The role of temperature and frequency on fretting wear of a like-on-like stainless steel contact

The influences of environmental temperature and fretting frequency on the mechanisms and rates of wear in a like-on-like 304 stainless steel contact were examined, and mainly attributed to changes in the mechanical response of the bulk material and to changes in the behaviour of the oxide debris formed in the fretting process. At low temperatures, wear proceeds by continual oxide formation and egress from the contact, whilst at high temperatures, the rate of wear is much reduced, associated with the development of oxide formed into a protective bed within the contact. The temperature at which the change between these two behaviours took place was dependent upon the fretting frequency, with evidence that, at this transition temperature, changes in behaviour can occur as the fretting test proceeds under a fixed set of conditions. An interaction diagram has been developed which provides a coherent framework by which the complex effects of these two parameters can be rationalised in terms of widely accepted physical principles

ALADIN is Required for the Production of Fertile Mouse Oocytes

Asymmetric cell divisions depend on the precise placement of the spindle apparatus. In mammalian oocytes, spindles assemble close to the cell's center, but chromosome segregation takes place at the cell periphery where half of the chromosomes are expelled into small, nondeveloping polar bodies at anaphase. By dividing so asymmetrically, most of the cytoplasmic content within the oocyte is preserved, which is critical for successful fertilization and early development. Recently we determined that the nucleoporin ALADIN participates in spindle assembly in somatic cells, and we have also shown that female mice homozygously null for ALADIN are sterile. In this study we show that this protein is involved in specific meiotic stages, including meiotic resumption, spindle assembly, and spindle positioning. In the absence of ALADIN, polar body extrusion is compromised due to problems in spindle orientation and anchoring at the first meiotic anaphase. ALADIN null oocytes that mature far enough to be fertilized in vitro are unable to support embryonic development beyond the two-cell stage. Overall, we find that ALADIN is critical for oocyte maturation and appears to be far more essential for this process than for somatic cell divisions

Reconstruction du réseau métabolique de la tomate

National audienc

Irreversible lysozyme inactivation and aggregation induced by stirring: kinetic study and aggregates characterisation

International audienc

Modeling of heat transfer in tanks during wine-making fermentation

International audienceTemperature is one of the main factors that affect the fermentation kinetics during wine-making. We developed a thermal model to evaluate the power required to control this temperature. The model includes the changes in physio-chemical properties of the must during fermentation and the refrigeration losses to ambient from the other surface of the tank. The results were discussed considering the impact of variables such as the air speed and the air temperature. We finally validated the thermal model at the pilot scal

Reconstruction du réseau métabolique de la tomate

National audienc

Reconstruction du réseau métabolique de la tomate

National audienc

Identification of functional hubs through metabolic networks

International audienc

Identification of functional hubs through metabolic networks

International audienc