203 research outputs found

    Monitoring the strength gain of structural adhesives using the electromechanical impedance technique: An experimental investigation

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    Structural adhesives are employed to externally bond fibre-reinforced polymer (FRP) composites onto concrete structures for repair and strengthening purposes. The strength development of the bond layer is important to ensure the overall performance of the FRP-strengthened system. The non-destructive piezoelectric-based monitoring technique, namely the electromechanical impedance (EMI) technique, is introduced to monitor the strength gain of structural adhesives. In this study, the curing process of the commercially available structural adhesive, Sikadur 330, was monitored using the EMI technique. Throughout the experimental study, the 7-day strength gain of the adhesive was observed from the movement of acquired frequency peaks. The frequency peaks moved noticeably to the right for the first 24 hours. After that, the rate of movement decreased significantly. An empirical equation is established to correlate the tensile strength of the adhesive to the acquired resonance frequency for different curing durations. The current study shows the capability of the EMI technique to monitor the strength gain of structural adhesives, particularly at an early age of curing

    Monitoring the curing process of structural adhesives using the electromechanical impedance technique: A numerical investigation

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    Structural adhesives act as a bonding agent to externally bond fibre-reinforced polymer (FRP) composites onto existing structures for strengthening purposes. The performance of FRP-strengthened systems are therefore affected by the strength and stiffness of the structural adhesive layer. The lead zirconate titanate (PZT)-based electromechanical impedance (EMI) technique was employed in this study to monitor the stiffness development process of structural adhesives. A finite element model was developed to investigate the interaction between the PZT patches and the structural adhesive throughout the curing process. The dynamic elastic modulus of the structural adhesives can be predicted from the simulated EMI signatures. The EMI signatures were compared with experimental results for verification purposes. An empirical equation was established to predict the elastic modulus of structural adhesives from the resonance frequency. The current study can be extended by developing a model that predicts the tensile strength of structural adhesives at different curing durations

    Predicting high-risk patients using the International IGA Nephropathy risk prediction tool: a preliminary single-centre analysis

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    Introduction The International IgA Nephropathy Risk Prediction Tool (IgAN- RPT) has been utilized to predict renal progression up to 5 or 7 years after biopsy via histological and clinical risk factors. We reported the preliminary analysis of the renal outcome of IgAN patients in relation to their predicted risk based on the IgAN-RPT at biopsy. Methods We included 29 biopsy-proven adult IgAN patients diagnosed between 2010 and 2017. The IgAN-RPT predicted risk score at 5 years was calculated for each patient. The primary outcome was the risk of developing a 50% decline in the estimated glomerular filtration rate (eGFR) or end stage renal disease (ESRD) at 5 years after biopsy. Independent Student T-test and chi-square analysis were used to compare the clinical data between groups, while Kaplan-Meier survival analysis was done to compare the predicted and observed outcomes within risk groups using SPSS 26 (2020; IBM Corp., Armonk, NY, USA). Results Our cohort consisted of 13 Chinese, 12 Malay and 4 Indian patients with a mean eGFR of 68.2 (±5.7) at biopsy. The median 5-year IgAN-RPT risk score was 13.12% (IQR: 6.02 to 28.00). 20.7% (n=6) reached the primary outcome. Statistically significant; lower mean serum albumin level [30.5 ± 3.3 versus 38.0 ± 6.9, t=2.571 (27), p= 0.016], higher proportion of not using RAS blocker [100.0% versus 11.5%, χ2 = 10.9 (2), p=0.004] and higher proportion of using immunosuppression at biopsy [36.4% versus 5.9%, χ2 =7.54 (2), p=0.023] were noted among these patients. At this preliminary point, none of the other clinical data was significant, thus no further multivariate analyses were performed. To compare the predicted and observed outcomes within the risk group, a cut-off point of 30% for the predicted risk was determined by calculating the Youden Index of a receiving operating curve plotted between the predicted outcome versus observed outcome at 5 years. Results showed well-separated curves between the two risk groups, indicating a good discriminant ability of the tool among our patients. Conclusions Our study demonstrated the median 5-year 1gAN-RPT risk score among our patients was 13.12% with 20.7% of them reaching the primary outcome. Moreover, a cut-off of 30% IgAN- RPT predicted score could discriminate between high-risk versus low-risk patients to develop ESRD or a 50% decline in eGFR in this population. No conflict of interes

    Search for leptophobic Z ' bosons decaying into four-lepton final states in proton-proton collisions at root s=8 TeV

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    Search for black holes and other new phenomena in high-multiplicity final states in proton-proton collisions at root s=13 TeV

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    Search for heavy resonances decaying into a vector boson and a Higgs boson in final states with charged leptons, neutrinos, and b quarks

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    Search for high-mass diphoton resonances in proton-proton collisions at 13 TeV and combination with 8 TeV search

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    Measurements of differential production cross sections for a Z boson in association with jets in pp collisions at root s=8 TeV

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    Phenomenological MSSM interpretation of CMS searches in pp collisions at √s=7 and 8 TeV

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    Searches for new physics by the CMS collaboration are interpreted in the framework of the phenomenological minimal supersymmetric standard model (pMSSM). The data samples used in this study were collected at root s = 7 and 8 TeV and have integrated luminosities of 5.0 fb(-1) and 19.5 fb(-1), respectively. A global Bayesian analysis is performed, incorporating results from a broad range of CMS supersymmetry searches, as well as constraints from other experiments. Because the pMSSM incorporates several well-motivated assumptions that reduce the 120 parameters of the MSSM to just 19 parameters defined at the electroweak scale, it is possible to assess the results of the study in a relatively straightforward way. Approximately half of the model points in a potentially accessible subspace of the pMSSM are excluded, including all pMSSM model points with a gluino mass below 500 GeV, as well as models with a squark mass less than 300 GeV. Models with chargino and neutralino masses below 200 GeV are disfavored, but no mass range of model points can be ruled out based on the analyses considered. The nonexcluded regions in the pMSSM parameter space are characterized in terms of physical processes and key observables, and implications for future searches are discussed

    Measurement of the azimuthal anisotropy of Y(1S) and Y(2S) mesons in PbPb collisions at √S^{S}NN = 5.02 TeV

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    The second-order Fourier coefficients (υ2_{2}) characterizing the azimuthal distributions of ΄(1S) and ΄(2S) mesons produced in PbPb collisions at sNN\sqrt{s_{NN}} = 5.02 TeV are studied. The ΄mesons are reconstructed in their dimuon decay channel, as measured by the CMS detector. The collected data set corresponds to an integrated luminosity of 1.7 nb−1^{-1}. The scalar product method is used to extract the υ2_{2} coefficients of the azimuthal distributions. Results are reported for the rapidity range |y| < 2.4, in the transverse momentum interval 0 < pT_{T} < 50 GeV/c, and in three centrality ranges of 10–30%, 30–50% and 50–90%. In contrast to the J/ψ mesons, the measured υ2_{2} values for the ΄ mesons are found to be consistent with zero
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