Shear Behavior of High-Performance Reinforced Concrete Beams

High-performance concrete (HPC) is one of such new material that has a major improvement over conventional concrete; however, its behavior has to be fully understood. This paper presents experimental and numerical investigations in order to study the shear behavior of high-performance reinforced concrete beams. Four RC-HPC beams were tested experimentally in order to study the effect of the existence of web reinforcement and bar diameter of the web reinforcement as well as the amount of the tensile longitudinal steel bars on the shear behavior. Test results showed higher values of shear strength, stiffness, ductility and controlled the concrete cracking behavior due to the presence of stirrups. The ultimate load for beam having shear reinforcement of 6 mm diameter increased by about 16% compared to that of control beam BI-1 without shear reinforcement, while, that increase reached up to 34% for beam having 8 mm diameter web reinforcement. Besides, the numerical modeling enabled to capture satisfactory the behavior of HPC beam so that it can be used to study the effect of more parameters on the behavior of HPC beams

Shear Behavior of High-Performance Reinforced Concrete Beams

High-performance concrete (HPC) is one of such new material that has a major improvement over conventional concrete; however, its behavior has to be fully understood. This paper presents experimental and numerical investigations in order to study the shear behavior of high-performance reinforced concrete beams. Four RC-HPC beams were tested experimentally in order to study the effect of the existence of web reinforcement and bar diameter of the web reinforcement as well as the amount of the tensile longitudinal steel bars on the shear behavior. Test results showed higher values of shear strength, stiffness, ductility and controlled the concrete cracking behavior due to the presence of stirrups. The ultimate load for beam having shear reinforcement of 6 mm diameter increased by about 16% compared to that of control beam BI-1 without shear reinforcement, while, that increase reached up to 34% for beam having 8 mm diameter web reinforcement. Besides, the numerical modeling enabled to capture satisfactory the behavior of HPC beam so that it can be used to study the effect of more parameters on the behavior of HPC beams

DEMO: Venom: a Visual and Experimental Bluetooth Low Energy Tracking System

International audienceThe Bluetooth Low Energy (BLE) protocol is being included in mobile devices such as smartphones, headphones and smartwatches. As part of the BLE service discovery mechanism, devices announce their presences by broadcasting radio signals called advertisement packets that can be collected with off-the-shelf hardware and software. To avoid the risk of tracking based on those messages, BLE features an address randomization mechanism substituting the device MAC address with random temporary pseudonyms. However, the payload of advertisement packets still contains fields that can negate the randomization mechanism by exposing static identifiers. In this paper, we present Venom (Visual and ExperimeNtal BluetOoth Low Energy tracking systeM), an experimental tracking platform aiming to raise public awareness about physical tracking technologies and experiment privacy-preserving mechanisms. Venom tracks users by collecting advertisement packets broadcasted by their BLE-enabled devices, and displays related information

Synthesis, X-ray, Hirshfeld, and AIM Studies on Zn(II) and Cd(II) Complexes with Pyridine Ligands

The synthesis and crystal structures of three heteroleptic complexes of Zn(II) and Cd(II) with pyridine ligands (ethyl nicotinate (EtNic), N,N-diethylnicotinamide (DiEtNA), and 2-amino-5-picoline (2Ampic) are presented. The complex [Zn(EtNic)2Cl2] (1) showed a distorted tetrahedral coordination geometry with two EtNic ligand units and two chloride ions as monodentate ligands. Complexes [Zn(DiEtNA)(H2O)4(SO4)]·H2O (2) and [Cd(OAc)2(2Ampic)2] (3) had hexa-coordinated Zn(II) and Cd(II) centers. In the former, the Zn(II) was coordinated with three different monodentate ligands, which were DiEtNA, H2O, and SO42−. In 3, the Cd(II) ion was coordinated with two bidentate acetate ions and two monodentate 2Ampic ligand units. The supramolecular structures of the three complexes were elucidated using Hirshfeld analysis. In 1, the most important interactions that governed the molecular packing were O···H (15.5–15.6%), Cl···H (13.6–13.8%), Cl···C (6.3%), and C···H (10.3–10.6%) contacts. For complexes 2 and 3, the H···H, O···H, and C···H contacts dominated. Their percentages were 50.2%, 41.2%, and 7.1%, respectively, for 2 and 57.1%, 19.6%, and 15.2%, respectively, for 3. Only in complex 3, weak π-π stacking interactions between the stacked pyridines were found. The Zn(II) natural charges were calculated using the DFT method to be 0.8775, 1.0559, and 1.2193 for complexes 1–3, respectively. A predominant closed-shell character for the Zn–Cl, Zn–N, Zn–O, Cd–O, and Cd–N bonds was also concluded from an atoms in molecules (AIM) study

Fabrication and Characterization of Effective Biochar Biosorbent Derived from Agricultural Waste to Remove Cationic Dyes from Wastewater

The main aim of this work is to treat sugarcane bagasse agricultural waste and prepare an efficient, promising, and eco-friendly adsorbent material. Biochar is an example of such a material, and it is an extremely versatile and eco-friendly biosorbent to treat wastewater. Crystal violet (CV)-dye and methylene blue (MB)-dye species are examples of serious organic pollutants. Herein, biochar was prepared firstly from sugarcane bagasse (SCB), and then a biochar biosorbent was synthesized through pyrolysis and surface activation with NaOH. SEM, TEM, FTIR, Raman, surface area, XRD, and EDX were used to characterize the investigated materials. The reuse of such waste materials is considered eco-friendly in nature. After that, the adsorption of MB and CV-species from synthetically prepared wastewater using treated biochar was investigated under various conditions. To demonstrate the study’s effectiveness, it was attempted to achieve optimum effectiveness at an optimum level by working with time, adsorbent dose, dye concentration, NaCl, pH, and temperature. The number of adsorbed dyes reduced as the dye concentrations increased and marginally decreased with NaCl but increased with the adsorbent dosage, pH, and temperature of the solution increased. Furthermore, it climbed for around 15 min before reaching equilibrium, indicating that all pores were almost full. Under the optimum condition, the removal perecentages of both MB and CV-dyes were ≥98%. The obtained equilibrium data was represented by Langmuir and Freundlich isotherm models. Additionally, the thermodynamic parameters were examined at various temperatures. The results illustrated that the Langmuir isotherm was utilized to explain the experimental adsorption processes with maximum adsorption capacities of MB and CV-dyes were 114.42 and 99.50 mgg$_{−1}$, respectively. The kinetic data were estimated by pseudo-first and pseudo-second-order equations. The best correlation coefficients of the investigated adsorption processes were described by the pseudo-second-order kinetic model. Finally, the data obtained were compared with some works published during the last four years

Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey

Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020

Une aquaculture intelligente et durable : application à la ferme d'aquaculture de NOVATON AG

Cette thèse présente la conception et la construction d'une ferme piscicole intelligente et durable. La ferme est basée sur le concept d'aquaculture hybride qui combine les avantages du système d'aquaculture à recirculation (RAS), le rejet sans eau (ZWD) et la technologie intelligente. Le système utilise les dernières technologies, y compris la surveillance et l'automatisation, garantissant un rejet d'eau nul, une bonne qualité de l'eau, une consommation d'énergie réduite et une biosécurité élevée. Il n'utilise pas de produits chimiques dans le processus d'aquaculture. La thèse décrit la conception de ce système, y compris le système hydraulique, le système de surveillance intelligent, le régime d'alimentation et le contrôle des paramètres biologiques. Des tests en Arabie saoudite, en Indonésie et à Zurich ont montré des performances élevées de ce système avec un taux de survie d'environ 90 %. Les observations ont montré la capacité du système à maintenir la qualité de l'eau dans les gammes optimales de qualité de l'eau, à réduire la consommation d'énergie et à maintenir un recyclage efficace des déchets de crevettes, orientant l'adaptation du système dans différents modèles de fermes piscicoles terrestres et offshore.Les contributions de l'auteur dans le domaine de l'aquaculture se concentrent principalement sur la construction d'une nouvelle génération de fermes durables. Avec un rejet d'eau proche de zéro, capable de recycler les eaux effluentes du cycle d'élevage précédent pour être réutilisées dans le cycle d'élevage suivant. L'auteur a également contribué au domaine en intégrant l'énergie renouvelable dans l'équation de l'énergie consommée par la ferme, abaissant drastiquement l'énergie requise dans le processus d'élevage énergivore. Cette approche nouvelle et simpliste de l'aquaculture peut également être adaptée par les dirigeants et les entreprises aquacoles du monde entier. L'infrastructure et les conceptions présentées dans cette thèse peuvent être mises en œuvre partout dans le monde.La contribution de ce travail dans le domaine de l'aquaculture z un impact socio-économique sur les pêcheurs traditionnels, les transformant, de pêcheurs/plongeurs en exploitants agricoles, augmentant leur niveau de vie et diminuant les risques élevés d'être en haute mer.This thesis presents the design and construction of a smart and sustainable fish farm. The farm is based on the hybrid aquaculture concept that combines the advantages of the recirculation aquaculture system (RAS), the zero-water discharge (ZWD), and intelligent technology. The system's smartness uses the latest technology, including monitoring and automation, ensuring zero water discharge, good water quality, reduced energy consumption, and high biosecurity. In addition, the system does not use chemicals in the aquaculture process. The thesis describes the design of this system, including the hydraulic system, the intelligent monitoring system, the feeding regime, and the control of the biological parameters. Tests were conducted in KSA, Indonesia, and Zurich showed high performance of this system with around 90% survival rate. In addition, observations showed the system's capacity to maintain the water quality parameters within the optimal water quality ranges, reduce energy consumption, and sustain efficient shrimp waste recycling, directing the system's adaptation in different models of fish land-based and offshore farms.The author’s contributions to the field of aquaculture mainly focus on the building of a new generation of sustainable farms. With close to zero water discharge, capable of recycling effluent waters from the previous rearing cycle to be reused in the next rearing cycle. The author has also contributed to the field by incorporating renewable energy into the equation of energy consumed by the farm, drastically lowering the energy required in the energy intensive rearing process. This new and simplistic approach to aquaculture may also be adapted by aquaculture leaders and business around the world. The infrastructure and designs presented in this thesis may be implemented all around the globe.Furthermore, the authors contributions to the field of aquaculture have socio-economic impact on traditional fishers, transforming them, from fishers/divers to farm operators, increasing their standards of living and decreasing the high risks of being in the open seas

Kinetics of the reaction between methyl 2,4-dichloro-3,5-dinitrobenzoate and piperidine — Solvent effect

1348-1354The rate constant for the reaction of methyl 2,4-dichloro-3,5-dinitrobenzoate (1) with different piperidine concentrations have been measured spectrophotometrically in nine pure solvents, viz. methanol, ethanol, n-propanol, isopropanol, t-butyl alcohol, acetonitrile, dimethysulphoxide, dioxane and benzene at different temperatures to study the effect of the solvents. The kinetic results postulate three solvation models: (a) alkanol extensively solvating the amine and weakening the intramolecular hydrogen bonding in the intermediate; (b) the non-polar solvents enhance the intramolecular hydrogen bonding in the intermediate increasing the nucleophilicity of amine; (c) the dipolar aprotic solvents solvate the amine and timely solvating the intermediate by intermolecular hydrogen bond. The solvent parameters have been correlated with the rate constant for the reaction through linear free energy relationships. The adequacy of the multi-parametric scales as appropriate approaches to describe the solvent features in microscopic environments has also been analyzed

Smart and Sustainable Aquaculture Farms

International audienceThis paper presents the design and construction of a smart and sustainable fish farm. The farm is based on the hybrid aquaculture concept that combines the advantages of the recirculation aquaculture system (RAS), the zero-water discharge (ZWD), and smart technology. The system’s smartness consists of using the latest technology, including monitoring and automation, ensuring zero water discharge, good water quality, reduced energy consumption, and high biosecurity. In addition, the system does not use chemicals in the aquaculture process. The paper describes the design of this system, including the hydraulic system, the smart monitoring system, the feeding regime, and the control of the biological parameters. Tests conducted in Tabuk, Saudi Arabia, showed high performance of this system with around 90% survival rate. In addition, observations showed the system’s capacity to maintain the water quality parameters within the optimal water quality ranges, reduce energy consumption, and sustain efficient shrimp waste recycling

Case study of chemical and enzymatic degumming processes in soybean oil production at an industrial plant

Abstract The vegetable oil degumming process plays a critical role in refining edible oil. Phospholipids (PL) removal from crude extracted soybean oil (SBO) by the enzymatic degumming process has been investigated in this work. Enzymatic degumming of extracted SBO with microbial phospholipase A1 PLA-1 Quara LowP and Lecitase Ultra enzymes have also been studied comparatively. The main novelty of our work is the use of the enzymatic degumming process on an industrial scale (600 tons a day). Many parameters have been discussed to understand in detail the factors affecting oil losses during the degumming process. The factors such as chemical conditioning (CC) by phosphoric acid 85%, the enzyme dosage mg/kg (feedstock dependent), the enzymatic degumming reaction time, and the characteristics of the plant-processed SBO have been discussed in detail. As a main point, the degummed oil with a phosphorus content of < 10 mg/kg increases yield. Quara LowP and Lecitase Ultra enzymes are not specific for certain phospholipids PL; however, the conversion rate depends on the SBO phospholipid composition. After 4 h, over 99% of Phospholipids were degraded to their lysophospholipid LPL (lysolecithin). The results showed a significant effect of operating parameters and characteristics of different origins of SBO, fatty acids FFA content, Phosphorus content and total divalent metals (Calcium Ca, Magnesium Mg and Iron Fe mg/kg) content on the oil loss. The benefit of using enzymatic degumming of vegetable oils rather than traditional chemical refining is that the enzymatic degumming process reduces total oil loss. This decrease is known as enzymatic yield. The enzymatic degumming also decreases wastewater and used chemicals and running costs; moreover, it enables physical refining by lowering the residue phosphorus to < 10 mg/kg