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Ammi visnaga is a medicinal and aromatic plant from Mediterranean region which is too often chemically symbolised by Khellin and linalool. The species grows spontaneously in all Moroccan biogeoclimates suggesting its chemical variability. Thus, chemical composition of Ammi visnaga’s Essential Oil (EO) fromMeknes-Tafilalet region (Middle Atlas) was for the first time investigated. EO was obtained through hydrodistillation of fresh umbels and analysed by gas chromatography (GC) and mass spectrometry (MS). Phytochemical study of the species was also performed through precipitation and color reactions. Then, antibacterial power of OE was assessed by disc-diffusion method against six ESBL and non-ESBL clinical bacterial strains.

In mass production of cylinder liners, the industrial honing involves multistage abrasive finishing processes, using at first a coarse abrasive stones, and then progressively finer grades, so that a very structured surface of liner is produced. A useful method in diagnosis of industrial honing is presented. It is based on the use of multiscale surface analysis to study the progress of abrasive wear mechanisms which occurred in honing while it was in operation. Thus, the examination of generated surface components by honing to detect the topographical signatures, and especially, signatures of surface in the right scale, is an important part of quality assessment in cylinder liner production.

A consistent increase in demand for special tools designed to enhance an efficient honing of engine cylinder bores is observed. Metallic Bonded Diamond Stones (Dia-M) are more and more used for their wear resistance and their high tool life. However, the hardness of this Metallic Bond leads to the degradation of the honed surface aspect by the formation of smudgy grooves edges (blechmantel). This torn and folded metal affects the required functional performances of the cylinder bore. In this study, two new diamond coated abrasive stones with Vitrified and Resinoid Bonds (respectively Dia-V and Dia-R) are tested and compared to the Dia-M sticks. The influences of bond material on the honing reliability are studied in terms of honed surface aspect, material removal rate and wear properties. Results reveal that the stiffness and the openness structure of the Resinoid Bond leads to a better trade off between surface aspect and tool life.

Face au rechauffement climatique lie a l’effet de serre, les constructeurs automobiles poursuivent leurs efforts dans la reduction des emissions de CO2 . Le ticket d’entree pour repondre a ces contraintes, tout en reduisant les couts d’investissement, est d’optimiser les technologies de finition des futs de carter cylindres des moteurs. Toutefois, l’acceptation des surfaces issues de ces technologies de finition, notamment le rodage, est pilotee par un controle visuel associe a des criteres empiriques d’etat et aspect de surface. Le but du present travail est de proposer une methodologie objective de caracterisation de la qualite de surface, basee sur une analyse multi-echelle de la texture. Differents criteres de topographie et d’aspect de surface ont ete definis. Ils ont ete appliques pour l’etude de l’impact de la vitesse d’expansion des rodoirs sur les variations de la qualite de surface obtenue. Des essais instrumentes ont ete menes, afin de suivre l’evolution des parametres physiques relatifs au rodage, tels que les energies specifiques requises a chacune des configurations. Cette etude demontre le potentiel de la methode developpee a definir des correlations objectives entre les parametres process et la qualite de surface apres rodage.

In this work, an attempt is made to develop a novel approach based on the concept of process signatures to investigate the correlation of the quality of manufactured surface and the process of its generation which is independent to manufacturing conditions. The process signature is the multiscale modifications of surface topography, which depicts the essential changes of the surface state produced on the original surface after abrasive machining. An advanced signal processing technique, the continuous wavelets transform is used to identify the multiscale transfer function of the process which represents the amount of surface modifications. The applicability of this methodology is demonstrated by several practical examples. It is shown that the signature is strongly influenced by abrasive dispersity and granulometry, process induced modes of deformation. The work demonstrates also that the process signatures respond in a predictable fashion to changes in process variables and combinations of stage.

With the increasing use of ultra-hard abrasives and the introduction of more powerful and rigid machines, honing process is spreading its performances. In industrial honing of cylinder liners for internal combustion engines, the degree of penetration that Metallic Bonded Diamond (MBD) abrasive stones have experienced compared to conventional Vitrified Bonded Silicon Carbide (VBSC) tools is obvious. The long tool life of metal bonded diamond sticks is however balanced by its main role in producing torn and folded metal without cutting-effect finish. To simultaneously reduce folding and remove the stock with improved stone life, an experimental investigation is reported on the process variability in finish honing behavior due to stone inconsistency and nature of its properties. We consider the achievable performances by finish honing of cast iron liners with a new abrasive stone. This superabrasive consists of micro-sized diamond abrasives which are bonded with vitrified bond (VBD). By selection of finer grit abrasive while honing with VBD tool, conditions could be created that gave a cutting-effect finish to the diamond honing and minimized the folding over.

The purpose of this paper is to reach the root mean square (RMS) value of the fluctuating temperature along a jet plane by examining only the impact produced by a laser beam after having traversed the heated jet of air. This model is based on the Einstein–Fokker–Planck–Kolmogorov (EFPK) equation, which helped us to determine the value of the jet diffusion coefficient defined as a proportionality factor between the mean square of the deflection angle fluctuations and the length of the corresponding finite laser beam path. The numerical method of calculation in our work uses the value of the localized diffusion coefficient. This plays an essential role in measuring along the RMS of the temperature fluctuations. The obtained values are compared to the experimental measurements.

Controlling the part’s balance of crankshafts are important issues for automotive manufacturers. Unbalance measurement is usually carried out using high-precision mechanical machines. The main objective of the present work is to replace mechanical measuring systems by a non-contact digitizing system, which permits the acquisition of the crankshaft surface. As the geometry to be measured presents a large variety of shapes and textures with accessibility issues, the definition of the best-suited scanning system related to geometrical and industrial constraints is a major issue. In this direction, the paper deals with the definition of a protocol based on quality indicators associated to the collected data to compare various digitizing systems. Those quality indicators are assessed thanks to simple artifacts measurement according to a specific procedure. The comparison protocol is applied to evaluate three triangulation based digitizing systems: Results allow us to identify well-adapted digitizing systems in relation to crankshaft balancing requirements.

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.Copyright © 2008 by ASME

Multiscale surface topography characterization is mostly suited than standard approaches because it is more adapted to the multi-stage process generation. Wavelet transform represents a power tool to perform the multiscale decomposition of the surface topography in a wide range of wavelength. However, characterization results depend closely on the topography data acquisition instrument (resolution, height accuracy, sensitivity...) and also on the wavelet analysis method (discrete or continuous transform). In particular, the choice of wavelet function can have significant effect on the analysis results. In this paper, we present experimental work on a number of popular wavelets functions with the aim of finding wavelets that exhibit optimal description of honed surface features when continuous wavelet transform is used. We demonstrate that the regularity property of wavelet function has a significant influence on the characterization performances. This comparative study shows also that the Morlet wavelet is the more adapted wavelet basis function for multiscale characterization of honed surfaces using continuous wavelet transform.