Search results for "Lubricant"

Impact des conditions d'usinage sur la zone du matériau affectée par le procédé

2007

Colloque avec actes et comité de lecture. Internationale.; International audience; Les procédés d'usinage peuvent créer des contraintes résiduelles à la surface des pièces usinées et ainsi modifier la microstructure et la texture de la matière proche de la surface. De tels changements sont importants pour l'étude du comportement des pièces au cours du temps. Il est alors nécessaire de quantifier les contraintes résiduelles, les composantes de texture et de déterminer la microstructure induite par l'usinage pour comprendre et prédire le comportement des surfaces considérées. Dans cette étude, le matériau cuivre pur a été choisi et considéré comme un "système modèle". En tournage, l'influence…

How Do Different Digital Displays Affect the Ocular Surface?

2020

Digital display use has been accepted as a contributing factor to dry eye disease. Nowadays, plenty of new models of digital displays have been developed, and the differences in their nature and the ways in which they are set and used may contribute to differences in the eye-related problems they cause.This study aimed to analyze the differences in ocular surface, tear film, and visual fatigue parameters after reading on different digital displays, with and without initial instillation of artificial tears.Thirty-one healthy individuals ranging in age from 20 to 26 years (mean ± standard deviation, 21.26 ± 1.73 years) were included in this prospective clinical study. Subjects' ocular surface…

Lipid hydrophobicity, physical state and distribution effects on the properties of emulsion-based edible films

2000

Abstract Addition of lipids to polysaccharide-based films is necessary to improve water vapor barrier properties but it leads to a decrease of mechanical properties. Model emulsified edible films mainly composed of methylcellulose (film-forming substance) and lipid mixtures (moisture barrier) were prepared. The effect of the physicochemical characteristics of the lipid phase (hydrophobicity and physical state) and of its distribution within the methylcellulose-matrix on the mechanical and water vapor barrier film properties was investigated. The nature of the lipid phase had little influence on mechanical properties of emulsified films, but had a substantial effect on the water vapor barrie…

Sperm survival assay for toxicity evaluation in ultrasound gels and vaginal lubricants used in reproductive medicine

2016

Modulating carbohydrate-based hydrogels as viscoelastic lubricant substitute for articular cartilages

2017

Viscosupplementation is a therapeutic approach for osteoarthritis treatment, where the synovial fluid, the natural lubricant of the joints, is replaced by viscoelastic solutions with rheological properties comparable or better than the starting material. This study presents the development of an innovative platform for viscosupplementation, based on the optimization of polysaccharide-based colloidal hydrogel, aiming to reduce on-site enzyme degradation and enhance the possibility of hyaluronic acid substitution with alternative biomaterials. Catanionic vesicles are proposed as physical crosslinker that can guarantee the formation of a 'soft', tunable network, offering a dual-therapeutic app…

Statistical tools and control of internal lubricant content of inhalation grade HPMC capsules during manufacture

2016

The internal lubricant content (ILC) of inhalation grade HPMC capsules is a key factor to ensure good powder release when the patient inhales a medicine from a dry powder inhaler (DPI). Powder release from capsules has been shown to be influenced by the ILC. The characteristics used to measure this are the emitted dose, fine particle fraction and mass median aerodynamic diameter. In addition the ILC level is critical for capsule shell manufacture because it is an essential part of the process that cannot work without it. An experiment has been applied to the manufacture of inhalation capsules with the required ILC. A full factorial model was used to identify the controlling factors and from…

Experimental performance evaluation of a vapour compression refrigerating plant when replacing R22 with alternative refrigerants

2011

Abstract This paper presents the results of an experimental analysis comparing the performance of a vapour compression refrigerating unit operating with R22, and its performance in comparison to a new HFC fluid, substituting the former according to Regulation No 2037/2000. In particular, the plant working efficiency was first tested with R22 and then with three new HFC fluids: R417A, R422A and R422D. The investigation verified that despite the case of substitution and the advantage of being able to continue to use mineral oil as a lubricant in the compressor, the performance with the new tested fluids did not result as efficient as when using R22.

Comparative study of the lubricant performance of Compritol® HD5 ATO and Compritol® 888 ATO: effect of polyethylene glycol behenate on lubricant capa…

2003

The aim of this paper is to study the lubricant capacity of Compritol HD5 ATO, a glyceryl and polyethylene glycol dibehenate, obtained by atomization. This material is compared to Compritol 888 ATO, constituted only by glyceryl dibehenate. First, this study verifies that Compritol HD5 ATO and Compritol 888 ATO present the same granular characteristics and that their mixes with Lactopress present no structural differences. Secondly, in term of compressibility and cohesiveness, the use of Compritol 888 ATO or Compritol HD5 ATO with Lactopress does not involve any significant modification. Finally, the minor difference of lubricant capacity between Compritol HD5 ATO and Compritol 888 ATO has n…

Antimicrobial Lubricant Did Not Reduce Infection Rate in Transrectal Biopsy Patients in a Large Randomized Trial Due to Low Complication Rates

2018

Abstract Background Transrectal prostate biopsy (pbx) is the most frequent outpatient procedure in the urological field. Septic complications are a major health issue. Objective To evaluate complication rates with or without an antimicrobial lubricant. Design, setting, and participants A total of 1000 patients received pbx between 2013 and 2015. Information about complications was collected by a 3-wk questionnaire. Return rate was 73.2% (n = 732). Intervention Randomization for pbx with the instillation of an antimicrobial lubricant (intervention group, n = 385) or the standard lubricant (control group, n = 347) was performed. Outcome measurements and statistical analysis Multivariable anal…

A Numerical Approach to Finite Journal Bearings Lubricated With Ferrofluid

1987

Several cases of cylindrical bearings lubricated with ferrofluid are examined by means of a finite-difference numerical procedure. The subregion of cavitation is determined by imposing mass conservation across the “rupture” and “reformation” boundaries of the complete film. The examined cases refer to bearings confined by sealing rings formed by the lubricant itself, for which there is no need of external supply. In each case the most significant parameters are calculated and it is possible to see that the use of these bearings is favorable when speeds are low, clearances large, and loads light, because in such conditions the magnetic effects are comparable with the pure hydrodynamic ones a…