The preliminary design of bearings for the control system of a high-temperature lithium-cooled nuclear reactor

The design of bearings for the control system of a fast reactor concept is presented. The bearings are required to operate at temperatures up to 2200 F in one of two fluids, lithium or argon. Basic bearing types are the same regardless of the fluid. Crowned cylindrical journals were selected for radially loaded bearings and modified spherical bearings were selected for bearings under combined thrust and radial loads. Graphite and aluminum oxide are the materials selected for the argon atmosphere bearings while cermet compositions (carbides or nitrides bonded with refractory metals) were selected for the lithium lubricated bearings. Mounting of components is by shrink fit or by axial clamping utilizing differential thermal expansion

Aspects of command language portability incorporating a machine-independent filestore concept

A brief summary of job control language development precedes a general discussion of possible improvements in command language practice. The user requirements of a command language are considered with special reference to a machine independent basis. "Primitive" functions are defined from this viewpoint. To meet the proposed objective of portability it is suggested that an appreciation of the user interaction with the computer operating system is necessary. This provides the definition of the user profile model based on the user requirements of a command language. A second model is then developed to represent the structure of the operating system. [Continues.

Auxiliary memory for Apollo guidance computer, volume 1 Final report

Auxiliary core and tape memory for Apollo guidance compute

An Integrated Tool for Loop Calculations: aITALC

aITALC, a new tool for automating loop calculations in high energy physics, is described. The package creates Fortran code for two-fermion scattering processes automatically, starting from the generation and analysis of the Feynman graphs. We describe the modules of the tool, the intercommunication between them and illustrate its use with three examples.Comment: 24 pages, 5 figures, 8 table

Radiation Hard Hybrid Pixel Detectors, and a bbbar Cross Section Measurement at the CMS Experiment

Measurements of heavy flavor quark production at hadron colliders provide a good test of the perturbative quantum chromodynamics (pQCD) theory. It is also essential to have a good understanding of the heavy quark production in the search for new physics. Heavy quarks contribute to backgrounds and signals in measurements of higher mass objects, such as the Higgs boson. A key component to each of these measurements is good vertex resolution. In order to ensure reliable operation of the pixel detector, as well as confidence in the results of analyses utilizing it, it is important to study the effects of the radiation on the detector. In the first part of this dissertation, the design of the CMS silicon pixel detector is described. Emphasis is placed on the effects of the high radiation environment on the detector operation. Measurements of the charge collection efficiency, interpixel capacitance, and other properties of the pixel sensors as a function of the radiation damage are presented. In the second part, a measurement of the inclusive bbbar production cross section using the b → μ D0 X, D0 → K π decay chain with data from the CMS experiment at the LHC is presented. The data were recorded with the CMS experiment at the Large Hadron Collider (CERN) in 2010 using unprescaled single muon triggers corresponding to a total luminosity of 25 pb-1. The differential cross section is measured for pT(μ D0) > 6 GeV/c and |η| 6 GeV/c and |η| +0.28-0.25(sys.) ± 0.17(B) ± 0.23(L) μb

Accelerated artificial neural networks on FPGA for fault detection in automotive systems

Modern vehicles are complex distributed systems with critical real-time electronic controls that have progressively replaced their mechanical/hydraulic counterparts, for performance and cost benefits. The harsh and varying vehicular environment can induce multiple errors in the computational/communication path, with temporary or permanent effects, thus demanding the use of fault-tolerant schemes. Constraints in location, weight, and cost prevent the use of physical redundancy for critical systems in many cases, such as within an internal combustion engine. Alternatively, algorithmic techniques like artificial neural networks (ANNs) can be used to detect errors and apply corrective measures in computation. Though adaptability of ANNs presents advantages for fault-detection and fault-tolerance measures for critical sensors, implementation on automotive grade processors may not serve required hard deadlines and accuracy simultaneously. In this work, we present an ANN-based fault-tolerance system based on hybrid FPGAs and evaluate it using a diesel engine case study. We show that the hybrid platform outperforms an optimised software implementation on an automotive grade ARM Cortex M4 processor in terms of latency and power consumption, also providing better consolidation

A Feynman Diagram Analyser DIANA

A C-program DIANA (DIagram ANAlyser) for the automatic Feynman diagram evaluation is presented. It consists of two parts: the analyzer of diagrams and the interpreter of a special text manipulating language. This language is used to create a source code for analytical or numerical evaluations and to keep the control of the process in general.Comment: 20 pages, latex, 3 eps figure

Investigate and classify various types of computer architecture

Issued as Final report, Project no. G-36-60

Hydrological dynamics and fire history of the last 1300years in western Siberia reconstructed from a high-resolution, ombrotrophic peat archive

International audienceSiberian peatlands provide records of past changes in the continental climate of Eurasia. We analyzed a core from Mukhrino mire in western Siberia to reconstruct environmental change in this region over the last 1300 years. The pollen analysis revealed little variation of local pine-birch forests. A testate amoebae transfer function was used to generate a quantitative water-table reconstruction; pollen, plant macrofossils, and charcoal were analyzed to reconstruct changes in vegetation and fire activity. The study revealed that Mukhrino mire was wet until the Little Ice Age (LIA), when drought was recorded. Dry conditions during the LIA are consistent with other studies from central and eastern Europe, and with the pattern of carbon accumulation across the Northern Hemisphere. A significant increase in fire activity between ca. AD 1975 and 1990 may be associated with the development of the nearby city of Khanty-Mansiysk, as well as with the prevailing positive Arctic Oscillation

Ferroelectric Thin Film Materials Deposition By Physical Vapor Deposition

Thin film is a layer of material that has the thickness that ranging from a few nanometers to a few micrometers and have been used in the fabrication of the MEMS devices. The properties of the thin films are affected by the type of the materials and one of the thin film materials is the ferroelectric thin film material. It is a type of material that exhibits polarization without the presence of the electric field. This ferroelectric thin film material is widely used in the fabrication of microelectromechanical systems (MEMS). There are a few manufacturing methods that can apply to the manufacture of MEMS and one of them is the thin film deposition. In this project, the thin film deposition technique used is the powder-based magnetron sputtering. The powder-based magnetron sputtering is different from the conventional magnetron sputtering because the thin film is deposited from the powder target. The deposited thin films are characterized and the electrical properties of the thin films are investigated. The characterization which involved the microstructural analysis and elemental analysis are carried out for the thin film. Overall, the surface of the thin film is smooth, and some may contain contaminant. The electrical properties of the thin films are investigated through the piezoelectric functional test and temperature coefficient of resistance (TCR) test. The piezoelectric coefficient and TCR are the characteristics that needed to consider when designing MEMS devices. The PZT thin films were undergoing piezoelectric functional test and the results indicated that the thin films exhibited piezoelectric effect. In TCR test, the metal thin film (Sb thin film) shows a positive TCR value whereas the non-metal thin film (MgO thin film) shows negative TCR value. There are also some metal thin films such as Ti thin film and Cr thin film that show negative TCR value and this may be due to the presence of the impurities and defects