Search results for "Limiting"
showing 10 items of 219 documents
Ab initio simulations on migration paths of interstitial oxygen in corundum
2016
Abstract Ionizing radiation produces in Al 2 O 3 (corundum) crystals primary Frenkel pairs of complementary defects (in oxygen sublattice these are oxygen vacancies and interstitial oxygen ions, V O − O i ). The interstitial O i atoms begin to migrate above certain temperature and create the dumbbell pairs with regular oxygen atoms (O reg − O i ). We have calculated the optimal dumbbell configurations and optimized further migration paths ( i.e. , O i interstitial can break the bond with one O reg atom and moves towards another, one of four next-neighbor O reg atoms). To simulate all possible O i migration trajectories, we have performed large-scale hybrid DFT-LCAO PBE0 calculations on 2 …
Solar and Atmospheric Four-Neutrino Oscillations
2001
We present an analysis of the neutrino oscillation solutions of the solar and atmospheric neutrino problems in the framework of four-neutrino mixing where a sterile neutrino is added to the three standard ones and the mass spectra presents two separated doublets. Such scenarios allow for simultaneous transitions of solar $\nu_e$, as well as atmospheric $\nu_\mu$, into active and sterile neutrinos controlled by the additional mixing angles $\vartheta_{23}$ and $\vartheta_{24}$, and they contain as limiting cases the pure solar $\nu_e$-active and $\nu_e$-sterile neutrino oscillations, and the pure atmospheric $\nu_\mu\to\nu_s$ and $\nu_\mu\to\nu_\tau$ oscillations, respectively. We evaluate t…
Optimization of continuous elastic perfectly plastic beams
2004
Abstract The optimal design of elastic plastic beams subjected to loads quasi-statically variable within a given domain is studied. A minimum volume formulation and a maximum load multiplier formulation are developed, both expressed on the grounds of a statical as well as of a kinematical approach. The search problems are formulated according to three different limiting criteria acting simultaneously. For each criterion a corresponding selected safety factor is imposed. The Euler–Lagrange equations related to the above described problems are deduced. A special iterative technique devoted to the solution of the above referenced problems is proposed. Some numerical examples conclude the paper.
Supination control increases performance in sideward cutting movements in tennis.
2013
The objective of this study was to explore the effects of tennis shoe characteristics on performance during sideward cutting movements followed by direction changes. Five tennis players (age = 21.5 +/- 0.8 years, mass = 75.2 +/- 2.8 kg, and height = 1.78 +/- 0.05 m) participated in the study and 10 tennis shoes were tested. Several footwear mechanical parameters were analyzed: Shore A hardness, longitudinal and transverse flexibility, midsole height at heel, presence of heel counters, and weight. A force plate was used to measure the kinetic variables, and two video cameras were used to perform a three-dimensional photogrammetric analysis. Results revealed that subject-footwear interaction …
Drawing and extruding: Theoretical and approximate formulas
1969
The problem of drawing of wires and of strips has been treated in several studies; among these the studies of Sachs seem essential. However, the results deduced according to similar theories are not always in accordance with the experimental results: reduction of area or of thickness are in fact usually smaller than those resulting from the theory. This is in dependance of the fact that Sachs has adopted the Limiting Condition of Yielding by v. Mises, according to which the limit values of stress in traction and compression are equal. More recently other AA. (Alberti, Noto La Diega, Bugini), admitting the Limiting Condition of Yielding by A. (or of the Paraboloid of Revolution) of which we …
Modelling anaerobic biomass growth kinetics with a substrate threshold concentration.
2004
Abstract Many bacteria have been observed to stop growing below a certain substrate threshold concentration. In this study, a modification of the Monod kinetics expression has been proposed to take into account this substrate threshold concentration observed in bacterial growth. Besides the threshold concentration no additional parameters have been added to the kinetic expression and so, only the substrate threshold concentration and the half-saturation constant have to be estimated for model calibration purposes. Furthermore, for parameter estimation purposes, practical identifiability of this new function has been studied and the results have been satisfactory. The new model has been appl…
Risk analysis in bioequivalence and biowaiver decisions
2013
This article evaluates the current biowaiver guidance documents published by the FDA, EU and WHO from a risk based perspective. The authors introduce the use of a Failure Mode and Effect Analysis (FMEA) risk calculation tool to show that current regulatory documents implicitly limit the risk for bioinequivalence after granting a biowaiver by reduction of the incidence, improving the detection and limiting the severity of any unforeseen bioinequivalent product. In addition, the authors use the risk calculation to expose yet unexplored options for future extension of comparative in vitro tools for biowaivers.
Effect of O2 control and monitoring on the nutraceutical properties of extra virgin olive oils
2016
Abstract The presence of oxygen during malaxation has key role in improving Extra Virgin Olive Oil (EVOO) quality in terms of volatile and phenolic compounds. The objective of this study was to evaluate the influence of the head space malaxer oxygen concentration on the physicochemical characteristics and nutraceutical properties of EVOO from the Nocellara del Belice olives. The acidic compounds were related to the concentration of the oxygen presented in the machine headspace considering a new software application for the online oxygen management opportunely designed and applicable to all the existing plants. The right timepoint and oxygen concentration of the malaxation process was establ…
Positive Tolman Length in a Lattice Gas with Three-Body Interactions
2011
We present a new method to determine the curvature dependence of the interface tension between coexisting phases in a finite volume from free energies obtained by Monte Carlo simulations. For the example of a lattice gas on a 3D fcc lattice with nearest neighbor three-body interactions, we demonstrate how to calculate the equimolar radius ${R}_{e}$ as well as the radius ${R}_{s}$ of the surface of tension and thus the Tolman length $\ensuremath{\delta}({R}_{s})={R}_{e}\ensuremath{-}{R}_{s}$. Within the physically relevant range of radii, $\ensuremath{\delta}({R}_{s})$ shows a pronounced ${R}_{s}$ dependence, such that the simple Tolman parametrization for the interface tension is refutable.…
The Chandra COSMOS Survey, I: Overview and Point Source Catalog
2009
The Chandra COSMOS Survey (C-COSMOS) is a large, 1.8 Ms, Chandra} program that has imaged the central 0.5 sq.deg of the COSMOS field (centered at 10h, +02deg) with an effective exposure of ~160ksec, and an outer 0.4sq.deg. area with an effective exposure of ~80ksec. The limiting source detection depths are 1.9e-16 erg cm(-2) s(-1) in the Soft (0.5-2 keV) band, 7.3e(-16) erg cm^-2 s^-1 in the Hard (2-10 keV) band, and 5.7e(-16) erg cm(-2) s(-1) in the Full (0.5-10 keV) band. Here we describe the strategy, design and execution of the C-COSMOS survey, and present the catalog of 1761 point sources detected at a probability of being spurious of <2e(-5) (1655 in the Full, 1340 in the Soft, and…