Lower Energy Values Research Articles

Green-engineered clay- and carbon-based composite materials for the adsorption of benzene from air

Benzene is a carcinogenic volatile organic compound (VOC) that is ubiquitously detected in enclosed spaces due to emissions from cooking activities, building materials, and cleaning products. To remove benzene and other VOCs from indoor air and protect public health, traditional fabric filters have been modified to contain activated carbons to enhance the filtration efficacy. In this study, composites derived from natural clay minerals and activated carbon were individually green-engineered with chlorophylls and were attached to the surface of filter materials. These systems were assessed for their adsorption of benzene from air using in vitro and in silico methods. Isothermal, thermodynamic, and kinetic experiments indicated that all green-engineered composites had improved binding profiles for benzene, as demonstrated by increased binding affinities (Kf ≥ 900 vs 472) and lower values of Gibbs free energy (ΔG = −16.8 vs −15.2) compared to activated carbon. Adsorption of benzene to all composites was achieved quickly (< 30 min), and the green-engineered composites also showed low levels of desorption (≤ 25%). While free chlorophyll is known to be photosensitive, chlorophylls in the green-engineered composites showed photostability and maintained high binding rates (≥ 70%). Additionally, the in silico simulations demonstrated the significant contribution of chlorophyll for the overall binding of benzene in clay systems and that chlorophyll could contribute to benzene binding in the carbon-based systems. Together, these studies indicated that novel, green-engineered composite materials can be effective filter sorbents to enhance the removal of benzene from air.

Molecular Docking and Molecular Dynamic Simulation on the Interaction of Saffron’s Active Compunds with HER-2 Protein

Human epidermal growth factor receptor-2 (HER-2) is an essential oncogene in breast cancer. HER-2 causes 25% of breast cancer, and this type of cancer tends to grow and spread faster than others but had a good response to HER-2 targeted therapy. This study aims to analyze chemical compounds in saffron plants (Crocus sativus) that potential to breast anticancer activity by inhibiting HER-2 receptor (PDB ID: 3RCD). The study employed in silico research such as molecular docking using AutoDock Tools software, and visualization with Biovia Discovery Studio. In addition, molecular dynamic simulation was conducted using GROMACS software, with visualization performed using Grace. The molecular docking results showed that Crocetin has a lower binding energy value of -8.37 kcal/mol compared to Herceptin, which is -7.11 kcal/mol and the lowest energy among Saffron bioactive compounds. These results indicated that the affinity of Crocetin in binding to HER-2 receptor is better than Herceptin. The molecular interactions were hydrogen, hydrophobic, electrostatic, and unfavorable bonds. The MD results showed that the RMSD value meets the 0.2-0.5 nm stability requirements. According to the data analysis, Herceptin appears to have a more stable RMSF value when compares to Crocetin. The Rg graph of both complexes showed stability until the end of the simulation. The H-bond results show that the Herceptin complex has more hydrogen bonds than the Crocetin complex. These results showed that the chemical components of saffron plants have the potential as breast anticancers by inhibiting the HER-2 receptor.Keywords: anticancer, Crocus sativus, HER-2 receptor, molecular docking, molecular dynamic.

Design of new dipeptide inhibitors against SARS-CoV 3CLpro: 3D-QSAR, molecular docking, MD simulation, ADMET studies and retrosynthesis strategy

The 3CL protease plays a crucial role in the life cycle of SARS-CoV. This protease is considered an important antiviral target. In the present work, the 3D-QSAR study was performed on a set composed of twenty-six dipeptide SARS-CoV 3CLpro inhibitors in order to propose the new potent anti-SARS agents with a high predicted activity value. The model of CoMSIA/SH is the optimal, with good statistical results presenting a high value of the cross-validation coefficient Q2 = 0.796 and a good value of the determination coefficient R2 = 0.887, the external validation of this model is justified by the high value of the prediction coefficient R2pred = 0.884 and the validation of Globraikh, Roy and Tropsha criteria. The exploitation of the different results provided key information about the structures favored to improve the inhibitory activity against 3CLpro, and has enabled us to propose seven new potent inhibitors with significant predictive activity values, notably compound M−1 with pKipred = 7.080. Then, a molecular docking study was performed to determine the binding energy and to identify the key interactions between the receptor (PDB ID: 1WOF) and the ligands. All the newly designed compounds showed low binding energy values as compared to the Remdesivir −8.144 kcal. mol−1 especially for compounds M−5 and M−4 with the binding affinity values −10.022 kcal. mol−1 and −9.727 kcal.mol−1 respectively. In addition, these inhibitors were verified for in silico pharmacokinetic proprieties and toxicity profile using ADMET. Two compounds M−4 and M−5 with potential results in the molecular docking were selected for the molecular dynamic simulation of 100 ns. The MM-GBSA results show that the predicted compound M−5 has the lowest free energy with −38.200 KJ/mol. We exploited the computer-aided synthesis technology using the ASKCOS website to perform a retrosynthetic analysis of compound M−5.

A DFT study the role of pristine and metal doped of g-CN nanosheet for drug delivery system

This research focuses on investigating how a targeted drug delivery system (DDS) can improve distribution and bioavailability of a drug on tumor cells. Specifically, study examines the use of pristine and Al-doped graphitic carbon nitride (C3N) sheets as the delivery system. By employing density functional theory (DFT), researchers analyze interaction between anticancer drug cisplatin (Cis) and sheets. Results demonstrate that doping process modifies characteristics of pristine sheets, leading to improved adsorption of anticancer drugs. Al-doped sheet exhibits a cohesive energy within range of 4.96 eV, indicating its high stability. Present work has uncovered that adsorption of Cis drug over pristine C3N sheet is weak, with low adsorption energy (Eads) values of approximately −3.26 eV and −2.19 eV in a gaseous (aqueous) phase, respectively. However, Eads is significantly enhanced by approximately 85.92 % through introduction of Al doping in pristine C3N sheet. Primary interactions within the complexes are examined employing non-covalent interaction (NCI) analysis, utilizing a reduced density gradient (RDG) map. Cis@Al-C3N complex reveals that non-covalent interactions have a significant role in drug adsorption. Moreover, NCI indicates van der Waals interactions exert a substantial impact on interaction between carrier sheets and anticancer drug. Present investigation sets foundation for future research focusing on utilization of doped C3N sheets as effective drug carriers in targeted DDSs, potentially benefiting a wide range of drugs.

Comprehensive Characterization of Micronized Wholemeal Flours: Investigating Technological Properties across Various Grains.

With a suitable milling system, it is achievable to produce wholegrain flours that match the granulation and technological properties of refined flours while maintaining a complete nutritional profile. This process also minimizes the generation of additional industrial waste. This study aimed to characterize wholemeal flours with a fine granulation size of less than 160 µm: wheat (MWF), rye (MRF), spelt (MSF), barley (MBF), buckwheat (MBWF), and sorghum (MSGF). For comparison, the plain wheat flour type 530 (T530) was analyzed. The flours were assessed in terms of their chemical compositions and alpha amylase activities (the Falling Number assay), pasting properties (amylograph and a Rapid Visco Analyser (RVA)), water absorption using a farinograph, and technological quality based on their water (WRC) and sodium carbonate solvent retention capacity (SRC) profiles. Among the micronized wholemeal flours, wheat flour (MWF) exhibited the highest nutritional value, greatest water absorption, and highest final gelatinization temperature, but had the lowest energy value, carbohydrate content, water SRC, and sodium carbonate SRC. Wholemeal rye flour (MRF) displayed the lowest nutrient content and the highest amylolytic activity, water absorption, and sodium carbonate SRC. The plain wheat flour type 530 (T530) had the lowest water absorption. Special buckwheat flour (MBWF) showed the highest energy value due to its elevated carbohydrate content, along with the lowest sugar and TDF contents, amylolytic activity, and pasting temperature.

Superhydrophobic Coatings for Corrosion Protection of Stainless Steel

Corrosion is a persistent challenge in the aviation industry, affecting the safety, performance, and maintenance costs of aircraft. While composite materials have gained widespread use due to their lightweight properties and corrosion resistance, certain critical parts, such as the wing and empennage leading edges and the engine inlet, demand alternative solutions. Aluminum, titanium, and stainless steel emerge as mandatory materials for such components, given their exceptional strength and durability. However, protecting these metallic components from corrosion remains crucial. In this paper, we present a study aimed at evaluating the corrosion resistance of stainless steel, employed as an erosion shielding panel for a composite vehicle’s wing, layered with a superhydrophobic coating. The samples with and without coating have been characterized by contact angle measurements, microscopy (optical and electronic), and visual inspection after immersion in two solutions, NaCl and NaOH, respectively. The application of the superhydrophobic coating demonstrated a significant reduction in corrosion extent, especially in the demanding NaCl environment. This was evidenced by diminished formation of ripples and surface roughness, decreased iron oxide formation from oxidative processes, and a lower Surface Free Energy value in both liquid environments. Notably, the surface maintained its superhydrophobic properties even following an 8-day immersion in NaCl and NaOH solutions, demonstrating the reliability of the superhydrophobic coating offering as a potential solution to enhance the longevity and reliability of aircraft structures.

Impact of the As2O3/B2O3 ratio on the structure and optical features of As2O3–NiO–Na2O–B2O3 glass

The impact of the As2O3/B2O3 ratio on the microstructure, linear and nonlinear optical parameters of nickel borate glass was carefully investigated for the As2O3–NiO–Na2O–B2O3 system. The As2O3 content of the present glass were varied from 0 to 16 mol%, while the glass modifiers of Na2O and glass intermediate of NiO were fixed at 18 and 1 mol%, respectively. Based on the structural investigations, the density increased from 2.52 gcm−3 to 2.95 gcm−3 and the molar volume increased from 27.11 cm3.mol−1 to 30.07 cm3.mol−1 with increasing As2O3/B2O3 ratios. Additionally, the presence of Ni2+ ions as NiO6 units was confirmed by the brown color originating from the absorption band observed at 421–428 nm in the optical absorbance of the studied glass. Furthermore, the Ni3+ ions do not participate in the coloring of the glass. Moreover, the fundamental absorption edges of the glass shift towards lower energy values with increasing As2O3/B2O3 concentrations, confirming the decreased behavior of the band gaps. Furthermore, the nonlinear refractive index increases with the increased As2O3/B2O3 concentrations. Additionally, the ligand field parameters of Ni cations, such as the ligand field splitting parameter and Racah parameter, exhibit opposite behaviors upon introducing additional As2O3/B2O3 ratio. A decrease in values of the ligand field splitting, while the Racah parameter exhibits increased values. The observed outcomes demonstrate a tendency of the bonds connecting the Ni ions and their ligands to possess higher degrees of ionic nature. Besides, the ionizing radiation properties for the prepared glasses were studied using online “Phy-X″ software in the energy range of 0.248–1.33 MeV. The ionizing radiation shielding invistigations showed enhanced parameters with further As2O3 additives. Where, with increasing the amount of As2O3 from 0 mol% to 16 mol%, there are increases in the mass attenuation coefficient values. Additionally, the half value layer values of the studied glass samples are lower than the values of most standard ionizing radiation shielding materials. The effective As2O3/ B2O3 ratio enhanced structure, optical and radiation shielding parameters of the present glass system, making these glasses suitable for ionizing radiation shielding applications.

Advancing sustainability with inverse vulcanization of waste sulfur catalyzed with TiO2

There is a need for sustainable valorization solutions for the problem of excess sulfur arising from abundant natural sources of sulfur and the production of millions of tons of sulfur annually as a byproduct of refineries. Developing sulfur-based polymers with enhanced mechanical properties using the process of inverse vulcanization could be a valuable endeavor, since the poor mechanical properties of current sulfur polymers limit their scale-up and widespread application. Herein, we studied the performance of titanium oxide (TiO2) in improving the mechanical properties of the sulfur polymer through copolymerization with oleic acid. To study the efficacy of TiO2 and oleic acid in copolymerization with sulfur. we used laboratory experiments and a computational approach geared toward the use of the density functional theory (DFT). Based on the DFT results, the coordination of the third and fourth ligands (oleic acid chains) to the Ti4+ ion are not as strong as the coordination of the first two ligands mainly because of the high steric hindrance around the metal ion. The low values of binding energy for Ti2+–di oleate and Ti+–tri oleate make them more accessible to sulfur chains. This in turn, promotes the cross-linking reactions in a process of inverse vulcanization. This was further reflected in an increase of up to 637.3% in sulfur–oleic acid blends in presence of TiO2. This study contributes to the sustainable use of abundant sulfur and the sustainable development of the polymer industry.

Effect of log Kow on the degradation of pharmaceutically active compounds in a heterogeneous catalytic persulfate activation system

In heterogeneous catalytic advanced oxidation processes (HC-AOP), enhancing the reaction rate is the biggest challenge. To enhance the reaction rate, it is necessary to increase the mass transfer rate of reactants toward the catalyst surface and the number of active sites that will provide better contact with the reactants and higher mass transfer. The hydrophobicity of the reactant is an important parameter that affects the transport of molecules toward solid surfaces. In this study, the effect of log Kow, an indicator of hydrophobicity, on enhancing the catalytic activity in persulfate (PS) activation for pharmaceutic compounds (PCs) degradation was investigated. For this purpose, some PCs with different log Kow were selected and their adsorption and degradation behaviors were investigated depending on the PS concentration, catalyst dosage, contact time, pH, and temperature in HC-AOP. Adsorption percentages increased significantly with increasing log Kow value. PCs with higher log Kow were completely degraded at the end of the shorter contact times in the presence of lower catalyst and PS. PCs were significantly degraded by the triple catalytic effect of AC, Fe, and temperature. The pseudo-first-order kinetic model was the best fit for the degradation reaction for all PCs. The higher apparent rate constants and lower activation energy values of the PCs belonging to high log Kow confirmed that log Kow is an effective parameter in enhancing the catalytic activity.

Impact of Anisotropy and Electromagnetic Modified Effect on Fluid Mobility in Reservoir Sandstone

The oil and gas sector faces challenges in optimizing oil recovery from reservoirs due to trapped oil due to interfacial tension and surface forces. Characterizing anisotropic dielectric properties is crucial. The petroleum business is quickly changing, and a massive advancement in the application of nanotechnology in this field is envisaged. Because magnetic nanoparticles (MNP) are solid, tiny, and adsorb at the oil-water interface, they might be helpful. The interaction of MNP with electromagnetic waves appears to be capable of altering interfacial tension, which will boost oil recovery. The interaction of an oscillating B-field of electromagnetic waves with magnetic domains causes energy dissipation due to a shift in magnetic anisotropy from the easy axis of magnetization. The use of anisotropy energy in mobilizing oil in a porous media has recently been investigated. BaTiO3 nanoparticles (NPs) were synthesized for this purpose, and their influence on oil mobility under electromagnetic waves (EM) was studied. The anisotropy energy was computed and determined to be 7.34kJ/mol. Under EM, the easy axis magnetization of BaTiO3 nanoparticles oscillates and changes direction continually, facilitating oil mobilization in the porous media. The EM findings for reducing interfacial tension (IFT) between oil and water ranged from 4.5mN/m to 0.89mN/m. Under EM, it was discovered that BaTiO3 nanoparticles might lower IFT by roughly 60%. The IFT must be small enough to allow oil flow during mobilization. The simulation findings demonstrate that the adsorption energy of n-hexane on the surface of hematite has a 47.9% lower energy value than water. With a 115.4% percentage difference, the stress autocorrelation function of n-hexane with hematite is greater than that of water.

Treatment methodology for sludge and scale TENORM waste from petroleum industry in Egypt

In this present laboratory work, experiments have been steered to decrease the activity concentration of 226Ra in sludge and scale (TENORM) which Technically Enhanced Naturally Occurring Radioactive Materials waste samples deposited in oilfield tubes and tools, sludge and scale, Egypt, respectively. The influence of the leaching parameters on the radium dissolution mechanism using nonionic surfactant tween 20 as a leaching agent has been determined. The greatest leaching percent of radium isotopes approximated 58.31 % of the total radium percentage in bulk sludge TENORM waste sample (size < 2.5 mm) using tween 20 as surfactant solutions through three successive cycles at the optimum conditions. The greatest leaching percent of radium isotopes was 77.98 and 86.12 % of the total radium percentage in scale TENORM waste samples from two different places, the first place is the western desert area and the second place is Ras Shukeir area, respectively, (size < 1 mm) using tween 20 solutions through four successive cycles at the optimum conditions. The kinetic calculations indicated that the leaching procedure can be explained by the Shrinking Core Model with activation energy equivalent to 18.18 kJ/mol. The low value of activation energy illustrated that the diffusion process controls the sludge TENORM waste sample leaching rate. The estimated values of thermodynamics parameters (ΔG°, ΔH°, ΔS°) were appointed in this study and showed the dissolution of radium is a non-spontaneous response and temperature dependent.

Theoretical Analysis of Composite RC Beams with Pultruded GFRP Beams subjected to Impact Loading

Glass Fiber Reinforced Polymer (GFRP) beams have gained attention due to their promising mechanical properties and potential for structural applications. Combining GFRP core and encasing materials creates a composite beam with superior mechanical properties. This paper describes the testing encased GFRP beams as composite Reinforced Concrete (RC) beams under low-velocity impact load. Theoretical analysis was used with practical results to simulate the tested beams' behavior and predict the generated energies during the impact loading. The impact response was investigated using repeated drops of 42.5 kg falling mass from various heights. An analysis was performed using accelerometer readings to calculate the generalized inertial load. The integrated acceleration record and the measured hammer load vs. time data were utilized to determine the generalized bending load and fracture energy. Four forms of energy were calculated at the maximum load. The total energy was calculated and divided into two parts: The first part was gained by the beam's rotational kinetic energy, the bending energy in the specimen, and the elastic strain energy. The second part was the hammer's kinetic energy before striking the beam. The analytical results showed that the bending energy was less than its rotational kinetic energy for the encased GFRP beams and the reference specimens. In contrast, the encased steel beams had high bending energy due to the higher impact load and deflection. Strain energy recorded lower energy values for all specimens with higher bending energy. There is a good agreement between the tested and the calculated inertial and bending force for all beams. The ratio of inertia force to the total impact load for the encased GFRP and encased steel beams to the reference beam is about 9% and 5%, respectively.

Influence of the La2O3 addition on the structure and optical features of La2O3–NiO–BaO–B2O3 glass

The influence of the La2O3 addition on the microstructure, linear and nonlinear optical parameters of nickel borate glass was carefully investigated for the La2O3–NiO–BaO–B2O3 system. The La2O3 content of the present glass was varied from 0.0 to 10.0 mol%, while the glass modifiers of BaO and glass intermediate of NiO were fixed at 19 and 1.5 mol%, respectively. Based on the structural investigations, the bond density remarkably increased from 7.37 × 1019m−3 to 8.66 × 1019m−3 by a ratio of 18 % with increasing La2O3/B2O3 ratios. Additionally, the presence of Ni2+ ions as NiO6 units was confirmed by the brown shade originating from the absorption band observed at 427 nm in the optical absorbance of the studied glass. Furthermore, the Ni3+ ions do not play a role in the coloring of the glass. Moreover, the fundamental absorption edges of the glass shift towards lower energy values with increasing La2O3 concentrations, confirming the decreased behavior of the band gaps. Moreover, the linear and nonlinear refractive indices increase with increasing of La2O3 concentrations. Additionally, the ligand field characteristics of Ni cations, such as the ligand field splitting parameter and Racah parameter, exhibit opposite behaviors upon introducing additional La2O3 content. A decrease in values of the ligand field splitting, while the Racah parameters exhibit increased values. The observed outcomes demonstrate a tendency of the bonds connecting the Ni ions and their ligands to possess higher degrees of ionic nature. Based on the results, the present glass samples can function as solar thermal collectors by collecting sunlight and utilizing it for direct heating and indirect electrical power generation.

Metal-adorned borophene for efficient glucose adsorption

In view of the urgent need for developing new materials for biomedical applications, we report on multi-facet study of functionalized borophene as a possible sensor or transporter of glucose. The adsorption of a glucose molecule on [MB36]+(M = Li, Na, K), [MB36]2+ (M = Be, Mg, Ca), and [MB36]3+ (M = B, Al, Ga) complexes were studied both in gas and in water phase, conforming that [MB36]+, [MB36]2+, [MB36]3+ are highly efficient as glucose adsorbers with the binding energies of −34 to −135 kcal/mol in the gas phase, and −12 to −111 kcal/mol in water as calculated with the PBE0-D3/def2-TZVP. Borophene adorned with beryllium have the highest adsorption energies, while the complexes with Li, Na and K are characterized with lower binding energy values. Thus, the systems with 1+ oxidation state are more promising for intelligent drug delivery, while [MB36]+, [MB36]2+, [MB36]3+ are more suitable for designing biosensors of glucose.

In silico analysis of identified molecules using LC–HR/MS of Cupressus sempervirens L. ethyl acetate fraction against three monkeypox virus targets

Monkeypox virus is a viral disease transmitted to humans through contact with infected animals, such as monkeys and rodents, or through direct contact with the bodily fluids or lesions of infected humans. The aim of this study is to evaluate in silico the inhibition effect of eight Cupressus sempervirens L. ethyl acetate fraction identified molecules using LC-MS on three monkeypox targets such as the vaccinia virus thymidylate kinase (VTK), the viral profilin-like protein (VPP), and the viral RNA polymerase (VRP). The study consist of using molecular docking with AutoDock vina based on the lowest energy value in kcal/mol, pharmacokinetics prediction with pre-ADMET v2.0 server, and prediction of biological activity with the PASS server tool. The best complexes were subjected to molecular dynamics simulation (MD) study to confirm their stability using Desmond software. The used molecules were vitamin C, vanillic acid (Pol), Flav1 (Catechin), Flav2 (Epicatechin), Flav3 (Hyperoside), Flav4 (Luteolin), Flav5 (Taxifolin), and Flav6 (Quercetin). The results show that flavonoids are potent to VTK, VPP and effectively block the VRP channel with energy values ranging from −7.0 to −9.3 kcal/mol. Further, MD simulation supports Flav1 and, Flav2 for notable stability in the VTK binding pocket through hydrogen and hydrophobic interactions. PASS results predicted various biological activities with promising VTK and VRP inhibition activities. The studied molecules could constitute a safer alternative to current drugs, which often cause adverse side effects. Communicated by Ramaswamy H. Sarma

Zero-carbon-driven multi-energy coordinated sharing model for building cluster

The energy sharing among different intelligent buildings can improve renewable energy consumption and reduce carbon emission. However, the evaluation of the low carbon value of energy sharing is insufficient. Considering the different percentage of generated power of energy production units on the energy supply side during different periods, this study is the first to use time-of-use carbon emission evaluation factor to calculate the carbon emissions generated by buildings purchasing energy from upper-level networks. Then, an incentive-based carbon reward and punishment model is proposed based on the evaluation model. Meanwhile, operation decision models for different types of intelligent buildings are proposed. The optimal strategies for peer-to-peer energy sharing for intelligent buildings are obtained by the distributed algorithm. Results show that (1) The time-of-use carbon emission evaluation factor can facilitate the change of equipment output and energy consumption plans in buildings, and further improve the benefits of multi-energy sharing. (2) The proposed incentive-based carbon reward and punishment method shows greater advantages in reducing carbon emissions of high carbon emission buildings compared to the traditional carbon reward and punishment method. Although the benefits of some low carbon emission buildings with the proposed method may be sacrificed, CO2 emissions reduce by 7% for the entire building cluster.

Improvement of corrosion resistance for brass in 3.5% NaCl media by using 4- fluorophenyl-2, 5-dithiohydrazodicarbonamide

Corrosion poses a significant challenge for numerous industries. The use of corrosion inhibitors is essential within these industries. The efficacy of environmentally friendly corrosion inhibitors should remain high even when used at low concentrations. In the present study, the compound 4- fluorophenyl-2,5- dithiohydrazodicarbonamide (FTSC) was used as a corrosion inhibitor for brass in 3.5% NaCl solution. The inhibitor efficiency was determined by using a series of electrochemical techniques such as open circuit potential (OCP), potential dynamic polarisation (PDP), linear polarisation resistance (LPR), and electrochemical impedance spectroscopy (EIS). All experimental tests have been done in stagnant conditions. The findings of the experiments revealed that the compound FTSC looked to be of the cathodic type. Furthermore, the maximum inhibitor efficiency was reached at 98.28% at 1 × 10-3 and at an immersion time of 1 h. The current density was reduced from 16.5 to 0.284 A.cm-2. The adsorption of compound on the brass surface in 3.5% NaCl solution obeyed the Langmuir isotherm with a low negative value of the standard Gibbs free energy of adsorption (-33.8 kJ/mol ΔGads (chemisorption and physisorption). The results confirmed that the compound FTSC can be used as a corrosion inhibitor for brass in 3.5% NaCl.

Unveiling the role of transition metal catalysts in low-temperature, liquid-phase isopropanol oxidation

Driven by the increasing need to optimize industrial chemical reactions through effective catalysts, this study reports the comprehensive oxidation process of isopropanol under liquid phase conditions at subambient temperatures, investigating the catalytic potential of transition metal oxides. The complete oxidation of isopropanol within the liquid phase at reduced temperatures was investigated, employing transition metal oxides as catalysts (Cr2O3, Fe2O3, NiO, and ZnO). These solids were prepared using the sol–gel method and the precipitation method. The results from structural (FTIR, XRD) and textural (BET) analyses were consistent with those reported in the literature. The employed solid substances exhibited favorable catalytic activity for the full oxidation of isopropanol, maintaining a consistent selectivity of 100 %, regardless of the temperature conditions under examination (40, 60, and 80 °C). These catalytic tests reveal that chromium oxide is a typical catalyst for this type of reaction. Furthermore, a kinetic analysis of the reaction was conducted, revealing that the reaction proceeds according to a sequential A-B-C mechanistic pathway. The low values of apparent activation energy for all the solids align with the high initial reaction rates in the studied temperature range. This study revealed the effective role of transition metal oxides, particularly chromium oxide, as catalysts for the total oxidation of isopropanol under liquid phase conditions at subambient temperatures, offering vital insights to enhance efficiency in chemical industrial processes.

On the importance of nano-oxide control in laser powder bed fusion manufactured Ni-based alloys to enhance fracture properties

In this study, a series of Ni-Cr-Mo based alloys (IN625, C22 and NA282), sourced from various powder suppliers and having varying oxygen concentrations (200 ppm to 800 ppm), were printed under similar conditions using laser powder bed fusion (LPBF). Nano-oxides in the range of 20–50 nm were observed in each alloy in the as-printed state, albeit with different number densities. Room temperature tensile tests and liquid nitrogen (LN2, -196 °C) Charpy impact tests were performed to assess the mechanical response of each alloy. The IN625 and C22 samples showed considerably lower impact energy values than the NA282, as well as lower room temperature post-necking tensile elongations, despite showing similar yield strengths and strain hardening behaviours. Fracture surface dimple sizes were shown to correlate with nano-oxide particle spacings. Nano-oxides were found in the middle of most dimples on fracture surfaces suggesting that the nano-oxides are the sites of void nucleation during fracture, despite being only 20–50 nm in size. The precursor metal powders were identified as the primary origin of the nano-oxide particles. This study highlights the critical, detrimental role that nano-oxides, typically present in LPBF metals, have on the fracture properties of these materials. In the case of the Ni-Cr-Mo alloys examined here, limiting oxide formation is critical to achieving optimal fracture properties.

Investigation of low bandgap Rb2InAsCl6 and Rb2InAsBr6 compounds for energy harvesting applications

Herein, halide double perovskites (HDPs) Rb2InAsCl6 and Rb2InAsBr6 are reported for their physical characteristics by employing DFT. The analysis of tolerance factor (τG) and enthalpy of formation (ΔH) revealed the geometrical and thermodynamical stability. Both HDPs show direct bandgap with bandgap of 0.76 eV for Rb2InAsCl6 and 0.19 eV for Rb2InAsBr6. This low bandgap behavior is mainly originated from a collective effect of In-4p, As-5p and Cl/Br-3p/4p states. Further, low optical threshold absorption energy values indicate the optimal amount of optical conductivity in infrared and visible region of light indicating the suitability of considered HDPs for low bandgap optoelectronics. In addition, figure of merit (ZT) for both HDPs is reported greater than 0.8 at room temperature. Presented study exemplifies the importance of exploring various cationic combinations in HDPs in an effort to obtain suitable contenders for advanced technological applications including IR sensors, TEGs, and optical filters.