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Article
Publication date: 8 September 2012

Hassan S. Emira, Alia A. Shakour, Sayed S. Abd El Rehim, Inas A. Saleh and Mohammed A. El‐Hashemy

The paper aims to evaluate the anti‐corrosion performance of inorganic pigments included in paint systems based on plasticized‐chlorinated rubber for carbon steel in…

Abstract

Purpose

The paper aims to evaluate the anti‐corrosion performance of inorganic pigments included in paint systems based on plasticized‐chlorinated rubber for carbon steel in different environmental conditions.

Design/methodology/approach

Paint systems based on chlorinated rubber and inorganic pigments such as zinc chromate, zinc phosphate, red iron oxide and treated iron industry waste powder were prepared. Immersion in 3.5 percent salt solution, as well as outdoor exposure tests, were performed and the paint physico‐mechanical properties were tested to evaluate the paints' anti corrosive performance.

Findings

The concentration and the type of pigments included in the prepared paint systems control their anticorrosive performance.

Originality/value

The paper demonstrates how pigment consisting of treated iron industry waste powder could be used in anticorrosion paints for carbon steel.

Details

Anti-Corrosion Methods and Materials, vol. 59 no. 5
Type: Research Article
ISSN: 0003-5599

Keywords

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Article
Publication date: 17 May 2013

Nivin M. Ahmed, Hassan S. Emira and Hesham M. Tawfik

Ion‐exchange clays containing sodium such as bentonite and montmorillonite have the ability to exchange their cations. Few studies conducted with this type of ion‐exchange…

Abstract

Purpose

Ion‐exchange clays containing sodium such as bentonite and montmorillonite have the ability to exchange their cations. Few studies conducted with this type of ion‐exchange pigments are not conclusive about their anticorrosive efficiency. The present research aims to address the study on the anticorrosive efficiency of this type of pigments in chlorinated rubber paints. Sodium‐bentonite was exchanged with Zn, Sr and Zn‐Sr to be applied on low carbon steel specimens and study the anticorrosive performances of these new ion‐exchanged bentonites (IEBs) in anticorrosive paint formulations.

Design/methodology/approach

The new pigments were characterised using scanning electron microscopy (SEM) and X‐ray fluorescence (XRF) to determine the CEC (cation exchange capacity) of the different exchanged cations. Evaluation of the ion‐exchanged and Na‐bentonite pigments using international standard testing methods (ASTM) was estimated. Paint systems manufactured with these ion‐exchange pigments have been subjected to adhesion, accelerated corrosion laboratory tests, and EIS in order to assess their anticorrosive behaviour.

Findings

The results of this work revealed that the ion‐exchange bentonite (IEBs) pigments showed high anticorrosive performance that can be arranged as follows: Sr‐bentonite was better than Zn‐Bentonite and both were better than the double Zn‐Sr‐bentonite indicating an antagonism behaviour between the two cations when present together.

Practical implications

These pigments can be applied in other polymer composites, e.g. rubber and plastics as reinforcing agent and fillers.

Originality/value

These prepared pigments are environmentally friendly pigments which impart high anticorrosive behaviour to paint films with great economic savings.

Details

Pigment & Resin Technology, vol. 42 no. 3
Type: Research Article
ISSN: 0369-9420

Keywords

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Article
Publication date: 22 March 2011

Nivin M. Ahmed, Hassan S. Emira and Mohamed M. Selim

Organic coatings remain the most widely used way of protecting steel structures from corrosion. Traditional anticorrosive paints contain lead or hexavalent chromium…

Abstract

Purpose

Organic coatings remain the most widely used way of protecting steel structures from corrosion. Traditional anticorrosive paints contain lead or hexavalent chromium compounds as active pigments. The use of these classical chromates is nowadays restricted by increasing environmental awareness and stringent national and international regulations. An alternative is the use of ion‐exchangeable pigments. The purpose of this paper is to show that cation‐exchanged zeolites can be considered as a safe and efficient alternative to traditional hazardous pigments in protecting steel surfaces.

Design/methodology/approach

The new pigments were characterised using different analytical and spectro‐photometric techniques. Characterisation of these pigments using X‐ray diffraction and scanning electron microscopy were done. X‐ray fluorescence was employed to elucidate the concentration of different elements in the prepared pigments. Evaluation of the ion‐exchanged and initial zeolite pigments using international standard testing methods (ASTM) was estimated. Testing the anticorrosive protection of cation‐exchanged zeolites in alkyd paints formulated based on their pigment volume concentration/critical pigment volume concentration was studied, and then these new pigments were applied on cold‐rolled steel panels. The physico‐mechanical properties of dry films and their corrosion properties using accelerated laboratory test in 3.5 per cent NaCl for 28 days were tested.

Findings

The results of this work revealed that paint films containing initial Na‐zeolite performed the least protection behaviour, while films including Zn, Ca and Mg‐zeolites were better in their corrosion protection performance, and they can be arranged as Zn‐zeolite>Ca‐zeolite>Mg‐zeolite.

Practical implications

These pigments can be applied in other polymer composites, e.g. rubber and plastics as reinforcing agent and fillers.

Originality/value

The paper shows that these prepared pigments are environmentally friendly pigments which impart high anticorrosive behaviour to paint films with great economic savings.

Details

Pigment & Resin Technology, vol. 40 no. 2
Type: Research Article
ISSN: 0369-9420

Keywords

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Article
Publication date: 19 May 2012

Hassan S. Emira, Alia A. Shakour, Sayed S. Abd El Rehim, Inas A. Saleh and Mohammed A. El‐Hashemy

The purpose of this paper is to report the use of zinc phosphate pigment as a chromate substitute for coatings on non‐ferrous metals (galvanized steel, pure aluminum…

Abstract

Purpose

The purpose of this paper is to report the use of zinc phosphate pigment as a chromate substitute for coatings on non‐ferrous metals (galvanized steel, pure aluminum, α‐brass and pure copper).

Design/methodology/approach

Paint systems based on zinc chromate and zinc phosphate pigments were prepared. The paints were tested for their physico‐mechanical properties. Testing of the anticorrosive properties of the zinc phosphate pigment in comparison with zinc chromate pigment was carried out by accelerated corrosion exposure, i.e. immersion in 3.5 percent salt solution and exposure for one year at five outdoor stations.

Findings

The possibility of replacing chromate pigment was assessed and the “gap“ observable between the performance of zinc chromate and zinc phosphate pigments was noted.

Originality/value

The non‐toxic inhibitive pigment, zinc phosphate, incorporated into a plasticized‐chlorinated rubber binder, could be applied successfully for the protection of non‐ferrous substrates.

Details

Anti-Corrosion Methods and Materials, vol. 59 no. 3
Type: Research Article
ISSN: 0003-5599

Keywords

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Article
Publication date: 30 August 2013

Hassan Salah Aly Emira, Yosreya Mostafa Abu‐Ayana and Sanaa Mohammad El‐Sawy

The purpose of this paper is to study the corrosion protective properties of modified urea and/or thiourea formaldehyde resins for steel surface.

Abstract

Purpose

The purpose of this paper is to study the corrosion protective properties of modified urea and/or thiourea formaldehyde resins for steel surface.

Design/methodology/approach

Three butyl alcohol modified amino resins were laboratory prepared. The three modified resins were characterized using thermal gravimetric analysis and infrared; the solid content and refractive index of each were also measured.

Findings

The resins that contain both nitrogen and sulphur have excellent corrosion inhibitive activity compared with that containing nitrogen only.

Research limitations/implications

The modified resins were based on urea formaldehyde resin, mixed urea and thiourea formaldehyde resin and thiourea formaldehyde resin, respectively.

Practical implications

The prepared resins were introduced in different coating formulations based on short‐oil alkyd resin, medium‐oil alkyd resin and plasticized chlorinated rubber. They were then tested and evaluated for corrosion protection of steel surfaces.

Originality/value

All the prepared resins show promising results for corrosion protection of steel surfaces.

Details

Pigment & Resin Technology, vol. 42 no. 5
Type: Research Article
ISSN: 0369-9420

Keywords

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Article
Publication date: 28 June 2013

Fawzia Fahim Abdel‐Mohsen and Hassan Salah Aly Emira

This work aimed to prepare black transition metal oxide pigments to be used as solar absorbers in the solar selective and other industrial paints.

Abstract

Purpose

This work aimed to prepare black transition metal oxide pigments to be used as solar absorbers in the solar selective and other industrial paints.

Design/methodology/approach

Mixed metal oxide CoCuMnOx spinel pigments were synthesised via the sol‐gel route. These oxides, namely (I‐Co0.50Cu0.25Mn0.25)Ox, (II‐Co0.25Cu0.50Mn0.25)Ox and (III‐Co0.25Cu0.25Mn0.50)Ox, were prepared with different molar ratios and annealed at 600, 800 and 900°C, respectively. The prepared oxides were characterised by infrared spectrometer (IS), differential scanning calorimetry analysis (DSC), X‐ray diffraction (XRD) and transmission electron microscope (TEM).

Findings

The prepared pigments have a spinel structure with the composition CoCuMnOx. All synthesised pigments consisted of nano particles ranged from 10 to 80 nm. The optical properties showed high absorption and moderately low reflectance in the solar wavelength range.

Research limitations/implications

The prepared samples, used in the present work, were synthesized from cobalt sulphate, copper chloride and manganese chloride. The salts were dispersed in polyacrylamide as a precursor.

Practical implications

The prepared samples were thermally stable and had good optical properties. They could be used as absorber materials in the painting of solar collectors.

Originality/value

These thermally stable mixed metal oxides could be used in the painting of solar collectors. The three mixed metal oxides could be used as absorber materials for heating solar collectors due to their high absorption and moderately low reflectance in the solar wavelength range.

Details

Pigment & Resin Technology, vol. 42 no. 4
Type: Research Article
ISSN: 0369-9420

Keywords

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Article
Publication date: 2 November 2015

Fawzia Fahim Abdel-Mohsen and Hassan Salah Aly Emira

– The purpose of this study was to prepare colour pigments for use as spectrally selective coatings for solar absorbers.

Abstract

Purpose

The purpose of this study was to prepare colour pigments for use as spectrally selective coatings for solar absorbers.

Design/methodology/approach

Nano-particles cobalt and nickel oxides were prepared by sol–gel techniques. These oxides were prepared with its molar ratios and annealed at 200, 400, 600 and 800°C. The structure of the pigments was characterized by infrared spectrometer, differential scanning calorimetry analysis, X-ray diffraction, transmission electron microscope and scanning electron microscope.

Findings

Encapsulated cobalt and nickel oxides were completely formed at 800 and 600°C, and its colour was black and dark green, respectively. The results confirmed that black and green pigments combined selectivity with colour. Optical properties such as absorption and reflection were affected by the firing temperatures on cobalt and nickel oxides–gel polymers. All synthesized pigments consisted of nano-particles.

Research limitations/implications

The prepared samples used in the present work were synthesized from cobalt chloride and nickel acetate. The salts were dispersed in polyacrylamide as a precursor.

Practical implications

The prepared metal oxides had good solar properties.

Originality/value

Colour becomes more important for thermal solar collectors, and it has attracted interest. This might be related to a generally growing attention towards architectural integration of solar energy systems into building. Architects would prefer different colours besides black, even if lower efficiency would have to be accepted.

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Article
Publication date: 3 July 2018

Sarah Seleznyov

The purpose of this paper is to explore the popularity of Japanese lesson study (JLS) beyond Japan and the challenges this translation might pose. It notes that there is…

Abstract

Purpose

The purpose of this paper is to explore the popularity of Japanese lesson study (JLS) beyond Japan and the challenges this translation might pose. It notes that there is not a universally accepted definition of lesson study (LS) and seeks to identify the “critical components” of JLS through a review of the literature. It then uses a systematic literature review of recent studies of the implementation of LS with in-service teachers beyond Japan to analyse the models of LS used against these seven critical components in order to explore the degree of fidelity to the Japanese model.

Design/methodology/approach

A broad review of the literature on JLS available in the English language identifies seven “critical components”. A systematic literature review of 200 recent English language studies of the implementation of LS with in-service teachers beyond Japan is then carried out. Articles published between 2005 and 2015 are explored, including peer reviewed articles, scientific journals, book chapters and PhD dissertations. This systematic review enables an analysis of the models of LS used in studies from beyond Japan against the “seven critical components” of JLS.

Findings

The analysis shows that there is not an internationally shared understanding of Japanese lesson study (JLS) and that many of the missing components are those which distinguish LS as a research process, not simply a collaborative professional development approach. It also reveals that UK LS models seem particularly far from the Japanese model in those critical components which connect teachers’ knowledge and understanding within groups, to knowledge and understanding that exists beyond it. The study discusses whether these differences could be attributed to structural or cultural differences between Japan and other nations.

Research limitations/implications

The search for descriptions of the JLS is limited to articles available in the English language, which, therefore, represent a quite limited body of authority on the “critical components” of LS. The systematic review is similarly limited to English language articles, and there is a clear bias towards the USA, with the Far East and the UK making up the majority of the remaining studies. The study suggests that future research on LS beyond Japan should consider teachers’ attitudes towards the research elements of the process as well as their skills and confidence in carrying out research into practice.

Practical implications

The study strikes a note of caution for schools wishing to implement JLS as an approach to teacher professional development in the UK and beyond. Japan’s systemic approach has embedded LS experience and expertise into the education system, meaning a uniform approach to LS is much more likely. In addition, other systemic challenges may arise, for example, UK professional development time and resources is not designed with JLS in mind and may therefore require a significant reworking.

Originality/value

Whilst several systematic reviews of LS have explored its growth, geographical spread, impact and key features, this study provides a different perspective. It analyses whether and to what degree the “lesson study” models these studies describe align with the literature on JLS, and the implications of this for researchers and practitioners.

Details

International Journal for Lesson and Learning Studies, vol. 7 no. 3
Type: Research Article
ISSN: 2046-8253

Keywords

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