Căutare 2008 fascicula8 după Data publicării

Afișează articolele 21-35 of 35

    • Vegetal Oils as Lubricating Materials 

      Calomir, Camelia; Ștefănescu, Ioan; Chiriță, George (Universitatea ”Dunărea de Jos” din Galați, 2008)
      The success of vegetal oils is related to their biodegradability and reduced toxicity but a wide use is limited by their insufficient stability in time. Biodegradable oils have ecological advantages, being comparable or ...

    • Seizure of a High-Speed Three-Wave Journal Bearing 

      Buzescu, Daniela; Pascovici, Mircea (Universitatea ”Dunărea de Jos” din Galați, 2008)
      This paper is focused on the geometry and operating parameters of the bearing experimentally studied at NASA Glenn Research Center by F. Dimofte. It presents two simple thermoelastohydrodynamic (TEHD) models for two typical ...

    • Analysis of Gear Quality Criteria and Performance of Curved Face width Spur Gears 

      Andrei, Laurentia; Andrei, Gabriel; Walton, Douglas; Dearn, Karl (Universitatea ”Dunărea de Jos” din Galați, 2008)
      For plastic gears, developments in composites and tooth geometry are essential for their selection in power transmissions. In order to enhance the transmissible power level of the plastic spur gears, an arc-shaped tooth ...

    • Behaviour of a Hydrodynamic Journal Bearing: Torque Measurement During Start-Up 

      Bouyer, Jean; Fillon, Michel (Universitatea ”Dunărea de Jos” din Galați, 2008)
      The start-up friction coefficient in hydrodynamic bearings, used by engineers in the design of bearings, is most often issued from an approximation. Several studies can be found in the literature on this topic but most of ...

    • Hydrodynamic Effects of Texture Geometries on Journal Bearing Surfaces 

      Tala-Ighil, Nacer; Maspeyrot, Patrick; Fillon, Michel; Bounif, Abdelhamid (Universitatea ”Dunărea de Jos” din Galați, 2008)
      Lately, the expanding range of tribological applications to the microscopic levels has revived interest in this field. Actually, little is understood about the subtle effects of variations of a journal bearing’s profile ...

    • Study of Wear Evolution for a Hydraulic Oil Using a Four Ball Tester 

      Spânu, Constantin; Rîpă, Minodora; Ciortan, Sorin (Universitatea ”Dunărea de Jos” din Galați, 2008)
      Time is crucial for the wear of materials. Time of an experiment must be long enough to obtain an observable wear but no so long to make the experiments expensive. For determining anti-wear properties of the hydraulic oils ...

    • Global Method Using Experimental Data for Characterizing the Lubricants Durability 

      Rădulescu, Alexandru; Rădulescu, Irina; Bălan, Corneliu; Petrescu, Florin; Pogrion Popescu, Nicolette Amelie (Universitatea ”Dunărea de Jos” din Galați, 2008)
      The paper presents a global method for characterizing the durability of lubricants, in order to establish the moment of changing, using objectives criteria. Three types of lubricants, for essence and Diesel engine, have ...

    • Experimental Study on Roughness Parameters Variation, During Running – in Period, for a Cylinder-Plane Friction Couple 

      Petrescu, Florin; Davidescu, Anton; Vlase, Monica (2008)
      The studies of various lubrication problems have been recently focused on atypical geometrical and operating conditions (extreme conditions). Among these cases, one can find analyses of HD bearings having surface macroscopic ...

    • Characterizing the Wear Particles of Intervertebral Disc Prosthesis and their Biological Response 

      Crețan Stamate, Monica; Gafițanu, Mihai; Stamate, Ciprian (Universitatea ”Dunărea de Jos” din Galați, 2008)
      Prosthetic debris is the leading factor causing prosthetic loosening and requiring revision surgery. Wear debris is formed over time with any prosthesis. Factors determining disc arthroplasty survivability are similar to ...

    • The Tool to Model through Micro Strain and Micro Cutting 

      Tache, Antonio; Tache, Carmen (Universitatea ”Dunărea de Jos” din Galați, 2008)
      The cutter wear is analised by a single hard fixed particle (inclusion) in brittle material. The shakedown pressure of the inclusion contact is directly proportional to shear field stress of the cutter surface and is ...

    • Industrial Gear Oils from Renegerable Feed Stocks 

      Tănăsescu, Constantin; Petre, Diana; Bogatu, Liana; Antonescu, Niculae Napoleon (Universitatea ”Dunărea de Jos” din Galați, 2008)
      The aim of this research study is to obtain industrial gear oils. The formulation of this type of lubricant is based on vegetable oils or mixtures of vegetable oils with more stable base oils and appropriate additives. The ...

    • The Influence of the Applied Load on the Friction Coefficient of the Sintered Iron-Base Bearings 

      Teișanu, Cristina; Gheorghe, Ștefan; Tudor, Andrei; Ciupitu, Ion (Universitatea ”Dunărea de Jos” din Galați, 2008)
      In the recent years the iron base sintered bearings production was considerable increased at the expense of the copper based ones, due to the low cost and availability of the iron powders as well as the higher strength. ...

    • Influence of the Sliding Speed on the Elastohydrodynamic Regime 

      Seiciu, Petre Lucian (Universitatea ”Dunărea de Jos” din Galați, 2008)
      The study of the elastohydrodynamic (EHD) lubrication regime is characterristic for the heavily loaded gears and can be modeled on a two disk (SAE) rig. It is very important to observe and determine the lubrication regime ...

    • The Effect of Wiberg Angle on the Contact Pressure Pistribution in Natural and Artficial Joint 

      Tudor, Andrei; Parsu, Carmen; Sorina, Opriș (Universitatea ”Dunărea de Jos” din Galați, 2008)
      The analogies and differences between the mechanical joints and the biological ones, in the presence of relative motion, are based on the pressure distribution. The paper analysed a numerical model of the pressure distribution ...

    • Nitrogen Influence on Indentation Fracture Toughness of Stainless Steel Coatings 

      Thompson, Mioara; Palaghian, Liviu (Universitatea ”Dunărea de Jos” din Galați, 2008)
      This paper studies some aspects of coatings fracture theory and the possibility of extending Lawn’s equation from Vickers indenter geometry to the Rockwell one. Indentation tests were performed on stainless steel coatings ...