Optimizing Lead-free MASnBr3 Perovskite Solar Cells for High-Efficiency and Long-Term Stability Using Graphene and Advanced Interface Layers

Perovskite solar cells (PSCs) have garnered significant attention in the scientific community due to their rapid increase in performance. Inorganic perovskite devices have been noted for their high performance and long-term stability. This study introduces a device optimization process guided by modeling to produce high-efficiency PSCs using lead-free n-i-p methylammonium tin bromide (MASnBr3) materials. We have thoroughly examined the impact of both the absorber and interface layers on the optimized structure. Our approach utilized graphene as the interface layer between the hole transport and absorber layers. We employed zinc oxide (ZnO)/Al and 3C-SiC as interface layers between the absorber and electron transport layers. The optimization process involved adjusting the thicknesses of the absorber layer and interface layers and minimizing defect densities. Our proposed optimized device structure, ZnO/3C-SiC/MASnBr3/graphene/CuO/Au, demonstrates theoretical power conversion efficiencies of 31.97%, fill factors of 89.38%, a current density of 32.54 mA/cm2, a voltage of 1.112 V, and a quantum efficiency of 94%. This research underscores the ability of MASnBr3 as a nontoxic perovskite material for sustainable energy from renewable sources' applications

Effectiveness of Antibiotic Prophylaxis for Leptospirosis among Adults: A Systematic Review

Leptospirosis is one of the most widespread re-emerging zoonoses in the world. Malaysia is known to be an endemic country for human leptospirosis, with a case fatality rate of 2.11%, and an average annual incidence rate of 7.80 cases per 100,000 individuals. This systematic review is conducted to determine the effectiveness of antibiotic prophylaxis for leptospirosis among the adult populations who are highly at risk of getting infected. A systematic search was performed for the relevant titles, abstracts and keywords on PubMed, Scopus, Cochrane and Google Scholar from inception to November 2017 based on the PICO strategy; which returned 126 studies. Screening of abstracts had shortlisted 19 studies and data extraction was conducted for 8 studies which had been accepted after review of the full text. For the evaluation of antibiotics prophylaxis effectiveness against leptospirosis, only trials and cohort studies with risk ratio (RR) were selected. The articles were analyzed from the viewpoint of the dosage, adverse effects, study settings and effectiveness of the antibiotic prophylaxis. Using fixed effects model, pooled RR showed protective association between antibiotic prophylaxis use against the incidence of leptospirosis (RR = 0.31; 95% CI: 0.20, 0.48). Antibiotic prophylaxis for leptospirosis had been shown to be effective in preventing the incidence of the disease among high-risk populations and carries minimal adverse effects. It is recommended that the practice of antibiotic prophylaxis for leptospirosis is included in the standard protocol for leptospirosis prevention among people at high-risk, including disaster response teams and patrons of eco-sports tourism activities; with the drug of choice being doxycycline, either as a single 200 mg dose or weekly dose of 200 mg for the duration of exposure, based on the setting, duration of event and resources available

Recent progress in two dimensional Mxenes for photocatalysis: a critical review

Transition metal carbides and nitrides, generally known as MXenes have emerged as an alternative to improve photocatalytic performance in renewable energy and environmental remediation applications because of their high surface area, tunable chemistry, and easily adjustable elemental compositions. MXenes have many interlayer groups, surface group operations, and a flexible layer spacing that makes them ideal catalysts. Over 30 different members of the MXenes family have been explored and successfully utilized as catalysts. Particularly, MXenes have achieved success as a photocatalyst for carbon dioxide reduction, nitrogen fixation, hydrogen evolution, and photochemical degradation. The structure of MXenes and the presence of hydrophilic functional groups on the surface results in excellent photocatalytic hydrogen evolution. In addition, MXenes’ surface defects provide abundant CO2 adsorption sites. Moreover, their highly efficient catalytic oxidation activity is a result of their excellent two-dimensional nanomaterial structure and high-speed electron transport channels. This article comprehensively discusses the structure, synthesis techniques, photocatalytic applications (i.e. H2 evolution, N2 fixation, CO2 reduction, and degradation of pollutants), and recyclability of MXenes. This review also critically evaluates the MXene-based heterostructure and composites photocatalyst synthesis process and their performance for organic pollutant degradation. Finally, a prospect for further research is presented in environmental and energy sciences

Antibacterial properties of tualang honey and its effect in burn wound management: a comparative study

<p>Abstract</p> <p>Background</p> <p>The use of honey as a natural product of <it>Apis </it>spp. for burn treatment has been widely applied for centuries. Tualang honey has been reported to have antibacterial properties against various microorganisms, including those from burn-related diagnoses, and is cheaper and easier to be absorbed by Aquacel dressing. The aim of this study is to evaluate the potential antibacterial properties of tualang honey dressing and to determine its effectiveness as a partial thickness burn wound dressing.</p> <p>Methods</p> <p>In order to quantitate the bioburden of the swabs, pour plates were performed to obtain the colony count (CFU/ml). Swabs obtained from burn wounds were streaked on blood agar and MacConkey agar for bacterial isolation and identification. Later, antibacterial activity of Aquacel-tualang honey, Aquacel-Manuka honey, Aquacel-Ag and Aquacel- plain dressings against bacteria isolated from patients were tested (<it>in-vitro</it>) to see the effectiveness of those dressings by zone of inhibition assays.</p> <p>Results</p> <p>Seven organisms were isolated. Four types of Gram-negative bacteria, namely <it>Enterobacter cloacae</it>, <it>Klebsiella pneumoniae</it>, <it>Pseudomonas </it>spp. and <it>Acinetobacter </it>spp., and three Gram-positive bacteria, namely <it>Staphylococcus aureus</it>, coagulase-negative <it>Staphylococcus aureus </it>(CONS) and <it>Streptococcus </it>spp., were isolated. Total bacterial count decreased on day 6 and onwards. In the <it>in-vitro </it>antibacterial study, Aquacel-Ag and Aquacel-Manuka honey dressings gave better zone of inhibition for Gram positive bacteria compared to Aquacel-Tualang honey dressing. However, comparable results were obtained against Gram negative bacteria tested with Aquacel-Manuka honey and Aquacel-Tualang honey dressing.</p> <p>Conclusions</p> <p>Tualang honey has a bactericidal as well as bacteriostatic effect. It is useful as a dressing, as it is easier to apply and is less sticky compared to Manuka honey. However, for Gram positive bacteria, tualang honey is not as effective as usual care products such as silver-based dressing or medical grade honey dressing.</p

A periglacial palaeoenvionment in the Upper Carboniferous-Lower Permian Tobra Formation of the Salt Range, Pakistan

The Upper Carboniferous–Lower Permian (Upper Pennsylvanian–Asselian) Tobra Formation is exposed in the Salt and Trans Indus ranges of Pakistan. The formation exhibits an alluvial plain (alluvial fan–piedmont alluvial plain) fades association in the Salt Range and Khisor Range. In addition, a stream flow facies association is restricted to the eastern Salt Range. The alluvial plain facies association is comprised of clast-supported massive conglomerate (Gmc), diamictite (Dm) facies, and massive sandstone (Sm) lithofacies whereas the stream flow-dominated alluvial plain facies association includes fine-grained sandstone and siltstone (Fss), fining upwards pebbly sandstone (Sf), and massive mudstone (Fm) lithofacies. The lack of glacial signatures (particularly glacial grooves and striations) in the deposits in the Tobra Formation, which are, in contrast, present in their time-equivalent and palaeogeographically nearby strata of the Arabian peninsula, e.g. the Al Khlata Formation of Oman and Unayzah B member of the Saudi Arabia, suggests a pro- to periglacial, i.e. glaciofluvial depositional setting for the Tobra Formation. The sedimentology of the Tobra Formation attests that the Salt Range, Pakistan, occupied a palaeogeographic position just beyond the maximum glacial extent during Upper Pennsylvanian–Asselian time

Recent progress in two dimensional Mxenes for photocatalysis : a critical review

Transition metal carbides and nitrides, generally known as MXenes have emerged as an alternative to improve photocatalytic performance in renewable energy and environmental remediation applications because of their high surface area, tunable chemistry, and easily adjustable elemental compositions. MXenes have many interlayer groups, surface group operations, and a flexible layer spacing that makes them ideal catalysts. Over 30 different members of the MXenes family have been explored and successfully utilized as catalysts. Particularly, MXenes have achieved success as a photocatalyst for carbon dioxide reduction, nitrogen fixation, hydrogen evolution, and photochemical degradation. The structure of MXenes and the presence of hydrophilic functional groups on the surface results in excellent photocatalytic hydrogen evolution. In addition, MXenes' surface defects provide abundant CO2 adsorption sites. Moreover, their highly efficient catalytic oxidation activity is a result of their excellent two-dimensional nanomaterial structure and high-speed electron transport channels. This article comprehensively discusses the structure, synthesis techniques, photocatalytic applications (i.e. H-2 evolution, N-2 fixation, CO2 reduction, and degradation of pollutants), and recyclability of MXenes. This review also critically evaluates the MXene-based heterostructure and composites photocatalyst synthesis process and their performance for organic pollutant degradation. Finally, a prospect for further research is presented in environmental and energy sciences

Synthesis and Characterization of Manganese-Modified Black TiO2 Nanoparticles and Their Performance Evaluation for the Photodegradation of Phenolic Compounds from Wastewater

The release of phenolic-contaminated treated palm oil mill effluent (TPOME) poses a severe threat to human and environmental health. In this work, manganese-modified black TiO2 (Mn-B-TiO2) was produced for the photodegradation of high concentrations of total phenolic compounds from TPOME. A modified glycerol-assisted technique was used to synthesize visible-light-sensitive black TiO2 nanoparticles (NPs), which were then calcined at 300 &deg;C for 60 min for conversion to anatase crystalline phase. The black TiO2 was further modified with manganese by utilizing a wet impregnation technique. Visible light absorption, charge carrier separation, and electron&ndash;hole pair recombination suppression were all improved when the band structure of TiO2 was tuned by producing Ti3+ defect states. As a result of the enhanced optical and electrical characteristics of black TiO2 NPs, phenolic compounds were removed from TPOME at a rate of 48.17%, which is 2.6 times higher than P25 (18%). When Mn was added to black TiO2 NPs, the Ti ion in the TiO2 lattice was replaced by Mn, causing a large redshift of the optical absorption edges and enhanced photodegradation of phenolic compounds from TPOME. The photodegradation efficiency of phenolic compounds by Mn-B-TiO2 improved to 60.12% from 48.17% at 0.3 wt% Mn doping concentration. The removal efficiency of phenolic compounds from TPOME diminished when Mn doping exceeded the optimum threshold (0.3 wt%). According to the findings, Mn-modified black TiO2 NPs are the most effective, as they combine the advantages of both black TiO2 and Mn doping