605 research outputs found

    Probabilistic Analysis of Strength of Structural Concrete for Post-Code Buildings in Developing Countries

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    Code compliance and quality construction remain a point of interest for developing countries. For structural vulnerability studies on reinforced concrete buildings, researchers usually adopt random strength parameters to represent the compressive strength of concrete for various structural members. This matter becomes a challenge if researchers are dealing to quantify the structural response of code-compliant buildings. Since the research on the response of code-compliant buildings is limited hence this paper aims at data collection and presenting the probabilistic trends in compressive strength variation of structural concrete being used or has been used in multiple projects of the federal capital city of Pakistan for code-compliant buildings. The data has been collected from well-reputed academic and commercial testing labs in the area for past 10 years (the timeline after implementation of BCP 2007). Compressive strength testing records of concrete cylinders for 28 days strength have been sorted for different structural members i.e., beams, columns, shear walls, slabs and footings separately. From the selected data, histograms have been plotted for each member category and mean values with standard deviations have been highlighted. Obtained results are further compared with anticipated design compressive strengths which were obtained from different tagged reports, design offices and resident engineers of the sites. The produced results would lead to true representation of structural strength of concrete for code-compliant buildings, to be further studied for structural vulnerability and risk assessments of the desired areas in developing countries

    Experimental investigation of performance, emissions and tribological characteristics of B20 blend from cottonseed and palm oil biodiesels

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    Reserves of fossil fuel are being depleted, and its use to generate energy also affects the environment. Sustainable and clean energy sources, therefore, need to be produced to meet the demands. In this research, combined blended fuels were produced from cottonseed and palm oil methyl esters with petroleum diesel fuel. To achieve the benefits of palm oil biodiesel (high calorific value) and cottonseed oil biodiesel (low kinematic viscosity and acid value), the combined biodiesel blend (C05P15, C10P10, and C15P05) has been tested to assess their effect on engine performance, emissions, and tribological properties. The physicochemical properties of all fuels were measured following ASTM D6751 standard. A single-cylinder, 4-stroke, and the natural aspiration diesel engine were used for engine testing. The experimental results showed that all combined blended fuels have low brake thermal efficiency and emitted fewer hydrocarbons, carbon monoxide, and smoke opacity apart from nitrogen oxides compared with petroleum diesel fuel. Based on results, the combined blended fuel can be used as a substitute fuel in diesel engines without any engine modifications

    Evolution of pulmonary hypertension in interstitial lung disease: a journey through past, present, and future

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    Interstitial lung diseases (ILD) are a spectrum of disorders often complicated by pulmonary hypertension (PH) in its course. The pathophysiologic mechanism of WHO group 3 PH is different to other forms of PH. The advent of PH is a harbinger for adverse events like mortality and morbidity, implying that the PH component of disease expedites deteriorated clinical outcomes. In fact, WHO group 3 PH due to ILD has the worse prognosis among all groups of PH. Hence, early detection of PH by a comprehensive screening method is paramount. Given considerable overlap in clinical manifestations between ILD and PH, early detection of PH is often elusive. Despite, the treatment of PH due to ILD has been frustrating until recently. Clinical trials utilizing PAH-specific pulmonary vasodilators have been ongoing for years without desired results. Eventually, the INCREASE study (2018) demonstrated beneficial effect of inhaled Treprostinil to treat PH in ILD. In view of this pioneering development, a paradigm shift in clinical approach to this disease phenotype is happening. There is a renewed vigor to develop a well validated screening tool for early detection and management. Currently inhaled Treprostinil is the only FDA approved therapy to treat this phenotype, but emergence of a therapy has opened a plethora of research toward new drug developments. Regardless of all these recent developments, the overall outlook still remains grim in this condition. This review article dwells on the current state of knowledge of pre-capillary PH due to ILD, especially its diagnosis and management, the recent progresses, and future evolutions in this field

    Measurements of fiducial and differential cross sections for Higgs boson production in the diphoton decay channel at s√=8 TeV with ATLAS

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    Measurements of fiducial and differential cross sections are presented for Higgs boson production in proton-proton collisions at a centre-of-mass energy of s√=8 TeV. The analysis is performed in the H → γγ decay channel using 20.3 fb−1 of data recorded by the ATLAS experiment at the CERN Large Hadron Collider. The signal is extracted using a fit to the diphoton invariant mass spectrum assuming that the width of the resonance is much smaller than the experimental resolution. The signal yields are corrected for the effects of detector inefficiency and resolution. The pp → H → γγ fiducial cross section is measured to be 43.2 ±9.4(stat.) − 2.9 + 3.2 (syst.) ±1.2(lumi)fb for a Higgs boson of mass 125.4GeV decaying to two isolated photons that have transverse momentum greater than 35% and 25% of the diphoton invariant mass and each with absolute pseudorapidity less than 2.37. Four additional fiducial cross sections and two cross-section limits are presented in phase space regions that test the theoretical modelling of different Higgs boson production mechanisms, or are sensitive to physics beyond the Standard Model. Differential cross sections are also presented, as a function of variables related to the diphoton kinematics and the jet activity produced in the Higgs boson events. The observed spectra are statistically limited but broadly in line with the theoretical expectations

    Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at s√=8 TeV with the ATLAS detector

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    The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. The search is based on proton-proton collision data at a centre-of-mass energy s√=8 TeV collected in 2012, corresponding to an integrated luminosity of 20 fb−1. No significant excess above the Standard Model expectation is observed. Limits are set on supersymmetric particle masses for various supersymmetric models. Depending on the model, the search excludes gluino masses up to 1.32 TeV and squark masses up to 840 GeV. Limits are also set on the parameters of a minimal universal extra dimension model, excluding a compactification radius of 1/R c = 950 GeV for a cut-off scale times radius (ΛR c) of approximately 30

    Measurement of the production of a W boson in association with a charm quark in pp collisions at √s = 7 TeV with the ATLAS detector

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    The production of a W boson in association with a single charm quark is studied using 4.6 fb−1 of pp collision data at s√ = 7 TeV collected with the ATLAS detector at the Large Hadron Collider. In events in which a W boson decays to an electron or muon, the charm quark is tagged either by its semileptonic decay to a muon or by the presence of a charmed meson. The integrated and differential cross sections as a function of the pseudorapidity of the lepton from the W-boson decay are measured. Results are compared to the predictions of next-to-leading-order QCD calculations obtained from various parton distribution function parameterisations. The ratio of the strange-to-down sea-quark distributions is determined to be 0.96+0.26−0.30 at Q 2 = 1.9 GeV2, which supports the hypothesis of an SU(3)-symmetric composition of the light-quark sea. Additionally, the cross-section ratio σ(W + +c¯¯)/σ(W − + c) is compared to the predictions obtained using parton distribution function parameterisations with different assumptions about the s−s¯¯¯ quark asymmetry
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