1,738 research outputs found
First Results from Betatron Matching Monitors Installed in the CERN PSB and SPS
In order to satisfy the tight emittance requirements of LHC, betatron matching monitors, based on multiturn beam profile measurements, have been proposed and installed in the CERN SPS and PSB. The SPS monitor is based on a OTR beam profile acquisition system and was installed two years ago and has since been tested. It helped to uncover a mismatch between PS and SPS. Experience and more results wil l be presented. The PSB monitor is based on a wire SEM and has been installed at the beginning of 1998. The first results presented here are very promising
Results of measured data from atomic force microscope on ring pack performance
Frictional losses of an IC engine include 40-50% contribution due to piston assembly-liner conjunction. Reduction of friction would improve fuel efficiency and decrease harmful emissions. Therefore, it is important to accurately predict the frictional losses due to viscous shear of a thin lubricant film as well as boundary friction, generated by the direct contact of real rough contiguous surfaces. Greenwood and Tripp model is used to evaluate the contribution due to boundary friction. The model requires the determination of pressure coefficient of boundary shear strength of asperities, Ï‚, which is analogous to the asperity coefficient of friction. This should be determined through measurement, using Atomic Force Microscopy (AFM) in Lateral Force Mode (LFM). The value of Ï‚ is dependent on the combination of surface and lubricant as a system. Boundary active lubricant additives adsorb or bond to the surface asperities and affect the value of Ï‚. The value of this coefficient also alters with the evolution of interacting surfaces through the process of wear as well as any degradation of the lubricant. The approach can be used to create a database of such values for different lubricant-surface systems, in particular for piston-liner interactions
Report of the study group on a superconducting proton linac as a PS Injector
A proposal was made at the end of 1996 to use the large inventory of RF hardware available after the decommissioning of LEP-2 for the construction of a 2 GeV Superconducting Proton Linac (SPL) to inject directly into the PS [1.1]. The brightness of the beam in the PS at low energy would double, helping the injector complex to satisfy the requirements of the LHC and benefiting the planned proton physics programme. Additional users could also be accommodated thanks to the capability of the SPL to operate at a much larger duty factor than that required for high-energy physics. Consequently, a small study group has been set up to analyse the major technical aspects of the SPL design as well as the processes of injection and capture in the PS. This report summarises the work done so far, and provides some information about the other possible uses of the SPL beam. The feasibility of such a cascade of accelerators is confirmed, although an in-depth design study is still required before the realistic performance and detailed design of that facility can be announced
Effect of cylinder de-activation on the tribological performance of compression ring conjunction
The paper presents transient thermal-mixed-hydrodynamics of piston compression ring-cylinder liner conjunction for a 4-cylinder 4-stroke gasoline engine during a part of the New European Drive Cycle (NEDC). Analyses are carried out with and without cylinder de-activation (CDA) technology in order to investigate its effect upon the generated tribological conditions. In particular, the effect of CDA upon frictional power loss is studied. The predictions show that overall power losses in the piston-ring cylinder system worsen by as much as 10% because of the increased combustion pressures and liner temperatures in the active cylinders of an engine operating under CDA. This finding shows the down-side of this progressively employed technology, which otherwise is effective in terms of combustion efficiency with additional benefits for operation of catalytic converters. The expounded approach has not hitherto been reported in literature
Applying consumer responsibility principle in evaluating environmental load of carbon emissions
There is a need for a proper indicator in order to assess the environmental impact of international
trade, therefore using the carbon footprint as an indicator can be relevant and useful. The aim of this
study is to show from a methodological perspective how the carbon footprint, combined with input-
output models can be used for analysing the impacts of international trade on the sustainable use
of national resources in a country. The use of the input-output approach has the essential advantage
of being able to track the transformation of goods through the economy. The study examines the environmental
impact of consumption related to international trade, using the consumer responsibility
principle. In this study the use of the carbon footprint and input-output methodology is shown on the
example of the Hungarian consumption and the impact of international trade. Moving from a production-
based approach in climate policy to a consumption-perspective principle and allocation,
would also help to increase the efficiency of emission reduction targets and the evaluation of the
ecological impacts of international trade
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