Scanning Electron Microscopy Studies Research Articles

Characterization of β-glucan obtained from Candida albicans of caprine mastitis

Background: Beta-glucan (β-glucan) is a polysaccharide containing β-glycosidic bonds that is an important structure part of different yeast cells. Aim: The purpose of the study is to characterize β-glucan that obtained from Candida albicans (C. albicans) isolated from caprine mastitis. Methods: The β-glucan was extracted by using utilizing an Alkaline-acidic extraction technique. The dry weight of extracted β-glucan was 7.47/150 gm with 4.98%. Results: The findings demonstrated that the extracted β-glucan had similarity in the primary peak 5.78 of liquid samples using the method of High-Performance Liquid Chromatography (HPLC) when compared to the standard form of β-glucan. However, Scanning Electron Microscopy (SEM) studies revealed which the standard of β-glucan was distinct in morphology but similar to β-glucan isolated from C. albicans in terms of particle sizes in the range of 1.60-2.65 m and the lack of cell wall traces. The findings of an investigation using Energy Dispersive X-ray Fluorescence Spectroscopy (EDS/EDX) of extracted and standard β-glucan, showed the principal elements discovered were carbon (C), oxygen (O), and nitrogen (N). Aluminum (Al), silicon (Si), nickel (Ni), and gold (Au) were also present, but in less amounts. Conclusion: The extracted β-glucan displayed a high degree of similarity and purity to the standard β-glucan, according to the findings of Fourier Transform Infrared Spectroscopy (FT-IR) research.

Effect of different irrigation activation systems using continuous chelating irrigation protocol on the removal of smear layer in the apical third of root canals: An in vitro scanning electron microscope study

Aim: Continuous chelation is a novel irrigation regimen popular as a single solution for irrigation of the root canal system during root canal therapy, especially for the removal of the smear layer. This study aimed to compare the effectiveness of three different irrigation activation systems in removing the smear layer from the apical third in single-rooted mandibular premolars using a scanning electron microscope (SEM). Methods: Fifty-six extracted single-rooted mandibular premolars were decoronated, and canals prepared till #30/0.09, with Chloroquick (3% NaOCl + 9% HEBP) as the working solution. Teeth were randomly divided into four groups based on the final irrigant activation protocol; Group A - (control group) conventional syringe irrigation with a 30-gauge single-side vented needle. Group B - (passive ultrasonic irrigation method) passive ultrasonic irrigation (PUI) with #20-Irrisafe ultrasonic files activated for 1 min. Group C - (sonic activation) EndoActivator system using the yellow tip (#20/0.04) activated for 1 min. Group D - Tornado Disinfection Kit using GF-brush for 20–30 s as per manufacturer’s instructions. The canals were dried, samples were hemi-sectioned, and the amount of remaining smear layer was scored according to the Tabrizizadeh criteria (2015) with SEM images at ×2500 by two blinded operators. The collected data were analyzed statistically using the Chi-square test (P < 0.05). Results: The results showed statistically significant differences in terms of smear removal among the groups (P < 0.05) with the Gentlefile group performing better, followed by PUI, EndoActivator, and the conventional group. Conclusion: Within the limitations of the study, continuous chelation with Gentlefile activation could be a viable and efficient protocol for the removal of the smear layer from the apical third of root canals.

A comparative study on morpho-anatomical characters of eight Huperzia species from Arunachal Pradesh, India

Morphology and anatomy of eight species of Huperzia from Arunachal Pradesh was studied here. Following the PPG1 classification the genus Huperzia belongs to the subfamily Huperzioidae under the family Lycopodiaceae of the order Lycopsida which falls under the class Lycopodiopsida. The genus is a medium size evergreen plant with a vertical or ascending stem, with linear toelliptical leaves which are smoothedged and spores are formed within the sporophylls. Scanning Electron Microscopic studies of the spores were also done. On the basis of all these observations keys to the species were prepared.

Efficacy of ultrasonics and Er,Cr:YSGG laser on root surface calculus removal: A comparative in vitro field emission scanning electron microscope study.

Scaling and root planing (SRP) is an inevitable primary step in non-surgical periodontal therapy. Debridement carried out with manual instruments and ultrasonics results in the removal of tooth structure. Current research revolves around laser as an efficient adjunct to SRP. This study evaluated and compared the effectiveness of root surface calculus removal between ultrasonics and Er,Cr:YSGG laser. Twenty-eight single-rooted teeth extracted due to periodontal disease were selected for the study. The specimens were randomly assigned to two groups (n=14). Group I underwent ultrasonic instrumentation using a piezo ultrasonic scaler, and group II was subjected to laser instrumentation using Er,Cr:YSGG laser (Waterlase). The specimens were processed, fixed, viewed under a field emission scanning electron microscope and evaluated using the remaining calculus index (RCI) and loss of tooth substance index (LTSI). Ultrasonics-treated specimens revealed more remaining calculus (1.57±0.65) and lost tooth substance (1.71±0.61) compared to the Er,Cr:YSGG laser-treated specimens, with significantly lower RCI (0.71±0.61) and LTSI (1.00±0.56). There was a statistically significant difference (P<0.05) in the efficacy of root surface calculus removal between the two groups. Compared to ultrasonics, Er,Cr:YSGG laser demonstrated superior results by causing precise removal of root surface calculus without significantly affecting tooth structure and aiding in new attachment.

Single Crystal Growth and Nano-Structure Study in a Topological Dirac Metal, CoTe2-δ

A single crystal of a topological material, CoTe2-δ, has been grown via the chemical vapor transport method for a structural and electronic transport study. Single-crystal X-ray diffraction, powder X-ray diffraction, and high-resolution scanning electron microscope measurements confirm the high quality of the as-grown single crystals. In a high-resolution scanning electron microscopy study, a clear layered feature of the trigonal CoTe2-δ crystal was observed. Fractal features and mosaic-type nanostructures were observed on the as-grown surface and cleaved surface, respectively. The trigonal CoTe2-δ demonstrates a metallic ground state in transport measurements, with a typical carrier’s concentration in a 1021 cm−3 magnitude and a residual resistivity ratio of 1.6. Below 10 K, trigonal CoTe2-δ contains quite complicated magnetoresistance behavior as a result of the competing effect between Dirac states and possible spin fluctuations.

Effects of Pollution on the Haematology of Cyprinus carpio Inhabiting two Government Sponsored Fish Ponds in East Khasi Hills District, Meghalaya, India

Adult Cyprinus carpio were collected from two government sponsored fish ponds located at Fish Dale and Laitkyrhong, East Khasi Hills District, Meghalaya, India. The effects of pollutants on haematological parameters of Cyprinus carpio were studied. The results showed a decline in RBC and WBC count and haemoglobin content in fishes collected from Laitkyrhong. Micronucleus assaywas carried out following standard protocols and observations were made using Olympus, BX- 53 image analyser, CellSens Standard (software). Analysis showed a number of micronucleus and nuclear abnormalities of the erythrocytes of Cyprinus carpio from Laitkyrhong as compared to fishes from Fish Dale. Scanning Electron Microscopy study revealed swollen erythrocytes called spherocytes, ruptured erythrocytes and crenations at the erythrocyte membranes while the control erythrocytes showed normal features. The Energy Dispersive X-ray Spectroscopic analysis was by INCA-7582 (Oxford) Energy Dispersive X-ray microanalyser equipped with a Si (Li) high resolution detector attached to the scanning electron microscope, JSM-6360 (Jeol). Differences in the EDS spectra of RBCs from control, Laitkyrhong and Fish Dale fishes were observed to be in terms of Silicon (Si), Aluminium (Al) and Titanium (Ti) were absent in the control sample. The presence of silicon in erythrocytes of fishes inhabiting Fish Dale and Laitkyrhong area suggests that silicon may be the main factor for the various deformities in the haematological parameters of Cyprinus carpio. The deformities observed may affect the growth and survival of these fishes. Therefore, there is a constant need to check the flow of polluted waters in the rearing ponds especially during the rainy seasons. The present study suggests that haematological study may serve as a tool in determining the health of the fish and the type of environment in which it lives.

Development and Characterization of Novel Chitosan-Coated Curcumin Nanophytosomes for Treating Drug-Resistant Malaria.

This study aimed at enhancing the efficacy of curcumin (CR) by formulating and coating it with chitosan. In silico molecular docking studies revealed that CR exhibited almost similar and low binding energies when compared to artemisinin, indicating high stability at the target site. It can be confirmed that CR is effective in treating and reducing Plasmodium falciparum parasites. Fourier transform infrared studies confirmed that there was a shift and disappearance of some drug peaks in the formulation which revealed complexation with phospholipids. The F2EXT3-developed formulation exhibited greater solubility (24.31 ± 3.47 μg/mL) when compared to pure CR (7.99 ± 1.95 μg/mL). Proton nuclear magnetic resonance studies confirmed the formation of Curcumin-phospholipid hydrogen bonding in F2EXT3. The in vitro drug release studies revealed that the developed formulation F2EXT3 exhibited better drug release at 71.98% at 48 h; this might be due to the effective entrapment efficiency of the drug inside the phospholipid, presence of polyethylene glycol 4000 and chitosan further assisted in sustained release of the drug. Scanning electron microscopy studies revealed that optimized F2EXT3 CR nanophytosomes were nearly spherical with narrow size distribution and smooth surface. The zeta potential of the F2EXT3 showed -3.5 mV. Stability studies revealed that the formulation remained stable even after 6 months. It was observed from the hemin assay that CR and F2EXT3 exhibited (50 μg/mL curcumin) exhibited IC50 values of 47 ± 2.45 and 22 ± 1.58 μM, respectively. Further in vivo antimalarial activity on resistant and sensitive strains needs to be performed to evaluate the efficacy of the developed formulation.

Synthesis of Plant-Mediated Iron Oxide Nanoparticles and Optimization of Chemically Modified Activated Carbon Adsorbents for Removal of As, Pb, and Cd Ions from Wastewater.

This research study was designed with the aim to prepare plant extract-mediated iron oxide nanoparticles (IONPs) and different chemically modified carbon adsorbents from the Parthenium hysterophorus plant and then optimize the carbon adsorbents by evaluating their adsorption applications in wastewater for the selected metal ions like arsenic (As3+), lead (Pb2+), and cadmium (Cd2+). The Fourier transform infrared spectroscopy (FTIR) technique was used to highlight functional groups in plant-mediated IONPs and chemically modified carbon adsorbents. A scanning electron microscopy study was conducted to explain the surface morphology of the adsorbents. Energy-dispersive X-rays was used for elemental analysis and X-ray diffraction for particle size and crystallinity of the adsorbents. From the study, it was found that the best optimum conditions were pH = 5-6, initial concentration of adsorbate of 10 mg/L, dose of adsorbent of 0.01 g, contact time of 90-120 min of adsorbent and adsorbate, and temperature of 25 °C. At optimum conditions, the adsorption capacities of IONPs for arsenic (As) 144.7 mg/g, lead (Pb) 128.01 mg/g, and cadmium (Cd) ions 122.1 mg/g were recorded. The activated carbon at optimum conditions showed adsorption capacities of 46.35 mg/g for As, 121.95 mg/g for Pb, and 113.25 mg/g for Cd ion. At equilibrium, Langmuir, Freundlich Temkin, and Dubinin-Radushkevich isotherms were applied on the experimental adsorption data having the best R2 values (0.973-0.999) by the Langmuir isotherm. High-correlation coefficient R2 values (0.996-0.999) were obtained from the pseudo-second-order for all cases, showing that the adsorption process proceeds through pseudo second-order kinetics. The apparent adsorption energy E value was in the range of 0.24-2.36 kJ/mol. The adsorption capacity of regenerated IONPs for As gradually decreased from 144.8 to 45.67 mg/g, for lead 128.15 to 41.65 mg/g, and cadmium from 122.10 to 31.20 mg/g in 5 consecutive cycles. The study showed that the synthesized IONPs and acid-activated carbon adsorbent were successfully used to remove selected metal ions from wastewater.

Synthesis of novel nanocomposite of g-C3N4 coated ZnO–MoS2 for energy storage and photocatalytic applications

Fabrication of heterostructures for energy storage and environmental remedial applications is an interesting subject of research that has been undertaken in this present investigation. The incorporation of g-C3N4 into ZnO:MoS2 heterojunction nanocomposite was accomplished by wet-chemical route and characterized by various techniques to ascertain its structure, morphology, and study its potential electro-optical characteristics. The g-C3N4@ZnO:MoS2 sample was investigated by x-ray diffraction (XRD) which reveals the co-existence of the ZnO, MoS2 and C3N4 phases linked to characteristic crystallographic planes in the spectrum, validating the formation of ternary nanocomposite. The XRD patterns of the pristine samples were also considered as reference to understand the structural evolution and phase transformations. Field emission scanning electron microscopy (FESEM) study states the formation of heterogeneous nanostructures having nanoparticles embedded on 2-D nanosheets like structures. Studies using energy dispersive spectroscopy (EDS) and elemental mapping show that all the elements that are linked to the above hybrid nanocomposite are present. Transmission electron microscopy (TEM) provided clear insights on the microstructure as we can identify the distribution of ZnO and MoS2 nanostructures on layered g-C3N4 nanosheets. The chemical composition and oxidation states of elements were elucidated by X-ray photoelectron spectroscopy (XPS) study, which added another layer of confirmation on the structural evolution of the ternary nanocomposite. Fourier transformed infrared (FTIR) study revealed the layered structure of sp2 hybridized bonding features of C and N in g-C3N4, besides Zn–O and Mo–S stretching vibrations. The nanocomposite demonstrated improved photodegradation efficacy and decomposed alizarin red and methylene blue dyes significantly with better stability and reusability. MoS2 as a co-catalyst acts as an electron acceptor/accelerator in the Z-scheme composite photocatalysis leading to improved photocatalytic efficiency. The resulting heterostructured material delivered a higher specific capacitance of 10.85 F/g with good capacitance retention. Electrochemical study revealed the energy storage capability of the hybrid system.

Transparent superhydrophobic coating for copper metal and study of surface morphology and antimicrobial characteristics

Nowadays, copper is a widely used metal worldwide for various applications such as electronic materials, electrical circuits, ornamentals and decorative applications. Copper is widely known for its antimicrobial properties. Despite this fact, it is found to be susceptible to biocorrosion. To protect the copper metal from biocorrosion, hydrophobically modified silica nanoparticles were prepared by the sol gel process. The Prepared sol solution was characterized by Particle size analysis, transmission electron microscopy (TEM) and infrared spectroscopy. Modified silica nanoparticles coated on the copper substrate to obtain superhydrophobic surface. Surface morphology was observed by scanning electron microscopy (SEM), electron dispersive microscopy (EDX) and atomic force microscopy analysis (AFM). Wettability and antimicrobial activity of the copper surface were also studied. The average particle size was found to be 96 nm and the formation of silica nanoparticle in the sol was also confirmed by IR spectra. The Contact angle of coated copper was found 163.3˚compared to 66.6˚ of uncoated copper surface which confirms the superhydrophobic behavior of the coated surface. The presence of nanostructured surfaces was responsible for superhydrophobic behavior which was confirmed by SEM and AFM studies. The coated copper showed excellent antimicrobial characteristics against E-coli.

Unveiling the Mechanisms of NMC622 Degradation during Cycling Using Ex Situ SEM, XRD, and Raman Studies

Lithium-ion cells that employ nickel-rich NMC materials are prevalent because of their high capacity and ability to function at significantly elevated potentials vs Li+/Li. Nonetheless, these cells encounter issues such as a decline in capacity or thermal resistance, and various researchers are currently exploring the underlying causes of these phenomena. Zhang1 has compiled these findings, pointing out the most significant ones: cation mixing, present of residual lithium compounds, oxygen evolution and phase transition to rocksalt. Understanding the phenomena occurring during lithiation and delithiation of NMC can help in selecting the appropriate method to improve its properties. To understand this, scientists use various methods. Through a scanning electron microscopy (SEM), Cheng et al.2 observed grain cracking in the electrode material intensifying with successive cycles. They compared the NMC811 after 14 cycles for a cutoff potential of 4.1 vs. Li+/Li and 4.7 vs. Li+/Li. G anty et al.3 used in situ XRD studies to monitor changes in NMC811 during charge and discharge cycling, with particular emphasis on changes in the a and c unit cell parameters and the appearance of the H2 hexagonal phase during charging (significantly reduced lithium content in the structure). Also, Raman spectroscopy can be used to make comparisons of the changes occurring in the active material during its lithiation and delithiation. Flores et al.4 study layered active materials using Raman spectroscopy and was able to see significant changes in the structure, such as showing that the oxidation of Ni2+/Ni3+ ↔ Ni3+/Ni4+ is gradual.However, in situ techniques have limitations in combining various methods to test the same sample. To facilitate the use of several techniques, ex situ testing can be employed. In this research, nickel-rich NMC samples were analyzed using a combination of ex situ XRD, SEM, and Raman spectroscopy. This approach provides more information on the phenomena occurring during cell operation, allowing for better understanding of the problems that need to be addressed. SEM images can identify the presence of structural irregularities that can affect the material's electrochemical performance, including defects and cracks. XRD provides overall information on phases present in the bulk sample, their grain size, and crystallographic parameters, and allows for thorough Raman analysis. Ex situ Raman spectroscopy enables experiments to be carried out at a specific location, increases the reliability of tests, and provides detailed information on phase transitions and the causes of capacity drop during the cell operation. Together, these techniques provide valuable insights into the structural changes that occur in NMC622 material during lithiation and delithiation processes. By analyzing the crystal structure, and surface morphology of the cathode material before and after cycling, these techniques can help identify the mechanisms of degradation and suggest strategies for improving battery performance and lifespan. A detailed analysis will be presented during the conference. This work was funded by the National Center for Science in Poland through the Sonata BIS 11 programme (No. UMO-2021/42/E/ST5/00390).Reference: Zhang, S. S. Problems and their origins of Ni-rich layered oxide cathode materials. Energy Storage Mater 24, 247–254 (2020). Cheng, X. et al. Real-Time Observation of Chemomechanical Breakdown in a Layered Nickel-Rich Oxide Cathode Realized by in situ Scanning Electron Microscopy. ACS Energy Lett 6, (2021). Ghanty, C. et al. Li+-Ion Extraction/Insertion of Ni-Rich Li1+x(NiyCozMnz)wO2 (0.005<x<0.03; y: Z=8:1, w≈1) Electrodes: In situ XRD and Raman Spectroscopy Study. ChemElectroChem 2, (2015). Flores, E. et al. Cation Ordering and Redox Chemistry of Layered Ni-Rich Li xNi1-2 yCo yMn yO2: An Operando Raman Spectroscopy Study. Chemistry of Materials 32, (2020).

Microstructural changes in the irradiated and osteoradionecrotic bone: a SEM study

ABSTRACT Radiation exposure is a major health concern due to bone involvement including mandible, causing deleterious effects on bone metabolism, and healing with an increasing risk of infection and osteoradionecrosis. This study aims to investigate the radiotherapy-induced microstructural changes in the human mandible by scanning electron microscopy (SEM). Mandibular cortical bone biopsies were obtained from control, irradiated, and patients with osteoradionecrosis (ORN). Bone samples were prepared for light microscopy and SEM. The SEM images were analyzed for the number of osteons, number of Haversian canal (HC), diameter of osteon (D.O), the diameter of HC (D.HC), osteonal wall thickness (O.W.Th), number of osteocytes, and number of osteocytic dendrites. The number of osteons, D.O, D.HC, O.W.Th, the number of osteocytes, and osteocytic dendrites were significantly decreased in both irradiated and ORN compared to controls (p < .05). The number of HCs decreased in irradiated and ORN bone compared to the control group. However, this was statistically not significant. The deleterious effect of radiation continues gradually altering the bone quality, structure, cellularity, and vascularity in the long term (>5 years mean radiation biopsy interval). The underlying microscopic damage in bone increases its susceptibility and contributes further to radiation-induced bone changes or even ORN.

Complex magnetic behaviour and photocatalytic response in narrowed band gap NiO nanoparticles synthesized by novel Lepidagathis ananthapuramensis leaf extract

The present work focussed on the detailed investigation on structural, morphological, optical, photocatalytic, and magnetic properties of NiO nanoparticles (NPs) derived by a novel Lepidagathis ananthapuramensis leaf extract. The structural information using X-ray powder diffraction and Raman spectroscopy method indicates a single phase NiO hexagonal crystal structure for the sample calcined at ≥ 600 °C. Field emission scanning electron microscopy and high-resolution transmission electron microscopy studies noticed the various morphologies. UV–Visible, photoluminescence, and X-ray photoelectron spectroscopy confirmed the presence of both Ni2+ and Ni3+ ions with the narrowed band gap. Thorough magnetic studies indicate the existence of antiferromagnetic, ferromagnetic and superparamagnetic nature of NiO NPs. The photocatalytic activity of NiO NPs for the photocatalytic degradation of methylene blue dye in the presence of sunlight showed considerable results. This study can help us to deliver the wide range of properties which can be utilised in the field of magnetism and photocatalysis.

From macro to micro: A close-up look at Hydrangea luteovenosa and Hydrangea serrata.

Understanding the anatomical traits of the foliar epidermis is essential for making precise species identification and categorization. In this study, scanning electron microscopy (SEM) was used to examine the taxonomically significant foliar epidermal traits of Hydrangea luteovenosa and H. serrata. The qualitative and quantitative traits observed included the epidermal cell form, cuticle presence, trichome morphology, stomatal type, and guard cell features. H. serrata had a thin and smooth cuticle, and epidermal cells organized compactly into cubic or hexagonal shapes. The stomata were of the anomocytic type and dispersed, while the trichomes were straightforward, unbranched, and distributed sparsely. The guard cells had distinct cell walls and a kidney-shaped morphology. These crucial traits for taxonomy were in line with an epidermis composed of three to five layers. Similar polygonal epidermal cells with a compact arrangement were observed in H. luteovenosa, together with a thin and smooth cuticle. The stomata were anomocytic and dispersed, while the trichomes were straightforward, unbranched, and sparsely distributed. The guard cells have distinct cell walls and a kidney-shaped morphology. The traits were indicative of an epidermal structure with three to five layers. These traits helped correctly identify and categorize these two species of Hydrangea. In addition to assisting in the taxonomic classification of these species and advancing knowledge of their ecological and evolutionary links, the SEM study provided insightful information into the structural variety of these species. RESEARCH HIGHLIGHTS: Microscopic characteristics of H. luteovenosa and H. serrata Understanding the anatomical traits of the foliar epidermis is essential for precise species identification and categorization.

Exploration of a wide bandgap semiconducting supramolecular Mg(II)-metallohydrogel derived from an aliphatic amine: a robust resistive switching framework for brain-inspired computing

A rapid metallohydrogelation strategy has been developed of magnesium(II)-ion using trimethylamine as a low molecular weight gelator in water medium at room temperature. The mechanical property of the synthesized metallohydrogel material is established through the rheological analysis. The nano-rose like morphological patterns of Mg(II)-metallohydrogel are characterized through field emission scanning electron microscopic study. The energy dispersive X-ray elemental mapping analysis confirms the primary gel forming elements of Mg(II)-metallohydrogel. The possible metallohydrogel formation strategy has been analyzed through FT-IR spectroscopic study. In this work, magnesium(II) metallohydrogel (Mg@TMA) based metal–semiconductor-metal structures have been developed and charge transport behaviour is studied. Here, it is confirmed that the magnesium(II) metallohydrogel (Mg@TMA) based resistive random access memory (RRAM) device is showing bipolar resistive switching behaviour at room temperature. We have also explored the mechanism of resistive switching behaviour using the formation (rupture) of conductive filaments between the metal electrodes. This RRAM devices exhibit excellent switching endurance over 10,000 switching cycles with a large ON/OFF ratio (~ 100). The easy fabrication techniques, robust resistive switching behaviour and stability of the present system makes these structures preferred candidate for applications in non-volatile memory design, neuromorphic computing, flexible electronics and optoelectronics etc.

Effect of number of sol-layer on structural, optical, morphological, and compositional properties of HfO2 films

Using sol-gel based spin coating HfO2 thin films were prepared on quartz substrates. The effect of sol-layer thickness on structural, optical, morphological and compositional properties was investigated. The structural studies done using X-Ray Diffraction (XRD) and Raman confirm the presence of a polycrystalline monoclinic phase of HfO2. Atomic Force Microscopy (AFM) and Field Emission Scanning Electron Microscope (FESEM) studies reveal a uniform distribution of grains on the substrates. An increment in Hf is confirmed from Energy Dispersive Spectroscopy (EDS) with respect to the number of sol-layers. From XPS results existence of oxygen vacancies and the formation of HfO2 was noted. These results suggest that tailoring the number of sol-layers plays a crucial role in modifying the properties of HfO2 based thin films.

Fatigue crack growth rate and propagation mechanisms of SiC particle reinforced Al alloy matrix composites

PurposeThis study aims to investigate the fatigue crack propagation behavior of SiC particle-reinforced 2124 Al alloy composites under constant amplitude axial loading at a stress ratio of R = 0.1. For this purpose, it is performed experiments and comparatively analyze the results by producing 5, 10, 15 Vol.% SiCp-reinforced composites and unreinforced 2124 Al alloy billets with powder metallurgy (PM) production technique.Design/methodology/approachWith the PM production technique, SiCp-reinforced composite and unreinforced 2124 Al alloy billets were produced at 5%, 10%, 15% volume ratios. After the produced billets were extruded and 5 mm thick plates were formed, tensile and fatigue crack propagation compact tensile (CT) samples were prepared. Optical microscope examinations were carried out to determine the microstructural properties of billet and samples. To determine the SiC particle–matrix interactions due to the composite microstructure, unlike the Al alloy, which affects the crack initiation life and crack propagation rate, detailed scanning electron microscopy (SEM) studies have been carried out.FindingsOptical microscope examinations for the determination of the microstructural properties of billet and samples showed that although SiC particles were rarely clustered in the Al alloy matrix, they were generally homogeneously dispersed. Fatigue crack propagation rates were determined experimentally. While the highest crack initiation resistance was achieved at 5% SiC volume ratio, the slowest crack propagation rate in the stable crack propagation region was found in the unreinforced 2124 Al alloy. At volume ratios greater than 5%, the number of crack initiation cycles decreases and the propagation rate increases.Originality/valueAs a requirement of damage tolerance design, the fatigue crack propagation rate and fatigue behavior of materials to be used in high-tech vehicles such as aircraft structural parts should be well characterized. Therefore, safer use of these materials in critical structural parts becomes widespread. In this study, besides measuring fatigue crack propagation rates, the mechanisms causing crack acceleration or deceleration were determined by applying detailed SEM examinations.

Deciphering the Nature of an Overlooked Rate‐Limiting Interphase in High‐Voltage LiNi0.5Mn1.5O4 Cathodes: A Combined Electrochemical Impedance, Scanning Electron Microscopy and Secondary Ion Mass Spectrometry Study

AbstractHigh‐voltage cathode active materials, such as LiNi0.5Mn1.5O4 (LNMO), are of major interest for the development of high‐energy lithium‐ion batteries. However, it has been reported that composite cathodes based on high‐voltage active materials suffer from high impedances and low rate capabilities. The origin of the high impedances has not yet been clarified. Here, we use a combination of electrochemical impedance spectroscopy (EIS), focused ion beam/scanning electron microscopy/energy‐dispersive X‐ray spectroscopy (FIB/SEM/EDX) and time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) for showing that in the case of LNMO‐based cathodes, a major part of the cathode impedance is related to the formation of a passivating interphase on the Al current collector. Remarkably, the impedance of this interphase can be mitigated by the targeted formation of a distinct passivating interphase, namely on the surface of the LNMO particles. The interplay between these interphases is discussed.

Preparation, characterization, and in vitro evaluation of the anticancer activity of Ce3+ doped CuFe2O4 spinel nanoparticles in MCF-7 cell lines

In the present study, we successfully prepared nanoparticles of Ce-doped Copper ferrite, CuCexFe2-xO4(x = 0.00, 0.03, and 0.05), in the nanoscale using the chemical co-precipitation technique. The structure, composition, optical properties, and morphological information of the obtained ferrite nanoparticles (NPs) were analyzed by making use of powder X-ray diffraction (PXRD) pattern, Field Emission Scanning Electron Microscopic (FE-SEM) studies, Fourier Transform Infrared Spectroscopic (FT-IR) analysis, and Energy-dispersive X-Ray Spectroscopy (EDS), and the UV–Vis-NIR Spectroscopy. The cytotoxicity of CuCexFe2-xO4 nanoparticles (NPs) on the MCF-7 breast cancer cell line was evaluated using the MTT assay. The NPs exhibited dose-dependent cytotoxicity, with lower concentrations (<25 µg/mL) being safe and biocompatible, while higher concentrations reduced cell viability and disrupted L929 fibroblast cell lines. Double staining and flow cytometry experiments revealed that apoptosis is one of the mechanisms by which CuCexFe2-xO4 NPs induce cytotoxicity in MCF-7 cells. An increase in reactive oxygen species (ROS) was found in the presence NPs. To harness the full potential of this nanoparticle formulation, it is recommended that future investigations encompass a wide range of in vitro and in vivo models. These subsequent studies will significantly contribute to the expanding body of knowledge concerning the synthesis of composite nanoparticle formulations for use as anticancer agents.

The development of chrome free chestnut and Tetrakis Hydroxymethyl Phosphonium Sulfate based Eco-benign combination tanning system

The replacement of the conventional chromium tanning system with an eco-benign tanning systems has received great attention owing to stringent environmental regulations. In this specific study, a chrome-free combination tanning system based on chestnut and tetrakis (hydroxymethyl) phosphonium sulfate (THPS) was developed and presented as an effective alternative cleaner tanning technology. Processing of the tanning trials were carried out varying the percentages of chestnut as a tannage, followed by THPS as a re-tannage for process optimization. The leathers obtained were characterized for their thermal stability, grain surface properties using a scanning electron microscope, physical strength characteristics, comfort, and organoleptic properties. Finally, the environmental impact of the tanning systems was assessed through the comparative analysis of their spent liquors. The chestnut-THPS combination system tanned leathers using 20 % chestnut followed by 2 % THPS resulted in maximum shrinkage temperature of 95OC. The hydrothermal stability of the leathers tanned using this combination tanning system were found to be better than those tanned using chestnut and THPS tanning systems alone, respectively. The strength and comfort properties of the leathers produced using the developed combination tanning system were found to be on par with or better than those of conventionally tanned leathers, and the scanning electron microscopic study depicted that the grain surface of the leathers produced were observed to be free of surface deposition. The environmental impact assessment showed that the combination tanning system used resulted in a significant reduction in TS, TDS, TSS, and BOD in the wastewater. This research article has attempted and established the use of chestnut-THPS-based combination tanning systems as an effective, eco-friendly alternative tanning process technology.