Distribution of forces on supporting teeth in the midpalatal expander during “Hyrax” screw pre-load

2019 ◽  
Vol 1-2 (93) ◽  
pp. 26-31
Author(s):  
K. Młynarek ◽  
J. Żmudzki
Keyword(s):  
Alveolar Bone ◽  
The Finite Element Method ◽  
Midpalatal Suture ◽  
Displacement Analysis ◽  
A Value ◽  
Molar Teeth ◽  
Reaction Forces ◽  
Analysis Design ◽  
Uniform Expansion ◽  
Practical Implications

Purpose: The aim of the study was to determine forces which are transferred to supporting teeth during the treatment with the midpalatal device with Hyrax screw and to evaluate orthodontic and orthopaedic effects based on displacement analysis. Design/methodology/approach: The finite element method (FEM) was used to simulation the midpalatal expansion forces activated by the screw pre-loaded during a turn of 180° which corresponds to daily recommended value. Distribution of expansion forces of Hyrax device was calculated as reaction forces on elastic supports with stiffness corresponding to the teeth working on periodontal ligament in alveolar bone. Findings: On the basis of the displacement analysis was observed the movement of supporting teeth by a value higher than 0.1 mm which corresponds to the recommended daily value. The midpalatal suture splitting forces were determined on the first premolars with a value of 32.8 N and on the first premolars of 44.2 N. Research limitations/implications: The studies did not take into account the shape of palate other craniofacial bones and their stiffness. Practical implications: Adjusting the stiffness of the device to degree of ossification midpalatal suture and teeth mobility. Searching for new solutions which eliminate the negative phenomenon of tilting teeth during the expansion of maxilla and recommending a surgically assisted techniques. Originality/value: The simulation confirmed that treatment with Hyrax screw gives a uniform expansion with values of forces corresponded to stiffness of premolar and molar teeth. The studies have indicated a possibility of tendency to tilting the supporting teeth what is a negative phenomenon.

Stress Variation in the Orthodontic Tipping Phenomenon Analysis through the finite element method

2018 ◽  
Vol 69 (8) ◽  
pp. 1992-1995
Author(s):  
Dan Dragos Sita ◽  
Ligia Brezeanu ◽  
Cristina Bica ◽  
Dana Manuc ◽  
Edwin Sever Bechir ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Alveolar Bone ◽  
Complex Structure ◽  
External Action ◽  
The Finite Element Method ◽  
Stress Variation ◽  
Orthodontic Bracket ◽  
Method Analysis ◽  
Element Method

The purpose of the study is to assess through a FEM (Finite Element Method analysis), the behavior of a complex structure (enamel-tooth-alveolar bone-periodontal ligament-pulp), subjected to an external load through an orthodontic bracket-with forces of various intensities and to determine its influence on the entire structure.It is necessary to analyze the way all elements of the structure take over the external action given by the action of an orthodontic appliance through the brackets and the influence on the inner component -the pulp-inside of which there are the nerve endings.

An Analysis of Conventional and Self-Aligned four Terminal Resistor Structures for The Determination of The Contact Resistivity from End Resistance Measurements

1986 ◽  
Vol 71 ◽  
Author(s):  
I. Suni ◽  
M. Finetti ◽  
K. Grahn
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Computer Model ◽  
Contact Resistivity ◽  
Experimental Results ◽  
The Finite Element Method ◽  
Model Based ◽  
A Value ◽  
And Diffusion

AbstractA computer model based on the finite element method has been applied to evaluate the effect of the parasitic area between contact and diffusion edges on end resistance measurements in four terminal Kelvin resistor structures. The model is then applied to Al/Ti/n+ Si contacts and a value of contact resistivity of Qc = 1.8×10−7.Ωcm2 is derived. For comparison, the use of a self-aligned structure to avoid parasitic effects is presented and the first experimental results obtained on Al/Ti/n+Si and Al/CoSi2/n+Si contacts are shown and discussed.

Frequency dependent resistance calculation of multiple conductors

2017 ◽  
Vol 36 (5) ◽  
pp. 1396-1410
Author(s):  
Tomislav Župan ◽  
Bojan Trkulja
Keyword(s):  
Design Methodology ◽  
Numerical Approach ◽  
Effective Resistance ◽  
Proximity Effects ◽  
The Finite Element Method ◽  
Frequency Range ◽  
Frequency Dependent ◽  
Content Type ◽  
Electromagnetic Devices ◽  
Practical Implications

Purpose The purpose of this paper is to present a method for calculating frequency-dependent resistance when multiple current-carrying conductors are present. Design/methodology/approach Analytical and numerical formulations are presented. Both skin- and proximity-effects are considered in the numerical approach, whereas only skin-effect can be taken into account in analytical equations. The calculation is done using a self-developed integral equation-based field solver. The results are benchmarked using professional software based on the finite element method (FEM). Findings Results from the numerical approach are in agreement with FEM-based software throughout the whole frequency range. Analytical formulations yield unsatisfactory results in higher frequency range. When multiple conductors are mutually relatively close, the proximity-effect has an impact on effective resistance and has to be taken into account. Research limitations/implications The methodology is presented using axially symmetrical conductors. However, the same procedure can be developed for straight conductors as well. Practical implications Presented fast and stable procedure can be used in most electromagnetic devices when frequency-dependent resistance needs to be precisely determined. Originality/value The value of the presented numerical methodology lies in its ability to take both skin- and proximity-effects into account. As conductors are densely packed in most electromagnetic devices, both effects influence the effective resistance. The method can be easily implemented using a self-developed solver and yields satisfactory results.

scholarly journals Cone-Beam Computed Tomography Evaluation of Alveolar Bone Dehiscences on Mesiobuccal Root Region of Upper First Molar Teeth

2020 ◽  
Vol 26 (2) ◽  
pp. 195-200
Author(s):  
Gamze NALCI ◽  
Tayfun ALAÇAM ◽  
Elshad SALMANOV ◽  
Muhsin Said KARATAŞ ◽  
Cemile Özlem ÜÇOK
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Alveolar Bone ◽  
Cone Beam ◽  
Root Region ◽  
Molar Teeth

Weak Ties and Value of a Network in the New Internet Economy

2017 ◽  
pp. 66-84 ◽  
Author(s):  
Davide Di Fatta ◽  
Roberto Musotto ◽  
Vittorio D'Aleo ◽  
Walter Vesperi ◽  
Giacomo Morabito ◽  
...  
Keyword(s):  
Social Media ◽  
Social Network ◽  
Virtual Network ◽  
The Internet ◽  
Rapid Rise ◽  
A Value ◽  
Internet Economy ◽  
The Relationship ◽  
Practical Implications ◽  
Scholarly Attention

The rapid rise in internet economy is reflected in increased scholarly attention on the topic, with researchers increasingly exploring the marketing approaches and strategies now available through social media. The network provides a value for companies, thus becomes essential acquire greater awareness to evaluate and quantify its value. What are practical implications for managers? Social network analysis is nowadays an essential tool for researchers: the aim of this chapter is to extend the internet economy research to network theories. Today, there are emerging observations on the global internet economy, but there is a big gap in literature indeed. At first, literature focused on people. Now, on digitalized information. Firms are connected in a virtual network and there are undefined distances in terms of space and time. Traditional methods of analysis are no more efficient: to analyze the relationship in the network society, we need a different paradigm to approach network issue.

The generative role of curiosity in soft skills development for contemporary VUCA environments

2020 ◽  
Vol 33 (5) ◽  
pp. 737-751
Author(s):  
Alison Horstmeyer
Keyword(s):  
Design Methodology ◽  
Soft Skills ◽  
The Body ◽  
Skills Development ◽  
Soft Skill ◽  
Content Type ◽  
A Value ◽  
Skill Gaps ◽  
Practical Implications

PurposeThis paper examines the role of curiosity in volatile, uncertain, complex and ambiguous (VUCA) work contexts.Design/methodology/approachThis conceptual article relied upon an examination of literature about curiosity, VUCA and soft skills.FindingsCuriosity, when encouraged and supported within the workforce, may aid organizations in closing soft skill gaps and better navigating ambiguity, perpetually changing business landscapes, and rapidly advancing technology.Research limitations/implicationsEmpirical research is needed to validate, confirm and further explicate the specific mechanisms and value of curiosity within VUCA environments.Practical implicationsOrganizations need to move beyond espousing a value of curiosity to deliberately and effectively cultivating and supporting it within their employees.Originality/valueAlthough ample research and literature has examined curiosity, soft skills and VUCA environments independently, the body of literature on the specific role of curiosity in such environments is limited.

Influence of scarcity claims on product evaluation: The role of reversibility of decision

2018 ◽  
Vol 46 (2) ◽  
pp. 281-292 ◽  
Author(s):  
Seung Yun Lee ◽  
Sangdo Oh ◽  
Sunho Jung
Keyword(s):  
Product Evaluation ◽  
Inference Process ◽  
A Value ◽  
Product Value ◽  
Manipulative Intent ◽  
Positive Effect ◽  
Practical Implications

Marketers often employ scarcity messages to attract consumers. In this study, we showed that consumers make inferences about the truth or falsity of scarcity claims. When consumers interpret scarcity as a value signal, scarcity will positively influence product evaluation. In contrast, when scarcity is interpreted as a signal with manipulative intent, the positive effect of scarcity on product evaluation is reduced. Accordingly, we identified reversibility of decision as a moderating factor in the positive effect of scarcity on product evaluation. Results showed that scarcity had a positive effect on product evaluation only when reversibility of decision was high. Further, this effect was mediated by an inference process, whereby consumers perceived scarcity claims to be either a signal of product value or of manipulative intent. Theoretical and practical implications are discussed.

A Combined Numerical and Experimental Approach to Evaluate the Hardness of AA Aluminum 6063 T6 with A Ni-P Coating

2019 ◽  
Vol 827 ◽  
pp. 209-215
Author(s):  
B. Juan S. León ◽  
Alberto Pertuz ◽  
M. Martínez
Keyword(s):  
Experimental Data ◽  
Experimental Approach ◽  
Brinell Hardness ◽  
Indentation Test ◽  
Contact Radius ◽  
Spherical Indentation ◽  
The Finite Element Method ◽  
Hard Materials ◽  
A Value ◽  
Properties Of Materials

The need to improve the surface properties of materials, has led to the development of parts coated with hard materials deposited on substrates. In this work, by using the finite element method the AA Aluminium 6063 T6 hardness with an error less of the 5 % of the Brinell hardness (HBN), in comparison with the experimental data supplied, was determined. For this, the modelling of a spherical indentation test was carried out, in which the indentation loads and the projected contact radius are obtained from several potential adjustments. Then, using the Lessage-Pertúz model the hardness of the Ni-P coating was determined, obtaining a value of 4.86 GPa.

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