3D Multi-Scale Topography Analysis in Specifying Quality of Honed Surfaces

2008 ◽  
Author(s):  
Leila Sabri ◽  
Sabeur Mezghani ◽  
Mohamed El Mansori ◽  
Jean-Vincent Le Lan ◽  
Tommaso Dal Negro
Keyword(s):  
Surface Characteristics ◽  
Process Variables ◽  
Oil Consumption ◽  
Machining Processes ◽  
Multi Scale ◽  
Continuous Wavelets ◽  
Multi Stage ◽  
Topographic Parameter ◽  
Cylinder Liners

The quality of the surface texture on cylinder liners of engines has an important influence on oil consumption and running performance. This texture is generated with a succession of three honing operations (rough, finishing and plateau honing). These honing steps are difficult to optimize due to the large number of process variables (Velocity of the rotational motion, velocity of the axial motion ...) and their complex interrelation. This paper discusses the use of the multiscale topographic parameter of the honing process as a new concept to identify the relation between the process variables and the resulting performances in terms of form and surface finish. To achieve this objective, a multi-scale decomposition method of surface topography based on 2D continuous wavelets transform was performed to analyze the evolution of the topographic honing. This approach also shows a good indication of the dependence between the honing steps and the roughness scales. Finally, it provides an efficient tool to predict the surface characteristics corresponding to given process variables and can be extended to optimize other multi-stage abrasive machining processes.

scholarly journals The Effects of Slicing Parameters on Surface Quality of European Beech Wood

2021 ◽  
Vol 72 (1) ◽  
pp. 57-63
Author(s):  
Agnieszka Jankowska ◽  
Paweł Kozakiewicz ◽  
Marcin Zbieć
Keyword(s):  
Contact Angle ◽  
Surface Quality ◽  
Wood Surface ◽  
Beech Wood ◽  
European Beech ◽  
Surface Characteristics ◽  
Machining Processes ◽  
Fagus Sylvatica L ◽  
Pressure Bar

The main objective of this work was to evaluate the effects of flat slicing processes on wood surface characteristics of the European beech (Fagus sylvatica L.). The relation between wettability, roughness and machining methods were studied. Two different wood thickness (3.4 and 4.0 mm) and three levels of compression during slicing (67.5 %, 57.5 % and 47.5 % of desired veneer thickness) were used to prepare surfaces prior to testing. The smaller variation of the thickness of thinner veneers was observed. No significant impact of compression on variation of the thickness was found. The contact angle was lower when roughness measured parallel to the grain was higher. The influence of selected compression on roughness of European beech veneers measured perpendicular to the grain was confirmed. This indicated that the influence of the set of machining processes, such as pressure bar setting during slicing, is significant for wooden veneers surface properties.

scholarly journals Detection of Myocardial Infarction Using ECG and Multi-Scale Feature Concatenate

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1906
Author(s):  
Jia-Zheng Jian ◽  
Tzong-Rong Ger ◽  
Han-Hua Lai ◽  
Chi-Ming Ku ◽  
Chiung-An Chen ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Network Structure ◽  
Class Imbalance ◽  
Class Imbalance Problem ◽  
Multi Scale ◽  
Imbalance Problem ◽  
Average Accuracy ◽  
Significant Difference ◽  
Electrocardiogram Ecg

Diverse computer-aided diagnosis systems based on convolutional neural networks were applied to automate the detection of myocardial infarction (MI) found in electrocardiogram (ECG) for early diagnosis and prevention. However, issues, particularly overfitting and underfitting, were not being taken into account. In other words, it is unclear whether the network structure is too simple or complex. Toward this end, the proposed models were developed by starting with the simplest structure: a multi-lead features-concatenate narrow network (N-Net) in which only two convolutional layers were included in each lead branch. Additionally, multi-scale features-concatenate networks (MSN-Net) were also implemented where larger features were being extracted through pooling the signals. The best structure was obtained via tuning both the number of filters in the convolutional layers and the number of inputting signal scales. As a result, the N-Net reached a 95.76% accuracy in the MI detection task, whereas the MSN-Net reached an accuracy of 61.82% in the MI locating task. Both networks give a higher average accuracy and a significant difference of p < 0.001 evaluated by the U test compared with the state-of-the-art. The models are also smaller in size thus are suitable to fit in wearable devices for offline monitoring. In conclusion, testing throughout the simple and complex network structure is indispensable. However, the way of dealing with the class imbalance problem and the quality of the extracted features are yet to be discussed.

scholarly journals The Impact of Post-Manufacture Treatments on the Surface Characteristics Important for Finishing of OSB and Particleboard

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 975
Author(s):  
Antonio Copak ◽  
Vlatka Jirouš-Rajković ◽  
Nikola Španić ◽  
Josip Miklečić
Keyword(s):  
Water Vapour ◽  
Oriented Strand Board ◽  
Construction Material ◽  
Surface Characteristics ◽  
Surface Treatments ◽  
Factors Affecting ◽  
Treatment Conditions ◽  
Water Vapour Absorption ◽  
The Impact

Oriented strand board (OSB) is a commonly used structural wood-based panel for walls and roof siding, but recently the industry has become interested in OSB as a substrate for indoor and outdoor furniture. Particleboard is mainly used in furniture productions and has become popular as a construction material due to its numerous usage possibilities and inexpensive cost. Moisture is one of the most important factors affecting wood-based panel performance and the post-treatment conditions affected their affinity to water. When OSB and particleboard are used as substrates for coatings, their surface characteristics play an important role in determining the quality of the final product. Furthermore, roughness can significantly affect the interfacial phenomena such as adsorption, wetting, and adhesion which may have an impact on the coating performance. In this research particleboard and OSB panels were sanded, re-pressed and IR heated and the influence of surface treatments on hardness, roughness, wetting, water, and water vapour absorption was studied. Results showed that sanding improved the wetting of particleboard and OSB with water. Moreover, studied surface treatments increased water absorption and water penetration depth of OSB panels, and re-pressing had a positive effect on reducing the water vapour absorption of particleboard and OSB panels.

Solution to Inverse Problem of Manufacturing by Surface Modification With Controllable Surface Integrity Correlated to Performance: A Case Study of Thermally Sprayed Coatings for Wear Performance

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
X. P. Zhu ◽  
P. C. Du ◽  
Y. Meng ◽  
M. K. Lei ◽  
D. M. Guo
Keyword(s):  
Inverse Problem ◽  
Surface Modification ◽  
Surface Integrity ◽  
High Performance ◽  
Surface Characteristics ◽  
Spray Angle ◽  
Functional Surface ◽  
Machining Processes ◽  
Wear Performance ◽  
Surface Features

Inverse problem of manufacturing is studied under a framework of high performance manufacturing of components with functional surface layer, where controllable generation of surface integrity is emphasized due to its pivotal role determining final performance. Surface modification techniques capable of controlling surface integrity are utilized to verify such a framework of manufacturing, by which the surface integrity desired for a high performance can be more effectively achieved as reducing the material and geometry constraints of manufacturing otherwise unobtainable during conventional machining processes. Here, thermal spraying of WC–Ni coatings is employed to coat stainless steel components for water-lubricated wear applications, on which a strategy for direct problem from process to performance is implemented with surface integrity adjustable through spray angle and inert N2 shielding. Subsequently, multiple surface integrity parameters can be evaluated to identify the major ones responsible for wear performance by elucidating the wear mechanism, involving surface features (coating porosity and WC phase retention) and surface characteristics (microhardness, elastic modulus, and toughness). The surface features predominantly determine tribological behaviors of coatings in combination with the surface characteristics that are intrinsically associated with the surface features. Consequently, the spray process with improved N2 shielding is designed according to the desired surface integrity parameters for higher wear resistance. It is demonstrated that the correlations from processes to performance could be fully understood and established via controllable surface integrity, facilitating solution to inverse problem of manufacturing, i.e., realization of a material and geometry integrated manufacturing.

The Cooling Rate Effect on Graphene Synthesis Using Low Pressure Chemical Vapor Deposition

2021 ◽  
Author(s):  
Byoungdo Lee ◽  
Weishen Chu ◽  
Wei Li
Keyword(s):  
Chemical Vapor Deposition ◽  
Reaction Time ◽  
Carbon Source ◽  
Cooling Rate ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Feeding Time ◽  
Process Variables ◽  
Pressure Chemical

Abstract Low-pressure chemical vapor deposition (LPCVD) is the most efficient method to synthesize large-scale, high-quality graphene for many potential applications such as flexible electronics, solar cells, and separation membranes. The quality of LPCVD is affected by process variables including methane/hydrogen (CH4/H2) ratio, time, pressure, temperature, and cooling rate. The cooling rate has been recognized as one of the most important process variables affecting the amount of carbon source, nucleation, reaction time, and thus the quality of the LPCVD. In this research, we investigate the effect of cooling rate on the quality of graphene synthesize by changing the cooling rate and the gas feeding time. Graphene coverage is measured by Raman mapping. It is found that fast cooling rate leads to decreased carbon source reaction time, which in turn results in higher coverage by monolayer graphene. The temperature-dependent gas feeding time corresponding to different cooling rates can be used to properly supply the carbon source onto the copper surface, also leading to a higher graphene coverage.

Schneidkantenpräparation von VHM-Mikrofräsern*/Cutting edge preparation of cemented carbide micro milling tools – A comparison of different fine machining processes

2015 ◽  
Vol 105 (11-12) ◽  
pp. 805-811
Author(s):  
E. Uhlmann ◽  
D. Oberschmidt ◽  
A. Löwenstein ◽  
M. Polte ◽  
I. Winker
Keyword(s):  
Tool Wear ◽  
Milling Process ◽  
Cutting Edge ◽  
Micro Milling ◽  
Machining Processes ◽  
Process Reliability ◽  
Cutting Edge Preparation ◽  
Milling Tools ◽  
Edge Preparation

Die Prozesssicherheit beim Mikrofräsen lässt sich mit einer gezielten Schneidkantenverrundung erheblich steigern. Dabei werden durch verschiedene Präparationstechnologien unterschiedliche Geometrien und Einflüsse auf den Fräsprozess erzeugt. Der Fachbeitrag behandelt den Einsatz präparierter Mikrowerkzeuge in Zerspanversuchen, in denen auf die Zerspankräfte, den Verschleiß sowie die Oberflächengüten eingegangen wird. &nbsp; Process reliability in micro milling can be increased by a defined cutting edge preparation. Different cutting edge preparations cause different effects on tool behavior in the downstream micro milling process. In this paper, the process forces, the tool wear and the surface quality of prepared micro milling tools are characterized in cutting tests.

DISTRIBUTION INCENTIVE SYSTEM FOR ELECTRICAL COMPANIES

2021 ◽  
Vol 4 (5) ◽  
pp. 43-48
Author(s):  
Yu. V. NIKITOCHKINA ◽  
Keyword(s):  
Optimization Method ◽  
Incentive System ◽  
New Model ◽  
Incentive Model ◽  
Multi Stage ◽  
Commercial Enterprise ◽  
Product Image

This article proposes a new model for stimulating distributors – a multi-stage scale that compares the distributor's rating with the percentage level of discount for regional coverage and specialization. The list of indicators for calculating discounts by specialization and regional coverage includes a group of indicators to increase the motivation of the distributor to improve the quality of their work and a group of indicators to increase the motivation of the distributor to expand the scope of action. Using the method of index grouping of expert estimates, the weight values of each indicator were found. The task of calculating the evaluation of the results of the distribution was set as a multi-criteria task, in which the additive optimization method was used for the procedure of folding private criteria, which was preceded by checking all private criteria for addi-tive independence. The developed incentive model can be adapted for any commercial enterprise interested in promoting its product through regional coverage, as well as in supporting the product image, which, of course, contributes to stimulating demand and increasing sales.

Investigating the relationship between housing satisfaction and quality of life in the decayed historic areas of Isfahan using path diagram

2017 ◽  
Vol 27 (5) ◽  
pp. 645-657 ◽  
Author(s):  
Esfandiar Zebardast ◽  
Homayoon Nooraie
Keyword(s):  
Quality Of Life ◽  
Sampling Technique ◽  
Housing Quality ◽  
Housing Satisfaction ◽  
Space Factor ◽  
Path Diagram ◽  
Multi Stage ◽  
Historic Areas ◽  
The Relationship

The aim of this paper is to survey the decayed historic areas of Isfahan (DHI) in order to determine the relationship between housing satisfaction and quality of life. The related literature on quality of life was reviewed and WHOQOL-BREF model was selected for measuring the quality of life as a whole; also, 17 indicators depicting the housing domain of quality of life were chosen for the purposes of this study. A multi-stage sampling technique was applied to data collection. For data analysis, firstly, the data obtained on 17 indicators of housing domain of quality of life were analysed using factor analysis. The factors extracted are housing quality, housing space, security of tenure and housing affiliation. Secondly, a path diagram was applied to obtain the relation between housing satisfaction sub-domains and the domains of quality of life as a whole. The results indicate that the housing space was the most effective sub-domain of housing on the domains of quality of life as a whole. We also found that in order to improve the housing domain of quality of life in the DHI, due attention should be paid to housing quality factor and to improve quality of life as a whole in these areas, it is also necessary to pay attention to housing space factor.

scholarly journals Analysis of Forces in Vibro-Impact and Hot Vibro-Impact Turning of Advanced Alloys

2011 ◽  
Vol 70 ◽  
pp. 315-320 ◽  
Author(s):  
Riaz Muhammad ◽  
Agostino Maurotto ◽  
Anish Roy ◽  
Vadim V. Silberschmidt
Keyword(s):  
Finite Element ◽  
Cutting Forces ◽  
Three Dimensional ◽  
Element Model ◽  
Machining Process ◽  
Strain Rates ◽  
Machining Processes ◽  
Machined Surface ◽  
Cutting Zone

Analysis of the cutting process in machining of advanced alloys, which are typically difficult-to-machine materials, is a challenge that needs to be addressed. In a machining operation, cutting forces causes severe deformations in the proximity of the cutting edge, producing high stresses, strain, strain-rates and temperatures in the workpiece that ultimately affect the quality of the machined surface. In the present work, cutting forces generated in a vibro-impact and hot vibro-impact machining process of Ti-based alloy, using an in-house Ultrasonically Assisted Turning (UAT) setup, are studied. A three-dimensional, thermo-mechanically coupled, finite element model was developed to study the thermal and mechanical processes in the cutting zone for the various machining processes. Several advantages of ultrasonically assisted turning and hot ultrasonically assisted turning are demonstrated when compared to conventional turning.

Low Environmental Impact Machining Processes of Composite Materials Applied to the Aerospace Sector

2010 ◽  
Vol 107 ◽  
pp. 15-19 ◽  
Author(s):  
Miguel Álvarez ◽  
Moisés Batista ◽  
Jorge Salguero ◽  
Manuel Sánchez-Carrilero ◽  
Mariano Marcos Bárcena
Keyword(s):  
Evaluation Process ◽  
Advanced Materials ◽  
Surface Finishing ◽  
Matrix Composites ◽  
Machining Processes ◽  
Tool Materials ◽  
Industrial Sectors ◽  
Aerospace Sector ◽  
Aeronautical Industry

In the last decades, technologically innovative processes performed in advanced materials such as Carbon Fibre (CF) and Metal Matrix Composites (MMC) have continuously increased because of these materials find increasingly applications in the most of the industrial sectors, particularly in aeronautical industry. This is caused by their excellent relationship weight/mechanical properties. Although there is a high trend to apply and develop non-conventional technologies and methods for machining CF and MMC, other common machining processes are commonly applied for working these materials. Thus, in aeronautical industry, mechanical drilling processes are usually applied for preparing the manufactured elements to be assembled. However, drilling of CF based materials can carry on troubles related to a loss of surface finishing quality and/or quick and high tool wear. This work reports on the results about an evaluation process of the surface quality of drilled CF samples as a function of the cutting conditions and the tool materials.

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