1,360 research outputs found

    An Initial Assessment of Remote Access Computer Laboratories for IS Education: A Multiple Case Study

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    New technologies are allowing universities and colleges to create remotely accessible, server-based laboratories that support the teaching of server-based software application development. However, the organizational and technical issues associated with implementing these servers often compromise the pedagogical potential of introducing server-based technologies into the classroom. The purpose of this paper is to make an initial assessment of the organizational and technical issues associated with using server-based, remote access computer labs in an academic or IT training environment. Given the investigative nature of this research, a multiple case study method is used including scripted interviews with eighteen leaders in IS education and IT training. An analysis of these cases suggests six categories of issues: (1) organizational issues with lab setup and administration, (2) technical issues with lab setup and administration, (3) cost issues related to faculty, (4) student requirements for the lab, (5) faculty/instructor requirements for the lab, and (6) employer requirements for the lab. We conclude that the major challenge in deploying a remote access computer laboratory is the development of an institutional environment where IT staff and IS faculty work together to design, implement and administer the technologies

    Computer Lab Technology to Support Information Systems Programs

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    For a number of years the Annual UCLA Survey of Business School Computer Usage (begun in 1984, published in 1985) benchmarked information technology assets available to business school students. The survey was cosponsored by the AACSB for a number of years and was used by schools of business to judge the level of technology that supported students. The last of these surveys was in 1999. The need to document a broad sample of current information technology available to students is as strong today as it has been in the past. The difference today is in the types of technology used and the programmatic goals supported by the technology. The UCLA survey of computer resources focused on computers in open labs, staffing for student labs, dollars spent per student, and similar measures. Today a focus is needed that describes the types of resources used and staffing to assist students and faculty in specialized circumstances. The survey developed here will address the information technology needs for skills outlined in the IS2002 model curriculum

    Inert strength measurement on silica soaked at 250°C in liquid water and water vapour

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    The effect of water soaking and heat-treatment in saturated water vapour at 250°C for 192 h on the strength of silica glass is studied. Bending strength meaurements in liquid nitrogen showed a clear increase of the inert strength for heat-treated specimens over that of the untreated material. The increase in strength is interpreted as the consequence of water diffusion into exposed surfaces of the test specimen, which results in swelling of the glass and shielding of cracks, present in the surface of the glass. Experimental results are compared with theoretical predictions

    Evaluation of crack-terminating angles in heat-treated silica DCDC-specimens

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    Cracks terminating at free surfaces are affected by local stresses in the surface region. Under residual compression, the crack front must retard and under residual tensile stresses advance, both compared with the crack contour in the absence of stresses. This effect can be used for an estimation of residual surface stresses in silica generated during the silica/water reaction and caused by volume swelling. A strong shielding stress intensity factor of about -2.5 MPam\sqrt{m} was found for DCDC specimen heat-treated for 192h at 250°C in water. This result is a clear indication for compressive stresses developing in the water diffusion zone at the surface

    Evolution of microstructure and mechanical properties in gas tungsten arc welded dual-phase Fe50Mn30Co10Cr10 high entropy alloy

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    Funding Information: JPO acknowledges the funding by national funds from FCT - Fundação para a Ciência e a Tecnologia , I.P., in the scope of the projects LA/P/0037/2020 , UIDP/50025/2020 and UIDB/50025/2020 of the Associate Laboratory Institute of Nanostructures, Nanomodelling and Nanofabrication – i3N. Funding Information: JGL, JS and JPO acknowledge Fundação para a Ciência e a Tecnologia ( FCT - MCTES ) for its financial support via the project UID/00667/2020 (UNIDEMI). Funding Information: JS acknowledges the China Scholarship Council for funding the Ph.D. grant (CSC NO. 201808320394 ). Funding Information: JGL acknowledges FCT – MCTES for funding the Ph.D. grant 2020.07350. BD . Publisher Copyright: © 2023 The AuthorsIn recent years, high entropy alloys (HEAs) have been shown to be promising alternatives to common engineering alloys, depending on their composition and thermomechanical processing. Up to now, several works aimed at improving the mechanical properties and discovering different HEAs given the extremely large compositional possibilities made available by the multicomponent approach associated to these materials. Their processability, however, is an important topic that must be studied. Welding is a key manufacturing technique that will eventually be applied to HEAs. Thus, there is a need to evaluate the microstructure and property changes induced by the weld thermal cycles, to assess the suitability of certain welding process/HEAs combinations for possible industrial applications. In the present work, Gas Tungsten Arc Welding (GTAW) was used to achieve defect-free joints based on a novel transformation induced plasticity (TRIP) Fe50Mn30Co10Cr10 HEA. The microstructure and mechanical behavior of the joints were assessed by means of optical and electron microscopy, synchrotron X-ray diffraction, thermodynamical calculations, microhardness mapping and tensile testing. Overall, an excellent mechanical performance was obtained on the resulting joints, opening the door for their adoption in real-life applications.publishersversionpublishe

    Arnol'd Tongues and Quantum Accelerator Modes

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    The stable periodic orbits of an area-preserving map on the 2-torus, which is formally a variant of the Standard Map, have been shown to explain the quantum accelerator modes that were discovered in experiments with laser-cooled atoms. We show that their parametric dependence exhibits Arnol'd-like tongues and perform a perturbative analysis of such structures. We thus explain the arithmetical organisation of the accelerator modes and discuss experimental implications thereof.Comment: 20 pages, 6 encapsulated postscript figure

    Diffusion in normal and critical transient chaos

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    In this paper we investigate deterministic diffusion in systems which are spatially extended in certain directions but are restricted in size and open in other directions, consequently particles can escape. We introduce besides the diffusion coefficient D on the chaotic repeller a coefficient D^{\hat D} which measures the broadening of the distribution of trajectories during the transient chaotic motion. Both coefficients are explicitly computed for one-dimensional models, and they are found to be different in most cases. We show furthermore that a jump develops in both of the coefficients for most of the initial distributions when we approach the critical borderline where the escape rate equals the Liapunov exponent of a periodic orbit.Comment: 4 pages Revtex file in twocolumn format with 2 included postscript figure

    In-situ hot forging directed energy deposition-arc of CuAl8 alloy

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    Funding Information: Authors acknowledge the Portuguese Fundação para a Ciência e a Tecnologia ( FCT - MCTES ) for its financial support via the project UID/EMS/00667/2019 (UNIDEMI). VD acknowledges Portuguese Fundação para a Ciência e a Tecnologia ( FCT - MCTES ) for funding the PhD grant SFRH/BD/139454/2018 . TAR acknowledges Portuguese Fundação para a Ciência e a Tecnologia ( FCT - MCTES ) for funding the PhD grant SFRH/BD/144202/2019 . Funding of CENIMAT/i3N by national funds through the Portuguese Fundação para a Ciência e a Tecnologia, I.P., within the scope of Multiannual Financing of R&D Units , reference UIDB/50025/2020–2023 is also acknowledge. This activity has received funding from the European Institute of Innovation and Technology (EIT) Raw Materials through the project Smart WAAM: Microstructural Engineering and Integrated Non-Destructive Testing. This body of the European Union receives support from the European Union's Horizon 2020 research and innovation programme. Parts of this research were carried out at PETRA III at DESY, a member of the Helmholtz Association. The research leading to this result has been supported by the project CALIPSOplus under the Grant Agreement 730872 from the EU Framework Programme for Research and Innovation HORIZON 2020 . This project has received funding from the EU-H2020 research and innovation programme under grant agreement No 654360 having benefitted from the access provided by PETRA III at DESY in Hamburg, Germany within the framework of the NFFA-Europe Transnational Access Activity. The authors acknowledge support by OCAS NV and GUARENTEED via Joachim Antonissen. Funding Information: Authors acknowledge the Portuguese Fundação para a Ciência e a Tecnologia (FCT - MCTES) for its financial support via the project UID/EMS/00667/2019 (UNIDEMI). VD acknowledges Portuguese Fundação para a Ciência e a Tecnologia (FCT - MCTES) for funding the PhD grant SFRH/BD/139454/2018. TAR acknowledges Portuguese Fundação para a Ciência e a Tecnologia (FCT - MCTES) for funding the PhD grant SFRH/BD/144202/2019. Funding of CENIMAT/i3N by national funds through the Portuguese Fundação para a Ciência e a Tecnologia, I.P. within the scope of Multiannual Financing of R&D Units, reference UIDB/50025/2020–2023 is also acknowledge. This activity has received funding from the European Institute of Innovation and Technology (EIT) Raw Materials through the project Smart WAAM: Microstructural Engineering and Integrated Non-Destructive Testing. This body of the European Union receives support from the European Union's Horizon 2020 research and innovation programme. Parts of this research were carried out at PETRA III at DESY, a member of the Helmholtz Association. The research leading to this result has been supported by the project CALIPSOplus under the Grant Agreement 730872 from the EU Framework Programme for Research and Innovation HORIZON 2020. This project has received funding from the EU-H2020 research and innovation programme under grant agreement No 654360 having benefitted from the access provided by PETRA III at DESY in Hamburg, Germany within the framework of the NFFA-Europe Transnational Access Activity. The authors acknowledge support by OCAS NV and GUARENTEED via Joachim Antonissen. Remark: The supplementary material is temporarily available in the Drive folder here: https://drive.google.com/drive/folders/1SFFlhJlmL5p3IkQis8cB6UVWva3wozGi?usp=sharing. Publisher Copyright: © 2022 Elsevier B.V.CuAl8 alloy finds applications in industrial components, where a good anti-corrosion and anti-wearing properties are required. The alloy has a medium strength and a good toughness with an elongation to fracture at room temperature of about 40%. Additionally, it has a good electrical conductivity, though lower than that of pure Al or pure Cu. Despite these characteristics, additive manufacturing of the CuAl8 alloy was not yet reported. In this work, the direct energy deposition-arc (DED-arc) with and without in-situ hot forging was used to determine the microstructure evolution and mechanical properties. No internal defects were seen on the parts produced. Hot forging combined with DED-arc was seen to reduce and homogenize the grain size, improve mechanical strength and isotropy of mechanical properties. Moreover, the use of this novel DED-arc variant was seen to reduce the magnitude of residual stresses throughout the fabricated part. We highlight that this alloy can be processed by DED-arc, and the hot forging operation concomitant with the material deposition has beneficial effects on the microstructure refinement and homogenization.publishersversionpublishe

    Estimation of swelling stresses from crack-terminating angles

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    Cracks terminating at free surfaces are affected by local stresses in the surface region. The crack front retards under residual compressive stresses compared with the crack contour in the absence of stresses. This effect had been used in [1] for identifying compression in the surface of chemically toughened and ion-exchanged soda-lime glass surfaces. In [2] the same effect was proven for swelling stresses due to the silica/water reaction. In the present report, the stresses in the surface layers are predicted based on results for soda-lime glass. For silica heattreated in humid environments, compressive stresses in the order of about -130 MPa to -170 MPa are obtained
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