37 research outputs found

    Construction project change: Investigating cost and benefits

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    Cost overrun of projects is common in the construction industry. Changes to the original design and to the scope of works during the design development and construction phases contribute significantly to overall cost overrun of construction projects. However, scholars argue that change is inevitable, and some changes add value to the project. Therefore, it can be argued that the overrun of the initial construction cost through the changes made to the project may be insignificant compared to the reductions in life-cycle cost and whole life value of resultant built environments. Early research is presented here of a wider project seeking to evaluate the costs and value of proactive changes made during the construction phase with the intention to add value to the whole life of the project. Change control accounts and other related documentary evidence of two construction projects were investigated to identify changes made to the projects during the construction phase, and cost of those changes. Semi-structured interviews with quantity surveyors and project managers involved in those projects were conducted to enrich this documentary data. Analysis explored the contribution of proactive changes made with the intention to increase whole-life value to the overall cost overrun of construction projects, and clients’ understanding and willingness to pay for such changes. The next phase of this research will investigate the whole life value gained by the clients from these changes. Ultimately, this research aims to increase both clients and project managers understanding of cost and value of changes during the construction phase, with due consideration of the whole life cycle of construction projects

    Healthcare designers’ use of prescriptive and performance-based approaches

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    In the UK, healthcare built environment design is guided by a series of long-established design standards and guidance issued by the Department of Health. More recently, healthcare design focus has broadened to encompass new approaches, supported by large bodies of credible research evidence. It is therefore timely to rethink how healthcare design standards and guidance should be best expressed to suit ‘designerly ways’ of using evidence, to improve their use and effectiveness in practice. This research explored how designers use performance and prescriptive approaches during the healthcare design process. Three in-depth healthcare built environment case studies were used to explore how designers employed such approaches during the design of selected exemplar design elements. Results show that design elements in the pre and conceptual design phases significantly employed performance-based approaches, and due to project-unique circumstances, prescriptive solutions were often significantly modified based on performance criteria. For design elements in the detailed and technical design phases, there was a significant use of solutions based on prescriptive approaches, whilst performance-based criteria were used to evaluate design solutions. This research proposes a performance-based, specification-driven healthcare design with supplementary prescriptive specifications provided for optimum healthcare environment design

    Does evidence based design for healthcare built environments limit creativity?

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    Research into therapeutic built environments and Evidence Based Design (EBD) has increased during the past three decades and the concept more readily adopted in practice. However, some practitioners believe that, as with any approach that builds on previous experiences to develop standards and guidelines, EBD could limit creativity. Given that creativity is often regarded as a major source of competitive advantage for a design, if EBD is seen as a barrier to creativity this may hinder its acceptance and application. The extent to which EBD could limit creativity during the design process is explored through a literature review. The findings suggest that only a smaller segment of evidence-based information, which relates to concept development, would affect creativity. Such information could foster information-driven design strategy and result in a lower level of creativity. However, properly implemented EBD strategies should not limit creativity since expert designers in EBD would use their knowledge (of therapeutic evidence) and expertness in the design process and need not follow and information driven strategy

    First Measurement of the EMC Effect in 10^{10}B and 11^{11}B

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    The nuclear dependence of the inclusive inelastic electron scattering cross section (the EMC effect) has been measured for the first time in 10^{10}B and 11^{11}B. Previous measurements of the EMC effect in A12A \leq 12 nuclei showed an unexpected nuclear dependence; 10^{10}B and 11^{11}B were measured to explore the EMC effect in this region in more detail. Results are presented for 9^9Be, 10^{10}B, 11^{11}B, and 12^{12}C at an incident beam energy of 10.6~GeV. The EMC effect in the boron isotopes was found to be similar to that for 9^9Be and 12^{12}C, yielding almost no nuclear dependence in the EMC effect in the range A=412A=4-12. This represents important, new data supporting the hypothesis that the EMC effect depends primarily on the local nuclear environment due to the cluster structure of these nuclei.Comment: Submitted to PR

    The present and future of QCD

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    This White Paper presents an overview of the current status and future perspective of QCD research, based on the community inputs and scientific conclusions from the 2022 Hot and Cold QCD Town Meeting. We present the progress made in the last decade toward a deep understanding of both the fundamental structure of the sub-atomic matter of nucleon and nucleus in cold QCD, and the hot QCD matter in heavy ion collisions. We identify key questions of QCD research and plausible paths to obtaining answers to those questions in the near future, hence defining priorities of our research over the coming decades

    Probing high-momentum protons and neutrons in neutron-rich nuclei

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    The atomic nucleus is one of the densest and most complex quantum-mechanical systems in nature. Nuclei account for nearly all the mass of the visible Universe. The properties of individual nucleons (protons and neutrons) in nuclei can be probed by scattering a high-energy particle from the nucleus and detecting this particle after it scatters, often also detecting an additional knocked-out proton. Analysis of electron- and proton-scattering experiments suggests that some nucleons in nuclei form close-proximity neutron-proton pairs1-12 with high nucleon momentum, greater than the nuclear Fermi momentum. However, how excess neutrons in neutron-rich nuclei form such close-proximity pairs remains unclear. Here we measure protons and, for the first time, neutrons knocked out of medium-to-heavy nuclei by high-energy electrons and show that the fraction of high-momentum protons increases markedly with the neutron excess in the nucleus, whereas the fraction of high-momentum neutrons decreases slightly. This effect is surprising because in the classical nuclear shell model, protons and neutrons obey Fermi statistics, have little correlation and mostly fill independent energy shells. These high-momentum nucleons in neutron-rich nuclei are important for understanding nuclear parton distribution functions (the partial momentum distribution of the constituents of the nucleon) and changes in the quark distributions of nucleons bound in nuclei (the EMC effect)1,13,14. They are also relevant for the interpretation of neutrino-oscillation measurements15 and understanding of neutron-rich systems such as neutron stars3,16

    The present and future of QCD

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    This White Paper presents an overview of the current status and future perspective of QCD research, based on the community inputs and scientific conclusions from the 2022 Hot and Cold QCD Town Meeting. We present the progress made in the last decade toward a deep understanding of both the fundamental structure of the sub-atomic matter of nucleon and nucleus in cold QCD, and the hot QCD matter in heavy ion collisions. We identify key questions of QCD research and plausible paths to obtaining answers to those questions in the near future, hence defining priorities of our research over the coming decades

    Strong Interaction Physics at the Luminosity Frontier with 22 GeV Electrons at Jefferson Lab

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    This document presents the initial scientific case for upgrading the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab (JLab) to 22 GeV. It is the result of a community effort, incorporating insights from a series of workshops conducted between March 2022 and April 2023. With a track record of over 25 years in delivering the world's most intense and precise multi-GeV electron beams, CEBAF's potential for a higher energy upgrade presents a unique opportunity for an innovative nuclear physics program, which seamlessly integrates a rich historical background with a promising future. The proposed physics program encompass a diverse range of investigations centered around the nonperturbative dynamics inherent in hadron structure and the exploration of strongly interacting systems. It builds upon the exceptional capabilities of CEBAF in high-luminosity operations, the availability of existing or planned Hall equipment, and recent advancements in accelerator technology. The proposed program cover various scientific topics, including Hadron Spectroscopy, Partonic Structure and Spin, Hadronization and Transverse Momentum, Spatial Structure, Mechanical Properties, Form Factors and Emergent Hadron Mass, Hadron-Quark Transition, and Nuclear Dynamics at Extreme Conditions, as well as QCD Confinement and Fundamental Symmetries. Each topic highlights the key measurements achievable at a 22 GeV CEBAF accelerator. Furthermore, this document outlines the significant physics outcomes and unique aspects of these programs that distinguish them from other existing or planned facilities. In summary, this document provides an exciting rationale for the energy upgrade of CEBAF to 22 GeV, outlining the transformative scientific potential that lies within reach, and the remarkable opportunities it offers for advancing our understanding of hadron physics and related fundamental phenomena.Comment: Updates to the list of authors; Preprint number changed from theory to experiment; Updates to sections 4 and 6, including additional figure

    Strong interaction physics at the luminosity frontier with 22 GeV electrons at Jefferson Lab

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    This document presents the initial scientific case for upgrading the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab (JLab) to 22 GeV. It is the result of a community effort, incorporating insights from a series of workshops conducted between March 2022 and April 2023. With a track record of over 25 years in delivering the world's most intense and precise multi-GeV electron beams, CEBAF's potential for a higher energy upgrade presents a unique opportunity for an innovative nuclear physics program, which seamlessly integrates a rich historical background with a promising future. The proposed physics program encompass a diverse range of investigations centered around the nonperturbative dynamics inherent in hadron structure and the exploration of strongly interacting systems. It builds upon the exceptional capabilities of CEBAF in high-luminosity operations, the availability of existing or planned Hall equipment, and recent advancements in accelerator technology. The proposed program cover various scientific topics, including Hadron Spectroscopy, Partonic Structure and Spin, Hadronization and Transverse Momentum, Spatial Structure, Mechanical Properties, Form Factors and Emergent Hadron Mass, Hadron-Quark Transition, and Nuclear Dynamics at Extreme Conditions, as well as QCD Confinement and Fundamental Symmetries. Each topic highlights the key measurements achievable at a 22 GeV CEBAF accelerator. Furthermore, this document outlines the significant physics outcomes and unique aspects of these programs that distinguish them from other existing or planned facilities. In summary, this document provides an exciting rationale for the energy upgrade of CEBAF to 22 GeV, outlining the transformative scientific potential that lies within reach, and the remarkable opportunities it offers for advancing our understanding of hadron physics and related fundamental phenomena

    The present and future of QCD

    Get PDF
    This White Paper presents an overview of the current status and future perspective of QCD research, based on the community inputs and scientific conclusions from the 2022 Hot and Cold QCD Town Meeting. We present the progress made in the last decade toward a deep understanding of both the fundamental structure of the sub-atomic matter of nucleon and nucleus in cold QCD, and the hot QCD matter in heavy ion collisions. We identify key questions of QCD research and plausible paths to obtaining answers to those questions in the near future, hence defining priorities of our research over the coming decades
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