bluuebunny/crossref_metadata_2025_split huggingface dataset:
Film/Substrate Adhesion Assessment by Scratch Tests Performed With Different Indenters
Authors: Le Houérou Vincent , Jacomine Leandro , Gauthier Christian 
Published: October 2014

In most cases, scratching of the surface of a polymeric glass elicits brittle behavior and industrial solutions like coating have been successfully used to improve the scratch resistance. The origin of the success of the coating technique is still of great research interest since one of the limitations of this technique is the risk of cracking and chipping. In terms of interfacial adhesion characterization, a wide variety of methods have been used to assess this property of material systems. Nevertheless, the adhesion of coatings still remains to be successfully determined in a test which can reproduce the damage undergone by the coated surface during its real lifetime. In this context, scratch test constitutes a good candidate. The present study deals with the scratching technique as an interfacial adhesion measurement in coated systems.
Using a single-asperity scratching device allowing in-situ observation of the scratch, the fracture of a thin nano-composite coating deposited on its substrate was investigated under different conditions of temperature and scratching speed. Four types of fracture kinetics were observed depending on these two variables. One of these exhibits a stable blister growth at the same speed as the movement of the indenter over hundreds micrometers. This slow and extensive growth of a blister was obtained at 80 °C at a scratching speed of 10 μm/s. When the blister has reached a certain size, it propagates with the indenter without increasing further in size: it constitutes the steady state blister growth.
A variational form of the energy balance of a blistering process is proposed, which permits to assess the adhesion of the system. Actually, the energy spent in the delamination process can be determined by following the delaminated area during the blistering process with regard to the scratching distance. The main difficulty is to estimate the energy dissipated in plastic flow. Different tests were conducted with various indenters: spheres with different radius and roughness. Thanks to this multi-criterion approach, it was possible to fit a unique value of the adhesion in the case of experimental stable blistering growths. The results are discussed with regard to reliability and probe characteristics.
Vibration Isolation by Compliant Sensor Mounting Applied to a Coriolis Mass-Flow Meter
Authors: van de Ridder L. (Bert) , Hakvoort Wouter B. J. , van Dijk Johannes 
Published: October 2014

In this paper a vibration isolated design of the Coriolis Mass-Flow Meter (CMFM) is proposed, by introducing a compliant connection between the casing and the tube displacement sensors with the intention to obtain a relative displacement measurement of the fluid conveying tube, dependent on the tube actuation and mass-flow, but independent of casing excitations.
Analyses are focussed on changing the transfer function of support excitations to the relative displacement measurement. The influence of external vibrations on a compliant sensor element and the tube are made equal by tuning the resonance frequency and damping of the compliant sensor element and therefore the influence on the relative displacement measurement is minimised. Based on simulation results, a prototype is built and validated.
The validated design show a 20dB reduction of the influence of external vibrations on the mass-flow measurement value of a CMFM, without affecting the sensitivity for mass-flow.
Bearing Natural Degradation Detection in a Gearbox: A Comparative Study of the Effectiveness of Adaptive Filter Algorithms and Spectral Kurtosis
Authors: Elasha Faris , Ruiz-Carcel Cristobal , Mba David 
Published: October 2014

Bearing faults detection at the earliest stages is vital in avoiding future catastrophic failures. Many traditional techniques have been established and utilized in detecting bearing faults, though, these diagnostic techniques are not always successful when the bearing faults take place in gearboxes where the vibration signal is complex; under such circumstances it may be necessary to separate the bearing signal from the complex signal.
The objective of this paper is to assess the effectiveness of an adaptive filter algorithms compared to a Spectral Kurtosis (SK) algorithm in diagnosing a bearing defects in a gearbox. Two adaptive filters have been used for the purpose of bearing signal separation, these algorithms were Least Mean Square (LMS) and Fast Block LMS (FBLMS) algorithms.
These algorithms were applied to identify a bearing defects in a gearbox employed for an aircraft control system for which endurance tests were performed. The results show that the LMS algorithm is capable of detecting the bearing fault earlier in comparison to the other algorithms.
Transient Free Convection in a Rectangular Water-Filled Enclosure
Authors: Dubovsky Vadim , Kugler Yonatan , Maoz Nimrod , Letan Ruth 
Published: October 2014

Transient laminar free convection in a water-filled rectangular enclosure has been studied experimentally and numerically. The study aimed at gaining an insight into the physical phenomena, illustrated by the flow patterns and the temperature stratification, from the initial stage of a homogeneous fluid through the transient evolving process.
The experimental setup consisted of two rectangular water-filled enclosures: the smaller one contained a heat source and was centrally immersed in the larger one. Dye was injected for visualization of the rising boundary layer over the inner container walls, and the accumulation of the colored layers in the upper zone of the outer container. Simultaneously, the temperature measurements, by thermocouples and an infra-red camera, displayed the formation of a stratified structure.
The numerical study was conducted three-dimensionally, using the Fluent 6.3 software. The stratified temperature field, observed experimentally, was well-predicted by the numerical model.
The heat transfer rates and the transient averaged Nusselt numbers were compared with the data in the literature. The current, constant power input yielded Nu/Ra0.25∼0.7 in the range of Fo/Ra0.25 = 0–3.
Diffusion Measurements Using DOE Schardin’s Schlieren #2 Technique
Authors: Ambrosini Dario , De Leo Cinzia , Paoletti Domenica , Galli Giorgio 
Published: October 2014

The diffusion process is very important in many engineering applications. However, there is a shortage of data about diffusion, especially between liquid mixtures (such as water and glycerin, water and salt, etc.), which justifies the search for simple and accurate experimental techniques.
Optical techniques are recognized as powerful tools to investigate fluid flow phenomena in transparent media.
The aim of this paper is the development of an optical experimental technique, based on Diffractive Optical Element (DOE) Schardin’s schlieren # 2, for measuring liquid diffusion coefficient. This technique is then coupled to a new data treatment, based on correlation algorithms of the Particle Image Velocimetry (PIV) type, allowing the use of displacements recorded in the entire cell rather than just between two points.
Principles of the method and preliminary experimental results for the diffusion of a 1.75 M (moles/l) aqueous solution of common salt (NaCl) in pure water are given. These results are in good agreement with the literature.
Managing the Conceptualization Process in Innovative Engineering Design, Demonstrated on a Hybrid Two-Wheeler Design Case Study
Authors: Roser Holger M. , Walker Paul D. 
Published: October 2014

The process of conceptualizing innovative designs is multifaceted and inherently difficult to perform successfully. It is largely characterized by the designer’s capability to find solutions to design problems beyond existing norms. General agreement suggests this process should entail a holistic approach for conceiving new ideas, which are expanded, assessed, developed, refined, and implemented as part of an iterative problem solving cycle. Suitable design procedures and skills are therefore vital as most of the final cost of a product or system is committed within the early conceptualization stage.
This paper builds on engineering design techniques previously developed by the author, namely the Design Process Framework in conjunction with the Concept Assessment Taxonomy (CAT) at the heart of concept development [1]. The main emphasis of the work presented herein is the application of said framework to a new design challenge in order to further test and demonstrate its practicality in a real world context: the conceptual development of an innovative, modular, hybrid-electric powertrain for two-wheelers.
Reverse Engineering Using Close Range Photogrammetry for Additive Manufactured Reproduction of Egyptian Artefacts and Other Objets d’art
Authors: Kaufman John , Rennie Allan E. W. , Clement Morag 
Published: October 2014

Photogrammetry has been in use for over one hundred and fifty years. This research considers how digital image capture using a medium range Nikon Digital SLR camera, can be transformed into 3D virtual spatial images, and together with additive manufacturing (AM) technology, geometric representations of the original artefact can be fabricated. The research has focused on the use of photogrammetry as opposed to laser scanning (LS), investigating the shift from LS use to a Digital Single Lens Reflex (DSLR) camera exclusively.
The basic photogrammetry equipment required is discussed, with the main objective being simplicity of execution for eventual realisation of physical products. As the processing power of computers has increased and become widely available, at affordable prices, software programs have improved, so it is now possible to digitally combine multi-view photographs, taken from 360°, into 3D virtual representational images. This has now led to the possibility of 3D images being created without LS intervention.
Two methods of digital data capture are employed and discussed, in acquiring up to 130 digital data images, taken from different angles using the DSLR camera together with the specific operating conditions in which to photograph the objects. Three case studies are documented, the first, a modern clay sculpture, whilst the other two are 3000 year old Egyptian clay artefacts and the objects were recreated using AM technology. It has been shown that with the use of a standard DSLR camera and computer software, 2D images can be converted into 3D virtual video replicas as well as solid, geometric representation of the originals.
Research on External and Internal Induction Heating Effectiveness of Injection Molds by Means of Thermovision Measurements
Authors: Mrozek Krzysztof , Staniek Roman , Szostak Marek 
Published: October 2014

The aim of this work is to compare the effectiveness of two induction heating methods of injection molds by means of thermovision measurement. The problem of selecting external or internal induction heating for thin-walled moldings used in electrical and electronic industry is taken into consideration. At first, the boundary conditions were defined. Then a group of three moldings with different defects were selected. The defects that have been taken to remove by means of induction heating are: weld lines, breaking hinges, air traps and diesel effect. In order to compare the methods of heating two models were created. The first one was made as a block of steel with milled grooves with a width of 2mm and a depth varying from 1 to 12mm. The second model consisted of two parts, one being placed in the second.
The research stand consisted of prepared models, induction generator with power of 10kW, specially shaped inductor, thermovision camera and temperature sensor of PT100 type as a reference. First, the surface with milled grooves was heated in four different sectors (because of the shape of inductor) in time of 2s. The area of low-depth grooves heated up to 154°C while the surface with 12 mm grooves heated up to 120°C. It comes from eddy currents flowing. This phenomenon shows that effectiveness of external heating of grooved surface decreases with increasing of grooves depth.
In the second case the cavity insert was heated as a coil inside the inductor which was located inside the mold. The measured value was the time of heat transfer from heated area to the forming surface in three configurations.
Coupling a Linear Pressure and Mass Flow Frequency Model Obtained From Measurements at the Intake of an IC Engine With a Non-Linear Time Domain Code
Authors: Mezher Haitham , Chalet David , Migaud Jérôme 
Published: October 2014

Engine simulation software has become synonymous with automotive design and component development. An integral part of any engine simulation is the correct modeling of the air flow at the intake. This air flow, which is highly compressible and unsteady, has a first order influence on the trapped air mass inside the cylinder and therefore on the behavior of the engine (torque response and emissions). The non-linear modeling of the air paths at the intake is done using a space-time meshing and by solving the 1D equations with a proper time scheme. Such methods are the bases of today’s engine simulation codes [1]. The main constraint with these methods is the time needed to model complex geometries, whether being the simulation time or the time spent on calibrating the said models with experimental measurements. These complicated geometries become problematic to accurately predict, particularly the charge air cooler (CAC) which is responsible for cooling the air flow on a turbocharged engine.
Another approach is to use frequency domain models to describe the fluctuating pressure and mass flow [2]. Although this approach is simpler, faster in terms of computing time and offers many experimental techniques to characterize complicated geometries; important limitations can appear when it is confronted to the effects of high pressure levels and pulsating mass flow. Furthermore, the models behind such methods are designed to be used in the frequency domain, contrary to an engine simulation that works solely with time domain variables.
In this article, a linear frequency domain model known as a transfer matrix is used. This concept is nothing new in acoustics; however here it was developed by experimentally measuring the transfer matrix [3] for a simple tube on a dedicated bench under conditions similar to those encountered on an engine [4]. The approach is then extended to measure the transfer matrix of a charge air cooler (CAC) on a real engine test bench. The measured discrete transfer matrix, defined in terms of fluctuating pressure and mass flow, is then transformed to a continuous frequency model and coded in Simulink®. The latter is coupled to the non-linear engine simulation software GT-Power®.
The objective is to accurately model the pressure and mass flow of a complicated geometry using experimental measurements and a linear frequency model then to couple the transfer matrix to an engine simulation code, thus replacing the need for a meshed model.
Optimization of Machining Surplus Distribution Relative to Hardness of the Machined Surface
Authors: Gessner Andrzej , Staniek Roman , Adam Waldemar 
Published: October 2014

Iron cast machining is nowadays preceded by the process of marking out, ascertaining appropriate casting precision and size of machined surface surpluses. The procedure entails delineating (etching) boundaries of the nominal machining surpluses upon the raw cast surfaces. Their size, standardized according to the ISO 8062 certificate, depends on maximal cast dimensions and the casting method applied. The characteristic machining surplus size of the hereby investigated typical industrial casts ranges between 6 and 8 mm. As casting accuracy is determined by individual foundry standards, the actual machining surplus size values commonly differ from the nominal ones. Thus, in order to ascertain appropriate machining of a given cast, variable surplus distribution is warranted, resulting in actual surplus size values of 2–12 mm.
Inherent to the iron casting procedure are variable hardness values within the casting wall cross-section, with the outer wall surface (directly contingent to the mold that rapidly cools the cast) characterized by the highest hardness value, decreasing incrementally towards its center. Verification of surface hardness values takes place after machining and involves selected work surfaces (e.g. base areas of a runner block). Excessive machining of oversized surpluses within the verified areas results in insufficient hardness of their surfaces.
Bearing the above considerations in mind, optimization of surplus distribution was attempted, relating to most advantageous hardness values of selected cast work surfaces. The investigation was conducted under industrial conditions, upon milling center framework casts. The selected work surfaces were processed gradually; the surface hardness was measured after each machining step. Results thus obtained were implemented for further machining surplus optimization of equivalent casts.
Improvement of the Welding Inspection Process for Projects in the Oil and Gas Industry Using Six Sigma Methodology
Authors: Yousef Muhannad A. , Al-Omairi Khalid , Al-Shehri Abdul-Ilah , Kakpovbia Anthony E. 
Published: October 2014

At the start of welding activities in oil and gas projects, high welding rejection rates (WRR) are often reported. This is a cause for concern to companies because welding defects that are not identified nor corrected can have serious consequences, such as on asset integrity, cost of rework, and schedule impact. Therefore, the quality organizations immediately investigate the different causes and recommend solutions which eventually contributes toward lowering the WRR.
Based on recent field studies conducted in oil and gas projects using the Six Sigma methodology, high WRRs are caused by many factors, including but not limited to the following:
1. New and inexperienced welders with poor welding techniques.
2. Poor environments surrounding the welding activities.
3. Discrepancies and inaccurate data in the welding tracking system (WTS).
These contributing factors can be reduced and eliminated by implementing a strong welding inspection and control program with the following recommendations:
1. Screen for qualified and experienced welders with a proven successful welding history before starting the welding.
2. Test the welders on-site before actual production welding.
3. Implement an encouragement scheme for welders by having frequent toolbox meetings and presenting awards for the best welders according to the lowest rejection rates.
4. Assess the WTS constantly to prevent any inaccurate data.
Oil Stiction in Fast Switching Annular Seat Valves for Digital Displacement Fluid Power Machines
Authors: Roemer Daniel B. , Johansen Per , Pedersen Henrik C. , Andersen Torben O. 
Published: October 2014

Digital Displacement (DD) fluid power machines utilizes electronically controlled seat valves connected to pressure chambers to obtain variable displacement with high operational efficiency and high bandwidth. To achieve high efficiency, fast valve switching is essential and all aspects related to the dynamic behaviour of the seat valves must be considered to optimize the machine efficiency. A significant effect influencing the valves switching performance is the presence of oil stiction when separating the contact surfaces in valve opening movement. This oil stiction force is limited by cavitation for low pressure levels, e.g. valves connected to the low pressure manifold, however for valves operated at higher pressure levels, the oil stiction force is dominating when the separating surfaces are close to contact.
This paper presents an analytic solution to the oil stiction force for annular seat valves suitable for DD applications based on the Reynolds equation and considers contact surface curvature and attack angle. A dynamic cavitation zone is included in the stiction model, and cavitation is found to be present even for seat valves surrounded by high pressure levels.
Virtual Academic Teaching for Next Generation Engineers
Authors: Fortuna Fabio , Bella Gino , Barbuto Mirko , Conti Riccardo , Cozzolino Raffaello , Di Francesco Silvia , Donno Alfredo , Duraccio Vincenzo , Giannini Oliviero , Montesarchio Valeria , Monti Alessio , Tribioli Laura , Trovalusci Federica 
Published: October 2014

Recent advances in web technology have transformed the World-Wide-Web from delivering static text to providing an easily accessible multimedia channel for dynamic, interactive communication. By using such technologies, academic teaching may evolve toward the next-generation way to transfer knowledge. At present time, there are two approaches that can be found: the Massive Open Online Courses (MOOC) approach that delivers video interactive classes to the vast audience with an open-access philosophy and Restrict-Access Courses (RAC) that deliver classes and, more important, standard degrees to limited audience [1]. While the two approaches are comparable when dealing with most academic disciplines, teaching engineering has some peculiarities that let the restricted–access course a more viable solution.
First of all, engineering schools must prepare the student for the profession. In most countries, after the degree there is a professional practice period, thus a closer relation between teacher and students allows bringing the professional knowledge embedded in the academy.
Being also a scientific discipline, engineering takes advantage from a close contact between teaching and research, especially for cutting-edge technologies. Finally, student projects are one of the most important steps of the educational path of the young engineers. Good student projects need one to one supervision, an adequate environment in particular for lab practice, and campuses that only restricted-access academies may provide.
Fuzzy Model for Electrostatic Fluidized Bed Coating
Authors: Trovalusci Federica , Barletta Massimiliano , Giannini Oliviero 
Published: October 2014

The study concerns the coating process of metal substrates in an electrostatic fluidized bed (EFB).
This eco-friendly process is profitably used to coat components of particularly complex shapes. Although this technology is widely spread in several industrial domains, the implementation of appropriate process control procedures is still object of investigation.
A model was generated from experimental data with the aim of predicting, for any set of process parameters, the resulting coating thickness of the sample. With a design of experiment (DOE) approach, the experimental investigation, that is the base for the model, quantifies the coating thickness as a function of the main process parameters namely coating time, applied voltage, and gas flow rate fed into the fluidized bed.
This study addresses the effect of the inherent uncertainties on the predicted coating thickness caused by the approximation in the model parameters. In particular, a fuzzy-logic based approach is used to describe the model uncertainties and the transformation method is used to propagate their effect on the thickness. The fuzzy results are then compared with the data produced by the experimentation leading to the evaluation of the membership level of the dataset to the uncertain model.