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Modelling the hydrodynamic support of cylinder bore and piston rings with laser textured surfaces

Tomanik, Eduardo Augusto; Profito, Francisco José; Zachariadis, Demetrio Cornilios
Fonte: Netherlands Publicador: Netherlands
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
469.1508%
An one-dimensional computer model was used to simulated surface texture effects on engine cylinder bore, top and oil control rings. Steady state, reciprocating tests and engine conditions were considered. For the engine simulation, conditions close to the top reversal and at mid-stroke were simulated. Different micro-dimple geometries were considered, as well as full and partial texturing. As main conclusion, micro-dimples on the bore and rings were able to generate significant hydrodynamic support with potential to reduce both friction and wear. A special benefit was predicted when the micro-dimples were on the flat surface of the oil control rings.

Analysis of the functional quality of pavements from texture measurements

Freitas, Elisabete F.; Pereira, Paulo A. A.
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em //2007 ENG
Relevância na Pesquisa
487.70242%
The surface texture of a pavement, including uneveness, is largely determinant of drivers’safety and comfort. It is undoubtedly a major cause of road traffic accidents all over the world. Statistics show that one million killed and 50 million injured are reported every year by Competent Authorities. The effect of traffic noise has also become a critical public issue. On the road networking the surface characteristics of pavements also contributed to nearly 80-90% of roadway traffic noise. Not only engines or exhaust systems generate noise. The impact of tire-surface at speeds above 50 km/h also needs to be added to prime offenders. Functional requirements such as roadway safety, environmental quality, driving comfort and operating costs in the road network are assessed by indicators whose limits are continuously adjusted. The roadway texture is again a main intervenient. This paper aims at describing the texture indicators that can be used for the assessment of the texture of a pavement from a network point of view, based on profiles acquired at high speeds, including megatexture. First an overview of the concepts related to texture and the effects of texture, including unevenness, on safety, driving comfort, ride quality and environmental quality is given. Then...

Texture and noise features for road pavement identification and classification

Paulo, Joel; Freitas, Elisabete F.; Coelho, J. L. Bento
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em /06/2010 ENG
Relevância na Pesquisa
477.32414%
Road planners and road administrators frequently face the problem of insufficient knowledge of the correlation between the type of road surface and the resulting noise emission. The aim of this research is to establish the relationship between road surface characteristics, such as macrotexture, and tire/pavement noise emission, in order to identify and classify road surfaces by using statistical learning methods, which is a non-destructive approach. For this purpose, several road sections with different pavement types were selected and tested. The Close-Proximity (CPX) method was adopted, as it is commonly used to register the traffic noise in near field conditions. In its turn, macrotexture of each surface was provided by a high speed profilometer, which is one of the parameters required for the assessment of the performance and conformity of road pavements. The set of features extracted from the noise emission profile and from the surface texture was applied to a statistical classifier for evaluation. A correct identification of the road pavement leads to better data, thus enhancing the accuracy of road noise predictions. Results are presented and discussed.

Influence of surface texture by NH4Cl aqueous solution on the electrical and optical properties of al-doped zinc oxide films

Xiao-Yong,Gao; Qing-Geng,Lin; Yu-Fen,Liu; Jing-Xiao,Lu
Fonte: Sociedade Brasileira de Física Publicador: Sociedade Brasileira de Física
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2008 EN
Relevância na Pesquisa
683.4507%
Aluminum-doped zinc oxide (AZO) films were prepared on glass substrate by mid-frequency direct current reactive magnetron sputtering (MF-DC-MS). The influence of surface texture by NH4Cl aqueous solution on the surface morphology, electrical and optical properties of the AZO films was systematically investigated by scanning electron microscope, four-point probe and ultraviolet-visible-near infrared spectrophotometer, respectively. The results indicate that textured AZO film obtains a better texture surface for light trapping. The reflectivity for textured AZO film decreases drastically in visible light region and the electrical resistivity increases, which can be explained by the textured surface morphology of AZO film. The results above prove that NH4Cl aqueous solution is an appropriate candidate for AZO wet etching because of its easy control and relatively low cost.

CONJOINT MEASUREMENT OF GLOSS AND SURFACE TEXTURE

Ho, Yun-Xian; Landy, Michael S.; Maloney, Laurence T.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /02/2008 EN
Relevância na Pesquisa
486.0286%
Previous research on visual perception of surface material has focused primarily on smooth, matte surfaces, neglecting surfaces with pronounced three-dimensional (3D) texture or specularity. Furthermore, studies have typically focused on single material properties, with no consideration of possible interactions. In this study, we used a conjoint measurement design to determine how observers represent perceived 3D texture (“bumpiness”) and specularity (“glossiness”) and modeled how each of these two surface material properties affects perception of the other. Observers made judgments of “bumpiness” and “glossiness” of surfaces that varied in both surface texture and specularity. We found that a simple additive model captures visual perception of texture and specularity and their interactions. We quantify how changes in each surface material property affect judgments of the other. Conjoint measurement is potentially a powerful tool for analyzing surface material perception in realistic environments.

Capturing the Surface Texture and Shape of Pollen: A Comparison of Microscopy Techniques

Sivaguru, Mayandi; Mander, Luke; Fried, Glenn; Punyasena, Surangi W.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 12/06/2012 EN
Relevância na Pesquisa
488.3248%
Research on the comparative morphology of pollen grains depends crucially on the application of appropriate microscopy techniques. Information on the performance of microscopy techniques can be used to inform that choice. We compared the ability of several microscopy techniques to provide information on the shape and surface texture of three pollen types with differing morphologies. These techniques are: widefield, apotome, confocal and two-photon microscopy (reflected light techniques), and brightfield and differential interference contrast microscopy (DIC) (transmitted light techniques). We also provide a first view of pollen using super-resolution microscopy. The three pollen types used to contrast the performance of each technique are: Croton hirtus (Euphorbiaceae), Mabea occidentalis (Euphorbiaceae) and Agropyron repens (Poaceae). No single microscopy technique provided an adequate picture of both the shape and surface texture of any of the three pollen types investigated here. The wavelength of incident light, photon-collection ability of the optical technique, signal-to-noise ratio, and the thickness and light absorption characteristics of the exine profoundly affect the recovery of morphological information by a given optical microscopy technique. Reflected light techniques...

Generalization of Cue Recruitment to Non-moving Stimuli: Location and Surface-texture Contingent Biases for 3-D Shape Perception

Jain, Anshul; Backus, Benjamin T.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
485.56938%
Long-lasting perceptual biases can be acquired through training in cue recruitment experiments (e.g. Backus, 2011, Haijiang, Saunders, Stone & Backus, 2006). Stimuli in previous studies contained motion, so the learning could be explained as an idiosyncrasy in some specific neuronal population such as the middle temporal (MT) area (Harrison & Backus, 2010a). The current study addresses the generality of cue recruitment by testing whether motion is necessary for learning a cue-contingent perceptual bias. We tested whether location and a novel cue, surface texture, would be recruited as cues to disambiguate perceptually bistable stationary 3-D shapes. In Experiment 1, stereo and luminance cues were used to disambiguate shape according to location in the visual field, and observers’ (N=10) percepts on ambiguous test trials became biased in favor of the contingency during training. This bias lasted into the following day. This result together with previous studies that used moving stimuli suggests that location-contingent biases are easily learned by the visual system. In Experiment 2, location was fixed, and instead the new cue to be recruited was a surface texture. Learning did not occur when stimuli were para-foveal, texture was task-irrelevant...

The Influence of Tool Path Strategies on Cutting Force and Surface Texture during Ball End Milling of Low Curvature Convex Surfaces

Shajari, Shaghayegh; Sadeghi, Mohammad Hossein; Hassanpour, Hamed
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
Publicado em 20/02/2014 EN
Relevância na Pesquisa
482.47734%
Advancement in machining technology of curved surfaces for various engineering applications is increasing. Various methodologies and computer tools have been developed by the manufacturers to improve efficiency of freeform surface machining. Selection of the right sets of cutter path strategies and appropriate cutting conditions is extremely important in ensuring high productivity rate, meeting the better quality level, and lower cutting forces. In this paper, cutting force as a new decision criterion for the best selection of tool paths on convex surfaces is presented. Therefore, this work aims at studying and analyzing different finishing strategies to assess their influence on surface texture, cutting forces, and machining time. Design and analysis of experiments are performed by means of Taguchi technique and analysis of variance. In addition, the significant parameters affecting the cutting force in each strategy are introduced. Machining strategies employed include raster, 3D-offset, radial, and spiral. The cutting parameters were feed rate, cutting speed, and step over. The experiments were carried out on low curvature convex surfaces of stainless steel 1.4903. The conclusion is that radial strategy provokes the best surface texture and the lowest cutting forces and spiral strategy signifies the worst surface texture and the highest cutting forces.

Bio-inspired design of ice-retardant devices based on benthic marine invertebrates: the effect of surface texture

Mehrabani, Homayun; Ray, Neil; Tse, Kyle; Evangelista, Dennis
Fonte: PeerJ Inc. Publicador: PeerJ Inc.
Tipo: Artigo de Revista Científica
Publicado em 23/09/2014 EN
Relevância na Pesquisa
484.18668%
Growth of ice on surfaces poses a challenge for both organisms and for devices that come into contact with liquids below the freezing point. Resistance of some organisms to ice formation and growth, either in subtidal environments (e.g., Antarctic anchor ice), or in environments with moisture and cold air (e.g., plants, intertidal) begs examination of how this is accomplished. Several factors may be important in promoting or mitigating ice formation. As a start, here we examine the effect of surface texture alone. We tested four candidate surfaces, inspired by hard-shelled marine invertebrates and constructed using a three-dimensional printing process. We examined sub-polar marine organisms to develop sample textures and screened them for ice formation and accretion in submerged conditions using previous methods for comparison to data for Antarctic organisms. The sub-polar organisms tested were all found to form ice readily. We also screened artificial 3-D printed samples using the same previous methods, and developed a new test to examine ice formation from surface droplets as might be encountered in environments with moist, cold air. Despite limitations inherent to our techniques, it appears surface texture plays only a small role in delaying the onset of ice formation: a stripe feature (corresponding to patterning found on valves of blue mussels...

Desgaste corrosivo-cavitativo-erosivo de um aço-carbono em meio aquoso com frações de sal (NaCl), CO2 e particulados sólidos (SiO2); Corrosive-cavitative-crosive wear of a carbon steel in aqueous medium with salt (NaCl), CO2 and solid particulates (SiO2) fractions

Silva, Fernando Nunes da
Fonte: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Engenharia Mecânica; Tecnologia de Materiais; Projetos Mecânicos; Termociências Publicador: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Engenharia Mecânica; Tecnologia de Materiais; Projetos Mecânicos; Termociências
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
471.14027%
A batch of eighty-four coupons of low carbon steel were investigated at laboratory conditions under a corrosive, cavitative-corrosive (CO2) and corrosive-erosive (SiO2 + CO2) in an aqueous salt solution and two levels of temperature. The following measurements were made on Vickers (HV0,05, HV0,10, HV0,20) Microhardness tests at three levels of subsurface layer. A turbulent flow collided on the cylindrical sample, with and without mechanical stirring and gas bubbling, with and without fluid contamination by solid particles of SiO2, at two temperatures. Surface Roughness and Waviness, under two conditions "as received, after machining" and "after worn out", as well as gravimetric and electrochemical parameter were measured on the two opposite generatrices of each cylindrical sample, on the flow upstream (0°) and downstream (180°) by Profilometry, Mass Variation and Linear Polarization Resistance (LPR). The results of the Microhardness and Surface Texture of all coupons were subjected to statistical comparison, using the software Statgraphics® Centurion XVI, 95% statistical certainty, and significant differences were observed in some arrays of measurements. The corrosive wear rate measured by LPR and mass variation shown to be sensitive to the presence of bubbles and hydrodynamic fluctuations inside the cell...

The effect of clinical polishing protocols on ceramic surface texture and wear rate of opposing enamel: a laboratory study.

Zaninovich, Michael
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2014
Relevância na Pesquisa
482.1185%
There has been a significant increase in the delivery of all ceramic restorations especially with the global explosion of CAD CAM technology. Frequently, the ceramic restorations require refinements to the surfaces with abrasives prior to or after cementation. If adjustments are made to a glazed or non-glazed surface after cementation, only mechanical polishing is an option to restore the surface texture. Surface roughness of ceramic restorations influences the aesthetics, functional and biological parameters of the restoration [1, 2]. A relatively rough surface can negatively influence the strength [3, 4] and longevity of a restoration [5, 6], increase friction [7] and rate of wear of the restoration [8] and opposing tooth structure [9], promote gingival inflammation [10], adverse soft tissue reactions [11], and the accumulation of stains and plaque on the surface [12-14]. Recent low fusing ceramics have properties which improve the surface characteristics and allows a relatively smoother surface to be achieved either by glazing or polishing [15, 16]. The aim of this study is to increase the understanding of the surface characteristics produced from either glazing or polishing and what impact the surface texture produced from such finishing methods has on the wear rate of opposing enamel. Clinically this will assist with decision making regarding the most effective method to achieve an optimal ceramic surface finish.; Thesis (D.Clin.Dent.) -- University of Adelaide...

The Scale Effect of Roughness on Hydrodynamic Contact Friction

DEMIRCI, Ibrahim; MEZGHANI, Sabeur; YOUSFI, Mohammed; ZAHOUANI, Hassan; EL MANSORI, Mohamed
Fonte: STLE Publicador: STLE
EN
Relevância na Pesquisa
481.4202%
Multistage abrasive finishing processes (grinding, polishing, honing, etc.) are commonly used to produce the geometrical properties of a surface to meet its technical functionalities in the operating characteristics of contacting parts in friction, relating to their durability and reliability (running-in performance, wear resistance, load-carrying capacity, etc.). Coarse abrasive grits followed progressively finer ones are used, which leads to a multiscale stratified surface texture. In this article, a numerical model of elastohydrodynamic (EHD) contact coupled to a multiscale surface texture model was developed that allows tracking the scale effect of surface features and their interactions on friction performance and lubricant flow under hydrodynamic lubrication conditions. Because the simulation model has as an input the surface topography and to overcome the variability in surface finish formation, textured surfaces at different stages of the finishing process were simulated (virtual texturing method). Surface topography can be decomposed into two principal components: superficial roughness and valleys. Superficial roughness was modeled using a fractal model and a scaling factor was introduced to model valley patterns. The results show the relationship between friction and surface scales.

The effect of groove texture patterns on piston-ring pack friction

MEZGHANI, Sabeur; DEMIRCI, Ibrahim; ZAHOUANI, Hassan; EL MANSORI, Mohamed
Fonte: Elsevier Publicador: Elsevier
EN
Relevância na Pesquisa
584.18668%
A cylinder liner possesses fairly intricate surface requirements due to its complicated functions. It needs to provide adequate surface roughness to resist wear as well as to store and retain lubricants during high temperatures. The liner surface texture is anisotropic, produced by the honing process, with resultant deep visible scratches left on it [1]. The prominence of the honing grooves observed suggests that surface texture significantly affects ring-pack performance, although this effect is not clearly understood. In this paper, a numerical model was developed to investigate the effects of groove characteristics on the lubrication condition and friction at the interface between the piston ring and cylinder liner. This model aims to solve the average Reynolds equation, which depends on the real surface topographies of the cylinder liner, and describes the influence of surface irregularities on the lubricant flow under hydrodynamic lubrication conditions, considering lubricant film rupture and cavitations. Numerical results help to determine the optimum lateral groove characteristics to reduce friction and then noxious emissions.

Avaliação do ensaio de angularidade do agregado fino (FAA) da especificação Superpave; LABORATORY EVALUATION OF THE FINE AGGREGATE ANGULARITY (FAA) TEST

Gouveia, Lilian Taís de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 28/02/2002 PT
Relevância na Pesquisa
481.1296%
O desempenho dos pavimentos de concreto asfáltico depende das propriedades e proporções relativas dos seus principais componentes, ou seja, dos agregados minerais, do cimento asfáltico e do volume de vazios. O desempenho das misturas asfálticas de graduação densa é predominantemente influenciado pelas características de forma, angularidade e textura superficial dos agregados finos, que condicionam a estabilidade das misturas. O ensaio de Angularidade do Agregado Fino (FAA), adotado pelo Superpave para avaliar e quantificar a forma, a angularidade e a textura superficial das partículas, tem levantado muitas dúvidas quanto à sua adequabilidade. O objetivo deste trabalho é verificar se o ensaio FAA é capaz de classificar os agregados finos, identificando materiais com melhores condições para utilização em misturas asfálticas. Para tanto, são realizados, além de ensaios de angularidade do agregado fino, análise visual da forma, angularidade e textura superficial, ensaios de cisalhamento direto em amostras de agregado fino e ensaios Marshall em amostras de misturas asfálticas produzidas com diferentes agregados finos. Os resultados obtidos nas análises visuais indicam que o ensaio FAA não é capaz de separar os efeitos de angularidade e de forma das partículas. Os resultados dos ensaios de cisalhamento direto demonstram que um agregado fino com maior FAA não apresenta...

Dietary Abrasiveness Is Associated with Variability of Microwear and Dental Surface Texture in Rabbits

Schulz, Ellen; Piotrowski, Vanessa; Clauss, Marcus; Mau, Marcus; Merceron, Gildas; Kaiser, Thomas M.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 06/02/2013 EN
Relevância na Pesquisa
483.70754%
Dental microwear and 3D surface texture analyses are useful in reconstructing herbivore diets, with scratches usually interpreted as indicators of grass dominated diets and pits as indicators of browse. We conducted feeding experiments with four groups of rabbits (Oryctolagus cuniculus) each fed a different uniform, pelleted diet (lucerne, lucerne & oats, grass & oats, grass). The lowest silica content was measured in the lucerne and the highest in the grass diet. After 25 weeks of exposure to the diets, dental castings were made of the rabbit's lower molars. Occlusal surfaces were then investigated using dental microwear and 3D areal surface texture analysis. In terms of traditional microwear, we found our hypothesis supported, as the grass group showed a high proportion of (long) “scratches” and the lucerne group a high proportion of “pits”. Regardless of the uniform diets, variability of microwear and surface textures was higher when silica content was low. A high variability in microwear and texture analysis thus need not represent dietary diversity, but can also be related to a uniform, low-abrasion diet. The uniformity or variability of microwear/texture analysis results thus might represent varying degrees of abrasion and attrition rather than a variety of diet items per se.

Use of biomimetic hexagonal surface texture in friction against lubricated skin

Tsipenyuk, Alexey; Varenberg, Michael
Fonte: The Royal Society Publicador: The Royal Society
Tipo: Artigo de Revista Científica
Publicado em 06/05/2014 EN
Relevância na Pesquisa
477.32414%
Smooth contact pads that evolved in insects, amphibians and mammals to enhance the attachment abilities of the animals' feet are often dressed with surface micropatterns of different shapes that act in the presence of a fluid secretion. One of the most striking surface patterns observed in contact pads of these animals is based on a hexagonal texture, which is recognized as a friction-oriented feature capable of suppressing both stick–slip and hydroplaning while enabling friction tuning. Here, we compare this design of natural friction surfaces to textures developed for working in similar conditions in disposable safety razors. When slid against lubricated human skin, the hexagonal surface texture is capable of generating about twice the friction of its technical competitors, which is related to it being much more effective at channelling of the lubricant fluid out of the contact zone. The draining channel shape and contact area fraction are found to be the most important geometrical parameters governing the fluid drainage rate.

Bio-inspired design of ice-retardant devices based on benthic marine invertebrates: the effect of surface texture

Mehrabani, Homayun; Ray, Neil; Tse, Kyle; Evangelista, Dennis
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
483.4507%
Growth of ice on surfaces poses a challenge for both organisms and for devices that come into contact with liquids below the freezing point. Resistance of some organisms to ice formation and growth, either in subtidal environments (e.g. Antarctic anchor ice), or in environments with moisture and cold air (e.g. plants, intertidal) begs examination of how this is accomplished. Several factors may be important in promoting or mitigating ice formation. As a start, here we examine the effect of surface texture alone. We tested four candidate surfaces, inspired by hard-shelled marine invertebrates and constructed using a three-dimensional printing process. We screened biological and artifical samples for ice formation and accretion in submerged conditions using previous methods, and developed a new test to examine ice formation from surface droplets as might be encountered in environments with moist, cold air. It appears surface texture plays only a small role in delaying the onset of ice formation: a stripe feature (corresponding to patterning found on valves of blue mussels, Crassostrea gigas, or on the spines of the Antarctic sea urchin, Sterechinus neumayeri) slowed ice formation an average of 25% compared to a grid feature (corresponding to patterning found on sub-polar butterclams...

Quantitative morphologic analysis of boulder shape and surface texture to infer environmental history: A case study of rock breakdown at the Ephrata Fan, Channeled Scabland, Washington

Ehlmann, Bethany L.; Viles, Heather A.; Bourke, Mary C.
Fonte: American Geophysical Union Publicador: American Geophysical Union
Tipo: Article; PeerReviewed Formato: application/pdf
Publicado em 06/05/2008
Relevância na Pesquisa
473.46133%
Boulder morphology reflects both lithology and climate and is dictated by the combined effects of erosion, transport, and weathering. At present, morphologic information at the boulder scale is underutilized as a recorder of environmental processes, partly because of the lack of a systematic quantitative parameter set for reporting and comparing data sets. We develop such a parameter set, incorporating a range of measures of boulder form and surface texture. We use standard shape metrics measured in the field and fractal and morphometric classification methods borrowed from landscape analysis and applied to laser-scanned molds. The parameter set was pilot tested on three populations of basalt boulders with distinct breakdown histories in the Channeled Scabland, Washington: (1) basalt outcrop talus; (2) flood-transported boulders recently excavated from a quarry; and (3) flood-transported boulders, extensively weathered in situ on the Ephrata Fan surface. Size and shape data were found to distinguish between flood-transported and untransported boulders. Size and edge angles (∼120°) of flood-transported boulders suggest removal by preferential fracturing along preexisting columnar joints, and curvature data indicate rounding relative to outcrop boulders. Surface textural data show that boulders which have been exposed at the surface are significantly rougher than those buried by fan sediments. Past signatures diagnostic of flood transport still persist on surface boulders...

Technique for analysis of surface topography of photographic prints by spatial analysis of first surface reflectance

Arney, Jonathan; Michel, James; Pollmeier, Klaus
Fonte: The Society for Imaging Science and Technology (IS&T) Publicador: The Society for Imaging Science and Technology (IS&T)
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
487.34055%
Visual examination of a large number of historic photographs indicates a significant variation in the surface texture in the paper on which the prints were made. This suggests that a thorough survey and quantification of surface texture would provide a useful tool for verifying the provenance of historic prints. The objective of the current project was to develop a digital imaging instrument and analytical protocol for capturing and evaluating the surface texture of papers beneath the gelatin/silver image of historic prints. The technique developed to accomplish this objective involves unique characteristics of the gelatin/silver print but is based on well known optical characteristics of materials. In particular, the behavior of first surface reflected light from the gelatin is distinguishable from the diffusely reflected light from the underlying paper, and analysis based on these properties has lead to a useful analytical tool for extracting an image of the paper surface texture and digitally eliminating the diffuse photographic image.; This article may be accessed on the publisher's website (additional fees may apply) at: http://www.imaging.org/store/epub.cfm?abstrid=8151

Laser-based assessment of road aggregate particle shape and texture properties with the aim of deriving comparative models

Breytenbach,J; Anochie-Boateng,J K; Paige-Green,P; van Rooy,J L
Fonte: Journal of the South African Institution of Civil Engineering Publicador: Journal of the South African Institution of Civil Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2013 EN
Relevância na Pesquisa
472.31312%
Research was undertaken using an innovative three-dimensional (3D) laser scanning tool to study the shape and texture characteristics of road aggregate particles. Aggregate materials used for road construction, including G1 crushed rocks of different geological origins, recycled aggregate and alluvial gravel (not used as aggregate) were used for this study. Representative samples were scanned using the laser system to collect 3D aggregate data for analyses and, subsequently, develop comparative models. The objective was to arrange the aggregate particles in a sequence based on their surface texture. Two models were proposed and key aspects evaluated against each other. Ultimately, one model was selected that may be improved and used for further research. The study found that, while it is possible to use the 3D aggregate scan data to produce comparative models, distinguishing between particle shape and texture proved a daunting task. It was also concluded that particle elongation must be considered as a major influencing factor.