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To reveal the mechanism of the influence of the curing temperature on the strength of lime activated fly ash-GGBS cured silt soil, the curing of dredged silt was carried out by using fly ash and GGBS as the curing agent and lime as the activator. Unconfined compressive strength (UCS) experiments were carried out, and the micro-analysis of the cured silt was carried out by experimental methods including scanning electron microscope (SEM) tests, X-ray diffraction (XRD), etc. to reveal the mechanism of the curing temperature on the dredged silt. According to the test results, the hydration reaction and pozzolanic reaction between lime-fly ash-GGBS and silt soil were promoted with the increase of the curing temperature. when the curing temperature of the sample reached 40 ℃, a large amount of gel products such as hydrated calcium aluminate (C–A–H) and hydrated calcium silicate (C–S–H) were generated, which enhanced the bonding force between soil particles and filled up the inter-particle pore space, thereby improving the UCS of the sample. The results of SEM confirmed that C–A–H and C–S–H were the main substances for the construction of cured silt skeleton. C–S–H and C–A–H were detected by XRD. The results of the study fill the gap in the effect of curing temperature on the direction of lime-activated fly ash-GGBS cured silt soil. [ABSTRACT FROM AUTHOR]

One of the challenges of storing hydrogen in saline aquifers is the possible geochemical reactions between host rock, formation solution, and hydrogen. This study investigated the effect of hydrogen treatment on the mechanical properties of sandstone samples from Hulett member of Sundance Formation, a potential underground hydrogen storage host in Wyoming, USA. Cylindrical specimens were treated with brine, brine+50%H 2, and brine+100%H 2 for two weeks at a pressure of 15 MPa and a temperature of 83 °C. X-ray diffraction (XRD), scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET), uniaxial compression, and triaxial compression tests were conducted on specimens. Results showed that specimens treated with brine+50%H 2 and brine+100%H 2 , on average, exhibited 24 and 41% lower peak strength, respectively, compared to that of specimens treated with the brine. XRD results showed a decrease in dolomite and clay content of specimens after exposure to hydrogen, causing degradation of the mechanical and elastic properties of the specimens. • The effect of hydrogen on the mechanical properties of Hulett sandstone was investigated. • Dolomite and clay dissolution was observed after the treatment with hydrogen. • Specimens treated with hydrogen on average showed 41% lower strength. • An average 43% decrease in elastic modulus was observed after hydrogen treatment. [ABSTRACT FROM AUTHOR]

In situ tensile testing in a scanning electron microscope was used to study the effects of fiber orientation and colony boundaries in laser-refined fully eutectic Al–Si and Al–Si–Sr alloys. In Al–Si alloy, the measured tensile stress–strain response in samples from single colonies is highly dependent on the orientation of Si nanofiber relative to the loading direction. Tensile samples with multiple colonies exhibit improved strain hardening but the measured ductility was limited by cracking along inter-eutectic colony boundaries. The Al–Si eutectic alloys, doped with Sr and processed with finer spot size laser beam, exhibit higher yield strength in samples from single colony due to refined fiber diameter and inter-fiber spacing of nanoscale Si fibers. As a consequence, samples with multiple colonies exhibit sliding or cracking at eutectic colony boundaries before significant uniform elongation developed within the colonies. The low ductility of Al–Si–Sr sample could be ascribed to the reduced shear strength of colony boundary induced by Sr element addition. [ABSTRACT FROM AUTHOR]

In this research, the main aim is to focus the enhancement of aluminium-based metal matrix composites for improving the attributes of light weight metals, aerospace structures and other tailor blank material properties. By this way, the friction stir processing (FSP) was the suited alternate technique to enhancing the mechanical attributes and superior microstructural amendment in the processed MMCs. Therefore, this study investigates the dispersion of ceramic-based strengthening particles of chromium oxide (Cr2O3) in the aluminium base matrix of A356 alloy. During the processing, the different tool pin sizes having the conical threaded tool pin profiles. Similarly, the tool spinning speed and tool travel speed also varied while in FSP. Before the processing, the A356 alloy was prepared by the grooved surfaces for packing the chromium oxide particles to compose the aluminium metal matrix composites. The tensile strength and hardness was employed to carry out from the friction stir processed A356 alloy with influencing of Cr2O3. The maximum occurred tensile processing parameters are 1500 rpm of spinning speed, 6 mm of tool pin sizes and 90 mm/min of tool travel speed. Similarly, the maximum obtained hardness processing parameter are 2000 rpm of spinning speed, 5 mm of tool pin sizes and 90 mm/min of tool travel speed. A scanning electron microscope was utilized to investigate the dispersed Cr2O3 in the A356 alloy for confirming the refinement grains in the nugget zones of FSPed A356 alloy. The increased grain boundary by the influence of different tool pin sizes was the major reason to produces the better mechanical properties in the processed A356/Cr2O3. [ABSTRACT FROM AUTHOR]

Background: Researchers, prompted by the toxicity and side effects associated with cisplatin, are exploring alternative approaches for developing transition metal-based anticancer agents. Employing a green biochemical approach, we transformed Nickel pyridine dicarboxylic acid compounds into the nanoscale using the aqueous extract of Macrotyloma uniflorum (horse gram). Results: Characterization of the biosynthesized nanoparticles involved electronic and IR spectroscopy. A scanning electron microscope revealed a predominant spherical shape for most Nickel nanoparticles (Ni-NPs), with XRD patterns indicating particle sizes ranging from approximately 30–150 nm. The nanoparticles were evaluated for their free radical scavenging efficiency and in vitro anti-malignant properties against HeLa and A549 cancer cell lines. Numerical optimization of the DPPH and MTT assays was conducted using response surface methodology (RSM), focusing on the effects of 3,4-pyridine dicarboxylic acid (ML1), 2,4-pyridine dicarboxylic acid (ML2), nickel nanoparticles concentration, and temperature. In this investigation, the incorporation of Horse Gram seed extract (Macrotyloma uniflorum) has unveiled its abundance in phenolic and flavonoid compounds, widely acknowledged for their robust antioxidant activity in the existing literature. Conclusion: The present study highlights the potential for refining the bio-toxicity and biochemical attributes of Ni-NPs to pave the way for a new generation of versatile anticancer agents with clinically established efficacy. Notably, the anticipated data closely corresponds with experimental outcomes, reinforcing the trustworthiness and validity of the RSM model for examining anticancer and antioxidant properties in this context. ML2 exhibited heightened antioxidant and anticancer activities in comparison to ML1 nanoparticles. [ABSTRACT FROM AUTHOR]

Background: The intricate textural patterns commonly observed in metamorphosed and recrystallized zircon (ZrSiO4) underscore the crucial necessity of understanding the underlying mechanisms governing their formation to ensure accurate interpretation of the chemical and isotope data they contain. This study employed a combination of microanalytical techniques, including electron backscattered diffraction (EBSD) analysis, electron microprobe (EMP) mapping, and scanning electron microscope (SEM) imaging, to investigate the processes of formation and modification of zircon in a late Pleistocene (~ 35 ka) syenite enclosed within the Nari Tephra Formation on Ulleung Island in South Korea. Findings: Under cathodoluminescence (CL), zircons within the syenite reveal dark, featureless, or oscillatory-zoned cores containing numerous inclusions of britholite. These cores are partially or entirely replaced by inward-penetrating bright-CL domains that exhibit minimal inclusion presence. Despite these changes, the external morphologies of the zircons remain largely unchanged, and the faded oscillatory zoning is preserved in the replaced regions. EMP mapping discloses amoebiform micro-domains with high Y, U, and Th concentrations within the dark-CL cores, while the bright-CL domains are relatively deficient in these trace elements. Microstructural analysis of the zircons using EBSD mapping indicates no significant misorientation between the dark-CL cores and the bright-CL rims. Deformation-related low-angle boundaries by lattice distortion are clearly observed in certain grains, cutting across the discrete SEM and EMP domains, and often aligned along submicron pore trails. Conclusions: Microstructural and microchemical analyses carried out in this study establish that the zircons within the Ulleung syenite have undergone subsolidus recrystallization, a process likely influenced by the presence of fresh melts or fluids. This recrystallization process could be attributed to either coupled dissolution and reprecipitation or thermoactivated particle and defect volume diffusion due to inherent lattice strain. The subsequent deformation observed in the zircons might be a result of increased stress within the magma system after the recrystallization. [ABSTRACT FROM AUTHOR]

The crystal morphology and conformational changes during crystallization of a polypropylene random copolymer (PPR) are the basis for understanding its crystallization process. In this work, novel rare-earth β-nucleating agent WBN-28 was directly added into PPR to induce β-crystallization. The results of differential scanning calorimetry (DSC) showed that it has an excellent β-crystal-induced effect. The β-crystal content could surpass 85%, calculated from wide-angle X-ray diffraction (WAXD) data. The morphology of the β-crystal and α-crystal was intuitively observed via a polarizing optical microscope (POM). The β-crystallites were interconnected to naturally develop plate-like crystalline regions possessing a certain size, and the α-crystallites with sufficient thicknesses possessed a cross-hatched phenomenon. The bundle-like supramolecular structure of the β-crystal induced by WBN-28 was further observed via a scanning electron microscope (SEM). The conformational changes in the crystallization process of PPR were resolved via high-resolution infrared spectroscopy to understand its β-crystallization in depth. The conformational changes during the crystallization of PPR were found to be different from those of the isotactic polypropylene homopolymer (PPH); they had their own characteristics. This will provide guidance for understanding the β-crystallization of PPR in depth. [ABSTRACT FROM AUTHOR]

In this study, the traditional mini split Hopkinson tension bar (SHTB) was enhanced for the dynamic mechanical performance testing of single fiber/resin interface of composites. Single Aramid III fibers were modified using a polyamine modification treatment. Quasi-static and dynamic tensile tests of modified single Aramid III fibers were conducted using an electronic tensile testing machine and mini SHTB. The test results indicated that the surface modification employing the Catechol-Tetraethylenepentamine (Cat-TEPA) approach had a negligible effect on the tensile mechanical properties of single Aramid III fibers. The microdroplet method was introduced to measure the dynamic interfacial shear strength (IFSS) of Aramid III fiber/waterborne polyurethane resin using a mini SHTB. The dynamic shear test results revealed an increase in the dynamic shear strength of the modified Aramid III fiber/resin interface from 36.16 MPa to 41.51 MPa. Furthermore, the Scanning Electron Microscope (SEM) photography of the modified single Aramid III fiber after debonding exhibited regular grid structures on the debonding area, which can prevent debonding between the single fiber and the microdroplet, thereby enhancing interfacial shear performance. [ABSTRACT FROM AUTHOR]

Due to the poor activation performance and kinetics of Ti50V25Cr25 alloys, the element Zr was added to improve the phase structure of the alloy and achieve a high-performance hydrogen storage alloy. The Ti50−xV25Cr25Zrx (x = 0, 5, 7, and 9) system alloys were prepared by arc melting. The alloys were analyzed using an X-ray diffractometer (XRD), scanning electron microscope (SEM), and differential scanning calorimeter (DSC). The hydrogen storage capabilities of the alloys were also obtained by the Sievert volumetric method. The results indicated that the alloy with Zr added had a combination of the C15 Laves phase and the BCC phase, whereas the Zr-free alloy had a BCC single phase. The partial replacement of Zr with Ti resulted in an increase in the lattice parameters of the main phase. The hydrogen storage kinetic performance and activation of the alloys both significantly improved with an increasing Zr concentration. The time to reach 90% of the maximum hydrogen storage capacity decreased to 2946 s, 230 s, and 120 s, respectively, with the increases in Zr concentration. The initial hydrogen absorption content of the alloys increased and then decreased after the addition of the element Zr. The second phase expanded with an increasing Zr concentration, which in turn decreased the abundance of the BCC main phase. The Ti43V25Cr25Zr7 alloy showed good cycle stability and hydrogen-desorption performance, and it could absorb 90% of the maximum hydrogen storage capacity in around 230 s. The maximum hydrogen-absorption capacity of the alloy was 2.7 wt%. The diffusion activation energy of hydrogen desorption dropped from 102.67 kJ/mol to 92.62 kJ/mol. [ABSTRACT FROM AUTHOR]

This paper discusses the electrochemical properties of thin-film, planar, titanium–platinum (Ti-Pt) microelectrodes fabricated using glass or silicon substrates and compares their performance to the classic platinum (Pt) microelectrodes embedded in glass. To analyze the possible differences coming both from the size of the tested electrodes as well as from the substrate, short- and long-term electrochemical tests were performed on selected water electrolytes (KCl, HCl, KOH). To study the electrochemical response of the electrodes, the cyclic voltammetry (CV) measurements were carried out at different scanning rates (from 5 to 200 mV/s). Long-term tests were also conducted, including one thousand cycles with a 100 mV/s scan rate to investigate the stability of the tested electrodes. Before and after electrochemical measurements, the film morphology was analyzed using a scanning electron microscope (SEM). The good quality of the thin-film Pt electrodes and the high repeatability in electrochemical response have been shown. There are minor differences in standard deviation values taken from electrochemical measurements, comparing thin-film and wire-based electrodes. Damages or any changes on the electrodes' surfaces were revealed by SEM observations after long-term electrochemical tests. [ABSTRACT FROM AUTHOR]

A synthetic flocculant of aluminum (Al) and iron (Fe) extracted from red mud (RM) has been widely used in sewage treatment, while the remaining RM residue has been ignored. This study aimed to synthesize polymeric aluminum ferric sulfate (PAFS) flocculant from RM by acid leaching and then use the acidified RM residue to produce an acid RM-based ceramsite (ARMC) by mixing bentonite, hydroxypropyl methylcellulose, and starch. Our results showed that sintering, reaction temperature, H2SO4 concentration, reaction time, and liquid-to-solid ratio had an obvious effect on the leaching of Al and Fe in RM, which was a necessary prerequisite for the efficient PAFS flocculants. At a PAFS dosage of 60 mg/L, turbidity and phosphate removal rates were 95.21 ± 0.64% and 89.17 ± 0.52%, respectively. When the pH value was 8.0, the turbidity and phosphate removal efficiency were 99.22 ± 0.66% and 95.98 ± 1.63%, respectively. Considering the adsorption capacity and mechanical properties, the best conditions for ARMC production included using 60% ARM and ceramsite calcination at 600 °C, with the BET surface area 56.16 m2/g and a pore volume of 0.167 cm3/g. Thermogravimetric analysis indicated that 400 °C was a reasonable preheating temperature to enhance the ARMC mechanical strength, as this temperature allows the removal of surface-adsorbed and constituent water. Under a scanning electron microscope, the ARMC appeared rough before adsorption, while relatively uniform pores occupied it after adsorption. Our conclusion will help to improve the zero-waste strategy of RM and speed up the industrial production of RM in flocculants as well as utilizing ARMC as a new type of adsorbent for phosphorus adsorption in sewage treatment. [ABSTRACT FROM AUTHOR]

The activity of biomaterials used during endodontic treatment can be affected by various factors. One of them is the chemical action of the irrigant that they are exposed to. The aim of this multimethod ex vivo study was to evaluate the influence of ethylenediaminetetraacetic acid (EDTA) on the surface appearance and chemical composition of Biodentine used in perforation repair. Twenty material specimens were prepared according to manufacturers' recommendations and divided into two setting-time-based groups, tested after 45 min (group A) and 24 h (group B) of setting. Material was irrigated with 17% EDTA solution with or without simultaneous ultrasonic activation. The surface characteristics and the chemical composition analysis of the Biodentine specimens were performed with the aid of a scanning electron microscope (SEM) and an energy dispersive spectroscopy (EDS) method, respectively. The volumetric loss of material was measured by dedicated digital software in an optical microscope. Statistical analysis was performed. The EDS study confirmed that after the rinsing protocol, the percentage content of elements differed between the groups. The EDTA rinse, whether ultrasonically activated or not, visibly affected the surface appearance and chemical composition of Biodentine. The specimens' surface subjected to irrigation was more irregular under SEM than in a control group. The US activation of the liquid amplified its impact on the tested material. The average volume loss in group A after 5 min irrigation was 3.98 µm3 for each µm2 of the chosen area and it increased up to 7.74 µm3/μm2 after the ultrasonic activation. In group B, indicated volume loss values were 6.30 and 11.70 µm3/μm2 for 5 min irrigation without and with US activation, respectively. Using a 20 min irrigation time and ultrasonic activation increased it up to 32.71 µm3/µm2. Each rinsing protocol involving irrigation with ethylenediaminetetraacetic acid modified the surface features and the chemical composition of the evaluated hydraulic tricalcium silicate cement. Further research is needed to indicate the possible impact of the observed changes on its long-term clinical performance. [ABSTRACT FROM AUTHOR]

This paper examines the lithology, pore throat, and fluid characteristics of the reservoir in Liaohe Oilfield Block 3624, using group V rocks as an example, combining a high-temperature and high-pressure reaction still with other equipment such as a rock mechanics tester and a scanning electron microscope. This study also designs and develops three controlled variable experiments, including the subcritical steam reservoir rock dissolution experiment, the subcritical steam reservoir rock mineral composition transformation experiment, and the subcritical steam reservoir rock mineral mechanical property experiment, also making clear the rule of change on the part of the rocks in the deep and heavy oil reservoirs after the injection of subcritical steam. Experimental results reveal the following: (1) Steam causes the dissolution of rocks, and when the steam temperature is in the subcritical region, dissolution is visible. After a 350 °C subcritical steam treatment, the relative melting temperatures of the components of rock materials are substantially greater than the melting point of the cement holding them together, causing the cement to significantly dissolve and a secondary crack network to emerge. (2) The mineral composition of the rocks changes as a result of elevated temperatures, with various mineral transformation trajectories being recorded after various steam treatments. Montmorillonite in reservoir rocks is converted into minerals like illite and chlorite in the subcritical steam temperature range. Another element influencing the creation of secondary cracks on rock surfaces is the reciprocal transformation of minerals, which alters the cohesiveness among mineral components. (3) Rocks suffer thermal damage and changes to their mechanical characteristics as a result of high-temperature steam dissolution and mineral transformations; the severity of these changes increases with the steam temperature. [ABSTRACT FROM AUTHOR]

This study presents the effect of chitosan on the properties of zinc ferrite nanoparticles suitable for potential biomedical applications. The co‐precipitation method is employed to fabricate these bio‐composites that exhibit excellent microstructural properties. The X‐ray diffractometer (XRD) analysis confirms the presence of a cubic spinel structure in the zinc ferrite‐chitosan bio‐composites, indicative of their crystalline nature. Scanning electron microscope (SEM) imaging revealed spherical particles with a size distribution below 100 nm, demonstrating the successful synthesis of homogenous nanosized particles. Fourier transform infrared spectroscopy (FTIR) spectroscopy analysis identifies the active functional groups within the bio‐composites, providing valuable insights into the molecular structure and interactions present in the synthesized materials. The presence of chitosan is confirmed, highlighting its role in modifying the chemical composition and enhancing the biocompatibility of the samples. UV–vis absorption spectra analysis reveals that the samples exhibits absorbance within the visible range. Vibrating sample magnetometer (VSM) analysis demonstrates the superparamagnetic behavior of the samples. Remarkably, these formulated samples exhibit superparamagnetism with zero coercivity and a magnetization of ≈0.0125 emu g−1 at 5 kOe when doped with chitosan. These properties are crucial for potential biomedical applications making it a promising candidate for various biomedical applications. [ABSTRACT FROM AUTHOR]

Background: Escherichia coli is a common fecal coliform, facultative aerobic, gram-negative bacterium. Pathogenic strains of such microbes have evolved to cause diarrhea, urinary tract infections, and septicemias. The emergence of antibiotic resistance urged the identification of an alternative strategy. The use of lytic bacteriophages against the control of pathogenic E. coli in clinics and different environmental setups (waste and drink water management) has become an alternative therapy to antibiotic therapy. Thus, this study aimed to isolate and characterize lytic bacteriophage from various sources in Addis Ababa, tested them against antimicrobial-resistant diarrheagenic E. coli strains and evaluated their therapeutic potential under in vitro conditions. Methods: A total of 14 samples were processed against six different diarrheagenic E. coli strains. The conventional culture and plaque analysis agar overlay method was used to recover lytic bacteriophage isolates. The phage isolates were characterized to determine their lytic effect, growth characteristics, host range activity, and stability under different temperature and pH conditions. Phage isolates were identified by scanning electron microscope (SEM), and molecular techniques (PCR). Results: In total, 17 phages were recovered from 84 tested plates. Of the 17 phage isolates, 11 (65%) were Myoviridae-like phages, and 6 (35%) phage isolates were Podoviridae and Siphoviridae by morphology and PCR identification. Based on the host range test, growth characteristics, and stability test 7 potent phages were selected. These phages demonstrated better growth characteristics, including short latent periods, highest burst sizes, and wider host ranges, as well as thermal stability and the ability to survive in a wide range of pH levels. Conclusions: The promising effect of the phages isolated in this study against AMR pathogenic E. coli has raised the possibility of their use in the future treatment of E. coli infections. [ABSTRACT FROM AUTHOR]

Silicon nitride (Si3N4) has great potential for applications in photoelectric and semiconductor fields. In this study, a novel strategy of fabricating Si3N4 crystals is reported, and the morphology of α-Si3N4 can be controlled. The aBN/SiO2/Si wafers were designed and irradiated by a high-energy electron beam for 2 min using home-made equipment. Tree-like α-Si3N4 dendrites and [001]-oriented unbranched α-Si3N4 whiskers can be synthesized by controlling the electron beam energy. Related formation mechanisms were analyzed based on componential and structural characterization using a scanning electron microscope and high-resolution transmission electron microscope. In addition, photoluminescence measurements indicate that the synthesized α-Si3N4 exhibit unique photoluminescence properties. This is attributed to α-Si3N4 forming abundant Si–Si bonds, Si dangling bonds, N dangling bonds and oxygen bonds in the synthesis process. These findings provide new insights into fabricating high-quality Si3N4 crystals, as well as developing related high-performance micro- or nano-devices. [ABSTRACT FROM AUTHOR]

Cationic exchange resins are used in nuclear power circuits to remove the nuclide ions to maintain the safe and efficient operation of nuclear power plants. Meanwhile, the production of spent resins is expanding significantly due to the rapid technological advancements in the nuclear industry, causing the study of resin treatment to be of great significance. This study reveals the catalytic behavior of Mn from cation exchange resins during molten salt oxidation. Mn has many isotopic ions and a catalytic effect on the treatment process. Kinetic analysis reveals that the introduction of Mn decreases the activation energy of the styrene–divinylbenzene skeleton from 48.164 kJ mol−1 to 41.696 kJ mol−1 and decreases the degradation temperature of the resin by 78 °C. Compared to the original resin, the destruction and removal efficiency of Mn-doped cation exchange resin increased from 75.07% to 85.28% during molten salt oxidation at 650 °C. According to the scanning electron microscope analysis and characterization studies, Mn promotes a 55.71% reduction in the average particle diameter of resin structural fragments. Fourier-transform infrared spectroscopy analysis of the resin residues demonstrates that Mn doping influences the catalytic decomposition of –SO2– and S–O within sulfonic acid groups. This catalytic effect induces destabilization and subsequent ring-opening of the benzene ring. These results imply that Mn doping can facilitate molten carbonate oxidation destruction of cation exchange resins. The X-ray diffraction analysis of waste salt reveals that with increasing oxidation time, the transformation of Mn proceeds as (Mn2O6)6− → (MnO3)2− → (MnO2)− at 750 °C. [ABSTRACT FROM AUTHOR]

SrFe 12 O 19 is widely used due to its low cost, stability and corrosion resistance. In this study, Sm-doped porous SrFe 12 O 19 powder with high coercivity was synthesized using KCl- assisted spray pyrolysis. The Sm doping, microstructure and magnetic properties were studied by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM). The results showed that when Sm-doping amount was 0.2, the ferrite powder prepared by KCl-assisted spray pyrolysis had high coercivity of 7.286 kOe and saturation magnetization of 56.422 emu/g. The coercivity of the Sm-doped samples increased by 39.23 % compared with that of the undoped samples. The significant increase in coercivity was associated with the improvement of super-exchange interaction between Fe3+ particles caused by Sm doping, and the size decrease of the hexagonal plate Sr-ferrite particle caused by KCl action. The influencing mechanism of coercivity was discussed in detail based on the analysis of crystal structure and microstructure observation. [ABSTRACT FROM AUTHOR]

The low-velocity impact (LVI) characteristics and compression after impact (CAI) properties of aircraft composite laminates under the influence of ultraviolet (UV) radiation were studied. Firstly, 0, 30, 60, 90 days of UV radiation experiments were carried out on the specimens to analyze the characteristics of the surface topography. Secondly, LVI experiments, the impact energies of 10, 17, and 25 J, were carried out on specimens to analyze the impact response laws and the characteristics of the impact instantaneous deformation. Finally, through CAI experiments and scanning electron microscope (SEM) techniques to clarify the influence mechanism of UV radiation on the residual compressive strength of specimens. The results showed that with the increase of UV radiation time, the shrinkage and erosion phenomena of the surface matrix and the exposure degree of the surface fibers were gradually increased, and the surface fibers were completely exposed after 90 days of radiation. At the same impact energy, with longer radiation time, the peak force gradually decreased (from 8673.86 to 7851.68 N at 17 J), the absorbed impact energy (from 9.48 to 11.13 J at 17 J) and maximum displacement (from 4.1 to 4.73 mm at 17 J) increased, the depth of pit on the impact surface decreased (from 0.213 to 0.14 mm at 17 J), and the internal damage projection area increased (from 906.68 to 1158.66 mm2 at 17 J). The compression damage of the specimens not exposed to/exposed to UV radiation was mainly fiber cracking/interlayer delamination, respectively. Highlights • Ultraviolet (UV) radiation makes the matrix of surface shrink, the fibers exposure increase. • The Stage II has obvious oscillation phenomenon in four stages of the lowvelocity impact process. • With prolonged UV radiation, the projected area of internal damage expands. • The residual compressive load increases with the increase of UV radiation time. [ABSTRACT FROM AUTHOR]

The study aimed to investigate the impact of high velocity oxy-fuel (HVOF) spraying parameters on the inflight particle temperature, velocity, and microstructure of FeCrMnCoNi high-entropy coatings (HECs). The sprayed coatings exhibited a typical lamellar structure with a single solid solution FCC phase and minor oxides. Ex-situ characterization of the coatings was conducted using X-ray diffraction, Raman spectroscopy, and high-resolution scanning electron microscope (HR-SEM) to analyze the phase composition, microstructure, and surface morphology. The findings revealed that fuel-rich flames with a higher feed rate resulted in coatings with low porosity and oxidation as well as high deposition efficiency due to the high velocity and low particle temperatures. Additionally, the transverse scratch tests were conducted to determine the cohesive/adhesive nature of the coatings, and the results demonstrated that the cohesive strength between the splats was influenced by the porosity and area fraction of the oxides. Coatings deposited with oxygen-rich conditions showed maximum hardness, but low cohesive strength compared to coatings sprayed using fuel-rich conditions due to higher oxides formation during spraying. The microstructural changes, phase compositions, and microhardness of the coatings were correlated with the scratch resistance of the HECs developed using three distinct spraying conditions. These results suggest that FeCrMnCoNi HECs hold significant potential for surface protection in various industrial and aerospace applications. Moreover, the findings point toward new material design strategies to attain desired microstructure with enhanced mechanical properties. [ABSTRACT FROM AUTHOR]

Background and objectives: Microbial cells capability to tolerate the effect of various antimicrobial classes represent a major worldwide health concern. The flexible and multi-components nanocomposites have enhanced physicochemical characters with several improved properties. Thus, different biological activities of biosynthesized starch/silver-selenium nanocomposite (St/Ag-Se NC) were assessed. Methodology: The St/Ag-Se NC was biosynthesized using Cladosporium cladosporioides CBS 174.62 (C. cladosporioides) strain. The shape and average particle size were investigated using scanning electron microscope (SEM) and high-resolution transmission electron microscope (HR-TEM), respectively. On the other hand, the St/Ag-Se NC effect on two cancer cell lines and red blood cells (RBCs) was evaluated and its hydrogen peroxide (H2O2) scavenging effect was assessed. Moreover, its effects on various microbial species in both planktonic and biofilm growth forms were examined. Results: The St/Ag-Se NC was successfully biosynthesized with oval and spherical shape and a mean particle diameter of 67.87 nm as confirmed by the HR-TEM analysis. St/Ag-Se NC showed promising anticancer activity toward human colorectal carcinoma (HCT-116) and human breast cancer (MCF-7) cell lines where IC50 were 21.37 and 19.98 µg/ml, respectively. Similarly, little effect on RBCs was observed with low nanocomposite concentration. As well, the highest nanocomposite H2O2 scavenging activity (42.84%) was recorded at a concentration of 2 mg/ml. Additionally, Staphylococcus epidermidis (S. epidermidis) ATCC 12,228 and Candida albicans (C. albicans) ATCC 10,231 were the highly affected bacterial and fungal strains with minimum inhibitory concentrations (MICs) of 18.75 and 50 µg/ml, respectively. Moreover, the noticeable effect of St/Ag-Se NC on microbial biofilm was concentration dependent. A high biofilm suppression percentage, 87.5% and 68.05%, were recorded with S. epidermidis and Staphylococcus aureus (S. aureus) when exposed to 1 mg/ml and 0.5 mg/ml, respectively. Conclusion: The biosynthesized St/Ag-Se NC showed excellent antioxidant activity, haemocompatibility, and anti-proliferative effect at low concentrations. Also, it exhibited promising antimicrobial and antibiofilm activities. [ABSTRACT FROM AUTHOR]

In order to study the effects of notched parameters on the hydrogen embrittlement (HE) behaviors of pipeline steel in hydrogen-blended natural gas environments, the mechanical properties of notched X80 steel specimens with various depth (δ), angle (ω) and curvature radius (ρ) were studied using slow strain rate tensile (SSRT) tests combined with scanning electron microscope (SEM) and finite element analysis (FEA). The tests indicate that the presence of notches greatly reduces the fracture strain, and increases the sensitivity of the specimen to HE. The geometric shape of the notch greatly affects the HE sensitivity of the notch specimen. The sharper the geometric shape of the notch, the higher the hydrostatic stress at the notch root, and the higher the diffusion hydrogen concentration, thereby increasing the hydrogen embrittlement sensitivity of the specimen. In addition, specimen with shallow notches also exhibits high hydrogen embrittlement sensitivity due to its shorter hydrogen atom diffusion distance. • The sharper the notch geometry, the higher the hydrogen embrittlement sensitivity. • The shallower the notch, the easier hydrogen atoms accumulate at the notch root. • The hydrostatic stress distribution affects hydrogen concentration distribution. • The lower stress concentration, the lower hydrogen embrittlement sensitivity. [ABSTRACT FROM AUTHOR]

Ruthenium (Ru) doped antimony tungstate microflowers, prepared through hydrothermal process, have been investigated for simultaneous adsorption and photocatalysis. The pattern of evolution of microflower structures, however, can be tailored by the synthesis period. This change is observed from the field effect scanning electron microscope and transmission electron microscope images. A possible mechanism behind this morphological change has been developed. An argument based on the zeta potential may be responsible for this distinct morphology due to the strong electrostatic interactions. The variation of a particular x-ray diffraction peak corresponding to the plane { 012 } with variation of Ru doping percentage shows the decrease in crystallinity along the perpendicular direction to this plane. Besides, the optimum Ru doping percentage is evaluated on the basis of photocatalytic efficiency towards methylene blue (MB) degradation under visible light. The highest dye removal efficiency is observed for 2% Ru doped Sb2WO6 (SWO) adsorbing 97% of the MB dye followed by photocatalytic degradation of almost 64% of the remaining dye in 80 min. Furthermore, using different dyes, it is concluded that Ru–SWO showcases high adsorption toward the cationic dyes while it neither adsorbs the anionic dye nor displays photocatalytic degradation. [ABSTRACT FROM AUTHOR]

Phosphorus (P) removal is a significant issue in wastewater treatment. This study applies Fe-Al composite coagulant to the advanced treatment of different P forms in biological effluent. For 90% total P removal, the dosage of FeCl3-AlCl3 composite coagulant reduces by 27.19% and 43.28% than FeCl3 and AlCl3 only, respectively. Changes in effluent P forms could explain the phenomenon of composite coagulant dosage reduction. The suspended P in the effluent of composite coagulant is easier removed by precipitation than single coagulant. In this study, the hydrolysis speciations of Fe3+, Fe2+, and Al3+ at a pH range are calculated by Visual MINTEQ. Changes in the morphology of metal hydroxides correlate with P removal at pH 4–9. Besides, analyses of scanning electron microscope (SEM), Fourier transformed infrared (FTIR), and X-ray photoelectron spectroscopy (XPS) are performed on the coagulation precipitations. Fe2+ reacts directly with P to form flocs of Fe3(PO4)2, and Al2(SO4)3 assists in the sedimentation of the small-volume flocs. Al13 is a significant hydrolysis product of Al3+, and Fe and P would substitute for the peripheral AlVI of the Al13 structure to form stable Fe–O–Al covalent bonds. [ABSTRACT FROM AUTHOR]

This study aims to investigate the properties of B. griseipurpureus Corner concerning its efficacy against various bacterial strains and its antioxidant capacity, along with its phytochemical composition. The antibacterial activity was evaluated using the agar well diffusion method, revealing pronounced efficacy against gram-negative bacteria, particularly noteworthy against E. coli ESBL182, known for its antibiotic resistance. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of B. griseipurpureus Corner extract against E. coli ESBL182 were determined to be 75 and 300 mg/ml, respectively. The extract exhibited bacteriostatic activity by inhibiting cell growth, leading to a reduction in optical density at 600 nm. Additionally, examination of the supernatant from untreated and treated E. coli ESBL182 cells with B. griseipurpureus Corner extract indicated absorbance values of 0.088 and 0.248 at 260 nm, and 0.045 and 0.286 at 280 nm, respectively. Further investigation utilizing a scanning electron microscope revealed alterations in the morphology of treated cells, which displayed elongation and fragmentation, in contrast to untreated cells. The DPPH assay indicated that the IC50 of B. griseipurpureus Corner extract was 31.22 mg/ml. The IC50 value obtained from the ABTS assay was 47.31 mg/ml. Additionally, the FRAP assay revealed that the concentration of ascorbic acid equivalent in B. griseipurpureus Corner extract was 1.06 mg/g crude extract. Phytochemical analysis, conducted using a spectrophotometer at wavelengths of 750 nm and 510 nm, respectively, indicated phenolic and flavonoid contents of 0.22 mg gallic acid/g fresh weight and 3.23 mg quercetin/g fresh weight in the extract. [ABSTRACT FROM AUTHOR]

The economic spray pyrolysis process were used to prepare Zinc oxide thin films. Ahigh - quality thin film is obtained by optimizing factors that include concentration, flow rate, nozzle to substrate distance. The temperature is differed between 350°C to 450°C. The structural and optical qualities were studied through physical investigation. According to XRD, the films have a hexagonal crystal structure. A scanning electron microscope reveals the material's uniform deposition &adhesion across a glass substrate. A direct band gap of about 2.4 to 2.6 eV was obtained for different temperatures. [ABSTRACT FROM AUTHOR]

In this present study, the fused deposition modeling (FDM) method was used to fabricate the composites. Before three-dimensional (3D) printing, samples were designed according to the ASTM D256, D790 and D3039 standards for impact, flexural and tensile tests, respectively, using Onshape software before conversion to an STL file format. Afterward, the digital file was sliced with infill densities of 60%, 80%, and 100%. The composite samples contained chopped carbon fiber (cCF) and poly lactic acid (PLA), as reinforcement and matrix, respectively. The cCF/PLA (simply called cCFP) filaments were printed into various cCFP composite (cCFPC) samples, using a Viper Share bot 3D machine with different infill densities before the aforementioned mechanical testing. The tensile strength of cCFP were obtained as 25.9MPa, 26.9MPa and 34.75MPa for 60%, 80% and 100% infill density cCFP samples, respectively. Similarly, the flexural strength of cCFP were obtained as 11.8MPa, 12.55MPa and 18.4MPa and impact strength was 47.48kJ/m2, 48.45kJ/m2 and 48.96kJ/m2 for 60%, 80% and 100% infill density cCFP samples, respectively. The fractured/tested samples were examined and analyzed under a scanning electron microscope (SEM) to investigate the presence of fiber and void in the tensile sample. Based on the experimental results, it was evident that a high infill density of 100% with the highest reinforcement exhibited maximum impact strength, tensile and flexural strengths and moduli when compared with other lower carbon content of cCFPC samples. Therefore, the optimal 3D-printed cCFPC sample could be used for engineering application to benefit from properties of the polymer matrix composite materials and possibilities through additive manufacturing (AM). [ABSTRACT FROM AUTHOR]

Cadmium sulfide quantum dots were synthesized and deposited on glass substrates by chemical bath deposition (CBD) technique using cadmium sulfate and thiourea solutions in the presence of a 4,4’-(1,2-ethanediyldinitrilo)bis-(2-pentanone) (EDDBP) tetradentate ligand as a complexing agent. The order of reagents addition was varied to deposit films that were characterized for their surface morphological, optical, structural, and solid-state properties using a scanning electron microscope (SEM), a UV-visible spectrophotometer, an X-ray diffractometer (XRD), and Brunauer-Emmet-Teller (BET) analyses. The optimal condition for film deposition using the normal sequence of reagents addition was found at pH 8-12 and 298-353 ± 1K and gave films of 2.40-321.06 nm thickness, while the variation in the order of reagents addition gave improvements in the film properties. The optical properties and the observed direct band gaps (1.75-3.16 eV) of the films suggest usage in electroluminescent and solar cell devices since they have a first-order transition. The XRD patterns of the quantum dots indicated hexagonal wurzite structures, while the BET confirmed their mesoporous and nanonature. [ABSTRACT FROM AUTHOR]

This study reports the successful synthesis and characterization of a uranyl nicotinate compound, UO2(C6H4NO2)2·0.25H2O. The compound was synthesized using a metal 1:2 ligand ratio and water as the solvent. The average yield of the compound was 67 %. Thermogravimetric analysis revealed multiple stages of mass loss, including dehydration, nitrogen decomposition and UO2 2+ reduction. Fourier-transform infrared spectroscopy confirmed the coordination of the carboxylate group in the compound. Field emission gun scanning electron microscope analysis showed the particles with a regular oval shape. Energy-dispersive X-ray spectroscopy provided semi-quantitative data on the elemental composition of the compound. The major elements identified were uranium, carbon, oxygen and nitrogen. These results contribute to understanding the compound's synthesis, thermal behaviour, molecular composition, particle morphology and elemental composition. Further research can build upon these findings to explore potential applications and develop new compounds with tailored properties. [ABSTRACT FROM AUTHOR]

In this study, aqueous Cystoseira crinite extract was used to successfully biosynthesize ZnO and C-doped ZnO samples. X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray (EDX), FTIR, and UV–vis techniques were used to characterize the biosynthesized samples. XRD technique confirmed the crystalline structure of ZnO and C-doped ZnO. EDX confirmed the formation of C-doped ZnO. SEM analysis revealed the spherical shape of the samples with agglomeration. FTIR spectra showed that phenolic compounds and protein molecules are present in the Cystoseira crinite extract. The photocatalytic activity of the prepared photocatalysts was investigated using crystal violet (CV) as a model of the cationic dyes and methyl orange (MO) as a model of the anionic dyes. 5%C-doped ZnO calcined at 500 °C showed an optimum photocatalytic efficiency of 92.7% and 87.8% for CV and MO dyes, respectively. The improved photocatalytic activity could be attributed to the narrower optical band gap of C doped ZnO than pure ZnO. The photocatalytic activity of CV and MO dyes follows the first-order kinetics with high correlation coefficient values. [ABSTRACT FROM AUTHOR]

The main goal of this work is to study the effects of some transition metal-oxides, i.e. ZnO, TiO2, and Fe2O3, on inhibition of spinel formation during cordierite fabrication from granite waste, talc, and alumina by direct coagulation casting method. Moreover, the effect of these oxides on sinterability, microstructure, hardness and electrical properties was achieved. The casted specimens were sintered at different temperatures then examined by X-ray diffraction technique to follow the formed phases. The physical properties were determined according to Archimedes rule. The microstructure was also investigated by scanning electron microscope, while the hardness was determined by Vicker's method. The electrical properties were evaluated by an impedance analyzer. The results indicated that sintered cordierite-spinel ceramics were successfully prepared with inhibition of spinel formation after addition of some transition metals and sintering up to 1250 °C. ZnO promoted the formation of spinel while TiO2 and Fe2O3 inhibited the formation of spinel and promoted the formation of cordierite. The ZnO-containing cordierites exhibited their best properties after sintering at 1200 °C, while the samples containing TiO2 and Fe2O3 showed their best properties after sintering at 1250 °C. The physical, mechanical and electrical properties were improved after increasing the amount of added metal oxides. The dielectric constant values were higher for the samples that contain TiO2 than those contain Fe2O3 and ZnO. Moreover, the hardness of all samples was in a narrow range of 6.14–6.61 GPa. [ABSTRACT FROM AUTHOR]

In this study, Chrysothemis pulchella leaf extracts were used to prepare gold nanoparticles (AuNPs) for anticancer and antimicrobial applications. The nanoparticles were characterized using UV-Visible spectroscopy, powder X-ray diffraction method, Scanning and transmission electron microscopic (SEM/TEM) techniques. The UV–vis spectroscopy revealed characteristic absorption band at 527 nm whereas X-ray diffraction analysis showed characteristic crystalline peaks typical of AuNPs and carbon peaks emanating from the plant extract. The energy dispersive X-ray spectroscopic (EDXS) studies showed the following elements: C, O, Na, Mg, Cl, K, Ca and Au. The microscopic analysis using Scanning and Transmission Electron Microscopes showed spherical nanoparticles with average size of 14.7 nm. Cytotoxic tests showed that the AuNPs were toxic to human embryonic kidney (HEK-293) and HELA cells at IC50 dosage of 34.5 and 54.05 µg respectively. The nanoparticles also proved to have broad spectrum antimicrobial properties as they inhibited the growth of some pathogenic micro-organisms. [ABSTRACT FROM AUTHOR]