Search results for "tractor"

EXPERIMENTAL INVESTIGATION OF DILUTE SOLID-LIQUID SUSPENSION IN AN UNBAFFLED STIRRED VESSELS BY A NOVEL PULSED LASER BASED IMAGE ANALYSIS TECHNIQUE

2009

The availability of experimental information on solid distribution inside stirred tanks is a topic of great importance in several industrial applications. The measurement of solid particle distribution in turbulent multiphase flow is not simple and the development of suitable measurement techniques is still in progress. In this work a novel non-intrusive technique for measuring particle concentration fields in solid-liquid systems is employed. The technique makes use of a laser sheet, a high sensitivity digital camera for image acquisition and a Matlab procedure for post-processing the acquired images. Experimental data are here obtained for the case of an unbaffled stirred tank. Stable tor…

Complex dynamics, hidden attractors and continuous approximation of a fractional-order hyperchaotic PWC system

2018

In this paper, a continuous approximation to studying a class of PWC systems of fractionalorder is presented. Some known results of set-valued analysis and differential inclusions are utilized. The example of a hyperchaotic PWC system of fractional order is analyzed. It is found that without equilibria, the system has hidden attractors.

Localization and dimension estimation of attractors in the Glukhovsky-Dolzhansky system

2016

Alterations in working memory maintenance of fearful face distractors in depressed participants : An ERP study

2023

Task-irrelevant threatening faces (e.g., fearful) are difficult to filter from visual working memory (VWM), but the difficulty in filtering non-threatening negative faces (e.g., sad) is not known. Depressive symptoms could also potentially affect the ability to filter different emotional faces. We tested the filtering of task-irrelevant sad and fearful faces by depressed and control participants performing a color-change detection task. The VWM storage of distractors was indicated by contralateral delay activity, a specific event-related potential index for the number of objects stored in VWM during the maintenance phase. The control group did not store sad face distractors, but they automa…

Minimally Invasive Surgery for Decompression in Chiari I Malformation

2019

Chiari malformations (CMs) includes different pathologies sharing common anatomic deformities of the brainstem and cerebellum. CM type I was originally introduced by Hans Chiari and described as an “elongation of the tonsils and the medial parts of the inferior lobes of the cerebellum into cone-shaped projections which accompany the medulla oblongata into the spinal canal.” The prevalence of CM has been estimated to be between 0.1% and 0.5%, but it is possible that higher rates will be identified since the increasing the use of magnetic resonance imaging (MRI) in common clinical practice. Clinical studies have shown an equal prevalence in both sexes without particular ethnic or geographic d…

Process-Optimized Minimally Invasive Total Hip Replacement via a Direct Anterior Approach with Navigation Control of Leg Length and Offset

2013

The purpose of this study was to analyze a new concept of using the minimally invasive direct anterior approach (DAA) in total hip replacement (THR) in combination with a leg positioner (Rotex-Table) and a modified retractor system (Condor). To control leg length and offset, the navigation system OrthoPilot® (B. Braun, Aesculap) or the Medacta system was used. We retrospectively evaluated the first 100 primary THRs performed with this new concept between 2009 and 2010, regarding the surgical data as well as the radiological and clinical outcome (Hip Disability and Osteoarthritis Outcome score, HOOS). All surgeries were perfomed following a standardized operation technique including navigati…

The use of a new kind of low profile retractor for arteriovenous fistula procedure simplifies and speeds up the intervention

2009

Purpose The aim of this study was to demonstrate the effectiveness of a new kind of disposable surgical retractor in arteriovenous fistula (AVF) procedures in order to achieve an easier, faster and safer surgical intervention. Methods Between January and June 2008, 22 AVF procedures were performed using the 3PAWS ReeTrakttrade; (Insightra Inc. - Irvine, Ca., USA) a self-retaining, low profile retractor. An equivalent patient sample, in which an AVF was performed using conventional retraction devices, was considered for comparison of the intra- and post-operative results. Results In all of the 22 AVF procedures performed, the ReeTrakt™ system has simplified the performance of the surgical te…

Bilateral Iatrogenic Femoral Neuropathy

2015

Dear Editor, Postoperative femoral neuropathy is an uncommon complication associated with pelvic/abdominal surgery. The main mechanism underlying this neuropathy is stretching and/or prolonged compression of the nerve.1,2 The nerve compression can be caused by the self-retaining retractors that are sometimes used during surgery directly constricting the nerve against the pelvic sidewall and inducing ischemia.1 Symptoms of femoral neuropathy are weakness of ipsilateral hip flexion and knee extension, and sensory deficit on the anteromedial thigh. The prognosis is generally good, with partial or complete recovery being common. Postoperative femoral neuropathy is generally unilateral2,3,4; bil…

Interference of Illusory Contour Perception by a Distractor

2021

The visual system is capable of recognizing objects when object information is widely separated in space, as revealed by the Kanizsa-type illusory contours (ICs). Attentional involvement in perception of ICs is an important topic, and the present study examined whether and how the processing of ICs is interfered with by a distractor. Discrimination between thin and short deformations of an illusory circle was investigated in the absence or presence of a central dynamic patch, with difficulty of discrimination varied in three levels (easy, medium, and hard). Reaction time (RT) was significantly shorter in the absence compared to the presence of the distractor in the easy and medium condition…

In vitro comparison of the efficacy of two fractured implant-prosthesis screw extraction methods: Conventional versus mechanical.

2019

Abstract Statement of problem Implant-supported prostheses may be subject to esthetic, biological, or mechanical complications. Protocols for dealing with these mechanical problems are sparse. Purpose The purpose of this in vitro study was to compare the efficacy of a mechanical system for extracting fractured implant-prosthesis screws with the conventional method. Material and methods A total of 60 screws were divided into 2 groups according to their morphology (flat screws with a smooth shaft and threaded apical area and screws with a completely threaded body) and subjected to fatiguing and static load testing until fracture. The specimens were assigned to 3 operators with varying levels …