scholarly journals The Analysis with Finite Elements of the Elasto-plastic Behaviour of the Spinal Immobilizers - in the Case of Comminutive Fractures

2019 ◽  
Vol 57 (2) ◽  
pp. 253-264
Author(s):  
Bogdan Florin Toma ◽  
Constantin Nanu ◽  
Cezar Popescu ◽  
Razvan Vladimir Socolov ◽  
Vasile-Eduard Rosu ◽  
...  

In this paper it is presented a comparative theoretical study - performed by finite element analysis (FEA), of the tension state that appears at the level of the spine, as well as in the areas adjacent to it, under the following conditions: a) the existence of a comminutive fracture at the level of the vertebra T11; b) of the external immobilization of the body through a Lombax orthesis (LO) or of the internal immobilization of the column by means of a spinal fixator (SF); c) of performing some basic flexion or extension movements. In this study, both flexural force and extension force varied on three levels. The results of the comparative theoretical study were supplemented with the clinical observations obtained from a number of 52 patients who had suffered comminutive fractures in the T11 vertebra and who were treated - by external immobilization, in the Lombax orthesis or were surgically treated - by applying a trapped spinal fixator on the T10-T12 vertebrae. The study had demonstrated that, by immobilizing the body in the Lombax orthesis, following the application of the flexion or extension movement, the mobility of the body is low, the bone fragments move less distances by about 12% against to their displacement under the condition of immobilizing the column by a spinal fixator. Although, in the latter case, the displacements of the bone fragments are greater, the elastic behaviour of the spinal fixator determines the returning of the fragments and of the spine to the initial position as well as the distance between the vertebrae. Clinical investigations on patients treated by external immobilization of the body in the Lombax orthesis show that the values of the local kyphosis angle (LKA) are about 30% lower than the values of the same parameter obtained under the surgical treatment.

Author(s):  
Raida Khalil ◽  
Wajdy J. Al-Awaida ◽  
Hamzeh J. Al-Ameer ◽  
Yazun Jarrar ◽  
Amer Imraish ◽  
...  

Background: Fibromyalgia syndrome (FMS) is a chronic disease characterized by widespread body pain, weakness in certain parts of the body (critical points), low pain tolerance, sleep disturbances, and fatigue. This syndrome is considered rare in Jordan. Objectives: The research aimed to find out the association of the angiotensin converting enzyme, methylenetetrahydrofolate reductase, and vitamin D receptor (ACE, MHFTR, and VDR, respectively) genotypes with FMS among Jordanian patients. Methods: This work included 22 FM patients and 22 healthy individuals of Jordanian Arabic origin. The ACE rs4646994, MTHFR rs1801133, and VDR rs2228570 genotypes were determined using polymerase chain reaction (PCR) followed by restriction fragment length polymorphism. Results: No associations between ACE rs4646994, MTHFR rs1801133, and VDR rs2228570 with the vulnerability of a person for the development of FMS were found. However, we found an association between the ACE rs4646994 genotype and restless leg among FM patients. Conclusion: Based on result from this study, it appears that the ACE rs4646994 genotype is associated with restless leg among FMS patients of Jordanian origin. Further clinical investigations with larger sample sizes are required to confirm these findings and to understand the molecular mechanism of ACE rs4646994 genetic variant in the restless leg syndrome among FM patients.


Author(s):  
Gabriella Garcia Moura ◽  
Célia Regina Rangel Nascimento ◽  
Juliene Madureira Ferreira

AbstractWith a global extent, the pandemic of the new coronavirus and the resulting measures to contain the contagion imposed immediate changes in the routine of people and societies. In view of this historical event, the first part of this theoretical study discussed its relationship with the concept of crisis, while circumscribing human development processes, mobilizing reorganizations in life trajectories. In the second part, the intensification of the use of digital tools to support communication during social isolation was highlighted, particularly reflecting on new interactive arrangements and inter-corporeal experiences. The paper reflects on the proximal processes in the new interactive and contextual configurations through the bioecological theory of human development and, based on concepts of the enactive theory, discusses possible implications of the new perceptual fields and the production of meanings with the repositioning of the body and new modes of engagement. The study highlights that the changes, events, relationships, and effects that we are experiencing (trans)form our forms of sociability and bases of psyche.


2012 ◽  
Vol 490-495 ◽  
pp. 1451-1455
Author(s):  
Guang Yao Zhao ◽  
Yi Feng Zhao ◽  
Chuan Yin Tang ◽  
Zhi Yuan Du

Aimed at SUV-type vehicle, simulation and analysis of pressure resistance experiments on the body of automobile has been presented in the paper, according to the vehicle safety regulations and standards of FMVSS216. A limited SUV vehicle model is created; simulation is obtained with the help of software LS-DYNA, based on the principle of finite element analysis method. Assessment of pressure resistance and safety of the automobile has been presented, from the aspect of the deformation of body, the energy absorption of the vehicle and components, and the pressure on the body, etc. By rational improving of the original design of body structure, the reasonable distribution of pressure absorbability of the body of the SUV-type automobile is achieved. The effect of the overall energy absorption of the body is fully exerted, and then the safety of the driver and the passenger in a rollover accident is improved. Research methods and conclusions of this paper provide useful ways and references to the research of the safety of vehicle rollover and design of rationality of body energy absorption


2021 ◽  
pp. 1-9
Author(s):  
Jie Zhang ◽  
Ping Ye ◽  
Lizheng Zhang ◽  
Hongliu Wu ◽  
Tianxi Chi ◽  
...  

BACKGROUND: The treatment of adolescent patients with distal femoral cancer has always been a concern. The limb-salvage, regarded as a mainstream treatment, had been developed in recent years, but its application in children still remains challenging. This is because it can lead to potential limb-length discrepancy from the continued normal growth of the contralateral lower body. The extendable prosthesis could solve this problem. The principle is that it can artificially control the length of the prosthesis, making it consistent with the length of the side of the lower limbs. However, this prosthesis has some complications. The extendable prosthesis is classified into invasive and minimally invasive, which extends the prosthesis with each operation. OBJECTIVE: We designed a new non-invasive prosthesis that can be extended in the body. Based on the non-invasive and extendable characteristics, we need to verify the supporting performance of this prosthesis. METHODS: We carried out a mechanical testing method and finite element analysis simulation. CONCLUSION: The support performance and non-invasively extension of this prosthesis were verified.


2010 ◽  
Vol 645-648 ◽  
pp. 865-868 ◽  
Author(s):  
Ruggero Anzalone ◽  
Massimo Camarda ◽  
Daniel Alquier ◽  
M. Italia ◽  
Andrea Severino ◽  
...  

The fabrication of SiC MEMS-based sensors requires new processes able to realize microstructures on either bulk material or on the SiC surface. The hetero-epitaxial growth of 3C-SiC on silicon substrates allows one to overcome the traditional limitations of SiC micro-fabrication. In this work a comparison between single crystal and poly crystal 3C-SiC micro-machined structures will be presented. The free-standing structures realized (cantilevers and membrane) are also a suitable method for residual field stress investigation in 3C-SiC films. Measurement of the Raman shift indicates that the mono and poly-crystal 3C-SiC structures release the stress in different ways. Finite element analysis was performed to determine the stress field inside the films and provided a good fit to the experimental data. A comprehensive experimental and theoretical study of 3C-SiC MEMS structures has been performed and is presented.


Behaviour ◽  
2017 ◽  
Vol 154 (7-8) ◽  
pp. 809-834
Author(s):  
Douglas A. Nelson ◽  
Ben M. Nickley ◽  
Angelika Poesel ◽  
H. Lisle Gibbs ◽  
John W. Olesik

Dispersal in birds can have an important influence on the genetic structure of populations by affecting gene flow. In birds that learn their songs, dispersal can affect the ability of male birds to share songs in song dialects and may influence mate attraction. We used Inductively Coupled Plasma Mass Spectrometry (ICP-MS) trace element analysis on the body feathers of birds to assess dispersal among four song dialects. We found that (1) most males had a feather element profile typical of only one dialect location; (2) males singing non-local (‘foreign’) dialects in a focal population often learned their foreign songs outside the dialect; and (3) females often dispersed among dialects. We estimated 5% dispersal per year by yearling males between the site of moulting and breeding. Our estimate is consistent with genetic estimates of widespread gene flow between dialects in this subspecies of the white-crowned sparrow.


1930 ◽  
Vol 26 (9) ◽  
pp. 942-942
Author(s):  
H. Bauer

Abstracts. Venereology and Dermatology. Hugo Bauer (D. Z. Bd. 57, H. 4, 29), aiming to study the secretion of myosalvarsan'a, took under observation 4 syphilitics treated with injections of the drug. Excretion of myosalvarsan'a, as well as its absorption, is similar to 'neo' and sulfoxylsalvarsan'y. Most of the arsenobenzol'a introduced into the body is released within a "short time" after injection; four weeks after the cessation of treatment, the body is freed from the maximum amount of introduced As. The author believes that the clinical observations, on the basis of which it is argued that if certain intervals are observed between courses, the cumulative action of As does not occur, are completely fair. The author gives a detailed technique for determining As in selections and supplies the article with visual tables and curves of his own observations.


The mathematical theory of small elastic deformations has been developed to a high degree of sophistication on certain fundamental assumptions regarding the stress-strain relationships which are obeyed by the materials considered. The relationships taken are, in effect, a generalization of Hooke’s law— ut tensio, sic vis . The justification for these assumptions lies in the widespread agreement of experiment with the predictions of the theory and in the interpretation of the elastic behaviour of the materials in terms of their known structure. The same factors have contributed to our appreciation of the limitations of these assumptions. The principal problems, which the theory seeks to solve, are the determination of the deformation which a body undergoes and the distribution of stresses in it, when certain forces are applied to it, and when certain points of the body are subjected to specified displacements. These problems are always dealt with on the assumption that the generalization of Hooke’s law is obeyed by the material of the body and that the deformation is small, i.e. the change of length, in any linear element in the material, is small compared with the length of the element in the undeformed state. Apart from the fact that the generalization of Hooke’s law is obeyed accurately by a very wide range of materials, under a considerable variety of stress and strain conditions, it has the further advantage that it leads to a mathematically tractable theory.


2006 ◽  
Vol 78 (1) ◽  
pp. viii
Author(s):  
Michael Bickel

Trace elements may have different functions in human and animal metabolism: some are toxic (e.g., Hg), others are essential to maintain good health (e.g., Ca), or they can be essential but also toxic, depending on the concentration in the body or in parts thereof (e.g., Se).The importance of various aspects of trace elements in relation to food is steadily increasing in the perception of the consumer and the respective authorities: food contaminants, essential and toxic elements, bioavailability and speciation, nutritional value and fortified food, reliable measurement of contents, etc. In addition, through the many minor and major food-related incidents during recent years the consumer is becoming more concerned about the quality and safety of food. As a result, research and development efforts in this area have also been increased and/or been redirected.TEF-2 was organized in Brussels 7-8 October 2004 by the Institute of Reference Materials and Measurements of the Joint Research Centre of the European Commission, with the support of the Department of Food Analysis, Institute of Agricultural and Food Biotechnology of the University of Warzaw, Poland and the Centre National de la Recherche Scientifique, France. It was carried through under the auspices of IUPAC.The objectives laid down for the symposium were- presenting state-of-the-art analytical methods for the enforcement of legal limits of trace elements in food;- disseminating new ideas and findings within the scientific community;- providing a forum for the exchange of new knowledge and experience between R&D, authorities, and industry; and- bringing together experts in the field with newcomers.TEF-2 was attended by 93 participants from 60 different institutions in 23 countries. It consisted of 26 lectures and 56 posters, structured according to the following four main topics:- trace elements in the food chain (from the environment to shelf product) including the effects of processing and of legislation- trace element bioavailability-toxicological and nutritional aspects- fortified food and supplementation legislation, manufacturing and labeling, standards- advances in trace element analysis in food matricesIt was emphasized that the field of trace elements in food is a lively research area, which generates interest and involvement from researchers, authorities, and industry, of course triggered and nurtured by the equally high interest of the consumer. A selection of the invited contributions to TEF-2 is presented in the subsequent seven papers in this issue.The importance of scientific exchange in this field was, again, recognized during TEF-2. Therefore, the continuation of this series of conferences was discussed, and the venue for the subsequent TEF-3 was decided. It will be organized by R. Lobinski of CNRS in Pau, France, at the beginning of October 2008.Michael BickelConference Editor


2014 ◽  
Vol 970 ◽  
pp. 177-184 ◽  
Author(s):  
Wen Chiet Cheong ◽  
Heng Keong Kam ◽  
Chan Chin Wang ◽  
Ying Pio Lim

A computational technique of rigid-plastic finite element method by using the Eulerian meshing method was developed to deal with large deformation problem in metal forming by replacing the conventional way of applying complicated remeshing schemes when using the Lagrange’s elements. During metal forming process, a workpiece normally undergoes large deformation and causes severe distortion of elements in finite element analysis. The distorted element may lead to instability in numerical calculation and divergence of non-linear solution in finite element analysis. With Eulerian elements, the initial elements are generated to fix into a specified analytical region with particles implanted as markers to form the body of a workpiece. The particles are allowed to flow between the elements after each deformation step to show the deforming pattern of material. Four types of cold forging and sheet metal clinching were conducted to investigate the effectiveness of the presented method. The proposed method is found to be effective by comparing the results on dimension of the final product, material flow behaviour and punch load versus stroke obtained from simulation and experiment.


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