X-ray Diffraction Research Articles

Определение литологического состава осадочных пород для построения объемной модели по данным ГИС

The features of the lithological composition of productive sediments and their consideration in the petrophysical modeling of a volumetric model based on a GIS complex are considered. It is noted that on the basis of X-ray spectral and granulometric analysis, it is possible to obtain reliable information about the structure, texture, component and mineral composition in order to clarify the petrophysical characteristics of the rocks under study. Using the example of two hydrocarbon deposits “K” and “N” the results of determining the lithological composition of sedimentary rocks from core from different age terrigenous deposits are discussed in order to build a petrophysical model of the entire well section, taking into account the areas of lack of information from direct studies (sludge and core). Electron microscopy and X-ray diffraction analysis are used to study finely dispersed (clay, siliceous, carbonate, etc.) rocks, which are especially important for accurate diagnosis of the mineral composition of rocks. In addition to the features of the geological structure of the deposit, the quantity and quality of the initial information largely determine the methods of constructing the model and the results obtained. The results of X-ray spectral analysis made it possible to determine the composition of chemical elements and the amount of each element in the sample. Information about the mineral composition of rocks and the lithological differences identified at the first stage are distributed to the part of the section where there is no or insufficient information on the core or sludge. The information obtained on the lithological composition of sediments gives the most complete picture of the geological structure of the section opened by the well and is further used as the basis of a volumetric model based on the data of geophysical surveys of GIS wells.

Phosphetene-Based Polyaromatics: Structure-Property Relationships and Chiroptical Tuning.

We describe the synthesis of π-extended phosphetene rings (4-member P-rings) flanked with PAH systems of various topologies. These compounds are fully characterized including X-ray diffraction. The impact of both the polyaromatic platform and the P-ring on the structure, and the optical and redox properties are investigated both experimentally and theoretically. Although neither the P centre nor the 4-membered ring significantly takes part in the HOMO or LUMO orbitals, both structural features have an important modulating role in distorting the symmetry of the orbitals, leading to chiroptical properties. The stereogenic P-atom is used as a remote chiral perturbator to induce circularly polarized luminescence of the polyaromatic system. The dissymmetry factor is highly dependent on the polyaromatic topology, as supported by theoretical calculations.

Pharmaceutical effluent degradation using hydrogen peroxide-supported zerovalent iron nanoparticles catalyst

Pharmaceutical effluents generated during drugs production and application are often times released into the water systems with little or no treatment, which could pose potential danger to the ecosystem. Advanced oxidation processes for organic pollutants treatment have gained wide consideration due to their effectiveness. In this work, hydrogen peroxide (H2O2) and hydrogen peroxide-supported nano zerovalent iron (H2O2@nZVIs) were deployed to study pharmaceutical effluents (PE) degradation via batch experiments, under various reaction time, (H2O2) and (H2O2@nZVIs) concentrations, pH, PE concentration, and temperature. The nZVIs was prepared from the green synthesis of Vernonia amygdalina leaf extract and characterized using different analytical tools such as Fourier Transform-Infrared Spectroscopy (FT-IR), Gas Chromatography Mass Spectroscopy (GC-MS), Scanning Electron Microscopy (SEM), and X-Ray Diffraction Spectroscopy (XRD). The FT-IR results showed the presence of -C = O, -NH, -OH, -C = C and, -C-O functional groups, SEM report showed that the morphology of the nZVIs is round in shape, while GC-MS revealed the presence of several phytochemicals. When the concentration of the effluent was increased from 10 to 30 ml, the percentage decolourization decreased from 74.74 to 51.96% and from 80.36 to 54.38% for H2O2 and H2O2@nZVI respectively, whereas when the contact time was increased from 10 to 60 min, the percentage decolourization rose from 70.39 to 83.49% for H2O2 and from 85.19 to 89.73% when H2O2@nZVI was used. When the effect of pH was assessed, it was observed that on increasing the pH from 2 to 10, the percentage decolourization rose from 74.5 to 80.25% for H2O2, however, with H2O2@nZVI, the percentage decolourization decreased from 81.50 to 68%. Maximum percentage decolourization of 57.10% and 94.56% for H2O2 and H2O2@nZVI was achieved at catalyst volume of 25 ml. For all the parameters tested, the H2O2@nZVIs performed much better indicating that the nZVIs enhanced the decolourization ability of the H2O2. The kinetic results showed that the decolorization of pharmaceutical effluent by both catalysts fitted very well with the second-order model, while thermodynamic properties of enthalpy change were found to be 10.025 and 27.005 kJ/mol/K for H2O2 and H2O2@nZVIs respectively suggesting that the oxidation process is endothermic in nature. This technique employed in using hydrogen peroxide-supported zero valent iron, proved to be highly efficient not only for pharmaceutical effluent degradation but also in the elimination of lead from the effluent.

Melanin-intercalated layered double hydroxide LDH/MNP as a stable photothermal agent

Melanin nanoparticles (MNPs) are a type of electronegative compound that can be used as photothermal agent for cancer treatment. Nevertheless, the agglomeration of MNP, which is one of the limitations in practice, contributes to the instability of MNP. Pristine layered double hydroxide (LDH), as a kind of positive inorganic material when there exist no other cargo between its layers, can accommodate electronegative molecules between its layers to endow them with stable properties. Hence, in this study, electronegative MNP was intercalated into LDH lamellas via ion-exchange method to obtain the stable original photothermal agent LDH/MNP, solving the tough problem of MNP’s agglomeration. The surface morphology, X-ray diffraction and fourier transform infrared spectra affirmed the successful intercalation of MNP between LDH lamellas. The Z-average particle sizes of LDH/MNP on day 0, 7 and 14 were measured as 221.8 nm, 227.6 nm and 230.5 nm without obvious fluctuation, while the particle sizes of MNP went through dramatic enlargement from 105.8 nm (day 0) to 856.1 nm (day 7), indicating the better stability of LDH/MNP than MNP. The typical polymer dispersity index (PDI) values on day 0, 7 and 14 verified the better stability of LDH/MNP, too. Photothermal properties of LDH/MNP were assessed and the results ensured the representative photothermal properties of LDH/MNP. The fine cytocompatibility of LDH/MNP was verified via cytotoxicity test. Results confirmed that the agglomeration of MNP disappeared after its intercalation into LDH and LDH/MNP possessed fine stability as well as typical photothermal property. The intercalation of MNP into LDH gave the photothermal agent MNP a promising way for its better stability and long-term availability in photothermal treatment.

Development of Chitosan-Coated Graphene Oxide and Iron Oxide Nanocomposites for Targeted Delivery of Camptothecin to Liver Cancer Cells.

Innovative drug delivery platforms for selective, regulated, and sustained release of anticancer drugs are crucial in cancer treatment. This study presents nanoparticles developed from chitosan (CS), graphene oxide (GO), and magnetite (Fe3O4), and their nanocomposites, to enhance the loading and release efficiency of camptothecin (CPT). Nanostructures were characterized using imaging microscopy, FT-IR, and X-ray diffraction, with an average crystallite size of 5.5 nm. Camptothecin binding proportions were 70% for CS, 81% for CS@Fe3O4, 58% for CS@GO, and 74% for CS@GO/Fe3O4. At pH 5.0, CPT release ratios were 87%, 80%, 88%, and 90%, respectively, and at pH 7.4, 84%, 72%, 89%, and 87%. Cytotoxicity was assessed using the MTT assay against HepG2 and SMMC-7721 cancer cells. CPT-CS@GO/Fe3O4 exhibited the highest survival at 5 µM and 12.5 µM concentrations, indicating it as the most effective nanocarrier for camptothecin delivery. The study demonstrates CS@GO/Fe3O4's potential as a superior drug delivery system.

Two Distinct Charge Orders in Infinite-layer PrNiO2+δ revealed by Resonant X-ray Diffraction

Abstract The study of infinite-layer nickelates has unveiled a broken translation symmetry, which has sparked significant interest in its root, its relationship to superconductivity, and its comparison to charge order in cuprates. In this study, resonant X-ray scattering measurements were performed on thin films of infinite-layer PrNiO2+δ. The results showed significant differences in the superlattice reflection at the Ni L 3 absorption edge compared to that at the Pr M 5 resonance in their dependence on energy, temperature, and local symmetry. These differences point to two distinct charge orders, although they share the same in-plane wavevectors. It is suggested that these dissimilarities could be linked to the excess oxygen dopants, given that the resonant reflections were observed in an incompletely reduced PrNiO2+δ film. Furthermore, azimuthal analysis indicates that the oxygen ligands likely play a crucial role in the charge modulation revealed at the Ni L 3 resonance.

Stability Assessment in Aqueous and Organic Solvents of Metal-Organic Framework PCN 333 Nanoparticles through a Combination of Physicochemical Characterization and Computational Simulations.

Mesoporous metal-organic frameworks (MOFs) have been recognized as powerful platforms for drug delivery, especially for biomolecules. Unfortunately, the application of MOFs is restricted due to their relatively poor stability in aqueous media, which is crucial for drug delivery applications. An exception is the porous coordination network (PCN)-series (e.g., PCN-333 and PCN-332), a series of MOFs with outstanding stability in aqueous media at the pH range from 3 to 9. In this study, we fabricate PCN-333 nanoparticles (nPCN) and investigate their stability in different solvents, including water, ethanol, and methanol. Surprisingly, the experimental characterizations in terms of X-ray diffraction, Brunauer-Emmett-Teller (BET), and scanning electron microscopy demonstrated that nPCN is not as stable in water as previously reported. Specifically, the crystalline structure of nPCN lost its typical octahedral shape and even decomposed into an irregular amorphous form when exposed to water for only 2 h, but not when ethanol and methanol were used. Meanwhile, the porosity of nPCN substantially diminished while being exposed to water, as demonstrated by the BET measurement. With the assistance of computational simulations, the mechanism behind the collapse of PCN-333 is illuminated. By molecular dynamics simulation and umbrella sampling, we elucidate that the degradation of PCN-333 occurs by hydrolysis, wherein polar solvent molecules initiate the attack and subsequent breakage of the metal-ligand reversible coordination bonds.

Biosynthesis of CuO nanoparticle using leaf extracts of Ocimum lamiifolium Hochst. ex Benth and Withana somnifera (L) Dunal for antibacterial activity

Nanotechnology is becoming a promise for scientific advancement nowadays in areas like medicine, consumer products, energy, materials, and manufacturing. Copper oxide nanoparticles (CuO NPs) were synthesized using Ocimum lamiifolium Hochst. ex Benth and Withana somnifera (L) Dunal leaf extract via green synthetic pathway. The leaf of O. lamiifolium and W. somnifera were known to have strong antibiotic and antioxidant properties arising due to the presence of various secondary metabolites, including, flavonoids, alkaloids, saponins, tannins, cardiac glycosides, and phenolic compounds which serve as reducing, stabilizing, and capping agents for the CuO-Nanoparticles (NPs) synthesized. The biosynthesized CuO NPs were characterized based on Fourier transform infrared spectroscopy, X-ray diffraction spectroscopy, and scanning electron microscopy. O. lamiifolium and W. somnifera leaf extract mediated synthesis could produce CuO NPs with average crystallite size of 15 nm and 19 nm, respectively. The biosynthesized CuO-NPs were further examined for antibacterial activity with Gram-positive (S. aureus) and Gram-negative bacteria (E. coli and P. aeruginosa). The GZDK-CuO NPs synthesized using W. somnifera leaf extract inhibited the growth of E. coli. and P. aeruginosa largely in comparison to S. aureus. Whereas the DMAZ-CuO NPs synthesized with the help of O. lamiifolium leaf extract showed higher bacterial inhibition on E. coli compared to S. aureus and P. aeruginosa. The minimum inhibitory concentration (MIC) values of both types of NPs are also assessed on all three pathogens. The newly biosynthesized nanoparticles, thus, were found to be optional materials for inhibiting the growth of drug- resistant bacterial pathogens.

A grey relational analysis of the micro arc oxidation process parameters and their effects on Ti-6Al-7Nb coating performance and corrosion resistance for biomedical uses

Abstract In current investigation micro arc oxidation of Ti6Al7Nb alloy was done to improve its surface properties and corrosion resistance. Mixture of Na2SiO3, Na3PO412H2O and KOH is used as electrolyte. MAO treated Ti6Al7Nb specimens were examined using x-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM) to examine their morphology and phase composition. It was observed that electrolyte composition is simultaneously included in the growing oxide layer during MAO process. From electrochemical study it was found that corrosion resistance of the Ti6Al7Nb increases during EIS testing in 0.9% NaCl solution. It was found that frequency, duty cycle, current and processing time effect the surface roughness, thickness, hardness and corrosion resistance of coating. Out of above mention parameters frequency and duty cycle has major impact on performance parameters. The objective of current investigation is to find out effects MAO process parameters on coating performance parameters such as coating thickness, hardness, surface roughness and corrosion resistance. At duty cycle of 50%, frequency 500 Hz, current 300 mA and processing duration 7.5 min, highest coating thickness 32.96 μm and surface roughness 3.3680 μm was obtained. Process parameters have the influence on pore size, biggest average pore size 3.8519 μm was obtained at duty cycle of 50%, frequency 500 Hz, current 300 mA and processing duration 7.5 min. Grey relational analysis is done to determine which process variable has the most influence on performance parameters. From grey relational analysis technique, it was observed that duty cycle 50%, frequency 500 Hz, current 300 mA, and processing time 7.5 min are ideal process parameters for higher coating thickness, hardness, surface roughness and better corrosion resistance. From grey relation analysis it was also found that frequency has most significant impact on performance parameters after that duty cycle, then current and at last processing time.

Influence of temperature on the cathodic polarization behavior and calcareous deposit properties of X65 steel in sea water

Purpose This paper aims to investigate how cathodic polarization behavior significantly affects the selection of cathodic protection parameters and the effectiveness of protecting underwater metal structures. Factors such as water depth and operating conditions impact seawater temperature, making it crucial to understand the effects of temperature on cathodic protection parameters for underwater pipelines. Design/methodology/approach In this paper, potentiostatic polarization was carried out by three-electrode method, and morphology, X-ray diffraction and electrochemical analysis. Findings It was determined that the stable current densities at the minimum negative potential (−0.8 VSSC) for pipeline steel varied at different temperatures: 7°C, room temperature and 60°C. The cathodic protection potential corresponding to the lowest stable current density was observed to be −1.0 VSSC at 7°C and −0.95 VSSC at room temperature and 60°C. Originality/value This study elucidates the mechanisms by which different temperatures affect the protective performance of calcareous deposits and current densities.

Dark current in FTO/CZTS interface: a comprehensive comparison of practical Vs theoretical approach using SCAPS-1D

This study investigates the deposition of Cu2ZnSnS4 (CZTS) thin films on fluorine-doped tin oxide (FTO) and soda-lime glass (SLG) substrates using radio frequency (RF) sputtering at varying temperatures. A comprehensive characterization employing multiple analytical techniques was conducted. X-ray diffraction (XRD) analyses confirmed the amorphous nature of CZTS films being deposited up to 200 °C, while higher temperatures promoted increased crystallinity, with the presence of (112) and (220) planes observed at 300 °C and 400 °C. Rietveld refinement using Profex software revealed an increase in crystallite size with deposition temperature for films grown at 300 °C and 400 °C. Optical characterization through UV–vis spectroscopy unveiled a decrease in band gap energy with increasing deposition temperature, while the Urbach energy, associated with defects and imperfections, exhibited an inverse relationship with band gap and temperature. Experimental current–voltage (I-V) measurements using a Keithley source meter showed variations in the ideality factor with deposition temperature. SCAPS-1D simulations were performed to model the FTO/CZTS interface, incorporating experimental parameters. The simulated I-V behavior demonstrated a transition from recombination to diffusion-dominated current above 1.3 V forward bias. Simulations yielded higher ideality factors due to increased contributions from recombination and diffusion currents. Overall, this study provides insights into the growth, structural, optical, and electrical properties of CZTS thin films deposited by RF sputtering, enabling a comprehensive understanding of the FTO/CZTS heterojunction characteristics and their dependence on deposition temperature.

Single-Crystalline 3D Covalent Organic Frameworks with Exceptionally High Specific Surface Areas and Gas Storage Capacities.

Single-crystalline covalent organic frameworks (COFs) are highly desirable toward understanding their pore chemistry and functions. Herein, two 50-100 μm single-crystalline three-dimensional (3D) COFs, TAM-TFPB-COF and TAPB-TFS-COF, were prepared from the condensation of 4,4',4″,4‴-methanetetrayltetraaniline (TAM) with 3,3',5,5'-tetrakis(4-formylphenyl)bimesityl (TFPB) and 3,3',5,5'-tetrakis(4-aminophenyl)bimesityl (TAPB) with 4,4',4″,4‴-silanetetrayltetrabenzaldehyde (TFS), respectively, in 1,4-dioxane under the catalysis of acetic acid. Single-crystal 3D electron diffraction reveals the triply interpenetrated dia-b networks of TAM-TFPB-COF with atom resolution, while the isostructure of TAPB-TFS-COF was disclosed by synchrotron single-crystal X-ray diffraction and synchrotron powder X-ray diffraction with Le Bail refinements. The nitrogen sorption measurements at 77 K disclose the microporosity nature of both activated COFs with their exceptionally high Brunauer-Emmett-Teller surface areas of 3533 and 4107 m2 g-1, representing the thus far record high specific surface area among imine-bonded COFs. This enables the activated COFs to exhibit also the record high methane uptake capacities up to 28.9 wt % (570 cm3 g-1) at 25 °C and 200 bar among all COFs reported thus far. This work not only presents the structures of two single-crystalline COFs with exceptional microporosity but also provides an example of atom engineering to adjust permanent microporous structures for methane storage.

Fabrication and Characterization of Biopolymers Using Polyvinyl Alcohol and Cardanol-Based Polyols

Biodegradable polymers are getting attention as renewable alternatives to petroleum-based plastics due to their environmental benefits. However, improving their physical properties remains challenging. In this work, biodegradable biopolymers (PVA-PCD) were fabricated by chemically crosslinking petroleum-based polyvinyl alcohol (PVA) with biomass-derived cardanol-based polyols (PCD). Biopolymers were characterized using various techniques, including Fourier-transform infrared (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and swelling tests. Cardanol, the raw material, was converted into polyols via epoxidation followed by hydroxylation. FT-IR analysis confirmed that PVA-PCD biopolymers were crosslinked between the hydroxyl groups of PVA and PCD and the aldehydes of crosslinker glutaraldehyde (GLU), accompanied by the formation of acetal groups with ether bridges. XRD showed that the crystallinity of crosslinked polymers decreased, indicating that crosslinking occurs disorderly. TGA exhibited that GLU significantly improved the thermal stabilities of PVA and PCD-PVA polymers, as evidenced by increased decomposition temperatures. On the other hand, the effect of PVA/PCD ratios was minor on biopolymers’ thermal stabilities. Swelling tests revealed that increased crosslinking density decreased the swelling ratio, suggesting that PVA-PCD biopolymers become more hydrophobic with high brittleness, high strength, and low swelling capacity. In summary, this study demonstrates that PVA-PCD biopolymers fabricated from biomass-derived materials have potential for various applications, such as biodegradable materials and sustainable packaging.

Two Organic-Inorganic Hybrid Manganese Bromides with Highly Efficient Emission toward White LEDs.

Organic-inorganic metal halides have attracted great attention due to their tunable structural and spectroscopic properties. Here, two organic-inorganic hybrid manganese bromides, (TEMA)2MnBr4 (TEMA = triethylmethylammonium) and (TEBA)2MnBr4 (TEBA = benzyltriethylammonium), are synthesized using the evaporation crystallization method. Following a heat-induced phase transition at 363 K, the structure and optical properties of (TEMA)2MnBr4 change but return to their initial state upon cooling to room temperature, as confirmed by X-ray diffraction, photoluminescence (PL), and Raman spectra. Meanwhile, (TEBA)2MnBr4, with a larger Mn-Mn distance, exhibits a higher photoluminescence quantum yield of 98.1% and greater thermal quenching temperature. However, due to the poorer thermal stability of the organic cation, the crystal melts at 400 K, leading to fluorescence quenching. White LEDs based on (TEMA)2MnBr4 and (TEBA)2MnBr4 are successfully fabricated with color rendering indices of 97.4 and 97.2, respectively. The investigation provides deep insights into the structural and optical properties of (TEMA)2MnBr4 and (TEBA)2MnBr4, advancing research for LED display design by tuning organic cations.

Hydrogen Bond Integration in Potato Microstructure: Effects of Water Removal, Thermal Treatment, and Cooking Techniques

Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Scanning electron microscopy (SEM) were used to study the effects of heat treatments and water removal by freeze-drying after different time intervals (6, 12, 24, 48, and 72 h) on the molecular structure of potato tubers. SEM images show structural differences between raw (RP), microwaved (MP), and boiled potato (BP). MP showed a cracked structure. BP was able to re-associate into a granule-like structure after 6 h of freeze-dying, whereas RP had dried granules within a porous matrix after 24 h of freeze-drying. These results are consistent with the moisture content and FTIR results for MP and BP, which demonstrated dried spectra after 6 h of freeze-drying and relatively coincided with RP results after 24 h of freeze-drying. Additionally, three types of hydrogen bonds have been characterized between water and starch, and the prevalence of water very weakly bound to starch has also been detected. The relative crystallinity (RC) was increased by thermal treatment, whereby microwaving recorded the highest value. A comparison of the FTIR and XRD results indicated that freeze-drying treatment overcomes heat effects to generate an integral starch molecule.

Sol–Gel Derived Alumina Particles for the Reinforcement of Copper Films on Brass Substrates

The aim of this study is to provide tailored alumina particles suitable for reinforcing the metal matrix film. The sol–gel method was chosen to prepare particles of submicron size and to control crystal structure by calcination. In this study, copper-based metal matrix composite (MMC) films are developed on brass substrates with different electrodeposition times and alumina concentrations. Scanning electron microscopy (FE-SEM) with energy-dispersive spectroscopy (EDS), TEM, and X-ray diffraction (XRD) were used to characterize the reinforcing phase. The MMC Cu-Al2O3 films were synthesized electrochemically using the co-electrodeposition method. Microstructural and topographical analyses of pure (alumina-free) Cu films and the Cu films with incorporated Al2O3 particles were performed using FE-SEM/EDS and AFM, respectively. Hardness and adhesion resistance were investigated using the Vickers microindentation test and evaluated by applying the Chen–Gao (C-G) mathematical model. The sessile drop method was used for measuring contact angles for water. The microhardness and adhesion of the MMC Cu-Al2O3 films are improved when Al2O3 is added. The concentration of alumina particles in the electrolyte correlates with an increase in absolute film hardness in the way that 1.0 wt.% of alumina in electrolytes results in a 9.96% increase compared to the pure copper film, and the improvement is maximal in the film obtained from electrolytes containing 3.0 wt.% alumina giving the film 2.128 GPa, a 134% hardness value of that of the pure copper film. The surface roughness of the MMC film increased from 2.8 to 6.9 times compared to the Cu film without particles. The decrease in the water contact angle of Cu films with incorporated alumina particles relative to the pure Cu films was from 84.94° to 58.78°.

Synthesis and Properties of Highly Tilted Antiferroelectric Liquid Crystalline (R) Enantiomers

This work reports the synthesis method and various properties of four rod-like antiferroelectric (R) laterally substituted enantiomers, with or without fluorine atoms used as substituents in the benzene ring. The influence of fluorine substitution on the mesophase temperature range was determined. The synthesized compounds are three-ring rod-like smectics with a chiral center based on (R)-(−)-2-octanol. Their chemical and optical purity was checked using high-performance liquid chromatography (HPLC). Two newly synthesized enantiomers and three previously reported (R) enantiomers were used to formulate two antiferroelectric mixtures. The mesomorphic behavior was characterized by polarizing optical microscopy, differential scanning calorimetry, and X-ray diffraction (XRD). The helical pitch and tilt angle measurements were done using the selective light reflection phenomenon and the electro-optical method, respectively. All the enantiomers exhibit a wide temperature range of the antiferroelectric phase, with a high tilt angle. Furthermore, the enantiomer with lateral fluorine substitution in the ortho position has a very long helical pitch (more than 2.0 µm), relatively low enthalpy of melting point, and a tilt angle close to 45 degrees. The designed (R) enantiomers can be useful for formulating eutectic mixtures for further use in various devices, including photonics and optoelectronics.

Corrosion Behavior of 700L Automotive Beam Steel in Marine Atmospheric Environment

The marine atmospheric corrosion behavior of 700L high-strength automotive beam steel exposed for 36 months was investigated by scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and electrochemical technology. The corrosion kinetics of 700L steel followed the exponential function: D = 4.85t1.23. The rust layers were mainly composited of γ-FeOOH, α-FeOOH, γ-Fe2O3, and Fe3O4, regardless of the exposure duration. With an extended exposure time, the porosity, cracking, and spalling of the rust layers increased, and the densification and thickness uniformity decreased. Electrochemical measurements displayed that the corrosion resistance of the rusted 700L steel gradually decreased with increasing exposure time. A good correlation was found between rust layer composition, microstructure, and corrosion resistance.

The role of low-quality calcined clay in enhancing the performance of cement mortar exposed to normal and aggressive media

This study focuses on the role of low-quality calcined Fanja (FNJ) clay in enhancing the behavior of cured cement mortar (CM) and its resistivity to chloride and sulfuric acid attack. Ordinary Portland cement was replaced with different quantities (10%, 25%, 35%, and 50% by weight) of FNJ, which was calcined at different temperatures (620 °C, 760 °C, and 900 °C). After 28 days of curing, all the hardened mortars were immersed in 5% sulfuric acid for up to 12 weeks. Additionally, a rapid chloride permeability test was conducted on the 91-day cured CM and CM-FNJ samples to evaluate the affinity of calcined FNJs to retard the chloride diffusion into CM. The results showed that all samples containing FNJ900 showed better physical and mechanical properties than the control sample, while CM with NFJ760 recorded nearly similar performance as CM-NFJ900. In contrast, the CM-FNJ620 mixtures showed lower properties than those of other mixtures. In addition to the pozzolanic reactivity of the calcined clay, the presence of hematite in the calcined clay strongly contributed to increasing the mechanical properties of the hardened mortar through forming calcium ferrosilicate hydrate binding phase, as confirmed by X-ray diffraction. Moreover, the existence of hematite increased the resistivity of CM against sulfuric acid attack as it acts as a buffer for an acidic medium. Compared with CM-FNJ900, the CM-FNJ760 is recommended for use as it exhibited a higher strength activity index and comparable resistance to accelerated chloride diffusion and sulfuric acid accompanied by lower energy demand and lower CO2 emission, achieving the concept of ‘sustainability’.

Potential protective efficacy of biogenic silver nanoparticles synthesised from earthworm extract in a septic mice model

Sepsis is an inevitable stage of bacterial invasion characterized by an uncontrolled inflammatory response resulting in a syndrome of multiorgan dysfunction. Most conventional antibiotics used to treat sepsis are efficacious, but they have undesirable side effects. The green synthesised Ag NPs were synthesized by 5 g of the earthworm extract dissolved in a volume of 500mL of distilled water and then added to 2,500 mL aqueous solution of 1mM silver nitrate at 40 °C. After 4 h, the mixture was then allowed to dry overnight at 60 °C. Later, Ag NPs were washed and collected. They were characterized by X-ray diffraction, ultraviolet-visible spectroscopy, and transmission electron microscopy. Sepsis model as induced by feces-intraperitoneal injection method. Eighteen male mice were assigned into three main groups: the control group, the sepsis-model group, and the Ag NPs-treated group. The control group received a single oral dose of distilled water and, after two days, intraperitoneally injected with 30% glycerol in phosphate buffer saline. The Sepsis-model group received a single oral dose of distilled water. Ag NPs - The treated group received a single oral dose of 5.5 mg/kg of Ag NPs. After two days, the sepsis-model group and Ag NPs-treated group were intraperitoneally injected with 200 µL of faecal slurry. Ag NPs treatment in septic mice significantly decreased liver enzyme activities, total protein, and serum albumin. Moreover, Ag NPs significantly enhanced kidney function, as indicated by a significant decrease in the levels of creatinine, urea, and uric acid. In addition, Ag NPs showed a powerful antioxidant effect via the considerable reduction of malondialdehyde and nitric oxide levels and the increase in antioxidant content. The histopathological investigation showed clear improvement in hepatic and kidney architecture. Our findings demonstrate the protective efficacy of biogenic Ag NPs against sepsis-induced liver and kidney damage.