• Title/Summary/Keyword: Lead Space

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Advanced Silicon Solar Cell Structures for Space Applications

  • Lee, S.H.;Kim, D.S.
    • Solar Energy
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    • v.17 no.2
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    • pp.23-33
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    • 1997
  • This paper reviews the advanced solar cell structures used in space. These are the structures which incorporate the back surface field and reflectors with very shallow and lightly doped emitters. Their use in space has shown that the thinner cells are more resistive to radiation damage than the thicker ones. It has been found that the charged particles affect both the surface and bulk of the cells used in space. This causes degradation in the output power, which in effect, can be explained by the degrading diffusion length of the cells. The PERL cells showed higher BOL(beginning of life) efficiency and almost the same EOL(end of life) efficiency as structures with wrap-around contact configuration fabricated on 10 ${\Omega}cm$ resistivity substrates. This observation lead to a conclusion that, the space cells do not necessarily need to have very high BOL efficiency except in specific missions which require such.

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A Study on Design of the Exhibition Space in the Railroad Car (철도차량내의 전시공간 디자인에 관한 연구)

  • Choi, Chul-Joo;Hong, Suk-Ki;Kwon, Tae-Soo
    • Proceedings of the KSR Conference
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    • 2003.10b
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    • pp.197-202
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    • 2003
  • A Railroad Cars playa prominent role in a matter of transportation yet it cannot be discussed here for cultural space. On the other hand, considering railroad customers' increaced desire(craving) for cultural space, we design it in the train so that we provide customers not only transportation but also fullfil them desire for culture. In the competitive cultural era. The aim of the new strategy for railroad bussiness is both inspiving art and operating exhibition facilities in the train(railroad). Through analysis of exhibition space and environment, we design exhibition space to equip cultural facilities in the train then lead to make railroad business' new social education role by the inside and outside of the country.

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An approach to the coupled dynamics of small lead cooled fast reactors

  • Zarei, M.
    • Nuclear Engineering and Technology
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    • v.51 no.5
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    • pp.1272-1278
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    • 2019
  • A lumped kinetic modeling platform is developed to investigate the coupled nuclear/thermo-fluid features of the closed natural circulation loop in a low power lead cooled fast reactor. This coolant material serves a reliable choice with noticeable thermo-physical safety characteristics in terms of natural convection. Boussienesq approximation is resorted to appropriately reduce the governing partial differential equations (PDEs) for the fluid flow into a set of ordinary differential equations (ODEs). As a main contributing step, the coolant circulation speed is accordingly correlated to the loop operational power and temperature levels. Further temporal analysis and control synthesis activities may thus be carried out within a more consistent state space framework. Nyquist stability criterion is thereafter employed to carry out a sensitivity analysis for the system stability at various power and heat sink temperature levels and results confirm a widely stable natural circulation loop.

A Study on the Stability of Underground Structure considering the Orientation and the Stiffness of Discontinuity (불연속면의 경사와 강성을 고려한 지하구조물 안정성에 관한 연구)

  • Lee, Seung-Ho
    • Tunnel and Underground Space
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    • v.7 no.1
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    • pp.65-74
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    • 1997
  • Underground structures show different behaviors depending upon the space and the mechanical characteristics of discontinuities, such as joints, beddings, faults and shear zone. Desingning the rock structeres without considering the significance of these discontinuities can lead to false conclusions. This paper includes study on the following topics; the numerical analysis of continuous rock and discontinuous rock around a tunnel, the influences on shotcrete moment and rock-bolt axial force of tunnel due to different joint orientation and stiffness.

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Influence of Endurance tests on Space Charge Distribution of 160kV HVDC XLPE Cable

  • Liu, Yun-Peng;Liu, He-Chen
    • Journal of Electrical Engineering and Technology
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    • v.12 no.1
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    • pp.302-309
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    • 2017
  • The ageing of XLPE cable insulation will lead to the accelerating accumulation of space charge, which will greatly affect the safe operation of the HVDC cable. In order to investigate the influence of different ageing modes on the space charge distribution of the HVDC cable, thermal stressed, electrical stressed and electro-thermal stressed endurance tests were carried out on the XLPE peelings. The tested XLPE peelings were obtained from 160kV HVDC cable insulation. The endurance tests were carried at thermal stress of 363K, electrical stress of 20kV/mm DC and a combination of both. The Pulsed Electro-Acoustic (PEA) method was used to measure the space charge distribution of the samples. The influences of ageing on the trap energy distribution were analyzed based on the isothermal relaxation theory and the decay characteristics of the space charge. The results showed that thermal ageing would help to improve the crystalline morphologies of the XLPE at the early stage. The total amount of space charge decreased compared to the ones before thermal ageing. The long term of electrical stress would result in the cleavage of polymer molecule chains which would intensify the accumulation of space charge and increase the density and depth of electron traps. With a combination of electrical and thermal stress, the injection and migration of space charge were more significant. Besides, the depth and density of electron traps increased rapidly with the increase of endurance time.

Remedial Measures of Ordinances and Regulations on landscaping at Site Level -The Case of Local Governments in Chollabuk-Do- (대지내의 조경관련 조례와 규제제도의 개선방안 -전라북도의 기초지방자치단체를 중심으로-)

  • 김남희;이명우
    • Journal of the Korean Institute of Landscape Architecture
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    • v.28 no.1
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    • pp.37-47
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    • 2000
  • This research focused on the improved alternatives of the ordinance which practically control the open space in-situ, public open space and landscape construction related to city landscape for the healthy physical and mental life of the city dwellers. The contents of the study are as follows: 1. The special law of Landscape Architecture should be legislated. 2. The portion of landscaping should be changed by up-grading in the Ordinance of Landscape area and planting and the terms of landscape Facilities should include the ecological aspects in it's contents in the law. 3. The administration of local governments should actively lead and support the dwellers to make the roof gardens and the window gardens in the building area of cities or commercial districts which have relatively low rate of green space. 4. Any new construction and restoration of the buildings with preservation of the natural environment and creation of public open space should be given incentive and Set-back space in aesthetic area should have appropriate planting area and facilities in it. 5. Organizing professional landscape evaluation committee and composing evaluation standards are very important because of the contemporary proposition of the establishment of the establishment of ecological space and conservation of urban natural space. Because of the characteristics of Landscape Architecture, the Provisions of landscape Architecture Design and landscape architecture supervision of the specialist should be legislated and the Landscape Architectural Organization should be established within the Government.

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A Study on analyzing the space of Villa VPRO used datascape design strategy (데이터스케이프 설계방법을 적용한 Villa VPRO 공간분석 연구)

  • 박영경
    • Korean Institute of Interior Design Journal
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    • v.13 no.3
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    • pp.145-152
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    • 2004
  • The European architects including MVRDV, Rem Koolhaas, Van Berkel, and Zaha Hadid tend to use the their own design strategy based on the objective data. This Architectural design method leads to make new paradigm of contemporary architecture. For the purpose of the understanding a part of new architecture paradigm I will analyze the case of Villa VPRO designed by MVRDV. At the result, I can draw the following conclusions. First, through collecting and analyzing data, drawing design concept and planning the space program, they decided on the design strategies of Villa VPRO. They designed the space volume having 42.4m$\times$42.4m floors and infiltrated environmental elements to solve the problems about deep space. Second, Villa VPRO was constructed by 'creative space-making system: a series of floors much like a geological formation, the continuous floors interconnected by spatial means, the precision bombardments of snake-like holes, open elevations, the stacking spaces. Third, Villa VPRO produced the spectacle space effect the various formation of continuous floors make a lot of difference space types in this building. Also they lead to move naturally and give event space. A numbers of holes and openness make it possible to provide friendly environment with combining light and air with views of the surrounding and transparency. And using the method of stacking many types of space make the differences in height.

A Study on the Characteristics of Space Design in Isamu Noguchi's Works - Focused on Stage Sets and Environmental Design Works (이사무 노구치 작품에 나타난 공간디자인 특성연구 -무대디자인 및 환경디자인 작품을 중심으로 -)

  • 한민정;손광호
    • Korean Institute of Interior Design Journal
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    • no.27
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    • pp.120-127
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    • 2001
  • The purpose of this study is to examine the characteristics of space design of Isamu Noguchi's works barred on the stage sets and environmental designs. From the end of 19th century, space which was begun to be studied about in architects has continued to be researched by not only scientists but artists. Recently, space Is expressed in free and new forms due to diversity of societies and advancement of technology, As a result, space has become an essential part in art and is used in the titles of many art exhibitions. This study scrutinizes space in Isamu Noguchi's works. No other 20th century artist has as clear and progressive space conception as Noguchi's. His notion of modern art was modified through space in the tradition of cubism and Russian Constructivism and Bauhaus. Combined with his experience in the traditional Japanese houses and gardens, these influences led toward a broadened conception of sculpture as the creation of living space. These modernist's characteristics are found in his early expression of stage sets for choreographer Martha Graham, and they would lead to a wide range of design activities, from gardens and interiors to fountains and furniture. Isamu Noguchi had created a body of work that crossed the boundary between fine and applied art as a sculptor, and as an environmental designer.

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Exploration of Isovist Fields to Model 3D Visibility With Building Facade

  • Chang, Dong-Kuk;Park, Joo-Hee
    • Architectural research
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    • v.13 no.3
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    • pp.19-29
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    • 2011
  • Visibility of a space have been defined in several different ways: such as the axial line covering a convex space, a convex space defining the fattest shape in a space and an Isovist field formed by a field of vision at a given vantage point. Isovist fields are referred to as a descriptive medium to describe a movement by reviewing and analyzing geometric properties in them. Many descriptive methods for analysis of three-dimensional isovist are applied to analyzing the morphological properties in a 3D space more realistically. Although these models are regarded as a more advanced method for describing spatial properties, they have pros and cons such as complex mathematical calculations and somewhat arbitrary calibration in addition to huge consumption of memory space. These difficulties lead to the development of a three-dimensional visual accessibility model that explores the implication of building shape on the calculation of isovist fields drawn on a 2D plane. We propose a conceptual framework of how to measure the isovist field not as a 3D volume but as a combination of 2D plane on the ground with the 3D building shape of it's facade.

Direct Measurement of Blast Pressure in Near Field with Lead Plate Blast Pressure Meter (Lead Plate Blast Pressure Meter를 이용한 근거리 기폭의 발파압 계측)

  • Ko, Young-Hun;Jang, Hyong-Doo;Yang, Hyung-Sik
    • Tunnel and Underground Space
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    • v.22 no.1
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    • pp.54-59
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    • 2012
  • Deformation of Lead plate blast pressure meter were measured after they were exposed to surface blasting. Blasting pressure was determined by comparing the data with calibration graph which was drawn from the laboratory experiments with gas gun of Hopkinson bar tester. The results were compared with calculated values from the equations of CONWEP (Conventional Weapons Effects Program) and DDESB (Department of Defence Explosives Safety Board). Measured values were lower than calculated values in near field. Gradual decaying tendency of the pressure was observed. It means that estimated blasting pressure of very near field with theoretical equations can be uncertain.