Search results for "T method"
showing 10 items of 1254 documents
Analisi numerico-sperimentale sull’influenza dell’attrito nella delaminazione in Modo II
2011
Stress distribution of complete-arch implant-supported prostheses reinforced with silica-nylon mesh
2019
Made available in DSpace on 2020-12-12T01:20:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-01-01 Background: This study evaluated the presence of a silica-nylon mesh and two cantilever lengths on the biomechanical behavior of complete-arch implant-supported prostheses. Material and Methods: Twenty-four (24) complete mandibular arch implant-supported prostheses were divided into 4 groups according to the presence of reinforcing mesh (with or without) and the cantilever length (molar-15 mm or premolar-5 mm). The specimens were submitted to strain gauge analysis (30-kgf, 10 s) at different points (molar and premolar). Three-dimensional models were created based on the in vitro spec…
Influence of Hyrax screw position on dental movement and cortical bone : a study of finite elements
2019
Background Rapid maxillary expansion (RME) has effects on the dental and periodontal structures of the parts involved, which vary according to the design and position of the expansion screw. The purpose of the study was to determine the optimal three-dimensional position of the Hyrax screw to obtain precise control of the dental movement and effect on the bone cortex using the finite element method (FEM). Material and methods RME was performed from the patient whom two Cone-Beam computerized tomography scans (CBCT) were obtained: T1 before expansion, and T2 three months after stabilization of RME. The FEM model was designed with T1 and of Hyrax photographs. FEM was obtained by comparing the…
Biomechanical effects of Teuscher activator in hyperdivergent Class II malocclusion treatment : a finite element analysis
2021
Background In orthodontic treatment, the combination of an activator with a headgear is commonly used in treatment of the hyperdivergent Class II malocclusion. However, the distribution of stresses transmitted to the maxilla by these appliances has been little studied. This study aimed to compare the biomechanical effects of stresses transmitted to the maxilla and teeth by a Teuscher activator (TA) for different lines of action of extraoral force, using finite element analysis. Material and Methods A tridimensional finite element model of the maxilla and teeth was created based on the true geometry of a human skull. The (TA) and the face bow were designed in 3D computer-aided design and fix…
Cyclic response of masonry infilled RC frames: Experimental results and simplified modeling
2014
The recent large interest in nonlinear seismic analysis methods, static and dynamic, has required proper strategies of modeling based on reliable, and at the same time easy to use, constitutive laws for the structural elements. Regarding the behavior of framed structures, special attention has to be devoted to infills because of the key role they play in modifying overall stiffness, strength and ductility under seismic excitation. Pointing out the attention on this topic the paper discusses a criteria for modeling the structural behavior of infills based on a macromodeling approach, that is to say on the substitution of infills with diagonal pin jointed struts. Is here shown how multilinear…
two-scale three-dimensional boundary element framework for degradation and failure in polycrystalline materials
2014
A fully three-dimensional two-scale boundary element approach to degradation and failure in polycrystalline materials is proposed. The formulation involves the engineering component level (macroscale) and the material grain scale (micro-scale). The damage-induced local softening at the macroscale is modelled employing an initial stress approach. The microscopic degradation processes are explicitly modelled by associating Representative Volume Elements (RVEs) to relevant points of the macro continuum and employing a three-dimensional grain-boundary formulation to simulate intergranular degradation and failure in the microstructural Voronoi-type morphology through cohesive-frictional contact …
Understanding and Controlling Food Protein Structure and Function in Foods: Perspectives from Experiments and Computer Simulations
2020
The structure and interactions of proteins play a critical role in determining the quality attributes of many foods, beverages, and pharmaceutical products. Incorporating a multiscale understanding of the structure–function relationships of proteins can provide greater insight into, and control of, the relevant processes at play. Combining data from experimental measurements, human sensory panels, and computer simulations through machine learning allows the construction of statistical models relating nanoscale properties of proteins to the physicochemical properties, physiological outcomes, and tastes of foods. This review highlights several examples of advanced computer simulations at mol…
CH of masonry materials via meshless meso-modeling
2014
In the present study a multi-scale computational strategy for the analysis of masonry structures is presented. The structural macroscopic behaviour is obtained making use of the Computational Homogenization (CH) technique based on the solution of the boundary value problem (BVP) of a detailed Unit Cell (UC) chosen at the meso-scale and representative of the heterogeneous material. The smallest UC is composed by a brick and half of its surrounding joints, the former assumed to behave elastically while the latter considered with an elastoplastic softening response. The governing equations at the macroscopic level are formulated in the framework of finite element method while the Meshless Meth…
Simultaneous Determination of Thiamin and Riboflavin in Mushrooms by Liquid Chromatography
2001
A simple, fast, inexpensive, and reliable method useful for the simultaneous, routine determination of thiamin and riboflavin in mushrooms is examined. It uses the extraction procedure, with slight modifications, proposed by the AOAC for the extraction of thiamin and riboflavin, followed by a liquid chromatographic separation on a reversed-phase Spherisorb ODS column with methanol/water as mobile phase gradient. Fluorometric detection is used at the following excitation and emission wavelengths, respectively, 360 and 425 nm in the case of thiamin and 422 and 515 nm for riboflavin. The analytical parameters of linearity, the precision of the method (RSD = 2.45 and 2.51% for thiamin and ribof…
Electrical Conduction in Carbon Nanotubes under Mechanical Deformations
2009
The enormous potential of carbon nanotubes (CNTs) as primary components in electronic devices and NEMS necessitates the understanding and predicting of the effects of mechanical deformation on electron transport in CNTs. In principle, detailed atomic/electronic calculations can provide both the deformed configuration and the resulting electrical transport behavior of the CNT. However, the computational expense of these simulations limits the size of the CNTs that can be studied with this technique and a direct analysis of CNTs of the dimension used in nano-electronic devices, particularly multi-wall CNTs (MWNTs), seems prohibitive at the present. Here a computationally effective mixed finit…