Changes of Surface Topography During Running-In Process

2004 ◽  
Vol 126 (3) ◽  
pp. 620-625 ◽  
Author(s):  
Yeau-Ren Jeng ◽  
Zhi-Way Lin ◽  
Shiuh-Hwa Shyu
Keyword(s):  
Surface Roughness ◽  
Theoretical Model ◽  
Surface Topography ◽  
Experimental Results ◽  
Wear Model ◽  
Initial Height ◽  
Different Types

This study investigated the surface topographical changes during running-in. A theoretical model, which is composed of Johnson translatory system and a microscopic wear model, was used to describe the changes of surface roughness during running-in for general surfaces. Running-in tests were conducted for engine bores with different surface height distributions in order to understand surface topographical changes and validate the theory. Experimental results show that the theoretical model provides a good indication of changes of surface topography for surfaces with different types of initial height distributions.

The Profile Development of a Twin-Land Oil-Control Ring During Running-In

1998 ◽  
Vol 120 (3) ◽  
pp. 616-621 ◽  
Author(s):  
M. Visscher ◽  
D. Dowson ◽  
C. M. Taylor
Keyword(s):  
Surface Roughness ◽  
Theoretical Model ◽  
Twist Angle ◽  
Theoretical Modeling ◽  
Experimental Results ◽  
Roughness Height ◽  
Profile Development ◽  
Motored Engine

This paper presents experimental results of motored engine tests on the wear and profile development of a twin-land oil-control ring. It is shown that the roughness height of the plateau honed liner decreases during running-in, indicating that the deeper grooves remain unaffected. The piston lands are much smoother, and do not show a significant overall change in surface roughness. The profile development results are compared with computer predictions in order to verify the theoretical modeling. It is indicated that the worn land profiles remain tapered, with an inclination resembling the twist angle of the ring. However, there remains a difference in the experimental and the numerically predicted land inclinations. This is probably due to the piston tilt, which was not included in the theoretical model.

On the Evaluation Method of Wavelet Analysis for Surface Roughness

2010 ◽  
Vol 44-47 ◽  
pp. 4077-4080
Author(s):  
Mei Fa Huang ◽  
Xiong Cheng ◽  
Bing Kuang ◽  
Jiang Tai Huang
Keyword(s):  
Surface Roughness ◽  
Wavelet Analysis ◽  
Surface Topography ◽  
Evaluation Method ◽  
Surface Profile ◽  
Experimental Results ◽  
Roughness Profile ◽  
Mallat Algorithm ◽  
New Generation

The quality of workpiece is influenced by the surface roughness. However, the assessment of parameters of surface roughness is not researched intensively in the new generation GPS standards system. This paper presents a method to assess parameters of surface roughness. The methodology adopts wavelet analysis to construct the model of surface topography and uses the mallat algorithm to separate roughness profile from surface topography. The assessment results of surface profile are calculated according to the standard ISO 4287:1997. The experimental results show that the method not only avoids simplicity the assessment of parameters, but also decreases the number of productions of mis-acceptance and mis-rejection.

Actuation and dynamic mechanical characteristics of a core free flat dielectric electro-active polymer soft actuator

2020 ◽  
Vol 14 (4) ◽  
pp. 7396-7404
Author(s):  
Abdul Malek Abdul Wahab ◽  
Emiliano Rustighi ◽  
Zainudin A.
Keyword(s):  
Theoretical Model ◽  
Resonance Frequency ◽  
Dynamic Testing ◽  
Experimental Results ◽  
Percentage Error ◽  
Initial Tension ◽  
Average Percentage ◽  
Soft Actuator ◽  
Average Percentage Error ◽  
Mechanical Dynamics

Various complex shapes of dielectric electro-active polymer (DEAP) actuator have been promoted for several types of applications. In this study, the actuation and mechanical dynamics characteristics of a new core free flat DEAP soft actuator were investigated. This actuator was developed by Danfoss PolyPower. DC voltage of up to 2000 V was supplied for identifying the actuation characteristics of the actuator and compare with the existing formula. The operational frequency of the actuator was determined by dynamic testing. Then, the soft actuator has been modelled as a uniform bar rigidly fixed at one end and attached to mass at another end. Results from the theoretical model were compared with the experimental results. It was found that the deformation of the current actuator was quadratic proportional to the voltage supplied. It was found that experimental results and theory were not in good agreement for low and high voltage with average percentage error are 104% and 20.7%, respectively. The resonance frequency of the actuator was near 14 Hz. Mass of load added, inhomogeneity and initial tension significantly affected the resonance frequency of the soft actuator. The experimental results were consistent with the theoretical model at zero load. However, due to inhomogeneity, the frequency response function’s plot underlines a poor prediction where the theoretical calculation was far from experimental results as values of load increasing with the average percentage error 15.7%. Hence, it shows the proposed analytical procedure not suitable to provide accurate natural frequency for the DEAP soft actuator.

Transition Times in Memory

2018 ◽  
Author(s):  
Donatella della Porta ◽  
Massimiliano Andretta ◽  
Tiago Fernandes ◽  
Eduardo Romanos ◽  
Markos Vogiatzoglou
Keyword(s):  
Theoretical Model ◽  
Social Movement ◽  
Transition Period ◽  
Two Dimensions ◽  
Democratic Regime ◽  
Organizational Models ◽  
Different Types ◽  
Transition Times ◽  
Movement Participation

The second chapter covers the main characteristics of transition time in the four countries: Italy, Greece, Spain, and Portugal. After developing the theoretical model on paths of transition, with a focus on social movement participation, the chapter looks at social movements and protest events as turning points during transition, covering in particular the specific movement actors, their organizational models, and their repertoires of action and frames. The chapter focuses on two dimensions: the role of mobilization in the transition period, which implies the analysis of how elites and masses interact, ally, or fight with each other in the process, and the outcome of transitions as continuity versus rupture of the democratic regime vis-à-vis the old one. It concludes by elaborating some hypotheses on how different modes of transition may produce different types and uses of (transition) memories.

scholarly journals How the Multiplicity of Suggested Information Affects the Behavior of a User in a Recommender System

Electronics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 741
Author(s):  
Yuseok Ban ◽  
Kyungjae Lee
Keyword(s):  
High Precision ◽  
Recommender System ◽  
Visual Information ◽  
Experimental Results ◽  
Supplementary Information ◽  
Digital Platform ◽  
Different Types ◽  
Types Of Information

Many researchers have suggested improving the retention of a user in the digital platform using a recommender system. Recent studies show that there are many potential ways to assist users to find interesting items, other than high-precision rating predictions. In this paper, we study how the diverse types of information suggested to a user can influence their behavior. The types have been divided into visual information, evaluative information, categorial information, and narrational information. Based on our experimental results, we analyze how different types of supplementary information affect the performance of a recommender in terms of encouraging users to click more items or spend more time in the digital platform.

Surface roughness and substrate induced symmetry-breaking: influence on the plasmonic properties of aluminum nanostructure arrays

Nanoscale ◽  
2020 ◽  
Author(s):  
Feifei ZHANG ◽  
Jérôme Plain ◽  
Davy Gerard ◽  
Jérôme Martin
Keyword(s):  
Surface Roughness ◽  
Optical Properties ◽  
Symmetry Breaking ◽  
Surface Topography ◽  
Metallic Nanoparticles ◽  
Far Field ◽  
Al Nanoparticles ◽  
Nanostructure Arrays

The surface topography is known to play an important role on the near- and far- field optical properties of metallic nanoparticles. In particular, aluminum (Al) nanoparticles are commonly fabricated through...

RELIABILITY ASSESSMENT OF AXIALLY COMPRESSED COMPOSITE CYLINDRICAL SHELLS WITH RANDOM IMPERFECTIONS

2011 ◽  
Vol 11 (02) ◽  
pp. 215-236 ◽  
Author(s):  
MATTEO BROGGI ◽  
ADRIANO CALVI ◽  
GERHART I. SCHUËLLER
Keyword(s):  
Mathematical Models ◽  
Axial Compression ◽  
Cylindrical Shells ◽  
Reliability Assessment ◽  
Buckling Analysis ◽  
Buckling Load ◽  
Experimental Results ◽  
Drastic Decrease ◽  
Different Types ◽  
Probability And Statistics

Cylindrical shells under axial compression are susceptible to buckling and hence require the development of enhanced underlying mathematical models in order to accurately predict the buckling load. Imperfections of the geometry of the cylinders may cause a drastic decrease of the buckling load and give rise to the need of advanced techniques in order to consider these imperfections in a buckling analysis. A deterministic buckling analysis is based on the use of the so-called knockdown factors, which specifies the reduction of the buckling load of the perfect shell in order to account for the inherent uncertainties in the geometry. In this paper, it is shown that these knockdown factors are overly conservative and that the fields of probability and statistics provide a mathematical vehicle for realistically modeling the imperfections. Furthermore, the influence of different types of imperfection on the buckling load are examined and validated with experimental results.

Influence of surface roughness on the wetting angle

1995 ◽  
Vol 10 (8) ◽  
pp. 1984-1992 ◽  
Author(s):  
X.B. Zhou ◽  
J.Th.M. De Hosson
Keyword(s):  
Surface Roughness ◽  
Gaussian Distribution ◽  
Rough Surfaces ◽  
Contact Angles ◽  
Wetting Angle ◽  
Experimental Results ◽  
Solid Surfaces ◽  
Roughness Measurements

A this paper the influence of surface roughness on contact angles in the system of liquid Al wetting solid surfaces of Al2O3 has been studied. It was observed that contact angles of liquid Al vary significantly on different rough surfaces of Al2O3. A model is proposed to correlate contact angles with conventional roughness measurements and wavelengths by assuming a cosine profile of rough grooves with a Gaussian distribution of amplitudes. In comparison with the experimental results, the model provides a good estimate for describing the influence of surface roughness on contact angles of liquid Al on Al2O3.

Etude par spectrométrie infrarouge de l'action de solvants aprotiques sur l'association ester–eau et ester–Ba2+. Discussion du rôle catalytique du solvant et de l'ion Ba2+ dans l'hydrolyse alcaline du propionate de methyle

1979 ◽  
Vol 57 (4) ◽  
pp. 400-403 ◽  
Author(s):  
Anne Le Narvor ◽  
Pierre Saumagne
Keyword(s):  
Ir Spectra ◽  
Charge Density ◽  
Carbonyl Group ◽  
Alkaline Hydrolysis ◽  
Experimental Results ◽  
Methyl Propionate ◽  
Orbital Control ◽  
Different Types ◽  
Kinetics Of ◽  
Better Than

The ir spectra of mixtures of methyl propionate/water and methyl propionate/Ba2+ in dimethylsulfoxide and in acetonitrile have been recorded in the region of the νCO mode of the ester. Evidence is presented to indicate the presence of different types of complexes; their concentration was determined as a function of the composition of the medium. The spectroscopic results are compared to those from the kinetics of the alkaline hydrolysis in the same conditions. It is demonstrated that the orbital control explains the experimental results better than does the charge density on the carbon of the carbonyl group. [Journal translation]

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