Foliar application of chitosan zinc oxide nanoparticles on wheat productivity and water use efficiency under deficit irrigation water

The effectiveness of chitosan zinc oxide nanoparticles (CS-ZnO-NPs) on growth and yield of wheat (Triticum aestivum L., Sakha-93), zinc content and water use efficiency (WUE) under water stress were investigated. A pot experiment was conducted in a completely randomized design by foliar application of CS-ZnO-NPs. Wheat plants were sprayed four times at 15, 30, 45 and 60 days after sowing. The treatments were: control (treated with distilled water), 50, 100 and 150 ppm of CS-ZnO-NPs under 100, 80 and 60% of field capacity. Water shortage has a negative effect on growth parameters and productivity of wheat plants. While the foliar application of 150 ppm CS-ZnO-NPs significantly increased (P≤0.05) NPK content, growth parameters which in turn led to increase the productivity. The highest values of wheat yield were: 4990.55, 4453.50 and 4350.50 kg/ha under 100 80 and 60% of irrigation water, respectively at 150 ppm CS-ZnO-NPs. The highest values of N, P and K content in wheat grain were 1.95, 0.43 and 1.66, respectively at 100% FC under150 ppm CS-ZnO-NPs compared to control. Zn content in wheat grain significantly increased (P≤0.05) by application of CS-ZnO NPs. The interaction of supplementary irrigation water and CS-ZnO-NPs treatments gave clear variation in water use efficiency. The highest relative increase of WUE (23.03%) was at the highest rate of CS-ZnO-NPs (150 ppm). Overall, the data suggested that the foliar application of CS-ZnO-NPs can be an efficient strategy for improving wheat yield, water use efficiency under deficit water and one of the solutions for Zn deficiency in wheat grains

Preparation of Some Eco-friendly Corrosion Inhibitors Having Antibacterial Activity from Sea Food Waste

Chitosan is one of the important biopolymers and it is extracted from exoskeletons of crustaceans in sea food waste. It is a suitable eco-friendly carbon steel corrosion inhibitor in acid media; the deacetylation degree of prepared chitosan is more than 85.16 %, and the molecular weight average is 109 kDa. Chitosan was modified to 2-N,N-diethylbenzene ammonium chloride N-oxoethyl chitosan (compound I), and 12-ammonium chloride N-oxododecan chitosan (compound II) as soluble water derivatives. The corrosion inhibition efficiency for carbon steel of compound (I) in 1 M HCl at varying temperature is higher than for chitosan and compound (II). However, the antibacterial activity of chitosan for Enterococcus faecalis, Escherichia coli, Staphylococcus aureus, and Candida albicans is higher than for its derivatives, and the minimum inhibition concentration and minimum bacterial concentration of chitosan and its derivatives were carried out with the same strain

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

The synergistic effect of biochar and poly(2-ethyl-2-oxazoline)/poly(2-hydroxyethylmethacarylate)/chitosan) hydrogels on saline soil properties and carrot productivity

Abstract Background Soil salinity is one of the most important factors limiting crop production. Furthermore, with the increasing population and saline soil worldwide there is no choice but to utilize saline soil to increase the agricultural regions. Therefore, to improve carrot productivity under saline conditions, it is necessary to provide good management such as applying hydrogels and biochar for improving soil properties. Methodology Hydrogels (PEtOx-HEMA-CS) were synthesized from poly (2-ethyl-2-oxazoline), 2-hydroxyethyl methacrylate (HEMA as crosslinker) and chitosan (CS) via exposure those to gamma irradiation dose; 30 kGy of dose rate 0.9 kGy/h and obtained three types of hydrogels according to concentration of chitosan used. The PEtOx-HEMA-CS hydrogels were enhanced water holding capacity for agriculture purposes. The chemical structures of obtained hydrogels were characterized by FTIR, XRD and SEM. The swelling (%) and gelation (%) were determined. Biochar (BC) as an active substance was physically mixed with those hydrogels at various ratios (0/100, 0.5/99.5, 1/99 and 100/0 (g/g) biochar/hydrogels). BC, PEtOx-HEMA-CS and the mixture of PEtOx-HEMA-CS-BC were mixed with saline soil at ratio 0.05% and 0.1% w/w of obtained materials/soil. A pot experiment was conducted to mitigate the salinity hazards on carrot productivity using biochar with and without hydrogels. Mean maximum temperature, minimum temperature, precipitation, relative humidity and wind speed from September to December in the studied region are 28.66 ℃, 15.76 ℃, 0.01 mm, 58.81%, 5.94 km/h, respectively. Findings The obtained data referred that there is a significant decrease in soil salinity and exchangeable sodium percentage and increase in organic matter, cation exchange capacity, field capacity, permanent wilting point and available water especially at (PEtOx-HEMA-CS5)0.1-BC1. The highest increment percentage of nitrogen, phosphorous and potassium were 36.36%, 70% and 72%, respectively. In addition, the relative increase of carrot productivity was 49.63% at the highest rates of biochar and hydrogels. However, the highest value of water use efficiency was observed at the mixture of biochar and hydrogels at (PEtOx-HEMA-CS5)0.1-BC1. Conclusions Finally, applying biochar combined with (PEtOx-HEMA-CS5) could be recommended as a good approach to improve carrot productivity and water use efficiency under saline soil conditions. Graphical Abstrac

Etalonnage dynamique des capteurs de temperature en milieu liquide

SIGLECNRS TD Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Preparation of chitosan from the shrimp shells and its application for pre-concentration of uranium after cross-linking with epichlorohydrin

Chitosan (CTS) was first prepared by proper treatment of shrimp shells and the cross-linked chitosan (CCTS) was then synthesized by its reaction with epichlorohydrin (ECH) under alkaline conditions. Adsorption of uranium from aqueous nitrate solution onto CCTS was investigated batch wise. The adsorption isotherm and the adsorption kinetic as well as thermodynamic studies of this adsorption are carried out. The influence factors on uranium (VI) adsorption were optimized and were found to include an initial pH of 3 and a contact time of 120 min. The Langmuir adsorption model was then applied for the mathematical description of the obtained adsorption equilibrium and where its data greatly agree with that model and where the maximum adsorption capacity was estimated to be 903 mg/g. Adsorption kinetics data were also tested using pseudo-first-order and pseudo-second-order models and where the studied adsorption followed the latter. In addition, determination of the thermodynamic parameters (ΔG°, ΔH° and ΔS°) using van’t Hoff equation has indicated that the prepared CCTS can conveniently be used for uranium adsorption from its aqueous solution

Effect of Elevated Temperature on Rhyolitic Rocks’ Properties

The effect of high temperatures on rock’s thermophysical and mechanical properties is critical to the design of underground geotechnical applications. The current work investigates the impact of temperature on rhyolitic turf rock’s physical and mechanical properties. Intact cylindrical core rock samples were heated to different temperatures (200, 400, 600, and 800 °C). The uniaxial compressive strength (UCS) and elastic modulus of unheated and heated samples were determined as important mechanical properties. In addition, the effect of temperature on the physical properties of rhyolite rock (density, color, and absorption) was investigated in conjunction with its microstructural properties. The hardening of the rhyolitic rock samples was observed below 600 °C, at which point the UCS and elastic modulus decreased to 78.0% and 75.9%, respectively, at 800 °C. The results also show that heating does not significantly affect the density and volume of permeable pore space, but a color change can be observed at 400 °C and above. A microscopic analysis shows the change in microstructural properties of rhyolite rock after heating to 600 °C. Furthermore, the SEM observations of heated materials show structural particle displacements and microcracking, leading to apparent surface cracks

An Analytical Model for Transient Heat Transfer with a Time-Dependent Boundary in Solar- and Waste-Heat-Assisted Geothermal Borehole Systems: From Single to Multiple Boreholes

With the increasing engineering applications of geothermal borehole heat exchangers (BHEs), accurate and reliable mathematical models can help advance their thermal design and operations. In this study, an analytical model with a time-dependent heat flux boundary condition on the borehole wall is developed, capable of predicting the thermal performance of single, double, and multiple closed-loop BHEs, with an emphasis on solar- and waste-heat-assisted geothermal borehole systems (S-GBS and W-GBS) for energy storage. This analytical framework begins with a one-dimensional transient heat conduction problem subjected to a time-dependent heat flux for a single borehole. The single borehole scenario is then extended to multiple boreholes by exploiting lines of symmetry (or thermal superposition). A final expression of the temperature distribution along the center line is attained for single, double, and multiple boreholes, which is verified with a two-dimensional finite-element numerical model (less than 0.7% mean absolute deviation) and uses much lesser computational power and time. The analytical solution is also validated against a field-scale experiment from the literature regarding the borehole and ground temperatures at different time frames, with an absolute error below 6.3%. Further, the thermal performance of S-GBS and W-GBS is compared for a 3-by-3 borehole configuration using the analytical model to ensure its versatility in thermal energy storage. It is concluded that our proposed analytical framework can rapidly evaluate closed-loop geothermal BHEs, regardless of the numbers of boreholes and the type of the heat flux on the borehole wall.Applied Science, Faculty ofNon UBCMining Engineering, Keevil Institute ofReviewedFacult

Test-based De-isolation in COVID-19 Immunocompromised patients: Ct value versus SARS-CoV-2 viral cultures

Background Immunocompromised patients with coronavirus disease 2019 (COVID-19) have prolonged infectious viral shedding for more than 20 days. A test-based approach is suggested for de-isolation of these patients. Methods The strategy was evaluated by comparing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral load (cycle threshold (Ct) values) and viral culture at the time of hospital discharge in a series of 13 COVID-19 patients: six immunocompetent and seven immunocompromised (five solid organ transplant patients, one lymphoma patient, and one hepatocellular carcinoma patient). Results Three of the 13 (23%) patients had positive viral cultures: one patient with lymphoma (on day 16) and two immunocompetent patients (on day 7 and day 11). Eighty percent of the patients had negative viral cultures and had a mean Ct value of 20.5. None of the solid organ transplant recipients had positive viral cultures. Conclusions The mean Ct value for negative viral cultures was 20.5 in this case series of immunocompromised patients. Unlike those with hematological malignancies, none of the solid organ transplant patients had positive viral cultures. Adopting the test-based approach for all immunocompromised patients may lead to prolonged quarantine. Large-scale studies in disease-specific populations are needed to determine whether a test-based approach versus a symptom-based approach or a combination is applicable for the de-isolation of various immunocompromised patients