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1. |
Record Nr. |
UNINA9910963582903321 |
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Titolo |
Senegal : communications / / World Trade Press |
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Pubbl/distr/stampa |
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Petaluma, Calif., : World Trade Press, c1993-2010 [2010] |
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ISBN |
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Edizione |
[2nd ed.] |
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Descrizione fisica |
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1 online resource (22 p.) |
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Disciplina |
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Soggetti |
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Communication - Senegal |
Communication and traffic - Senegal |
Telecommunication - Senegal |
Mobile communication systems - Senegal |
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Lingua di pubblicazione |
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Formato |
Materiale a stampa |
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Livello bibliografico |
Monografia |
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Note generali |
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Sommario/riassunto |
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Get all three comprehensive reports bundled into one for a complete media and communications profile of Senegal. An excellent source of practical information, this profile offers an extensive dialing guide with city codes, a listing of ISPs and Internet cafes, profiles of the major media outlets (with contact info!) and more. |
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2. |
Record Nr. |
UNINA9911045225503321 |
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Autore |
Stachowiak Gwidon |
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Titolo |
Engineering Tribology |
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Pubbl/distr/stampa |
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Chantilly : , : Elsevier Science & Technology, , 2025 |
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©2026 |
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ISBN |
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Edizione |
[5th ed.] |
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Descrizione fisica |
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1 online resource (903 pages) |
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Altri autori (Persone) |
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BatchelorA. W (Andrew W.) |
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Disciplina |
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Lingua di pubblicazione |
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Formato |
Materiale a stampa |
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Livello bibliografico |
Monografia |
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Nota di contenuto |
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Cover -- ENGINEERING TRIBOLOGY -- Copyright -- Dedication -- Contents -- Preface -- Acknowledgements -- 1 INTRODUCTION -- 1.1 Background -- 1.2 Meaning of tribology -- Lubrication -- Wear -- 1.3 Cost of friction and wear -- 1.4 Summary -- Revision questions -- References -- 2 PHYSICAL PROPERTIES OF LUBRICANTS -- 2.1 Introduction -- 2.2 Oil viscosity -- Dynamic viscosity -- Kinematic viscosity -- 2.3 Viscosity temperature relationship -- Viscosity-temperature equations -- Viscosity-temperature chart -- 2.4 Viscosity index -- 2.5 Viscosity pressure relationship -- 2.6 Viscosity-shear rate relationship -- Pseudoplastic behavior -- Thixotropic behavior -- 2.7 Viscosity measurements -- Capillary viscometers -- Rotational viscometers -- Rotating cylinder viscometer -- Cone on plate viscometer -- Other viscometers -- 2.8 Viscosity of mixtures -- 2.9 Oil viscosity classification -- SAE viscosity classification -- ISO viscosity classification -- 2.10 Lubricant density and specific gravity -- 2.11 Thermal properties of lubricants -- Specific heat -- Thermal conductivity -- Thermal diffusivity -- 2.12 Temperature characteristics of lubricants -- Pour point and cloud point -- Flash point and fire point -- Volatility and evaporation -- Oxidation stability -- Thermal stability -- 2.13 Other lubricant characteristics -- Surface tension -- Neutralization number -- Carbon residue -- 2.14 Optical properties of lubricants -- Refractive index -- 2.15 Additive compatibility and |
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solubility -- Additive compatibility -- Additive solubility -- 2.16 Electrical properties of lubricants -- 2.17 Lubricant impurities and contaminants -- Water content -- Sulphur content -- Ash content -- Chlorine content -- 2.18 Solubility of gases in oils -- 2.19 Summary -- Revision questions -- References -- 3 LUBRICANTS AND THEIR COMPOSITION -- 3.1 Introduction -- 3.2 Mineral oils. |
Sources of mineral oilsSources of mineral oils -- Manufacture of mineral oils -- Types of mineral oils -- Chemical forms -- Sulphur content -- Viscosity -- 3.3 Synthetic oils -- Manufacturing of synthetic oils -- Hydrocarbon synthetic lubricants -- Polyalphaolefins -- Polyphenyl ethers -- Esters -- Cycloaliphatics -- Polyglycols -- Silicon analogues of hydrocarbons -- Silicones -- Silahydrocarbons -- Organohalogens -- Perfluoropolyethers -- Chlorofluorocarbons -- Chlorotrifluoroethylenes -- Perfluoropolyalkylethers -- Cyclophosphazenes -- 3.4 New developments in synthetic lubricants -- Ionic liquid lubricants -- Mesogenic lubricants -- 3.5 Emulsions and aqueous lubricants -- Manufacturing of emulsions -- Characteristics -- Applications -- Polyelectrolyte lubricants -- 3.6 Greases -- Manufacturing of greases -- Composition -- Base oils -- Thickener -- Additives -- Fillers -- Lubrication mechanism of greases -- Grease characteristics -- Consistency of greases -- Mechanical stability -- Drop point -- Oxidation stability -- Thermal stability -- Evaporation loss -- Grease viscosity characteristics -- Classification of greases -- Grease compatibility -- Degradation of greases -- 3.7 Lubricant additives -- Wear and friction improvers -- Adsorption or boundary additives -- Antiwear additives -- Extreme-pressure additives -- Nanoparticle additives -- Anti-oxidants -- Oil oxidation -- Oxidation inhibitors -- Corrosion control additives -- Contamination control additives -- Viscosity improvers -- Pour point depressants -- Foam inhibitors -- Interference between additives -- 3.8 Summary -- Revision questions -- References -- 4 HYDRODYNAMIC LUBRICATION -- 4.1 Introduction -- 4.2 Reynolds equation -- Simplifying assumptions -- Equilibrium of an element -- Continuity of flow in a column -- Simplifications to the Reynolds equation. |
Unidirectional velocity approximation -- Steady film thickness approximation -- Isoviscous approximation -- Infinitely long bearing approximation -- Narrow bearing approximation -- Bearing parameters predicted from Reynolds equation -- Pressure distribution -- Load capacity -- Friction force -- Coefficient of friction -- Lubricant flow -- Summary -- 4.3 Pad bearings -- Infinite linear pad bearing -- Bearing geometry -- Pressure distribution -- Load capacity -- Friction force -- Coefficient of friction -- Lubricant flow rate -- Infinite Rayleigh step bearing -- Other wedge geometries of infinite pad bearings -- Tapered land wedge -- Parabolic wedge -- Parallel surface bearings -- Spiral groove bearing -- Bearings with surface textures -- Finite pad bearings -- Pivoted pad bearing -- Inlet boundary conditions in pad bearing analysis -- 4.4 Converging-diverging wedges -- Bearing geometry -- Pressure distribution -- Full-Sommerfeld boundary condition -- Half-Sommerfeld boundary condition -- Reynolds boundary condition -- Load capacity -- 4.5 Journal bearings -- Evaluation of the main parameters -- Bearing geometry -- Pressure distribution -- Load capacity -- Friction force -- Coefficient of friction -- Lubricant flow rate -- Practical and operational aspects of journal bearings -- Lubricant supply -- Cavitation -- Journal bearings with movable pads -- Journal bearings incorporating a Rayleigh step -- Oil whirl or lubricant caused vibration -- Rotating load -- Tilted shafts -- Partial bearings -- Elastic deformation of the bearing -- Infinitely long approximation in journal bearings -- 4.6 Thermal effects in bearings |
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-- Heat transfer mechanisms in bearings -- Conduction -- Convection -- Conducted/convected heat ratio -- Isoviscous thermal analysis of bearings -- Iterative method -- Constant flow method. |
Non-isoviscous thermal analysis of bearings with locally varying viscosity -- Multiple regression in bearing analysis -- Bearing inlet temperature and thermal interaction between pads of a Michell bearing -- 4.7 Limits of hydrodynamic lubrication -- 4.8 Hydrodynamic lubrication with non-Newtonian fluids -- Turbulence and hydrodynamic lubrication -- Hydrodynamic lubrication with non-Newtonian lubricants -- Inertia effects in hydrodynamics -- Compressible fluids -- Compressible hydrodynamic lubrication in gas bearings -- 4.9 Reynolds equation for squeeze films -- Pressure distribution -- Load capacity -- Squeeze time -- Cavitation and squeeze films -- Microscopic squeeze film effects between rough sliding surfaces -- 4.10 Porous bearings -- 4.11 Summary -- Revision questions -- References -- 5 COMPUTATIONAL HYDRODYNAMICS -- 5.1 Introduction -- 5.2 Non-dimensionalization of the Reynolds equation -- 5.3 The Vogelpohl parameter -- 5.4 Finite difference equivalent of the Reynolds equation -- Definition of solution domain and boundary conditions -- Calculation of pressure field -- Calculation of dimensionless friction force and friction coefficient -- Numerical solution technique for Vogelpohl equation -- 5.5 Numerical analysis of hydrodynamic lubrication in idealized journal and partial arc bearings -- Example of data from numerical analysis, the effect of shaft misalignment -- 5.6 Numerical analysis of hydrodynamic lubrication in a real bearing -- 5.6.1 Thermohydrodynamic lubrication -- Governing equations and boundary conditions in thermohydrodynamic lubrication -- Governing equations in thermohydrodynamic lubrication for a one-dimensional bearing -- Thermohydrodynamic equations for the finite pad bearing -- Boundary conditions -- Finite difference equations for thermohydrodynamic lubrication. |
Treatment of boundary conditions in thermohydrodynamic lubrication -- Computer program for the analysis of an infinitely long pad bearing in the case of thermohydrodynamic lubrication -- Example of the analysis of an infinitely long pad bearing in the case of thermohydrodynamic lubrication -- 5.6.2 Elastic deformations in a pad bearing -- Computer program for the analysis of an elastically deforming onedimensional pivoted Michell pad bearing -- Effect of elastic deformation of the pad on load capacity and film thickness -- 5.6.3 Cavitation and film reformation in grooved journal bearings -- Computer program for the analysis of grooved 360° journal bearings -- Example of the analysis of a grooved 360° journal bearing -- 5.6.4 Vibrational stability in journal bearings -- Determination of stiffness and damping coefficients -- Computer program for the analysis of vibrational stability in a partial arc journal bearing -- Example of the analysis of vibrational stability in a partial arc journal bearing -- 5.7 Computational evaluation of cavitation effects in hydrodynamic bearings -- 5.8 Summary -- Revision questions -- References -- 6 HYDROSTATIC LUBRICATION -- 6.1 Introduction -- 6.2 Hydrostatic bearing analysis -- Flat circular hydrostatic pad bearing -- Pressure distribution -- Lubricant flow -- Load capacity -- Friction torque -- Friction power loss -- Non-flat circular hydrostatic pad bearings -- Pressure distribution -- Lubricant flow -- Load capacity -- Friction torque -- Friction power loss -- 6.3 Generalized approach to hydrostatic bearing analysis -- Flat circular pad bearings -- Flat square pad bearings -- 6.4 Optimization of hydrostatic bearing design -- Minimization of power -- Low-speed recessed bearings -- High-speed recessed bearings -- Control of lubricant film thickness and bearing |
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stiffness -- Stiffness with constant flow method. |
Stiffness with capillary restrictors. |
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Sommario/riassunto |
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Engineering Tribology, Fifth Edition takes an interdisciplinary approach to key concepts and engineering implications of tribology, bringing together the relevant knowledge needed from different fields to achieve effective analysis and control of friction and wear. |
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3. |
Record Nr. |
UNINA9910974797103321 |
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Titolo |
Design for transport : a user-centred approach to vehicle design and travel / / edited by Mike Tovey |
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Pubbl/distr/stampa |
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London : , : Routledge, , 2012 |
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ISBN |
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1-4094-8460-2 |
1-317-15232-8 |
1-315-57667-8 |
1-317-15231-X |
1-283-70568-0 |
1-4094-3326-9 |
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Descrizione fisica |
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1 online resource (407 p.) |
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Collana |
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Design for Social Responsibility Series |
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Altri autori (Persone) |
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Disciplina |
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Soggetti |
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Motor vehicles - Design and construction - Design and construction |
Transportation engineering - Design |
Urban transportation - Planning |
Human engineering |
Industrial design |
Automobiles - Design and construction - Design and construction |
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Lingua di pubblicazione |
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Formato |
Materiale a stampa |
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Livello bibliografico |
Monografia |
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Note generali |
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First published 2012 by Ashgate Publishing. |
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Nota di bibliografia |
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Includes bibliographical references at the end of each chapters and index. |
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Nota di contenuto |
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Cover; Contents; List of Figures; List of Tables; About the Editor; About the Contributors; Introduction; Section One User Needs and Transport; 1 User-Centred Transport Design and User Needs; 2 User-centred |
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Information Design for the Traveller; Section Two Design and the Transport System; 3 Transport Planning; 4 Transport Interchanges and the Integration Design Challenge; Section Three Transport Design Case Studies; 5 Design for Public Transport; 6 Bicycle Design: Creativity and Innovation; 7 Microcars; 8 The Design and Development of Microcab: A Case Study |
Section Four Transport Design: The Case for the Automobile9 Designer's Role in the Automobile Industry; 10 Integrating Design and Engineering in Developing Vehicles; 11 Designing the Interface; 12 Passports to a Community of Practice; Conclusions: Transport Design in the Future; Index |
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Sommario/riassunto |
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The central premise of Design for Transport is that the designer's role is to approach design for transport from the point of view of the user. People have a collection of wants and needs and a significant proportion of them are to do with their requirements for mobility. Design for Transport shows how creative designers can take a user-focused approach for a wide range of types of transport products and systems. In so doing their starting point is one of creative dissatisfaction with what is currently available, and their specialist capability is in imagining and developing new solutions whic |
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