1,721,093 research outputs found
Precocious scaling in lattice gauge theories
No full textWe propose a method to evaluate numerically and in some cases analytically the two-loop contributions to physical quantities without computing Feynman graphs. Such contributions are negligible for the SU(2) Wilson action, which shows a precocious scaling; on the contrary they are important for other actions (including Manton and heat kernel ones) and account for the observed violations of universality. © 1982
Performance characteristic determination of a roller pump for extracorporeal circulation for different working conditions
No full textA novel method for the simultaneous measurement of temperature and strain using a three wire connection
No full textA novel methodology to simultaneously measure strain and temperature by
means of an electrical resistance strain gauge powered by an ac signal and
connected to a strain indicator by means of thermocouple wires is proposed.
The experimental validation of the viability of this method is conducted by
means of a purely electrical simulation of both strain and temperature
signals, respectively from −2000 to 2000 μm m−1 and −250 to 230 ◦C. The
results obtained showed that strain measurement is affected by an error
always less than ±2 μm m−1 for the whole range of simulated strains, while
the error in temperature evaluation is always less than 0.6 ◦C. The effect of
cross-talk between the two signals was determined to be insignificant
Evaluation of error causes in the measurement of respiratory parameters during controlled ventilation: influence of the breathing circuit
No full textDesign of a novel PWV-Varying Arterial Simulator for biomedical applications: a preliminary study
No full textThe increasing trend of cardiovascular diseases recently led to a growing interest in evaluating methods and systems to diagnose and prevent them. Nowadays, one of the key indexes used to assess the health status of the cardiovascular tree is the Pulse Wave Velocity (PWV) which is strictly related to the mechanical and geometrical characteristics of blood vessels. It is currently measured as the ratio between the distance of two transducers located on the human body and the time the pulse takes to travel along the two chosen sites. Unfortunately, to date, the current measurement devices employed show a limited accuracy in PWV assessment, especially due to distance inaccuracy. The development of arterial simulators could potentially improve the current measurement systems accuracy by means of a better calibration. Despite the fact that many systems have been developed through time, they mainly focus on different aspects regarding the relationship between PWV and meaningful hemodynamic quantities rather than trying to provide a PWV measurement reference to test currently available devices. This results in a lack of information on the design of an in vitro experimental set-up specifically able to vary PWV according to different adjustable mechanical characteristics. In such a context, the present study aims at providing a numerical simulation, based on a previously developed mathematical model, as a next step for the design of a novel experimental set-up, constituted by an elastic tube as aortic surrogate (AS), able to simulate a desired PWV range according to different AS inner and outer pressures conditions
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Comparative evaluation of three image analysis methods for angular displacement measurement in a MEMS microgripper prototype: A preliminary study
Full text linkThe functional characterization of MEMS devices is relevant today since it aims at verifying the behavior of these devices, as well as improving their design. In this regard, this study focused on the functional characterization of a MEMS microgripper prototype suitable in biomedical applications: The measurement of the angular displacement of the microgripper comb-drive is carried out by means of two novel automatic procedures, based on an image analysis method, SURF-based (Angular Displacement Measurement based on Speeded Up Robust Features, ADMSURF) and FFT-based (Angular Displacement Measurement based on Fast Fourier Transform, ADMFFT) method, respectively. Moreover, the measurement results are compared with a Semi-Automatic Method (SAM), to evaluate which of them is the most suitable for the functional characterization of the device. The curve fitting of the outcomes from SAM and ADMSURF, showed a quadratic trend in agreement with the analytical model. Moreover, the ADMSURF measurements below 1° are affected by an uncertainty of about 0.08° for voltages less than 14 V, confirming its suitability for microgripper characterization. It was also evaluated that the ADMFFT is more suitable for measurement of rotations greater than 1° (up to 30°), with a measurement uncertainty of 0.02°, at 95% of confidence level
Improved lattice actions for SU(N) × SU(N) chiral models
No full textA multiparameter family of tree level improved actions for SU(N) × SU(N) 2-d chiral models is proposed and the ratios of the scales Λ are calculated. For N = 2 the mass gap is evaluated by a strong coupling expansion and used to select improved actions with larger scaling region. Moreover the non universal O(g2) corrections are shown to be not negligible even for improved actions. © 1983
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