Gravimetric Analysis Research Articles

Contribution of aeromagnetic and gravimetric data analysis to the study of geologic structures and deposits of the Rehamna massif (Western Meseta — Morocco)

Contribution of aeromagnetic and gravimetric data analysis to the study of geologic structures and deposits of the Rehamna massif (Western Meseta — Morocco)

Plasma‐Assisted Hydroxyapatite/Chitosan Bionanocomposite Films with Improved Thermal Stability, Biomineralization and Optical Absorption Properties

AbstractHydroxyapatite (HAp) is a well‐known precursor for synthesizing different bionanocomposite products for biomedical applications. For the first time, we aimed to evaluate the effects of plasma surface functionalization of HAp nanoparticles (NPs) on the chemical, physical, and bio‐functional properties of chitosan films using experimental and computational evaluations. Atmospheric air plasma process was conducted on HAp NPs at two different air pressures (650 and 1300 mTorr) and four different exposure times (1, 3, 6, and 9 min), followed by fabrication of HAp/chitosan bionanocomposites. Fourier transform infrared (FTIR) spectra proved that the position of bands at 1639 and 1037 cm−1 were shifted to 1635 and 1031 cm−1 due to the interaction between chitosan amine groups and HAp phosphate groups. Quantum mechanical and molecular dynamic (MD) simulations were used to understand the interactions between chitosan and HAp. Density functional theory (DFT) calculations were used to explore the electronic properties of untreated and plasma‐treated HAp (T‐HAp). MD simulations using the PCFF force field were used to investigate the interactions of HAp/chitosan and T‐HAp/chitosan bionanocomposites. According to the results from thermal gravimetric analysis (TGA), the duration of HAp NP plasma treatment is a significant factor in the weight loss properties for the resultant HAp/chitosan bionanocomposites. The overall reflectance % properties of films prepared with T‐HAp NP samples decreased, confirming the potential applications for skin tissue protection against solar UV radiation. The bioactivity of the bionanocomposite films was also studied by examining the HAp formation by incubating in simulated body fluid.

Optimized Production and Characterization of Auxin by Bacillus amyloliquefaciens (TSP11) for Plant Growth Promotion.

This study was aimed at isolating and recognizing the plant growth promoting rhizobacteria that secretes indole-3-acetic acid/auxin hormones. Among the 82 pure cultured bacterial morphotypes, the strain TSP11 showed high auxin production utilizing rice husk as a cheap substitute in the production medium. The minimal medium supplemented with 0.1 g/mL L-tryptophan and 1.29% rice husk produced the highest amount of auxin. Synthesized auxin was purified and quantified by chromatographic techniques. 120.08 µg/mL of synthetic medium and 135 µg/mL of agro-waste medium were the observed yields in HPLC quantification. Further GC-MS/MS and LC-MS/MS spectra exposed an existence of derived compounds such as 1H-indole, 7-methyl, indole, 3-methyl-, 1H-indole-3-carboxaldehyde (1H-indol-3-YL)-acetic acid. It was characterized by X-ray diffraction to reveal its crystallinity. Thermo gravimetric analysis showed the thermal stability of auxin over the range between 200°C and 300°C. Structural predictions of extracted auxin through HR-NMR revealed chemical shifts for Indole and acetate derivatives. The potent producer was identified as Bacillus amyloliquefaciens strain TSP11based on 16SrDNA gene sequencing. Increased seed germination percentage was observed when compared to untreated control. The research findings explore the possibility of exploiting B. amyloliquefaciens strain TSP11for bioformulations. This study represents an initial investigation into the plant growth-promoting potential of B. amyloliquefaciens strain TSP11, particularly regarding its auxin production using rice husk as a medium. We will explore the exact mechanism of auxin synthesis and its impact on various plant species in further studies.

Kevlar/Basalt and Kevlar/Glass Intra‐Ply Reinforced Hybrid Composites: Influence of Basket Weave Fabric Structure on Thermal Properties, Flammability, and Impact Performance

AbstractThis study investigates the influence of basket weave fabric structure and fibre combination on the thermal properties, flammability, and impact performance of intra‐ply reinforced hybrid composites. The objective is to evaluate the effect of varying the number of threads in the basket weave pattern (ten threads 5 × 5, six threads 3 × 3, and two threads 1 × 1) and different fibre combinations (Kevlar‐Glass (KG) and Kevlar‐Basalt (KB)) on composite performance. The composites were fabricated using a handloom weaving process followed by compression moulding. Thermal stability was assessed using Thermo Gravimetric Analysis (TGA), flammability was examined via the UL‐94 horizontal burn test, and impact performance was evaluated using the Charpy impact test. The results indicated that KG composites exhibited superior thermal stability, with higher final residue percentages and lower mass loss during degradation. The impact performance was significantly influenced by both fibre combination and weave structure, with KG5 × 5 and KB5 × 5 laminates achieving the highest impact strengths of 2160 kJ/m2 and 2040 kJ/m2, respectively. Flammability tests showed that all composites had a burn rate below 10 mm/min, meeting standard safety criteria. The findings highlight the potential of these hybrid composites for high‐performance applications requiring impact resistance and thermal stability, such as aerospace and protective equipment industries.

Synthesis and characterization of sustainable hybrid bio-nanocomposite of starch and polypropylene for electrical engineering applications

Abstract Plasticized potato starch being a sustainable, renewable, and cost-effective reinforcement has been melt mixed in this study with nano-TiO2 and polypropylene (PP) and compression molded into test specimens. Starch concentration was kept at 20%, whereas nano-TiO2 was varied as 1, 3, and 5% in the hybrid composites. Investigations were done for the dispersion of TiO2 and starch in the base polymer, and studies for the impact of nano-TiO2 on the mechanical, electrical, and thermal characteristics were also done. No adversative degradation in the dry arc resistance and dielectric property of the PP composites was found even at high starch loading of 20%, whereas mechanical characterization revealed a decline in percentage elongation and flexural strength but nearly similar tensile and impact strengths. Dynamic mechanical analysis studies showed a decrease in the mechanical strength of the bio-composite PPST-20, which improved upon the fusion of nano-TiO2. Uniform dispersion of nano-TiO2 in the morphological structure was examined using scanning electron microscopy, whereas intact melting behavior and increased crystallization temperature indicating the nucleating effect of nanofiller were verified using differential scanning calorimeter studies. Two-stage degradation patterns due to biomaterial and PP were also evident in the thermo gravimetric analysis studies.

Delineation of fault structure of offshore More Basin, Norway by integrating gravity, magnetic and seismic data

Abstract The Møre Basin (MB) is located in the mid-Norwegian margin, westward offshore of Norway. It is situated in the southern portion of this margin. The Ormen Lange gas field within the MB underscores the basin's potential for significant hydrocarbon resources. This study seeks to guide future resource exploration. Specifically, particulars regarding its form and size are currently unknown, while only a few studies have provided glimpses into its boundaries. We utilised satellite altimetry gravity and magnetic data in conjunction with analyses associated with these potential fields. Structural continuity was confirmed by conducting a thorough gravimetric and magnetic data analysis. Furthermore, we employed several filtering techniques, such as eliminating regional trends and applying a regional regularised correlation filter. Recurring anomalies were noticed across different processed maps to allow for a comprehensive geophysical interpretation of the area under examination, facilitating the proposal of the MB's boundaries. The results indicate four principal groups of faults, with numerous secondary faults existing at the boundaries. The gravity anomaly features are distributed in a NE-NEE-NW direction and can be divided into three sections from south to north. Several northwest-oriented cutting faults within the basin govern the secondary structures developed in this area. Additionally, in this region, the demarcation of prospective exploration zones identifies distinct attributes associated with each zone, which is mainly situated within areas presenting high local Bouguer gravity anomalies and steep gravity gradient transitions. Finally, the favourable areas for oil and gas have been delineated, categorising Norwegian oil and gas exploration zones into primary and secondary exploration zones.

Structural and Interfacial Characterization of a Photocatalytic Titanium MOF-Phosphate Glass Composite.

Metal-organic framework (MOF) composites are proposed as solutions to the mechanical instability of pure MOF materials. Here, we present a new compositional series of recently discovered MOF-crystalline inorganic glass composites. In this case, formed by the combination of a photocatalytic titanium MOF (MIL-125-NH2) and a phosphate-based glass (20%Na2O-10%Na2SO4-70%P2O5). This new family of composites has been synthesized and characterized using powder X-ray diffraction, thermal gravimetric analysis, differential scanning calorimetry, scanning electron microscopy, and X-ray total scattering. Through analysis of the pair distribution function extracted from X-ray total scattering data, the atom-atom interactions at the MOF-glass interface are described. Nitrogen and carbon dioxide isotherms demonstrate good surface area values despite the pelletization and mixing of the MOF with a dense inorganic glass. The catalytic activity of these materials was investigated in the photooxidation of amines to imines, showing the retention of the photocatalytic effectiveness of the parent pristine MOF.

Refractance window drying: A new approach for producing high-quality powdered dairy products.

Refractance window drying: A new approach for producing high-quality powdered dairy products.

Development of Chitosan/Carvacrol‐Based Hydrogels: Biocompatibility and Antimicrobial Activity Evaluation

AbstractChitosan hydrogels are gaining significant importance in the biomedical area field due to their application in wound dressings and drug delivery systems. In the present study, chitosan‐based hydrogels were developed and loaded with carvacrol at different concentrations. They were characterized by Fourier‐transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), and scanning electron microscopy (SEM). Their biocompatibility was assessed through direct hemolysis tests, yielding favorable results, as they were found to be safe for contact with blood. Another significant finding emerged from the antimicrobial tests, where the hydrogels achieved >95% inhibition against Staphylococcus aureus and >90% against Escherichia coli. Additionally, the hydrogels demonstrated a sustained release of carvacrol over at least 48 h. Those results suggest that chitosan/carvacrol‐based hydrogels are promising materials for medical applications, particularly as wound dressings, with biocompatible and antimicrobial properties, as well as for use in drug delivery systems.

Production and kinetic studies of composite sorbents based on methacrylic acid for the removal of aqueous uranyl ions

Uranyl ions (UO₂²⁺) are the form of uranium usually dissolved in water and are radioactive and can cause serious damage to the environment. Adsorption of uranyl ions is a critical method for removing and safely storing radioactive materials that harm the environment. It is also an important tool for combating water and soil contamination, managing nuclear waste and environmental sustainability. Polymer-based composites were developed for this purpose. Polymer-based composites enable the efficient removal of harmful and radioactive uranium compounds from water and soil. Through the incorporation of polymers and fillers (such as zeolite), materials with specific properties capable of adsorbing uranyl ions with high efficiency can be designed. The ratio of the components constituting the composites can be adjusted to optimize the adsorption capacity, as well as the chemical and thermal behaviors. Two composites were created: P(MA-Z50), consisting of ethylene glycol dimethacrylate (EGDM), methacrylic acid (MA), and zeolite, and P(MA-Z75), which contained a higher amount of zeolite. These composites were synthesized at room temperature and analyzed using various techniques such as Fourier transform infrared (FTIR), thermal gravimetric analysis (TGA), and scanning electron microscopy (SEM). The study investigated the effects of adsorbent quantity, adsorbate concentration, temperature, time, and pH on adsorption efficiency and capacity. The Langmuir adsorption isotherm provided the best fit for uranium (VI) adsorption. The results showed that rapid adsorption occurred within the first 100 min, with the rate slowing down until equilibrium was reached after 360 min. The pseudo-second-order kinetic model best described the adsorption process.

Preparation of nano(micro)particles from Cotinus coggygria Scop. extracts and investigation of their antimicrobial effects in vivo Caenorhabditis elegans model.

Preparation of nano(micro)particles from Cotinus coggygria Scop. extracts and investigation of their antimicrobial effects in vivo Caenorhabditis elegans model.

Enhanced biodegradation of high-density polyethylene microplastics: Study of bacterial efficiency and process parameters.

Enhanced biodegradation of high-density polyethylene microplastics: Study of bacterial efficiency and process parameters.

Effects of xanthan gum and hydroxypropyl methylcellulose on the structure and physicochemical properties of triticale gluten during fermentation.

Effects of xanthan gum and hydroxypropyl methylcellulose on the structure and physicochemical properties of triticale gluten during fermentation.

Preparation of graft copolymers from Vietnam deproteinized natural rubber with acrylonitrile using tetraethylenepentamine and tert-butyl hydroperoxide radical initiators

Natural rubber is an unsaturated natural elastomer with many superior properties such as high strength, outstanding resilience, and high elongation at break. However, it lacks in some properties due to the unsaturation of carbon-carbon double bonds in the natural rubber backbone causes easy degradation and poor thermal stability. Many techniques have been made use of improving its thermo-mechanical properties. In this study, the graft copolymerization of acrylonitrile onto deproteinization natural rubber was investigated to increase the thermal and mechanical properties of natural rubber. This process was performed successfully in latex using tetraethylenepentamine and tert-butyl hydroperoxide as radical initiators at 30 °C. The effects of acrylonitrile concentration on the conversion and grafting efficiency of the graft copolymerization were studied. The structural characterization of the obtain graft copolymer was carried out by Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy. The improvement in thermal properties of the obtained products was confirmed by Thermal Gravimetric Analysis/Differential Thermal Gravimetric Analysis, which showed that at the optimal condition for graft copolymerization was at acrylonitrile of 15 wt.% per kg of rubber, where the maximum degradation occurred at 377 °C. The mechanical properties of the products were also studied via tensile testing, where the tensile strength of the graft copolymerization using at AN of 15 wt.% per kg of rubber (1.5±0.5MPa), nearly tripled when compared to virgin deproteinized NR (3.8±0.9MPa).

Development of High-Performance Composite from Sugarcane Bagasse and Multi-Walled Carbon Nanotubes for Enhanced Adsorption Applications

A novel composite of sugarcane bagasse with multi-walled carbon nanotubes (MWCNTs) in the ratio of 3:1 (m/m), respectively, was prepared. The bagasse was initially combined with functionalized MWCNTs using an HNO3-H2SO4 mixture, after which it was crosslinked with glutaraldehyde. Several characterization techniques like SEM, TEM, FTIR, Raman spectroscopy and thermal gravimetric analysis, were used to demonstrate the successful functionalization of the MWCNTs and the covalent anchorage of the bagasse onto the functionalized MWCNTs. The composite was subsequently evaluated alongside bagasse for its effectiveness in removing heavy metal ions from a multi-component metal ion mixture through batch adsorption studies. The findings indicated the enhanced sorption properties for some heavy metals. This composite, therefore, shows good potential for applications that involve pre-concentration and removal of water pollutants.

Methods for Obtaining Humus Substances: Advantages and Disadvantages

The paper reviews the patent descriptions of methods for obtaining humic substances and the procedures used in their industrial production. Selected humus substances, obtained using three different methods, were also examined. In the first one, humic substances were obtained due to the hydrolytic-oxidative decomposition of lignosulfonate. The second one consists of alkaline extraction from brown coal. According to the third, humus substances were extracted from digested sewage sludge. In the obtained humus substances, molecular composition, inorganic impurities, IR spectrum, gravimetric analysis, and the % shares of fulvic and humic acids were determined. The physico-chemical properties of the tested substances were also assessed. Based on the study’s results, the advantages and disadvantages of the obtained humus substances were determined, and methods for their modification to improve utility values were provided. Research on humic substances is a very important issue, especially concerning improving soil management and developing sustainable agricultural practices. They are key in improving soil structure and increasing its capacity to retain water and essential nutrients such as N, P, K, S, Ca, and Mg. In addition, humic substances are an important store of carbon in soils, which is important in the context of climate change.

Effects on structural properties of doping zinc into Sn2Ba(Cu2−xZnx)2Oy ceramics

Abstract The study manifests the effects of different amounts of Zn doping on the structure of the nano ZnO-doped Sn2Ba(Cu2−xZnx)2Oy [x = 0.0,0.4,0.8,1.0] compounds synthesized by the solid state-reaction method. The structural changes in the produced materials have been characterized by differential thermal analysis (DTA), thermal gravimetric analysis (TGA), X-ray diffraction spectrometry (XRD), and scanning electron microscopy (SEM) methods. In the DTA analysis, while the endotherm was observed at 860 C in the pure material, the endotherms were at 810 and 880 C in the doped S10 material. The microstructure and surface morphology of pure and doped samples were analyzed using the SEM imaging method. SEM images show that the porous structure expected in Sn-based ceramics decreases and the grain size increases with the amount of Zn doping. XRD data were used to examine the crystal structures and determine the crystal phases. The effect of the ZnO dopant amount on phase transition was revealed. When the XRD peaks of the pure and doped samples are examined, it is seen that the lattice structures of both contain orthorhombic and tetragonal unit cells. It is determined Zn doping disrupts the structure of the orthorhombic 212 phase and has a positive effect on the development of the tetragonal 211 phase. It is determined that variation in the a, b, and c lattice parameters calculated using XRD data of Zn-doped materials is not monotonous. XRD analysis showed that the samples have Pmmm for the orthorhombic crystal structure and P4/mmm symmetry for the tetragonal crystal structure.

Characterization of NiCrAlY Layers Deposited on 310H Alloy Using the EB-PVD Method After Oxidation in Water at High Temperature and Pressure

In this paper, the oxidation behavior of the 310H alloy coated with NiCrAlY using the EB-PVD method is studied after exposure to water at a high temperature and pressure (550 °C and 25 MPa) for different periods (720 h, 1440 h, and 2160 h). The Electron Beam Physical Vapor Deposition (EB-PVD) method was used to obtain the NiCrAlY coating. After testing, the coating performance was carried out by gravimetric analysis, grazing incidence X-ray diffraction (GIXRD), scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), and the linear polarization method. GIXRD analysis highlighted the presence of chromium oxide (Cr2O3) and the Corundum phase (Al2O3) on the surface of the oxidized NiCrAlY-coated 310H samples. On the surface of the 310H alloy, the existence of the NiCrAlY coating and of the oxide film generated during oxidation are evident according to the EIS spectra, which show two capacitive semicircles in the Nyquist diagram. Furthermore, an increase in diameter semicircles with the oxidation time increasing was observed in the Nyquist diagram. Very low corrosion rates of 4.8 × 10−5 mm × year−1, which were observed for oxidization for 2160 h NiCrAlY-coated samples, indicated that the oxide films are more protective and provide better corrosion resistance, which is also evidenced by the EIS analysis. Considering the obtained results, a significant relationship between the electrochemical technique, scanning electron microscopy, and gravimetric analysis was established.

Effect of Degree of Ethoxylation on the Surface and Thermal Properties of Polymeric Ionic Liquids for Oilfield Applications.

Worldwide energy needs are growing, requiring new extraction techniques for crude oil from old reservoirs. However, conventional chemicals face difficulties when exposed to harsh reservoir environments such as solubility in high saline water and heat stability under harsh reservoir environments. This study investigates the potential of newly synthesized polymeric ionic liquids (PILs) as alternative options. A series of PILs was synthesized and characterized by using NMR and FTIR techniques. It was noticed that a PIL without ethoxy groups exhibits precipitation and therefore is not suitable for oilfield applications. However, the incorporation of ethoxy groups in the chemical structure of PILs leads to excellent solubility in low to high salinity brine. The solubility of the synthesized PILs in formation water, seawater, and deionized water, as well as their thermal stability using thermal gravimetric analysis (TGA), was assessed. In addition, the surface properties, including critical micelle concentration (cmc), surface tension (γcmc), surface excess concentration (Γmax), minimal surface area per molecule (Amin), free adsorption energy (ΔG°ads), and free micellization energy (ΔG°mic), were also evaluated. The findings revealed that adding ethoxy groups in PILs led to a drop in Γmax and an increase in Amin, suggesting reduced monolayer compactness at the air/water interface. The synthesized PILs demonstrated remarkable solubility, heat stability, and resistance to salt, rendering them well-suited for oilfield applications under challenging reservoir environments.

Enhanced stability of curcumin and polyethylene glycol composites in the presence of flavonoids and whey protein concentrate: synthesis, structural evaluation and thermal analysis

Abstract Curcumin (CCM) is a natural polyphenol with promising pharmacological potential. This potential is severely restricted, however, due to its limited bioavailability, poor solubility and stability. To address this, several systems of curcumin and polyethylene glycol, PEG (PEG4000 or PEG6000), were synthetized, with or without whey protein concentrate (WPC), trans-resveratrol (RES) or silymarin (SIL) using solid dispersion technique. Firstly, CCM-PEG composites were synthesized using PEG4000 or PEG6000 for 1:8 mol ratio by polymer melting method. Further, the CCM-WPC-PEG4000 composite for 1:0.4:8 mol ratio and CCM-WPC-PEG6000 composite for 1:0.5:10 mol ratio were synthesized. Furthermore, CCM-RES-WPC-PEG and CCM-SIL-WPC-PEG composites were prepared for 1:2.5:0.4:10 mol ratio for PEG4000 or PEG6000. The composite formation was investigated by Fourier transform infrared spectroscopy (FTIR). The thermal stability of synthesized composites was analyzed through thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) revealing a high stability up to 200 °C. Thus, each composite formulation was optimized to carry CCM, RES and WPC or CCM, SIL and WPC within PEG matrix primarily by hydrogen bonds and van der Waals interactions. This study demonstrated that all synthesized composites may have potential advantages for applications such as nutraceuticals, functional foods, supplements and pharmaceuticals.