Search results for "22"
showing 10 items of 13984 documents
An Additive Model to Predict the Rheological and Mechanical Properties of Polypropylene Blends Made by Virgin and Reprocessed Components
2021
In this work, an additive model for the prediction of the rheological and mechanical properties of monopolymer blends made by virgin and reprocessed components is proposed. A polypropylene sample has been reprocessed more times in an extruder and monopolymer blends have been prepared by simulating an industrial process. The scraps are exposed to regrinding and are melt reprocessed before mixing with the virgin polymer. The reprocessed polymer is, then, subjected to some thermomechanical degradation. Rheological and mechanical experimental data have been compared with the theoretical predictions. The results obtained showed that the values of this simple additive model are a very good fit fo…
Calibration of mobile manipulators using 2D positional features.
2018
International audience; Robotic manipulators are increasingly being attached to Automatic Ground Vehicles (AGVs) to aid in the efficiency of assembly for manufacturing systems. However, calibrating these mobile manipulators is difficult as the offset between the robotic manipulator and the AGV is often unknown. This paper provides a novel, simple, and low-cost method for calibrating and measuring the performance of mobile manipulators by using data collected from a laser retroreflector that digitally detects the horizontal two-dimensional (2D) position of reflectors on an artifact as well as a navigation system that provides the heading angle and 2D position of the AGV. The method is mathem…
Overview of the Development of Hydraulic Above Knee Prosthesis
2017
This paper presents research and development of hydraulically powered above-knee prosthesis (HAKP) and novel prosthetic foot, in order to enable transfemoral (TF) amputees perform stair ascent and other daily activities in as much as possible natural manner. Functions that need exertion of large forces and moments during locomotion such as walking up stairs and slopes cannot be naturally accomplished by commercially available microprocessor-controlled above-knee (AK) prostheses. Also, such prosthetic devices are expensive and unaffordable for major part of amputee population, so mostly used commercial prostheses are energetically passive devices. Deficiency of passive prosthetic devices is …
GOBERNANZA DEL AGUA Y TERRITORIOS HIDROSOCIALES: DEL ANÁLISIS INSTITUCIONAL A LA ECOLOGÍA POLÍTICA
2018
[ES] En las últimas décadas han surgido diversos enfoques para dar respuesta a los desafíos que plantea la gestión del agua. Este artículo presenta, de manera introductoria, las principales aproximaciones teóricas desde las cuales se está analizando en la actualidad el uso y la gobernanza del agua: las corrientes neoinstitucionalistas, la teoría de los recursos comunes y la perspectiva del empoderamiento que se relaciona con la ecología política. La descripción de estos enfoques sirve para contextualizar las distintas aportaciones que se presentan en este monográfico sobre el estudio de los territorios hidrosociales, cuyos principales resultados se exponen sucintamente.
HACIA LA SOBERANIA ALIMENTARIA, ENTRE LA REORGANIZACION INSTITUCIONAL Y LA INICIATIVA LOCAL. EL PROYECTO COMUNITARIO DE RIEGO DE MARIANO ACOSTA (ECUA…
2018
Ecuador es una de las primeras naciones que ha incorporado en su texto constitucional el concepto de soberanía alimentaria. En su Carta Magna de 2008, el artículo 281 señala que la soberanía alimentaria constituye un objetivo estratégico y una obligación, y el artículo 282 requiere que el Estado prohíba el acaparamiento o la privatización del agua. En este contexto, la gestión y la regulación de los recursos hídricos han generado divergencias entre las autoridades centrales y las comunidades rurales. La aprobación de la Ley de Aguas de 2014 ha avivado estas discrepancias. A través del análisis del proyecto comunitario de Mariano Acosta en la provincia de Imbabura, este artículo cuestiona si…
Creiximent de la població, mortalitat, natalitat i migracions a les comarques de Tarragona (1700-1860)
2018
El sentimiento de superioridad de los jesuitas tras la extinción de la Compañía de Jesús
2020
The open metastable structure of a collapsible sand: fabric and bonding
2015
This paper deals with the compositional and textural characteristics determining open metastable structures in the pleistocenic sand outcropping in the Agrigento district (Sicily). The aim of the study was to individuate the bonding types occurring between grains that could generate matric suction phenomena. The composition and microfabric were characterised by means of granulometry, porosimetry, permeability, optical and ESEM-EDS microscopy, thermogravimetry and XR diffractometry, electric conductivity, and ionic chromatography. The data thus acquired show that the skeleton of the sand is constituted mostly by bioclasts and microfossils, calcite and quartz monocrystalline grains. Moreover,…