Effective NiMn nanoparticles-functionalized carbon felt as an effective anode for direct urea fuel cells

The internal resistances of fuel cells strongly affect the generated power. Basically, in the fuel cell, the anode can be prepared by deposition of a film from the functional electrocatalyst on a proper gas diffusion layer. Accordingly, an interfacial resistance for the electron transport is created between the two layers. Electrocatalyst-functionalized gas diffusion layer (GDL) can distinctly reduce the interfacial resistance between the catalyst layer and the GDL. In this study, NiMn nanoparticles-decorated carbon felt is introduced as functionalized GDL to be exploited as a ready-made anode in a direct urea fuel cell. The proposed treated GDL was prepared by calcination of nickel acetate/manganese acetate-loaded carbon felt under an argon atmosphere at 850 °C. The physiochemical characterizations confirmed complete reduction for the utilized precursors and deposition of pristine NiMn nanoparticles on the carbon felt fiber. In passive direct urea fuel cells, investigation the performance of the functionalized GDLs indicated that the composition of the metal nanoparticles has to be optimized as the GDL obtained from 40 wt % manganese acetate reveals the maximum generated power density; 36 mW/m2 at room temperature and 0.5 M urea solution. Moreover, the electrochemical measurements proved that low urea solution concentration is preferred as utilizing 0.5 M solution resulted into generating higher power compared to 1.0 and 2.0 M solution. Overall, this study opens a new avenue toward functionalization of the GDL as a novel strategy to overcome the interfacial resistance between the electrocatalyst and the GDL. View Full-TextFunding: This publication was made possible by NPRP grant # [8-1344-1-246] from Qatar National Research Fund (a member of Qatar Foundation). The findings achieved herein are solely the responsibility of authors. Acknowledgments: All authors gratefully acknowledge the support of Qatar Foundation.Scopu

Influence of seed layer thickness on properties of electrodeposited ZnO nanostructured films

[EN] The quality and properties of electrodeposited nanostructured ZnO films are improved when they are deposited on a crystal lattice-matching substrate. To this end, a highly conductive indium tin oxide substrate is covered with an interlayer of ZnO using direct-current magnetron sputtering. In this manuscript, we describe the effect of this interlayer on the morphological and optical properties of several nanostructured ZnO films grown by different electrodeposition methods. The thickness of the ZnO interlayer was varied starting from ultrathin layers of 10 nm all the way up to 230 nm as determined by ellipsonnetry. The structural and optical properties of the nanostructured ZnO films deposited on top of these interlayers were characterized using field emission scanning electron microscopy (FESEM), atomic force microscopy and UV-visible spectroscopy. Optimum properties of the nanostructured ZnO films for application in thin-film optoelectronic devices are obtained when the ZnO interlayer has a thickness of approximately 45 nm. This is the case for all the electrodeposition methods used in this work.Reyes Tolosa, MD.; Alajami, M.; Montero Reguera, ÁE.; Damonte, L.; Hernández Fenollosa, MDLÁ. (2019). Influence of seed layer thickness on properties of electrodeposited ZnO nanostructured films. SN Applied Sciences. 1(10):1-9. https://doi.org/10.1007/s42452-019-1293-719110Marotti RE, Giorgi P, Machado G, Dalchiele EA (2006) Crystallite size dependence of band gap energy for electrodeposited ZnO grown at different temperatures. Sol Energy Mater Sol Cells 90:2356–2361Marotti RE, Guerra DN, Bello C, Machado G (2004) Bandgap energy tuning of electrochemically grown ZnO thin films by thickness and electrodeposition potential. 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Influence of seed layer thickness on properties of electrodeposited ZnO nanostructured films

The quality and properties of electrodeposited nanostructured ZnO films are improved when they are deposited on a crystal lattice-matching substrate. To this end, a highly conductive indium tin oxide substrate is covered with an interlayer of ZnO using direct-current magnetron sputtering. In this manuscript, we describe the effect of this interlayer on the morphological and optical properties of several nanostructured ZnO films grown by different electrodeposition methods. The thickness of the ZnO interlayer was varied starting from ultrathin layers of 10 nm all the way up to 230 nm as determined by ellipsometry. The structural and optical properties of the nanostructured ZnO films deposited on top of these interlayers were characterized using field emission scanning electron microscopy (FESEM), atomic force microscopy and UV–visible spectroscopy. Optimum properties of the nanostructured ZnO films for application in thin-film optoelectronic devices are obtained when the ZnO interlayer has a thickness of approximately 45 nm. This is the case for all the electrodeposition methods used in this work.Facultad de Ciencias ExactasInstituto de Física La Plat

Molecular detection of Leishmania species in Sand Flies by PCR-RFLP technique in refugee camps

ABSTRACT Leishmaniasis is one of the most important health dilemmas facing the World Health Organization (WHO), due to it being widespread and the great diversity of sand flies that transmit it. This study aimed to detect the presence of Leishmania parasites in the sand flies spread in Refugee camps by PCR- RLFP technique. A total of 437 sandflies were collected and classified into two species Phlebotomus papatasi and Phlebotomus sergenti. DNA was extracted from the female fly species, then the PCR reaction was amplified by two primers (LITSR, L5.8S) that transcribed a partial internal transcribed spacer (ITS)-1 gene for Leishmania parasite with a length of 320 bp. PCR showed the presence of Leishmania DNA in females of both P. papatasi (10%) and P. sergenti (20%). To determine Leishmania species transmitted by the two previous fly species, the RFLP-PCR technique was performed by the HaeIII enzyme for Leishmania DNA extracted from them. RFLP-PCR showed that P. papatasi females transmitted Leishmania major and P. sergenti females transmitted Leishmania tropica in Refugee camps. It could be concluded that leishmaniasis is widely distributed in Refugee camps due to the presence of its vector

Sustainability Reporting and Bank Performance After Financial Crisis: Evidence from Developed and Developing Countries

Purpose This study aims to examine the relationship between sustainability reporting and bank performance after financial crisis in developed and developing countries. Design/methodology/approach This study examines 882 banks from developed and developing countries covering 11 years after the 2008 financial crisis. The independent variable is environmental, social and governance (ESG) scores. The dependent variables are return on assets, return on equity and Tobin’s Q. This study uses bank- and country-specific control variables to measure the relationship between sustainability reporting and bank performance. Findings The findings deduced from the empirical results demonstrate that ESG improves banks’ accounting and market-based performance in developed countries, supporting value creation theory. Using pooling regression and instrumental variable – generalized method of moments, this study finds that ESG weakens banks’ performance in developed and developing countries. Originality/value To the best of the author’s knowledge, this is the first study to investigate and compare the impact of sustainability reporting on banks’ performance in developed and developing countries. The study found similarities in the impact of sustainability reporting and the improvement of banks’ current and future performance

Effective NiMn Nanoparticles-Functionalized Carbon Felt as an Effective Anode for Direct Urea Fuel Cells

The internal resistances of fuel cells strongly affect the generated power. Basically, in the fuel cell, the anode can be prepared by deposition of a film from the functional electrocatalyst on a proper gas diffusion layer. Accordingly, an interfacial resistance for the electron transport is created between the two layers. Electrocatalyst-functionalized gas diffusion layer (GDL) can distinctly reduce the interfacial resistance between the catalyst layer and the GDL. In this study, NiMn nanoparticles-decorated carbon felt is introduced as functionalized GDL to be exploited as a ready-made anode in a direct urea fuel cell. The proposed treated GDL was prepared by calcination of nickel acetate/manganese acetate-loaded carbon felt under an argon atmosphere at 850 °C. The physiochemical characterizations confirmed complete reduction for the utilized precursors and deposition of pristine NiMn nanoparticles on the carbon felt fiber. In passive direct urea fuel cells, investigation the performance of the functionalized GDLs indicated that the composition of the metal nanoparticles has to be optimized as the GDL obtained from 40 wt % manganese acetate reveals the maximum generated power density; 36 mW/m2 at room temperature and 0.5 M urea solution. Moreover, the electrochemical measurements proved that low urea solution concentration is preferred as utilizing 0.5 M solution resulted into generating higher power compared to 1.0 and 2.0 M solution. Overall, this study opens a new avenue toward functionalization of the GDL as a novel strategy to overcome the interfacial resistance between the electrocatalyst and the GDL

High-quality genome assembly and annotation of five bacteria isolated from the Abu Dhabi sabkha-shore region

Abstract Objectives Sabkhas represent polyextreme environments characterized by elevated salinity levels, intense ultraviolet (UV) radiation exposure, and extreme temperature fluctuations. In this study, we present the complete genomes of five bacterial isolates isolated from the sabkha-shore region and investigate their genomic organization and gene annotations. A better understanding of the bacterial genomic organization and genetic adaptations of these bacteria holds promise for engineering microbes with tailored functionalities for diverse industrial and agricultural applications, including bioremediation and promotion of plant growth under salinity stress conditions. Data description We present a comprehensive genome sequencing and annotation of five bacteria (kcgeb_sa, kcgeb_sc, kcgeb_sd, kcgeb_S4, and kcgeb_S11) obtained from the shores of the Abu Dhabi Sabkha region. Initial bacterial identification was conducted through 16 S rDNA amplification and sequencing. Employing a hybrid genome assembly technique combining Illumina short reads (NovaSeq 6000) and Oxford Nanopore long reads (MinION), we obtained complete annotated high-quality gap-free genome sequences. The genome sizes of the kcgeb_sa, kcgeb_sc, kcgeb_sd, kcgeb_S4, and kcgeb_S11 isolates were determined to be 2.4 Mb, 4.1 Mb, 2.9 Mb, 5.05 Mb, and 4.1 Mb, respectively. Our analysis conclusively assigned the bacterial isolates as Staphylococcus capitis (kcgeb_sa), Bacillus spizizenii (kcgeb_sc and kcgeb_S11), Pelagerythrobacter marensis (kcgeb_sd), and Priestia aryabhattai (kcgeb_S4)

A comparison of three thromboprophylaxis regimens in critically ill COVID-19 patients: An analysis of real-world data

Introduction: Thrombotic complications of coronavirus disease 2019 (COVID-19) have received considerable attention. Although numerous conflicting findings have compared escalated thromboprophylaxis doses with a standard dose to prevent thrombosis, there is a paucity of literature comparing clinical outcomes in three different anticoagulation dosing regimens. Thus, we investigated the effectiveness and safety profiles of standard, intermediate, and high-anti-coagulation dosing strategies in COVID-19 critically ill patients. Methodology: This retrospective multicenter cohort study of intensive care unit (ICU) patients from the period of April 2020 to August 2021 in four Saudi Arabian centers. Inclusion criteria were age ≥ 18 years, diagnosis with severe or critical COVID-19 infection, and receiving prophylactic anticoagulant dose within 24–48 h of ICU admission. The primary endpoint was a composite of thrombotic events, with mortality rate and minor or major bleeding serving as secondary endpoints. We applied survival analyses with a matching weights procedure to control for confounding variables in the three arms. Results: A total of 811 patient records were reviewed, with 551 (standard-dose = 192, intermediate-dose = 180, and high-dose = 179) included in the analysis. After using weights matching, we found that the standard-dose group was not associated with an increase in the composite thrombotic events endpoint when compared to the intermediate-dose group {19.8 vs. 25%; adjusted hazard ratio (aHR) =1.46, [95% confidence of interval (CI), 0.94–2.26]} or when compared to high-dose group [19.8 vs. 24%; aHR = 1.22 (95% CI, 0.88–1.72)]. Also, there were no statistically significant differences in overall in-hospital mortality between the standard-dose and the intermediate-dose group [51 vs. 53.4%; aHR = 1.4 (95% CI, 0.88–2.33)] or standard-dose and high-dose group [51 vs. 61.1%; aHR = 1.3 (95% CI, 0.83–2.20)]. Moreover, the risk of major bleeding was comparable in all three groups [standard vs. intermediate: 4.8 vs. 2.8%; aHR = 0.8 (95% CI, 0.23–2.74); standard vs. high: 4.8 vs. 9%; aHR = 2.1 (95% CI, 0.79–5.80)]. However, intermediate-dose and high-dose were both associated with an increase in minor bleeding incidence with aHR = 2.9 (95% CI, 1.26–6.80) and aHR = 3.9 (95% CI, 1.73–8.76), respectively. Conclusion: Among COVID-19 patients admitted to the ICU, the three dosing regimens did not significantly affect the composite of thrombotic events and mortality. Compared with the standard-dose regimen, intermediate and high-dosing thromboprophylaxis were associated with a higher risk of minor but not major bleeding. Thus, these data recommend a standard dose as the preferred regimen. Copyright © 2022 Alrashed, Cahusac, Mohzari, Bamogaddam, Alfaifi, Mathew, Alrumayyan, Alqahtani, Alshammari, AlNekhilan, Binrokan, Alamri, Alshahrani, Alshahrani, Alanazi, Alhassan, Alsaeed, Almutairi, Albujaidy, AlJuaid, Almalki, Ahmed, Alajami, Aljishi, Alsheef, Alajlan, Almutairi, Alsirhani, Alotaibi, Aljaber, Bahammam, Aldandan, Almulhim, Abraham and Alamer.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]