An Approximate Approach to Predict the Degree of Starvation in Ball–Disk Machine Based on the Relative Friction

The effect of longitudinal roughness on the friction in EHL contacts is investigated by means of numerical simulations. In the theoretical model the Eyring equation is used to describe the rheological behavior of the lubricant. First the relative friction variation caused by a single harmonic roughness component is computed as a function of the amplitude and wavelength for a wide range of operating conditions. From the results a curve fit formula is derived for the relative friction variation as a function of the out-of-contact geometry of the waviness and a newly derived parameter characterizing the response of the lubricant to pressure variations. Subsequently, the case of a superposition of two harmonic components is considered. It is shown that for the effect on friction such a combined pattern can be represented by a single equivalent wave. The amplitude and the wavelength of the equivalent wave can be determined from a nonlinear relation in terms of the amplitudes and wavelengths of the individual harmonic components. Finally the approach is applied to the prediction of the effect of a real roughness profile (many components) on the friction. From a comparison of the results with full numerical simulations it appears that the simplified approach is quite accurate.

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Approximate approach for optimization space flights with a low thrust on the basis of sufficient optimality conditions

10.1063/1.4972728 ◽

2017 ◽

Cited By ~ 6

Author(s):

Vadim V. Salmin

Keyword(s):

Optimality Conditions ◽

Sufficient Optimality Conditions ◽

Low Thrust ◽

Approximate Approach ◽

Space Flights

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Le Capital Immatériel : Evaluation Et Importance Cas Des Entreprises Marocaines Cotées En Bourse

European Scientific Journal ESJ ◽

10.19044/esj.2016.v12n10p304 ◽

2016 ◽

Vol 12 (10) ◽

pp. 304

Author(s):

Omar Taouab ◽

Lotfi Benazzou ◽

Aziz Babounia

Keyword(s):

Intellectual Capital ◽

Stock Exchange ◽

Information Age ◽

Intangible Capital ◽

Approximate Approach ◽

Fixed Assets ◽

The Subject

Currently, we live in an economy that has changed considerably since the 1990s. This is the time where the economies have moved from the industrial to the information age. For about a decade, companies have switched to the immaterial economy in addition to the physical value (fixed assets: buildings, workshops, computers, vehicles, etc.) and the cash value (cash, receivables, etc.).There is a gaseous value, which is the intangible capital. This new notable concept is the subject of this research, which is to calculate the intangible capital of a sample of listed Moroccan companies, according to an approximate approach, based on publicly available data on Casablanca Stock Exchange website. The purpose of this research is to answer the following questions: What is intellectual capital? What are the components of intangible capital? And what is the weight of intangible capital in Moroccan companies?

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