Three dimensional flow structures in journal bearings

This paper was presented at the 2nd Micro and Nano Flows Conference (MNF2009), which was held at Brunel University, West London, UK. The conference was organised by Brunel University and supported by the Institution of Mechanical Engineers, IPEM, the Italian Union of Thermofluid dynamics, the Process Intensification Network, HEXAG - the Heat Exchange Action Group and the Institute of Mathematics and its Applications.In general, the fluid flow in journal bearings can be described by the Navier-Stokes Equations and the conservation of mass. The application of the small gap criterion allows a simplification of these equations yielding the Reynolds Equation, which links the local gap size with the pressure gradient resulting in a powerful tool for the designing process of journal bearings. Typically, the Reynolds Equation is used in EHD-design software based on FE-methods, which is used to compute pressure distributions, forces, deformations and many more parameters needed for the selection of the right bearing geometry. However, there are regions in the journal bearing where the Reynolds Equation must fail, because either the small gap criterion or the Couette flow assumption is violated. There are pockets, grooves and holes, which are necessary to distribute the oil supply across the gap. Moreover, the oil feed represents a cross flow perpendicular to the circumferential main flow. In these regions three dimensional flow structures replace the undisturbed Couette flow, which are strongly affected by vortices, but are non-turbulent due to the Re-scale. This work presents experimental data obtained from a cylinder apparatus with moderate gap sizes, which features independently rotating cylinders and a cross flow through a hole in the sidewall. LDV-measurements of velocity profiles and visualization methods to animate the three dimensional nature of the flow are presented. The experimental data are used to validate 3D-CFD calculations, which are expanded towards smaller gap sizes in the range of typical journal bearings in automotive applications

Antitrust Review of the AT&T/TMobile Transaction

In August 2011, the United States brought a landmark antitrust lawsuit to prevent the merger of two of the nation\u27s four largest mobile wireless telecommunications services providers, AT&T Inc. and T-Mobile USA, Inc. But why are so many elected officials asking the Obama administration to intercede in the Department of Justice\u27s lawsuit to force a settlement? Why are they approving a merger that would likely lead to higher prices, fewer jobs, less innovation, and higher taxes for their constituents? Does it have anything to do with the money they are receiving from AT&T and T-Mobile? This Article examines the recent lobbying efforts in the AT&T/T-Mobile merger. AT&T spent $11.69 million on political lobbying in the first six months of 2011. In addition to hefty campaign contributions, it lobbied lawmakers with$52 steaks and $15 gin-and-cucumber puree cocktails. But lobbyists, as this Article outlines, are not the problem. The problem is the combination of lax campaign finance rules and antitrust law\u27s prevailing legal standard, a flexible fact specific rule of reason

Why More Antitrust Immunity for the Media Is a Bad Idea

The U.S. newspaper industry specifically and traditional media industries generally are in transition. In response to declining audiences and advertising revenue, many traditional media firms have laid off journalists and cut back on news. With their financial difficulties, some traditional media firms have called for greater leniency under the federal antitrust laws. Newspaper owners and journalists have called for greater antitrust immunity for joint advertising, joint fees for readership and accessing content online, and joint reporting. Others have called on the Federal Communications Commission (“FCC”) to loosen further its Cross-Ownership Rules. Some politicians have suggested that the federal antitrust agencies give these traditional media firms “more leeway to merge or consolidate.” The Federal Trade Commission (FTC) in recent hearings inquired as to whether antitrust immunity is necessary for newspapers’ collaboration and under what circumstances, if any, antitrust immunity for certain joint conduct could be justified

Behavioral Antitrust

Competition policy is entering a new age. Interest in competition laws has increased world-wide, and the United States no longer holds a monopoly on antitrust policy. In the aftermath of the financial crisis, the question for competition authorities is whether and to what extent does bounded rationality, self-interest and willpower matter. This article explores how the behavioral economics literature will advance competition policy. With increasing interest in the United States and abroad in the implications of behavioral economics for competition policy, this Article first provides an overview of behavioral economics. It next discusses how the assumption of rational, self-interested profit-maximizers became so embedded in competition policy. The Article then discusses to what extent the behavioral economics literature can inform antitrust policies, and provides several recommendations related to the practical application of behavioral economics to competition policy going forward

Antitrust Review of the AT&T/TMobile Transaction

In August 2011, the United States brought a landmark antitrust lawsuit to prevent the merger of two of the nation\u27s four largest mobile wireless telecommunications services providers, AT&T Inc. and T-Mobile USA, Inc. But why are so many elected officials asking the Obama administration to intercede in the Department of Justice\u27s lawsuit to force a settlement? Why are they approving a merger that would likely lead to higher prices, fewer jobs, less innovation, and higher taxes for their constituents? Does it have anything to do with the money they are receiving from AT&T and T-Mobile? This Article examines the recent lobbying efforts in the AT&T/T-Mobile merger. AT&T spent $11.69 million on political lobbying in the first six months of 2011. In addition to hefty campaign contributions, it lobbied lawmakers with$52 steaks and $15 gin-and-cucumber puree cocktails. But lobbyists, as this Article outlines, are not the problem. The problem is the combination of lax campaign finance rules and antitrust law\u27s prevailing legal standard, a flexible fact specific rule of reason

Evaluation of Visible Diffuse Reflectance Spectroscopy in Liver Tissue: Validation of Tissue Saturations Using Extracorporeal Circulation

Significance: Real-time information about oxygen delivery to the hepatic graft is important to direct care and diagnose vascular compromise in the immediate post-transplant period. Aim: The current study was designed to determine the utility of visible diffuse reflectance spectroscopy (vis-DRS) for measuring liver tissue saturation in vivo. Approach: A custom-built vis-DRS probe was calibrated using phantoms with hemoglobin (Hb) and polystyrene microspheres. Ex vivo (extracorporeal circulation) and in vivo protocols were used in a swine model (n=15) with validation via blood gas analysis. Results: In vivo absorption and scattering measured by vis-DRS with and without biliverdin correction correlated closely between analyses. Lin’s concordance correlation coefficients are 0.991 for μa and 0.959 for μs\u27. Hb measured by blood test and vis-DRS with (R2=0.81) and without (R2=0.85) biliverdin correction were compared. Vis-DRS data obtained from the ex vivo protocol plotted against the PO2 derived from blood gas analysis showed a good fit for a Hill coefficient of 1.67 and P50=34  mmHg (R2=0.81). A conversion formula was developed to account for the systematic deviation, which resulted in a goodness-of-fit (R2=0.76) with the expected oxygen dissociation curve. Conclusions: We show that vis-DRS allows for real-time measurement of liver tissue saturation, an indicator for liver perfusion and oxygen delivery

Targeting the Mitotic Checkpoint to Kill Tumor Cells

One of the most common hallmarks of cancer cells is aneuploidy or an abnormal number of chromosomes. This abnormal chromosome content is a consequence of chromosome missegregation during mitosis, a defect that is seen more frequently in tumor cell divisions as in normal cell divisions. In fact, a large fraction of human tumors display a chromosome instable phenotype, meaning that they very frequently missegregate chromosomes. This can cause variegated aneuploidy within the tumor tissue. It has been argued that this hallmark of cancer could be exploited in anti-cancer therapies. Here we test this hypothesis by inactivation of the mitotic checkpoint through RNAi-mediated depletion of an essential checkpoint component, Mps1. The mitotic checkpoint delays segregation of chromosomes during mitosis until all chromosomes are properly attached to the mitotic spindle. Its inactivation will therefore lead to increased segregation errors. Indeed, we show that this can lead to increased cell death in tumor cells. We demonstrate that increased cell death is associated with a dramatic increase in segregation errors. This suggests that inhibition of the mitotic checkpoint might represent a useful anti-cancer strategy