• Wind and Structures
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• v.16 no.4
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• pp.301-322
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• 2013

Recent major post-hurricane damage assessments in the United States have reported that the most common damages result from the loss of building roof coverings and subsequent wind driven rain intrusion. In an effort to look further into this problem, this paper presents a full-scale (Wall of Wind --WoW--) investigation of external and underneath wind pressures on roof tiles installed on a low-rise building model with various gable roofs. The optimal dimensions for the low-rise building that was tested with the WOW are 2.74 m (9 ft) long, 2.13 m (7 ft) wide, and 2.13 m (7 ft) high. The building is tested with interchangeable gable roofs at three different slopes (2:12; 5:12 and 7:12). The field tiles of these gable roofs are considered with three different tile profiles namely high (HP), medium (MP), and low profiles (LP) in accordance with Florida practice. For the ridge, two different types namely rounded and three-sided tiles were considered. The effect of weather block on the "underneath" pressure that develops between the tiles and the roof deck was also examined. These tests revealed the following: high pressure coefficients for the ridge tile compared to the field tiles, including those located at the corners; considerably higher pressure on the gable end ridge tiles compared to ridge tiles at the middle of the ridge line; and marginally higher pressure on barrel type tiles compared to the three-sided ridge tiles. The weather blocking of clay tiles, while useful in preventing water intrusion, it doesn't have significant effect on the wind loads of the field tiles. The case with weather blocking produces positive mean underneath pressure on the field tiles on the windward side thus reducing the net pressures on the windward surface of the roof. On the leeward side, reductions in net pressure to a non-significant level were observed due to the opposite direction of the internal and external pressures. The effect of the weather blocking on the external pressure on the ridge tile was negligible.

• Advances in materials Research
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• v.2 no.1
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• pp.65-75
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• 2013

Heterogeneous photocatalysis is a rapidly developing field in environmental engineering. It has a great potential to cope with the increasing pollution in the air. The addition of a photocatalyst to ordinary building materials such as tiles, concrete, paints, creates environmental friendly materials by which air pollution or pollution of the surface itself can be controlled and diminished. This work reports the results of the laboratory research, especially carried out towards air purifying action and self-cleaning measurements. In particular the research was focused on the study of the photocatalytic behavior of industrially prepared tiles produced starting from commercial micro-sized $TiO_2$. Air purification action has been investigated through NOx degradation tests. On the contrary, the degradation of pollution at the surface, also called as self-cleaning action, is verified by the degradation of two different organic dyes: Rhodamine B (red color) and Metanil yellow (yellow).

• Journal of Korea Multimedia Society
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• v.9 no.10
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• pp.1282-1295
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• 2006

This paper proposes a method of image tile mosaics to preserve detailed depiction of the source image. This method enhance the shortcoming of the previous mosaic methods that cannot express the detailed depiction because of the gap between tiles. Our method is implemented by the usage of image tiles to preserve detailed depiction of the source image, as well as the usage of 2-layered tiles to.eliminate the gap between tiles. The method suggested in this paper are composed of following process. First of all, the position of the upper layer tile is located through a centroidal voronoi diagram to which an edge avoidance technique is applied, and the position of the lower layer tile is calculated using Delaunay triangulation. Secondly, discover the size and direction field of the tile considering the relation between tiles. Thirdly, adopt a photomosaic technique to use the image tiles. At this time, the technique of multi-level indexing is used to accelerate the speed of image searching. Through above process, the gap between tiles is minimized against other methods and a mosaic image with a maximized detailed description is achieved.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.9
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• pp.623-629
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• 2012

The objective was to evaluate the quality of harvested rainwater of the roofing materials used and the presence of lichens/mosses on the roofing surface. This experiment was studied in the field where five pilot structures with different roofing materials (i.e., wooden shingle tiles, wooden shingle tiles (including mosses), concrete tiles, clay tiles [Gi-Wa] and slate tiles) were installed. As a result, the clay tiles [Gi-Wa] was found to be the most suitable for rainwater harvesting applications. It was due to the disinfection from ultraviolet light and high temperature according to characteristic of roofing materials. Comparison with quality of rainwater on that wooden shingle tiles with and without including mosses, which may affect the concentration of and wooden shingle tiles including mosses, mosses may affect concentration of TOC, nitrate, and sulfate. Additionally, the average concentration of asbestos was determined to be measured at $0.002/cm^3$ for the slate tiles. The value satisfied with it met the Ministry of Environment's Multi-use facility standard and Ministry of Labor's Office standard ($0.01/cm^3$).

• Journal of the Korean Society of Safety
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• v.6 no.4
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• pp.53-57
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• 1991

Engineers of building construction have made efforts to produce more convinient building of good quality through the development of technology and raw materials nowadaye. This study is conducted to recognize problems of exterior tiles through experiments on quality of tiles according to sizes, and to find out and Iecommend most suitaff sizes of tiles. The sizes which are used widely in Construction field are selected as,45$\times$45mm, 57$\times$87mm, 60$\times$108mm, 60$\times$187mm, 96$\times$200mm. Ready mixed compound are used as mortar and Compressed attachment method are used.

• Advances in environmental research
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• v.9 no.4
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• pp.285-294
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• 2020

Growth of any country rest in the consumption of industrial wastes for its infrastructure amenities. Countries like India positively desires a vital utilization of industrial waste resembling paper sludge in the construction industry to make various building materials. Also, it is the duty of all civil engineers or researchers to attach them in mounting new materials from the waste dumped as land fillings. In every construction project, about 70% of cost accounts for the procurement of materials. If this, can be minimized consequently the cost of construction will certainly be condensed. Research has established that the waste paper sludge can be reused in the construction field for a probable scope. The construction diligences munch through a massive quantity of non-renewable resources. On the additional dispense, more waste paper board sludge ends up in landfills or dumpsites than those recycled. Consequently, waste paper sludge for use as a construction material composes a step towards sustainable development. Keeping this in mind an endeavor has been made to utilize paper board sludge acquired from the paper board industry and used with several pozzolanic and cementitious materials for a specific purpose. The addition of paper sludge has been varied from 0% to 20% by weight of cement. The tests done with the samples expose that four samples showed significant outcomes with remarkable strength and durability properties which guide to move for the next phase of research for producing lightweight tiles.

• Journal of applied mathematics & informatics
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• v.17 no.1_2_3
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• pp.343-350
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• 2005

In this paper we prove two results about tilings of orthogonal polygons. (1) P be an orthogonal polygon with rational vertex coordinates and let R(u) be a rectangle with side lengths u and 1. An orthogonal polygon P can be tiled with similar copies of R(u) if and only if u i algebraic and the real part of each of its conjugates is positive; (2) Laczkovich proved that if a triangle $\Delta$ tiles a rectangle then either $\Delta$ is a right triangle or the angles of $\Delta$ are rational multiples of $\pi$. We generalize the result of Laczkovich to orthogonal polygons.

• Wind and Structures
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• v.17 no.2
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• pp.185-202
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• 2013

The goal of this study was to investigate the vulnerability of roof tile systems and metal shutters to roof tile debris. Three phases addressed the performance of tile roof systems and metal shutters impacted by roof tile debris. The first phase experimentally evaluated the tile fragment size and quantity generated by a tile striking a tile roof system. The second phase experimentally quantified the puncture vulnerability of common metal panel shutter systems as a function of tile fragment impact speed. The third phase provided context for interpretation of the experimental results through the use of a tile trajectory model. The results provide supporting evidence that while metal panel window shutters provide significant protection against a prevalent form of windborne debris, these systems are vulnerable to tile fragment puncture in design level tropical cyclones. These findings correlate with field observations made after Hurricane Charley (2004).

• Proceedings of the KSME Conference
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• 2000.11b
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• pp.692-697
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• 2000

Recently, Flat flame burners are hilighted in high-load burners. Our study contains flow field analysis of a flat flame burner. In this paper, We analyzed the direction and magnitude of the velocity in a round tile type burner with swirl angles, $10^{\circ},\;30^{\circ},\;50^{\circ}$. In the case of swirl angle $10^{\circ}$, because axial momentum is larger than radial momentum, Recirculation region was weakly developed. In the case of swirl angle $50^{\circ}$, Flow in front of the tile is distributed for radial direction. And Recirculation region is large. So, We expect that the radiation can be transmitted from tiles and the recirculation region may cause $NO_x$ reduction.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.48 no.2
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• pp.174-179
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• 2012

A new absorption material, cellulose sponge soaked in cement, was made for anechoic water tank and its acoustical properties were investigated by pulse methods. The sound absorption coefficient a (dB/cm) of the material was obtained in the frequency range of 40~120kHz from the echo reduction ER (dB) and insertion loss IL (dB) data. The result was averagely 1.8dB/cm higher than the sound absorption coefficient a (dB/cm) of cork-filled rubber which is one of the most effective absorption materials. The wedge (1.2~5.0cm long) type absorption tiles were made with this new material. The echo reduction ER (dB) of the absorption tile with 5.0cm wedge measured in water tank was higher than 20dB in the experimental frequency range.