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In the current study, the ability of an indigenous marine Actinomycete Nocardiopsis dassonvillei (NCIM 5124) to degrade poly(3-hydroxybutyrate)-PHB was examined. From the whole genome sequencing data of the organism, information regarding the PHB depolymerase gene and amino acid sequence (Accession number: MCK9871921.1) was retrieved. In silico studies indicated the presence of a signal peptide characteristic of extracellular enzymes. ProtParam tool predicted that the protein had a molecular mass of 42.46 kDa with an isoelectric point of 4.51. Aliphatic and instability index values suggested that the protein was stable and the observed GARVY value indicated its hydrophilic nature. 3D structure prediction and multiple sequence alignments revealed the presence of Type I catalytic domain [including the oxyanion histidine towards the N terminal, the catalytic triad with serine (as a part of GLSAG pentapeptide), aspartate and histidine], substrate binding and linker domain. The organism was able to grow on PHB in solid and liquid media and effectively degrade it. Maximum enzyme activity (1.8 U/mL/min) was observed after 5 d of incubation in Bushnell Hass Medium containing 0.1% PHB, 1.5% sodium chloride, at 30 °C, pH 7.5 with agitation at 130 rpm. Application of the organism in disintegrating films of PHB and its copolymers was successfully demonstrated on the basis of weight loss and scanning electron microscope analysis. To the best of our knowledge, this is the first report on production of PHB depolymerase with high efficiency by N. dassonvillei, an organism that holds promise in degrading PHB-derived waste material. [ABSTRACT FROM AUTHOR]

Silver nanowires (AgNWs) have excellent flexibility, unique optical transmittance and high conductivity. The polyol process is appropriate for preparing AgNWs due to its simplicity, effectiveness, low cost, and high yield. This work aims to investigate the effect of preparation parameters of the polyol process on the silver nanowires properties. The parameters include the controlling agent, molecular weight of the polyvinylpyrrolidone (PVP), the temperature, and the reducing agent. The amount of silver nanoparticles formed during preparation was used to determine the optimum preparation conditions. The transmission electron microscope (TEM) images showed minimal amount of Ag nanoparticles when using mixed molecular weight of PVP-40K, and PVP-1.3M at 150 °C with the assistance of copper chloride as a controlling agent. The prepared AgNWs had an average length of 3.7 µm and aspect ratio of 15.3. The fabricated electrodes were characterized using a scanning electron microscope (SEM) and four probe resistivity measurements. The electrical measurement of the AgNWs electrodes indicated that the surfactant thickness is a critical parameter in having low sheet resistance electrodes. Also, the optical transmission was affected by the amount of nanoparticles. The prepared electrode with high concentration of AgNWs and a minimal amount of nanoparticles exhibited 80% optical transmission. [ABSTRACT FROM AUTHOR]

Single-layer isophorone diisocyanate (IPDI) are one of the most popular self-healing microcapsules but suffers from low shell strength, poor heat resistance, stability and aging properties. In this paper, IPDI microcapsules were encapsulated into double-layer phenolic (PF)/polyurethane (PU) by a two-step process involving interfacial polymerization and in-situ polymerization. The prepared microcapsule composites were comprehensively characterized for their physical and chemical properties using optical microanalysis, scanning electron microscope, Fourier transform infrared spectroscopy, thermal gravimetric analysis and depth-sensing indentation analysis. Compared with the single-layer PU-IPDI microcapsule counterpart, the mechanical performance, thermal resistance, aging property and environmental stability of double-layer PF/PU-IPDI microcapsules were significantly improved. The epoxy coating was enhanced with the incorporation of 10 wt.% PF/PU-IPDI microcapsules, whose self-healing performance was evaluated by scratch corrosion test. The results demonstrated successful repair of coating scratches, along with the absence of corrosion on the coated steel substrate soaked in a 10 wt.% NaCl solution for 7 days. By comparing the tensile strength of epoxy coating before and after crack formation, it could be found that the self-healing efficiency was 57.9% when loaded with 10 wt.% of PF/PU-IPDI microcapsules in coating. This study highlights that the rational design of double-layer microcapsules integrated into the epoxy coating matrix could provide excellent anti-corrosion and self-healing properties. [ABSTRACT FROM AUTHOR]

Thorium biosorption by a green microalga, Chlorella Vulgaris, was studied in a stirred batch reactor to investigate the effect of initial solution pH, metal ion concentration, biomass dosage, contact time, kinetics, equilibrium and thermodynamics of uptake. The green microalgae showed the highest Th adsorption capacity at 45 °C for the solution with a thorium concentration of 350 mg L−1 and initial pH of 4. The amount of uptake raised from 84 to 104 mg g−1 as the temperature increased from 15 to 45 °C for an initial metal concentration of 75 mg L−1 at pH 4. Transformation Infrared Spectroscopy (FTIR) was employed to characterize the vibrational frequency changes for peaks related to surface functional groups. Also, the scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDX) were used to determine the morphological changes and elemental analysis of the biosorbent before and after the sorption process. The Langmuir isotherm was in perfect agreement with the equilibrium empirical data of thorium biosorption and the highest sorption capacity of the Chlorella Vulgaris microalgae was determined as 185.19 mg g−1. Also, the results of kinetic studies show that the thorium biosorption process follows a pseudo-second-order kinetic model. The negative value of ΔG0 indicates spontaneity and the positive values of ΔH0 indicate the endothermic nature of the adsorption process. [ABSTRACT FROM AUTHOR]

Reactor pressure vessel (RPV) studs are key components of nuclear reactors, and their connection with flange ensures the sealing of the RPV under high-pressure and high-temperature conditions. In the present work, the external threads of the RPV stud were prepared by triaxial rolling, and the texture evolution of the external thread root material of an RPV stud was predicted by finite element analysis coupled with viscoplastic self-consistent simulations. The microstructure of the external thread root material of RPV stud was characterized by scanning electron microscope and electron back-scattered diffraction. The installation characteristics of the turned and rolled parts of the RPV stud were tested by installation and pretightening tests. It was found that the dynamic recrystallization at the external thread root formed ultrafine tempered sorbite grains, high-angle grain boundaries (47%), and strong {111} <110> and {111} <112> textures. In the installation and pretightening test, the residual elongation of rolled parts was reduced by 6% under the same loading pressure. The triaxial rolling process distributed the microstructure of the external thread root of the RPV stud in a gradient manner, resulting in improved stud installation characteristics. [ABSTRACT FROM AUTHOR]

Two types of cells targeting Peptides, TAMS-1 (CSPGAKVRCY {Lys (Biotin)}) and MDSC-peptide (Biotin {PEG4}-MEWSLEKGYTIK), were synthesized for targeting CD206 M2 macrophage and myeloid-derived suppressor cells (MDSC), respectively. Each peptide was coaxially electro sprayed where PCL (Polycaprolactone) is the core, and the peptide is the sheath to create a PCL nanoparticle with peptides. Electro spraying parameters included applying a voltage of 44 kV, humidity between 35–44%, tip to collector distance at 160 mm, core flow rate of 0.5 ml/hr, and a sheath flow rate of 0.7 ml/hr. UV–VIS (Ultraviolet–Visible) spectrometry, SEM (Scanning Electron Microscopy) imaging, and in vivo biodistribution techniques were used to study the morphology and performance of the PCL-peptide nanoparticles. Peak absorbance values for PCL were found at around 275 nm. Peptides absorbance value was observed between 230 and 250 nm. Scanning Electron Microscope image shows nanoparticles as small as 100 nm and agglomerates as large as 1 µm. In-vivo biodistribution of PCL and CD206 M2 macrophage targeting peptide (TAMS-1) nanoparticles after intravenous injection in the tumor mice model showed uptake to the tumors. On the other hand, MDSC peptide did not show any uptake to the site of tumors. Most activity is shown in the intestine indicating excretion of the agents through the hepato-biliary system. [ABSTRACT FROM AUTHOR]

Organic dyestuff are mostly toxic compounds that pose serious dangers to the environment. Adsorption using low-cost adsorbents is the most favorable method for its economic aspects. Recently, geopolymers have been introduced as an effective adsorbent for dyes and heavy metals. In this investigation, the synthesis of geopolymers from fired brick waste (Homra) was studied with full characterization using X-ray Diffraction, Fourier Transform Infrared Spectroscopy, Brunauer–Emmett–Teller, Energy dispersive X-ray, Scanning electron microscope tests and Transmission electron microscopy. The synthesized nano-Homra geopolymer (NHGP) was then subjected to the removal of one of the most used basic dyes, Methylene Blue (MB). Adsorption optimization was applied using Response surface methodology to study dye adsorption by the synthesized nano-geopolymer. The independent variables studied were: temperature, contact time, and concentration of dye in the elimination process, which were varied in the range of (25–60 ℃), (10–180 min), and (20–300 mg/L) respectively. The results obtained from ANOVA indicated that the maximum removal efficiency of 95% and adsorption capacity of 80.65 mg/g at a temperature of 59 ℃, contact time of 163 min, and an initial concentration of 254 mg/L. The results showed that the data obtained from the adsorption of MB onto NHGP was compatible with the Pseudo second order (R2 = 0.9838) and Langmuir isotherm model (R2 = 0.9882). [ABSTRACT FROM AUTHOR]

Fucosterols have been widely studied for their antioxidant, anticancer, and anti-inflammatory properties. However, they have not yet been studied in the field of dentistry. This study aimed to determine whether pretreatment of dentin with fucosterol before resin restoration enhances bond stability in resin-dentin hybrid layers. After applying 0.1, 0.5, and 1.0 wt% fucosterol to demineralized dentin, microtensile bond strength (MTBS) and nanoleakage tests were performed before and after collagenase aging, and the surface was observed using scanning electron microscope (SEM). The fucosterol-treated group showed better bond strength and less nanoleakage both before and after collagenase aging, and the corresponding structures were confirmed using SEM. MMP zymography confirmed that the activity of MMPs was relatively low along the concentration gradient of fucosterol, and the FTIR analysis confirmed the production of collagen crosslinks. In addition, fucosterol exhibits cytotoxicity against Streptococcus mutans, the main cause of dental decay. The results of this study suggest that fucosterol pretreatment improves bond strength and reduces nanoleakage at the resin-dentin interface, possibly through a mechanism involving collagen cross-link formation via the inhibition of endogenous and exogenous MMP activity. This study demonstrates the potential of fucosterol as an MMP inhibitor in dentin, which contributes to long-term resin-dentin bond stability and can be used as a restorative material. [ABSTRACT FROM AUTHOR]

The detailed study on impact of Yb3+ on spectroscopic and 1.54 μm broadband emission of Er3+ doped transparent oxyfluroborosilicate glass ceramics (GCs) with embedded CaF2 nanoparticles was presented. The studied GCs were prepared by controlled crystal nucleation and growth process at 450 °C/1 h. Thermogravimetry and differential scanning calorimetry results showed good thermal stability and fiber drawing capacity. The scanning electron microscope and transmission electron microscope studies confirmed the formation and the uniform distribution of CaF2 nanoparticles. Various radiative and laser characteristic features were calculated within the frame work of Judd–Ofelt theory. The NIR emission at 980 nm pumping showed an intense and broad emission band due to Er3+:4I13/2 → 4I15/2 transition. The emission spectra showed a quenching in luminescence beyond 3 mol% of Yb3+ doping confirming the optimized Er3+ and Yb3+ ratio as 1:3 for enhanced emission. The stimulated emission cross-sections and quantum efficiency decrease with increased Yb3+ doping due to concentration quenching and cross-relaxation transfer of energy among Er3+ and Yb3+ ions. The experimental investigations suggest that the BSEr1Yb3GC has higher proficiency for 1.54 μm broadband fiber lasers and optical amplifiers in S and C band communication windows. [ABSTRACT FROM AUTHOR]

In the current work, phytosynthesized Copper oxide nanoparticles (CuO-NPs) were obtained in facile and sustainable way utilizing leaves of Ocimum sanctum, to detect heavy metals from surface water. The presence of phytochemicals in the green extract helps in stabilizing the nanoparticle by reducing metallic Cu2+ to CuO-NPs. Further standard physical techniques like XRD (X-ray diffraction), FTIR (Fourier transform infrared spectroscopy), UV-Vis spectroscopy and FESEM (Field-Emission Scanning Electron Microscope) confirmed the formation of CuO-NPs. The phytosynthesized CuO-NPs revealed spherical conformation with 40 nm average crystallite size, calculated by Scherrer's formula. A linear colorimetric behaviour of CuO-NPs was observed in the range of (10–400 nM) Pb2+ ions and the R2 value of 0.992 with limit of detection of 60 nM was observed. The UV-Vis spectroscopy results confirmed pronounced sensitivity and selectivity for Pb2+ ions among all the metals tested (Ba2+, Ca2+, Hg2+, K+, Mg2+, Na+, Ni2+ and Zn2+). Interference tests indicated no interference on adsorption of Pb2+ ions from aqueous solutions from other metal ions tested. Kinetic studies on Pb2+ adsorption by CuO-NPs revealed best fit to the equilibrium data of Freundlich isotherm. Besides, Pseudo 2nd order kinetics was observed to be much appropriate with R2 (linear regression coefficient) equal to 0.999 for the adsorption process. Thus, in this study phytosynthesized CuO-NPs could be a promising candidate for effective detection and elimination of Pb2+ ions from surface water making it potable. [ABSTRACT FROM AUTHOR]

This study explored thermal behavior of four kinds of chromium compounds such as CrO3, K2Cr2O7, K2CrO4, and Cr2O3 using thermogravimetry (TG) and differential scanning calorimetry (DSC) method under the oxygen (O2) and nitrogen (N2) gas atmosphere at varying temperatures (25 to 1600 ℃). A diverse of chromium compounds were carefully evaluated for the first time through this method, and the present work provides new, comprehensive and valuable information regarding the mentioned compounds. XRD technique and elemental analysis were applied in order to recognize the products at diverse decomposition stages. The obtained products were then investigated via a SEM electron microscope. Also, the form and the size of crystals were explored. Interestingly, the results obtained from both TG and DSC experiments in O2 and N2 atmospheres were identical. The thermodynamic data obtained from DSC experiments are reported in this work. Along with ∆H for each peak. It was shown that the decomposition product of K2Cr2O7 was also a mixture of Cr2O3 and K2CrO4 at 1400 °C. This study explored thermal behavior of four kinds of chromium compounds such as CrO3, K2Cr2O7, K2CrO4, and Cr2O3 using thermogravimetry (TG) and differential scanning calorimetry (DSC) method under the oxygen (O2) and nitrogen (N2) gas atmosphere at varying temperatures (25 to 1600 ℃). A diverse of chromium compounds were carefully evaluated for the first time through this method, and the present work provides new, comprehensive and valuable information regarding the mentioned compounds. XRD technique and elemental analysis were applied in order to recognize the products at diverse decomposition stages. The obtained products were then investigated via a SEM electron microscope. Also, the form and the size of crystals were explored. Interestingly, the results obtained from both TG and DSC experiments in O2 and N2 atmospheres were identical. The thermodynamic data obtained from DSC experiments are reported in this work. Along with ∆H for each peak. It was shown that the decomposition product of K2Cr2O7 was also a mixture of Cr2O3 and K2CrO4 at 1400 °C. [ABSTRACT FROM AUTHOR]

Three-dimensional printing (3DP) technology has shown great potential in rock mechanics and mining engineering due to its ability to create complex and customized objects with high precision and accuracy. At present, an emerging research focus is improving the mechanical properties of 3D-printed samples, which originally has low strength and stiffness, to match those of natural rocks. The objective of this study was to investigate the effectiveness of different post-treatments on the strength enhancement of 3D-printed gypsum samples. To achieve this goal, 3D-printed gypsum samples were subjected to different post-treatments including dipped infiltration treatment and vacuum infiltration treatment using different infiltrants: water, saltwater, ColorBond, and StrengthMax. Subsequently, each sample was subjected to ultrasonic wave velocity testing and uniaxial compression experiments to characterize their mechanical properties, CT scans to investigate their microstructural characteristics. Additionally, X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM) tests were conducted to explore the underlying reasons for changes in macroscopic strength. Finally, the physical characteristics and mechanical properties of untreated and post-processed 3D-printed gypsum samples were compared with natural rocks. The results showed that the strength of samples treated with water and saltwater was much lower than that of those treated with ColorBond and StrengthMax, while the porosity was the opposite. In water-treated and saltwater-treated samples, water or saltwater treatment can alter particle characteristics, but weak adhesive bonding and numerous pores result in low mechanical strength. Samples treated with Colorbond or StrengthMax exhibit improved strength due to effective gap filling and cohesive structure formation, with StrengthMax-treated samples showing higher strength despite having more pores than Colorbond-treated ones. Moreover, the physical and mechanical properties of these treated samples matched a wider range of natural rock types compared to the untreated samples. Highlights: This study investigates the impact of different post-treatments and infiltrants on the physical and mechanical properties of 3D-printed gypsum samples. A novel method is proposed in this study to quantitatively evaluate the degree of infiltration by comparing the changes in porosity before and after vacuum infiltration of 3D-printed samples based on 2D CT images. The study provides an in-depth analysis of the mechanisms responsible for the macroscopic strength enhancement in 3D-printed samples after vacuum infiltration treatment. Vacuum infiltration treatment using StrengthMax significantly improves the physical and mechanical properties of 3D-printed gypsum rocks, allowing them to replicate a wider variety of natural rocks compared to untreated samples. [ABSTRACT FROM AUTHOR]

Direct explosion welding makes it challenging to weld high-strength metals. Interlayer explosive welding was utilized to join the high-strength, low-melting-point aluminum alloy A7075 with the high-strength titanium alloy Ti–6Al–4 V. This method overcomes the challenges of directly welding such metals and widens the range of weldable parameters, thus facilitating more favorable welding conditions. The study effectively demonstrated the interlayer explosive welding process for A7075 with Ti–6Al–4 V using aluminum and copper interlayers. Microstructure and chemical content analysis of the bonded interfaces were conducted through optical microscope, scanning electron microscope, electron backscatter diffraction, and X-ray energy spectroscopy. The investigations found that the upper interfaces were flat and straight in shape, but the lower interfaces were wavy. Interdiffusion of components and compound formation occurred at the welded interface. In addition, grain refining took place at the bonding interface. Vickers hardness was used to measure hardness variations at the welded interface, and the mechanical properties of the bonded interface were examined using tensile shear, bending, and microtensile tests. The results confirm the practicality of interlayer explosive welding in producing high-strength, low-melting-point composites of A7075 and Ti–6Al–4 V. Microstructure analysis and mechanical testing at the weld interfaces of A7075/A1060/Ti–6Al–4 V and A7075/Cu/Ti–6Al–4 V composite plates revealed excellent bonding quality. Notably, compared to A7075/A1060/Ti–6Al–4 V composite plate, A7075/Cu/Ti–6Al–4 V composite plate performs better in mechanical tests, with tensile bending strengths of 137 MPa and 1321 MPa, respectively. Thinner interfacial melting zones were evident in the microstructure of the composite plate with a copper interlayer at the 30 mm explosive thickness parameter, correlating with improved performance in the microtensile test. [ABSTRACT FROM AUTHOR]

Single step surfactant assisted sol–gel technique was adapted to synthesize mesoporous tungstated zirconia (m-WZ). Amorphous WZs, with high surface area, were synthesized after calcination of as-synthesized materials at 550 °C for 6 h. These materials were well characterized by powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. Textural properties were established from N2 adsorption–desorption isotherm, Scanning electron microscope (SEM) and Transmission electron microscopy (TEM). Pyridine adsorbed FTIR and NH3-TPD revealed reasonable amount of Brønsted and Lewis acid sites of m-WZs. m-WZs exhibited outstanding catalytic activities toward solvent free Knoevenagel condensation reaction of different aromatic aldehydes with malononitrile and ethyl cyanoacetate at room temperature. The developed catalysts were also employed to synthesize different industrially important fine chemicals. These catalysts had longer reusability and no visible drops were observed in catalytic activity even after several runs. [ABSTRACT FROM AUTHOR]

This paper presents an experimental study that investigates the effect of fiber dimension on preventing spalling of ultra-high-performance concrete (UHPC). UHPCs with different dimensions of polypropylene (PP) fibers were prepared for permeability test at different temperatures and spalling test under ISO834 fire curve. Scanning electron microscope (SEM) observation was also conducted focusing on the fiber of a UHPC sample at the same location after it was subjected to elevated temperatures. The results of permeability tests and spalling tests showed that longer fibers of 12 mm and 18 mm and finer fibers of 28 μm and 33 μm were more beneficial for increasing the permeability of UHPC at high temperature, resulting in higher effectiveness on spalling prevention. Permeability measurements indicated a significant increase occurred at 150°C regardless of fiber dimensions; this increase plays an important role in spalling prevention. SEM results further testify that this increase can be attributed to the formation of microcracks caused by expansion of PP fibers. An aspect ratio of 300 is recommend for spalling prevention of UHPC, when 3 kg/m3 of PP fibers are used. [ABSTRACT FROM AUTHOR]

In this study, the polygonal structure of WO3 nanoparticles was constructed by the hydrothermal route, and the prepared materials were utilized for supercapacitor applications. The synthetic materials are WO3 nanoparticles in their monoclinic phase, according to the X-ray diffraction data. The morphologies of the WO3 samples are polygonal like and scanning electron microscope and transmission electron microscopy have confirmed it. To investigate the supercapacitance behavior of polygonal WO3, various techniques were used, such as galvanostatic charge–discharge, cyclic voltammetry, and electrochemical impedance spectroscopy (EIS). The polygonal WO3 nanoparticle modified on Ni-foam as a working electrode has a specific capacitance value of 870 F g−1 at 0.25 A g−1. The polygonal structure of WO3 nanoparticle-coated Ni-foam electrodes was very stable compared to other fabricated electrodes over the 10,000 cycles. The fabricated polygonal structure of the WO3 electrode has high capacitance retention (100.2%) and high coulombic efficiency (99%). The polygonal structure of WO3 makes it a particularly effective electrode material and a substantially better candidate for energy storage, especially supercapacitors. [ABSTRACT FROM AUTHOR]

Objective: this study aimed to digitally compare wear behavior and retention between PEEK and nylon retentive inserts used in locator-retained, mandibular implant overdentures when attachment design and size were standardized. Materials and methods: A total of sixty-four inserts (32 PEEK and 32 nylon inserts); were picked-up in implant overdentures. Overdentures of both groups were submerged in artificial saliva and mounted to chewing simulator. After 480,000 chewing cycles (equivalent to 2 years of clinical use) all inserts were scanned by scanning electron microscope (SEM), then all acquired images were digitally analyzed by software to detect and compare quantitative and qualitative changes of inserts in both groups. On the other hand, retention of both groups was measured by universal testing machine and the collected data was statistically analyzed using one-way Analysis of Variance (ANOVA) test with significance level set at P ≤ 0.05. Results: PEEK inserts showed significantly higher mean retentive values compared to the nylon inserts in the control group. Also, PEEK retentive inserts exhibited statistically lower mean wear values than the control group P ≥ 0.000. Qualitative investigation revealed significant and more pronounced changes in the surface roughness of nylon inserts compared to PEEK ones. Conclusions: Regarding retention, wear behavior and dimension stability, PEEK can be recommended as retentive insert material in cases of locator-retained mandibular implant overdentures. Clinical relevance: PEEK inserts offer enhanced retention, reduced wear, and greater dimensional stability over two years time interval. Clinically, this reduces prosthodontic maintenance and adjustments, improving patient satisfaction and long-term prosthetic success. [ABSTRACT FROM AUTHOR]

Magnesium dichloride (MgCl2)-supported titanium catalyst with diisobutyl phthalate (DIBP) and 3,5-di-isopropyl 1,2-phenylene diethyl dicarbonate (CD1, non-phthalate) internal donor was synthesized using magnesium alkoxide precursor. Additionally, a catalyst without the internal donor was prepared for comparative analysis. The synthesized catalysts were characterized and compared with respect to composition, surface area, particle size and morphology. The effect of CD1-based magnesium dichloride-supported Z–N catalyst was investigated for propylene polymerization and compared with DIBP-based and without internal donor Z–N catalyst system. The catalyst system with the CD1 internal donor demonstrated a higher MFI in the resultant polypropylene, suggesting a superior hydrogen response during propylene polymerization compared to both the DIBP-based and the donor-free catalyst systems. The molecular weight of the polymer was studied through gel permeable chromatography and compared for all catalyst system. The scanning electron microscope image of the polymer resin indicates spherical morphology and exact replication of catalyst. Catalyst systems exhibiting such elevated hydrogen responses hold significant industrial relevance, especially demand of high MFI PP grades in the automotive industry. [ABSTRACT FROM AUTHOR]

We present the band gap engineering and morphological tuning of BaAl2O4:0.1% Sm3+, x% Tb3+ nanophosphors synthesized by citrate sol–gel method. Herein, the samarium (Sm3+) concentration is kept constant at 0.1%, while the concentration of terbium (Tb3+) is tuned from 0.5 to 2.5% with steps of 0.5%. X-ray diffraction confirms the hexagonal crystal structure of the BaAl2O4:0.1% Sm3+, x% Tb3+ nanophosphors. The reduction in crystallite size from 38 to 31 nm is noticed after doping and co-doping. Scanning electron microscope micrographs display evolution in morphology from multimodal grain-like structures to agglomerated pointy nanorods. Energy dispersive X-ray spectroscopy confirms all the main elements, although Sm is not detected due to the low content incorporated into the lattice. Transmission electron microscope results reveal that the particle size and shape can be controlled by varying concentrations of Tb3+. Diffuse reflectance spectra with the aid of the Kubelka–Munk function, reveal the energy band gap in the range of 2.6–5.3 eV. Under the excitation wavelength of 235 nm, photoluminescence studies reveal eight emission peaks located between 380 and 641 nm characteristic of Tb3+ ions. Upon the excitation wavelength of 402 nm, the emission spectra show four peaks positioned at 564, 601, 648 and 708 nm attributed to 4G5/2 → 6H5/2, 4G5/2 → 6H7/2,4G5/2 → 6H9/2 and 4G5/2 → 6H11/2 transitions of Sm3+ ions, respectively. From the colour coordinate results, this nanophosphor can successfully play a significant role in green, yellow and red LED applications. [ABSTRACT FROM AUTHOR]

The work presents the high-temperature wettability researches carried out during glass-metal sealing for high-alumina glass and 304 stainless steel. And we explore the factors of holding time, temperature, roughness and oxide layer on wettability. The droplet diameter was measured by microscope after wetting and calculated the wetting angle. In order to analyze the elemental composition, chemical composition and microstructure of wetting interface, revealing relationship between contact angle and wetting interface, we explore it with the help of scanning electron microscope and x-ray energy spectrum. The experimental results show that the contact angle between glass and stainless steel decreases with an increase in temperature. It appears a decrease in wetting angle with temperature increasing from 1000 to 1090 °C. When the holding time is extended from 10 to 40 min, the corresponding wetting angle gradually decreases, and the wetting process approaches equilibrium finally. Moreover, the halo around the glass keeps getting bigger. The effect of stainless steel surface roughness on wettability angle has no obvious law. The glass has better wettability on the oxidized surface of stainless steel after pre-oxidation and laser surface melting. Therefore, in order to enhance the wettability of glass and stainless steel, we properly increase the heat preservation temperature and time. Besides, surface oxide layer of stainless steel can also improve the wettability. [ABSTRACT FROM AUTHOR]

Laser shock peening (LSP) is a novel non-contact surface modification technique to enhance the corrosion and compression behavior of stainless steel 308L (SS308L) material for a cryogenic application. SS308L is commonly used as a weld filler, weld electrode and cryogenic environment due to its low carbon content and good mechanical and high corrosion resistance properties. In this present study, wire-arc additive manufacturing (WAAM) has been utilized to manufactured SS308L material and studied the compression, corrosion, wettability and surface properties of the material. Further, the nanosecond laser shock peening has been utilized to modify the additive-manufactured SS308L surface and mechanical properties. From the experimental results, it has been observed that the uni-directional flow path (UDFP) deposition has better corrosion resistance wettability and surface finish than the bi-directional flow path (BDFP) deposition on wire-arc additive-manufactured SS308L material due to its more uniform microstructure and smoother surface finish. In addition, the post-processing treatment (LSP) of SS308L materials has improved the compressive strength of additive-manufactured SS308L material with 20.6 and 15.9% as compared to UDFP and BDFP due to grain surface refinement and increases in dislocation density. The corrosion rate of LSP-treated materials was reduced by 20.7% compared to the UDFP materials due to the higher corrosion potential and lower corrosion current density. The higher surface roughness has produced better passive film formation to enhanced corrosion resistance in the UDFP with LSP. Finally, the microstructure and chemical composition have been analyzed using scanning electron microscope and energy-dispersive x-ray spectroscopy. [ABSTRACT FROM AUTHOR]

The influence of pre-tensile deformation at different directions on the corrosion properties of AZ31 rolled sheet has been investigated. Uniaxial tensile test with the strain of 6% has been carried out at angles of 0°, 15°, 30°, 45°, 60°, 75° and 90° with rolling direction (RD), respectively. The corrosion behavior of specimens with different deformation directions in 3.5% NaCl solution and 8.5% Na2SO4 solution was measured by immersion test, potentiodynamic polarization method and electrochemical impedance spectroscopy. After immersion tests, the surface characteristics of various specimens were investigated by scanning electron microscope (SEM). Results showed that the tensile directions had a significant influence on the corrosion behavior. With the increase of the angle between tensile direction and RD, the hydrogen evolution rate in the 3.5% NaCl increased first and then decreased. The turning point was A45 specimen with the minimum value of 2.1 mm/y. The similar trends were also observed in the 8.5% Na2SO4 solution. In electrochemical testing, the A45 specimen exhibited the best corrosion resistance with the largest diameter of the impedance arc and lowest self-corrosion current. The further the angle of the specimen deviated from 45° direction, the lower corrosion resistance. [ABSTRACT FROM AUTHOR]

Bamboo fibres, which are widely regarded as a contemporary environmentally sustainable resource, have been utilised in various industries including construction materials and packaging sectors. Malaysia possesses a diverse array of bamboo species, rendering it a significant resource for exploration. Five out of the 69 bamboo species discovered in Malaysia were selected for their suitability and availability in the pulp and paper industry, considering properties such as high cellulose content and long fibers. The objective of this study is to conduct a comprehensive analysis of the morphological, physiochemical, thermal, and chemical properties of five specific bamboo species that are often found in Malaysia: Gigantochloa scortechinii (GS), Gigantochloa wrayi (GW), Gigantochloa levis (GL), Schizostachyum grande (SG) and Dendrocalamus asper (DA). Selected from a pool of 69 species based on their availability, these various types of bamboo were subjected to analysis using advanced scientific techniques such as Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), and X-ray Diffraction (XRD). Furthermore, a chemical composition study was performed to clarify the presence of cellulose, hemicellulose, lignin, and ash in all five species. By employing various analytical methodologies, this study investigates and records the properties offered by the bamboo species, providing a significant contribution to the comprehension and knowledge of their potential applications across diverse disciplines. This holds relevance as all five bamboo species are readily available but remain underutilized for further applications in various fields especially in packaging industries. [ABSTRACT FROM AUTHOR]

Research on the observation of nutrient release rates from slow-release and regular fertilizers combined with the percolation rate in the soil is scarce. This work aims to observe potassium and phosphate release behavior from slow-release and regular fertilizer, followed by the percolation of that nutrient in the soil. The characteristics of the soil were analyzed using X-ray Diffraction (XRD), X-ray Fluorescence (XRF), and Scanning Electron Microscope (SEM). The concentration of potassium and phosphate in soil is analyzed using Atomic Absorption Spectroscopy (AAS) and Ultraviolet–Visible Spectroscopy (UV–Vis), respectively. The release rate of nutrients from slow-release fertilizer is 6 to 8 times slower than regular fertilizer. Meanwhile, the rate of nutrients released from slow-release and regular fertilizer followed by soil percolation matches the quadratic equation. Potassium adsorption on the soil surface is significantly higher than that of potassium. The negativity of soil polarity contributed to the high level of potassium adsorption on soil particle surfaces. The low phosphate adsorption capability of magnetite and the negativity of soil polarity contributed to the soil's low phosphate adsorption. [ABSTRACT FROM AUTHOR]

Janus particles are popular in recent years due to their anisotropic physical and chemical properties. Even though there are several established synthesis methods for Janus particles, microfluidics-based methods are convenient and reliable due to low reagent consumption, monodispersity of the resultant particles and efficient control over reaction conditions. In this work a simple droplet-based microfluidic technique is utilized to synthesize magnetically anisotropic TiO2-Fe2O3 Janus microparticles. Two droplets containing reagents for Janus particle were merged by using an asymmetric device such that the resulting droplet contained the constituents within its two hemispheres distinct from each other. The synthesized Janus particles were observed under the optical microscope and the scanning electron microscope. Moreover, a detailed in vitro characterization of these particles was completed, and it was shown that these particles have a potential use for biomedical applications. [ABSTRACT FROM AUTHOR]

The effect of Ru addition on the martensitic transformation and mechanical properties of Zr50Pd50−xRux SMAs shape memory alloys has been studied. Strain–temperature experiments, differential scanning calorimeter, and scanning electron microscope analyses were performed to validate the theoretical predictions by DFT calculation regarding the influence of the C′ parameter on martensitic stability. Despite the absence of an observed shape memory effect under the tested conditions, the findings suggest that ZrPdRu alloys hold promise for high-temperature applications. [ABSTRACT FROM AUTHOR]

In this study, eco-friendly chitosan-polyvinylpyrrolidone composite (CS-PVP) was synthesized from a facile one-pot reaction at room temperature and characterized using Fourier transform Infrared (FT-IR) spectroscopy, X-ray powder diffraction (XRD), thermal gravimetric analysis (TGA), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and elemental mapping. Characterization results confirmed the successful synthesis of CS-PVP with rough surface morphology, good crystallinity and good thermal stability with the Tpeak of the first decomposition at 330 °C. Therefore, a batch experiment was carried out in order to remove eosin Y (EY) dye from the aqueous solution using CS-PVP. The effect of initial pH solution, sorbent dose and contact time on the removal efficiency of EY were considered. Result predicted that the adsorption capacity increased with the solution pH decreased from 5 to 3. The maximum adsorption capacity was 77.24 mg/g (98%) at pH solution of 3, adsorbent dose of 0.02 g and 180 min contact time. In addition, the adsorption process of EY was well fitted by the pseudo-first order (PFO) kinetic model and the Freundlich isotherm. The adsorption mechanism of EY using CS-PVP composite can be attributed to the different electrostatic attractions, hydrogen bonding and n–π interaction. The desorption studies of EY dye from the surface of PVP-CS showed that it is reusable. The thermodynamic parameters for adsorption of EY using CS-PVP were calculated and results confirmed that the adsorption is endothermic and spontaneous. This process is simple, low-cost and high effective in organic dye remove using the as-prepared CS-PVP composites. [ABSTRACT FROM AUTHOR]

Cuticle quality can affect food safety by protecting poultry eggs from bacterial infection in the modern poultry industry. However, genetic factors related to cuticle nanostructure are not much reported due to limited bird models. In the current study, the genome-edited quail targeting myostatin (MSTN) gene was used to investigate the effect of MSTN mutation on the cuticle nanostructure and quality. To analyze nanostructure of the cuticle layer of the MSTN mutant and wild-type (WT) quail eggs, scanning electron microscope (SEM) images was taken. Thickness of the cuticle layer did not differ between the MSTN mutant and WT groups, but the size of the nanospheres in the surface of the cuticle layer was increased by MSTN mutation. In addition, increased size of the nanospheres in the MSTN mutant group was also shown in the upper region of the cross-sectional cuticle layer. Notably, both groups showed similar small-sized nanospheres in the lower region of the cuticle layer and the size was increased as they ascended to the upper region. The data suggested that MSTN mutation increased the size of the nanosphere in the upper region of the cuticle layer at a late phase rather than increasing the size of nanospheres in the lower region of the cuticle layer at an early phase of cuticle formation. However, the number of Escherichia coli attached to the surface did not differ between the two groups indicating no association between nanosphere size and bacterial attachment in quail eggs. The current study demonstrated a new function of the MSTN gene on regulation of cuticle nanostructure, for the first time. These results advanced our knowledge on the association between genetic factors and cuticle nanostructure and can be served as a reference to study the mechanism of cuticle formation in the future study. [ABSTRACT FROM AUTHOR]

In the current study, silver nanoparticles (AgNPs) incorporated Polyamide 66 (PA66) nanofiber mat as a photocatalyst which was prepared using electrospinning technique for degradation of methyl orange (MO). Considering the lack of reported studies on the influence of the ultrasonication on the size and stability of AgNPs, the purpose of the study was to produce a small size of AgNPs and compare it with the continuous stirring method. It is reasonable to report that the advantage of ultrasonication is to generate relatively smaller AgNPs (u-AgNPs) compared to fabrication by continuous stirring method (s-AgNPs). Helichrysum arenarium (HA) extract was used as a reducing agent as well as a capping agent in green synthesis of AgNPs. AgNPs were characterized by UV–visible spectrophotometry, Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and transmission electron microscope (TEM). PA66/u-AgNs nanofibers were then successfully electrospun and characterized by using scanning electron microscope (SEM), FT-IR, thermal gravimetric analysis (TGA), and water contact angle measurement (WCA). Fabricated PA66-based nanofiber mat with smooth surface and uniform diameters (330–340 nm) was used as a catalyst in MO degradation. PA66/u-AgNP nanofibers were also evaluated for antibacterial performance and showed significant inhibition against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa bacteria. According to these findings, it is expected that the fabricated novel PA66/u-AgNP nanofibers can be announced as a promising potent and applied to the wastewater applications. [ABSTRACT FROM AUTHOR]

A modified carbon paste sensor based on N,N′-(((ethane-1,2-diylbis(oxy))bis(2,1-phenylene))bis(methanylylidene))bis(pyridine-2-amine; BPA Schiff base as Cr(III) selective carrier was fabricated and studied in this work. The proposed sensor homogenization and mechanism of action was studied by infra-red (IR) and scanning electron microscope (SEM) with energy dispersive X-ray (EDX) tools. The sensor covered 1.0 × 10−7–1.0 × 10–1 mol L−1 linear range and a detection limit of 7.22 × 10–8 mol L−1 for Cr(III) with 20.17 ± 0.13 mV decade−1 Nernstian slope. 5 s was the response time of the prepared sensor and it was reproducible and stable for 3 months. The working pH range was 3.3–6.0 and it also works well to determine Cr(III) ion in presence of water miscible solvents up to 12.5% content of the methanol and 17.5% of ethanol. The electrode's selectivity was studied using separate and mixed solution methods for selectivity coefficients determination and the sensor showed good selectivity relative to a variety of metal ions (selectivity coefficients = 1.01 × 10−5–8.57 × 10−3). In addition, the practical analysis value of the sensor was demonstrated by measurement of Cr(III) quantitatively in mineral water, supplement and also as an indicator electrode in Cr(III) against EDTA potentiometric titration with good reproducibility (RSDs of 0.91–2.15%). [ABSTRACT FROM AUTHOR]

This study aims to use beeswax, a readily available and cost-effective organic material, as a novel phase change material (PCM) within blends of low-density polyethylene (LDPE) and styrene-b-(ethylene-co-butylene)-b-styrene (SEBS). LDPE and SEBS act as support materials to prevent beeswax leakage. The physicochemical properties of new blended phase change materials (B-PCM) were determined using an X-ray diffractometer and an infrared spectrometer, confirming the absence of a chemical reaction within the materials. A scanning electron microscope was used for microstructural analysis, indicating that the interconnection of the structure allowed better thermal conductivity. Thermal gravimetric analysis revealed enhanced thermal stability for the B-PCM when combined with SEBS, especially within its operating temperature range. Analysis of phase change temperature and latent heat with differential scanning calorimetry showed no major difference in the melting point of the various PCM blends created. During the melting/solidification process, the B-PCMs possess excellent performance as characterized by W70/P30 (112.45 J.g−1) > W70/P20/S10 (94.28 J.g−1) > W70/P10/S20 (96.21 J.g−1) of latent heat storage. Additionally, the blends tend to reduce supercooling compared to pure beeswax. During heating and cooling cycles, the B-PCM exhibited minimal leakage and degradation, especially in blends containing SEBS. In comparison to the rapid temperature drop observed during the cooling process of W70/P30, the temperature decline of W70/P30 was slower and longer, as demonstrated by infrared thermography. The addition of LDPE to the PCM reduced melting time, indicating an improvement in the thermal energy storage reaction time to the demand. According to the obtained findings, increasing the SEBS concentration in the composite increased the thermal stability of the resulting PCM blends significantly. Despite the challenges mentioned earlier, SEBS proved to be an effective encapsulating material for beeswax, whereas LDPE served well as a supporting material. Leak tests were performed to find the ideal mass ratio, and weight loss was analyzed after multiple cycles of cooling and heating at 70 °C. The morphology, thermal characteristics, and chemical composition of the beeswax/LDPE/SEBS composite were all examined. Beeswax proves to be a highly effective phase change material for storing thermal energy within LDPE/SEBS blends. [ABSTRACT FROM AUTHOR]

The self-supported Co–Fe LDH@Ni(OH)2 material is successfully prepared on a foam nickel substrate through two hydrothermal processes. The phase structure and microstructure of the electrode material are investigated through X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), and transmission electron microscope (TEM) analyses. The electrode materials undergo electrochemical and electrocatalytic tests using an electrochemical workstation. This study demonstrates that the specific capacitance of the Co–Fe LDH@Ni(OH)2 is 2626 mF cm−2 at 1 mA cm−2. Supercapacitors made of LDH@Ni(OH)2 electrode material operate exceptionally well. Both the power density and the energy density are 0.755 mW cm−2 and 32.5 μWh cm−2, respectively. As a catalyst material for electrochemical splitting of water, CoFe-LDH@Ni(OH)2 exhibits distinguished electrocatalytic properties. The overpotential is 242 mV at 50 mA cm−2 in HER, while that is 149 mV at 20 mA cm−2 in OER. Meanwhile, the CoFe-LDH@Ni(OH)2 electrocatalytic material also performs extremely well in the overall water electrolysis testing. The voltage is 1.65 V at 25 mA cm−2, which shows strong cyclic stability. The material provides a reliable guarantee for sustained and stable operation in various application scenarios. [ABSTRACT FROM AUTHOR]

Molybdenum disulfide(MoS2) has a special structure and excellent mechanical properties, making it a promising reinforcing filler for polymers. Carbon dots (CDs) have good antioxidant properties, and the addition of CDs during the synthesis of MoS2 can affect its morphology and size. In this work, a new one-step hydrothermal synthesis process was employed to prepare CDs/MoS2 hybrid particles. Thiourea, sodium molybdate, and glucose were employed as sources of sulfur, molybdenum, and carbon, respectively. The structure and morphology of MoS2 and CDs/MoS2 were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), mapping surface scanning (SEM–EDS), and Fourier transform infrared spectroscopy (FTIR). The results show that the prepared 2H-MoS2 is stacked into flower-like spheres with size around 2–10 μm; with the formation of CDs, the size of MoS2 rapidly decreases to less than 1 μm and the CDs are evenly distributed on its surface with mass ratio of 40.2% (CDs in CDs/MoS2). Subsequently, the CDs/MoS2 were used as reinforcing fillers for natural rubber (NR) latex. The results of mechanical properties show that tear strength, tensile strength, modulus, and elongation at break are increased by the addition of CDs/MoS2 in a very lower loading, and the maximum increment ratio is 45.6% and 12.1% when compared to NR-0; the dynamic mechanical analysis and cross-link density results indicated that the CDs/MoS2 can simultaneously improve rigidity and elasticity of NR. The thermal stability results suggest that the CDs/MoS2 shows positive effects on thermal stability of NR. [ABSTRACT FROM AUTHOR]

Background: In this research, a brewer's yeast suspension was used to biotreat raw linen fibers under a range of different circumstances utilizing an ultrasonic cleaner device. In order to optimize circumstances for the treatment process, this extensive work is focused on examining the variables that could affect the biotreatment, such as the amount of brewer's yeast used, the duration, the temperature of the treatment, and the pH throughout the treatment. After enzymatic treatment, the printing process utilizing turmeric natural dye was used. Variable assesses were conducted to determine the steaming time, thermofixation time, pH of the printing paste, types of dyes, and types of fabrics. How these elements affected the wettability and fabric color strength is investigated. To better comprehend, scanning electron microscope (SEM) was used to study the morphology of treated and untreated linen samples. The effects of treating the fibers with yeast enzyme on their multifunctional qualities, such as color and antibacterial activity against gram-positive bacteria like Staphylococcusaureus and gram-negative bacteria like Escherichia coli, were assessed. Results: Results demonstrated that the enzyme extract, which predominantly contains lipase, amylase, and protease enzymes that develop the fabric printability, is responsible for the increase of color strength which increased by about 152.27% with good fastness properties compared by the untreated printed samples. Conclusions: The overall findings showed that the treated fabrics have superior color fastness and antibacterial properties when compared to the untreated fabrics, demonstrating that the procedure of production used to create these multifunctional linen fabrics is environmentally friendly. [ABSTRACT FROM AUTHOR]

Tungsten argon arc welding (TIG), cold metal transfer (CMT) welding and flash butt welding (FBW) are used to join M390 and 304. The mechanical properties of M390 and 304 welded joints with different welding methods were compared by tensile and microhardness experiments. The microstructure evolution and phase changes of TIG, CMT and FBW welded joints were compared and analyzed by scanning electron microscope (SEM) and x-ray diffraction. The grain size of weld metal (WM) and M390 heat-affected zone of three types of welded joints were measured by Image J software. Corrosion resistance of three types of weld joints was characterized by electrochemical corrosion tests, and the microstructure of post-corrosion test specimens was characterized by SEM and EDS. The results show that three types of welded joints without cracks and voids can be obtained between dissimilar metals M390 and 304. The microstructure of TIG weld metal is composed of martensite and the carbides M7C3 and M23C6 due to higher heat input during TIG welding processes. Because extensive C, Cr and Ni element diffusion occurs during FBW welding due to low heat input, the microstructure of the weld metal is composed of martensite and austenite matrix and carbides of M7C3 and M23C6. The filling of nickel-based alloys during CMT welding processes make the microstructure include austenite and (Al, Ni, Ti) carbide. The tensile strength and elongation of CMT welded joint can reach 501 MPa and 21.8%, the corrosion current density is 4 mA cm−2, and the corrosion voltage is − 21 mV, which is the best mechanical properties among the three types of welded joints. The welded joints with the three welding methods are all fractured at WM position. [ABSTRACT FROM AUTHOR]

The microstructure and mechanical properties of as-extruded Mg-8Sn-4Al alloys micro-alloyed with Ag and Sc elements were investigated by optical microscopy, x-ray diffraction, scanning electron microscope and electron backscattered diffraction. The as-cast Mg-8Sn-4Al, Mg-8Sn-4Al-0.8Sc and Mg-8Sn-4Al-1Ag-0.8Sc alloys were extruded at 320 °C with an extrusion ratio of 25 without further solid solution and aging treatment. The microstructure of all as-cast and as-extruded Mg-8Sn-4Al alloy is composed of α-Mg matrix and Mg2Sn phase. The extrusion treatment and Ag and Sc addition obviously refine the grains and Mg2Sn phase. A complete dynamic recrystallization and a slight basal texture were observed in the as-extruded alloys. In addition, the stable block-shaped Al3Sc phase was also observed in Mg-8Sn-4Al alloys with Sc addition after extrusion treatment. Interestingly, the Sc or Ag-Sc addition simultaneously improves the tensile strength and elongation of as-extruded Mg-8Sn-4Al alloy. The enhanced ultimate tensile strength and tensile elongation of as-extruded Mg-8Sn-4Al-1Ag-0.8Sc alloy reach 318.07 MPa and 14.41%, respectively, which are higher than these of as-extruded Mg-8Sn-4Al alloy. This is mainly attributed to the grain refinement, Mg2Sn phase refinement and solid solution elements (Al, Ag and Sc). The Ag and Sc addition to as-extruded Mg-8Sn-4Al alloy is positive to dynamic recrystallization and mechanical property, and corresponding mechanisms are discussed in detail. [ABSTRACT FROM AUTHOR]

Transient liquid phase (TLP) bonding of Ti-6Al-4 V/UN32750 joint with a composite interlayer of Cu-0.5 wt.% CNT and a pure Cu interlayer has been investigated. TLP process was performed in a vacuum furnace at three different temperatures (900, 950, and 1000 °C) with a constant holding time (60 min). Microstructure and mechanical properties of all joints were studied using scanning electron and optical microscopes, microhardness, and shear tests. The x-ray diffraction (XRD) test was done on all fracture surfaces to do phase analysis at the interface. Results showed that the increase in the thickness of the TLP layer is associated with CNT addition, inferring that CNT enhances the diffusion of alloying elements across the interface. All joints experienced a reduction in the strength after CNT addition, with the highest strength obtained at 950 °C. The microhardness of the CNT-containing joints is higher than that of CNT-free samples due to the formation of plate-shaped Al-based phases and solid solution strengthening. All joints showed brittle fracture features. CNTs improved the brittle fracture to some extent, especially at 1000 °C. [ABSTRACT FROM AUTHOR]

Two series based on poly(propylene 2,5-furandicarboxylate)-block-poly(tetramethylene oxide) (PPF-b-F-PTMO) containing carbon and mineral nanofillers that differ in shape (1D and 2D) were synthesized via in situ polymerization. The influence of the addition of the 1D-type nanoparticle, i.e., carbon nanofibers (CNFs) and halloysite nanotubes (HNTs), and the so-called 2D-type, i.e., graphene nanoplatelets (GNPs) and organoclay (C20A), on the properties of a biobased block copolymer was analyzed. The dispersion of nanoadditives in the nanocomposites was determined using a scanning electron microscope (SEM). The thermal properties were studied employing differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The introduction of nanoparticles increased the crystallinity (Xc) and the mean values of tensile modulus (E) of the bionanocomposites. In turn, one observed that the decrease in the limited viscosity number (LVN) was visible along with incorporating nanoadditives. The synthesized polymer bionanocomposites reveal the mechanical properties of elastomers during mechanical testing. Moreover, the good processability of the obtained materials by injection molding combined with the comprehensive ability to change mechanical and thermal properties of PPF-b-F-PTMO by tailoring the type and content of the nanofillers can indicate their possible applications in packaging, automotive, sports, construction, and many other industries. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOFs) with their exceptional properties have the potential to revolutionize the field of electrochemistry and pave the way for new and exciting applications. MOFs is an excellent choice as an active electrocatalyst component in the fabrication of electrochemical sensors. Here, bimetallic NiCo-MOFs, monometallic Ni-MOFs, and Co-MOFs were fabricated to modify the carbon paste electrode. Moreover, the ratio between Co and Ni within the bimetallic MOFs was optimized. Our aim in this work is to synthesize different compositions from bimetallic MOFs and systematically compare their catalytic activity with mono-metallic MOFs on paracetamol. The structure and properties of the 2D NiCo-MOFs were characterized by scanning electron microscope, X-ray photoelectron spectroscopy, Fourier transform infrared, and electrochemical method. Bimetallic Ni0.75Co0.25-MOFs modified carbon paste sensor displayed the optimum sensing performance for the electrochemical detection of paracetamol. A linear response over the range 6.00 × 10− 7 to 1.00 × 10− 4 M with a detection limit of 2.10 × 10− 8 M was obtained. The proposed method was applied to detect paracetamol in spiked human plasma and to determine paracetamol in the presence of its major toxic impurity, p-aminophenol. These findings suggest the considerable potential use of the newly developed sensor as a point-of-care tool for detecting paracetamol and p-aminophenol in the future. [ABSTRACT FROM AUTHOR]

Background: As a vital soil-borne pathogenic bacterium, Ralstonia solanacearum can cause wilt disease in multiple Solanaceae plants. Several phages, such as ϕPB2, could infect R. solanacearum acting as a potential biological control agent in soil. In addition, some nanoparticles, especially copper preparation, also showed high toxicity on R. solanacearum with low toxicity on plant. However, whether they can be administered in combination and how effective they are in inhibiting the plant disease caused by R. solanacearum is known very little. Results: In this work, the characterization of CuONPs using scanning electron microscope, transmission electron microscope, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction ascertained the presence of CuONPs which were nanometer particle of 83 nm. Then it was found that combined application of CuONPs with phage (ϕPB2) was superior to that of ϕPB2 or CuONPs alone in controlling tobacco bacterial wilt, with the CuONPs (250 mg/mL) and phage (106 PFU/mL) ratio being the best, at 79.1%. The combination of CuONPs and ϕPB2 also showed no obvious toxicity on tobacco growth than control like single application of CuONPs or ϕPB2. Furthermore, the transcriptome changes of R. solanacearum analysis indicated that the combination application and single allocation of CuONPs could inhibit "biofilm formation", molecular function, biological processes, cellular components, metabolic process, and so on. In addition, the combination application showed higher inhibition of motility and biofilm, and better enhancement of cell membrane permeability, protein leakage, MDA concentration, and enzyme activity of their respiratory chain dehydrogenase than single application of CuONPs or phage (ϕPB2). Transcriptomes analysis also supported that the addition of ϕPB2 enhanced the toxicity of CuONPs by influencing the ABC transporters and quorum sensing, metabolic processes, and cellular biosynthetic processes of R. solanacearum. Conclusion: In total, our work not only proposed a novel way to increase the bactericidal effect of nanomaterials by adding phage, but also discovered the influence, synergistic effects, and mechanisms, which is useful to design novel way to combat phytopathogenic bacteria in the complicated environment. [ABSTRACT FROM AUTHOR]

Dilobocondyla (Formicidae: Myrmicinae) is an uncommon and rare ant genus with only 21 species and one subspecies worldwide. The distribution of this genus is confined to the Oriental and Indo-Australian regions and reported from the Philippines, Vietnam, Indonesia, Borneo, Singapore, Malaysia, Sri Lanka, India, China, Australia and New Guinea. There is limited information about the species and some are only known from a single specimen. The characters of all the species are comprehensively compared and presented. From India, two species of Dilobocondyla, namely D. bangalorica from Karnataka and D. gasteroreticulata from Uttarakhand, Himachal Pradesh, and Sikkim have been reported. We observed D. gasteroreticulata in the campus of Gauhati University, Assam solitarily foraging on the tree trunk of Delonix regia, Mangifera indica, Monoon longifolium. Dilobocondyla may have preference for specific plants as we noticed D. gasteroreticulata on three plant species while D. bangalorica earlier reported to be present on Plumeria sp. We collected 8 specimens and identified them as D. gasteroreticulata following the taxonomic keys and morphological studies using a stereo zoom microscope and scanning electron micrographs. Assam is a part of the Eastern Himalayan biodiversity hotspot where the presence of D. gasteroreticulata is the first report from this state. The other three states where the species exist are also part of the Himalayas region. Besides, the species has recently reported from China. The geographical and climatic conditions of the regions and physiological and evolutionary adaptations of the inhabitant species influence its confined distribution which demands further investigations. [ABSTRACT FROM AUTHOR]

Diabetes mellitus (DM) is a rapidly prevailing disease throughout the world that poses boundless risk factors linked to several health problems. Vildagliptin is the standard dipeptidyl peptidase-4 (DPP-4) inhibitor type of medication that is used for the treatment of diabetes anti-hyperglycemic agent (anti-diabetic drug). The current study aimed to synthesize vildagliptin-loaded ZnO NPs for enhanced efficacy in terms of increased retention time minimizing side effects and increased hypoglycemic effects. Herein, Zinc Oxide (ZnO) nanoparticles (NPs) were constructed by precipitation method then the drug vildagliptin was loaded and drug loading efficiency was estimated by the HPLC method. X-ray diffraction analysis (XRD), UV–vis spectroscopy, FT-IR, scanning electron microscope (SEM), and EDX analysis were performed for the characterization of synthesized vildagliptin-loaded ZnO NPs. The UV–visible spectrum shows a distinct peak at 363 nm which confirms the creation of ZnO NPs and SEM showed mono-dispersed sphere-shaped NPs. EDX analysis shows the presence of desired elements along with the elemental composition. The physio-sorption studies, which used adsorption isotherms to assess adsorption capabilities, found that the Freundlich isotherm model explains the data very well and fits best. The maximum adsorption efficiency of 58.83% was obtained. Further, In vitro, anti-diabetic activity was evaluated by determining the α-amylase and DPP IV inhibition activity of the product formed. The formulation gave maximum inhibition of 82.06% and 94.73% of α-amylase and DPP IV respectively. While at 1000 µg/ml concentration with IC50 values of 24.11 μg/per ml and 42.94 μg/ml. The inhibition of α-amylase can be ascribed to the interactive effect of ZnO NPs and vildagliptin. [ABSTRACT FROM AUTHOR]

Greener fabrication of nanostructures has received remarkable attention due to their sustainability, cost-effectiveness, simplicity, and eco-friendliness. Opuntia ficus-indica-derived mucilage has not been exposed well to fabricate nanostructures. Thus, in this present investigation, we successfully synthesized tungsten trioxide (WO3) nanostructures using Opuntia ficus-indica-derived mucilage as bio-templates because it is more economical and environmentally friendly. Also, the fabricated WO3 nanostructures cytotoxic features and their photothermal effects were studied. The WO3 nanostructures were investigated using diverse analytical instruments: X-ray diffractometer (XRD), scanning electron microscope and, transmission electron microscope. Based on the structural and morphological characteristics of the WO3 nanostructures, they have sphere-like morphologies with diameters of 100 - 200 nm. As revealed by XRD, monoclinic crystalline WO3 nanostructures were formed. In vitro assays were used to assess the effect of WO3 nanostructures on cell viability and morphological features of cells. Based on in vitro assays, fabricated WO3 nanostructures showed slightly toxic behaviour in a human breast cancer cell line (MCF-7 cells). In contrast, after exposure to NIR lasers, the viability of WO3 nanostructures treated cells decreased significantly. Because the WO3 nanostructures have an excellent photothermal effect, which triggers cell death in cancer cells. Thus, the fabricated WO3 nanostructures can be used as a photothermal agent for cancer therapy [ABSTRACT FROM AUTHOR]

Flawed rocks subjected to hydrostatic confinements in deep underground engineering are vulnerable to dynamic disturbances. Understanding the dynamic mechanical responses and fracture characteristics of flawed rocks is crucial for the design and construction safety of deep underground structures. In this research, using a triaxial split Hopkinson pressure bar device, the dynamic triaxial compression tests are performed on multi-flawed sandstone specimens containing different flaw angles and distances. The experimental results revealed the influence of the flaw angle, flaw distance, and hydrostatic confining pressure on the dynamic strength characteristics, deformation properties, failure modes and fracture mechanisms of rocks. Both the dynamic strength and elastic modulus increase with rising hydrostatic confining pressure, while the dynamic strength depicts a positive correlation with strain rate. The dynamic strength fluctuates zigzag with the flaw angle, and decreases first and then increases slightly with flaw distances. Specimens with different flaw angles all demonstrate conjugated "X" shape failure, while the single shear band failure is shown for certain flaw distances. Seven crack categories are identified based on the basis of different trajectories and the fracture characteristics of new cracks are analyzed in multiscale perspective. The scanning electron microscope observation indicates numerous shear traces on the fracture surface while brittle fracture features are relatively few. Furthermore, the fracture surface roughness is quantified by the 3D scanning technique and fractal dimension. Rocks containing higher flaw distance or under higher hydrostatic confining pressure are featured by lower fractal dimension and smoother fracture surfaces. Highlights: Dynamic impacting tests on hydrostatically confined rocks containing multiple flaws were conducted. The influence of hydrostatic confining pressure and flaw configuration on the dynamic strength, deformation properties, and failure characteristics of rocks were investigated. The fracture mechanism of flawed rocks under hydrostatic confinements by the scanning electron microscope and 3D scanning technique was analyzed. [ABSTRACT FROM AUTHOR]

As a typical toxic substance in environmental water, phenolic pollutants, represented by p-nitrophenol, pose a great threat to the ecological environment. In this study, using WCl6 and oxalic acid as raw materials, a novel p-nitrophenol (PNP) sensor fabricated by tungsten phosphide (WP) nano-particles, has been successfully designed and constructed, which expanded the application of WP nano-materials in the field of electroanalysis. The successful synthesis of WP has been confirmed by a series of characterization techniques such as X-ray diffraction, scanning electron microscope, transmission electron microscope, and X-ray photoelectron spectroscopy. The electrochemical experiments were all carried out in phosphate buffer solution with the pH of 6.5. The WP nano-particles can electrocatalytically oxidize PNP to produce a current for the detection of PNP. The reaction sites of PNP are predicted by Gaussian 09 and Multiwfn. Prominent performance has been recorded for PNP sensor, attaining a wide linear range from 10.00 to 6500.00 μM, a low detection limit of 1.59 μM with the reliable selectivity, repeatability, and stability. Gratifyingly, the prepared sensor could satisfy the requirements of PNP determination in actual environmental water, such as tap water and rainwater. [ABSTRACT FROM AUTHOR]

The damage mechanisms of ductile fracture under shear loading of an aluminum alloy 2198T8R were studied using flat thin-sheet samples. One sample was loaded until 85% of the failure displacement and then unloaded, and another one was loaded up to failure. To overcome the inherent shortcomings of nanotomography concerning the investigation of flat samples, synchrotron nano-laminography was applied to the pre-loaded sample and provided structural information down to the nanometer scale, allowing ductile damage nucleation and evolution to be studied. The damage features, including flat cracks and intermetallic particle-related damage, were visualized in 3D from the highly-deformed shear band region. Using nano-laminography, no nano-voids were found. The damaged shear ligament was also observed after polishing via destructive correlative scanning electron microscope (SEM) and electron back-scatter diffraction (EBSD) which suggests that the detrimental flat cracks were both intergranular and transgranular. The flat cracks were related to highly-deformed bands. No nano-voids could be found using SEM analysis. Fractography on the second broken sample revealed that the flat cracks contained hardly observable nanometer-sized dimples. The final coalescence region was covered by sub-micrometer-sized dimples, inside which dispersoid particles were present. The fact that no nano-void was found for the pre-deformed sample implies that the nucleation, growth and coalescence of these sub-micrometer-sized voids occur at late stages of the loading history. [ABSTRACT FROM AUTHOR]

La1 –xSrxCoO3 (x = 0.1, 0.2, 0.3, 0.4, and 0.5) were prepared by the alginic acid sol–gel route and characterized by thermo gravimetric analysis (TGA), Fourier transform infrared (FT-IR), X-ray diffraction (XRD), and scanning electron microscope (SEM) techniques. The electrocatalytic activity of fabricated oxide electrodes (Ni/oxide) was studied for oxygen evolution reaction (OER) in an alkaline medium. The cyclic voltammetry of oxide electrodes shows a pair of redox couple at anodic peak potential (Epa) = 400 ± 6 mV and cathodic peak potential (Epc) = 296 ± 8 mV. The observed values of electrode kinetic parameters such as the Tafel slope (b) lie between 91 and 126 mV dec–1 and current density (j) lie between 17.0–73.1 mA cm–2 at 0.85 V. The Sr-substitution in lanthanum cobaltate matrix improve electrocatalytic activity for OER in an alkaline medium and maximum improvement was observed in the case of 0.4 mol Sr-substituted oxide. The order of reaction (p) with respect to the concentration of [OH–] is found unity and the highly negative value of entropy of the reaction indicated the oxygen evolution follows the same mechanism and involves the adsorption of the reaction intermediate. [ABSTRACT FROM AUTHOR]

In this paper, the silicone rubber (SR)/thermoplastic polyurethane (TPU) composites and its compatibilizers were studied by molecule dynamics simulation and experiment. Three compatibilizers, fluorosilicone rubber (FSR), dendritic hydroxyl-terminated silicone oil (DHSO), and fluorinated modified tetraethyl orthosilicate grafted silicone rubber (FTEOS-g-SR) were introduced into the SR/TPU composites. The simulation results showed that the cohesion density of pure SR was 3.072 × 108 J/m3, the solubility parameter was 17.504 (J/cm3)0.5, the Young's modulus was 4.0139 GPa, the shear modulus was 1.4493 GPa, and the bulk modulus was 5.8061 GPa. Moreover, the cohesion density of SR/TPU/FSR and SR/TPU/DHSO increased to 4.693 × 108 and 3.459 × 108 J/m3, solubility parameter increased to 21.662 and 18.597 (J/cm3)0.5, the Young's modulus increased to 6.6399 and 6.0020 GPa, shear modulus increased to 2.4377 and 2.2060 GPa, and bulk modulus increased to 8.0148 and 7.1653 GPa, respectively. However, the cohesion density, solubility, and young's modulus of SR/TPU/FTEOS-g-SR decreased to 2.617 × 108 J/m3, 16.174 (J/cm3)0.5, 3.872 GPa, 1.7510 Gpa, and 1.6365 GPa. These results demonstrated that both FSR and DHSO can improve the mechanical properties of the SR/TPU composites, while the FTEOS-g-SR reduced their mechanical properties. The compatibility and mechanical properties of SR/TPU composites modified by FSR and DHSO were verified and compared. The factors such as blending temperature, blending ratio, and TPU types of SR/TPU composites were considered. Compared to composites cured at 185 °C, those cured at 175 °C exhibited better mechanical properties. The dynamically vulcanized SR/TPU (3:7, mass ratio) materials showed superior tensile strength and elongation at break when compared to the SR/TPU (5:5, mass ratio) composites. Moreover, the polyether type of TPU was found to be more favorable than the polyester type for obtaining a blended composite with good tensile properties. The experimental results demonstrated that both compatibilizers contributed to improving the mechanical properties of the composites to a certain extent. The scanning electron microscope (SEM) test revealed that FSR enhanced the dispersion of SR in the TPU matrix. Additionally, charge distribution simulation analysis indicated the presence of abundant intermolecular hydrogen bonds between FSR and TPU, which played a significant role in the excellent compatibility and mechanical properties observed in this blend system. [ABSTRACT FROM AUTHOR]

The progress in developing biomaterials for cartilage replacement is still not sufficient, and researchers face the challenge of developing materials that can imitate the physical, chemical, and mechanobiological characteristics of natural cartilage. In this research, the graphene oxide was blended with polyvinyl alcohol/chitosan composite to fabricate composite hydrogels (PVA/Chitosan/GO) using different concentrations of graphene oxide (0, 0.75, 1.5, 2.25, and 3 wt%). The images taken with a scanning electron microscope (SEM) displayed that adding graphene oxide affected the hydrogel structure by reducing the porosity. The composite hydrogel with 3 wt% graphene oxide exhibited the highest compressive strength of 2.15 MPa, and the storage modulus was significantly greater than that of polyvinyl alcohol/chitosan, which satisfied the application requirements. Furthermore, the composite hydrogels displayed excellent antimicrobial activity against Escherichia coli and Staphylococcus aureus bacterial species. They exhibited in vitro cell viability against L929 mouse fibroblasts, which presents the possibility of using composite hydrogel for cartilage regeneration. [ABSTRACT FROM AUTHOR]

Here, ultrasonic spray pyrolysis method (USP) was utilized to produce pure and silver doped copper oxide nanostructures on glass substrates. Thereafter, several characterization techniques were conducted on the grown samples to delve into their morphological, structural, electrochemical, and optical aspects. The mentioned analyses were carried out by performing x-ray photoelectron spectroscopy, scanning electron microscope, X-ray diffraction, electrochemical impedance spectroscopy, galvostatic charge-discharge, cyclic voltammetry, and UV–visible spectroscopy measurements. Thus, the impact of silver impurity doping on the relevant aspects of host material were recorded as well as the features of unspoiled copper oxide films. Accordingly, the samples, as indicated by X-ray diffraction results, possessed (002) preferential plane orientation of copper oxide material along with the crystallite sizes ranging from 52.52 nm to 75.02 nm due to the imperfections caused by the silver doping. The scanning electron microscope images exhibited that the silver doping did not form significant modifications in the host material morphology where nanowire-like structures observed. The presence of the suggested materials in the films was verified by the x-ray photoelectron spectroscopy. Also, the UV–visible spectroscopy measurements detected that optical absorbance edge and bandgap energy values red shifted as a result of the impurity doping. The electrochemical supercapacitors performances of the silver doped copper oxide nanostructured thin films were inspected by using the GCD, EIS, and CV. The silver doped copper oxide films demonstrated a specific capacitance value of 66 F/g at a current density of 1 A/g in 1 M KOH electrolyte. From Nyquist plot, Rs, Rcor, Rpo, Ccor and Cc were obtained as 2.327 × 103 Ω.cm2, 43.63 × 103 Ω.cm2, 4.580 × 103 Ω.cm2, 111.5 × 10-6 S*s^a. cm-2 and 101.1 × 10-6 S*s^a. cm-2, respectively. The results indicated that the electrochemically synthesized the silver doped copper oxide electrodes can be obtained and developed as an alternative electrode material for supercapacitors (SCs). [ABSTRACT FROM AUTHOR]