Women and the HIV/AIDS Epidemic: The Issue of School Age Girls’ Awareness in Nigeria

This study was conducted to examine women and the HIV/AIDS epidemic: the issue of school age girls’ awareness in Nigeria information was elicited from 1,222 randomly selected regular under-graduate female students from the 11 faculties of the University of Lagos, Nigeria, with the use of a standardized structured questionnaire. Results of the major objective of the study, that is the level of HIV/AIDS awareness among female undergraduate students, showed a moderate level of awareness, including other specific objectives of age, level of study and marital status. In contrast, at the graduate level—the 600 level of study—medical students showed a high degree of awareness, and it was only divorce as a sub-variable of marital status that showed a low level of awareness. The paper then made some recommendations, that what is needed in Nigeria is to address the cultural, biological and socio-economic conditions contributing to women greater vulnerability to HIV/AIDS epidemic

METHOD FOR INHIBITING METAL CORROSION DURING ACID CLEANING OR PICKLING

A corrosion inhibitor composition , which includes i ) an aqueous alcohol base fluid , ii ) a mixture of at least three polysaccharides selected from carboxymethyl cellulose , gum arabic , pectin , a salt of alginic acid , chitosan , dextran , hydroxyethyl cellulose , and soluble starch , with each poly saccharide that is present in the mixture being present in an amount of 0.05 to 0.5 wt . % , based on a total weight of the corrosion inhibitor composition , iii ) silver nanoparticles , and iv ) a pineapple leaves extract . A method of inhibiting corrosion of metal during acid cleaning / pickling whereby the metal is treated with an acidic treatment fluid containing an acid and the corrosion inhibitor composition

CORROSION INHIBITOR COMPOSITION AND METHODS OF INHIBITING CORROSION DURING ACID PICKLING

A corrosion inhibitor composition , which includes i ) an aqueous alcohol base fluid , ii ) a mixture of at least three polysaccharides selected from carboxymethyl cellulose , gum arabic , pectin , a salt of alginic acid , chitosan , dextran , hydroxyethyl cellulose , and soluble starch , with each poly saccharide that is present in the mixture being present in an amount of 0.05 to 0.5 wt . % , based on a total weight of the corrosion inhibitor composition , iii ) silver nanoparticles , and iv ) a pineapple leaves extract . A method of inhibiting corrosion of metal during acid cleaning / pickling whereby the metal is treated with an acidic treatment fluid containing an acid and the corrosion inhibitor composition

Biopolymer Composites and Nanocomposites for Corrosion Protection of Industrial Metal Substrates

Corrosion is a critical problem that can be found in all industries worldwide. Corrosion is particularly serious in the petroleum industry, due to the large amounts of metallic based assets located throughout the entire supply chain. Annual costs of corrosion and its consequences are estimated to be 3 – 5 % of GDP for developed countries of the world. Corrosion mitigation strategies adopted by some industries include materials selection, coatings and linings, cathodic protection and the use of corrosion inhibitors amongst others. The use of biopolymers for corrosion protection of industrial metal substrates particularly as corrosion inhibitors has generated interest globally because they are considered as environmentally friendly in addition to the possession of multiple adsorption centres. However, it is found that most biopolymers studied function as moderate corrosion inhibitors. Some of the steps taken to offset this drawback include copolymerization, addition of substances to exert synergistic action as well as the incorporation of inorganic substances in nano-size into the biopolymer matrix in order to improve the corrosion inhibition performances of the biopolymers. The application of biopolymer composites and nanocomposites as anticorrosion materials has shown promising results and is believed to form metal chelate which could block metal surfaces from aggressive ions present in corrosive media. In this chapter, the application of composites and nanocomposites of biopolymers such as chitosan, carboxyl methylcellulose, gum Arabic, Xanthan gum for corrosion protection of industrial metal substrates in different corrosive media is discussed

Application of ginger and grapefruit essential oil extracts on the corrosion inhibition of mild steel in dilute 0.5 M H2SO4 electrolyte

Admixture of ginger and grapefruit essential oils (GPP) were studied for their corrosion inhibition properties on mild steel (MS) in 0.5 M H2SO4 solution by potentiodynamic polarization, open circuit potential measurement, electrochemical impedance spectroscopy, weight loss analysis and ATF-FTIR spectroscopy. Results from potentiodynamic polarization shows GPP significantly reduced the corrosion of MS from 8.430 mm/y at 0% GPP concentration to values between 1.979 mm/y and 0.565 mm/y. The corresponding inhibition efficiency values ranged from 76.52% to 93.5% and corrosion current density from 1.88 × 10−4 A/cm2 to 5.36 × 10−5 A/cm2. GPP displayed mixed-type inhibition at all GPP concentrations studied. The OCP plot at 0% GPP initiated at -0.495V compared to -0.443V and -0.451V at 1% and 3.5% GPP. At 9000s, the corresponding OCP values are -0.442V, -0.410V and -0.424V due to electropositive plot shift and passivation of MS surface at 1% and 3.5% GPP, though significant potential transients were present on the OCP plot at 1% GPP. The electrochemical impedance results indicate that the corrosion resistance of MS increased from 4.402 Ω cm2 to 99.318 Ω cm2 upon the addition of 3.5% GPP resulting in inhibition efficiency of 96%. Data from weight loss analysis shows decrease in corrosion rate from 184.48 mm/y to values between 8.94 mm/y and 6.25 mm/y. The corresponding inhibition efficiency values varies from 95.16% at 1% GPP to 96.61% at 3.5% GPP concentration. The ATF-FTIR results confirm the adsorption of GPP molecules on the surface of the carbon steel electrode

Corrosion resistance and passivation behavior of 3004 AlMnMg and 4044AlSi aluminum alloys in acid-chloride electrolytes

Corrosion resistance of 3004 and 4044 aluminium alloys (3004Al and 4044Al) in neutral chloride (0.5%–4.5% concentration), sulphate (0.00625M-0.1Mconcentration), and chloride-sulphate (0.00625MH2SO4/0.5%–4.5% chloride concentration) solutions was studied with potentiodynamic polarization, open circuit potential, cyclic polarization, and optical microscopy. Results show 4044Al exhibited higher resistance to general corrosion while 3004Al was more resistant to localized corrosion. Corrosion of 4044Al decreases with increase in chloride concentration while 3004 Al increases. Corrosion rate values for 3004Al and 4044Al in sulphate solution were generally similar between 0.061–0.395mmy−1 and 0.168–0.213mmy−1, respectively. In chloride-sulphate solution, corrosion rate of 3004Al increased from 0.130mmy−1 to 1.563mmy−1 at peak chloride concentration whereas the corrosion rate of 4044Al is near constant. The passive film on 4044Al is found to weaken significantly with increase in chloride concentration. Passivation values varied from 0.39 Vat 0.5% chloride concentration to 0.01 Vat 4.5% concentration while the potential at which stable pitting occurred increased. The passivation range values for 3004Al are relatively stable with respect to chloride concentration. Results from cyclic polarization experiments show the deterioration rate of both alloys in NaCl solution is subject to chloride concentration. The results show the alloys corrode at all NaCl concentrations (0.5%–4.5%) with the lowest pitting corrosion risk in 0.5% and 1.5%NaCl solutions. The highest pitting corrosion risk of the alloys occurred in 3.5% NaCl solution. Significant localized morphological deterioration is visible throughout the entirety of 4044Al relative to the adjacent Al alloy matrix compared to total surface deterioration on 3004Al

Chemical, Electrochemical, and Surface Morphological Studies of the Corrosion Behavior of the AZ31 Alloy in Simulated Body Fluid: Effect of NaOH and H2O2Surface Pretreatments on the Corrosion Resistance Property

Magnesium and its alloys have attracted attention for biomedical implant materials in dental and orthopedic applications because of their biodegradability and similar properties to human bones. The very high rate of degradation in the physiological systems is, however, a major setback to their utilization. Chemical modification is one of the approaches adopted to enhance the corrosion resistance property of Mg and its alloys. In this work, NaOH and H2O2were used as a pretreatment procedure to improve the corrosion resistance of the AZ31 Mg alloy in simulated body fluid (SBF). Advanced techniques such as dynamic electrochemical impedance spectroscopy (dynamic-EIS), atomic force microscopy, and optical profilometry were used in addition to the classical mass loss, hydrogen evolution, EIS, and polarization techniques to study the corrosion resistance property of the alloy in SBF for 30 h. Results obtained show that the surface treatment significantly enhanced the corrosion resistance property of the alloy. From dynamic-EIS at 30 h, the charge transfer resistance of the untreated AZ31 Mg alloy is 432.6 ω cm2, whereas 822.7 and 2617.3 ω cm2are recorded for NaOH- and H2O2-treated surfaces, respectively. H2O2is a better treatment reagent than NaOH. The mechanism of corrosion of both untreated and treated samples in the studied corrosive medium has been discussed. © 2022 American Chemical Society. All rights reserved

Olive leaves extract mediated zero-valent iron nanoparticles: synthesis, characterization, and assessment as adsorbent for nickel (II) ions in aqueous medium

Zero-valent iron nanoparticles (NZVI-NPs) possess significantly high surface area and volume ratio, and this unique surface characteristic has enhanced reactivity to their adsorption potential. In this work, a bio-matter (Olive leaves extract) is deployed as a nature-inspired reducing agent for the synthesis of NZVI-NPs. The particle size of NZVINPs has been determined using particle sizer. The NZVI-NPs are characterized using analytical and morphological techniques such as ultraviolet − visible spectroscopy (UV − vis), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction spectroscopy (XRD), scanning electron microscope (SEM), Brunauer–Emmett–Teller (BET), and Fourier transform infrared (FTIR) spectroscopy. The average crystalline size of NZVINPs are around 30–60 nm while maximum adsorption is at 225 nm. XRD spectrum shows two distinctive diffraction peaks at 25.40° and 42.50° corresponding to lattice plane value indexed at (200) and (222) planes of faced centered cubic (FCC). At optimized experimental conditions, NZVI-NPs show 97% removal efficiency of Ni+2 ions from aqueous solution. The equilibrium time has been found to be 55 min and the monolayer maximum adsorption capacity is 139.5 mg/g. Kinetically, Ni+2 ions adsorption has been modelled using various physical isotherms and the data best fitted Freundlich isotherm model and pseudo-first-order kinetic; revealing a maximum adsorption capacity of 139.5 mg/g at 25 ± 3 °C and pH of 6.5. Desorption tests affirm the possibility of recovering reasonable amount of NZVI-NPs after used. The specific surface area of the NZVI-NPs sample measured by BET analysis is 21.9967 m2/g indicating a high adsorption capacity

Synthesis and anticorrosion studies of 4-[(2- nitroacetophenonylidene)-amino]- antipyrine on SAE 1012 carbon steel in 15 wt.% HCl solution

A novel corrosion inhibitor, ((E)-1,5-dimethyl-4-((1-(3-nitrophenyl)ethylidene)amino)-2- phenyl-1,2-dihydro-3H-pyrazol-3-one) (DNPP) was synthesized in high yield by the condensation reaction of 4-aminoantipyrine with 2-nitroacetphenone derived from acetophenone as a starting material and characterized by FT-IR, 1H, and 13C NMR techniques. DNPP was tested against the corrosion of SAE 1012 carbon steel in 15 wt.% HCl solution using electrochemical and surface characterization techniques. Results obtained show that DNPP is effective in retarding the corrosion of SAE 1012 carbon steel. With 4 mM of DNPP, the charge transfer resistance of SAE 1012 in 15 wt.% HCl solution is raised from 17.42 to 140.50 Ω cm2 and the substrate surface is protected by 87%. The inhibition is through adsorption mechanism (mixed-adsorption type) and has been confirmed by SEM and EDAX results. Potentiodynamic polarization results reveal that DNPP acted as a mixed-type corrosion inhibitor. DNPP is a promising candidate for the formulation of an inhibitor cocktail for the strong acid environment