Traversing probe Patent

Flow meter for measuring stagnation pressure in boundary layer around high speed flight vehicl

Rho GTPases as therapeutic targets in Alzheimer’s disease

The progress we have made in understanding Alzheimer’s disease (AD) pathogenesis has led to the identification of several novel pathways and potential therapeutic targets. Rho GTPases have been implicated as critical components in AD pathogenesis, but their various functions and interactions make understanding their complex signaling challenging to study. Recent advancements in both the field of AD and Rho GTPase drug development provide novel tools for the elucidation of Rho GTPases as a viable target for AD. Herein, we summarize the fluctuating activity of Rho GTPases in various stages of AD pathogenesis and in several in vitro and in vivo AD models. We also review the current pharmacological tools such as NSAIDs, RhoA/ROCK, Rac1, and Cdc42 inhibitors used to target Rho GTPases and their use in AD-related studies. Finally, we summarize the behavioral modifications following Rho GTPase modulation in several AD mouse models. As key regulators of several AD-related signals, Rho GTPases have been studied as targets in AD. However, a consensus has yet to be reached regarding the stage at which targeting Rho GTPases would be the most beneficial. The studies discussed herein emphasize the critical role of Rho GTPases and the benefits of their modulation in AD

THERMAL AGEING EFFECTS ON THICKWALLED LINE PIPE

ABSTRACT Line pipe is often coated prior to installation in order to achieve some protection against the environment. Many of the coatings used today require the pipe to not only be cleaned and degreased, but also to be preheated to a temperature of 200-240°C during application of the coating material. A typical coating thermal cycle involves rapid heating of the pipe using induction coils, application of the coating, and quenching to cool the pipe for handling purposes. It is generally understood that this thermal treatment on UOE line pipe, which can last from a couple to as many as ten minutes, has an effect on the pipe yield and, to a lesser extent, tensile strength. For ultradeepwater offshore applications, where collapse is often the controlling design case, the increase in hoop-compressive yield strength is viewed as desirable because of the corresponding increase in collapse pressure. For onshore applications, however, bending due to differential ground movements can be the primary design consideration. In this case, an increase in tensile yield strength in the longitudinal direction may occur, and may result in a higher Y/T ratio. This increased Y/T can reduce the critical buckling strain of a pipeline designed to this limit state. In this paper, the effects of a coating thermal treatment on X70 grade UOE line pipe material properties are presented with particular attention being paid to the effect on the hoopcompressive and axial tensile yield as well as Y/T ratio. Both coating mill and coupon scale thermal treatment were investigated. Comparison was made between full thickness and round bar axial tensile samples. In addition, the influence of over-ageing or extended duration heating is investigated with respect to its impact on strength and ductility as well as the Charpy impact properties. Results of this study indicate increases between 13 and 16% for hoop-compressive yields while increases in the axial direction were approximately half that magnitude. Y/T ratio increases of around 5% were seen in the axial direction. The over ageing study did not demonstrate any detrimental effect of extended duration thermal treatment on the tested material properties. INTRODUCTION The movement of offshore gas transportation pipelines to deeper and deeper waters has generated new challenges. In order to reach depths greater than 2000 m, even with X70 grade, wall thicknesses of nearly 30 mm are required for 24-inch diameter linepipe. The resulting lay tension requirements on the pipe laying vessel are enormous. For this reason, any ability to reduce the pipe wall thickness and still resist the external pressure at these depths would be quite attractive. One of the unfortunate results of the UOE pipe mamfacturing process is a reduction in the compressive yield strength in the hoop direction. This phenomenon has been well documented and is commonly attributed to the Bauschinger effect [1,2]. The Bauschinger effect occurs when a metal is loaded past its elastic limit followed by loading in the opposite direction. During reverse loading, plastic deformation will begin at a significantly lower stress level. This is the case for UOE pipe where the final step of the manufacturing process is cold expansion in order to reduce ovality. This cold expansion step subjects the pipe to plastic tensile strains of around 1% in the hoop direction [I]. It is well known that the collapse resistance of a pipe under external pressure is mainly affected by the geometric ovality and compressive yield strength in the hoop direction [3]. For this reason, the degradation of the yield strength in the hoop direction from the cold expansion process is quite damaging to the pipes ability to resist external pressure. Collapse pressure can be lowered by as much as 20% in comparison to a similar pipe manufactured with another process [I]. A now well known fact is that low temperature thermal treatment can help to recover the compressive yield strength in the hoop direction therefore increasing the collapse resistanc

OMAE2007-29493 LOCAL BUCKLING ASSESSMENTS FOR THE MEDGAZ PIPELINE

ABSTRACT Medgaz is a consortium of leading international energy companies, with the aim of designing, building and operating an Algerian-European gas pipeline via Spain. The offshore section of this pipeline will be 210 km long, traversing the Mediterranean Sea floor at a maximum depth of 2160 metres. The 24-inch diameter, grade X70 line will provide up to 8 billion cubic metres of natural gas per year, with first gas flow expected in 2009