Effects of electrolysis on magnetic abrasive finishing of AA6063-T1 tube internal surface using combination machining tool

In this research, we studied the effects of electrolysis in the magnetic abrasive finishing of an AA6063-T1 tube internal surface. The finishing surface‘s hairline morphology was removed in a short time by physical characteristic transformation of the finishing surface in which the aluminum oxide film was formed during the electrolysis. Next, magnetic abrasive finishing was used to eliminate the oxidation layer and polish the surface to a mirror-finishing standard. The two-step process effectively improved the surface roughness in a shorter time. The morphology changes before and after the finishing process, was studied by surface roughness measurement and scanning electron microscope photographs. Notably, the pit or micro holes formation during the electrolysis on the aluminum oxide film was examined and its effect on the surface roughness was studied. The elements’ residual on the surface was investigated by X-ray photoelectron spectroscopy analyzer before and after the process to confirm the formation and removal of oxidation film on the finishing surface. The lower value for torque measurement in electrolysis combined process compared to the conventional method was due to the porous characteristic of aluminum oxide film

N95 respirator hybrid decontamination method using Ultraviolet Germicidal Irradiation (UVGI) coupled with Microwave-Generated Steam (MGS).

The Coronavirus Disease 2019 (COVID-19) pandemic has induced a critical supply of personal protective equipment (PPE) especially N95 respirators. Utilizing respirator decontamination procedures to reduce the pathogen load of a contaminated N95 respirator can be a viable solution for reuse purposes. In this study, the efficiency of a novel hybrid respirator decontamination method of ultraviolet germicidal irradiation (UVGI) which utilizes ultraviolet-C (UV-C) rays coupled with microwave-generated steam (MGS) against feline coronavirus (FCoV) was evaluated. The contaminated 3M 1860 respirator pieces were treated with three treatments (UVGI-only, MGS-only, and Hybrid-UVGI + MGS) with variable time. The virucidal activity was evaluated using the TCID50 method. The comparison of decontamination efficiency of the treatments indicated that the hybrid method achieved at least a pathogen log reduction of 4 logs, faster than MGS and UVGI. These data recommend that the proposed hybrid decontamination system is more effective comparatively in achieving pathogen log reduction of 4 logs

A review on friction stir butt welding of aluminum with magnesium: A new insight on joining mechanisms by interfacial enhancement

The growing demand for lightweight materials in the automotive and aerospace industries has driven research on joining dissimilar lightweight alloys, particularly Al and Mg alloys (Al/Mg). Friction stir welding (FSW) is a promising technique for joining Al/Mg alloys, as it works below the base metal's melting temperature, leading to refined microstructures, reduced porosity, and enhanced productivity. The strength of Al/Mg friction stir weldment depends on the evolved interface, which is primarily characterized by micromechanical interlocks, type, and intermetallic compounds (IMCs) distribution. Different interfaces for butt joints have been discussed in the literature. However, the mechanism of interfacial interaction together with the ways to enhance the interface have not been reviewed yet. This review article fills the gap by analyzing the retrospective data for process parameters and mechanical properties. Joining mechanisms and the evolution of different interfaces at the microstructural level have been discussed. Lastly, ways to enhance the interface for improved mechanical properties are explained. By offering essential insights into FSW techniques and Al/Mg weld interfaces, this review article paves the way for developing FSW procedures for Al/Mg butt welds aiming for enhanced strength and performance. This review article is expected to be of interest to researchers and engineers working in the field of FSW, particularly for Al/Mg lightweight applications. It provides an overview of the current state of knowledge and identifies key areas for future research

Assessment of fatigue and corrosion fatigue behaviours of the nitrogen ion implanted CpTi

The fatigue and corrosion fatigue behaviours of commercially pure titanium (CpTi) have been particularly studied because the requirements of titanium (Ti) base materials are widely used for biomedical applications. The optimal properties of CpTi surface can be preserved by nitrogen ion implantation at a certain dose and energy. Still the fatigue and corrosion fatigue behaviours of nitrogen ion implanted CpTi (Nii-Ti) must be verified. This study performs the fatigue tests for CpTi and Nii-Ti specimens in a laboratory air and the corrosion fatigue tests for Nii-Ti specimens in a saline solution. Effects of nitrogen ion implantation on surface properties can improve the fatigue strength, fatigue life and corrosion fatigue life of Ti base materials. The corrosion pit growth law has been established on the basis of empirical data for predicting the corrosion penetration rate to estimate to the service life of Nii-Ti

Decontamination Methods of N95 Respirators Contaminated with SARS-CoV-2

In the preparation and response to the COVID-19 pandemic, a sufficient supply of personal protective equipment (PPE), particularly the face mask, is essential. Shortage of PPE due to growing demand leaves health workers at significant risk as they fight this pandemic on the frontline. As a mitigation measure to overcome potential mask shortages, these masks could be decontaminated and prepared for reuse. This review explored past scientific research on various methods of decontamination of the N95-type respirators and their efficiency against the SARS-CoV-2 virus. Ultraviolet germicidal irradiation (UVGI) and hydrogen peroxide vapor (HPV) show great potential as an effective decontamination system. In addition, UVGI and HPV exhibit excellent effectiveness against the SARS-CoV-2 virus on the N95 respirator surfaces

Subsurface Flow Phytoremediation Using Barley Plants for Water Recovery from Kerosene-Contaminated Water: Effect of Kerosene Concentration and Removal Kinetics

A phytoremediation experiment was carried out with kerosene as a model for total petroleum hydrocarbons. A constructed wetland of barley was exposed to kerosene pollutants at varying concentrations (1, 2, and 3% v/v) in a subsurface flow (SSF) system. After a period of 42 days of exposure, it was found that the average ability to eliminate kerosene ranged from 56.5% to 61.2%, with the highest removal obtained at a kerosene concentration of 1% v/v. The analysis of kerosene at varying initial concentrations allowed the kinetics of kerosene to be fitted with the Grau model, which was closer than that with the zero order, first order, or second order kinetic models. The experimental study showed that the barley plant designed in a subsurface flow phytoremediation system would have great potential for the reclamation of kerosene-contaminated water

Simultaneous Adsorption of Ternary Antibiotics (Levofloxacin, Meropenem, and Tetracycline) by SunFlower Husk Coated with Copper Oxide Nanoparticles

In this study, a new adsorbent derived from sunflower husk powder and coated in CuO nanoparticles (CSFH) was investigated to evaluate the simultaneous adsorption of Levofloxacin (LEV), Meropenem (MER), and Tetracycline (TEC) from an aqueous solution. Significant improvements in the adsorption capacity of the sunflower husk were identified after the powder particles had been coated in CuO nanoparticles. Kinetic data were correlated using a pseudo-second-order model, and was successful for the three antibiotics. Moreover, high compatibility was identified between the LEV, MER, and TEC, isotherm data, and the Langmuir model, which produced a better fit to suit the isotherm curves. In addition, the spontaneous and exothermic nature of the adsorption process was crucial for transforming the three antibiotics into CSFH. The greatest CSFH adsorption capacity was in MER (131.83 mg/g), followed by TEC (96.95 mg/g), and LEV (62.24 mg/g). These findings thus indicate that CSFH is one of the most effective and efficient adsorbents to use for eliminating wastewater contaminated with antibiotic residue