Effect of boron doping on optical properties of sol-gel based nanostructured zinc oxide films on glass

Boron doped zinc oxide thin films (∼80 nm) were deposited onto pure silica glass by sol-gel dip coating technique from the precursor sol/solution of 4.0 wt.% equivalent oxide content. The boron concentration was varied from 0 to 2 at.% w.r.t. Zn using crystalline boric acid. The nanostructured feature of the films was visualized by FESEM images and the largest cluster size of ZnO was found in 1 at.% boron doped film (B1ZO). The presence of mixed crystal phases with hexagonal as major phase was identified from XRD reflections of the films. Particle size, optical band gap, visible specular reflection, room temperature photoluminescence (PL) emissions (3.24-2.28 eV), infra-red (IR) and Raman active longitudinal optical (LO) phonon vibration were found to be dependent on dopant concentration. For the first time, we report the room temperature fine structured PL emissions as phonon replicas originated from the LO phonon (both IR and Raman active) in 1 at.% boron doped zinc oxide film.     

Biodegradable Polyesters and Low Molecular Weight Polyethylene in Soil: Interrelations of Material Properties,Soil Organic Matter Substances,and Microbial Community

Conventional and also biodegradable polymer microplastics have started to be broadly present in the environment, if they end up in soil, they may influence both abiotic and biotic soil properties. In this study, the interactions of polyethylene wax together with three biodegradable polyesters PLA, PHB and PBAT with a soil matrix were investigated over a 1-year incubation period. Soil organic matter content was measured using UV–VIS, the microbial biomass amount was measured using qPCR, the mineralisation of polymers was measured using UGA 3000, the surface of polymers was observed with SEM, live/dead microorganisms were determined by fluorescent microscopy and microbial consortia diversity was analyzed using NGS. The amount of humic substances was generally higher in incubations with slowly degrading polyesters, but the effect was temporary. The microbial biomass grew during the incubations; the addition of PHB enhanced fungal biomass whereas PE wax enhanced bacterial biomass. Fungal microbial consortia diversity was altered in incubations with PHB and PBAT. Interestingly, these two polyesters were also covered in biofilm, probably fungal. No such trend was observed in a metagenomic analysis of bacteria, although, bacterial biofilm was probably formed on the PE520 surface. Different methods confirmed the effect of certain polymers on the soil environment.     

Antibacterial and Antifouling Efficiency of Essential Oils-Loaded Electrospun Polyvinylidene Difluoride Membranes

Nanofibers have become a promising material in many industries in recent years, mainly due to their various properties. The only disadvantage of nanofibers as a potential filtration membrane is their short life due to clogging by bacteria in water treatment. The enrichment of nanofibers with active molecules could prevent these negative effects, represented by essential oils components such as Thymol, Eugenol, Linalool, Cinnamaldehyde and Carvacrol. Our study deals with the preparation of electrospun polyvinylidene difluoride (PVDF)-based nanofibers with incorporated essential oils, their characterization, testing their antibacterial properties and the evaluation of biofilm formation on the membrane surface. The study of the nanofibers’ morphology points to the nanofibers’ diverse fiber diameters ranging from 570 to 900 nm. Besides that, the nanofibers were detected as hydrophobic material with wettability over 130°. The satisfactory results of PVDF membranes were observed in nanofibers enriched with Thymol and Eugenol that showed their antifouling activity against the tested bacteria Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923. Therefore, these PVDF membranes could find potential applications as filtration membranes in healthcare or the environment.     

Ontology for maintenance of onshore wind turbines

Forschung im Ingenieurwesen - Operating and maintenance costs, which account for 25% of total costs, are a powerful lever in reducing the electricity generation costs of onshore wind...     

Evaluation of an onset of electrospun beadless poly(ethylene oxide) nanofibres

To evaluate the lowest polymer concentration within a solvent from which there appears beadless nanofibres during the process of electrospinning, is rather complicated. A widely used method is based on a determination of so called entanglement concentration c_e and the onsets of beadless nanofibres are characterized by multipliers of c_e subjected to used materials. However, a determination of c_e as an intersection point of two linear segments (in log–log coordinates specific viscosity vs. concentration) in a semi-dilute region is not applicable for all materials as for instance a solution of poly(ethylene oxide) (PEO) in water does not exhibit 'classical' three linear segments within the dilute and semi-dilute regions determining overlap and entanglement concentrations. For such cases a new approach for the evaluation of an initial concentration from which beadless nanofibres are produced is proposed. This method does not use the terms overlap and entanglement concentrations. The procedure is demonstrated using four PEO solutions differing in molecular weight. The relationship expressing initial concentration in dependence on PEO molecular weight containing no adjustable parameters is proposed.     

Surface polar charge induced Ni loaded CdS heterostructure nanorod for efficient photo-catalytic hydrogen evolution

Designing of artificial heterostructure photo-catalysts to crop solar energy for H₂ evolution from water is of great importance nowadays. The ultrafine Ni (0.5, 1.0, 2.0 and 5.0 wt%) particles loaded CdS nanorods were synthesized by a simple chemical process. XRD shows the crystalline phase of CdS with increase in size from 17 to 28 nm with 10.19% and 10.06% enhancement in the lattice strain and the dislocation density for Ni (0.5–5.0 wt%). The XPS peaks observed at 854.88 eV and 861.07 eV for Ni²⁺ with energy separation of 6.18 eV confirmed the existence of NiO on Ni surface. The Raman bands for pure CdS and Ni (1.0 wt%)-CdS nanorods were observed at 300 cm^?1 and 293 cm^?1 for 1LO phonon and 601 cm^?1 and 586 cm^?1 for 2LO phonon, respectively. The Ni loading tuned the CdS band gap from 2.36 to 2.20 eV. The eight fold enhancement in the CdS specific surface area i.e., from 4.19194 m² g^?1 to 34.8343 m² g^?1 was achieved. After Ni loading, the synergetic effect of efficient electron separation and transportation was observed by the continuous quenching of luminescence emission intensity and the reduction of charge transfer resistance from 706 Ω for CdS to 484 Ω of CdS. The Ni (1.0 wt%)@ NiO optimal loading on CdS results highest photo-catalytic H₂ evolution of 9.0 mmol at rate of 1.8 mmol h^?1, which is about 50 times higher than that of 180 μmol at rate of 36 μmol h^?1 for pure CdS. A thin layer of NiO on plasmonic Ni surface could be the promising system for photo-catalytic H₂ evolution due to visible light photo-activity.     

Endogenous Opioid Peptides and Alternatively Spliced Mu Opioid Receptor Seven Transmembrane Carboxyl-Terminal Variants

There exist three main types of endogenous opioid peptides, enkephalins, dynorphins and β-endorphin, all of which are derived from their precursors. These endogenous opioid peptides act through opioid receptors, including mu opioid receptor (MOR), delta opioid receptor (DOR) and kappa opioid receptor (KOR), and play important roles not only in analgesia, but also many other biological processes such as reward, stress response, feeding and emotion. The MOR gene, OPRM1, undergoes extensive alternative pre-mRNA splicing, generating multiple splice variants or isoforms. One type of these splice variants, the full-length 7 transmembrane (TM) Carboxyl (C)-terminal variants, has the same receptor structures but contains different intracellular C-terminal tails. The pharmacological functions of several endogenous opioid peptides through the mouse, rat and human OPRM1 7TM C-terminal variants have been considerably investigated together with various mu opioid ligands. The current review focuses on the studies of these endogenous opioid peptides and summarizes the results from early pharmacological studies, including receptor binding affinity and G protein activation, and recent studies of β-arrestin2 recruitment and biased signaling, aiming to provide new insights into the mechanisms and functions of endogenous opioid peptides, which are mediated through the OPRM1 7TM C-terminal splice variants.     

Pythagorean fuzzy Dombi aggregation operators and its applications in multiple attribute decision-making

The operations of -norm and -conorm, developed by Dombi, were generally known as Dombi operations, which may have a better expression of application if they are presented in a new form of flexibility within the general parameter. In this paper, we use Dombi operations to create a few Pythagorean fuzzy Dombi aggregation operators: Pythagorean fuzzy Dombi weighted average operator, Pythagorean fuzzy Dombi order weighted average operator, Pythagorean fuzzy Dombi hybrid weighted average operator, Pythagorean fuzzy Dombi weighted geometric operator, Pythagorean fuzzy Dombi order weighted geometric operator, and Pythagorean fuzzy Dombi hybrid weighted geometric operator. The distinguished feature of these proposed operators is examined. At that point, we have used these operators to build up a model to remedy the multiple attribute decision-making issues under Pythagorean fuzzy environment. Ultimately, a realistic instance is stated to substantiate the created model and to exhibit its applicability and viability.     

Mycobacterial Epoxide Hydrolase EphD Is Inhibited by Urea and Thiourea Derivatives

The genome of the human intracellular pathogen Mycobacterium tuberculosis encodes an unusually large number of epoxide hydrolases, which are thought to be involved in lipid metabolism and detoxification reactions needed to endure the hostile environment of host macrophages. These enzymes therefore represent suitable targets for compounds such as urea derivatives, which are known inhibitors of soluble epoxide hydrolases. In this work, we studied in vitro the effect of the thiourea drug isoxyl on six epoxide hydrolases of M. tuberculosis using a fatty acid substrate. We show that one of the proteins inhibited by isoxyl is EphD, an enzyme involved in the metabolism of mycolic acids, key components of the mycobacterial cell wall. By analyzing mycolic acid profiles, we demonstrate the inhibition of EphD epoxide hydrolase activity by isoxyl and two other urea-based inhibitors, thiacetazone and AU1235, inside the mycobacterial cell.     

Potential of teff (Eragrostis tef) flour as an ingredient in gluten-free cakes: chemical,technological and sensory quality

This article aimed to evaluate the chemical, technological and sensory characteristics of gluten-free cakes made with teff (Eragrostis tef). Four cakes were evaluated: T1, 100% teff flour; T2, 75% teff flour, 12.5% rice flour, 12.5% cassava starch; T3, 50% teff flour, 25% rice flour, 25% cassava starch and T4, 25% teff flour, 37.5% rice flour, 37.5% cassava starch. Higher percentages of teff increased total ash. For apparent and specific volumes, T4 was the one with the highest mean. In sensory analysis, the attributes of appearance, colour and odour did not have significant difference among treatments. T1 received the lowest overall average for flavour (5.03). Regarding the purchase intention, the cakes did not show significant difference between T3 and T2 (3.25 and 3.08). T2, T3 and T4 obtained acceptance index higher than 70%. The use of teff flour in cakes can be promising in gluten free diet.