Experimental investigation of the cyclic behaviour of unreinforced masonry spandrels

In unreinforced masonry (URM) walls the vertical piers are connected by horizontal spandrel elements. Numerical simulations have shown that spandrels influence significantly the global wall behaviour under seismic loading. Despite their importance, experimental data on the cyclic behaviour of these spandrels is very scarce. The lack of experimental data prevented in the past the validation of numerical and mechanical models regarding the cyclic behaviour of masonry spandrels. For this reason a research program was initiated in which the cyclic behaviour of masonry spandrels was investigated experimentally and numerically. Within this program different configurations of masonry spandrels were tested under quasi-static monotonic and cyclic loading. The spandrel configurations that were investigated included pure masonry spandrels and masonry spandrels which also comprise a reinforced concrete (RC) beam or slab. The latter represents spandrels in newer masonry buildings with RC slabs or RC ring beams while the former can be found in older masonry buildings. This paper presents preliminary results of the experimental program as well as some selected results of the accompanying numerical study

Effect of Coating of Earthed Enclosure and Multi-Contaminating Particles on Breakdown Voltage inside Gas Insulated Bus Duct

Metallic particle contamination is one of the areas of insulation design that are considered critical. This paper demonstrates the control of metallic particles in gas insulated bus duct (GIBD) by using dielectric coating on the inside surface of the outer enclosure of a coaxial electrode system. Several models of GIBD with single and multi-contaminating particles will be studied. In this paper, the Finite Elements Method (FEM) is used to evaluate the electric field distribution on and around single and multi-contaminating wire particles which in contact with dielectric coating of earthed enclosure inside GIBD. The effect of changing the length and the radius of middle particle for multi-contaminating particles on the electric field values are studied. Breakdown Voltage calculations for gas mixtures with single and multi-contaminating wire particles are studied. The effects of gas pressure on the breakdown voltage for various fractional concentrations of SF6-gas mixtures with and without particle contamination and also with and without coating of earthed enclosure are studied. The optimum gas mixture which gives higher dielectric strength with lower cost is also determined. The effect of coating thickness of earthed enclosure on the breakdown voltage for various fractional concentrations of SF6-gas mixtures is also studied. Finally, the effect of length and hemi-spherical radius of multi-contaminating particles on the breakdown voltage with various SF6-gas mixtures and varying gas pressure one time and another time with fixed pressure are studied.DOI:http://dx.doi.org/10.11591/ijece.v4i4.569

Prediction of preterm delivery in symptomatic women using PAMG‐1, fetal fibronectin and phIGFBP‐1 tests: systematic review and meta‐analysis

Objective To assess the accuracy of placental alpha microglobulin‐1 (PAMG‐1), fetal fibronectin (fFN) and phosphorylated insulin‐like growth factor‐binding protein‐1 (phIGFBP‐1) tests in predicting spontaneous preterm birth (sPTB) within 7 days of testing in women with symptoms of preterm labor, through a systematic review and meta‐analysis of the literature. The test performance of each biomarker was also assessed according to pretest probability of sPTB ≤ 7 days. Methods The Cochrane, MEDLINE, PubMed and ResearchGate bibliographic databases were searched from inception until October 2017. Cohort studies that reported on the predictive accuracy of PAMG‐1, fFN and phIGFBP‐1 for the prediction of sPTB within 7 days of testing in women with symptoms of preterm labor were included. Summary receiver–operating characteristics (ROC) curves and sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and positive (LR+) and negative (LR–) likelihood ratios were generated using indirect methods for the calculation of pooled effect sizes with a bivariate linear mixed model for the logit of sensitivity and specificity, with each diagnostic test as a covariate, as described by the Cochrane Handbook for Systematic Reviews of Diagnostic Test Accuracy. Results Bivariate mixed model pooled sensitivity of PAMG‐1, fFN and phIGFBP‐1 for the prediction of sPTB ≤ 7 days was 76% (95% CI, 57–89%), 58% (95% CI, 47–68%) and 93% (95% CI, 88–96%), respectively; pooled specificity was 97% (95% CI, 95–98%), 84% (95% CI, 81–87%) and 76% (95% CI, 70–80%) respectively; pooled PPV was 76.3% (95% CI, 69–84%) (P < 0.05), 34.1% (95% CI, 29–39%) and 35.2% (95% CI, 31–40%), respectively; pooled NPV was 96.6% (95% CI, 94–99%), 93.3% (95% CI, 92–95%) and 98.7% (95% CI, 98–99%), respectively; pooled LR+ was 22.51 (95% CI, 15.09–33.60) (P < 0.05), 3.63 (95% CI, 2.93–4.50) and 3.80 (95% CI, 3.11–4.66), respectively; and pooled LR– was 0.24 (95% CI, 0.12–0.48) (P < 0.05), 0.50 (95% CI, 0.39–0.64) and 0.09 (95% CI, 0.05–0.16), respectively. The areas under the ROC curves for PAMG‐1, fFN and phIGFBP‐1 for sPTB ≤ 7 days were 0.961, 0.874 and 0.801, respectively. Conclusions In the prediction of sPTB within 7 days of testing in women with signs and symptoms of PTL, the PPV of PAMG‐1 was significantly higher than that of phIGFBP‐1 or fFN. Other diagnostic accuracy measures did not differ between the three biomarker tests. As prevalence affects the predictive performance of a diagnostic test, use of a highly specific assay for a lower‐prevalence syndrome such as sPTB may optimize management

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P &lt; 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

A Comparison of the Effects of Several Foliar Forms of Magnesium Fertilization on &lsquo;Superior Seedless&rsquo; (Vitis vinifera L.) in Saline Soils

Magnesium (Mg) is the most essential element constituent in chlorophyll molecules that regulates photosynthesis processes. The physiological response of &lsquo;Superior Seedless&rsquo; grapes was evaluated under different foliar magnesium fertilization such as sulfate magnesium (MgSO4&middot;7 H2O), magnesium disodium EDTA (Mg-EDTA), and magnesium nanoparticles (Mg-NPs) during the berry development stages (flowering, fruit set, veraison, and harvest). In general, the &lsquo;Superior Seedless&rsquo; vine had a higher performance in photosynthesis with Mg-NPs application than other forms. The Fy/Fm ratio declined rapidly after the fruit set stage; then, it decreased gradually up until the harvesting stage. However, both MgSO4 and Mg-EDTA forms showed slight differences in Fv/Fm ratio during the berry development stages. The outcomes of this research suggest that the Fv/Fm ratio during the growth season of the &lsquo;Superior Seedless&rsquo; vine may be a good tool to assess magnesium fertilization effects before visible deficiency symptoms appear. Mg-NPs are more effective at improving &lsquo;Superior Seedless&rsquo; berry development than the other magnesium forms. These findings suggest that applying foliar Mg-NPs to vines grown on salinity-sandy soil alleviates the potential Mg deficiency in &lsquo;Superior Seedless&rsquo; vines and improves bunches quality

The role

Introduction: There are several reasons for endoscopic surgery failure; some of the major causes are adhesion formation and osteal stenosis. The commonest anatomic finding in revision endoscopic surgery is an obstructed or stenosed ostium. Adhesion and stenosis after surgery are usually due to scar tissue or granulation formation during the tissue recovery process. The patency and the size of the sinus ostium and limiting cicatricial fibrosis are two significant factors in the evaluation of a successful endoscopic sinus surgery. To limit the spontaneous closure rate; several methods were used to prevent re-stenosis of the sinuses ostium such as the application of mitomycin C which inhibits fibroblast formation after surgery, or placement of a stent or balloon catheter dilatation at the middle meatus. Objectives: The aim of this study is to evaluate the effect of local rotational flap insertion in maxillary and sphenoid sinus ostia in minimizing postoperative ostium stenosis. Study design: A prospective study is done on 160 patients diagnosed as having chronic maxillary and/or sphenoid sinusitis patients who are divided into two equal groups, a study and a control group. All patients in the study group will undergo rotational flap coverage of the ostia and the control group arm will undergo middle meatal antrostomy and sphenoid ostium enlargement without flaps. Results: Significant reduction in re-stenosis rate after 9 months of follow up. Conclusion: Middle meatal antrostomy and sphenoidotomy by this technique have a higher patency rate than the standard techniques after 9 months of surgery

STR-843: CARACTÉRISATION DE LA MAÇONNERIE DE PIERRES POUR L’ÉVALUATION SISMIQUE DE BÂTIMENTS PATRIMONIAUX

L’évaluation de la résistance sismique des bâtiments patrimoniaux en maçonnerie de pierres non armée (MNA) est la première étape nécessaire à l’évaluation du risque sismique associé et l\u27élaboration d\u27une stratégie de réhabilitation optimale tout en conservant les caractéristiques de l\u27architecture d\u27origine. L’évaluation de la résistance latérale des murs en MNA est complexifiée par le fait qu’ils sont souvent composés de deux ou trois parois de matériaux aux propriétés variables, et leur résistance aux charges sismiques est compromise par la dégradation des joints de mortier. Dans l\u27Est du Canada, les caractéristiques des murs porteurs des bâtiments patrimoniaux, telles que leur composition, l’agencement des composantes et leurs matériaux, sont peu connues. De plus, les propriétés mécaniques de ses murs en MNA ont fait l’objet de très peu de recherches, rendant difficile la prédiction fiable de leur résistance sismique d’autant plus que les modèles actuels de prédiction de résistance latérale des murs en MNA nécessitent les valeurs de résistances à la compression et au cisaillement spécifiques au site. Cet article présente une évaluation expérimentale des paramètres de résistance à la compression et au cisaillement d’assemblages en maçonnerie de pierre calcaire et de mortier de ciment et chaux. On détaille le plan d’expérimentation, l’analyse et la discussion des résultats incluant : la résistance à la compression des mortiers de chaux et des blocs de pierre calcaire, le comportement force-déplacement en compression d’assemblage de maçonnerie, la résistance au cisaillement de joint et la résistance à la flexion du joint