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Tropical buildings are subjected to many militating elements of climate, prominent amongst which are sunlight and rainfall. However, the geographic area in which the study was conducted has an additional influence from the Atlantic Ocean, which is just a few meters away from the buildings. The sea breeze is laden with high salt content that has adverse effects upon and reactions with the materials used for building finishes. In most cases, the outer skin/external surface of a building does not have any protection, due to its function as the protective layer. However, the influence of prevailing saline air in the present case differs from one part of the study location to another due to distance. The paper aims to discuss these issues.

The study considered two areas of the city, referred to as zones A and B, using a survey approach to obtain data for empirical analysis. Various correlations were evaluated and regression analysis was carried out on the survey findings. The mean behaviour of each zone was determined using the F-value of the results to qualify the performance of paint in service at each location. Data obtained during the study were evaluated using SPSS version 15.0 software. Data were also obtained from architects practicing in Lagos using a structured interview.

The results demonstrated that degradation of paint set in faster and repainting was required earlier in Zone A than was the case in Zone B, due to more aggressive impact of the saline air. The established research findings that stipulate five to seven years for maintenance of paint were found not to hold good in areas subjected to saline air.

The research was geared towards establishing the appropriate use of paint in saline-laden environments as compared to its use in other parts of a tropical region. Specifiers/architects, developers and property owners may understand better the implications of their choice. Manufacturers should endeavour to develop paint that will retard the deleterious effects of saline air.

This study is the first attempt to investigate analytically the impact of saline air on the maintenance requirements of painted structures in the tropical regions.

Painting of buildings predates civilization. The primary purpose was to add beauty or aesthetics to the built environment. It was also to showcase the level of civilization, taste and fashion drive of the people. However, modern findings have proved that paint (when applied as a finishing coat on buildings) can elongate the service life of such buildings due to some characteristic properties it contains and modern additives that are included at production stage. This paper aims to examine some of the properties inherent in paint through which resistance to failure and better performance is enhanced, aesthetics is maintained and maintenance is reduced. It also examines whether these qualities subsist in all environments. Particular attention is given to its resistance to the impact of saline air when used around the Atlantic Ocean.

The research adopted a qualitative and quantitative approach with empirical analysis in examining the performance of paint used in salt laden environment.

It shows that paint used in an environment where saline air and salt is prevalent begins to deteriorate after two years and requires repainting as against the established norm of five to seven years (5‐7) in areas that are not exposed to saline air. The impact of saline air is significant at p<0.01.

Maximum life span of current paint products in the area is determined to provide adequate information for the preparation of maintenance schedule for painted exterior. Paint with higher resistance to salt attack is required to enhance the longevity of painted exterior in areas at close proximity to sources of salt. Specifying current available paint for exterior finish will be uneconomical and non‐compatible with the principle of sustainability.

The authors made a fresh attempt at investigating the life's span of paint used as exterior finish in salt laden area around the Atlantic Ocean due to the peculiarity of the stresses of the tropical region on external finishes. It also compared the result with existing researches. Differences in paint performance are established.

Paint that is used as exterior finish is subject to the stresses of the climate. The factors of climate such as sun and rain are major source of quick deterioration of paint. The existence of saline air and endogenic salt in substrates in any environment will increase the rate of failure and frequency of repainting of building exterior wall. The purpose of this paper is to ascertain the difference in the frequency of repainting of exterior surface of buildings in areas at close proximity to the Atlantic Ocean and the hinterland.

The research adopted a survey method that involved the administration of structured questionnaire on 384 respondents to elicit data for analysis. SPSS 15.0 software was used to analyse the data. The study area is divided into two zones.

Paint of the same quality from the same manufacturer is found to perform differently. All defects that are caused by salt attack occur earlier in Zone B than Zone A. The frequency of repainting (maintenance) in Zone A is two years due to direct contact with the Atlantic Ocean and Zone B is four years because of the distance from the ocean.

This study enlightens the stakeholders in the building industry in the preparation of maintenance schedule for buildings in salty environment. It will also assist the architects in decision making during specifications of exterior finishes in such environments. The maintenance challenges of paint that is applied as exterior finish in salty environment is made clear.

It is a novel search into understanding the maintenance frequency of paint that is applied as exterior finish of buildings in areas with direct and indirect contact to salt attack.

In Sweden, the annual wastage due to corrosion is estimated at 200 million Kronor (approximately £14 million). The economic importance of this loss was recognised at an early stage, and in 1933 the Swedish Academy of Engineering Science set up a special Anti‐Corrosion Committee concerned with the study of corrosion protection through paints, metal coatings and oiling. The work of this committee provided the background for the Swedish contributions (reported in CORROSION TECHNOLOGY of July 1954) to the Scandinavian Corrosion Conference, held in Copenhagen in May 1954. In view of the general importance of the subject of corrosion, the Swedish journal, Teknisk Tidskrift has now devoted an entire issue (No. 44, 1954) to it. As the ground is much the same as that covered by the contributions to the conference already reported in these columns, only a brief summary of the latest contributions is here given.

GERMANY. Oxidation of refractory carbide alloys (hard metals). The effect of additions of tungsten, chromium and tantalum‐niobium on the oxidation rate and structure of the oxide layers was studied on samples of titanium carbide/cobalt bonded, and annealed at 800 to 1,100°C. for 75 hr. If these contain sufficient tungsten carbide to dissolve completely in titanium dioxide (rutile), the tungsten trioxide formed in oxidation, the rate of this latter decreases strongly owing to reduced ion diffusion. If, owing to the higher tungsten carbide content, the proportion of WO3 in the oxide layer becomes so high that the solubility limit for WO3 in TiO2 is exceeded, then CoTiO2, Co2TiO4 and C0WO4 occur in the oxide layer in addition to CoO and TiO2. This decreases oxidation velocity still more.

Titanium is distinguished by a comparatively low specific weight, high tensile strength, high corrosion resistance, high impact strength at low temperatures and good cold‐forming properties. The range of applications therefore comprises two main groups, one based on the combination of low weight and high strength, the other on the corrosion resistance of the metal.

LIGHTING FOR INDUSTRY. Lighting equipment may be a particular source of danger under some industrial conditions, due to abnormal corrosion, or to the risk of explosion or fire. The corrosion and fire hazards include flammable liquids, vapours and dusts and some means of protection should, of course, be adopted to ensure safety in normal operation and also under faulty conditions. Precautions should also be taken against any chemical agents present in the atmosphere, perhaps accentuated by weather or heat.

The first example of the use of zinc coatings in the solution of a problem of corrosion fatigue arose when wires for towing paravanes in sea‐water failed after comparatively short periods of service. These failures were caused by vibrations which set up cyclic stresses in the presence of sea‐water from which the wires were not adequately protected. Later research revealed that the joint effect of repeated stresses and corrosion acting together far exceeds the sum of the two effects taken singly. Not all cases of corrosion fatigue can be dealt with by zinc protection, but most would benefit from such a coating. This article explains the principles of corrosion fatigue, discusses the cathodic protection offered by zinc, and compares results obtained by electroplating, hot‐dip galvanizing, spraying, and painting with heavily zinc‐pigmented paints.

This paper is aimed to study natural convection in enclosures with curved (concave and convex) side walls for porous media via the heatline-based heat flow visualization approach.

The numerical scheme involving the Galerkin finite element method is used to solve the governing equations for several Prandtl numbers (Pr_m) and Darcy numbers (Da_m) at Rayleigh number, Ra_m = 10⁶, involving various wall curvatures. Finite element method is advantageous for curved domain, as the biquadratic basis functions can be used for adaptive automated mesh generation.

Smooth end-to-end heatlines are seen at the low Da_m involving all the cases. At the high Da_m, the intense heatline cells are seen for the Cases 1-2 (concave) and Cases 1-3 (convex). Overall, the Case 1 (concave) offers the largest average Nusselt number ( Nur¯) at the low Da_m for all Pr_m. At the high Da_m, Nur¯ for the Case 1 (concave) is the largest involving the low Pr_m, whereas Nur¯ is the largest for Case 1 (convex) involving the high Pr_m.

Thermal management for flow systems involving curved surfaces which are encountered in various practical applications may be complicated. The results of the current work may be useful for the material processing, thermal storage and solar heating applications

The heatline approach accompanied by energy flux vectors is used for the first time for the efficient heat flow visualization during natural convection involving porous media in the curved walled enclosures involving various wall curvatures.