Compressible flow computer program for gas film seals

Computer program, AREAX, calculates properties of compressible fluid flow with friction and area change. Program carries out quasi-one-dimensional flow analysis which is valid for laminar and turbulent flows under both subsonic and choked flow conditions. Program was written to be applied to gas film seals

Design study of shaft face seal with self-acting lift augmentation. 4: Force balance

A method for predicting the operating film thickness of self-acting seals is described. The analysis considers a 16.76-cm mean diameter seal that is typical of large gas turbines for aircraft. Four design points were selected to cover a wide range of operation for advanced engines. This operating range covered sliding speeds of 61 to 153 m/sec, sealed pressures of 45 to 217 N/sq cm abs, and gas temperatures of 311 to 977 K. The force balance analysis revealed that the seal operated without contact over the operating range with gas film thicknesses ranging between 0.00046 to 0.00119 cm, and with gas leakage rates between 0.01 to 0.39 scmm

Implantation temperature effects on the nanoscale optical pattern fabrication in a-SiC:H films by Ga+ focused ion beams

ArticleProceedings of the IX International Conference on Ion Implantation and Other Applications of Ions and Electrons ION 2012, Kazimierz Dolny, Poland, June 25-28, 2012This work is related to a novel approach of providing some new generation ultrastable (> 50 years), ultrahigh density (> 1 Tbit/sq.in.) data storage for archival applications. We used ion-implantation to write nanoscale data into hydrogenated amorphous silicon carbide (a-SiC:H) films. Wide bandgap a-SiC:H samples, Ga+ focused ion beam implanted, have been prepared. A range of samples has been focused ion beam patterned under different implantation conditions, with emphasis on different substrate temperatures (typically from 0°C temperature to around room temperature). Some of the room temperature implanted samples were further annealed at + 250°C in vacuum. The focused ion beam patterned samples were then analysed using near-field techniques, like atomic force microscopy, to define optimum implantation conditions and the resulting consequences for archival data storage applications. The atomic force microscopy analysis of Ga+ focused ion beam implanted a-Si1 - xCx:H samples at room temperature and at 0°C revealed an increase of both the depth and the width of the individual lines within the focused ion beam written patterns at the lower temperature, as a result of an increased ion beam induced sputtering yield, in good agreement with the previous results for the case of Ga+ broad beam implantation in a-Si1-xCx:H and again suggesting that the best conditions for optical data storage for archival storage applications would be using Ga+ ion implantation in a-SiC:H films with an optimal dose at room temperatures. Similarly, the atomic force microscopy results confirm that no advantage is expected to result from post-implantation annealing treatments.This work has been supported by the European Community as an Integrating Activity “Support of Public and Industrial Research using Ion Beam Technology (SPIRIT)” under EC contract No. 227012. The support of EC funded project BG051PO001/3.3.-05.001 for this publication is gratefully acknowledged. The Marie Curie Fellowship for T. Tsvetkova was also supported by the European Community under the contract PIEF-GA-2009-251845. The help of D. Dimova-Malinovska and O. Angelov with the samples preparation and useful discussions is also gratefully acknowledged

Application of the Worldline Path Integral Method to the Calculation of Inverse Mass Expansions

Higher order coefficients of the inverse mass expansion of one-loop effective actions are obtained from a one-dimensional path integral representation. For the case of a massive scalar loop in the background of both a scalar potential and a (non Abelian) gauge field explicit results to $O(T^5)$ in the proper time parameter are presented.Comment: 6 pages, LaTeX. Talk given at 5th International Workshop on Software Engineering and Artificial Intelligence for High Energy and Nuclear Physics (AIHENP96), Lausanne (Switzerland), 2-6 September 199

Flow Equations for U_k and Z_k

By considering the gradient expansion for the wilsonian effective action S_k of a single component scalar field theory truncated to the first two terms, the potential U_k and the kinetic term Z_k, I show that the recent claim that different expansion of the fluctuation determinant give rise to different renormalization group equations for Z_k is incorrect. The correct procedure to derive this equation is presented and the set of coupled differential equations for U_k and Z_k is definitely established.Comment: 5 page

The Intrinsic Dimensionality of Attractiveness: A Study in Face Profiles

The study of human attractiveness with pattern analysis techniques is an emerging research field. One still largely unresolved problem is which are the facial features relevant to attractiveness, how they combine together, and the number of independent parameters required for describing and identifying harmonious faces. In this paper, we present a first study about this problem, applied to face profiles. First, according to several empirical results, we hypothesize the existence of two well separated manifolds of attractive and unattractive face profiles. Then, we analyze with manifold learning techniques their intrinsic dimensionality. Finally, we show that the profile data can be reduced, with various techniques, to the intrinsic dimensions, largely without loosing their ability to discriminate between attractive and unattractive face

Renormalization Group Flow Equations and the Phase Transition in O(N)-models

We derive and solve flow equations for a general O(N)-symmetric effective potential including wavefunction renormalization corrections combined with a heat-kernel regularization. We investigate the model at finite temperature and study the nature of the phase transition in detail. Beta functions, fixed points and critical exponents \beta, \nu, \delta and \eta for various N are independently calculated which allow for a verification of universal scaling relations.Comment: 34 pages, 3 tables, 11 postscript figures, LaTe