scholarly journals Validación de un dispositivo Wireless para el control de variables cinemáticas en el rendimiento deportivo

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Samuel Jose Gaviria ◽  
Andrés Felipe Ramirez ◽  
Leon Mauricio Rivera
Keyword(s):  

Validar un dispositivo Wireless para el censo de la aceleración en actividades deportivas. Para la validación se usó un transductor lineal (T-Force System Ergotech) y análisis de videografía (SkillSpector ). Participantes desarrollaron el press de banca plana en una maquina SMITH. El protocolo consistió en realizar una repetición de press de banca plana con una carga constante (18 kg). La recuperación entre cada repetición fue de 15 segundos. En total 5 sujetos desarrollaron 84 repeticiones.  Los datos estuvieron caracterizados por una diferencia menor entre los valores de la media del dispositivo Wireless vs T-Force (0,18) en contraste con Wireless vs Videografía (0,46). Los resultados muestran que no existen diferencias estadísticamente significativas en la aceleración de desplazamiento entre el dispositivo Wireless, transductor lineal y análisis de videografía; sin embargo, los niveles de correlación de Pearson que se reportaron manifestaron una asociación moderada (p<0,05) para las dos pruebas. El supuesto de independencia de los errores fue contrastado mediante la prueba de Durbin-Watson. Los resultados sugieren que, si bien no se presentaron altas asociaciones entre los dispositivos, el factor económico de la producción del dispositivo Wireless, lo hace una alternativa viable para el control y medición de la aceleración en la práctica deportiva.

2020 ◽  
Vol 12 (11) ◽  
pp. 1249-1254
Author(s):  
Long Qin ◽  
Qiao Wang ◽  
Dongliang Zhang ◽  
Xin He ◽  
Binbin Wu

The different positions and angles of attachment affecting the buccolingual movement of the maxillary molars, especially lingual tipping and negative torque movements, were biomechanically analyzed in order to determine how to better control and prevent unwanted movement of clear aligners. The aligner can be designed and placed appropriately to improve expected tooth movement. Based on mechanical principles, the force system of attachment was analyzed, and the optimum attachment position and angle for tipping and negative torque movement was determined. Attachment close to the enamel-cementum junction (ECJ) was found to achieve the best F (M/L) during negative torque movement; however, the angle should also be adjusted. Attachment close to the occlusal surface achieved greater tipping force at specific angles. When more tipping movement is required, it is recommended to place the attachment 3–5 mm from the ECJ. The angle of the attachment should be 110–120 degrees from the tooth surface. When place the attachment 4–5 mm from the ECJ, the angle of the attachment should be between 145 and 146.5 degrees.


2017 ◽  
Vol 11 (1) ◽  
pp. 466-475 ◽  
Author(s):  
Taísa Boamorte Raveli ◽  
Dirceu Barnabé Raveli ◽  
Kelei Cristina de Mathias Almeida ◽  
Ary dos Santos Pinto

Background: Tipped lower molar over edentulous space is very common in orthodontics practice when adults seek treatment. The segmented arch technique features a predictable force system that provides a controlled release of force that can produce light and continuous tooth movement. Case Description: A female adult patient, who lost a permanent lower first molar, needed correction of the position of her permanent first molar place. Instead of making space for rehabilitation, it was closed after second molar uprighting and a balanced interdigitation was created without prosthetics. The patient was successfully treated with segmented arch technique using root correction spring activated with geometry VI to promote uprighting of a tipped molar and Niti spring coil to promote space closure. Practical Implications: Segmented arch technique is known to provide predictable light and continuous forces, which is very much indicated in adult treatment. There are several things to consider when orthodontically treating adult patients. Their periodontal conditions might not be ideal, less bone apposition may occur, and side effects of orthodontic tooth movement are expected. Thus, a predictable and controlled orthodontic treatment is needed.


2019 ◽  
Vol 2019 (2) ◽  
pp. 7-16
Author(s):  
Zygmunt Mikno ◽  
Szymon Kowieski ◽  
Adam Pilarczyk

2021 ◽  
Vol 9 ◽  
Author(s):  
Rebeca González-Cabaleiro ◽  
Jake A. Thompson ◽  
Laia Vilà-Nadal

Fast and reliable industrial production of ammonia (NH3) is fundamentally sustaining modern society. Since the early 20th Century, NH3 has been synthesized via the Haber–Bosch process, running at conditions of around 350–500°C and 100–200 times atmospheric pressure (15–20 MPa). Industrial ammonia production is currently the most energy-demanding chemical process worldwide and contributes up to 3% to the global carbon dioxide emissions. Therefore, the development of more energy-efficient pathways for ammonia production is an attractive proposition. Over the past 20 years, scientists have imagined the possibility of developing a milder synthesis of ammonia by mimicking the nitrogenase enzyme, which fixes nitrogen from the air at ambient temperatures and pressures to feed leguminous plants. To do this, we propose the use of highly reconfigurable molecular metal oxides or polyoxometalates (POMs). Our proposal is an informed design of the polyoxometalate after exploring the catabolic pathways that cyanobacteria use to fix N2 in nature, which are a different route than the one followed by the Haber–Bosch process. Meanwhile, the industrial process is a “brute force” system towards breaking the triple bond N-N, needing high pressure and high temperature to increase the rate of reaction, nature first links the protons to the N2 to later easier breaking of the triple bond at environmental temperature and pressure. Computational chemistry data on the stability of different polyoxometalates will guide us to decide the best design for a catalyst. Testing different functionalized molecular metal oxides as ammonia catalysts laboratory conditions will allow for a sustainable reactor design of small-scale production.


2021 ◽  
Vol 18 ◽  
pp. 100163
Author(s):  
Zhuo Qu ◽  
Hai Lin ◽  
Weijun Huang ◽  
Xiang Ren
Keyword(s):  

2015 ◽  
Vol 16 (9) ◽  
pp. 740-743 ◽  
Author(s):  
HP Raghuveer ◽  
M Hemanth ◽  
MS Rani ◽  
Chathura Hegde ◽  
B Vedavathi ◽  
...  

ABSTRACT Background Orthodontic tooth movement occurs due to various biomechanical changes in the periodontium. Forces within the optimal range yield maximum tooth movement with minimum deleterious effects. Among various types of tooth movements, extrusion and rotational movements are seen to be associated with the least amount of root resorption and have not been studied in detail. Therefore in this study, the stress patterns in the periodontal ligament (PDL) were evaluated with extrusion and rotational movements using the finite element method FEM. Materials and methods A three-dimensional (3D) FEM model of the maxillary incisors was generated using SOLIDWORKS modeling software. Stresses in the PDL were evaluated with extrusive and rotational movements by a 3D FEM using ANSYS software with linear material properties. Results It was observed that with the application of extrusive load, the tensile stresses were seen at the apex, whereas the compressive stress was distributed at the cervical margin. With the application of rotational movements, maximum compressive stress was distributed at the apex and cervical third, whereas the tensile stress was distributed on cervical third of the PDL on the lingual surface. Conclusion For extrusive movements, stress values over the periodontal ligament was within the range of optimal stress value as proposed by Lee, with a given force system by Profitt as optimum forces for orthodontic tooth movement using linear properties. During rotation there are stresses concentrated at the apex, hence due to the concentration of the compressive forces at the apex a clinician must avoid placing heavy stresses during tooth movement. How to cite this article Hemanth M, Raghuveer HP, Rani MS, Hegde C, Kabbur KJ, Vedavathi B, Chaithra D. An Analysis of the Stress Induced in the Periodontal Ligament during Extrusion and Rotation Movements: A Finite Element Method Linear Study Part I. J Contemp Dent Pract 2015;16(9):740-743.


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