Rim-spoke composite flywheels: Stress and vibration analysis

Elementary relations are described to determine the material utilization efficiency of a thin wall rim composite flywheel over other configurations. An algorithm is generated for the automatic selection of the optimum composite material for a given thin rim flywheel environment. Subsequently, the computer program NASTRAN is used to perform a detailed stress and vibration analysis of thin wall cylindrical shell rim spoke, single rim and multirim composite flywheels for a specific application

Bedded Pack Management System Case Study

Agribusiness, Agricultural Finance, Farm Management,

Network Friendly P2P-TV: The Napa-Wine Approach

DEMO Sessio

Active contour approach for accurate quantitative airway analysis

Chronic airway disease causes structural changes in the lungs including peribronchial thickening and airway dilatation. Multi-detector computed tomography (CT) yields detailed near-isotropic images of the lungs, and thus the potential to obtain quantitative measurements of lumen diameter and airway wall thickness. Such measurements would allow standardized assessment, and physicians to diagnose and locate airway abnormalities, adapt treatment, and monitor progress over time. However, due to the sheer number of airways per patient, systematic analysis is infeasible in routine clinical practice without automation. We have developed an automated and real-time method based on active contours to estimate both airway lumen and wall dimensions; the method does not require manual contour initialization but only a starting point on the targeted airway. While the lumen contour segmentation is purely region-based, the estimation of the outer diameter considers the inner wall segmentation as well as local intensity variation, in order anticipate the presence of nearby arteries and exclude them. These properties make the method more robust than the Full-Width Half Maximum (FWHM) approach. Results are demonstrated on a phantom dataset with known dimensions and on a human dataset where the automated measurements are compared against two human operators. The average error on the phantom measurements was 0.10mm and 0.14mm for inner and outer diameters, showing sub-voxel accuracy. Similarly, the mean variation from the average manual measurement was 0.14mm and 0.18mm for inner and outer diameters respectively

Algebraic Geometric Comparison of Probability Distributions

We propose a novel algebraic framework for treating probability distributions represented by their cumulants such as the mean and covariance matrix. As an example, we consider the unsupervised learning problem of finding the subspace on which several probability distributions agree. Instead of minimizing an objective function involving the estimated cumulants, we show that by treating the cumulants as elements of the polynomial ring we can directly solve the problem, at a lower computational cost and with higher accuracy. Moreover, the algebraic viewpoint on probability distributions allows us to invoke the theory of Algebraic Geometry, which we demonstrate in a compact proof for an identifiability criterion

DOTASA revisited : 1H NMR and potentiometric studies of a highly asymmetrical ligand and its lanthanide(III) complexes

Poster apresentado no 8th FIGIPAS Meeting in Inorganic Chemistry, Atenas, Grécia, 6 - 9 Jul. 2005.DOTASA (1,4,7,10-tetraazacyclodo-decane-1-(R,S)-succinic acid-4,7,10-triacetic acid) is a DOTA-like macrocyclic ligand showing a carboxymethyl -CH2COOH substituent moiety at a C carbon of one of the four acetate pendant arms, present as a racemic mixture of R and S configurations.The protonation constants of the ligand were determined by potentiometry, giving values close to DOTA except for the extra pK3 value of 5.35 assigned to protonation of the extra carboxylate group in the succinyl arm. The 1H NMR spectra of DOTASA at different pH values are too complex to allow the determination of its microscopic protonation scheme, due to the presence of multiple isomeric structures in solution. The thermodynamic stability constant of its Gd3+ chelate was determined by a potentiometric method, and the value obtained, log KML = 27.2 (0.2), is higher than for the [Gd(DOTA)(H2O)]- complex. The solution structure of the asymmetrical Ln3+ chelates of DOTASA was studied by 1H NMR spectroscopy, indicating the presence of four isomers, corresponding to the combination of the antiprismatic (M) and twisted antiprismatic (m) helicities of the pendant arms and to the R and S configurations of the substituted pendant arm C atom. The m/M isomer ratio decreases along the lanthanide series, with the m isomer decreasing from 90% at La to about 50% from Eu-Lu. This shows that the expected m isomer population of the Gd3+ complex with DOTASA is higher than for the unsubstituted Gd3+-DOTA (~15%) but lower than for a Gd3+ chelate of a RRRR tetrasubstituted DOTA (~70%). Thus the stabilisation of the m isomer by C monosubstitution at the DOTA acetate pendant arms in [Gd(DOTASA)(H2O)]2- is responsible for its increased water exchange rate and higher relaxivity

The Psychometric Properties of the Hypersexual Behavior Inventory Using a Large-Scale Nonclinical Sample

The conceptualization of hypersexuality has begun to converge as a result of proposed diagnostic criteria. However, its measurement is still diverse. The Hypersexual Behavior Inventory (HBI) is one of the most appropriate scales used to assess hypersexuality, but further examination is needed to test its psychometric properties among different clinical and nonclinical groups, including samples outside of the United States. The aim of the present study was to investigate the reliability and the generalizability of HBI and to determine a cutoff score on a large, diverse, online, nonclinical sample (N = 18,034 participants; females = 6132; 34.0%; M-age = 33.6 years, SDage = 11.1). Confirmatory factor analysis (CFA) and reliability indices provided support for the structure of the HBI and demonstrated excellent reliability. Employing latent profile analysis (LPA), seven classes emerged, but they could not be reliably distinguished by objective sexuality-related characteristics. Moreover, it was not possible to determine an adequate cutoff score, most likely due to the low prevalence rate of hypersexuality in the population. HBI can be reliably used to measure the extent of hypersexual urges, fantasies, and behavior; however, objective indicators and a clinical interview are essential to claim that a given individual may exhibit features of problematic sexual behavior