Scanning Electron Microscopy Methods Research Articles

Laser synthesis of oxide nanoparticles with controlled gas condensation

In this work, the oxide nanopowders of Al2O3, ZrO2, Y2O3, Gd2O3, CeO2, and SiO2 were synthesized by CW CO2 laser vaporization technique with controlled gas condensation in an inert atmosphere. Methods for controlling the size of the resulting nanoparticles by adjusting the gas composition and pressure during the vaporization process have been demonstrated. The potential for producing ultrasmall oxide nanoparticles with dimensions less than 5 nm has been shown. The size distribution of nanoparticles taken from different parts of the evaporation-condensation tract was studied using scanning (SEM) and transmission (TEM) electron microscopy methods. The effect of synthesis conditions (pressure and composition of the inert gas) on characteristics of the nanoparticles is discussed. Using a wide class of simple oxides as the example, it is shown that the powders synthesized by the laser method consist of three types of particles: target spherical particles with a diameter of 3–20 nm (more than 98%), larger spherical particles with a diameter of 50–200 nm, and shapeless large particles with sizes more than 200 nm. The possibility of separating large particles from the main particles using the original labyrinth system for gas pumping is shown. The obtained particles with controlled sizes can be effectively used in various applications, in particular, for the preparation of catalysts and adsorbents.

Application of digital image correlation for in-situ deformation studies using transmission electron microscopy

Digital Image correlation (DIC) is routinely applied using optical and scanning electron microscopy methods to map local strains during deformation. In this letter, we report its use for in-situ TEM imaged deformation evolution for a nanocrystalline metal. Since transmitted electrons give rise to complex contrast conditions, with such contrast associated with the mechanisms of deformation, one can track these changes if particular care is done in image analysis and interpretation. We describe these methodologies to enable this correlation through frame averaging. Using these collective correlation conditions, we found that the average DIC strain matches well with the far field strain values yielding increased confidence in its application. Through the utilization of DIC in the TEM, nanoscale deformation mechanisms can be further elucidated because of the increased spatial resolution offered by TEM.

Endohelminth diversity in the invasive Clarias gariepinus (Burchell, 1822) from two freshwater lakes: Naivasha and Ol'Bolossat, Kenya.

Fish parasitology contributes to our understanding of the potential risks posed by diverse groups of parasitic organisms on fish stocks in either wild and culture systems. This study was conducted in May 2023 and aimed at assessing the diversity of endohelminths in the invasive North African catfish Clarias gariepinus (Burchell, 1822) obtained from two freshwater lakes, Naivasha and Ol'Bolossat, in Kenya. Parasitological examination of 66 and 35 fish samples collected from the two lakes respectively was achieved using light and scanning electron microscopy methods. Results revealed endohelminth diversity broadly classified as four digeneans, two nematodes, and one cestode. Seven taxa of endohelminths were found in C. gariepinus samples, but only four of these taxa could be identified up to the species level. Six of the taxa (Diplostomum sp., Tylodelphys mashonense, Plagiorchioidea sp., Paracamallanus cyathopharynx, Contracaecum sp., and Tetracampos ciliotheca) were common in samples from the two lakes. Glossidium pedatum only occurred in samples from Lake Ol'Bolossat. Parasite prevalence ranged from 8.6 (T. mashonense) to 100% (Diplostomum sp., T. ciliotheca, and Contracaecum sp.) and mean intensity from 1.4 (T. mashonense) to 16.9 (Diplostomum sp.). The diversity and richness indices were comparatively higher in fish samples from Lake Ol'Bolossat and attributed to the occurrence of G. pedatum in the Ol'Bolossat. However, parasitic infestation of fish samples from the two lakes depicted close similarity, both in diversity and prevalence. These findings form an important baseline data for further follow-up studies, and they suggest the need for further molecular analyses to fully describe three of the taxa only identified up to the genus level.

Scratching of metallized polymer films by Vickers indenter as a method for controlled production of SERS-active metasurfaces

The opportunities of a system of parallel microscratches drowed on a PET film metallized with silver and copper using a Vickers indenter as an active Surface-enhanced Raman spectroscopy (SERS) or Photoluminescence-enhanced surface have been investigated. It is shown that the enhancement of the SERS signal for rhodomine is proportional to the total length of microscratches in the laser spot and increases after their application due to the relaxation of the polymer backing. The results of the microscratch geometry analysis by an atomic force microscopy and scanning electron microscopy methods indicate the probability of the location of “hot points” along the “dumps” of metal along the shores of scratches, as well as on nanoroughnesses along their inner walls.© 2017 Elsevier Inc. All rights reserved.

RESISTANCE OF FERRITE-PERLITE STEEL TUBING BRANCH PIPE METAL TO DESTRUCTION IN HYDROGEN SULFIDE MEDIUM

This paper discusses the problems of resistance of the metal of the tubing branch pipe (tubing) to the process of its destruction in a medium containing hydrogen sulfide and when exposed to external forces. A 73х73 tubing nozzle made of 38G2SFA steel was selected as the material for research. The tubing fragment was destroyed during production well operation. To establish the reasons for the failure of the tubing nozzle, a visual inspection was carried out, tests were performed to assess the hardness and mechanical properties, the microstructure and microtexture of the metal were analyzed using scanning electron microscopy (SEM) methods. To analyze the nature of the distribution of introduced defects, the mutual orientation of structural components and crystallographic texture, studies were carried out by the method electron backscatter diffraction (EBSD). Studies of the suspended branch pipe, which does not have chemical protection, showed that the cause of its destruction was hydrogen sulfide stress corrosion cracking (SSCC) as a result of hydrogen embrittlement and the action of external tensile forces exceeding the yield strength of the metal. It was established that as a result of the interaction of hydrogen sulfide of the distilled product with the metal of the branch pipe, hydrogen embrittlement of the material of the branch pipe occurred. The process of hydrogen embrittlement of the fragment was proved by detecting hydrogen blisters in the metal microstructure and establishing the process of coalescence of neighboring inclusions. In addition, the results of the test to measure the hardness of the metal along the wall thickness further supported the hypothesis of hydrogen embrittlement of the tubing. EBSD analysis showed that the threaded part of the branch pipe is characterized by a small size of structural elements and an increased density of introduced defects (geometrically necessary dislocations), which are a promising site for the deposition of molecular hydrogen. It is concluded that reaching the limit concentration of molecular hydrogen reduces the binding energy of metal atoms and this process initiates the formation of pores. It has been established that the development of cracks along large-angle grain boundaries is facilitated, and small-angle and coincidence site lattice (Σ3, Σ5, Σ11 and Σ13b) grain boundaries are active barriers to crack propagation. It has been shown that by optimizing the elemental composition of steel, controlling the microstructure, crystallographic texture, as well as the type and state of grain boundaries, new pipeline steels can be produced that are more resistant to SSCC.

Application of lactobacillus casei and lactobacillus plantarum to develop dried functional apple and banana.

The goal of this research was to create dried fruits loaded with probiotic microorganisms (Lactobacillus casei and Lactobacillus plantarum). In separate bottles for each probiotic microbe, apple and banana pieces have been submerged into the impermeability solution with gentle shaking. The vacuum pressure was applied. By the conclusion of the incubation time, L. casei and L. plantarum colonies were enumerated (CFU/g). The scanning electron microscope method was applied to confirm the penetration of impregnation solutions into the intercellular spaces of fruit tissue. On day 28, the population of L. plantarum was 5 log CFU/g for apples and 5.5 log CFU/g for bananas. After storage, the number of L. casei in apples was 5 log CFU/g and 5.5 log CFU/g, respectively. L. casei was found on the surface of apple and banana tissue. After one-week, whole phenolic content of probiotic-enriched bananas and apples augmented. After storage, the antioxidant activity of all samples decreased greatly. The sensory qualities of the samples were excellent throughout storage in terms of color, quality, scent, sensitivity, chewiness, and general adequacy. As a result, dried apples and bananas infused with L. plantarum and L. casei might be a novel probiotic meal. RESEARCH HIGHLIGHTS: Dried apples and bananas infused with L. plantarum and L. casei are novel probiotic meal. After one-week, whole phenolic content of probiotic-enriched bananas and apples augmented. The sensory qualities of the samples were excellent throughout storage in terms of color, quality, scent, sensitivity, chewiness, and general adequacy.

Experimental and mechanistic investigation on the plastic anisotropic deformation behavior of α-phase titanium alloy Ti-2Al-2.5Zr

Ti-2Al-2.5Zr is widely used in piping and structural support applications, however, the rolling forming process results in anisotropic deformation during service. This behavior has implications for the manufacturing processes and structural safety assessments in engineering applications. In this study, the plastic anisotropic deformation behavior of a rolled Ti-2Al-2.5Zr plate was investigated using uniaxial tensile tests along the transverse, normal, and 45° directions. Acoustic emission, electron backscatter diffraction, and scanning electron microscopy methods were used to investigate dislocation slip and twinning mechanisms. The results indicated that different microscopic deformation mechanisms caused the significant macroscopic anisotropy of Ti-2Al-2.5Zr. The primary mechanisms involved were prismatic <a> slip, pyramidal <c+a> slip, and {10-12} extension twinning. The stress direction determined the influence of each of these mechanisms during the yielding and plastic deformation phases. Application of the visco-plastic self-consistent model established the relationship between the macroscopic mechanical responses and microscopic deformation mechanisms. It was revealed that Ti-2Al-2.5Zr achieved its optimum strength when the initial texture aligned most of the grain c-axis at angles ranging from 30° to 50° relative to the deformation direction. This finding provides a direction for the texture design of Ti-2Al-2.5Zr in engineering materials.

Separation of Damage Mechanisms in Full Forward Rod Extruded Case-Hardening Steel 16MnCrS5 Using 3D Image Segmentation.

In general, formed components are lightweight as well as highly economic and resource efficient. However, forming-induced ductile damage, which particularly affects the formation and growth of pores, has not been considered in the design of components so far. Therefore, an evaluation of forming-induced ductile damage would enable an improved design and take better advantage of the lightweight nature as it affects the static and dynamic mechanical material properties. To quantify the amount, morphology and distribution of the pores, advanced scanning electron microscopy (SEM) methods such as scanning transmission electron microscopy (STEM) and electron channeling contrast imaging (ECCI) were used. Image segmentation using a deep learning algorithm was applied to reproducibly separate the pores from inclusions such as manganese sulfide inclusions. This was achieved via layer-by-layer ablation of the case-hardened steel 16MnCrS5 (DIN 1.7139, AISI/SAE 5115) with a focused ion beam (FIB). The resulting images were reconstructed in a 3D model to gain a mechanism-based understanding beyond the previous 2D investigations.

Влияние режимов лазерной наплавки на геометрические размеры стального трека

Introduction. Laser surfacing is one of the leading trends in the field of additive technologies, which consists in layer-by-layer build of material using a laser as an energy source. To obtain a high-quality product, it is necessary to select the optimal building parameters correctly. The problem is that such optimization is necessary for all equipment, since minor differences in its characteristics can make significant changes in the parameters of layer-by-layer build. In order to determine the optimal build mode, it is enough to analyze the effect of various equipment parameters on the characteristics of single tracks. Therefore, the purpose of this work is to determine the most important parameters of laser radiation that affect the surfacing process and the optimal mode for building a single track of chromium-nickel steel. The work investigated single tracks obtained by laser surfacing of powder from austenitic chromium-nickel steel AISI 316L. The optimization factors included such characteristics as laser power, beam speed, flow rate of supplied powder and laser spot size. The wavelength of laser radiation was 1.07 μm. Research methods. To determine the quality and geometric dimensions of single tracks, the macrostructure of cross sections of specimens was studied using metallography and scanning electron microscopy methods. Results and discussion. It is established that the optimal mode for growing single tracks of steel AISI 316L is characterized by a laser radiation power of 1,250 W and a scanning speed of 25 mm/s. In this case, the optimal powder consumption rate is 12 g/min, and the laser spot size is 4.1 mm. The work shows that the powder consumption and laser spot size have the greatest influence on the coefficient of effective use of powder material. By changing it, the surfacing performance can be increased by 10–15 %.

Developing a new ethylene glycol/H2O pretreatment system to achieve efficient enzymatic hydrolysis of sugarcane bagasse cellulose and recover highly active lignin: Countercurrent extraction

Improving pretreatment efficiency is a critical premise in achieving efficient biomass conversion, and obtaining high-performance natural polymers is the guarantee of high-value conversion of biomass. In this study, a new pilot-scale continuous countercurrent pretreatment reaction unit about ethylene glycol-alkali solution was designed for pretreating sugarcane bagasse in order to achieve efficient separation of the three major components of lignocellulose when expanding the scale of pretreatment, reduce lignin deposition on the fiber surface, and obtain highly active lignin and excellent enzymatic hydrolysis efficiency of cellulose. X-ray diffractometer (XRD), X-ray photoelectron spectrometer (XPS), brunauer-emmett-teller (BET) and scanning electron microscope (SEM) methods are used to analyze the structural properties of sugarcane bagasse before and after pretreatment, and high-performance liquid chromatography (HPLC) is used to analyze the monosaccharide components in the enzymatic solution. In addition, the structural properties of the recovered lignin are analyzed by gel permeation chromatography (GPC), 31P NMR and 2D-HSQC-NMR methods. The results indicate that the system can gain a high cellulose recovery of 92.99% along with a lignin removal of 95.33%, and recovered lignin has low lignin carbohydrate complexes, low condensation, and rich in phenolic hydroxyl groups for 1.95 mmol/g. Meanwhile, the countercurrent pretreatment system can effectively reduce the deposition of lignin on the cellulose surface, which is evidently superior to the non-countercurrent pretreatment and facilitates the efficiency of enzymatic saccharification of substrate, achieving a high glucose yield of 99% as well as a total sugar yield of 91.11%. The method efficiently separates biomass in a green manner, and solid residues are easily hydrolyzed, showing potential for industrial-scale production.

Comparison of mechanical stability and morphology study between tree fibres and shrub fibres reinforced epoxy bio-composites

The material properties of bio-composites reinforced with natural fibers from shrubs (Tinospora cordifolia and Ipomoea staphylina) and trees (Morinda citrifolia and Tamarindus indica) are investigated in this study. Evaluation of these bio-composites’ mechanical characteristics and microscopic structure was the main goal, with a comparison of the efficacy of shrub and tree fibers for use in future automobile structural parts, airplane interiors, and consumer goods in mind. Because of their unequal distribution within the polymer matrix, the characteristics of natural fibers and composite fibers made of epoxy resin were found to be insufficient. Utilizing an unprocessed natural fiber ratio of 50 % fiber-to-resin, the composites were fabricated by hand layup technique. The findings showed that the epoxy composite enhanced with Tamarindus indica fibers (TIF) demonstrated outstanding mechanical properties, achieving a tensile strength of 8.15 MPa and compression strength of up to 5.89 kN. The compositions of the composites were analyzed using scanning electron microscopy (SEM) methods.

The effect of fish collagen on the silver nanoparticles sizes and shapes using modified microwave-assisted green synthesis method and their antibacterial activities

This work aimed to produce silver nanoparticles (AgNPs) by efficient green synthesis techniques, namely rapid green synthesis and modified microwave-assisted green synthesis methods. The study used fish scale collagen (FsCol) as a stabilizer to assess its impact on the dimensions and configurations of AgNPs. Four samples were prepared with varying concentrations of FsCol. The synthesized AgNPs were characterized using Ultraviolet–visible (UV–vis) spectroscopy, scanning electron microscope (SEM), energy dispersive X-ray analysis (EDX), Fourier Transform Infrared Spectroscopy (FTIR), X-Ray diffraction analysis (XRD), Dynamic Light Scattering (DLS), and Transmission electron microscopy (TEM) techniques. The obtained sizes are as follows: 85 ± 15 nm, 70 ± 10 nm, 50 ± 10 nm, and 28–40 nm. The UV–vis spectroscopy revealed a shift in the absorbance peaks from 400 to 446 nm. The SEM method showed a spherical form in all of the samples. The element silver was detected in the EDX examination, along with the presence of oxygen (O) and carbon (C). The FTIR analysis revealed that the peaks seen at 3307 cm−1 were attributed to the stretching of O–H bonds, while the mountain at 1638 cm−1 belonged to the extension of N–H bonds (amide A). Additionally, the band observed at 1638 cm−1 indicated the presence of CO bonds (amide I).The 2140 cm−1 and 1302 cm−1 peaks may be attributed to the C2H2 group present in the plant components and the N–H bending (Amide III), respectively. The XRD pattern indicates that the synthesis process resulted in the formation of crystalline AgNPs. The particle sizes measured using DLS were 121 nm, 96.36 nm, 82.3 nm, and 48.50 nm. The TEM approach revealed that all samples had a spherical morphology with varying sizes: 80–100 nm, 50–80 nm, 40–60 nm, and 28–42 nm. The synthesized AgNPs were tested for their antibacterial properties against the pathogenic pathogens Escherichia coli (E.coli) and Staphylococcus aureus (S. aureus). The influence of AgNPs on bacteria was amplified as the particle size decreased, resulting in a larger inhibitory zone for the smaller particles.

Novel MAXPOWER biological antibacterial liquid for eradicating oral Helicobacter pylori

BackgroundEradication of oral Helicobacter pylori (H. pylori) not only reduces the infection rate from the transmission route but also improves the success rate of intragastric eradication. MAXPOWER Biological Bacteriostatic Liquid, developed in our previous work, is a composite biological preparation with strong antibacterial ability and unique antibacterial mechanism. The present study evaluated the efficacy of the MAXPOWER biocontrol solution on H. pylori and its success rate in eradicating oral H. pylori in clinical patients.MethodsLive-dead cell staining and hemolysis test were used to evaluate the cellular safety of MAXPOWER biocontrol solution; plate spreading, live-dead bacterial staining, and scanning electron microscopy methods were used to evaluate its antimicrobial effect against H. pylori. Transcriptomics was used to analyze the changes in H. pylori genes before and after treatment. After seven days of gavage treatment, H&E staining and mice feces were collected for 16SrDNA sequencing to evaluate the animals’ safety. Oral H. pylori-positive patients were randomized to be given a placebo and MAXPOWER Bio-Bacteriostatic Liquid gargle for seven days to evaluate the effect on oral H. pylori eradication.ResultsIn vitro tests demonstrated that this product has excellent biocompatibility and hemocompatibility and can effectively eradicate oral H. pylori. In vivo tests further showed that it has good biosafety and virtually no adverse effect on intestinal microflora. Transcriptomics analysis revealed that it kills H. pylori cells mainly by disrupting their cell membranes and metabolism. Additionally, the results of randomized controlled trials on humans disclosed that the oral H. pylori eradication rates achieved by MAXPOWER Biological Antibacterial Liquid were 71.4% and 78.9% according to the intention-to-treat and the per-protocol analysis, respectively.ConclusionMAXPOWER Biological Antibacterial Liquid is both safe and efficacious in the eradication of oral H. pylori.Trial registrationThis study was retrospectively registered in the ClinicalTrials.gov Trial Registry on 21/09/2023 (NCT06045832).

Synthesis and study of organo-modified silica based hydrogels: Rheological properties and drug release kinetics.

The method of synthesis of unmodified and organo-modified silica hydrogels and their composites with orotic acid as a model drug was developed. The hydrogels had a pH of 6.5-7.8. The particulate nature and highly porous structures of the hydrogel materials were revealed using scanning electron and optical microscopy methods. The content of aqueous phase in the hydrogels was 99% or more. In order to evaluate the possibility of their application as a basis for development of novel soft drug formulations and cosmetic compositions, rheological properties of the hydrogels and in vitro release kinetics of the drug were studied. The effects of synthesis conditions (increasing concentration of catalyst of silica sol formation, drug loading) and the silica matrix modification with various organic groups on the indicated properties were investigated. It was found that all synthesized hydrogels exhibited pseudoplasticity, thixotropy and controlled release of the drug, which are important for their potential application. However, in general, the indicated effects led to worsening the properties of the hydrogel materials in comparison with the unmodified silica hydrogels.

Effects of Mn and Ru substitutions on the electrical properties and AC susceptibility of Tl(BaSr)CaCu2O7 superconductor

In this paper, the effects of M = Mn and Ru substitutions at the Tl site of Tl[Formula: see text]Mx(BaSr)CaCu2O7 (Tl-1212) on the electrical properties and AC susceptibility were investigated. The X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) methods were used to examine the phase and microstructure, respectively. All samples showed diffraction patterns with Tl-1212 as the major phase and an increase in the Tl-1223 phase with increasing Mn and Ru substitutions. The microstructure showed partial melting and randomly oriented grains in all samples. The electrical resistance measurements showed metallic normal state behavior for all samples. The zero-resistance transition temperature [Formula: see text] was the highest for x = 0.4 where [Formula: see text] was 107[Formula: see text]K and 90[Formula: see text]K for Mn and Ru substitutions, respectively. The superconducting transition, [Formula: see text] obtained from AC susceptibility measurements increased with Mn and Ru substitutions up to x = 0.4. Using Bean’s model, the current density at the peak temperature of the imaginary part of the AC susceptibility, [Formula: see text]([Formula: see text] was determined to be between 16 and 22[Formula: see text]A[Formula: see text]⋅[Formula: see text]cm[Formula: see text] for Mn, and between 15 and 19[Formula: see text]A[Formula: see text]⋅[Formula: see text]cm[Formula: see text] for Ru-substituted samples. Mn substitution showed a higher transition temperature compared with Ru. This study showed that optimization of the average Cu valence was achieved with Mn and Ru substitutions for x = 0.4 at the Tl site. The ionic radii of the substituting and substituted elements are important factors in enhancing the transition temperature of Tl(BaSr)CaCu2O7 superconductor.

Advanced Chemical and Imaging Methods for Studying Structure Morphology and Excipients Solid State Transformations in Pharmaceutical Multiparticulate Formulations

The formulation of paediatric medicines faces significant challenges to meet the requirements for safe and accurate administration, while maintaining a suitable taste. Multiparticulate formulations have a strong potential to address these challenges because they combine dose flexibility with ease of administration. Understanding the stability of multiparticulate formulations over storage as a function of time and environmental parameters, such as humidity and temperature, is important to manage their commercialisation and use. In this work, we have expanded the toolkit of available techniques for studying multiparticulates beyond those such as scanning electron microscopy (SEM) and confocal laser scanning microscopy. We include advanced methods of environmentally-controlled SEM to monitor temperature- and humidity-induced changes in-situ, and a variety of Raman spectroscopies including stimulated Raman scattering microscopy to identify and localise the different ingredients at the surface and inside the multiparticulates. These techniques allowed unprecedented monitoring of specific changes to the particulate structure and distribution of individual ingredients due to product aging. These methods should be considered as valuable novel tools for in-depth characterisation of multiparticulate formulations to further understand chemical changes occurring during their development, manufacturing and long-term storage. We envisage these techniques to be useful in furthering the development of future medicine formulations.

Comparative physicochemical investigation of the inclusion compounds of cyclodextrins with arginine and histidine stereoisomers

The inclusion complexes of α-, β-cyclodextrin and 2-hydroxypropyl-α-cyclodextrin with two amino acid stereoisomers (L-, D-arginine and L-, D-histidine) were studied by using differential scanning calorimetry, thermogravimetry, Fourier transform infrared spectroscopy, and scanning electron microscopy methods. The solid inclusion compounds were prepared in a 1:1 molar ratio of the host and guest using the co-precipitation method. The pH measurements and structural visualization of complexes were carried out. The obtained results proved the formation of the complexes and revealed that the size and the symmetry of the cyclodextrin (CD) and also the structure and flexibility of the amino acid molecule had a significant influence on the complexation interaction. The correlation of the experimental data shows that βCD has a preference to form more stable complexes with levogir isomers of amino acid than αCD and 2-hydroxypropyl-α-cyclodextrin. The complexation of the amino acids isomers was accomplished by partial inclusion of the guest molecule in the CD cavity, and it was observed that CDs could better discriminate between histidine isomers than between arginine isomers.

Enhancing microstructure and mechanical properties of dissimilar TIG welded duplex 2205 and Ni-based inconel 718 superalloy through post weld heat treatment

In demanding applications, maintaining structural integrity in dissimilar welded joints like those between duplex stainless steel and Ni-based superalloys requires achieving the best possible mechanical properties. This work examines the impact of post-weld heat treatment (PWHT) on the mechanical characteristics of joints made via double-sided tungsten inert gas (TIG) welding. The dissimilar welded joint was investigated by exposing it to the PWHT for 12 h at 650 °C. Reducing the negative impact of heat generated by welding on the mechanical characteristics and microstructure of the fusion zone was the main goal. To study for changes in the microstructure before and after PWHT, optical microscopy and scanning electron microscopy methods were used for microstructural analysis. To determine the effect of PWHT on the welded joints, mechanical properties such as tensile strength, toughness, and ductility were also assessed. The mechanical properties showed significantly enhanced characteristics and refined grain structures in the fusion zone.

Luminescence properties of SrB6O10:Ce,Gd phosphor for applications in OSL dosimetry and lighting

Strontium hexaborate (SrB6O10) doped with different metals and/or lanthanides has been studied widely as the thermoluminescence (TL) dosimeter. However, there is almost no dosimetry study concerning the utility of Optically Stimulated Luminescence (OSL) on SrB6O10. This preliminary study aims to examine the luminescence properties of SrB6O10 phosphor for their application in the areas of dosimetry and lighting technologies. Undoped and doped material to get an OSL dosimeter were synthesized by incorporating the dopants Ce3+, in the range of 0.1–0.7 % wt, and Gd3+, in the range of 0.1–1 % wt into the SrB6O10 structure using the solution combustion (SCS) method. The structural and morphological characterizations were performed using X-ray diffraction (XRD) and Scanning Electron Microscope (SEM) methods, respectively. Two TL peaks of SrB6O10:Ce0.1%,Gd0.5% occurred at 70 °C and 182 °C after 1 Gy exposure to beta rays with a heating rate of 2 °C/s. The step annealing measurements were carried out to determine the traps responsible for the OSL signal. Various properties of the luminophore including dose-response and reusability were investigated using blue light stimulation. The phosphor showed a little variation of response up to 20 cycles within 2 % deviation (STD) from the first OSL readout. The OSL output within the range of 2–20 Gy was determined as linear. Radioluminescence (RL) measurement was investigated by emission in the range λem = 200–1000 nm. The parent compound displayed UV emission subdivided into UVA (315–400 nm), and UVB (280–315 nm) emissions at room temperature. The Chromaticity Coordinates (CIE) of SrB6O10:Ce0.1%,Gd0.5% were calculated as x = 0.2165, y = 0.1767. These remarkable characteristics show that, if developed, SrB6O10 could be used as an OSL dosimeter.

Thermomechanical evaluation of zinc oxide/hydroxyapatite/high‐density polyethylene hybrid composites

AbstractThis study examines the impact of zinc oxide (ZnO) on the spectral, thermal, mechanical, and morphological characteristics of developed composites of high‐density polyethylene (HDPE). Composite samples were fabricated with different compositions of ZnO (0, 5, 10, 15, and 20 wt%) along with a constant quantity of hydroxyapatite (HA, 10 wt%) in pure HDPE. The synthesized hybrid polymer composites were characterized using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), universal testing machine (UTM), and field emission scanning electron microscopy (FESEM) methods, allowing for a thorough assessment of their spectral, thermal, mechanical, and morphological properties, repectively. FTIR analysis revealed the presence of HA and ZnO metal vibrations in the hybrid polymer samples. The thermal stability was increased by the incorporation of different amounts of ZnO, and the decomposition temperature was increased from 319.31 to 412°C for 10 wt% of ZnO hybrid composites as compared to pure HDPE. DSC findings indicated that increasing the ZnO contents, prompted the degree of crystallinity to rise to 14.81% as contrasted to neat HDPE. It was observed that yield strength and ultimate tensile strength for the 10 wt% ZnO composite increased up to 51.85% and 31.72%, respectively, compared to pure HDPE. However, at higher loading of ZnO, surface cracks were observed, which is detrimental for composite materials. Hence, the improved attributes indicated that the synthesized ZnO/HA/HDPE polymer composites can be a promising material for biomedical engineering applications.