Search results for "mechanical"
showing 10 items of 5999 documents
An analysis in vivo of intracanal bacterial load before and after chemo-mechanical preparation: A comparative analysis of two irrigants and two activ…
2016
Background: The goals of this randomized double-blind trial were to assess the antimicrobial activity in vivo of Sodium hypochlorite (NaOCl) vs. chlorhexidine gluconate (CHX) used in combination either with EndoActivator® or IRRI S® files in patients with apical periodontitis. Material and Methods: A total of 120 patients with apical periodontitis (in single or multiple root canals) were randomly assigned to the four irrigation protocols outlined below: Group A: 5.25% sodium hypochlorite (NaOCl) + EndoActivator®; Group B: 5.25% NaOCl + IRRI S® files; Group C: 2% chlorhexidine gluconate (CHX) + EndoActivator®; Group D: 2% CHX + IRRI S® files. Paper points were used to collect microbiological…
In response to the article published by Fukaya et al., entitled: “Relationships between the center of pressure and the movements of the ankle and kne…
2017
International audience
Modulation of muscle-tendon interaction in the human triceps surae during an energy dissipation task.
2017
The compliance of elastic elements allows muscles to dissipate energy safely during eccentric contractions. This buffering function is well documented in animal models but our understanding of its mechanism in humans is confined to non-specific tasks, requiring a subsequent acceleration of the body. The present study aimed to examine the behaviour of the human triceps surae muscle-tendon unit (MTU) during a pure energy dissipation task, under two loading conditions. Thirty-nine subjects performed a single-leg landing task, with- and without added mass. Ultrasound measurements were combined with 3D kinematics and kinetics to determine instantaneous length changes of MTUs, muscle fascicles, A…
Investigation on the Possibility of Designing an Educational Dynamic Light Scattering Device for Sizing Particles Suspended in Air
2019
Abstract If a light beam meets a fluid that contains scattering centers randomly distributed in suspension, light is scattered by each of them. If the light source is coherent, the scattered waves will be also coherent, therefore they will interfere. The fluctuations of the far-field interference signal, once recorded and digitized, become a time series that can be later on analyzed to produce the average size of the suspended particles or the size distribution. The technique wears the name of Dynamic Light Scattering. We present the results of our investigation on the possibility of using an educational model, made of low-cost, conventional electronics, for recording the time signal of lig…
Thermokinetic Investigation of the Drying Conditions on Amorphous Calcium Phosphate
2017
The present work investigated dried calcium phosphate powders which still retain an amorphous or poorly crystalline structure under a variety of conditions. In previous studies, freeze-drying was found to be the optimum drying condition. However, several publications, as well as our previous studies, have shown that calcium phosphate amorphous, or a poorly crystalline structure, can retain their structure even if the samples are dried immediately after synthesis up to 200°C. In our study, we used the thermokinetic studies FTIR and XRD and showed that the samples are amorphous, or poorly crystalline, but were unable to answer the questions: Is there a difference between the differently dried…
Numerical Study on the Heading Misalignment and Current Velocity Reduction of a Vessel-Shaped Offshore Fish Farm
2019
Recently, the concept of a vessel-shaped fish farm was proposed for open sea applications. The fish farm comprises a vessel-shaped floater, five fish cages, and a single-point mooring system. Such a system weathervanes, and this feature increases the spread area of fish waste. Still, the downstream cages may experience decreased exchange of water flow when the vessel heading is aligned with the current direction, and fish welfare may be jeopardized. To ameliorate the flow conditions, a dynamic positioning (DP) system may be required, and its power consumption should relate to the heading misalignment. This paper proposes an integrated method for predicting the heading misalignment between t…
Nordic walking influence on biomechanical parameters: a systematic review
2020
INTRODUCTION Nordic walking (NW) as a form of physical activity has been shown to have benefits in various domains, but little is known about the effect of NW on more specific biomechanical parameters. The purpose is to determine the impact of NW on the following parameters: walking speed/distance, muscle activation, spatiotemporal parameters, kinematics and ground reaction force. EVIDENCE ACQUISITION A literature search was carried out in different databases from October 2008 to October 2018. This review was conducted and reported in accordance with the PRISMA statement. Finally, 42 studies with a median PEDro Score of 5.5/10 were included. EVIDENCE SYNTHESIS The included studies reported …
Use of Wood Ash in the Forest and its Effect on the Concentration of Essential and Heavy Metallic Elements in Soil and Blueberries <i>(Vacciniu…
2020
The aim of this research is to evaluate the influence of wood ash as an additive fertilizer to forest soil and growing blueberries (Vaccinium myrtillus L.) in terms of metallic element content. To evaluate the effect of wood ash on the forest ecosystem, was selected two forest areas which was fertilized with a certain amount of wood ash (bottom ash and fly ash). The selected forest areas were divided into two types of sampling plots (fertilized with ash and control). Obtained results showed that in the bottom ash dispersion area the concentration of Ca, K, Ni, Cu is almost twice higher in the fertilized plots than control plots. In the blueberries, metallic element content is similar and do…
A comparative analysis between helicopter and seaplane for passenger transport.
2016
Purpose This study aims to develop a methodology to compare the feasibility of helicopter and seaplane regular transport of passengers towards destinations across a remote regional tourist context, where a lack of road and rail infrastructure make these alternative forms of air transport competitive. Design/methodology/approach The authors use a modal split model identifying the quota of passengers that potentially could utilize these two types of services, determined on the basis of previous studies on air transport demand. A technical analysis regarding transport supply is performed to identify the predominant features that should characterize helicopter/seaplane performances. An optimiza…
On the Objective Evaluation of Motion Cueing in Vehicle Simulations
2021
Motion-based simulators are used for a variety of applications, such as research, education, entertainment and training. In fact, motion cues are required to achieve the highest regulatory certifications in training vehicle simulators. Nonetheless, the reproduction of self-motion cues presents technological and economic limitations that are not present in the generation of audiovisual cues. For this reason, the generated motion does not generally match the expected one. Therefore, it is necessary to define means to assess the suitability/fidelity of the generated motion cues. After more than 50 years of motion-based vehicle simulation, no mechanism has been universally accepted as the stand…