Time filter

Source Type

Boumerdas, Algeria

Cherifi A.,ETS | Dubois M.,ETS | Gardoni M.,ETS | Tairi A.,UMBB
International Journal on Interactive Design and Manufacturing | Year: 2015

In the context of product innovation, the environmental dimension takes a new dimension and can not be separated from other product requirements which make it competitive. Many tools are available but not widely used by companies. In the present work we have adopted an approach using a qualitative evaluation matrix including parameters related to the ease of use of the product related to the organizational preparation for the appropriation of an eco-design approach, in addition to the standard factors of eco-efficiency. In order to help the designer to make a decision, an adapted TRIZ method is proposed (Téoria Rechénia Izobrétatelskikh Zadatch or theory of inventive problem solving). The applicability of this method is justified by the many contradictions in the choices in a study of the life cycle and can help designers and companies to choose an approach to attain a satisfying level of eco-design for the resources invested in it. An application, based on inventive principles, will be adapted and completed.This matrix can help the designer to reduce the scope of his creative investigations. Verification of the results was made by application to various situations of patents published in eco-design and monitoring of student teams that meet the challenges presented during the competition “24 Hours of innovation.” © 2015, Springer-Verlag France. Source

Hamimid S.,L.G.P.C. UFA SETIF | Guellal M.,L.G.P.C. UFA SETIF | Amroune A.,L.G.P.C. UFA SETIF | Zeraibi N.,UMBB
Fluid Dynamics and Materials Processing | Year: 2012

A two-dimensional rectangular enclosure containing a binary-fluid saturated porous layer of finite thickness placed in the centre of the cavity is considered. Phase change is neglected. Vertical and horizontal solid boundaries are assumed to be isothermal and adiabatic, respectively. A horizontal temperature gradient is imposed, driving convection of buoyancy nature. The Darcy equation, including Brinkman and Forchheimer terms is used to account for viscous and inertia effects in the momentum equation, respectively. The problem is then solved numerically in the framework of a Velocity-Pressure formulation resorting to a finite volume method based on the standard SIMPLER algorithm. The effects of the governing parameters (geometric, hydrodynamic and thermal) on fluid flow and heat transfer are investigated. © 2011 Tech Science Press. Source

Benkaci-Ali N.,UMBB | Benmezai A.,University of Science and Technology Houari Boumediene
Journal of Advanced Research in Dynamical and Control Systems | Year: 2014

We present in this paper new results concerning positive solution for the fourth order four-point weighted p(t)-Laplacian like boundary value problem where ℝ+ = [0,+∞), φ(t,x) = |x|p(t)-2x, α ∈ [0,1[, η γ ∈ (0,1), β ≥ 0, p ∈ C ([0,1], (1,+∞)), f ∈ C ([0,1] × ℝ+, ℝ+), a ∈ C ((0,1), (0,+∞)), and b: (0,1) → ℝ+ is a measurable function such that b(t) ≥ 0 for a.e. t ∈ (0,1) and b is positive in a subset of a positive measure. © 2014 Institute of Advanced Scientific Research. Source

Baddari K.,Laboratory of Physics of the Earth | Frolov A.D.,Russian Academy of Sciences | Tourtchine V.,UMBB | Rahmoune F.,Laboratory LIMOSE
Rock Mechanics and Rock Engineering | Year: 2011

The development of the failure process in complex macrosystems using large rock samples subjected to biaxial compression has been studied by means of electromagnetic radiation (EMR) and acoustic emission (AE). In order to increase the stage of macrofailure development, a special procedure of rock loading was used to reveal regularities of nucleation and evolution of electromagnetic and acoustic structures. The synchronised measurements of EMR and AE allowed the control of the stress-strain state in the rocks and the structural developments of fracturing. Nonhomogeneous distribution of the rock spatial crystalline structure subject to load leads to a mosaic distribution of EMR and AE characteristics. As a result, the crack scale effect may be observed in the EMR and AE structure behaviours. The EMR and AE following the failure at different levels behave differently according to the difference in the scale and type of cracks. Intense high-frequency EMR pulses were recorded during the initial stage of microcrack generation occurring prior to major failure of material. This was not the case for AE. The nucleation and development of the macroscopic progressive failure evolution caused an alternation in energetic and frequencial properties of electromagnetic and acoustic events. It has been detected that the tensile cracks were more efficient than shear cracks in capacity of EMR generation. The analysis of self potentials allowed reaching the maximum of registered anomalous variations in the stage of microcracking interaction. This stage showed an increase in the EMR activity, which implies the nucleation of microcracks in various regions of rock interfaces. The gradual accumulation of these defects led to weakening some parts of the rock along with a disintegration of electric anomalies, increase of AE and a significant fluctuation in the rate ofEMR. When crack concentration attains its critical value, which results in the formation of dangerous macroscopic failure of higher level, AE shows an intense activity as well as anEMRlower frequency. The hierarchical development of rock failure using the ratio of the average crack size and the mean distance between cracks as a statistical concentration criterion is used to control the boundary of the transition from small dispersed cracks accumulation to gradual crack merger and the formation of the main macrofailure. These results could be transferred into larger scale levels to forecast dynamic events in the earth crust. © The Author(s) 2010. Source

Hamimid S.,UMBB | Amroune A.,UMBB
Fluid Dynamics and Materials Processing | Year: 2010

The Navier-Stokes and energy equations are numerically solved to investigate two-dimensional convection (originating from the combined effect of buoyancy and surface tension forces) in a liquid metal subjected to transverse magnetic fields. In particular, a laterally heated horizontal cavity with aspect ratio (height/width) =1 and Pr=0.015 is considered (typically associated with the horizontal Bridgman crystal growth process and commonly used for benchmarking purposes). The effect of a uniform magnetic field with different magnitudes and orientations on the stability of the two distinct convective solution branches (with a single-cell or two-cell pattern) of the steady-state flows is investigated. The effects induced by increasing values of the Rayleigh and Hartmann numbers on the heat transfer rate are also discussed. © 2010 Tech Science Press. Source

Discover hidden collaborations