2,520 research outputs found

    Bis(2-amino-1,3-benzothia­zol-3-ium) bis­(7-oxabicyclo­[2.2.1]heptane-2,3-dicarboxyl­ato)cadmate hexa­hydrate

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    In the structure of the title complex, (C7H7N2S)2[Cd(C8H8O5)2]·6H2O, the CdII atom is located on an inversion center and is O,O′,O′′-chelated by two symmetry-related 7-oxabicyclo­[2.2.1]heptane-2,3-dicarboxyl­ate ligands in a distorted octa­hedral geometry. The 2-amino­benzothia­zolium cation links with the Cd complex anion via N—H⋯O hydrogen bonding. Extensive O—H⋯O and N—H⋯O hydrogen bonds involving lattice water mol­ecules occur in the crystal structure

    Underpass clearance checking in highway widening projects using digital twins

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    Main road widening can reduce the clearance of the low-level underpass road, restricting the passage of vehicles and leading to collisions with structures. Therefore, checking the clearance of the underpass road effectively should be considered at the design stage. This paper describes a digital twin approach for checking the clearance of underpass roads in highway widening projects using online map data. The underpass road digital twin and BIM model of the newly widened road based on the existing main road digital twin are created to assist the clearance check and redesign. The proposed method presented a cost-effective clearance check for underpass roads in road widening design without field surveys and was successfully implemented in an underpass road in the UK. In future research, more digital twin methods for overpasses, bridges, tunnels, and traffic safety facilities should be employed comprehensively to assist more road widening applications

    Building demolition estimation in urban road widening projects using as-is BIM models

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    Building demolition caused by urban road widening projects can lead to engineering, economic, and environmental issues and should be planned at the design stage. Based on as-is BIM, this paper proposes a method to estimate the building demolition caused by urban road widening using online map data and statistics on government websites. The as-is BIM models of the existing old road and its surrounding buildings are created, and the BIM models of the newly widened road are built based on the as-is BIM models considering road components in accordance with road engineering expressions to assist building demolition estimation using clash detection. This paper presents a cost-effective building demolition estimation in urban road widening projects without field surveys. It was tested on the M4 Motorway project in London. It has been proved to be a very practical approach to facilitate urban road planning and decision making

    Sustainable road alignment planning in the built environment based on the MCDM-GIS method

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    Sustainable road planning in the cities' built-up areas strives to meet traffic demands of society within limited spaces available for construction and various constraints in the built environment considering engineering, traffic, economic, social, and environmental factors. Unlike rural areas, road planning in the built environment can be significantly influenced by the surroundings, such as existing buildings, road network, and land use, and should consider noise and air pollution impact on residents. In addition, road width and road widening are significant factors for road alignment planning. Based on the MCDM-GIS method, the least-cost wide path algorithm is employed for sustainable road alignment planning in the built environment, considering building demolition and land use, traffic congestion, noise impact, air pollution impact, and construction costs. Road width, new road construction, and existing road widening are considered simultaneously. Several methods are proposed to digitalise and parse various sustainable factors into understandable expressions for road alignment planning. Forbidden areas and road buffer areas for road widening are defined. The proposed method is implemented in road planning in Dartford, Kent County, UK. Sustainable factors with different weights can generate various road alignments from different perspectives, and road widths can significantly and locally influence road alignments

    Two Case Reports of Familial Chylomicronemia Syndrome

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    Familial chylomicronemia is a rare autosomal recessive disorder which is also called Hyperlipoproteinemia type I. Here we report two cases with this rare disorder that were admitted to our hospital in recent years

    Symmetry of Dirac Equation and Corresponding Phenomenology

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    It has been suggested that the high symmetries in the Schr\"odinger equation with the Coulomb or harmonic oscillator potentials may remain in the corresponding relativistic Dirac equation. If the principle is correct, in the Dirac equation the potential should have a form as (1+β)2V(r){(1+\beta)\over 2}V(r) where V(r)V(r) is e2r{-e^2\over r} for hydrogen atom and κr2\kappa r^2 for harmonic oscillator. However, in the case of hydrogen atom, by this combination the spin-orbit coupling term would not exist and it is inconsistent with the observational spectra of hydrogen atom, so that the symmetry of SO(4) must reduce into SU(2). The governing mechanisms QED and QCD which induce potential are vector-like theories, so at the leading order only vector potential exists. However, the higher order effects may cause a scalar fraction. In this work, we show that for QED, the symmetry restoration is very small and some discussions on the symmetry breaking are made. At the end, we briefly discuss the QCD case and indicate that the situation for QCD is much more complicated and interesting.Comment: 15pages, 3 figures, accepted by International Journal of Modern Physics

    Digital technology for quality management in construction:A review and future research directions

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    Significant developments in digital technologies can potentially provide managers and engineers with the ability to improve the quality of the construction industry. Acknowledging the current and future use of digital technologies in construction quality management (CQM), we address the following research question: What developments in digital technologies can be used to improve quality in the construction industry? In addressing this research question, a systematic review approach is used to examine the studies that have been used for the management of quality in the construction industry. This review indicates that there is a need for digital technology-based quality management to be: (1) enhance defect management for concealed work, (2) enhance pre-construction defects prevention as well as post-completion product function testing, and (3) research on construction compliance inspection as a direction. We suggest that future research focus on quality culture development, advanced data analytics, and behavioral quality assessment
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