Roughness Research Papers - Academia.edu (original) (raw)

- by
- •
- Nanowires, Resistivity, Conductivity, Chip

Wood coatings are widely used for aesthetic and protective reasons. Assessment of coating performance during service life is crucial in order to establish a knowledge database for product optimization. A vast amount of techniques is available for analysis of a coating's behavior of which micro-imaging is an important tool. In addition to standard microscopy techniques, high-resolution X-ray tomography is presented as a modality offering non-destructive visualization of a coating and the substrate applied on. Combined with analysis of the 3D volumetric data, surface roughness, structure and thickness of the coating layer, penetration depth and related mechanical anchoring can be studied in relation with the underlying substrate. To provide a clear illustration of the possibilities and limitations of this technique, both an opaque solvent-borne and an opaque water-borne coating applied on two different wood types were scanned and analyzed. Clearly, three-dimensional X-ray imaging at high resolution produces valuable information merely by visualization. Moreover by proper analysis quantitative data is obtained taking into account the limitations of Xray computed tomography and of automated image processing.

- by Joris C R Van Acker
- •
- Materials Engineering, Materials Science, Image Processing, X-ray imaging

Wind tunnel testing has been carried out on nine-knitted single jersey fabrics (100% polyester) using cylinder and leg models to determine its aerodynamic behaviour over a range of speeds (20–80 km/h) representative of sports activities. Strong correlation between fabric manufacturing (cover factor) and fabric roughness and aerodynamic parameters has been established. Similar aerodynamic behaviour of fabrics was observed when tested on

- by firoz alam
- •
- Mechanical Engineering, Textiles, Aerodynamics, Wind Tunnel test

Measurement of seafloor microtopography is rapidly approaching the status as a standardized element of geoacoustic characterization of the sea floor. With the advent of underwater stereo cameras and, recently, multiple-megapixel digital cameras adapted for underwater use, more investigators are measuring seafloor roughness at high resolution for applications to high-frequency acoustic modeling. An assessment of the methodologies used to characterize seafloor roughness, the parameterizations of the characterization of seafloor roughness, and the predictability of seafloor roughness seems appropriate at this time. Use of the roughness power spectrum to characterize seafloor roughness has a wide applicability for acoustic modelers. Currently, the slope and intercept of the regression line through the roughness power spectrum are used to parameterize seafloor roughness for acoustic modeling. Recent availability of digital roughness height datasets allows computation of two-dimensional roughness power spectra at sub-cm resolution. Ideally, these 2-D spectra would make the estimation of 2-D roughness parameters from 1-D roughness parameters unnecessary. Although much seafloor microtopography has been characterized concomitantly with sediment grain size, empirical prediction of roughness from grain size remains problematic. The inherent problem in relating seafloor roughness parameters to grain size is that the sediment-water interface is dynamic. Although seafloor microtopography may be thought to evolve predictably through cycles driven by hydrodynamic and biological processes, the rates of these processes and the resultant bedforms are highly variable. Another aspect of seafloor roughness that needs to be addressed is the character of its power spectrum over several orders of magnitude of spatial dimensions.

- by David Kukulka
- •
- Mechanical Engineering, Environmental Science, Heat Transfer, Heat Exchanger

An experimental study was performed to evaluate the bond strength between two concrete layers, using different techniques for increasing the roughness of the substrate surface and a commercial epoxy-based bonding agent. A total of 40 slant shear half specimens and 40 pull-off half specimens first had the substrate surface prepared by wire-brushing, sand-blasting, chipping with a light jackhammer, or were left as-cast against steel formwork. Three months later, the bonding agent was applied and the new concrete was added. Pull-off tests and slant shear tests were performed to evaluate the bond strength in tension and in shear. Analysis of the results indicates that the application of an epoxy-based bonding agent does not improve the bond strength since the adopted method for surface preparation adequately increases its roughness.

- by Vitor Silva
- •
- Civil Engineering, Materials Science, Building, Experimental Study

The purpose of this research is to investigate multipath arrival structures that are present in received passive sonar data and exploit this for enhanced passive sonar detection and tracking capability. OBJECTIVES Inherent in passive sonar systems are several challenges that any effective system implementation must address. One of these challenges is how to best treat multipath arrivals. In some cases these can be a hindrance while in this research they are exploited. In certain environments, multipath arrivals retain significant coherence with respect to each other. This fact has been noted and exploited in recent decades with the development of the class of techniques known as matched field processing (MFP). While there has been a significant amount of academic focus on developing this approach in the context of the more established array processing methodologies, its practical adoption has been hampered due to the need for accurate environmental models. Despite this shortfall, the conceptual basis of using multipath arrivals to enhance target localization still holds promise. In this project, the emphasis is on analytically and experimentally determining techniques to measure and utilize multipath. Recent studies into localization of marine mammals have shown that with only rough environmental models, 3-D localization is possible using a single hydrophone [Tiemann, 2006]. The principle of using multipath for range-depth localization is not new, however until recently the computational complexity of applying this to azimuth-dependent bathymetry has been prohibitive. Whale clicks are impulsive, so multipath structure is evident in raw time-domain data. However, this is not true of vessel noise, so this localization concept is extended to pulse compressed time-series data [See publication #1]. Recent advances in robotics, low power embedded computing, and sensor technologies (to name a few) have led to the advent of autonomous underwater vehicles (AUVs). Determining the best ways of designing passive sonar systems for these mobile platforms is an active area of research. In the GLASS'12 experiment performed by CMRE (with Portland State University collaborating), a hybrid (glider/propeller) AUV was outfitted with a compact nose-mounted hydrophone array consisting of tetrahedral and vertical line sub arrays. The small aperture, rigid frame, and high sample rate are

- by Martin Siderius
- •
- Signal Processing, Underwater Acoustics, Noise, Processing

Introduction-L'objectif de cette étude est de quantifier l'influence de la rugosité et du fartage des semelles de ski dans la performance en situation de patinage en ski de fond. Synthèse des faits-Les facteurs expérimentaux sont le skieur, la topographie et le fart de glisse ; chacun se décline en trois modalités. Neuf essais-avec variation de tous les facteurs à chaque essai-sont définis à l'aide de la technique des matrices d'expériences structurées en carré latin. Chaque combinaison des trois facteurs est testée sur un parcours plat de 200 m avec enregistrement du temps sur 30 m. Les neuf essais sont répétés trois fois dans une séance. Vingt et une séances de tests sont organisées au cours d'une saison hivernale. Les résultats montrent une influence prédominante du facteur skieur dans la performance en patinage par rapport aux influences de la topographie et du fart. Conclusion-En situation de patinage, le niveau d'expertise du skieur est prépondérant ; mais à niveau d'expertise égale, la différence sur la performance entre un bon et un mauvais choix de topographie et de fartage de la semelle de ski est comprise entre 3 et 10 %.  2002 Éditions scientifiques et médicales Elsevier SAS fart / méthodologie / performance / ski de fond

- by Pierre Lanteri
- •
- Mechanical Engineering, Methodology, Performance, Experimental Design

In this report we show that the amplitude of specularly diffracted light from a plane rough surface as a function of incident angle cosine is Fourier transform of the height distribution on the surface. Therefore, an even height distribution function, which is the case for many rough surfaces, can be obtained by measuring the specularly diffracted light intensities. Also, it is observed that for polychromatic illumination the spectrum of the specularly diffracted light is modified and the modification depends on roughness, incident angle, and wavelength. It is also shown that, for a fixed incident angle, the height distribution on the rough plane is Fourier transform of the spectral modifying function. Experimental studies on some surfaces of different roughnesses, prepared by grinding sheet-glasses by powders of different grain sizes, show that the corresponding height distributions are Gaussian and the rms heights obtained by the two approaches are quite consistent.

- by Masoomeh M Dashtdar
- •
- Light Scattering, Glass, Coherence, Grain size

The recourse to operation research solutions has strongly increased the performances of scheduling task in the High-Level Synthesis (called hardware compilation). Scheduling a whole program is not possible as too many constraints and objectives interact. We decompose high-level scheduling in three steps. Step 1: Coarse-grain scheduling tries to exploit parallelism and locality of the whole program (in particular in loops, possibly imperfectly nested) with a rough view of the target architecture. This produces a sequence of logical steps, each of which contains a pool of macro-tasks. Step 2: Micro-scheduling maps and schedules each macro-task independently taking into account all peculiarities of the target architecture. This produces a reservation table for each macro-task. Step 3: Fine-grain scheduling refines each logical step by scheduling all its macro-tasks. This paper focuses on the third step. As tasks are modeled as reservation tables, we can express resource constraints using dis-equations (i.e., negations of equations). As most scheduling problems, scheduling tasks with reservation tables to minimize the total duration is NP-complete. Our goal here is to design different strategies and to evaluate them, on practical examples, to see if it is possible to find optimal solution in reasonable time. The first algorithm is based on integer linear programming techniques for scheduling, which we adapt to our specific problem. Our main algorithmic contribution is an exact branch-and-bound algorithm, where each evaluation is accelerated by variant of Dijkstra's algorithm. A simple greedy heuristic is also proposed for comparisons. The evaluation and comparison are done on pieces of scientific applications from the Per-fectClub and the HLSynth95 benchmarks. The results demonstrate the suitability of these solutions for high-level synthesis scheduling.

- by Hadda Cherroun
- •
- Information Systems, Applied Mathematics, Operations Research, Linear Programming

In this paper, roughness was modelled as a pattern of parallelepipedic elements of height k periodically distributed on the plane walls of a microchannel of height H and of infinite span. Two different approaches were used to predict the influence of roughness on heat transfer in laminar flows through this microchannel. Three-dimensional numerical simulations were conducted in a computational domain based on the wavelength l. A one-dimensional model (RLM model) was also developed on the basis of a discrete-element approach and the volume averaging technique. The numerical simulations and the rough-layer model agree to show that the Poiseuille number Po and the Nusselt number Nu increase with the relative roughness. The RLM model shows that the roughness effect may be interpreted by using effective roughness heights k eff and k effq for predicting Po and Nu respectively. k eff and k effq depend on two dimensionless local parameters: the porosity of the rough-layer and the roughness height normalized with the distance between the rough elements. The present results show that roughness increases the friction factor more than the heat transfer coefficient (performance evaluation criteria < 1), for a relative roughness height expected in the fabrication of microchannels (k/(H/2) < 0.46) or k/D h < 0.11).

From quantitative measurement of the equilibrium terrace-width (`) distribution (TWD) of vicinal surfaces, one can assess the strength A of elastic step±step repulsions A/`2. Generally the TWD depends only onÃ A Â step stiffness=k B T 2. From ideas of¯uctuation phenomena, TWDs should be describable by the``generalized Wigner distribution'' (GWD), essentially a power-law in`/h`i times a``Gaussian decay'' in`/h`i. The power-law exponent is related simply toÃ. Alternatively, the GWD gives the exact solution for a mean-®eld approximation. The GWD provides at least as good a description of TWDs as the standard ®t to a Gaussian (centered at h`i). It works well for weak elastic repulsion strengthsÃ (where Gaussians fail), as illustrated explicitly for vicinal Pt(1 1 0). Application to vicinal copper surfaces con®rms the viability of the GWD analysis. The GWD can be treated as a two-parameter ®t by scaling`using an adjustable characteristic width. With Monte Carlo and transfer-matrix calculations, we show that for physical values ofÃ, the GWD provides a better overall estimate than the Gaussian models. We quantify how a GWD approaches a Gaussian for largeÃ and present a convenient, accurate expression relating the variance of the TWD toÃ. We describe how discreteness of terrace widths impacts the standard continuum analysis.

- by Ted Einstein
- •
- Mechanics, Statistical Mechanics, Thermodynamics, Crystal Growth

Woody debris in rivers can be a significant source of roughness and consequently influences flow at both the local and reach scale. In order to develop a better quantitative understanding of the interaction between wood in rivers and stream flow, we thus performed a set of field measurements of the drag on model woody debris for conditions that prevail in typical natural streams. Our model debris consisted of PVC ''logs'' with diameters between 4 and 30 cm. The field setting allowed us to consider the hydrodynamic influence of a rough stream bottom, and our measurements thus complement previously published flume-based measurements. We found that, owing to the variation of velocity with water depth, some of our results differed appreciably from measurements made in smooth flumes. We determined the effects of (i) the orientation of the log, (ii) the size of the log relative to the water depth, (iii) the depth of the log in the water column, and (iv) leafless branches on the log. We found that the orientation of the log had no significant effect on the apparent drag coefficient. By contrast, because the water velocity varies with depth, the position of the log in the water column influenced the apparent drag for small logs. For large logs (diameter >30% of the water depth), however, the position of the log had little effect on drag. The ratio of the diameter of the log to the water depth, a quantity called ''blockage,'' also affected drag. As blockage increased, drag increases. For blockages greater than about 0.3, however, the drag becomes independent of blockage. Finally, we found that the presence of leafless branches does not increase the drag (within measurement sensitivity). D

- by Michael Manga
- •
- Geology, Geomorphology, Stress, Models

In order to measure the D structure of a number of objects a comparably new technique in computer vision exists, namely time of flight (TOF) cameras. The overall principle is rather easy and has been applied using sound or light for a long time in all kind of sonar and lidar systems. However in this approach one uses modulated light waves and receives the signals by a parallel pixel array structure. Out of the travelling time at each pixel one can estimate the depth structure of a distant object. The technique requires measuring the intensity differences and ratios of several pictures with extremely high accuracy; therefore one faces in practice rather high noise levels. Object features as reflectance and roughness influence the measurement results. This leads to partly high noise levels with variances dependent on the illumination and material parameters. It can be shown that a reciprocal relation between the variance of the phase and the squared amplitude of the signals exists. On...

- by Bernhard Moser
- •
- Engineering, Geography, Computer Science, Computer Vision

A new empirical model for the retrieval, at a field scale, of the bare soil moisture content and the surface roughness characteristics from radar measurements is proposed. The derivation of the algorithm is based on the results of three experimental radar campaigns conducted under natural conditions over agricultural areas. Radar data were acquired by means of several C-band space borne

- by Monique Dechambre
- •
- Algorithms, Remote Sensing, Agriculture, Surface Roughness

The knowledge of the real area of contact plays an important role in metal forming processes as it influences friction and heat transfer in the tool-workpiece interface. In accurate finite element analysis, friction and heat transfer have to be faced by numerical interface models that consider the real contact area in dependence of the applied normal load. Up-to-date methods for the calculation of the real contact area-load relation are either oversimplified or too complex to be used in interface models. This paper presents a new method for evaluating the real contact area in dependence of the normal load that takes the material properties and real asperity slopes into consideration, and simplification (compared to e.g. the work of Neumaier [Zur Optimierung der Verfahrensauswahl von Kalt-, Halbwarm-und Warmmassivumformverfahren, Fortschritt-Berichte VDI: Reihe 2, Fertigungstechnik, vol. 637. Dü sseldorf: VDI Verlag, 2003] is achieved by making use of the statistical character of real surfaces. The main idea of the new concept is to obtain the real contact area-load relation by combining the bearing area curve and a model asperity with correct representation of the mean asperity slope.

- by B. Buchmayr and +2
- •
- Mechanical Engineering, Statistical Analysis, Modeling, Heat Transfer

This paper reports on the numerical modelling of flash flood propagation in urban areas after an excessive rainfall event or dam/dyke break wave. A two-dimensional (2-D) depth-averaged shallow-water model is used, with a refined grid of quadrilaterals and triangles for representing the urban area topography. The 2-D shallow-water equations are solved using the explicit second-order scheme that is adapted from MUSCL approach. Four applications are described to demonstrate the potential benefits and limits of 2-D modelling: (i) laboratory experimental dam-break wave in the presence of an isolated building; (ii) flash flood over a physical model of the urbanized Toce river valley in Italy; (iii) flash flood in October 1988 at the city of Nîmes (France) and (iv) dam-break flood in October 1982 at the town of Sumacárcel (Spain). Computed flow depths and velocities compare well with recorded data, although for the experimental study on dam-break wave some discrepancies are observed around buildings, where the flow is strongly 3-D in character. The numerical simulations show that the flow depths and flood wave celerity are significantly affected by the presence of buildings in comparison with the original floodplain. Further, this study confirms the importance of topography and roughness coefficient for flood propagation simulation.

- by Michael F Sheridan
- •
- Psychology, Natural Hazards, Natural Disasters, Simulation

A recent development in the use of lidar remote sensing techniques is ground-based laser scanning. Laser scanning of rock faces yields the spatial relation between all scanned rock surface points, at a very high resolution, basically a dense "point cloud" in three-dimensional space. The subject of this research is to obtain discontinuity information from the point cloud data set, using an approach that can be automated. The first step in this methodology is to interpolate the point cloud data using 3D Delaunay triangulation in order to create a 3D surface. As a 3D triangulated surface, the scanned rock face is represented by a large number of triangles. The orientation of each triangle can subsequently be computed using basic geometrical rules. Analysis of the kernel density stereo plots of the orientation of all triangles, reveal that specific discontinuity sets can be recognised. Obviously, if this approach can be further developed and fully automated, this would give the site engineer or geologist, in realtime, evidence on the internal structure of any discontinuous rock mass. Particularly in areas where access to rock outcrops is poor, application of this technique will be very promising.

- by Robert H R G K Hack
- •
- Rock Mechanics, Geotechnical Engineering, Laser, LiDAR

A novel ultrahydrophobic ultrathin film was prepared by stearic acid (STA) chemically adsorbed onto the polyethyleneimine (PEI) coated aluminum wafer. The formation and the structure of the films have been characterized by means of water contact angle measurement, ellipsometry, Fourier transformation infrared spectroscopy, and X-ray photoelectron spectroscopy. The static contact angle for water on the surface of this ultrathin organic film was measured to be as high as 166°. Apart from the hydrophobic STA monolayer, the needle-like surface nanostructures with enough roughness was found to be essential for the generation of ultrahydrophobicity. We suggest that a composite interface formed by the needle-like surface nanostructures, water droplet, and air trapped in the crevices is responsible for the superior water-repellent property.

The rapid proliferation of wireless networks and mobile computing applications has changed the landscape of network security. Anomaly detection is a pattern recognition task whose goal is to report the occurrence of abnormal or unknown behavior in a given system being monitored. This paper presents an efficient rough set based anomaly detection method that can effectively identify a group of

- by Ihn-Han Bae
- •
- Mathematics, Computer Science, Distributed Computing, Artificial Intelligence

The use of bonded fiber reinforced polymer (FRP) sheets for upgrade or repair of aging and deteriorating concrete structure has emerged as a viable and cost effective method. Previous research has identified several items that influence FRP-concrete bond strength including concrete strength, type of FRP laminate, the number of layers of the FRP laminate, and the bonding agent or epoxy saturant used. To date, limited research has been conducted on studying the influence of surface preparation (i.e. surface roughness) on bond performance. To that end, an experimental program was undertaken to investigate the effect of a broad range of surface roughnesses and putty thickness on bond strength. A laser profilometer device has been developed at the University of Missouri-Rolla that can characterize surface roughness using laser stripping and image analysis. This devise was used in conjunction with water-jet technology to create a broad range of surface roughnesses that were evaluated within the context of this study. The effects of surface roughness on bond performance for two different commercially available externally bonded laminate systems were investigated. These systems were separated into two series of tests. In total 62 specimens were produced, utilizing three test methods to study bond behavior, namely a flexure test and two surface tests (torsion and pull-off). The different grades of roughness were obtained from water jetting using the rotary jet method. The effect of surface roughness and putty thickness on the bond performance of FRP sheets to concrete is presented in this paper.

- by John Myers
- •
- Surface Roughness, Bond Strength, Fiber Reinforced Polymer, Roughness

Normal depth is an important parameter occurring in the design of irrigation canals. Direct analytic solution of normal-depth problems is not possible, as the governing equations for the practical canal sections are implicit. The solution requires tedious methods of trial and error. Tabular and graphical methods also available for solution are subject to errors of double interpolation and errors of judgment in reading the graphs. Furthermore, the methods are based on Manning's equation, which is valid for a hydraulically rough boundary having a narrow range of relative roughness and involves a roughness coefficient having awkward dimensions. Reported herein are explicit equations for normal depth in various irrigationcanal sections.

- by Prabhata Swamee
- •
- Civil Engineering, Design, Depth, Irrigation and Drainage Engineering

Burnishing is a chipless finishing method, which employs a rolling tool, pressed against the workpiece, in order to achieve plastic deformation of the surface layer. Recent developments made possible burnishing of heat-treated steel components up to 65 HRC. Features of burnishing include a good roughness (comparable to grinding), as well as improvement of mechanical characteristics of the surface (fatigue strength, corrosion resistance, and bearing ratio), due to implementation of compressive stresses into the surface layer. This paper will present influences of certain burnishing parameters upon roughness, for a hardened steel component (64 HRC).

- by Ioan Marinescu
- •
- Engineering, Technology, Physical sciences, Roughness

Landslides cause damage to property and unfortunately pose a threat even to human lives. Good landslide susceptibility, hazard, and risk models could help mitigate or even avoid the unwanted consequences resulted from such hillslope mass movements. For the purpose of landslide susceptibility assessment the study area in the central Slovenia was divided to 78 365 slope units, for which 24 statistical variables were calculated. For the land-use and vegetation data, multi-spectral highresolution images were merged using Principal Component Analysis method and classified with an unsupervised classification. Using multivariate statistical analysis (factor analysis), the interactions between factors and landslide distribution were tested, and the importance of individual factors for landslide occurrence was defined. The results show that the slope, the lithology, the terrain roughness, and the cover type play important roles in landslide susceptibility. The importance of other spatial factors varies depending on the landslide type. Based on the statistical results several landslide susceptibility models were developed using the Analytical Hierarchy Process method. These models gave very different results, with a prediction error ranging from 4.3% to 73%. As a final result of the research, the weights of important spatial factors from the best models were derived with the AHP method. Using probability measures, potentially hazardous areas were located in relation to population and road distribution, and hazard classes were assessed. D

- by Marko Komac
- •
- Geology, Geomorphology, Multivariate Statistics, Principal Component Analysis

The gate oxide reliability and the electrical behavior of FinFETs are directly related to the surface characteristics of the fin vertical sidewalls. The surface roughness of the fin sidewalls is one of the most important structural parameters to be monitored in order to optimize the fin patterning and postetch treatments. Because of the nanometer-scale dimensions of the fins and the vertical orientation of the sidewall surface, their roughness measurement is a serious challenge. In this paper, we describe a simple and effective method for measuring the sidewall morphology of silicon fins by conventional atomic force microscopy. The present methodology has been employed to analyze fins as etched by reactive ion etching and fins repaired by sacrificial oxidation. The results show that sacrificial oxidation not only reduces the roughness of the sidewalls, but also rounds the top corners of silicon fins. The present method can also be applied to characterize sidewall roughness of other nanostructures and materials such as the polysilicon gate of transistors or nanoelectromechanical beams.

- by Xiaohui Tang
- •
- Nanotechnology, Atomic Force Microscopy, Surface Roughness, Reliability

An uncertainty analysis of the unsteady flow component (UNET) of the one-dimensional model HEC-RAS within the generalised likelihood uncertainty estimation (GLUE) is presented. For this, the model performance of runs with different sets of Manning roughness coefficients, chosen from a range between 0.001 and 0.9, are compared to inundation data and an outflow hydrograph. The influence of variation in the weighting coefficient of the numerical scheme is also investigated. For the latter, the empirical results show no advantage of using values below 1 and suggest the use of a fully implicit scheme (weighting parameter equals 1). The results of varying the reach scale roughnesses shows that many parameter sets can perform equally well (problem of equifinality) even with extreme values. However, this depends on the model region and boundary conditions. The necessity to distinguish between effective parameters and real physical parameters is emphasised. The study demonstrates that this analysis can be used to produce dynamic probability maps of flooding during an event and can be linked to a stopping criterion for GLUE.

- by Florian Pappenberger
- •
- Hydrology, Prediction, Multidisciplinary, Probability

Since the wear of a grinding wheel has a direct effect on the workpiece vibration and both have effect on the workpiece quality, the main goal of this work is to study the relation between the process vibration signals and the workpiece quality (mean roughness, circularity and burning) as the grinding wheel gets worn, in an attempt to use these signals to decide the exact moment to dress the wheel. In order to reach this goal, several experiments were carried out in a plunge cylindrical grinding operation of an AISI 52100 quenched and tempered steel, having as input variables the dressing overlap ratio, the spark out time and the workpiece velocity. The output variables were the workpiece surface roughness and circularity and also the process vibration during both, the cutting phase and the spark out phase of the grinding cycle. The main conclusions were: (1) it is possible to have good workpiece quality even with a vibration level much higher than that obtained with a recently dressed wheel; (2) vibration during cutting phase and at the end of complete spark out can be used to monitor the wheel condition at least when high dressing overlap ratio is used; and (3) the decrease in the spark out time makes the vibration at the end of spark out increase a lot, but does not cause such a damage in surface roughness. This fact makes the use of partial spark out feasible in some situations. 

- by Amauri Hassui
- •
- Vibration, Surface Roughness, Optimization, Measurement

In this paper, vertical scanning interferometry (VSI) and atomic force microscopy (AFM) were used to characterize the topography of several nanofiltration and reverse osmosis membrane surfaces. Comparing roughness results from the two different characterization techniques revealed unique results for the various membrane surfaces. Roughness values tended to be higher from the interferometry measurements compared to those from AFM measurements for the same membranes. This was attributed to the inability of the AFM to capture dramatic changes in surface height of several microns or more. Based on interferometric measurements surface roughness was also found to increase with increasing scan-size up to a scan-size of 250,000 m 2 after which it remained relatively constant. Because such large scan-sizes are too large to be captured through AFM measurements interferometry appears to provide a more comprehensive characterization of membrane surface roughness.

- by İsmail Koyuncu
- •
- Engineering, Membrane Science, Atomic Force Microscopy, Surface Roughness

This paper presents a modification to conventional magnetron sputtering systems. The introduction of a grid in front of the target increases the metal ion ratio. Using OES and observing both Ti neutrals and ions, it was confirmed that the relative ionization could be qualitatively extended with grid-attached magnetron sputtering compared with a conventional magnetron system. On the other hand, the relative ionization of Ar decreased. Our results also show that the Ti films deposited by conventional magnetron exhibit (100) preferred orientation as the bias voltage increased. On the other hand, in the case of the grid-attached magnetron, the Ti films exhibit highly preferred (002) orientation with increasing bias voltage. The experiments clearly demonstrated that a dense Ti film with a smooth, specular reflecting surface can be produced using the grid-attached magnetron with increased Ti ion flux compared to the conventional magnetron.

- by Leonid Shaginyan
- •
- Engineering, Technology, Physical Vapor Deposition, Thin Films

There still remain three major technological lithography options for high volume manufacturing at the 32nm half pitch node: 193nm immersion lithography with high index materials, enabling NA>1.6 193nm double patterning and EUV lithography. In this paper the pros and cons of these three options will be discussed. Particular interest will be paid to the consequences of the final choice on the resist technology. High index 193nm immersion lithography also requires high index resist materials, which are under development but still far removed from the target refractive index and absorbance specifications not to mention lithographical performance. For double patterning the pitch may be relaxed, but the resists still need to be able to print very narrow lines and/or trenches. Moreover, it would be preferred for the resists to support pattern or image freezing techniques in order to step away from the litho-etch-litho-etch approach and make double patterning more cost effective. For EUV the resist materials need to meet very aggressive sensitivity specifications. In itself this is possible, but it is difficult to simultaneously maintain performance in terms of resolution and line width roughness. A new parameter (K LUP) for assessing resist performance in terms of these three performance criteria will be introduced.

- by eric hendrickx
- •
- Manufacturing, Refractive Index, Cost effectiveness, Lithography

This work focuses on the preparation of novel ternary transparent conducting oxide coatings on glass by the sol-gel method. The coatings were deposited by spin-coating from solutions of appropriate metal precursors and heat-treated at different heat-treatment procedures. An increase in electrical conductivity was achieved by a final forming gas treatment. Best electrical and optical properties have been obtained for coatings of crystalline Zn 2 SnO 4 , Zn 3 In 2 O 6 and Zn 5 In 2 O 8 and X-ray amorphous ZnSnO 3 with resistivities in the order of 10 − 2 -10 − 1 Ω cm, an average transmission in the visible of 85% and an average surface roughness of ∼ 1 nm. ZnGa 2 O 4 and GaSbO 4 coatings showed no electrical conductivity. For Zn 2 SnO 4 coatings, a restricted crystallite growth was observed probably due to phase segregation effects. Electrical properties of coatings in the system ZnO-In 2 O 3 were interpreted on the basis of the percolation theory.

- by Michel Aegerter
- •
- Engineering, Technology, Glass, Heat Treatment

The objective of this study was to determine some physical and mechanical properties of solid wood of wingnut (Pterocarya fraxinifolia (Lam.) Spach.) in comparison with major hardwood species in Turkey. In the study, some properties of plywood specimens produced from wingnut wood were also determined. Results showed that the characteristics of solid wingnut wood were comparable with some major hardwood species used in Turkey. Based on physical and mechanical properties tested, the wood could be consumed in some usage areas where high strength is not expected. Plywood from wingnut wood can be also used in various applications based on the mechanical properties tested. r

- by SAİP NAMİ KARTAL
- •
- Architecture, Building, Roughness, Building Environment

An evaluation of hydrogen silsesquioxane (HSQ) for EUV lithography is presented. The effects of bake temperature and developer concentration on the ultimate resolution, sensitivity and contrast are investigated. It is demonstrated that HSQ as a negative-tone photoresist provides patterns with half-pitches as small as 20 nm with EUV interference lithography. SEM micrographs show that the low line-edge roughness of the patterns is accompanied with the high-quality cross-sectional profiles. This high resolution and pattern quality are achieved through development in high-concentration developers for long development times, which is in line with previous results obtained with e-beam lithography.

- by yasin ekinci
- •
- Electron Beam Lithography, Microelectronic, Contrast, Contrast sensitivity

Glass bottles, traditionally coated with tin oxide and polyethylene, were obtained from a commercial production plant and their surface properties analysed. Atomic force microscopy (AFM) was used to image the surfaces of glass bottles and to estimate surface roughness. Scanning electron microscopy (SEM) studies of the coated glass surface showed features largely consistent with AFM images. Auger electron spectroscopy (AES) thickness studies on the coatings showed a direct correlation with measured coating thickness unit (CTU) thickness. Bottles were also tested by standard factory procedures for surface lubricity and internal bursting pressure. The surface and physical properties studies, in particular AFM, AES and internal bursting pressure, concluded that a hot-end coating thickness of~50 CTU or 7 nm provides optimum strength for these bottles.

Ice roughness, which has a major influence on in-flight icing heat transfer and, hence, ice shapes, is generally input from empirical correlations to numerical simulations. It is given as uniform in space, while sometimes being varied in time. In this paper, a predictive model for roughness evolution in both space and time during in-flight icing is presented. The distribution is determined mathematically via a Lagrangian model that accounts for the stochastic process of bead nucleation, growth, and coalescence into moving droplets and/or rivulets and/or water film. This general model matches well the spatial and temporal roughness distributions observed in icing tunnel experiments and is embedded in FENSAP-ICE, extending its applicability outside the range of airfoil types for which correlations exist. Thus, an additional important step has been taken toward removing another empirical aspect of in-flight icing simulation.

- by Giulio Croce
- •
- Engineering, Modeling, Heat Transfer, Interaction

The authors present a method to determine the rheological characteristics of debris flow directly. According to the authors' experiments on the material debris flow that occurred on Moscardo Torrent (Friuli Region, Italy), the debris flow behavior can be represented by a Herschel-Bulkley model with n = 1/3. In the authors' experiments, the coarse fraction of debris flow was eliminated, even in the large-scale rheological experiments. In practice, however, the rheological characteristics of debris flow are affected by the coarse particles. Zhao and Chen (1992) have researched the role of coarse particles in debris flow. In their research, the fine particle content of viscous debris flow is nearly the same as that of nonviscous debris flow, and different coarse particle content causes different concentration of debris flow. They gave a concept of effective concentration and pointed out that coarse particles reduce the space (or volume) occupied by fine particles and water, then raise the effective concentration of fine particle slurry, thus influencing indirectly the physical characteristics of debris flow. So the elimination of coarse fraction must affect the rheological characteristics of debris flow.

- by Prabhata Swamee
- •
- Civil Engineering, Water Supply, Hydraulic Engineering, Equation

Surface roughness (texture) has an effect on fluid flow in networks which has been studied for well over a century. The exact effect roughness has on fluid flow has not been completely understood, but a working estimate has been offered by a variety of authors over time. The work of Colebrook, Nikuradse, and Moody has provided practitioners with a method to include at least a first order estimate of roughness effects, but their work has been limited to relative roughness (roughness height to diameter) values of 5% or less. Modern fluidic systems at the mini-and micro-levels routinely violate the 5% relative roughness threshold due to the inability to control the roughness of surfaces to sufficient levels with respect to decreasing system scale. Current work by Kandlikar et al., has extended the traditional methods of assessing surface roughness effects up to 14% relative roughness by including the effect of constricted flow diameters (modified flow diameter based on constrictions caused by surface roughness) and modifying the Moody diagram to reflect new experimental data. The future of micro fluidics would suggest that trends for miniaturization will continue and that further understanding and experimentation will be warranted. This is especially true with regards to understanding the role of roughness on the flow in mini-and micro-channels.

- by Andres L Carrano
- •
- Mechanical Engineering, Applied Mathematics, Microfluidics, Surface Roughness

Human hair is a nanocomposite biological fiber. Maintaining the health, feel, shine, color, softness, and overall aesthetics of the hair is highly desired. Hair care products such as shampoos and conditioners, along with damaging processes such as chemical dyeing and permanent wave treatments, affect the maintenance and grooming process and are important to study because they alter many hair properties. Nanoscale characterization of the morphological, frictional, and adhesive properties (tribological properties) of hair are essential to evaluate and develop better cosmetic products, and to advance the understanding of biological and cosmetic science. The atomic/friction force microscope (AFM/FFM) has recently become an important tool for studying the micro/nanoscale properties of human hair. This thesis presents a comprehensive review of tribological properties of various hair and skin as a function of ethnicity, damage, conditioning treatment, and various environments. Nanotribological properties such as roughness, friction, adhesion, and wear are presented, as well as investigations of scale effects and directionality dependence on friction and adhesion.

- by carmen latorre
- •
- Atomic Force Microscopy, Adhesion, AFM, Hair

Swelling and shrinkage of sub-grade soils are critical factors contributing to increases in roughness and degradation of serviceability of highway pavements. Existing procedures for predicting swell are largely based on the potential vertical rise (PVR) procedure developed by McDowell in 1956. While the PVR procedure represents a major development in the design of pavements on expansive soils, instances of apparently over-conservative PVR predictions have led some designers to suggest revision or replacement of the existing procedure. This project reviews the basic assumptions of the existing PVR procedure and identifies the likely sources of the questionable predictions that have arisen in the past. An alternative procedure is presented that features rigorous modeling of both the moisture diffusion process that induces changes in suction within a soil mass and the deformations that occur in response to changes in suction. This alternative procedure includes provisions for measuring and/or estimating soil and environmental input parameters necessary for the predictions. A procedure for predicting the impact of soil deformations on pavement performance is also presented. The proposed procedure is applied to three study sections involving Texas roadways on expansive soils, and parametric studies are presented evaluating the effectiveness of various design measures including moisture barriers, lime treatment, and replacement of in situ sub-grade soils with "inert" soils.

- by Rifat Bulut
- •
- Soil Mechanics, Roughness, Serviceability, Parametric analysis

Process monitoring in machining constitutes machine performance and machine condition for performing the desired objective. The optimality and effect of machining parameters on machine performance monitoring in tangential and orthogonal turn-milling processes is been studied. Surface Roughness (Ra) and Surface Hardness (H) has been taken as machine performance responses and Tool Vibrations (VIB) as machine condition monitoring response. Laser Doppler Vibrometer (LDV) is used for online capturing of tool vibrations and is analyzed using VibSoft analyzer for processing Acousto-optic emissions (AOE). Single cut machining on A-axis of CNC Vertical Milling centre using HSS End Mill cutters is adopted. Process parameters like cutter (tool) speed, feed rate and depth of cut with constant rotation of workpiece on A-axis are chosen while machining Brass material under dry condition. Statistical design of experiments (DOE) based on Taguchi’s Orthogonal Array (OA) is adopted for experimentation and Signal-to-Noise Ratio (SN ratio) of the responses is used for finding optimality of process parameters. The influence and contribution of the process parameters on the responses is been studied with help of Analysis of Variance (ANOVA).

- by arun vikram k
- •
- ANOVA, Roughness, Laser Doppler Vibrometer, Turn-Milling

Abstract: This report documents our study of active balance in dynamic legged systems. The purpose of this research is to build a foundation of knowledge that can lead both to the construction of useful legged vehicles and to a better... more

- by Marc Raibert
- •
- Artificial Intelligence, Control, Stability, Balance

The hydraulic jump is the most encountered flow phenomenon in the field of hydraulic engineering. Its importance attracted the researchers to investigate the various problems associated to this important energy dissipator. The hydraulic jump was first investigated experimentally in 1818 by Bidone. In 1828, Belanger developed his famous equation for depth ratio of the hydraulic jump formed in rectangular smooth open channel, Chow (1959). From that upto now, so many researches have been published on the hydraulic jump. However, up to the knowledge of the author, no generalization for Belanger equation has been made. This paper presents a generalized form for Belanger equation based on the use of the 1-D momentum and continuity equations. The generalized equation can be used for rectangular prismatic and non-prismatic open channels either horizontal or sloping with or without bed roughness. The generalized equation contains some parameters that can not be determined theoretically. Thus, experimental data are needed in such cases. In this paper, the developed generalized Belanger equation for depth ratio is calibrated and verified using experimental data that collected from different sources. Typical situations where the equation can be applied include channels with steps, channels with sudden expansions, sloping channels with or without roughness elements, ….etc.

- by Abdelazim Negm
- •
- Hydraulics, Flow, Sill, Slope

For the fabrication of microfluidic devices based on SU-8, the wetting properties of the polymer surface need to be adjusted. We investigated the effects of wet chemical and plasma processes with respect to wetting properties, surface... more

- by Gregor Morfill and +1
- •
- Condensed Matter Physics, PHOTOELECTRON SPECTROSCOPY, Surface modification, Wettability

The results of a laboratory study of hydraulic jumps on corrugated beds are presented. Experiments were performed for a range of Froude numbers from 4 to 10. Three values of the relative roughness t/y 1 of 0.50, 0.43, and 0.25 were studied. It was found that the tailwater depth required to form a jump was appreciably smaller than that for the corresponding jumps on smooth beds. Further, the length of the jumps was about half of those on smooth beds. The integrated bed shear stress on the corrugated bed was about 10 times that on smooth beds. The axial velocity profiles at different sections in the jump were found to be similar, with some differences from the profile of the simple plane wall jet. The maximum velocity u m at any section in terms of the velocity U 1 of the supercritical stream was correlated with the longitudinal distance x in terms of L, which is the distance where u m ϭ0.5U 1 , and this relation was the same as that for jumps on smooth beds with the difference that L/y 1 was much smaller for jumps on corrugated beds. The normalized boundary layer thickness ␦/b, where b is the length scale of the velocity profile, was equal to 0.45 for jumps on corrugated beds compared to 0.16 for the simple wall jet. The results of this study show the attractiveness of corrugated beds for energy dissipation below hydraulic structures.

- by N.or Nallamuthu Rajaratnam
- •
- Civil Engineering, Boundary Layers, Energy efficiency, Depth

This paper investigates the machining parameters affecting the roughness of surfaces produced in hard turning process for three different materials like EN8 steel, Aluminium alloy and Copper alloy under dry conditions. Three parameters were selected for study: cutting speed, feed and material hardness. For the three materials like Aluminium alloy, copper alloy and EN8 steel impact of increase in feeds versus decrease in cutting speeds with constant depth of cut adopted to analyze the influence of these parameters on the generated surface roughness. Regression analysis using MINITAB software for all the three material turning operation data mining was used to create model for the prediction of the average surface roughness (Ra) in terms of cutting speed, feed and material hardness and 67.2 % of R 2 and 47.52% of R 2 (adj) were obtained.

- by arun vikram k
- •
- Minitab, Regression Analysis, Roughness, Engineering Materials

- by Paul Feautrier
- •
- Information Systems, Applied Mathematics, Operations Research, Linear Programming
- by Balbir Kaith
- •
- Materials Engineering, Chemical Engineering, Grafting, Composite Material

Aluminium alloys are some of the predominant metals in industrial applications such as production of heat exchangers, heat pumps. They have high heat conductivity coupled with a low specific weight. In cold working conditions, there is a risk of frost formation on the surface of aluminium in the presence of water vapour, which can lead to the deterioration of equipment performance. This work addresses the methods of surface modification of aluminium and their effect of the underlying surface morphology and wettability, which are the important parameters for frost formation. Three groups of real-life aluminium surfaces of different morphology: unpolished aluminium, polished aluminium, and aluminium foil, were subjected to surface modification procedures which involved the formation of a layer of hydrophilic hyperbranched polyethyleneglycol via in situ polymerization, molecular vapour deposition of a monolayer of fluorinated silane, and a combination of those. The effect of these surface modification techniques on roughness and wettability of the aluminium surfaces was elucidated by ellipsometry, contact angle measurements and atomic force microscopy. We demonstrated that by employing different types of surface modifications the contact angle of water droplets on aluminium samples can be varied from 12 • to more than 120 • . A crossover from Cassie-Baxter to Wenzel regime upon changing the surface roughness was also observed.

- by Alireza Afshari
- •
- Multidisciplinary, Surface modification, Contact angle, Roughness

The strength of a rock mass for foundation purposes is for a large part determined by the discontinuities in the rock mass. Numerical calculations of discontinuous rock masses prove often to be cumbersome and unreliable. Rock mass classification may be an equal or more reliable methodology. The Slope Stability Probability Classification (SSPC) system designed for slope stability may be used for this purpose. The system has been developed during four years of research in Falset, province Tarragona, Spain. The rock slope classification scheme assesses orientation dependent and orientation independent stability. The orientation independent stability assessment leads to a rock mass strength criterion based on classification data, e.g. intact rock strength, discontinuity spacing and discontinuity condition. The criterion is developed in the context of a slope stability classification system, however, there is no reason that the criterion is not also valid for the determination of rock mass strength for other purposes, such as foundations on a discontinuous rock mass. The results of the strength criterion are compared to the results of the ’modified Hoek-Brown strength criterion’ and to the rock mass strength as determined by Bieniawski’s classification system.

- by Robert H R G K Hack
- •
- Rock Mechanics, Geotechnical Engineering, Weathering, Discontinuity

Inconel 718 is a high nickel content super alloy possessing high strength at elevated temperatures and resistance to oxidation and corrosion. The non-traditional manufacturing process of Rotary ultrasonic machining (RUM) possesses many advantages over traditional machining during the manufacture of Inconel 718 parts. An experimental investigation was conducted to determine the main RUM parameters which contribute to effects the metal removal rate and surface roughness of Inconel 718. It was found that feed rate is the most critical parameter in RUM.