14 research outputs found
A Mathematical Approach for Predicting Sufficient Separation Gap between Adjacent Buildings to Avoid Earthquake-Induced Pounding
Studies on earthquake-related damage underscore that buildings are vulnerable to significant harm or even collapse during moderate to strong ground motions. Of particular concern is seismic-induced pounding, observed in numerous past and recent earthquakes, often resulting from inadequate separation gaps between neighboring structures. This study conducted an experimental and numerical investigation to develop a mathematical equation to calculate a sufficient separation gap in order to avoid the collision between adjacent mid-rise steel-frame buildings during seismic excitation. In this study, the coupled configuration of 15-storey & 10-storey, 15-storey & 5-storey, and 10-storey & 5-storey steel frame structures was considered in the investigation. The investigation concluded with a large number of data outputs. The outputs were used to predict structural behavior during earthquakes. The obtained data were categorized into three main categories according to the earthquake's Peak Ground Acceleration (PGA) levels. Also, the derived equations were divided into three different equations to estimate the required seismic gap between neighboring buildings accordingly. The derived equations are distilled to empower engineers to rigorously evaluate non-irregular mid-rise steel frame buildings. Doi: 10.28991/CEJ-2023-09-10-02 Full Text: PD
Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial
SummaryBackground Azithromycin has been proposed as a treatment for COVID-19 on the basis of its immunomodulatoryactions. We aimed to evaluate the safety and efficacy of azithromycin in patients admitted to hospital with COVID-19.Methods In this randomised, controlled, open-label, adaptive platform trial (Randomised Evaluation of COVID-19Therapy [RECOVERY]), several possible treatments were compared with usual care in patients admitted to hospitalwith COVID-19 in the UK. The trial is underway at 176 hospitals in the UK. Eligible and consenting patients wererandomly allocated to either usual standard of care alone or usual standard of care plus azithromycin 500 mg once perday by mouth or intravenously for 10 days or until discharge (or allocation to one of the other RECOVERY treatmentgroups). Patients were assigned via web-based simple (unstratified) randomisation with allocation concealment andwere twice as likely to be randomly assigned to usual care than to any of the active treatment groups. Participants andlocal study staff were not masked to the allocated treatment, but all others involved in the trial were masked to theoutcome data during the trial. The primary outcome was 28-day all-cause mortality, assessed in the intention-to-treatpopulation. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936.Findings Between April 7 and Nov 27, 2020, of 16 442 patients enrolled in the RECOVERY trial, 9433 (57%) wereeligible and 7763 were included in the assessment of azithromycin. The mean age of these study participants was65·3 years (SD 15·7) and approximately a third were women (2944 [38%] of 7763). 2582 patients were randomlyallocated to receive azithromycin and 5181 patients were randomly allocated to usual care alone. Overall,561 (22%) patients allocated to azithromycin and 1162 (22%) patients allocated to usual care died within 28 days(rate ratio 0·97, 95% CI 0·87–1·07; p=0·50). No significant difference was seen in duration of hospital stay (median10 days [IQR 5 to >28] vs 11 days [5 to >28]) or the proportion of patients discharged from hospital alive within 28 days(rate ratio 1·04, 95% CI 0·98–1·10; p=0·19). Among those not on invasive mechanical ventilation at baseline, nosignificant difference was seen in the proportion meeting the composite endpoint of invasive mechanical ventilationor death (risk ratio 0·95, 95% CI 0·87–1·03; p=0·24).Interpretation In patients admitted to hospital with COVID-19, azithromycin did not improve survival or otherprespecified clinical outcomes. Azithromycin use in patients admitted to hospital with COVID-19 should be restrictedto patients in whom there is a clear antimicrobial indication
Improving the Mechanical Properties of Concrete Mixtures by Shape Memory Alloy Fibers and Silica Fume
Concrete, as one of the most widely applied materials in buildings, has high environmental impacts. Researchers are continually seeking solutions to mitigate these environmental issues while enhancing the mechanical strength and durability of concrete. However, there is a lack of studies on the effect of combining silica fume (SF) as pozzolanic materials and shape memory alloy (SMA) fibers on the mechanical properties of concrete. Moreover, there is very limited research on the influence of these materials on concrete mixtures after primary failure cracks using the secondary compressive strength test. In this research, 0.1, 0.2, and 0.3% SMA and 5, 7.5, and 10% SF were applied and then subjected to compressive strength, splitting tensile strength, flexural strength, secondary compressive strength, and ultrasonic pulse velocity tests. According to the results, 10% SF is more economical, which increases the compressive, splitting tensile, and flexural strength by 14%, 7%, and 10%, respectively. Also, using 0.3% SMA improves the compressive, splitting tensile, and flexural strength by 2%, 5%, and 8%, respectively. Furthermore, SMA has the ability to reduce the secondary compressive strength compared to other samples, indicating the quality of this material in controlling stress after cracking. Finally, it was indicated that the combined use of these two materials increases the strength parameters
Permisividad, control y afecto parental y consumo de drogas en adolescentes
Background: Parents play an important role in determining the risk of children's drug use. The aim of this study was to analyse how certain family-related variables (permissiveness toward drug use, and parental control and affect) were linked to the use of alcohol, tobacco and cannabis, based on young people's self-report of such variables. Method: The sample was composed of 1,428 school children (51.8% males) aged between 11 and 19 from Mallorca (Spain). Results: We found that the young people who perceived their parents as permissive and those who perceived less maternal control and higher levels of both paternal and maternal affect were more likely to use alcohol, tobacco and cannabis. Sex differences were found within this pattern. Variables of maternal affect and control were not influential among males, whereas the general pattern was maintained among females. Conclusions: This study highlights the importance of perceived permissiveness and the need of considering parent's and children's gender when providing control and affect, as fathers will influence male children whereas mothers will influence female childrenAntecedentes: los padres juegan un papel importante a la hora de determinar el riesgo del consumo de drogas de sus hijos. El objetivo de este estudio fue analizar cómo la permisividad hacia el consumo de drogas y control y afecto del padre y madre estaban relacionadas con el consumo de alcohol, tabaco y cannabis. Método: la muestra estuvo compuesta por 1.428 jóvenes (51,8% varones) de entre 11 y 19 años de Mallorca. Resultados: aquellos jóvenes que percibían a sus padres más permisivos, con menor control por parte de la madre y mayores niveles de afecto tanto materno como paterno, tenían más probabilidades de consumir alcohol, tabaco y cannabis. Se encontraron diferencias en función del sexo dentro de este patrón. Las variables de afecto y control por parte de la madre no fueron influyentes en el caso de los varones, mientras que el patrón general se mantuvo en el caso de las mujeres. Conclusiones: este estudio resalta la importancia de la permisividad percibida y es necesario tener en cuenta el sexo de padres e hijos a la hora de proporcionar afecto y control, ya que son los padres los que influyen en los hijos varones y las madres en las mujeresS
Simulation and modeling of polymer concrete panels using deep neural networks
The most often utilized construction material worldwide is concrete. Extensive experiments are carried out each year to study the physical, mechanical, and chemical properties of concrete, which are costly and time-consuming. This study focuses on avoiding redundant tests by applying the machine learning (ML) method to predict temperature-dependent polymer concrete qualities. In this work, as a strong tool of the ML method, a deep neural network (DNN) is used to examine the five temperature-dependent mechanical characteristics of concrete, including Poisson's ratio, Young's modulus, specific heat, coefficient of thermal expansion, and thermal conductivity. A 5-fold cross-validation method was used to verify the strategy in this research and get rid of split bias in testing and training. This study demonstrates the material properties of temperature-dependent polymer concrete followed by mathematical modeling of a steel-polymer concrete panel used for various civil applications. Temperature-dependent equations are determined using constitutive heat transfer and Cartesian coordinates. In addition, a thermal shock load acts on the upper part, and the lower part becomes an isothermal state with no heat flow. In order to account for the limited speed at which temperature waves travel, two distinct theories of generalized thermoelasticity are employed: the Lord-Shulman (LS) and the Green-Lindsay (GL) theories. The Fast Laplace Inverse Transform Method (FLITM) is used to transfer the results from the Laplace domain to the time domain. In addition, a three-dimensional differential quadrature approach (3D-DQA) using three Chebyshev-Gaussian-Robat functions for solving temperature-dependent equations is presented. In conclusion, some suggestions for improving the stability of polymer concrete panels are detailed and will be compiled in a future manual
Psicothema
Resumen tomado de la publicaciónAntecedentes: los padres juegan un papel importante a la hora de determinar el riesgo del consumo de drogas de sus hijos. El objetivo de este estudio fue analizar cómo la permisividad hacia el consumo de drogas y control y afecto del padre y madre estaban relacionadas con el consumo de alcohol, tabaco y cannabis. Método: la muestra estuvo compuesta por 1.428 jóvenes (51,8% varones) de entre 11 y 19 años de Mallorca. Resultados: aquellos jóvenes que percibían a sus padres más permisivos, con menor control por parte de la madre y mayores niveles de afecto tanto materno como paterno, tenían más probabilidades de consumir alcohol, tabaco y cannabis. Se encontraron diferencias en función del sexo dentro de este patrón. Las variables de afecto y control por parte de la madre no fueron influyentes en el caso de los varones, mientras que el patrón general se mantuvo en el caso de las mujeres. Conclusiones: este estudio resalta la importancia de la permisividad percibida y es necesario tener en cuenta el sexo de padres e hijos a la hora de proporcionar afecto y control, ya que son los padres los que influyen en los hijos varones y las madres en las mujeres.Universidad de Oviedo. Biblioteca de Psicología; Plaza Feijoo, s/n.; 33003 Oviedo; Tel. +34985104146; Fax +34985104126; [email protected]