Surface Texture Research Papers - Academia.edu (original) (raw)

The bidirectional texture function (BTF) is a 6D function that can describe textures arising from both spatially-variant surface reflectance and surface mesostructures. In this paper, we present an algorithm for synthesizing the BTF on an arbitrary surface from a sample BTF. A main challenge in surface BTF synthesis is the requirement of a consistent mesostructure on the surface, and to achieve that we must handle the large amount of data in a BTF sample. Our algorithm performs BTF synthesis based on surface textons, which extract essential information from the sample BTF to facilitate the synthesis. We also describe a general search strategy, called the -coherent search, for fast BTF synthesis using surface textons. A BTF synthesized using our algorithm not only looks similar to the BTF sample in all viewing/lighthing conditions but also exhibits a consistent mesostructure when viewing and lighting directions change. Moreover, the synthesized BTF fits the target surface naturally and seamlessly. We demonstrate the effectiveness of our algorithm with sample BTFs from various sources, including those measured from real-world textures.

- by
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- Information Systems, Texture Synthesis, Surface Texture

Rolling tires are excited from the contact with the rough road surface to vibrations, which cause rolling noise. A two scale approach is suggested, where at the macro-scale the vibration of the rolling tire structure is modeled by quite detailed finite element methods. The road surface is described using measured textures. A fine resolution finite element discretization of the tread rubber is performed in order to resolve the asperity contact. The material properties are described by a non-linear viscoelastic rubber model. The tread patch is enforced to approach the rough surface in a transient dynamics manner. From these investigations an enveloping surface profile is reconstructed to be used for the excitation.

- by U. Nackenhorst
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- Surface Texture

Wire electrical discharge machining (WEDM) technology has been widely used in conductive material machining. The WEDM process, which is a combination of electrodynamic, electromagnetic, thermaldynamic, and hydrodynamic actions, exhibits a complex and stochastic nature. Its performance, in terms of surface finish and machining productivity, is affected by many factors. This paper presents an attempt at optimization of the process parametric combinations by modeling the process using artificial neural networks (ANN) and characterizes the WEDMed surface through time series techniques. A feed-forward back-propagation neural network based on a central composite rotatable experimental design is developed to model the machining process. Optimal parametric combinations are selected for the process. The periodic component of the surface texture is identified, and an autoregressive AR(3) model is used to describe its stochastic component.

- by trevor spedding
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- Engineering, Technology, Process Optimization, Time Series

Texture segmentation is one of the early steps towards identifying surfaces and objects in an image. Textures considered here are de ned in terms of primitives called tokens. In this paper we h a ve developed a texture segmentation algorithm based on the Voronoi tessellation. The algorithm rst builds the Voronoi tessellation of the tokens that make up the textured image. It then computes a feature vector for each V oronoi polygon. These feature vectors are used in a probabilistic relaxation labeling on the tokens, to identify the interior and the border regions of the textures. The algorithm has successfully segmented binary images containing textures whose primitives have identical second-order statistics and a n umber of gray level texture images.

- by Anil Jain
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- Information Systems, Computer Science, Computer Vision, Statistics
- by Jiro Gyoba
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- Particle Size, White Noise, Surface Texture

The presidedress soil nitrate test (PSNT) and the presidedress tissue nitrogen test (PTNT) have been developed to assess residual soil nitrogen (N) sufficiency for corn (Zea mays L.) in the humid eastern U.S. We conducted field studies at 47 sites during 1990 and 1991 to evaluate the use of the PSNT and PTNT for corn in Coastal Plain, Piedmont, and Appalachian Ridge and Valley regions of Virginia. Seven rates of fertilizer N (0, 45, 90, 135, 180, 225, and 270 kg/ha) were applied at corn height of 0.40 to 0.50 m and replicated four times in a randomized complete block design. Whole corn plants and soil to a depth of 0.30 m were sampled when corn height was 0.15 to 0.30 m to estimate available soil N prior to the application of fertilizer N treatments. Corn grain yield response to fertilizer N was used to assess residual soil N availability. Nitrogen concentration of whole corn plants at 0.15 to 0.30 m height was not an accurate indicator of plant-available soil N. Corn yields were maximized without sidedress N at the 19 sites where soil NO 3 -N was at least 18 mg-kg -1 and at the 17 sites where soil (NO 3 +NH 4 )-N was at least 22 mg-kg -1 . The PSNT predicted corn N sufficiency regardless of soil physiographic region or surface texture; however, the critical values for NO 3 -N and (NO 3 +NH 4 )-N were 3 to 5 mg-kg -1 lower than those established in Pennsylvania and Maryland, where cooler soil temperatures may permit greater residence time of inorganic N.

- by Gregory Evanylo
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- Soil Science, Analytical Chemistry, Inorganic Chemistry, Agronomy

& We used fMRI to directly compare the neural substrates of three-dimensional (3-D) shape and motion processing for realistic textured objects rotating in depth. Subjects made judgments about several different attributes of these objects, including 3-D shape, the 3-D motion, and the scale of surface texture. For all of these tasks, we equated visual input, motor output, and task difficulty, and we controlled for differ-ences in spatial attention. Judgments about 3-D shape from motion involve both parietal and occipito-temporal regions. The processing of 3-D shape is associated with the analysis of 3-D motion in parietal regions and the analysis of surface texture in occipito-temporal regions, which is consistent with the different behavioral roles that are typically attributed to the dorsal and ventral processing streams. &

- by Hendrik Peuskens
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- Psychology, Cognitive Science, Magnetic Resonance Imaging, Attention

- by Xin Wang
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- Information Systems, Texture Synthesis, Surfaces, Surface Texture

Building surfaces with textures and microstructures provide important information for many military and civilian applications. The extraction of the information from aerial imagery is di cult due to problems such as perspective distortion, data de ciency, and corruption caused by shadows and occlusions. In this paper we present a Surface Texture and Microstructure Extraction (STME) system to deal with these problems, under the assumption that an initial site model is given and su cient camera and light source information is known. The infrastructure of the system is an Orthographic Facet Image Library (OFIL) that systematically collects building facet intensities from multiple aerial images into a datebase, eliminates the e ects of shadows and occlusions, and uses a Best Piece Representation (BPR) method to form a complete and consistent intensity represen-This work was funded by the RADIUS project under ARPA/Army TEC contract number DACA76-92-C-0041 and NSF grant CDA-8922572. 1 tation for each facet by combining intensities from di erent sources. A window extraction module focuses attention on wall facets, attempting to extract the 2-D window patterns attached to the walls using an Oriented Region Growing (ORG) technique. Combined with the UMass Ascender site modeling system and scene rendering algorithms, the system is typically useful for urban site model re nement and visualization.

- by Allen Hanson
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- Cognitive Science, Image Analysis, Microstructures, Aerial Imagery

... MU-WEI JIAN1, JUN-YU DONG1, JIA-HUA (JERRY) WU 2 ... 2 Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton Cambridge, United Kingdom E-MAIL: dongjunyu@ouc.edu.cn, jianmuwei@sohu.com, jerry.wu@sanger ... [5] Jian,... more

A numerical simulation has been carried out to investigate the buoyancy induced flow and heat transfer characteristics inside a wavy walled enclosure. The enclosure consists of two parallel wavy and two straight walls. The top and the bottom walls are wavy and kept isothermal. Two straight-vertical sidewalls are considered adiabatic. Governing equations are discretized using the control volume based Finite-Volume method with collocated variable arrangement. Simulation was carried out for a range of surface waviness ratios, =0.00-0.25; aspect ratios, A=0.25-0.5; and Rayleigh numbers Ra=100-107 for a fluid having Prandtl number equal to 1.0. Results are presented in the form of local and global Nusselt number distributions, streamlines, and isothermal lines for different values of surface waviness and aspect ratios. For a special case of =0 and A=1.0, the average Nusselt number distribution is compared with available reference. The results suggest that natural convection heat transfer is changed considerably when surface waviness changes and also depends on the aspect ratio of the domain. In addition to the heat transfer results, the heat transfer irreversibility (HTI) in terms of Bejan number (Be) was measured. For a set of selected values of the parameters (, A, and Ra), a contour of the Bejan number is presented at the end of this paper.

- by Prodip K Das
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- Engineering, Heat Transfer, Numerical Simulation, Mathematical Sciences
- by Kjeld Søballe
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- Biomedical Engineering, Hydroxyapatite, Medicine, Dogs

This paper deals with the definition of a new finishing process named fluidized bed machining (FBM). Material is removed from the workpiece by an abrasive solid emulsion and air flowing through all the equipment, scratching the surface to be finished. This process is able to produce an accurate surface finishing both on areas inaccessible to traditional methods and complex passages. 9 10 11

A gas sensor based on a b-alumina thick ®lm was recently developed on a laboratory scale. This sensor can be successfully used for selective detection of CO and NO x , resulting from an appropriate choice of the working temperature of the sensing element. This paper deals with the approach of the industrial transfer of the sensor prototype, mainly concerning the scale-up of the screen-printing procedure from a hand-operated apparatus to an industrial production machine. Many parameters were already investigated during the laboratory development, namely the ink composition in terms of organic/inorganic component ratio, the type and amount of the liquid dispersant and rheological agent, the composition and softening temperature of the binder, the balumina/binder weight ratio. During the industrial transfer, some other parameters must be considered, such as the particle size distribution of the ceramic components of the ink, the in¯uence of the mesh number of the screen fabric on the surface texture of the b-alumina ®lm, the viscosity performances of the ink as a function of the applied shear rate and ageing. A common commercial metallic paste was also used as reference for optimizing the characteristics of the b-alumina based ink.

- by Laura Montanaro
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- Materials Engineering, Electroceramics, Viscosity, Screen printing

City environments often lack textured areas, contain repetitive structures, strong lighting changes and therefore are very difficult for standard 3D modeling pipelines. We present a novel unified framework for creating 3D city models which overcomes these difficulties by exploiting image segmentation cues as well as presence of dominant scene orientations and piecewise planar structures. Given panoramic street view sequences, we first demonstrate how to robustly estimate camera poses without a need of bundle adjustment and propose a multi-view stereo method which operates directly on panoramas, while enforcing the piecewise planarity constraints in the sweeping stage. At last, we propose a new depth fusion method which exploits the constraints of urban environments and combines advantages of volumetric and viewpoint based fusion methods. Our technique avoids expensive voxelization of space, operates directly on 3D reconstructed points through effective kd-tree representation, and obtains a final surface by tessellation of backprojections of those points into the reference image.

- by Jana Kosecka
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- Geography, Computer Science, Earth, Image segmentation

The thermal contact conductance of coated, contacting aluminum 6061-T651 surfaces was studied experimentally. Four different coating materials, copper, silver, a phase mixture of copper-carbon, and a phase mixture of silver-carbon were evaluated using four different surface roughnesses for each coating material. All of the samples were tested at contact pressures of 125, 250, 375, and 500 kPa. The test results of thermal contact conductance are presented in terms of coating thickness, surface texture, and properties of the coating materials. Using the experimental data, dimensionless expressions were developed that relate the contact conductance of the phase mixture and pure coatings to the coating thickness, the surface roughness, the contact pressure, and the properties of the aluminum substrate. The effects of the surface roughness and of the phase mixture of the coatings on the thermal contact conductance were investigated. In addition, the load cycling effect on the thermal contact conductance was examined for bare aluminum 6061-T651 specimens.

- by John W Sheffield
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- Mechanical Engineering, Aerospace Engineering, Heat Transfer, Surface Roughness

The interactions between playa hydrology and playa-surface sediments are important factors that control the type and amount of dust emitted from playas as a result of wind erosion. The production of evaporite minerals during evaporative loss of near-surface ground water results in both the creation and maintenance of several centimeters or more of loose sediment on and near the surfaces of wet playas. Observations that characterize the texture, mineralogic composition and hardness of playa surfaces at Franklin Lake, Soda Lake and West Cronese Lake playas in the Mojave Desert (California), along with imaging of dust emission using automated digital photography, indicate that these kinds of surface sediment are highly susceptible to dust emission. The surfaces of wet playas are dynamic -surface texture and sediment availability to wind erosion change rapidly, primarily in response to fluctuations in water-table depth, rainfall and rates of evaporation. In contrast, dry playas are characterized by ground water at depth. Consequently, dry playas commonly have hard surfaces that produce little or no dust if undisturbed except for transient silt and clay deposited on surfaces by wind and water. Although not the dominant type of global dust, salt-rich dusts from wet playas may be important with respect to radiative properties of dust plumes, atmospheric chemistry, windborne nutrients and human health. Lake playas) in the Mojave Desert are dynamic and at times are vulnerable to wind erosion and dust emission when sufficiently soft and (or) loose. Surface sediments at dry playas, on the other hand, are typically stable and hard and thus generally do not emit large amounts of dust when undisturbed by human activities. The emphasis of this report is on the hydrologic and sedimentologic interactions that may sustain dust production from wet playas.

- by Richard Reynolds
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- Geology, Atmospheric Chemistry, Digital Photography, Public Domain

The development of user-friendly reference data sets (softgauges) and reference software algorithms for validating the software aspects of surface profile measuring instruments is described. A framework for the software measurement standards, and the form of the reference data (Type F1 softgauges) and reference software (Type F2) that were developed is discussed. This work was carried out as part of the UK

- by Richard Leach and +1
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- Materials Engineering, Mechanical Engineering, Wear, Tribology

Beef longissimus dorsi colour, marbling fat and surface texture are long established properties that are used in some countries by expert graders to classify beef carcasses, with subjective and inconsistent decision. As a computer vision system can deliver objective and consistent decisions rapidly and is capable of handling a greater variety of image features, attempts have been made to develop computerised predictions of eating quality based on these and other properties but have failed to adequately model the variation in eating quality. Therefore, in this study, examination of the ribeye at high magnification and consideration of a broad range of colour and marbling fat features was used to attempt to provide better information on beef eating quality. Wavelets were used to describe the image texture of the beef surface at high magnification rather than classical methods such as run lengths, difference histograms and cooccurrence matrices. Sensory panel and Instron analyses were performed on duplicate steaks to measure the quality of the beef. Using the classical statistical method of partial least squares regression (PLSR) it was possible to model a very high proportion of the variation in eating quality (r 2 = 0.88 for sensory overall acceptability and r 2 = 0.85 for 7-day WBS). Addition of non-linear texture terms to the models gave some improvements.

- by Patrick Jackman
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- Chemical Engineering, Computer Vision, Meat Science, Image Processing

This is a preprint of a paper intended forpublication in a journal orproceedings. Since changes may be made before publication, this preprint is made available with the understanding that it will not be cited or reproduced without the permission of the author. 1 I M,.STER , A_ OmTR_UTION OFTHiS DOOUMENT ISUNL_ITm _ DISCLAIMER This document was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor the University of California nor any of their employees, makes any warranty, express or implied, or ass umes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use _.. would not infringe privately owned rights. Reference herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring 1 by the United States Government or the University of California. The views and I opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or the University of California, and shall not be used for advertising or product endorsement purposes.

- by Nelson Max
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- Animation, Computational Geometry, Particle Image Velocimetry, Image segmentation

Most of superfinishing processes are based on the action of abrasive grains scratching the surface of a workpiece. These processes are known to improve the surface texture but they also modify the surface integrity, and thus the durability of engineering parts. In this paper, the residual stress field induced by the scratch of a single round abrasive grain is investigated by means of an implicit finite element analysis. First, it is shown that the residual stress profile is always modified over a depth of two or three times the contact radius, whatever the mechanical and physical properties. Second, key-parameters having a high influence on the tensile and compressive zone have been identified. They are the contact severity, the friction coefficient and the workpiece hardness. Third, it appears that the residual stress profile is not really affected by the presence of initial homogeneous residual stress field in the material. These results are then used to explain the experimental residual stress fields induced by a belt finishing process and a honing process on a AISI52100 hardened steel. Finally the possibility to design appropriate abrasive tools to improve both surface texture and surface integrity of manufactured parts is discussed.

- by Joel RECH and +2
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- Materials Engineering, Mechanical Engineering, Wear, Finite Element

Lightweight materials, structures and coupling mechanisms are very important for realizing advanced flight vehicles. Here, we obtained the geometric structures and morphologies of the elytra of beetles and ascertained its coupling zone by using the histological section technique and SEM. We set up a three-dimensional motion observing system to monitor the opening and closing behaviour of elytra in beetles and to determine the motion mechanism. We constructed a force measuring system to measure the coupling forces between elytra. The results show that elytra open and close by rotating about a single axle, where the coupling forces may be as high as 160 times its own bodyweight, the elytra coupling with the tenon and mortise mechanism, surface texture and opening angle between elytra heavily influence the coupling forces. These results may provide insights into the design mechanism and structure for future vehicles of flight.

- by yafeng Zhang and +1
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- Biological Sciences, Beetles, Mechanical Stress, Surface Properties

In this paper, the transient lubrication phenomena induced by isolated circular micro-cavities passing through an EHL point contact are analysed. A 52 100 steel ball was micro-machined using a femtosecond pulse laser, and is tested with an EHL tribometer. The experiments are simulated numerically with a 2D-multigrid solver. Under rolling-sliding conditions, the film thickness distribution is modified, and two opposite effects are observed. Deep micro-cavities induce an oil film decrease. On the contrary, a shallow micro-cavity locally generates a large increase in the film thickness. When the ball surface is the slowest, the propagation velocity of the local oil film reinforcement increases. r

Animals and plants have developed optimal geometric structures, smart topological materials and multi-functional surface textures with excellent tribological characteristics through the evolution of thousand millions of years and become models for tribological design. This paper puts forward the definition and fundament of biomimetic tribology, investigates the status of self-cleaning of liquid-solid interface, adhesion between animals' feet and solid surface, wear characteristics of biological surfaces and biomimetic design, as well as the friction and bionic design on liquid-solid interface. The further developments of the tribological biomimetics are discussed.

- by Zhendong Dai
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- Multidisciplinary, Research and Development, Surface Texture

The process conditions for a high-efficiency and low cost crystalline silicon solar cell were optimized. Novel approaches such as wafer cleaning and saw -damage removal using 0.5wt% of 2,4,6-trichloro-1,3,5-triazine, silicon surface texturing with optimized pyramid heights (∼5μm), and a third step of drive-in after phosphosilicate glass (PSG) removal followed by oxide removal were investigated. A simple method of chemical etching adopted for edge isolation was optimized with edge etching of 5–10μm, without any penetration of chemicals between the stacked wafers. The conversion efficiency, open-circuit voltage, short-circuit current, and fill factor of the cell fabricated with the optimized process were a maximum of 17.12%, 618.4mV, 5.32A, and 77% under AM1.5 conditions, respectively.

- by Lakshminarayan Nariangadu
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- Engineering, Process Optimization, Solar Cell, Physical sciences

Surface texturing, which fabricates micro dimples or micro channels on the surface of parts, is a growing technique for improving tribological characteristics of materials. Currently, electrical discharge texturing (EDT) technique, one surface texturing method suitable for mass production, is being used to texture aluminum sheets for the applications in automotive industry. It has been widely accepted in industry that EDT improves the forming behavior of aluminum sheets due to better friction behavior. However, how the textures on the surface of sheet metal change the friction behavior has not been investigated. In this paper, the influence of EDT on the friction behavior of aluminum automotive sheet at different contact pressures and sliding speeds is investigated based on both experimental studies and numerical simulations. To fully investigate the tribological behaviors, a flat-on-flat friction test device was built and a numerical code based on mixed lubrication theory was developed. It was found that EDT texturing can reduce the friction coefficient of contacting pair at high contact pressure, however, increase friction coefficient at low contact pressure. Numerical simulations confirmed this finding. Furthermore, the model provides valuable information for the prediction of friction behavior of EDT sheets and helps to optimize processing parameters for various forming processes using EDT aluminum sheets.

- by Jian Cao
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- Materials Engineering, Mechanical Engineering, Automotive Industry, Numerical Simulation

Individually visible scratches, also called isolated scratches, are very common in real world surfaces. Although their microgeometry is not visible, they are individually perceptible by the human eye, lying into a representation scale between BRDF and texture. In order to simulate this kind of scratches in synthetic images we need to know their position over the surface (texture scale), so we can determine where to use the specific scratch BRDF instead of the ordinary surface BRDF. Computing the BRDF of a scratch is difficult because it depends on the scratch's invisible microgeometry. In this paper, we propose a new physically based model to derive this microgeometry by simulating the formation process of scratches. We allow specifying intuitively the parameters involved in the process such as the scratching tool, the penetration forces, and the material properties of the object. From these parameters, we derive the microgeometries of the scratches by taking into account the real behaviour of the process. This behaviour has been determined by analysing existing models in the field of materials engineering and some "scratch tests" that we performed on metals. Our method has the advantages of easily simulating scratches with a wide range of microgeometries and taking into account the variability of their microgeometry along the scratch path. Another contribution is related to the location of the scratches over the surface. Instead of using an image of the paths as in previous work, we present a new representation based on curves defining the paths. This offers an independence on the image resolution or the distance from the observer and accurately provides the scratch direction in order to compute scratch BRDFs.

Rate laws have been determined for the aqueous oxidation of pyrite by ferric ion, dissolved oxygen and hydrogen peroxide at 30°C in dilute, acidic chloride solutions. Fresh, smooth pyrite grain surfaces were prepared by cleaning prior to experiments. Initial specific surface areas were measured by the multipoint BET technique. Surface textures before and after oxidation were examined by SEM. The initial rate method was used to derive rate laws. The specific initial rates of oxidation (moles pyrite cm -2 min -1) are given by the following rate laws (concentrations in molar units): rsp, Fe3+ = -10 -9.74M0.5Fe3+ M-0.5H+ ( pH 1-2) rsp, o2 = -10 -6.77M0.5O2 ( pH 2-4) rsp, h2o2 = -10 -1.43MH2O2 ( pH 2-4) An activation energy of 56.9 ± 7.5 kJ mole -1 was determined for the oxidation of pyrite by dissolved oxygen from 20-40°C. HPLC analyses indicated that only minor amounts of polythionates are detectable as products of oxidation by oxygen below pH 4; the major sulfur product is sulfate. Ferric ion and sulfate are the only detectable products of pyrite oxidation by hydrogen peroxide. Hydrogen peroxide is consumed by catalytic decomposition nearly as fast as it is by pyrite oxidation. SEM photomicrographs of cleaned pyrite surfaces indicate that prior to oxidation, substantial intergranular variations in surface texture exist. Reactive surface area is substantially different than total surface area. Oxidation is centered on reactive sites of high excess surface energy such as grain edges and corners, defects, solid and fluid inclusion pits, cleavages and fractures. These reactive sites are both inherited from mineral growth history and applied by grain preparation techniques. The geometry and variation of reactive sites suggests that the common assumption of a first-order, reproducible dependence of oxidation rates on surface area needs to be tested.

- by Michael A . McKibben
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- Geology, Geochemistry, Low Temperature, Surface Texture

A B S T R A C T Textured surfaces have been shown to provide enhanced tribological performance in a variety of contacts. Numerical analysis and optimisation methods are combined for application-oriented texture optimisation. However, an analytical approach is advantageous in providing more generic in-depth understanding of the nature of the relationships between texture parameters and objective functions, such as enhanced load carrying capacity and reduced friction. The paper outlines such an approach to obtain a set of global optimum design parameters for partially textured surfaces. The optimised results are expressed in dimensionless form, which enables their use for a variety of applications. The performance of optimised partially textured sliding surfaces is compared with the other conventional bearing geometries in their optimum state.

- by Ramin Rahmani
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- Tribology (Engineering), Lubrication, Surface Texturing, Surface Engineering

Introducing specific textures on a tribological surface can contribute to friction reduction in sliding contacts. In the present paper, a pulsed Nd:YAG laser emitting at 1064 nm, was used against 100Cr6 steel samples in order to produce well-defined surface micro-pores, which can act as lubricant reservoirs, micro-hydrodynamic bearings as well as traps for wear debris. Due to the high flexibility of the laser system, structural features such as shape, size, density and depth can be varied easily by changing the laser parameters. To optimize the parameters of the laser surface texturing process, an investigation was performed using different pulse numbers, various pulse energies and two different modes (single-and multi-mode). The microtextures were characterized with optical microscopy, scanning electron microscopy (SEM) and by topography techniques. The relationship between the laser processing parameters and qualitative and quantitative profile of the micro-pores was studied. Tribological testing of laser textured surfaces was performed in a low frequency-long displacement reciprocating sliding wear tester under boundary lubrication and results compared to un-textured case. Tribological comparison of textured, textured and lapped, and untextured surfaces shows only minimal influence of texturing for contact conditions investigated.

- by Bojan Podgornik
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- Mechanical Engineering, Scanning Electron Microscopy, Tribology, Low Frequency

. Thin films of cerium dioxide CeO were prepared on glass substrates by the spray pyrolysis process using an aqueous solution 2 Ž . of CeCl ,7H O or Ce NO . The structure, surface morphology chemical composition and optical properties of... more

- by M. Addou
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- Engineering, Technology, Raman Spectroscopy, Near Infrared

In this paper we present analysis, modeling and implementation of an efficient solar charge controller. Maximum power of a photovoltaic system is heavily dependent on temperature and insolation. We have employed the 'perturb and observe' algorithm for maximum power point tracking. A Fuzzy Rule Based System is designed for implementation of perturb and observe algorithm. This solar charge controller works with a PWM controlled DC-DC Inverter for battery charging. The system is implemented using an inexpensive PIC microcontroller. Results show improved performance as compared to conventional techniques in power efficiency and swift maximum power point tracking.

- by Taosif Iqbal
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- Dentistry, Renewable Energy, Energy Engineering, Light Scattering

Portable drug delivery system or portable syringe pump system is a small infusion pump used to gradually deliver drugs, at low doses and at a constant or controllable rate of drug to a patient who needs to take a drug dose regularly in... more

- by Mohammed S Jarjees
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- Dentistry, Renewable Energy, Energy Engineering, Light Scattering
- by Ayoub Shirvani
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- Engineering, Mechanical Engineering, Surface Texturing, Tribology

The study of textured surface performance is one of the highly researched topics in recent times. This is mainly due to the advantages that such surfaces can potentially provide in practice, in mitigating adverse tribological conditions, such as friction and wear. However, considering the complexities found in practice, a methodological analysis and evaluation procedure is essential in order to gain an understanding of the benefits from utilising such features in a given contact. The current study provides a combined analytical and experimental approach towards an enhanced understanding of the behaviour of textured surfaces relative to their untextured counterparts. The developed analytical models are invaluable in providing an insight into the relationship between the many parameters involved in defining even simple surface texture feature geometry and the expected outcomes in practice, when corroborated with experimental results. The current study reports on such an endeavour. With the studied texture configuration, the results have shown the possibility of reducing friction by as much as 25%.

- by Ramin Rahmani
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- Tribology (Engineering), Lubrication, Surface Texturing, Tribology

Petrographic, geochemical, and scanning electron microscope analyses of the sandstone and mudstone units of the Upper Miocene Injana Formation are presented. Furthermore, microprobe analysis for amphiboles, pyroxenes, garnet, and chromian spinels as common heavy mineral species present is done to support other results for better understanding of the provenance history of the Injana Formation. The sandstones of the Injana Formation consist of terrigenous carbonate lithic fragments as common type of sedimentary rock fragments in addition to chert, argillaceous, and rare sandstone fragments. They also include metamorphic and igneous lithic fragments, quartz, feldspars, and mica and generally, the sandstones are lithic arenites and immature. Scanning electron microscopic analysis for the heavy minerals shows that they have been affected by dissolution due to chemical etching and mechanical abrasion through several surface texture generated either in arid and semihumid environment or in diagenetic environment. Clay mineralogy of the mudstone units indicates the presence of illite, chlorite, kaolinite, palygorskite, and illite-smectite mixed layers. Bulk-rock and mineral phase geochemistry in addition to petrographic data suggest the derivation of the Injana Formation from a nearby sources with contribution from igneous, metamorphic, and sedimentary provenance mainly from the high lands in the northeastern parts of Iraq which comprise mainly the Zagros mountains and the older sedimentary formations. Jassim and Buday 2006 and many others), the majority of which focused on geological overviews of the formation and/or provided descriptions of its lithofacies, sedimentology, and depositional environments.

- by Ali Al-Juboury
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- Geology, Petrography, Clay mineralogy, Scanning Electron Microscope

This paper describes part of a large project on aggregate-cement interactions and interface bonding mechanisms in concrete. This part of the study investigates the influence of aggregate physical properties on the nature of aggregate-cement paste interfacial bonding with the aim of establishing the bonding mechanisms as controlled by aggregate physical properties. A newly developed experimental technique to characterise quantitatively the aggregate surface texture using a surface profilometer is also presented. Three commonly used concrete aggregate rocks (basalt, limestone, and quartzite) were investigated. Significant differences in the measured bond strength and modes of failure of rock-hardened cement paste composite specimens under uniaxial tension were observed between the different rock types. Based on the results presented, it is apparent that for a given cement paste, the interfacial bond strength cannot be predicted from aggregate surface roughness alone. © 1998

- by William Tasong and +1
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- Civil Engineering, Surface Roughness, Building, Bond Strength

Laser surface texturing (LST) by dimpling has been shown analytically and experimentally to enhance mixed, hydrodynamic, and hydrostatic lubrication of conformal sliding components. Improvements such as higher load-carrying capacity, higher wear resistance, and lower friction coefficients were observed in LST mechanical seals and thrust bearings. However, under non-conformal concentrated contact, the dimpled surface may have a different effect on the tribological behavior as a result of increased roughness, which may increase abrasive wear on the counterface. This paper discusses the effect of laser-textured surfaces on the tribological properties under a point ball-on-flat contact configuration. Tribological experiments were performed with dimpled flats in a pin-on-disk friction machine at speeds from 0.015 to 0.75 m/s using oils with different viscosity. Disks with dimples having different depths and densities were evaluated. Results showed that disks with higher dimple density produced more abrasive wear on the ball specimen. However, this higher wear rate led to faster generation of conformal contacts and a transition from the boundary to mixed lubrication regime, resulting in a rapid reduction in the friction coefficient with increased ball wear. The wear rate was higher in tests with lower viscosity oils, as expected. Results of the study may be beneficial for optimization of LST technology for industrial application in friction units.

- by George Fenske
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- Materials Engineering, Mechanical Engineering, Wear, Abrasive wear

An inherent weakness of masonry structures is low bond and bond strength. Although masonrv bond is a result of many interrelated factors (e.g. surface texture, surface absorption and mortar composition, etc.), surface absorption of masonry units has a significant effect on masonry bond. Following a critical review of the current measurements of the surface absorption of masonry units, the theoretical bases of sorptivity as a measurement of surface absorption are presented. The limitations of sorptivity measurement are discussed through a review of the application of the concept of sorptivity to different porous building materials. An experimental programme to examine the surface absorption of masonry units is described. Analysis of the results showed sorptivity to be a simple and reliable measurement of surface absorption for masonry units that could be used in building standards.

Surface measurement using 3D stylus instruments is a relatively new technique which offers numerous advantages over the more common profilometry methods. The information generated is, unlike profile measurements, less subjective and more statistically relevant providing additional insight regarding the surface structure. One application of surface measurement which has encountered problems when using the profilometry method is that of grinding wheel characterisation. The wheel surface texture (topography) and the conditions under which it is generated have a profound effect upon the grinding performance as characterised by the grinding forces, power consumption, temperature, and surface integrity of components. A detailed knowledge of the nature of the topography of the grinding wheel would provide further insight into the surface interaction of the grinding wheel as well as enabling improved control of the grinding process in general. Through the employment of novel 3D surface descriptors, this paper will investigate the topographic change which occurs on both the wheel and workpiece and attempt to relate this to force data and scanning electron microscopy. The results will demonstrate that this topographic characterisation technique correlates well with more accepted methods. #

This article examines materiality as a surface condition and as inscribed in the texture of photographic and filmic images. First, it discusses examples where surface textures become striking due to various, frequently combined factors, such as image transfer, enlargement, the exigencies of the machinery involved and the properties of the film stock. Here, image resolution is the main focus. Second, it deals with the case of camera-less photography and film, where apparent surfaces are caused by directly acting upon the photo paper or the film stock. The third part offers close-readings of three exemplary artworks to be apprehended as poignant and exciting examples of how a photograph’s or film’s materiality determines its meaning, how textuality and texturality match. These readings include Steven Pippin’s series of photographs Laundromat-Locomotion (1997), Alison Rossiter’s works with expired silver gelatine photo papers (2007-ongoing) and David Gatten’s film Secret History of the Dividing Line (2002). Finally, in my concluding remarks, I will briefly address the critical potential of textures that foreground their materiality.

- by Gabriele Jutz
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- Photography, Experimental Film, Materiality, Low Resolution

With the more precise demands of modern engineering products, the control of surface texture together with dimensional accuracy has become more important. This paper outlines the Taguchi optimization methodology, which is applied to optimize cutting parameters in end milling operation. The study was conducted in machining operation in hardened steel DIN GX40CRMOV5-1. The processing of the job was done by TiN coated carbide inserted end-mill tool under semi-finishing and finishing conditions of high-speed cutting. The milling parameters evaluated were cutting speed, feed rate and depth of cut. The experiments were conducted by using L-27 (313) orthogonal array as suggested by Taguchi. Signal-to- Noise (S/N) ratio and Pareto Analysis of Variance (ANOVA) are employed to analyze the effect of milling parameters on surface roughness. Main effects of process parameters on the quality characteristics have been analyzed. The results show that the optimum parameters of machining by CNC Milli...

- by Dalgobind Mahto
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- Orthogonal Array, Analysis of Variance, End milling, Process Parameters

Words and images behave in different ways. A picture of a miniskirt performs a different function than the naming of it. Barthes suggest that words make the image "intelligible: [that] it is not the object but the name that creates desire (Barthes 1990) … Orality implies community. Not only do we dress up; we talk about it' Abstract. The above suggests 'oral texture' as a method of communication or 'ideal and emotive novelisation', a utopian standard of image and self-transformation, set by the fashion, textiles and lifestyle perception makers. It is a system that has been used to sell or seduce magazines (imagery and supporting text) to the reader (wearer) since the late 19 th Century and blurred into the realms of retail sales and marketing, especially on-line. Society understands and indulges in this method of aesthetic communication, and for women, it is meant to represent 'women's mass culture'. [Naomi Wolf] This paper describes two fabric-touch experiments where the term 'oral texture' applies in the collection of adjectives and metaphors (fabric perceptions). The purpose of this study was to qualitatively record subjective responses to familiar fabrics, using a Repertory Grid (factor analysis) model , to preliminary establish subjective and objective responses to fabrics, and through analysis, the factors underlying fabric perception and discrimination between fabric 'types'.

- by wendy moody
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- Factor analysis, Pilot study, Repertory Grid, Indexation

Ultrasonic assisted magnetic abrasive finishing (UAMAF) integrates the use of ultrasonic vibrations and magnetic abrasive finishing (MAF) process to finish surfaces to nanometer order in a relatively short time. The present study emphasizes on the fabrication of UAMAF setup. Using this experimental setup, experimental studies have been carried out with respect to five important process parameters namely supply voltage, abrasive mesh number, rotation of magnet, abrasive weight percentage, and pulse on time (T on ) of ultrasonic vibrations selected based on literature available in the area of MAF process and ultrasonic generator controls. Percentage change in surface roughness (ΔRa) for AISI 52100 steel workpiece has been considered as response and unbonded SiC abrasives are used in the work. The experimental results showed that the UAMAF process has better finishing potential as compared to those obtainable by using MAF process for similar processing conditions. The surface roughness value obtained by UAMAF was as low as 22 nm within 80 s on hardened AISI 52100 steel workpiece using unbonded SiC abrasives. Scanning electron microscopy and atomic force microscopy studies were carried out to feel the surface texture produced and to identify finishing mechanism.

In this study, commercially pure titanium (cpTi) and a titanium alloy (Ti6Al4V) were subjected to waterjet (WJ) peening and abrasive waterjet (AWJ) peening surface treatments. The texture and in-plane biaxial residual stress of the treated surfaces were quantified using contact profilometry and X-ray diffraction, respectively. Regardless of the specific process conditions, the surface residual stresses resulting from WJ and AWJ peening of both materials were compressive. Residual stresses in the Ti6Al4V ranging −400 ≤ σ ≤ −30 MPa, whereas stresses in the cpTi treated with the same conditions ranging −200 ≤ σ ≤ −60 MPa. Residual stresses resulting from WJ peening increased with the WJ pressure whereas those resulting from AWJ peening decreased with an increase in both jet pressure and abrasive size. The surface roughness of the metals did not change appreciably with WJ treatment, but AWJ peening resulted in a significant increase in roughness. Therefore, AWJ peening may serve as a new method for introducing compressive residual stresses in engineering components that also require rough surfaces.

- by M. Ramulu
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- Materials Engineering, Mechanical Engineering, Titanium, Wear

Superalloys, such as Inconels and Incoloys, are extensively used where high strength is a requirement. However, where these materials are required to slide against one another, particularly with poor or no lubrication, high friction... more

- by Ulf Olofsson
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- Materials Engineering, Mechanical Engineering, Wear, Surface treatment

A new compression test unit was developed for the assessment of the surface properties of fibers. In order to measure the variation in the compression force during a test, a full bridge load cell was developed. It was seen that the signal coming from the strain gages was superimposed with noise. It was also found that the noise was from both electrical and mechanical sources. An extensive mathematical analysis of mechanical noise and the application of a mechanical noise reduction technique minimized the mechanical noise component. Analysis of electrical noise showed that the motion control card was interfacing with the Data Acquisition (DAQ) card via both the RS232 and the AC power line. It was necessary to separate the motion control unit and the DAQ unit in order to eliminate the electrical noise problem present in the system. After eliminating the noise from the unit, the calibration of the strain gages has been performed. The coefficient of correlation was found 1.00 with a cubic model.

- by William Oxenham
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- Signal Processing, Motion control, Cotton, Mathematical Analysis