Rosa María Cibrián Ortiz de Anda

Displacement measurements in structural elements by optical techniques

Speckle metrology and holographic interferometry (HI) have been used in several civil engineering applications. We present the results obtained by applying speckle photography (SP) to the study of two quadratic shearwalls with different boundary conditions, and the potential of the technique in the study of this kind of structures is described. The analysis of Youngs fringes obtained with this technique at certain points on each shearwall provides the whole field of displacement measurements. HI has been used to measure the three components of absolute displacement, verifying that the bulging phenomenon does not affect the in-plane components when the applied load remains on the same plane as the shearwall. A qualitative analysis is carried out following an electronic speckle pattern interferometry (ESPI) technique. The results obtained by optical techniques are compared to the numerical results obtained by the finite element method (FEM), finding good correlation between them in all the cases.

Evolución de las características de las arcadas dentarias en dos grupos de edad

Introduccion: se comparan las caracteristicas dimensionales de las arcadas dentarias entre dos grupos de edades diferentes, adolescentes y adultos jovenes. para analizar las variaciones asocia- das a la edad. sexo y a la influencia del tratamiento ortodoncico. Material y metodo: se utilizaron dos muestras: 88 pares de modelos de escayola de adolescentes (edad media 14.05 anos) y 65 de adultos (edad media 22.15 anos). 5e uso un metodo digital para la medicion de los diametros meslodistales de los dientes. distancias intercaninas e intermolares. longitudes de las arcadas y se obtuvo el apinamiento dentario inferior. Para el analisis estadistico se agruparon las muestras de cada grupo de edad por sexos y por tratadoS/no tratados con ortodoncia. Resultados; Los diametros mesiodistales de los chicos eran mayores a los de las chicas y los de los adolescentes mayores que los de los adultos. sobre todo en el sexo femenino. La distancia intercanina disminuyo con la edad en las chicas y la intermolar superior disminuyo en las chicas no tratadas. mientras Que la inferior aumenta en los chicos. Ambas longitudes de arcada tienden a disminuir en ambos sexos y sobre todo en los grupos de no tratados. Existio un aumento del apinamiento inferior con la edad en ambos sexos en los individuos tratados. Conclusiones: la perdida de material dentario con el paso de los anos unido a una mayor perdida de longitud de la arcada podria ser otro factor en el apinamiento terciario. A su vez, el desplazamiento dentario a mesial podria explicar la disminucion de los diametros transversales de canimos y molares, al ocupar una zona mas estrecha del arco dentario.

Determination of strain and stress distribution on shearwalls by using the speckle photography technique

Abstract Speckle photography (SP) is a powerful tool that is adequate to determine small displacements in micrometer range. This information shows other characteristics of structure deformation under loads and can be determined as stress and strain distribution. In this paper we present the results of the application of the SP technique used to study the behaviour of discontinuities in a shearwall model. These structural elements are very important to the stability of buildings. The displacement whole field around the discontinuities and loading points was determined using the pointwise method. This allows us to determine stress distribution at the point of interest by means of the suitable equations. We also present the stress distribution obtained through the finite element method in order to compare the results obtained by means of these two techniques. Good correspondence was found between the displacements determined by both techniques (r=0.982) and also between the stress values we obtained.

Quantification of topographic changes in the surface of back of young patients monitored for idiopathic scoliosis: correlation with radiographic variables.

Abstract. Idiopathic scoliosis requires a close follow-up while the patient is skeletally immature to detect early progression. Patients who are monitored by radiographs are exposed to high doses of ionizing radiation. The purpose of this study is to evaluate if an optic noninvasive method of back surface topography based on structured light would be clinically useful in the follow-up of young patients with idiopathic scoliosis. This could reduce the number of radiographs made on these children. Thirty-one patients with idiopathic scoliosis were submitted twice to radiograph and our topographic method at intervals of 6 months to 1 year. Three topographical variables were applied horizontal plane deformity index (DHOPI), posterior trunk symmetry index (POTSI), and columnar profile (PC). A statistically significant correlation was found between variations of Cobb angle with DHOPI (r=0.720, p<0.01) and POTSI (r=0.753, p<0.01) during the monitoring period. Hence, this topographic method could be useful in clinical practice as an objective adjuvant tool in routine follow-up of scoliosis.

Applications of speckle interferometry to civil engineering in Cuba

Speckle interferometry has been introduced in Civil Engineering at CUJAE in 1988 as a useful technique in research work. This paper describes some applications of speckle interferometry in civil engineering. Speckle photography has been utilized to study deformation in shearwalls, and also studding of behavior building model under concentrate loading. Displacements were numerically calculated using a finite element method. Electronic Speckle Pattern Interferometry (ESPI) has been used for the measurement of the Youngs modulus in mortars and concrete. Obtained values of the Youngs modulus are in good agreement with reported for mortars or measured by a static compressive technique for concrete.

Strains and stress distribution on the shearwall by speckle photography technique

Speckle photography is a powerful tool for measuring displacement fields in micrometer range. In the present paper w use speckle photography technique in the study deformation of a very important structural element in the stability of the buildings: the shearwall. It increase the rigidity of the ensemble and alleviates the working regimen of the columns, that is indispensable in many cases. Also we present the result in the vicinity of one discontinuity on the shear wall model. Displacements on the shearwalls were numerically calculated using a finite element method.

Introduction: Historical Perspective of Infrared Thermography and Its Application in Sport Science

Within the various chapters of this book, the methodology and different applications of infrared thermography in sport science will be discussed. But what are the origins of infrared thermography? What has its development been like in sport science? The present introductory chapter of the book aims to show the historical developments of infrared thermography and, fundamentally, its application in sport science.

Physics Principles of the Infrared Thermography and Human Thermoregulation

Although it is easy to capture a thermal image with infrared thermography, it is necessary to have the basic knowledge about how it works and the physical laws relating to it, as well as the radiative characteristics of the different bodies, and how heat is transferred between space and bodies. This knowledge is essential to establishing a logical hypothesis, using the camera rigorously, and interpreting the thermal data correctly. The aim of this chapter is to present the basic physical principles of infrared thermography, heat transfer and human thermoregulation.

Correlation between Topographic Parameters Obtained by Back Surface Topography Based on Structured Light and Radiographic Variables in the Assessment of Back Morphology in Young Patients with Idiopathic Scoliosis

Study Design Optical cross-sectional study. Purpose To study the correlation between asymmetry of the back (measured by means of surface topography) and deformity of the spine (quantified by the Cobb angle). Overview of Literature The Cobb angle is considered the gold standard in diagnosis and follow-up of scoliosis but does not correctly characterize the three-dimensional deformity of scoliosis. Furthermore, the exposure to ionizing radiation may cause harmful effects particularly during the growth stage, including breast cancer and other tumors. Methods Patients aged 13.15±1.96 years (range, 7–17 years; n=88) with Cobb angle greater than 10° were evaluated with X-rays and our back surface topography method through three variables: axial plane (DHOPI), coronal plane (POTSI), and profile plane (PC). Pearsons correlation was applied to determine the correlation between topographic and radiographic variables. One-way analysis of variance and Bonferroni correction were used to compare groups with different grades of scoliosis. Significance was set at p<0.01 and, in some cases, at p<0.05. Results We detected a positive, statistically significant correlation between Cobb angle with DHOPI (r=0.810) and POTSI (r=0.629) and between PC variables with thoracic kyphosis angle (r=0.453) and lordosis lumbar angle (r=0.275). In addition, we found statistically significant differences for DHOPI and POTSI variables according to the grade of scoliosis. Conclusions Although the back surface topography method cannot substitute for radiographs in the diagnosis of scoliosis, correlations between radiographic and topographic parameters suggest that it offers additional quantitative data that may complement radiologic study.