• Title/Summary/Keyword: James

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Vulnerability of roofing components to wind loads

  • Jayasinghe, N.C.;Ginger, J.D.
    • Wind and Structures
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    • v.14 no.4
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    • pp.321-335
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    • 2011
  • The vulnerability of roofing components of contemporary houses built in cyclonic regions of Australia is assessed for increasing wind speeds. The wind loads and the component strengths are treated as random variables with their probability distributions derived from available data, testing, structural analysis and experience. Design details including types of structural components of houses are obtained from surveying houses and analyzing engineering drawings. Wind load statistics on different areas of the roof are obtained by wind tunnel model studies and compared with Australian/New Zealand Standard, AS/NZS 1170.2. Reliability methods are used for calculating the vulnerability of roofing components independently over the roof. Cladding and batten fixings near the windward gable edge are found to experience larger negative pressures than prescribed in AS/NZS 1170.2, and are most vulnerable to failure.

BASELINE MEASUREMENTS ON THE PERFORMANCE OF FOUR CONSTRUCTED WETLANDS IN TROPICAL AUSTRALIA

  • Fell, A.;Jegatheesan, V.;Sadler, A.;Lee, S.H.
    • Environmental Engineering Research
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    • v.10 no.6
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    • pp.316-327
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    • 2005
  • Constructed wetlands provide several benefits that are not solely limited to storm water management and are becoming common in storm water management. In this research, four recently constructed wetlands underwent in situ and laboratory water sampling to determine their efficiency in removing storm water pollutants over a 5-month period. From the sampling results, it was determined that each of the wetlands was able to reduce the concentration of pollutants in the stormwater. To aid in the assessment of the wetlands against each other, a model was developed to determine the extent of removal of stormwater pollutants over the length of the wetland. The results from this model complimented the data collected from the field. Improvements, such as increased amounts of vegetation were recommended for the wetlands with the aim of increasing the effectiveness. Further investigations into the wetlands will allow for better understanding of the wetland's performance.

Atomistic analysis of nano/micro biosensors

  • Chen, James;Lee, James D.
    • Interaction and multiscale mechanics
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    • v.3 no.2
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    • pp.111-121
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    • 2010
  • Dynamic analysis of nano/micro bio-sensors based on a multiscale atomistic/continuum theory is introduced. We use a generalized atomistic finite element method (GAFEM) to analyze a bio-sensor which has $3{\times}N_a{\times}N_p$ degrees of freedom, where $N_p$ is the number of representative unit cells and $N_a$ is the number of atoms per unit cell. The stiffness matrix is derived from interatomic potential between pairs of atoms. This work contains two studies: (1) the resonance analysis of nano bio-sensors with different amount of target analyte and (2) the dependence of resonance frequency on finite element mesh. We also examine the Courant-Friedrichs-Lewy (CFL) condition based on the highest resonance frequency. The CFL condition is the criterion for the time step used in the dynamic analysis by GAFEM. Our studies can be utilized to predict the performance of micro/nano bio-sensors from atomistic perspective.

A Fast Poisson Solver of Second-Order Accuracy for Isolated Systems in Three-Dimensional Cartesian and Cylindrical Coordinates

  • Moon, Sanghyuk;Kim, Woong-Tae;Ostriker, Eve C.
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.1
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    • pp.46.1-46.1
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    • 2019
  • We present an accurate and efficient method to calculate the gravitational potential of an isolated system in three-dimensional Cartesian and cylindrical coordinates subject to vacuum (open) boundary conditions. Our method consists of two parts: an interior solver and a boundary solver. The interior solver adopts an eigenfunction expansion method together with a tridiagonal matrix solver to solve the Poisson equation subject to the zero boundary condition. The boundary solver employs James's method to calculate the boundary potential due to the screening charges required to keep the zero boundary condition for the interior solver. A full computation of gravitational potential requires running the interior solver twice and the boundary solver once. We develop a method to compute the discrete Green's function in cylindrical coordinates, which is an integral part of the James algorithm to maintain second-order accuracy. We implement our method in the {\tt Athena++} magnetohydrodynamics code, and perform various tests to check that our solver is second-order accurate and exhibits good parallel performance.

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Tracing the first galaxies with the James Webb Space Telescope

  • Tacchella, Sandro
    • The Bulletin of The Korean Astronomical Society
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    • v.46 no.2
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    • pp.41.2-41.2
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    • 2021
  • I will start with presenting new results on the stellar populations of galaxies at a redshift of z=9-11, when the universe was only a few hundred million years old. By combining Hubble Space Telescope observations with Spitzer imaging data, I will show how challenging it is currently to measure basic physical properties of these objects such as star-formation rates, stellar masses and stellar ages. In particular, the current measurements greatly depend on the assumptions (priors) for the spectral energy distribution modeling. Finally, I will discuss how the James Webb Space Telescope (JWST) will revolutionize this field next year and allow us to probe and characterize the first generation of galaxies in much greater detail. Specifically, I will present an overview of the JWST Advanced Deep Extragalactic Survey (JADES), a joint program of the JWST/NIRCam and NIRSpec Guaranteed Time Observations (GTO) teams involving 950 hours of observation.

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James Joyce's 'The Dead' Revisited

  • Kim, Donguk
    • Journal of English Language & Literature
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    • v.55 no.3
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    • pp.429-440
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    • 2009
  • This paper does not follow the well-known critical practice of Charles Perke, Edward Brandabur and Phillip Herring who, regarding The Dead, James Joyce s earliest masterpiece, as the conclusion of Dubliners, classify Gabriel as one of the dead. Instead it concurs with such critics as William York Tindal, Kenneth Burke and Allen Tate who, interpreting The Dead as a story of Gabriel s spiritual maturation, discuss the famous snow vision at the end of the story as a signifier of his rebirth experience. A new reading of The Dead, which is the aim of this paper, examines the very processes which produce both form and content, thereby demonstrating that The Dead is a story of Gabriel s spiritual growth and that the supreme snow vision is prepared for his spirit which progresses towards a richer synthesis of life and death, a higher altitude of flight and wider horizons.

아 ㆍ태평양지역의 석유개발비용 전망

  • Korea Petroleum Association
    • Korea Petroleum Association Journal
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    • no.12 s.46
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    • pp.89-103
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    • 1984
  • 이 자료는 지난 9월 16~19일, 호주의 멜버른시에서 열렸던 84년도 태평양지역석유회의(Petro Pacific'84)에서 Chase Manhattan Bank. N. A.의 부회장인 JAMES H. CAREY씨가 발표한 내용을 발췌, 번역한 것이다. (편집자 주)

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