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This paper aims to study the effect of SiO2 nano‐particulates on the corrosion behaviour of Ni‐W/SiO2 nanocomposite coatings.
Abstract
Purpose
This paper aims to study the effect of SiO2 nano‐particulates on the corrosion behaviour of Ni‐W/SiO2 nanocomposite coatings.
Design/methodology/approach
Weight loss measurements, electrochemical measurements and scanning electron microscope were used to study the corrosion behaviour of Ni‐W/SiO2 nanocomposite coatings in NaCl solution.
Findings
The incorporation of SiO2 nano‐particulates into the Ni‐W alloy matrix significantly increased the corrosion resistance. The improvement in corrosion resistance was due to the SiO2 nano‐particulates acting as physical barriers to the corrosion process by filling in crevices, gaps and microscopic holes on the surface of the Ni‐W alloy.
Originality/value
This study highlights the use of nano‐particulates for the control of Ni‐W alloy coating corrosion and opens a new route for industry in the anti‐corrosion field.
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Keywords
Abstract
Purpose
This paper aims to introduce a novel approach to the fabrication of photoluminescent materials by coating rare earth aluminate luminescent materials on metallic substrates and a readily manufacturable light source with robust structure in the form of photoluminescent sphere (APS).
Design/methodology/approach
The clean and dried stainless steel sphere was sprayed with UH 2593, a white undercoat, the luminescent coating and the weather resistance coating in chronological order.
Findings
After adhered onto the stainless steel sphere, the peaks corresponding to the N-H stretching vibrations were changed. The intensity of free N-H stretching at 3,536 cm−1 dramatically decreased and the peak of hydrogen-bonded N-H stretching of PU moved to lower wavenumbers. The red shift of the infrared bands of functional groups was attributed to the strengthened hydrogen bonding. The hydrogen bonding interactions between the stainless steel substrates and the polyurethane coating endowed the APS with excellent adhesive property and also promoted the evenly distribution of the photoluminescent particles in the polymer coating matrix.
Practical implications
This approach can be applicable in the fabrication of the photoluminescent materials. The APS can be used as signs and guiding post in remote areas without sufficient electricity supply and in the seas and rivers with complicated hydrological conditions.
Originality/value
This approach has provided a method to produce tough and durable luminescent signs for remote areas and dangerous seas and explained the functional mechanism of the combined application of metallic materials and non-metallic materials.
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Ramakant Rana, Qasim Murtaza and R.S. Walia
In this study, the tri-bological behaviour of the un-coated and diamond coated tungsten carbide was evaluated using the pin-on-disc test rig. The same was also tested on a lathe…
Abstract
Purpose
In this study, the tri-bological behaviour of the un-coated and diamond coated tungsten carbide was evaluated using the pin-on-disc test rig. The same was also tested on a lathe machine tool. This paper aims to compare the tri-bological behaviour of coated tungsten carbide pin with un-coated tungsten carbide pin it also correlates the wear obtained from the two machines used.
Design/methodology/approach
Experiments were performed using L8 orthogonal array and results obtained on a pin-on-disc test rig under dry sliding process were optimized through a modern optimization technique i.e. genetic algorithm (GA). The response surface methodology model (L8 orthogonal array) formed the basis for the development of the GA model, which defines the conditions of minimum wear, minimum coefficient of friction and minimum surface roughness for the sliding process of the pin-on-disc test rig.
Findings
Implementation of the heuristic approach for optimization of input parameters for the combination of tool material used for the turning process. The initial approach involves tri-bological testing considering the same combination. The set of experiments further performed, inferred that the results were similar and that the diamond coating enhances the life of the tool.
Originality/value
Successfully synthesized the diamond coating on tungsten carbide tool material. Implantation of the heuristic approach, i.e. GA to tri-bological tests to identify the optimized level of input variables. Experimentation involves the tri-bological testing whose results were confirmed through performing experiments on the lathe machine tool.
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The coatings industry, as well as the chemical industry of which it is a part, is being subjected to stress. There are numerous ways to react to stress. One way to react to stress…
Abstract
The coatings industry, as well as the chemical industry of which it is a part, is being subjected to stress. There are numerous ways to react to stress. One way to react to stress is to prognosticate, and the coatings industry has not been without those who wish to forecast its future. To attempt to delve into the future is both interesting and important and, accordingly, in this report we shall examine some of these forecasts. But first let us review briefly the origin of the stress to which the coatings industry is being subjected.
L. Mathivanan and S. Radhakrishna
Describes the preparation and properties of heat‐resistant paints based on an epoxy blended with rhodorsil silicone resin. Studies the heat‐resistant properties as per ASTM…
Abstract
Describes the preparation and properties of heat‐resistant paints based on an epoxy blended with rhodorsil silicone resin. Studies the heat‐resistant properties as per ASTM standard (D 2485‐91). Also determines the properties of the liquid paint and coated metal panels. Assesses the thermal degradation of the coating both by electrochemical (potential vs time and EIS) and structural (SEM) means. Results reveal that the coating is stable up to 200°C on a mild steel surface and degradation takes place only beyond this temperature. Discusses the failure mechanism of the above coating in light of the experiment’s results.
This article attempts to tackle a fundamental methodological question in economics. The task is to investigate whether competing traditions in the history of economics are…
Abstract
This article attempts to tackle a fundamental methodological question in economics. The task is to investigate whether competing traditions in the history of economics are commensurable or not, that is, whether there is a firm ground on which a researcher could adjudicate the truth content of a theory. Thomas Kuhn in philosophy and Donald McClosky in economics among others are understood to advance the thesis that theories are incommensurable since there is no empirical ground to resort to in order to resolve disputes among traditions in economics. Karl Popper in philosophy and Mark Blaug in economics among others argue that theories are commensurable since there is a sharp and distinct criterion which could determine the scientific content of a theory. A more sophisticated version of Popper's falsificationism has been advanced in philosophy by Imre Lakatos and has been correspondingly followed in economics by Spiro Latsis, E. Roy Weintraub and others.
Jing Lin, Wei Wang, Xiufang Wen, Zhi‐Qi Cai, Pihui Pi, Da‐feng Zheng, Jiang Cheng and Zhuoru Yang
The purpose of this paper is to study thermal stability, curing kinetics and physico‐chemical properties of polyurethanes systems for application in in‐mould decoration (IMD) ink.
Abstract
Purpose
The purpose of this paper is to study thermal stability, curing kinetics and physico‐chemical properties of polyurethanes systems for application in in‐mould decoration (IMD) ink.
Design/methodology/approach
The thermal stability of three Polyurethane (Pu) systems A, B, C were evaluated by thermogravimetric analysis (TGA). The kinetic parameters of the curing reaction of Pu system C were calculated using non‐isothermal curing kinetics analysis, including the activation energy Ea, the reaction rate constant K(T), the reaction order n, the initial curing temperature (Ti), the peak temperature (Tp), and the finishing temperature (Tf). Additionally, physico‐chemical properties were also evaluated such as flexibility, impact resistance, pencil hardness, adhesive attraction and solvent resistance.
Findings
TGA showed that thermal decomposition temperature T5 (5 wt.% weight loss), T10 (10 wt.% weight loss) and Tend (decomposition termination temperature) of Pu system C was 344°C, 363°C, and 489°C, respectively. T5, T10, Tend increased by 77°C, 61°C, 4°C, respectively, and the char yield at 600°C increased by 25.1 wt.% comparing with Pu system B. Curing kinetics analysis showed that Ea of Pu system C was 62.29 KJ/mol, 65.98 KJ/mol and 65.95 KJ/mol by Kissinger, Flynn‐Wall‐Ozawa and Ozawa method, respectively. The order of the curing reaction (n=0.90) demonstrated that it was a complex reaction. Moreover, Pu system C exhibited good physico‐chemical properties. The results showed that Pu system C was suitable to apply into IMD ink.
Research limitations/implications
The TGA analysis, curing kinetics analysis and evaluation of physico‐chemical properties provided a simple and practical solution to study suitable resins for IMD ink application.
Practical implications
IMD ink for heat transfer printing technology is highly efficient, relatively low cost, clean and environmentally safe. It has been widely applied into medical and pharmaceutical products, electronic devices, telecommunication equipment, computer parts, appliance panels, automotive parts, etc.
Originality/value
In this paper, the thermal stability and curing kinetics of Pu for IMD ink are reported for the first time. The paper gives very interesting and important information about thermal stability, curing kinetics and properties of Pu coating system for IMD ink application.
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In 1976, amid the vastly greater celebrations of the bicentennial anniversary of the Declaration of Independence, there was the greatest orgy of historical nostalgia in the…
Abstract
In 1976, amid the vastly greater celebrations of the bicentennial anniversary of the Declaration of Independence, there was the greatest orgy of historical nostalgia in the history of economics, occasioned by the bi‐centenary of the Wealth of Nations. In addition to a veritable deluge of scholarly books, articles, pamphlets, conferences, and symposia, and also innumerable popular and ephemeral effusions, all the mass media were enlisted. There were countless magazine and newspaper articles, some radio and T.V. programs, at least one especially commissioned technicolor film and, for all I know, there may also have been bicentennial poems, paintings, sculptures, and choral symphones!
M. Bajpai, Sunita Seth, A.K. Saxena and Ashok Ranjan
Some thermally stable epoxy coatings have been developed using functional aminosl.ilanes viz, N‐[3‐(trimethoxysilyl) propyl] ethylenediamine and copolymer of aminopropylmethyl…
Abstract
Some thermally stable epoxy coatings have been developed using functional aminosl.ilanes viz, N‐[3‐(trimethoxysilyl) propyl] ethylenediamine and copolymer of aminopropylmethyl dimethylsiloxane in different ratio. It has been observed that use of silicon compounds invariably enhances the thermal stabililty, chemical resistance and corrosion resistance of epoxy coating. It has also been observed that silane bearing triethoxy group gave better adherence properities whereas silicone gave better thermal stability. The degradation kinetics showed that the reactions were of first order.
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Within the past few years a small but vigorous and expanding group of scholars has demonstrated a growing interest in business records, and within the next decade or so they and…
Abstract
Within the past few years a small but vigorous and expanding group of scholars has demonstrated a growing interest in business records, and within the next decade or so they and their disciples will present librarians and archivists with some unfamiliar problems. Even if the record keepers resist the demand that they should venture forth to convert the businessmen and gather in the archival harvest, they must necessarily acquaint themselves with the current and prospective uses of these materials. As the main demands will undoubtedly come from business historians, I shall begin by outlining the present status and future prospects of this discipline.