Antimicrobial Activity and Physicochemical Analysis of Bio-degradable Films from Cucurbita pepo and Musa paradisiaca

Cucurbita pepo and Musa paradisiaca can be considered as a large source of starch which makes it appropriate to be used for the preparation of bio-plastic material. In this study, biodegradable films from Cucurbita pepo and Musa paradisiaca were developed and investigated for their properties like pH, ash, moisture content, amylose content, biodegradability, and antimicrobial activity. 1,2,3-Propanetriol, gingelly oil, and agarose gel was used to reduce the brittleness of the developed starch- based bioplastic films. The investigation of films was done by Spectroscopic and Surface Analysis techniques. The developed bio- films showed substantial properties like less engorgement and insolubility in water which makes it worth a commercial viable product for food packaging.

Effect of DC Currents and Strain on Corrosion of X80 Steel in a Near-Neutral Environment

The corrosion behavior of X80 steel in a near-neutral soil-simulated solution under various DC stray currents and applied strains was investigated using electrochemical measurements (open circuit potential, linear polarization, and electrochemical impedance spectroscopy) and surface analysis techniques. Our results show that a DC stray current has a substantially greater effect on steel corrosion compared to applied strain. However, strain could slow down the corrosion rate in specific conditions by affecting the composition of corrosion products and the structure of the corrosion scale on the surface of the steel. Although the porosity of the corrosion scale of steel without an applied strain will increase with increasing DC currents, once strain is applied, the corrosion scale will become denser. Furthermore, both DC currents and strain can promote steel pitting, and the number and size of pitting holes will increase significantly with an increase in current densities.

Removal of Chromium(III) and Cadmium(II) Heavy Metal Ions from Aqueous Solutions Using Treated Date Seeds: An Eco-Friendly Method

The aim of the research was to prepare low-cost adsorbents, including raw date pits and chemically treated date pits, and to apply these materials to investigate the adsorption behavior of Cr(III) and Cd(II) ions from wastewater. The prepared materials were characterized using SEM, FT-IR and BET surface analysis techniques for investigating the surface morphology, particle size, pore size and surface functionalities of the materials. A series of adsorption processes was conducted in a batch system and optimized by investigating various parameters such as solution pH, contact time, initial metal concentrations and adsorbent dosage. The optimum pH for achieving maximum adsorption capacity was found to be approximately 7.8. The determination of metal ions was conducted using atomic adsorption spectrometry. The experimental results were fitted using isotherm Langmuir and Freundlich equations, and maximum monolayer adsorption capacities for Cr(III) and Cd(II) at 323 K were 1428.5 and 1302.0 mg/g (treated majdool date pits adsorbent) and 1228.5 and 1182.0 mg/g (treated sagai date pits adsorbent), respectively. It was found that the adsorption capacity of H2O2-treated date pits was higher than that of untreated DP. Recovery studies showed maximal metal elution with 0.1 M HCl for all the adsorbents. An 83.3–88.2% and 81.8–86.8% drop in Cr(III) and Cd(II) adsorption, respectively, were found after the five regeneration cycles. The results showed that the Langmuir model gave slightly better results than the Freundlich model for the untreated and treated date pits. Hence, the results demonstrated that the prepared materials could be a low-cost and eco-friendly choice for the remediation of Cr(III) and Cd(II) contaminants from an aqueous solution.

Advantages and Limitations of Surface Analysis Techniques on Plasma-Treated Arabidopsis thaliana Seeds

Surface characterization of plasma-treated seeds has made significant progress over the last decade. Most papers in the literature use scanning electron microscopy (SEM) and contact angle goniometry to investigate surface modifications. However, very few papers address the chemical modifications to the seed coat after plasma treatment. Here, a summary of the methods used to analyze plasma-treated seeds is presented, such as SEM, contact angle goniometry, energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). The results obtained on Arabidopsis thaliana Col-0 seeds and the limitations of these techniques are discussed. An experiment was designed in order to compare the relative advantages and limitations of these surface analysis techniques by investigating the separate effects of plasma, heat, and ozone on A. thaliana seeds.

Utilizing of (Zinc Oxide Nano-Spray) for Disinfection against “SARS-CoV-2” and Testing Its Biological Effectiveness on Some Biochemical Parameters during (COVID-19 Pandemic)—”ZnO Nanoparticles Have Antiviral Activity against (SARS-CoV-2)”

A newly synthesized zinc (II) oxide nanoparticle (ZnO-NPs) has been used as a disinfectant Nano-spray for the emerging corona virus (SARS-CoV-2). The synthesized obtained nanomaterial of (ZnO) was fully chemically characterized by using different spectroscopic analysis (FT-IR, UV and XRD) and surface analysis techniques. ZnO-Nps surface morphology and chemical purity has been investigated by transmission electron microscope (TEM), high resolution transmission electron microscope (HR-TEM), scanning electron microscopy (SEM) as well as energy dispersive X-ray analysis (EDX), Additionally Zeta potential and Zeta size distribution were measured and evaluated to confirm its nano-range scale. The synthesized Zno-NPs have been tested using 10% DMSO and ddH2O for estimation of antiviral activity against (SARS-CoV-2) by using cytotoxicity assay (CC50) and inhibitory concentration (IC50). The results revealed that (Zno-NPs) has high anti-SARS-CoV-2 activity at cytotoxic concentrations in vitro with non-significant selectivity index (CC50/IC50 ≤ 1). The current study results demonstrated the (ZnO-NPs) has potent antiviral activity at low concentration (IC50 = 526 ng/mL) but with some cytotoxic effect to the cell host by (CC50 = 292.2 ng/mL). We recommend using of (ZnO-NPs) as potent disinfectant against (SARS-Cov-2), but there are slight side effects on the cellular host, so we recommend more prospective studies on complexation of other compounds with (ZnO-NPs) in different concentrations to reduce its cellular toxicity and elevate its antiviral activity against SARS-CoV-2 activities.

Reliability of Neural Implants—Effective Method for Cleaning and Surface Preparation of Ceramics

Neural implants provide effective treatment and diagnosis options for diseases where pharmaceutical therapies are missing or ineffective. These active implantable medical devices (AIMDs) are designed to remain implanted and functional over decades. A key factor for achieving reliability and longevity are cleaning procedures used during manufacturing to prevent failures associated with contaminations. The Implantable Devices Group (IDG) at University College London (UCL) pioneered an approach which involved a cocktail of reagents described as “Leslie’s soup”. This process proved to be successful but no extensive evaluation of this method and the cocktail’s ingredients have been reported so far. Our study addressed this gap by a comprehensive analysis of the efficacy of this cleaning method. Surface analysis techniques complemented adhesion strengths methods to identify residues of contaminants like welding flux, solder residues or grease during typical assembly processes. Quantitative data prove the suitability of “Leslie’s soup” for cleaning of ceramic components during active implant assembly when residual ionic contaminations were removed by further treatment with isopropanol and deionised water. Solder and flux contaminations were removed without further mechanical cleaning. The adhesive strength of screen-printed metalisation layers increased from 12.50 ± 3.83 MPa without initial cleaning to 21.71 ± 1.85 MPa. We conclude that cleaning procedures during manufacturing of AIMDs, especially the understanding of applicability and limitations, is of central importance for their reliable and longevity.

Low-Voltage Polarization in AOT Solution to Enhance the Corrosion Resistance of Nitinol

In this work, the corrosion behavior of bare nitinol (NiTi) alloy in Ringer's solution containing different concentrations of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) was first studied in order to determine whether the surfactant acts as a corrosion inhibitor. Results of potentiostatic and potentiodynamic experiments allowed concluding that AOT is a pitting corrosion inhibitor for NiTi. In a second stage of this research work, NiTi was treated under potentiostatic control (2.00 V) for 1 h in 0.10 M AOT solutions of pH 8.4 and 12. Static and rotating electrodes were used. The influence exerted by this treatment on the passive behavior of the alloy was studied in Ringer's solution using different electrochemical and surface analysis techniques. The best anticorrosion performance was obtained using a rotating electrode and AOT solution of pH 8.4. The thin oxide layer grown potentiostatically consists of TiO2, while no Ni was found in the outermost layer. The presence of this oxide layer allows reducing the amount of Ni and Ti released at open circuit potential conditions and at very positive potentials where pitting corrosion of the bare alloy occurs.

The Protection Role of Cysteine for Cu-5Zn-5Al-1Sn Alloy Corrosion in 3.5 wt.% NaCl Solution

In this work, the corrosion mechanism of a Cu-5Zn-5Al-1Sn alloy was examined in a 3.5 wt.% NaCl solution. At the same time, the effect of a cysteine inhibitor was also investigated through a multi-analytical approach. Electrochemical results suggested that inhibition efficiency increased with the increase of cysteine concentration. From potentiodynamic polarization (PD) analysis, a decrease in corrosion current and corrosion potential shift toward a more negative direction was observed. The potential difference between the blank and inhibited surface was found to be 46 mV, which is less than 85 mV, revealing a mixed type inhibition effect of cysteine for the Cu-5Zn-5Al-1Sn alloy. The inhibition mechanism of cysteine (Cys) and the effect of alloying elements were investigated by fitting experimental impedance data according to a projected equivalent circuit for the alloy/electrolyte interface. A Langmuir adsorption isotherm was proposed to explain the inhibition phenomenon of cysteine on the Cu-5Zn-5Al-1Sn alloy surface. Surface morphology observation confirmed that the Cu-5Zn-5Al-1Sn alloy was damaged in 3.5 wt.% NaCl solution and could be inhibited by using the cysteine inhibitor. The impact of alloying elements on the corrosion mechanism was further examined by surface analysis techniques such as X-Ray photoelectron spectroscopy (XPS)/Auger spectra, the results of which indicated that the corrosion inhibition was realized by the adsorption of the inhibitor molecules at the alloy/solution interface.

Inhibition of Q235 Carbon Steel by Calcium Lignosulfonate and Sodium Molybdate in Carbonated Concrete Pore Solution

The inhibition effect and mechanism of a compound calcium lignosulfonate (CLS) and sodium molybdate inhibitors for Q235 carbon steel in simulated carbonated concrete pore solution (pH 11.5) with 0.02 mol/L NaCl are studied using electrochemical and surface analysis techniques. The results show that in carbonated simulated concrete pore (SCP) solution CLS and Na2MoO4 show a synergistic inhibition effect. The compound inhibitor can be defined as mix-type inhibitor. With 400 ppm CLS plus 600 ppm Na2MoO4, the pitting potential moves positively about 200 mV, and the inhibition efficiency reaches 92.67%. After 24 h immersion, the IE% further increases up to 99.2%. The surface analysis results show that Na2MoO4 could promote stability of the passive film, and the insoluble molybdenum compounds and CaO/Ca(OH)2, together with adsorbed CLS, deposit on the steel surface, forming a complex film. The compounded film effectively inhibits corrosion of the steel.