1.72, 95%CI 1.12-2.32) while energy from carbohydrate and protein was not related to endometrial cancer risk. Conclusions: Our analysis did not support that total energy intake is related to endometrial cancer risk, in contrast to fat energy.