Response of Generalized Thermoelastic Half-space with Voids to Mechanical and Thermal sources

The dynamic response of a homogeneous, isotropic, generalized thermoelastic half-space with voids subjected to normal, tangential force and thermal source is investigated. The displacements, stresses, temperature distribution and change in volume fraction field so obtained in the physical domain are computed numerically and illustrated graphically. The numerical results of these quantities for magnesium crystal-like material are illustrated to depict the response of various sources in the Lord–Shulman (L–S) theory and Green–Lindsay (G–L) theory for an insulated boundary and temperature gradient boundary. Some particular cases have been deduced.     

Voice Changes During Work: Subjective Complaints and Objective Measurements for Female Primary and Secondary Schoolteachers

The purpose of this investigation was to study voice changes during a working day. The subjects consisted of 33 female primary and secondary schoolteachers who recorded their first and last lessons during one school day. The subjects were studied both as one group and two subgroups (those with many and those with few voice complaints). Estimates of fundamental frequency (F0), sound pressure level (SPL), the standard deviations of these values (F0 SD; SPL SD) and F0 time (vibration time of vocal folds) were made. The most obvious change due to loading was the rise of F0 that was 9.7 Hz between the first and last lesson (P = 0.00). F0 increased more (12.8. Hz, P = 0.006) in the subgroup with few complaints.     

Identification of Antiviral Compounds against Monkeypox Virus Profilin-like Protein A42R from Plantago lanceolata

Infections caused by the monkeypox virus (MPXV) have continued to be transmitted significantly in recent years. However, understanding the transmission mechanism, risk factors, and consequences of infection are still limited. Structure-based drug design for MPXV is at an early stage due to the availability of protein structures that have been determined experimentally. However, the structure of the A42R profilin-like protein of MPXV has been solved and submitted to the structure database. This study illustrated an in silico structure-based approach to identify the potential hit compound against A42R of MPXV. Here, 65 Plantago lanceolata compounds were computationally screened against A42R of MPXV. Virtual screening identified top five hits (i) Luteolin 7,3′-Diglucuronide (PubChem ID: 44258091), (ii) Luteolin 7-Glucuronide-3′-Glucoside (PubChem ID: 44258090), (iii) Plantagoside (PubChem ID: 174157), (iv) Narcissoside (PubChem ID: 5481663), and (v) (AlphaE,8S,9R)-N-(3,4-Dihydroxyphenethyl)-8-[(3,4-Dihydroxyphenethyl)Carbamoyl]-9-(1,3-Benzodioxole-5-Yl)-3aalpha,7aalpha-Ethano-1,3-Benzodioxole-5-Acrylamide (PubChem ID: 101131595), with binding energy <−9.0 kcal/mol that was further validated by re-docking and molecular dynamic (MD) simulation. Interaction analysis of re-docked poses confirmed the binding of these top hits to the A42R protein as reported in the reference compound, including active residues ARG114, ARG115, and ARG119. Further, MD simulation and post-simulation analysis support Plantagoside and Narcissoside for substantial stability in the binding pocket of viral protein contributed by hydrogen and hydrophobic interactions. The compounds can be considered for further optimisation and in vitro experimental validation for anti-monkeypox drug development.     

Preparation of aqueous crosslinked dispersions of functionalized poly(d,l-lactic acid) with a thermomechanical method

Aqueous crosslinked microparticle dispersions were prepared from a copolymer of d,l-lactic acid, 1,4-butanediol, and itaconic acid with a thermomechanical method. The copolymer was prepared in one step polycondensation reaction using Sn(Oct)₂ as a catalyst. A polymer with M_n of 2800 g mol^?1 and a molecular weight distribution of 1.41 was obtained (as determined by SEC), that contained double bonds introduced by the itaconic acid monomer units (6 mol-%, as determined by NMR). Crosslinking ability of the prepared copolymer was demonstrated in bulk by adding a thermal initiator and altering amounts of ethylene glycol dimethacrylate (EGDMA) crosslinking agent into molten polymer at 60–150 °C. A crosslinked gel was formed in less than 15 min at 80 °C when 10 wt.% of EGDMA was added and benzoyl peroxide (BPO) was used as the initiator. Aqueous dispersions were prepared of the non-crosslinked copolymer with a thermomechanical method that involved slow addition of aqueous polyvinyl alcohol (PVA) solution into molten copolymer at 60 °C under shear. Dispersions were prepared with 10 wt.% of EGDMA and 2 wt.% of BPO. Crosslinking of the dispersed microparticles was achieved by heating the dispersions at 80 °C for 30 or 60 min. The dispersions were characterized by SEM, DSC, TGA, FT-IR, solid state NMR, and gel content measurements. The effect of crosslinking was clearly seen in SEM images of films cast from the dispersions. The films cast from non-crosslinked dispersions had smooth morphology whereas in films cast from crosslinked dispersions separate spherical particles were observed. During the crosslinking reactions, glass transition temperatures increased (as determined by DSC), thermal stability of the samples increased (as determined by TGA), and the gel content of the samples increased.     

Polymeric stabilization of hybrid nanocomposites: a comparison between in situ and ex situ-grown CuInS2 in poly(3-hexylthiophene) polymer

CuInS₂ (CIS) particles were directly synthesized in P3HT matrix with different concentrations ratio of P3HT and CIS (1:2, 1:4, and 1:8) by decomposition of copper indium xanthate (CIX). Here, copper indium xanthate and P3HT were mixed homogeneously in o-dichlorobenzene (DCB), which induced the formation of the CIS nanoparticles by the thermal decomposition of the precursor compound in situ at temperatures as low as 110 °C. The effects of the precursor concentration on the size of the CIS nanoparticles was studied by microstructure investigations (TEM, AFM, XRD) and UV–vis measurements show that these CIS composites possess a direct bandgap energy higher than 1.45 eV depending on the concentration of P3HT. PL quenching of P3HT polymer (i.e., higher accessible fraction of fluorophores) was found to be more for in situ rather than ex situ conditions for comparable CIX concentrations or particle size. This can be attributed to the fact that in in situ synthesis, P3HT act as surface directing template for CIS nanoparticles which is not so in the case of ex situ synthesis. Due to this, the polymeric stabilization of the CIS nanocomposites is better realized for in situ synthesis as compared to ex situ synthesis.     

Poly(ether ether ketone)‐bischromenes: Synthesis,characterization, and influence on thermal,mechanical, and thermo mechanical properties of epoxy resin

Poly(ether ether ketone) s with terminal propargyl groups (PEEK‐PR) were synthesized from hydroxyl terminated PEEK (PEEKTOH) and characterized. The heat‐triggered polymerization of PEEK‐PR to poly bischromenes having PEEK backbone was confirmed by Fourier transform infrared spectroscopy and differential scanning calorimetric studies. PEEK‐PR was blended with a bisphenol based epoxy resin‐diamino diphenylsulphone system in different proportions and cured to form PEEK‐bischromene‐interpenetrated‐epoxy‐amine networks. Tensile strength and elongation of the cured blends increased up to 10‐phr loading of PEEK‐PR and then declined. Tensile moduli of all formulations were comparable. Fracture toughness increased by a maximum of 33%, and the fractured surface morphology showed a ductile fracture. The blends exhibited slightly lower glass transition temperature to that of the neat epoxy‐amine system. A reference sample of epoxy‐amine was processed with the optimum loading of the precursor polymer, PEEKTOH, and compared its properties with the PEEK‐PR incorporated epoxy systems. In this way, it is found that the incorporation of addition curable propargylated PEEK increases the strength characteristics with adequate thermal stability and fracture toughness for high‐performance structural applications.     

Photocatalytic decolouration,degradation and disinfection capability of Ag2CO3/ZnO in natural sunlight

In this study, a series of hybrid Ag₂CO₃/ZnO composites were synthesised via a simple precipitation route and investigated for discolouration-degradation of Methylene Blue and disinfection of Escherichia coli in natural sunlight. It was observed that the photonic efficiency of discolouration was more than 6 times that of the conventionally popular TiO₂, under experimental conditions; 100% Total Organic Carbon reduction was observed in 30 ?min and 32% disinfection in an hour. This upswing in the performance is attributed to favourable modulation of the dynamics of charge transfer. The photocatalysts were characterized by X-Ray Diffraction, Scanning Electron Microscopy, Transmission Electron Microscopy, Brunauer, Emmett and Teller and Ultraviolet–Visible-Near-InfraRed Spectroscopy. An equitable photocatalyst functional mechanism has also been proposed on the basis of Tauc plot and scavenging experiments. The effect of influencing parameters has also been investigated and reported in terms of photonic efficiency. Since the entire study is carried out in direct sunlight, it inherently supports realizable solar energy applications in wastewater treatment.     

Adsorption of Polycation and Anionic Surfactant onto Iron Surfaces and the Inhibition of Carbon Dioxide Corrosion

The adsorption process of two polycations (pDADMAC and C‐PAM) with different charge densities has been investigated using the quartz crystal microbalance technique with dissipation monitoring (QCM‐D). The effect of the charge density of the polycation, the NaCl concentration, and the complexation with an anionic surfactant are addressed in this work. X‐ray photoelectron spectroscopy and atomic force microscopy were utilized to analyze the adsorbate with respect to the film coverage and film structure. The corrosion‐inhibiting performance of the films on high‐purity iron in a CO₂ saturated brine, at 25°C, 1 bar CO₂, and pH 4, was investigated by the linear polarization resistance technique. It was found that the polycations adsorbed onto the iron surface, but the corrosion rate of 1 mm yr^?1 was not lowered. However, the polycations formed a complex with an anionic surfactant, and such films showed excellent inhibition performance. Both films, of pDADMAC/SDS and of C‐PAM/SDS, lowered the corrosion rate of iron below 0.01 mm yr^?1. The SDS concentration was below the cmc. It is believed that the SDS adsorbed into the preadsorbed polycation film, forming a complex structure resulting in a hydrophobic and dense film.