Search results for " element"
showing 10 items of 2679 documents
On the Finite Element Modeling of the Lumbar Spine: A Schematic Review
2023
Finite element modelling of the lumbar spine is a challenging problem. Lower back pain is among the most common pathologies in the global populations, owing to which the patient may need to undergo surgery. The latter may differ in nature and complexity because of spinal disease and patient contraindications (i.e., aging). Today, the understanding of spinal column biomechanics may lead to better comprehension of the disease progression as well as to the development of innovative therapeutic strategies. Better insight into the spine’s biomechanics would certainly guarantee an evolution of current device-based treatments. In this setting, the computational approach appears to be a remarkable …
Active biomonitoring (moss-bags) of volcanic emissions on Mt. Etna
2011
Biomonitoring may be defined as the use of organisms and biomaterials (biomonitors) to obtain information on certain characteristics of a particular medium (atmosphere, hydrosphere etc.). In particular, mosses accumulate large amounts of trace metals, making them good bioaccumulators to estimate atmospheric pollution. The moss-bags technique, introduced in the early 1970’, has become very popular. Such active biomonitoring technique is particularly useful in highly polluted areas and has been extensively used in industrial and/or urban areas to examine deposition patterns and to recognize point sources of pollution. The main objective of this study, which represents the first application of…
Drāmas elementu izmantošana jaunāko pusaudžu motivācijas veicināšanai angļu valodas gramatikas apgūšanā
2020
Šis diplomdarbs sniedz teorētisku pamatojumu un piedāvā praktiskus padomus drāmas tehnikas izmantošanai angļu valodas stundās pamatskolā. Uzsvars tika likts uz gramatikas kompetences attīstību. Pētījuma mērķis bija noskaidrot, vai ir iespējama drāmas elementu izmantošana pamatskolas angļu valodas stundās un noskaidrot vai tā attīsta izglītojamo gramatikas kompetenci. Prakses laikā tika veikta izpēte, izmantojot gadījuma pētījumu, kā galveno pētījumu metodi. Darbā tika izmantotas tādas datu vākšanas metodes kā novērojumi, anketas un gala testa analīze. Rezultāti pierādīja, ka drāmas paņēmienus var piemērot nodarbībām ar jaunākiem pusaudžiem, kuri studē angļu valodu, arī tika parādīts, ka tā …
Spēļošanas elementu izmantošana tālmācības vidusskolas skolēnu motivācijā
2020
Maģistra darbs “Spēļošanas elementu izmantošana tālmācības vidusskolas skolēnu motivācijā” ir izstrādāts ar mērķi izpētīt tos spēļošanas elementus, kuru izmantošana tālmācības izglītības procesā stimulētu izglītojamo motivāciju, balstoties uz teorētisko avotu un esošās situācijas izpēti. Maģistra darba aktualitāte ir saistīta ar pasaulē straujo izglītības vides digitalizāciju un mācību procesa papildināšanu ar dažādiem digitālajiem mācību līdzekļiem, mācību tehniskajiem līdzekļi, informācijas tehnoloģijām, mācīšanās platformām utml. Darbā raksturota tālmācība kā perspektīva un mūsdienīga izglītības ieguves forma, tālmācības mācīšanās process un mācīšanās īpatnības, spēļošanas elementu izman…
On time-harmonic Maxwell equations with nonhomogeneous conductivities : Solvability and FE-approximation
1989
The solvability of time-harmonic Maxwell equations in the 3D-case with nonhomogeneous conductivities is considered by adapting Sobolev space technique and variational formulation of the probJem in question. Moreover, a finite element approximation is presented in the 3D·case together with an error estimate in the energy norm. Some remarks are given to the 2D-problem arising from geophysics. peerReviewed
Durability of a 3D woven composite assisted by finite element multi-scale modelling
2012
International audience; The textile composite studied is a 3D woven composite. A unit cell is defined by using microscopic examinations of the microstructure. A multiscale approach assisted by the finite element method is performed in order to estimate the effective properties of the composite and then to access to local stress field. This approach allows the determination of the kind of load to which warp yarns are subjected. Moreover, detailed analysis of damaged model using different configurations of broken yarns are treated. The evolution of the stress concentration coefficient highlight the load transfers due to consecutive yarn breaks.
Indirect chronology method employing rare earth elements to identify Sagunto Castle mortar construction periods
2017
A novel indirect chronology method has been developed to identify Sagunto Castle construction periods. The method is based on the use of inductively coupled plasma mass spectrometry (ICP-MS) to determine rare earth elements (REE) and other trace elements in mortars. Additionally, a no destructive geochemical analysis based on X-ray fluorescence (XRF) was employed for major elements determination. Collected chemical data were processed through Principal Component Analysis (PCA) to highlight any differences among the mortars belonging to different buildings and construction periods. The results show that PCA analysis permits to discriminate construction periods according to mortar sample REE …
Influence of the Screw Positioning on the Stability of Locking Plate for Proximal Tibial Fractures: A Numerical Approach
2020
Tibial fractures are common injuries in people. The proper treatment of these fractures is important in order to recover complete mobility. The aim of this work was to investigate if screw positioning in plates for proximal tibial fractures can affect the stability of the system, and if it can consequently influence the patient healing time. In fact, a more stable construct could allow the reduction of the non-weight-bearing period and consequently speed up the healing process. For that purpose, virtual models of fractured bone/plate assemblies were created, and numerical simulations were performed to evaluate the reaction forces and the maximum value of the contact pressure at the screw/bo…
Numerical experimental analysis of hybrid double lap aluminum-CFRP joints
2015
Abstract Due to their reliability and ease of assembly, both the adhesively bonded and the mechanical joints are commonly used in different fields of modern industrial design and manufacturing, to joint composite materials or composites with metals. As it is well known, adhesively bonded joints are characterized by high stiffness and good fatigue life, although delamination phenomena localized near the free edges may limit their use, especially for applications where corrosive environments and/or moisture can lead to premature failure of the bonding. In these cases, a possible alternative is given by the well-known mechanical joints. On the contrary, these last joints (bolted, riveted) requ…
Ritz Solution for Transient Analysis of Variable-Stiffness Shell Structures
2020
The dynamic response of thin-walled structures is driven by mass and stiffness distribution. As such, variable-stiffness (VS) composites offer opportunities to tune structural dynamic responses. To this extent, efficient analysis tools become increasingly important for structural analysis and design purposes. In this work, an efficient and versatile Ritz method for free vibrations and linear transient analysis of VS doubly curved shell structures is presented. VS shell structures are modeled as an assembly of shell-like domains. The shell kinematics is based on the first-order shear deformation theory, and no further assumption is made on the shallowness or on the thinness of the structure.…