• Title/Summary/Keyword: Space Energy

Search Result 3,276, Processing Time 0.13 seconds

Development and Characterization of Multi-Segmented Tissue Equivalent Proportional Counter for Microdosimetry (마이크로 도시메트리용 다분할 조직등가비례계수기의 개발과 특성 평가)

  • Nam, Uk-Won;Park, Won-Kee;Lee, Jaejin;Pyo, Jeonghyun;Moon, Bong-Kon;Moon, Myung Kook;Lim, Chang Hwy;Lee, Suhyun;Kim, Sunghwan
    • Journal of Sensor Science and Technology
    • /
    • v.24 no.2
    • /
    • pp.101-106
    • /
    • 2015
  • We designed, developed and characterized a multi-segmented tissue equivalent proportional (TEPC) counter for microdosimetry. The energy resolution of the multi-segmented TEPC was about 12% for $^{241}Am$ 5.45 MeV alpha particles. The resolution was better than 33% for a single un-segmented TEPC. A compact and low power consumption TEPC could be made by using digital pulse processor (DPP). We also successfully calibrated the TEPC by using $^{252}Cf$ standard neutron source in Korea Research Institute of Standards and Science (KRISS). According to the results, the TEPC is useful for several application of radiation monitoring such as a neutron monitor, air crew monitor and space dosimeter.

Effect of fractional order on energy ratios at the boundary surface of elastic-piezothermoelastic media

  • Kumar, Rajneesh;Sharma, Poonam
    • Coupled systems mechanics
    • /
    • v.6 no.2
    • /
    • pp.157-174
    • /
    • 2017
  • In the present investigation reflection and transmission of plane waves at an elastic half space and piezothermoelastic solid half space with fractional order derivative is discussed. The piezothermoelastic solid half space is assumed to have 6 mm type symmetry and assumed to be loaded with an elastic half space. It is found that the amplitude ratios of various reflected and refracted waves are functions of angle of incidence, frequency of incident wave and are influenced by the piezothermoelastic properties of media. The expressions of amplitude ratios and energy ratios are obtained in closed form. The energy ratios are computed numerically using amplitude ratios for a particular model of graphite and Cadmium Selenide (CdSe). The variations of energy ratios with angle of incidence are shown graphically. The conservation of energy across the interface is verified. Some cases of interest are also deduced from the present investigation.

Case Studies on Space Zoning and Passive Façade Strategies for Green Laboratories

  • Kim, Jinho
    • Architectural research
    • /
    • v.22 no.2
    • /
    • pp.41-52
    • /
    • 2020
  • Laboratory buildings with specialized equipment and ventilation systems pose challenges in terms of efficient energy use and initial construction costs. Additionally, lab spaces should have flexible and efficient layouts and provide a comfortable indoor research environment. Therefore, this study aims to identify the correlation between the facade of a building and its interior layout from case studies of energy-efficient research labs and to propose passive energy design strategies for the establishment of an optimal research environment. The case studies in this paper were selected from the American Institute of Architects Committee on the Environment Top Ten Projects and Leadership in Energy and Environmental Design (LEED) certified research lab projects. In this paper, the passive design strategies of space zoning, façade design devices to control heating and cooling loads were analyzed. Additionally, the relationships between these strategies and the interior lab layouts, lab support spaces, offices, and circulation areas were examined. The following four conclusions were drawn from the analysis of various cases: 1) space zoning for grouping areas with similar energy requirements is performed to concentrate similar heating and cooling demands to simplify the HVAC loads. 2) Public areas such as corridor, atrium, or courtyard can serve as buffer zones that employ passive solar design to minimize the mechanical energy load. 3) A balanced window-to-wall ratio (WWR), exterior shading devices, and natural ventilation systems are applied according to the space programming energy requirements to minimize the dependence on mechanical service. 4) Lastly, typical laboratory space zoning categories can be revised, reversed, and even reconfigured to minimize the energy load and adjust to the site context. This study can provide deep insights into various design strategies employed for construction of green laboratories along with intuitive arrangement of various building components such as laboratory spaces, lab support spaces, office spaces, and common public areas. The key findings of this study can contribute towards creating improved designs of laboratory facilities with reduced carbon footprint and greenhouse emissions.

Analysis of Biomass Energy Potential around Major Cities in South Korea (국내 주요도시 주변의 바이오매스 에너지 잠재량 분석)

  • Kook, Jin Woo;Lee, See Hoon
    • Applied Chemistry for Engineering
    • /
    • v.26 no.2
    • /
    • pp.178-183
    • /
    • 2015
  • Biomass is recognized as one of important renewable energy sources because it can be converted and used as solid, gaseous and liquid forms. Also, biomass is one of promising ways to solve the depletion of fossil fuels and global warming problems. The information about local biomass energy potentials and space energy densities can be powerfully utilized to determine the scale of biomass energy conversion plant and to analyze economic effects. The latest data on domestic biomass resources, such as agricultural, forestry, livestock and urban wastes, were collected from various government organizations and institutes and were analyzed to calculate biomass energy potential and space energy density. As local areas in South Korea to collect biomass resources increased, energy potentials increased, but space energy densities of total biomass decreased.

A Study to Derive Energetics of Coronal Magnetic Structures

  • Kang, Jihye;Magara, Tetsuya;Inoue, Satoshi;Lee, Hwanhee;An, Jun-Mo
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.37 no.2
    • /
    • pp.127.2-127.2
    • /
    • 2012
  • Space weather prediction related to flares and CMEs is an important issue these days. It is, however, hard to estimate magnetic energy of invisible coronal magnetic structure. The virial theorem is one of the ways to determine the magnetic energy. In this study, we performed a series of MHD simulation of an emerging flux tube and apply the virial theorem to the simulation results and derive energetics of coronal structures. We then analyze real observational data on NOAA 11302 to derive the distributions of physical quantities, such as density, temperature, velocity and magnetic field. We also use knowledge form simulation analysis to estimate the magnetic energy of NOAA 11302.

  • PDF

Electromagnetic Field and the Poetry of Ezra Pound

  • Ryoo, Gi Taek
    • Journal of English Language & Literature
    • /
    • v.57 no.6
    • /
    • pp.939-958
    • /
    • 2011
  • Ezra Pound has an idea of poetry as a field of energy in which words interact with each other with kinetic energy. The energy field which Pound creates in his poem is analogous to the theory of electromagnetism developed by Michael Faraday and James Maxwell, who look upon the space around magnets, electric charges and currents not as empty but as filled with energy and activity. Pound argues that "words are charged with force like electricity," demonstrating that words charged with their own images or energies of positive or negative valence interact one another. This idea is similar to Faraday's concept of "line of force" which he used to represent the disposition of electric and magnetic forces in space. Pound's concept of "image" as an "intellectual and emotional complex in an instant" is remarkably consonant with the confluence of electric and magnetic fields that are coupled to each other as they travel through space in the form of electromagnetic waves. The instant profusion of conception and perception, much like that of electric and magnetic fields, enables Pound to move beyond the sequential and linear hierarchy in time and space. Particularly, Maxwell's stunning discovery that the electromagnetic waves propagate in space at 'the speed of light' has allowed Pound a relativistic sense of escape from the limitations of Newtonian absolute time and space. Pound's poetry transcends any geographical space and sequential time by rendering and juxtaposing images simultaneously. Pound was fully aware of light and electricity fundamental to what he called his world "the electric world." Pound's experiments in Imagism and Vorticism can be considered an attempt to rediscover a place for poetry in the modern world of science and technology. Almost all the appliances that we think of today as modern were laid down in the closing decades of the 19th century and the first decades of the 20th century, in response to the availability of electromagnetic energy. This paper explores how Pound responded to the age of modern technology and science, examining his conception of "image" through his many analogies and similes drawn from electromagnetism. Pound's imagist poetics and poetry come to embody, not only the characteristics of the electric age in the early twentieth century, but the principles of electromagnetism the electric age is based upon.

DEVELOPMENT OF A WALL-TO-FLUID HEAT TRANSFER PACKAGE FOR THE SPACE CODE

  • Choi, Ki-Yong;Yun, Byong-Jo;Park, Hyun-Sik;Kim, Hee-Dong;Kim, Yeon-Sik;Lee, Kwon-Yeong;Kim, Kyung-Doo
    • Nuclear Engineering and Technology
    • /
    • v.41 no.9
    • /
    • pp.1143-1156
    • /
    • 2009
  • The SPACE code that is based on a multi-dimensional two-fluid, three-field model is under development for licensing purposes of pressurized water reactors in Korea. Among the participating research and industrial organizations, KAERI is in charge of developing the physical models and correlation packages for the constitutive equations. This paper introduces a developed wall-to-fluid heat transfer package for the SPACE code. The wall-to-fluid heat transfer package consists of twelve heat transfer subregions. For each sub-region, the models in the existing safety analysis codes and the leading models in literature have been peer reviewed in order to determine the best models which can easily be applicable to the SPACE code. Hence a wall-to-fluid heat transfer region selection map has been developed according to the non-condensable gas quality, void fraction, degree of subcooling, and wall temperature. Furthermore, a partitioning methodology which can take into account the split heat flux to the continuous liquid, entrained droplet, and vapor fields is proposed to comply fully with the three-field formulation of the SPACE code. The developed wall-to-fluid heat transfer package has been pre-tested by varying the independent parameters within the application range of the selected correlations. The smoothness between two adjacent heat transfer regimes has also been investigated. More detailed verification work on the developed wall-to-fluid heat transfer package will be carried out when the coupling of a hydraulic solver with the constitutive equations is brought to completion.

Energy Efficiency Evaluation of Heating and Cooling Systems as Space Program in Renovated Library (도서관의 공간사용 특성에 따른 냉난방설비 리모델링의 경제성 평가)

  • Park, Kang-Hyun;Cha, Jung-Hoon;Kim, Su-Min;Park, Kyung-Won
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.24 no.3
    • /
    • pp.205-211
    • /
    • 2012
  • Unlike the previous approaches, we analyzed for economic efficiency of renewed heating and cooling systems as the characteristics of space. The purpose of this study is to analysis the energy consumption and economical efficiency of absorption chillers and EHP systems in renovated library. It is important that equipment selection should be considering energy cost as well as space program. In recently, many EHP systems were installed in the building for reducing the energy cost and for seeking the convenience of individual control. In contrast, though absorption chillers have the disadvantage of a central control, absorption chillers are appropriate for the conditions of the library that needs simultaneous operation. The results by payback period method, show that selection of heating and cooling systems should be consider for space program and the characteristics of space.

A Statistical Test of the Relationship Between Chorus Wave Activation and Anisotropy of Electron Phase Space Density

  • Lee, Dong-Hee;Lee, Dae-Young;Shin, Dae-Kyu;Kim, Jin-Hee;Cho, Jung-Hee
    • Journal of Astronomy and Space Sciences
    • /
    • v.31 no.4
    • /
    • pp.295-301
    • /
    • 2014
  • Whistler mode chorus wave is considered to play a critical role in accelerating and precipitating the electrons in the outer radiation belt. In this paper we test a conventional scenario of triggering chorus using THEMIS satellite observations of waves and particles. Specifically, we test if the chorus onset is consistent with development of anisotropy in the electron phase space density (PSD). After analyzing electron PSD for 73 chorus events, we find that, for ~80 % of them, their onsets are indeed associated with development of the positive anisotropy in PSD where the pitch angle distribution of electron velocity peaks at 90 degrees. This PSD anisotropy is prominent mainly at the electron energy range of ${\leq}$ ~20 keV. Interestingly, we further find that there is sometimes a time delay among energies in the increases of the anisotropy: A development of the positive anisotropy occurs earlier by several minutes for lower energy than for an adjacent higher energy.

Space Weather and Relativistic Electron Enhancement

  • Lee, J.J.;Parks, G.K.;McCarthy, M.P.;Min, K.W.;Lee, E.S.;Kim, H.J.;Park, J.H.;Hwang, J.A.
    • Bulletin of the Korean Space Science Society
    • /
    • 2006.10a
    • /
    • pp.52-52
    • /
    • 2006
  • Many spacecraft failures and anomalies have been attributed to energetic electrons in the Earth's magnetosphere. While the dynamics of these electrons have been studied extensively for several decades, the fundamental question of how they are accelerated is not fully resolved. Proposed theories have not been successful in explaining fast high energy increase such as REE (Relativistic electron enhancement). In this presentation, we show observations of energetic electron precipitation measured by the Korean satellite, STSAT-1 which simultaneously detect (100ev - 20 keV) and (170 - 360 keV) energy electrons at the 680 km orbit, when the RES event observed at the geosynchronous orbit on October 13, 2004. STSAT-1 observed intense electron precipitation in both energy ranges occurred in the midnight sector clearly demonstrating that electrons having wide energy band are injected from the plasma sheet. To make the balance between loss and injection, the injected electron flux should be also large. In this situation, the injected electrons can be trapped into the magnetosphere and produce REE, though they have low e-folding energies. We propose this plasma sheet injection might be the primary source of relativistic electron (1 MeV) flux increases.

  • PDF