Search results for "axial"
showing 10 items of 457 documents
On the mechanical stability and out-of-plane dynamics of a travelling panel submerged in axially flowing ideal fluid : a study into paper production …
2011
Improved calculations of beta decay backgrounds to new physics in liquid xenon detectors
2020
We present high-precision theoretical predictions for the electron energy spectra for the ground-state to ground-state $\beta$ decays of $^{214}$Pb, $^{212}$Pb, and $^{85}$Kr most relevant to the background of liquid xenon dark matter detectors. The effects of nuclear structure on the spectral shapes are taken into account using large-scale shell model calculations. Final spectra also include atomic screening and exchange effects. The impact of nuclear structure effects on the $^{214}$Pb and $^{212}$Pb spectra below $\approx100$ keV, pertinent for several searches for new physics, are found to be comparatively larger than those from the atomic effects alone. We find that the full calculatio…
Implementation of a wireless instrumented sphere for fruit processing
2020
The aim of this study was to implement a wireless instrumented sphere to study the critical points in a citrus packing line by real-time measuring the impacts experienced by fruits. The noncommercial device was based on a MEMS (microelectro-mechanical system) sensor node with a sensing range from ±1 g to ±400 g (g = 9.8 m s-2), a ferroelectric RAM (FRAM) memory, a radio frequency (RF) transmitter, a microcontroller, and a 75 mAh lithium battery. The sensor node was placed inside an appropriate case with a total weight of 100 g to represent a 'Tardivo di Ciaculli' mandarin. An FR receiver allowed real-time transmission of the measured data. Total acceleration values, representing the stresse…
Axial Flux Permanent Magnet Synchronous Generators for Pico Hydropower Application: A Parametrical Study
2022
A pico hydropower plant is an energy harvesting system that allows energy production using the power of the water flowing in small watercourses, and in water distribution network. Axial Flow Flux Permanent Magnet Synchronous Generator (AFPMSG) are particularly suitable for this application, being efficient machines that achieve high power with small dimensions. This paper presents a parametrical study of several configurations and topologies of three-phase and single-phase AFPMSG, for pico hydropower application, to assess the most suitable dimensional characteristics for the most energy production using a safe voltage of 25 V. The AFPMSGs here considered has a simple single stator and roto…
Analytical approach for the problems of dynamics and stability of a moving web
2015
Problems of dynamics and stability of a moving web, modelled as an elastic rod or string, and axially travelling between rollers (supports) at a constant velocity, are studied using analytical approaches. Transverse, longitudinal and torsional vibrations of the moving web are described by a hyperbolic second-order partial differential equation, corresponding to the string and rod models. It is shown that in the framework of a quasi-static eigenvalue analysis, for these models, the critical point cannot be unstable. The critical velocities of one-dimensional webs, and the arising non-trivial solution of free vibrations, are studied analytically. The dynamical analysis is then extended into t…
Efectos de la vibración sobre la actividad del rectus abdominis y sobre la transmisión de aceleraciones durante la realización de un puente frontal. …
2012
Durante las dos ultimas decadas se ha incrementado notablemente la utilizacion de la vibracion como medio complementario de ejercicio fisico. La literatura cientifica muestra distintos efectos positivos, aunque la mayor parte de ensayos se han centrado en el analisis del ejercicio de squat. El objetivo del presente estudio fue analizar la actividad muscular del rectus abdominis y la transmision de la vibracion en el cuerpo humano durante la realizacion de un puente frontal sobre una plataforma vibratoria oscilante vibrando a diferentes frecuencias (5, 16, 20 Hz) y a una amplitud constante (3 mm). Las aceleraciones maximas en la cabeza (ejes X, Y, Z) y la actividad electromiografica media de…
On the limit velocity and buckling phenomena of axially moving orthotropic membranes and plates
2011
In this paper, we consider the static stability problems of axially moving orthotropic membranes and plates. The study is motivated by paper production processes, as paper has a fiber structure which can be described as orthotropic on the macroscopic level. The moving web is modeled as an axially moving orthotropic plate. The original dynamic plate problem is reduced to a two-dimensional spectral problem for static stability analysis, and solved using analytical techniques. As a result, the minimal eigenvalue and the corresponding buckling mode are found. It is observed that the buckling mode has a shape localized in the regions close to the free boundaries. The localization effect is demon…
Ultrasound measurements in bone using an array transducer
2014
Analysis of stability of axially moving orthotropic membranes and plates with a linear non-homogeneous tension profile
2011
Walk the Line. The Surgical Highways to the Craniovertebral Junction in Endoscopic Approaches: A Historical Perspective
2018
Background We compiled a comprehensive literature review on the anatomic and clinical results of endoscopic approaches to the craniocervical junction (CVJ) to better contribute to identify the best strategy. Methods An updated literature review was performed in the PubMed, OVID, and Google Scholar medical databases, using the terms “Craniovertebral junction,” “Transoral approach,” “Transnasal approach,” “Transcervical approach,” “Endoscopic endonasal approach,” “Endoscopic transoral approach,” “Endoscopic transcervical approach.” Clinical series, anatomic studies, and comparative studies were reviewed. Results Pure endonasal and cervical endoscopic approaches still have some disadvantages, …