Punching Shear Strength Prediction for Reinforced Concrete Flat Slabs without Shear Reinforcement

Failure of flat slabs usually occurs by punching shear mode. Current structural codes provide an experience-based design provision for punching shear strength which is often associated with high bias and variance. This paper investigates the effect of adding a horizontal reinforcement mesh at the top of the slab-column connection zone on punching the shear strength of flat slabs. A new equation considering the effect of adding this mesh was proposed to determine the punching shear strength. The proposed equation is based on the Critical Shear Crack Theory combined with the analysis of results extracted from previous experimental and theoretical studies. Moreover, the equation of load-rotation curves for different steel ratios together with the failure criterion curves were evaluated to get the design points. The investigated parameters were the slab thicknesses and dimensions, concrete strengths, size of the supporting column, and steel ratios. The model was validated using a new set of specimens and the results were also compared with the predictions of different international design codes (ACI318, BS8110, AS3600, and Eurocode 2). Statistical analysis provides that the proposed equation can predict the punching shear strength with a level of high accuracy (Mean Square Error =2.5%, Standard Deviation =0.104, Mean=1.0) and over a wide range of reinforcement ratios and compressive strengths of concrete. Most of the predictions were conservative with an underestimation rate of 12%. Doi: 10.28991/CEJ-2022-08-01-013 Full Text: PD

The Psychometric Properties of the Arabic Preschool Activity Card Sort

Background. The Preschool Activity Card Sort (PACS) is an interview-based assessment tool to measure participation of preschool children with age range from 3 to 6 years. Objective of Study. The purpose of this study was to establish the psychometric properties of the recently translated Arabic PACS (A-PACS). Methods. One hundred fifty-one Jordanian parents participated in the study representing different geographical areas. Children were almost equally distributed between males and females and into three age groups. Construct and concurrent validity were examined as well as the internal consistency of the scale and the test-retest reliability. Findings. The A-PACS was able to differentiate between the participation level of young and old children in the domains of education, community mobility, and low demand leisure of the A-PACS giving evidence to its construct validity and it significantly correlated with some aspects of the Vineland Adaptive Behavior Scale (VABS) giving evidence to its concurrent validity. The A-PACS showed excellent overall internal consistency (α=.859) for all domains and good test-retest reliability (r=.976, p<.001). Conclusion. The A-PACS can be considered as a valid and reliable tool to measure participation of preschool children with normal development from Arabic cultures. Future studies should focus on the validity of the A-PACS for use with children with disabilities

Systematic Literature Review

Abstract This study was conducted to assess the risk of cancer associated with air pollution in Eastern Mediterranean Region (EMR) by summarizing the existing knowledge from previous studies in the region and to identify knowledge and research gaps to support further research efforts. Combinations of search terms from three categories (&quot;country&quot; keywords AND &apos;air pollution&quot; keywords AND &quot;cancer&quot; keywords) were used to search for the relevant literature published between January 2000 and June 2016 using MEDLINE and other databases. Six case-control studies and three studies of other designs had assessed the association between air pollution and cancer in the EMR and met the inclusion criteria. These studies have assessed the effect of various indoor and outdoor air pollutants on the risk of different types of cancer. In this review, cancers were classified into: lung cancer; nasopharyngeal cancer; urinary bladder cancer; overall incidence of cancer in adults; and childhood cancer incidence. Limited epidemiological studies were found in the literature that properly address cancer incidence and air pollution in the EMR countries. Outdoor air pollution was not properly addressed in the included studies. Studies showed that using fuel for heating and living near an electricity generator and diesel exhaust exposure were significant contributors to lung cancer. NO 2 has been shown to increase the risk of lung and breast cancer incidence. PAHs exposure did not increase the risk of cancer incidence. In conclusion, studies on the link between air pollution and cancer in EMR are limited to few studies in few countries. The reviewed studies have many limitations that make the evidence about the link between air pollution and cancer weak

Implications of texture 4 zero lepton mass matrices for U_{e3}

Lepton mass matrices similar to texture 4 zero quark mass matrices, known to be quite successful in explaining the CKM phenomenology, have been considered for finding the mixing matrix element U_{e3} (\equiv s_{13}) respecting the CHOOZ constraint, with s_{12} and \Delta m_{12}^2 constrained by SNP and s_{23} and \Delta m_{23}^2 constrained by ANP. Taking charged lepton mass matrix M_l to be diagonal, we find that the ranges of s_{13} corresponding to different SNP solutions very well include the corresponding values of s_{13} found by Akhmedov et al. by considering neutrino mass matrix M_{\nu} with no texture zeros. Considering M_l and M_{\nu} both to be real and non-diagonal, s_{13} ranges for the four SNP solutions come out to be: \sim 0-0.19 (LMA), 0.038-0.093 (SMA), 0.042-0.095 (LOW), 0.038-0.096 (VO) which remain of the same order when M_l and M_{\nu} are considered to be complex and non-diagonal.Comment: 13 pages, LaTe

Collider aspects of flavour physics at high Q

This review presents flavour related issues in the production and decays of heavy states at LHC, both from the experimental side and from the theoretical side. We review top quark physics and discuss flavour aspects of several extensions of the Standard Model, such as supersymmetry, little Higgs model or models with extra dimensions. This includes discovery aspects as well as measurement of several properties of these heavy states. We also present public available computational tools related to this topic.Comment: Report of Working Group 1 of the CERN Workshop ``Flavour in the era of the LHC'', Geneva, Switzerland, November 2005 -- March 200

Improved Dynamic Voltage Regulation in a Droop Controlled DC Nanogrid Employing Independently Controlled Battery and Supercapacitor Units

DC bus voltage signaling (DBS) and droop control are frequently employed in DC nano and microgrids with distributed energy resources (DERs) operating in a decentralized way. This approach is effective in enforcing the desired contributions of power sources and energy storage systems (ESSs) in steady-state conditions. The use of supercapacitors (SCs) along with batteries in a hybrid energy storage system (HESS) can mitigate the impact of high and fast current variations on the losses and lifetime of the battery units. However, by controlling the HESS as a single unit, one forfeits the potential contribution of the SC and its high power capabilities to dynamically improve voltage regulation in a DC nanogrid. This paper discusses an approach where the SC interface is controlled independently from the battery interface, with a small droop factor and a high pass filter (HPF), to produce high and short current pulses and smooth DC bus voltage variations due to sudden power imbalances in the DC nanogrid. Experimental results are presented to show that, unlike in a conventional HESS, the SC unit can be used to improve the dynamic voltage regulation of the DC nanogrid and, indirectly, mitigate the high and fast current variations in the battery

A Novel PV Maximum Power Point Tracking Based on Solar Irradiance and Circuit Parameters Estimation

This research paper presents a novel maximum power point taking (MPPT) algorithm. The algorithm uses an adaptive calculation block to estimate the solar irradiance and the PV I&ndash;V curve circuit parameters based on the PV panel&rsquo;s measured output current and voltage. In the proposed algorithm, the output power does not oscillate around the maximum power point (MPP) compared to conventional MPPT methods. Moreover, the proposed algorithm does not require expensive solar irradiance sensors compared with trackers that depend on measured solar irradiance. In addition, the proposed MPPT can handle the fast variation in solar irradiance. The PV panel nonlinear I&ndash;V curve was modeled using a single-diode PV. The algorithm with the adaptive block was tested separately to verify the ability of the system to estimate the solar irradiance and the circuit parameters. The solar system was then simulated using MATLAB/Simulink to evaluate the robustness of the proposed method under steady-state and during sudden changes in solar irradiance and load. The proposed solar system reaches the steady-state in 8 ms after a step-change in the solar irradiance. In the worst-case scenario, the proposed system achieves a relative error of around 2.64% in estimating the solar irradiance at 600 W/m2 with an efficiency of 99.3%

Improved Dynamic Voltage Regulation in a Droop Controlled DC Nanogrid Employing Independently Controlled Battery and Supercapacitor Units

DC bus voltage signaling (DBS) and droop control are frequently employed in DC nano and microgrids with distributed energy resources (DERs) operating in a decentralized way. This approach is effective in enforcing the desired contributions of power sources and energy storage systems (ESSs) in steady-state conditions. The use of supercapacitors (SCs) along with batteries in a hybrid energy storage system (HESS) can mitigate the impact of high and fast current variations on the losses and lifetime of the battery units. However, by controlling the HESS as a single unit, one forfeits the potential contribution of the SC and its high power capabilities to dynamically improve voltage regulation in a DC nanogrid. This paper discusses an approach where the SC interface is controlled independently from the battery interface, with a small droop factor and a high pass filter (HPF), to produce high and short current pulses and smooth DC bus voltage variations due to sudden power imbalances in the DC nanogrid. Experimental results are presented to show that, unlike in a conventional HESS, the SC unit can be used to improve the dynamic voltage regulation of the DC nanogrid and, indirectly, mitigate the high and fast current variations in the battery

Renewable Energy Role in Climate Stabilization and Water Consumption Minimization in Jordan

Climate change is one of the most essential phenomena studied by several researchers in the last few decades. The main reason this phenomenon occurs is greenhouse gases (GHG), chiefly CO2 emissions. About 30% of the created GHG emissions are achieved by electricity generation. This article investigates the role of renewable energy projects in Jordan, specifically wind and solar energy, in mitigating climate change and water consumption reduction using RETScreen software. It was found that the cumulative water consumption reduction from 2017 to 2021 due to the use of wind and solar projects is equal to 6.9491 × 109 gallons. Finally, the results show that the future dependence on renewable energy projects in Jordan to meet the growth in demand by the year 2030 reduces the expected increment in the climate temperature by 1.047 °C by that year