Effects of Short-Term Annealing on the Thermal Stability and Microstructural Evolution of Oxygen-Free Copper Processed by High-Pressure Torsion.

This study explores the impact of short-term annealing on the thermal stability and mechanical properties of oxygen-free copper subjected to high-pressure torsion (HPT). Copper samples were deformed through HPT with varying numbers of turns at room temperature and subsequently subjected to short-term annealing at temperatures of 398 K and 423 K. Microstructural analysis revealed that annealing led to grain growth and a reduction in dislocation density, with samples processed with fewer HPT turns exhibiting more significant grain coarsening.

Improved hydrogen production performance of an S-scheme NbO/LaO photocatalyst.

Addressing the intricate challenge of simultaneously improving the separation of photoinduced electron-hole pairs and enhancing redox potentials to produce hydrogen fuel demands the rational design of S-scheme heterojunction photocatalysts. Herein, we used a hydrothermal process to integrate NbO nanorods and LaO nanosheets to design an NbO/LaO S-scheme system for photocatalytic hydrogen production under simulated sunlight illumination. Notably, the optimal hydrogen production performance of NbO/LaO (the molar ratio of NbO to LaO is 0.

Microstructure and Microhardness Evolution of Mg-8Al-1Zn Magnesium Alloy Processed by Differential Speed Rolling at Elevated Temperatures.

Mg-8Al-1Zn magnesium alloy was successfully processed using deferential speed rolling (DSR) at temperatures of 400 and 450 °C for thickness reduction of 30, 50, and 70% with no significant grain growth and dynamic recrystallization. Using optical microscopy (OM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), the rolled microstructures were examined. Although the results indicate a slight reduction in grain size from the initial condition, the DSR processing of alloy at an elevated temperature was associated with a significant number of twins and a distribution of the fine particles of the second phase.

An Explicit Data-Driven Model for Estimation of Free and Absorbed Gas Volumes in Shale Gas Reservoirs.

Shale gas reservoir fluid flow is characterized by complex interactions between a number of variables, including stress sensitivity, matrix shrinkage, and critical desorption pressure. The behavior and productivity of shale gas reservoirs are significantly influenced by these variables. Therefore, in this study, an in-house finite element poro-elastic simulator was integrated with an in-house Fortran-coded artificial neural network model for accurate estimation of free and absorbed gas volumes in shale gas reservoirs, taking into account the combined effects of stress sensitivity, matrix shrinkage, and critical desorption pressure.

Explicit Data-Based Model for Predicting Oil-Based Mud Viscosity at Downhole Conditions.

One of the functions of drilling mud is to transport cuttings out of a drilled well. To fulfill this purpose, the mud must possess optimal viscous characteristics. The main goal of this study is to develop a model for estimating the plastic viscosity (PV) of oil-based muds (OBMs) at downhole conditions, especially when high-temperature, high-pressure wells are drilled.

Solid-State Synthesis of Liquorice-Stabilized Copper-Based Nanoparticles: Structural and Catalytic Studies.

A large-scale quantity of copper oxalate nanoparticles were successfully obtained via a facile and green solid-state chemical reaction. Copper oxalate nanoparticles were obtained by ball-milling between copper chloride, Liquorice (Glycyrrhiza glabra), and ascorbic acid at ambient conditions. The size and morphology of copper oxalate nanoparticles powder were studied by transmission and scanning electron microscopy.

Noise effect on soliton phenomena in fractional stochastic Kraenkel-Manna-Merle system arising in ferromagnetic materials.

This work dives into the Conformable Stochastic Kraenkel-Manna-Merle System (CSKMMS), an important mathematical model for exploring phenomena in ferromagnetic materials. A wide spectrum of stochastic soliton solutions that include hyperbolic, trigonometric and rational functions, is generated using a modified version of Extended Direct Algebraic Method (EDAM) namely r+mEDAM. These stochastic soliton solutions have practical relevance for describing magnetic field behaviour in zero-conductivity ferromagnets.

Hydrogen Sulfide Adsorption from Natural Gas Using Silver-Modified 13X Molecular Sieve.

The removal of hydrogen sulfide from natural gas and other gases such as biogas, refinery gases, and coal gas is required because it is toxic and corrosive, even in traces. Zeolites are widely used in the removal of HS from the abovementioned gases. In this work, we prepared an Ag-exchanged 13X molecular sieve by using different concentrations of AgNO to increase its adsorption properties.

Thermal-hydraulic characteristics of nitric acid: An experimental and numerical analysis.

Nitric acid is one of the most important products in the chemical industry, ranking third globally in terms of acid production. Although nitric acid has many industrial applications, its primary function is the production of ammonium nitrate, which is used in the fertilizer industry. In this report, we propose a plan for an Ostwald process plant that will produce 1000 metric tons of nitric acid per day.

Approximation of electrical double-layer thickness in hydrocarbon systems flowing through the pores of reservoir rocks.

In porous systems, such as in oil reservoir rock formations, the double layers from opposite sides of the pores may overlap if the pore size is narrow. This overlap is relatively likely to occur under low-electrolyte concentrations, such as those in crude oil, thus markedly affecting the electrokinetic measurements. This article evaluates the effects of overlap of the diffuse layers in the narrow capillaries of the reservoir rock cores in oils.

Asphaltene Remediation and Improved Oil Recovery by Advanced Solvent Deasphalting Technology.

Resin molecules play a crucial role in the stability of colloidal asphaltene particles in petroleum reservoirs. De-stabilization of the asphaltene/resin interaction due to changes in thermodynamic parameters can cause asphaltene precipitation, thus leading to petroleum field problems such as decreased in situ permeability, as well as severe plugging problems in production facilities. One remedial technology used in the oil industry involves developing synthetic resins with enhanced chemical potential to increase the stability of asphaltene in the oil phase.

Boundary effects on the streaming flow around a bubble located at the velocity antinode of a standing wave.

This study uses the singular perturbation method to analyze the streaming flow around a pulsating bubble at the velocity antinode of a standing wave. The bubble radially and laterally oscillates with small nondimensional amplitudes of ε` and ε, respectively. The momentum equation is expanded using ε.

Synthesis of mesoporous Ag/α-FeO/TiO heterostructures with enhanced and accelerated photo/-catalytic reduction of 4-nitrophenol.

4-Nitrophenol (4-NP) is reported to originate disadvantageous effects on the human body collected from industrial pollutants; therefore, the detoxification of 4-NP in aqueous contamination is strongly recommended. In this study, the heterojunction mesoporous α-FeO/TiO modulated with diverse Ag percentages has been constructed via a sol-gel route in the occurrence of a soft template P123. The formation of biphasic crystalline TiO anatase and brookite phases has been successfully achieved with the average 10 nm particle sizes.

On-substrate fabrication of a self-activated nanostructured ZnO gas sensor.

Gaining rational control over bottom-up device fabrication processes is necessary to achieve high-performance devices and overcome technical obstacles. Among these is the need for activation of metal oxide gas sensors (GSs) by an external heating source, which limits their miniaturization and integration. A well-controlled, seedless, and position-selective hydrothermal method to fabricate high-performance self-activated zinc oxide (ZnO) nano-needle (ZNN) GSs directly on a substrate was developed.

Impact of Surface Roughness on Flow Physics and Entropy Generation in Jet Impingement Applications.

In this paper, a numerical investigation was performed of an air jet incident that normally occurs on a horizontal heated plane. Analysis of flow physics and entropy generation due to heat and friction is included using a simple easy-to-manufacture, surface roughening element: a circular rib concentric with the air jet. This study shows how varying the locations and dimensions of the rib can deliver a favorable trade-off between entropy generation and flow parameters, such as vortex generation and heat transfer.

Novel Permanent Magnetic Surface Work Hardening Process for 60/40 Brass.

Surface work hardening is a process of deforming a material surface using a thin layer. It hardens and strengthens the surface while keeping the core relatively soft and ductile to absorb stresses. This study introduces a permanent magnate surface work hardening under two opposite permanent poles of a magnet to investigate its influence on a brass surface.

Vitamin D/vitamin K/magnesium-loaded polylactic acid/tricalcium phosphate/polycaprolactone composite nanofibers demonstrated osteoinductive effect by increasing Runx2 via Wnt/β-catenin pathway.

Vitamin D, vitamin K, and Mg (10%, 1.25%, and 5%, w/w, respectively)-loaded PLA (12%, w/v) (TCP (5%, w/v))/PCL (12%, w/v) 1:1 (v/v) composite nanofibers (DKMF) were produced by electrospinning method (ES) and their osteoinductive effects were investigated in cell culture test. Neither pure nanofibers nor DKMF caused a significant cytotoxic effect in fibroblasts.

Theoretical Investigation of Vapor Transport Mechanism Using Tubular Membrane Distillation Module.

This paper's primary objective is to examine the vapor delivery mechanism through a tubular membrane distillation (MD) module. Experiments were conducted utilizing a hydrophobic tubular membrane module with a pore size of 0.2 µm.

Mathematical Modeling and Analysis of Distributed Energy Systems for a Refinery in Kuwait.

In this study, a model is developed to optimally integrate various energy generation technologies within a refinery to help reduce economic costs as well as mitigate carbon emissions. The combined heat and power system was found to reduce 80 Mton of CO emissions while saving $2.61 billion dollars over 30 years as opposed to utilizing boilers and grid-connected electricity.

Estimation and Optimization of Tool Wear in Conventional Turning of 709M40 Alloy Steel Using Support Vector Machine (SVM) with Bayesian Optimization.

Cutting tool wear reduces the quality of the product in production processes. The optimization of both the machining parameters and tool life reliability is an increasing research trend to save manufacturing resources. In the present work, we introduced a computational approach in estimating the tool wear in the turning process using artificial intelligence.

Characteristics and health risk assessment of heavy metal contamination from dust collected on household HVAC air filters.

Heavy metals associated with airborne particulate matter are detrimental to human health, but risk assessment is difficult due to the technical challenges of determining exposure rates. In houses and other buildings, the heating, ventilation and air conditioning (HVAC) system is equipped with an air filter that captures airborne particulate matter from the indoor air that enters the HVAC system. This study used the air filter dust as a proxy for the heavy metal exposure of children and adults, based on a household study in Kuwait.

Accelerated diabetic wound healing by topical application of combination oral antidiabetic agents-loaded nanofibrous scaffolds: An in vitro and in vivo evaluation study.

The combination of oral antidiabetic drugs, pioglitazone, metformin, and glibenclamide, which also exhibit the strongest anti-inflammatory action among oral antidiabetic drugs, were loaded into chitosan/gelatin/polycaprolactone (PCL) by electrospinning and polyvinyl pyrrolidone (PVP)/PCL composite nanofibrous scaffolds by pressurized gyration to compare the diabetic wound healing effect. The combination therapies significantly accelerated diabetic wound healing in type-1 diabetic rats and organized densely packed collagen fibers in the dermis, it also showed better regeneration of the dermis and epidermis than single drug-loaded scaffolds with less inflammatory cell infiltration and edema. The formation of the hair follicles started in 14 days only in the combination therapy and lower proinflammatory cytokine levels were observed compared to single drug-loaded treatment groups.

Predicting the Tool Wear of a Drilling Process Using Novel Machine Learning XGBoost-SDA.

Tool wear negatively impacts the quality of workpieces produced by the drilling process. Accurate prediction of tool wear enables the operator to maintain the machine at the required level of performance. This research presents a novel hybrid machine learning approach for predicting the tool wear in a drilling process.

Surface Evaluation of a Multi-Pass Flexible Magnetic Burnishing Brush for Rough and Soft Ground 60/40 Brass.

Burnishing is an advanced finishing process that produces higher-quality surfaces with better hardness and roughness than conventional finishing processes. Herein, a flexible magnetic burnishing brush comprising stainless steel pins under permanent magnet poles was used to investigate the influence of multiple passes and directions on the produced surface of soft and rough ground prepared brass. In total, five different samples were burnished on each of the two brass samples prepared.

A novel reusable anti-COVID-19 transparent face respirator with optimized airflow.

This novel face mask is designed to be a reusable respirator with a small and highly efficient disposable fabric filter. Respirator material requirements are reduced by 75% compared to traditional designs and allow repeated cleaning or sterilization. The probability of virus particle inhalation is reduced using novel air filtration pathways, through square-waveform design to increase filter airflow.