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1 – 5 of 5To develop new eco‐environmentally friendly surface treatments based on cerate compounds as alternatives to the process involving toxic chromates for the corrosion protection of…
Abstract
Purpose
To develop new eco‐environmentally friendly surface treatments based on cerate compounds as alternatives to the process involving toxic chromates for the corrosion protection of magnesium alloys.
Design/methodology/approach
A treatment process in which a surface was alkaline‐etched prior to ceria treatment is proposed. The process involves cleaning, etching in potassium hydroxide followed by treatment in ceria conversion coatings. The effect of surface preparation prior to ceria treatment on the corrosion resistance of AZ91D in 3.5 per cent NaCl solution was measured using AC impedance spectroscopy and DC polarization techniques. Surface examination was performed by scanning electron microscopy, energy dispersive X‐ray.
Findings
It was shown that the ceria treatment can be used as a localized corrosion inhibitor for alloy AZ91D in NaCl solution. The level of inhibition strongly depended on the cerium concentration. Moreover, ceria treatments improved the pitting corrosion resistance due to the formation of protective oxide films which act as a barrier to oxygen diffusion to the metal surface. According to the EIS and polarization measurements, alkaline etching in KOH is more effective in reducing the pitting corrosion of AZ91D than was HCl. It was shown that surface treatment in alkaline solution (KOH) prior to ceria treatments played an important role in inhibiting the active surface sites, rejecting the chloride ions from the surface and forming uniformly distributed oxide film.
Originality/value
Ceria conversion coatings seem very promising as alternatives to toxic chromating for the corrosion protection of magnesium alloys in NaCl solution.
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Abdel Salam Hamdy and D.P. Butt
The paper seeks to find out new eco‐environmentally friendly surface treatments based on vanadate compounds as alternatives to the process involving toxic chromates for the…
Abstract
Purpose
The paper seeks to find out new eco‐environmentally friendly surface treatments based on vanadate compounds as alternatives to the process involving toxic chromates for the corrosion protection of aluminium alloys.
Design/methodology/approach
A treatment process in which the surface was etched prior to vanadia treatment is being proposed. The process involves cleaning, etching in potassium hydroxide followed by treatment in vanadia prepared by sol‐gel method. The effect of surface preparation prior to vanadia treatment on the corrosion resistance of AA6061 T6 in 3.5 per cent NaCl solution was measured using AC impedance spectroscopy and DC polarization techniques. Surface examination was performed by scanning electron microscopy (SEM), energy dispersive X‐ray (EDS), X‐ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM).
Findings
It has been shown that the etching process prior to vanadia treatment enhanced formation of a uniformly distributed compact surface V‐rich Al‐oxide film of smooth appearance and inhibited the active surface sites and thereby preventing localized corrosion.
Originality/value
Vanadate conversion coatings seem very promising as alternatives to toxic chromating for the corrosion protection of aluminium alloys in NaCl solution.
Details
Keywords
Simran Kaur, Anil Panghal, M.K. Garg, Sandeep Mann, Sunil K. Khatkar, Poorva Sharma and Navnidhi Chhikara
The purpose of this paper is to review the nutritional and food value of pumpkin Cucurbita, along with different health benefits. Cucurbita (pumpkin) is an herbaceous vine, member…
Abstract
Purpose
The purpose of this paper is to review the nutritional and food value of pumpkin Cucurbita, along with different health benefits. Cucurbita (pumpkin) is an herbaceous vine, member of Cucurbitaceae family. It is an edible, heat-sensitive plant, which has an abundant amount of active compounds such as carotenoids, alkaloids, flavonoids, polyphenols, tannins, tocopherols, phytosterols and cucurbitacin, accounted for numerous health benefits, namely, antidiabetic, antioxidant, anticarcinogenic, hypotensive, hyper protective activities.
Design/methodology/approach
Major well-known bibliometric information sources such as Web of Science, Scopus, Mendeley and Google Scholar were searched with keywords such as nutrition value of Cucurbita, Cucurbita utilization, bioactive compounds of pumpkin, health benefits, processing, food formulations and current scenarios were chosen to obtain a large range of papers to be analyzed. A final inventory of 105 scientific sources was made after sorting and classifying them according to different criteria based on topic, academic field, country of origin and year of publication.
Findings
The comprehensive review of different literature, data sources and research papers seeks to find and discuss various nutritional benefits of pumpkin. It contains all necessary macro- and micro-nutrients, amino acids, vitamins, antioxidants and bioactive compounds with a relatively low amount of antinutrients. The recent upsurge in consumer interest for health-promoting products has opened up new vistas for plant products containing bioactive compounds in different food formulations.
Originality/value
This paper contains information regarding the chemical composition, nutritive value, phytochemical studies, pharmacological properties, bio-accessibility, food and industrial applications of pumpkin. Worldwide, pumpkin is used as food additive in various food products such as candy, weaning mix, corn grits, kheer, jam, crackers, bread, etc. Effect of different processing methods such as high temperature, pH, blanching, oven drying, freeze-drying to retain or minimize its losses in case of color, texture, flavor, and the carotenoids are of concern. The review paper highlights the nutritional, therapeutic, potential and processing attributes.
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