67 research outputs found
Consideraciones juridicas entorno al consentimiento en la Ley 19.451.
47 h. ; 28 cm.Este trabajo aborda algunos elementos de la ley 19.451 sobre trasplantes
de órganos.
El primer capítulo desarrolla algunas generalidades en torno a la ley
19.451 y a los trasplantes de órganos.
El segundo capítulo aborda la problemática de la muerte cerebral tanto en
sus aspectos generales, como en el derecho español y chileno.
El tercer capítulo desarrolla la problemática de la validez del
consentimiento de donar según la ley 19.451.
Finalmente, el cuarto capítulo desarrolla algunos elementos básicos de la
llamada “socialización del cadáver”
Using acoustic testing to estimate strength and stiffness of wood-polymer composites
This study used non-destructive testing with ultrasonic and stress wave propagation to evaluate bending strength and stiffness of wood-polymer composites. Twelve composite plate products were produced with different formulations of polymer matrix (high- and low-density polyethylene and polypropylene) and type and proportion of flour (coconut shell and wood). Mechanical and acoustic properties were influenced primarily by the type of matrix used in the composite. The greater the proportion of wood and coconut shell flour the higher the wave propagation velocity, stiffness, and strength. We found a correlation between mechanical properties (strength and stiffness) and wave velocity and stiffness coefficient. We also present linear regression equations of the stiffness and strength of the specimen as a function of wave velocity and stiffness coefficient obtained through non-destructive testing. For polypropylene and high-density polyethylene matrix composites, the stiffness coefficient provided a better estimate of stiffness, while for low-density polyethylene the wave velocity provided better results
Relacion entre la edad de aparacion de la primera palabra y puntaje Apgar
50 p.En el presente estudio se relacionó la edad de aparición de la primera palabra con una variable subjetiva y que se conoce en los primeros instantes de vida de cada ser humano como es el puntaje del test Apgar, con el objetivo de buscar predictores tempranos de algún tipo de alteración del lenguaje. Para esta investigación se seleccionó una muestra aleatoria de todos los menores que a marzo del 2008 tuviesen entre 18 y 24 meses de edad; y que asistieran a alguno de los seis Centros de salud familiar (CESFAM) y Centros de salud comunitario y familiar (CESCOF) de la ciudad de Talca. Luego de analizar los datos se pudo comprobar que no existe ninguna relación entre las variables estudiadas, cada una se comporta de forma independiente sin existir efecto del puntaje Apgar sobre la edad de aparición de la primera palabra. Considerando que no existen estudios al respecto, éste se presenta como el puntapié inicial en la búsqueda de predictores del desarrollo del lenguaje en los menores con el fin de detectar de forma temprana posibles alteraciones del lenguaje y de ésta forma implementar programas de estimulación que eviten dichas alteraciones
In situ acoustic methods to estimate the physical and mechanical aging of oriented strand board
Following the success achieved in previous research projects usin non-destructive methods to estimate the physical and mechanical aging of particle and fibre boards, this paper studies the relationships between aging, physical and mechanical changes, using non-destructive measurements of oriented strand board (OSB). 184 pieces of OSB board from a French source were tested to analyze its actual physical and mechanical properties. The same properties were estimated using acoustic non-destructive methods (ultrasound and stress wave velocity) during a physical laboratory aging test. Measurements were recorded of propagation wave velocity with the sensors aligned, edge to edge, and forming an angle of 45 degrees, with both sensors on the same face of the board. This is because aligned measures are not possible on site. The velocity results are always higher in 45 degree measurements. Given the results of statistical analysis, it can be concluded that there is a strong relationship between acoustic measurements and the decline in physical and mechanical properties of the panels due to aging. The authors propose several models to estimate the physical and mechanical properties of board, as well as their degree of aging. The best results are obtained using ultrasound, although the difference in comparison with the stress wave method is not very significant. A reliable prediction of the degree of deterioration (aging) of board is presented
Wood Density and Moisture Content Estimation by Drilling Chips Extraction Technique
Producción CientíficaThe novelty of this study is the development of an accurate wood moisture content (MC) estimation method based on a relatively brand-new, non-destructive testing technique (drilling chips extraction). The method is especially important in the assessment of existing timber structures, where non-destructive testing (NDT) results are affected by wood MC and should be adjusted to a reference MC, usually 12%. In the assessment of timber structures, it is not possible to determine MC by oven drying method and this should be estimated. Electrical resistance and capacitance are the conventional methods used for MC estimation. This research work aims to present an accurate MC estimation method based on the drilling chips extraction technique. For that, 99 specimens (90 × 65 × 38 mm3) from three softwood and hardwood species covering a wide range of densities (from 355 to 978 kg m−3) were tested after conditioning at five different MCs (5%, 10%, 15%, 20%, 25%). The Wood Extractor device based on the drilling chips extraction technique was used. The mass of the chips collected (drilling residue) from each drill was recorded. The results show that the MC of the chips extracted was statistically significantly different than the MC of the specimen and cannot be directly used as MC determination. However, the chips MC can be used as an estimator of specimen MC with high determination coefficients (R2 from 71% to 86%). As the main result, models to estimate density directly adjusted to a reference 12% MC from the wet and dry mass of chips extracted were developed with an R2 of 98%. In sum, the drilling chips extractor is a dependable and straightforward method to estimate MC and density from only one measurement. Density adjusted to a reference 12% MC can be directly estimated from a single model.Ministerio de Economía, Industria y Competitividad (project BIA2014-55089-P)Asociación de Investigación Técnica de la Madera (projects AITIM-Fucovasa 2012–2013 and AITIMFucovasa 2014–2015
Wood Density Determination by Drilling Chips Extraction in Ten Softwood and Hardwood Species
Producción CientíficaResearch Highlights: The novelty of this study is the development of an accurate wood density estimation method based on a relatively brand new semi-destructive testing technique (drilling chips extraction). This method is especially crucial in the assessment of existing timber structures. Background and Objectives: Probing, drilling, and coring are non-destructive and semi-destructive techniques commonly used for timber density estimation in existing timber structures. Most of these techniques show poor or medium accuracy or are so expensive or destructive. This paper aims to obtain accurate estimation models for wood density in existing structures using the easy to use drilling chips extraction technique. Materials and Methods: 300 specimens (95 × 65 × 200 mm3) from ten softwood and hardwood species covering a wide range of density (from 350 to 980 kg·m−3) were tested after conditioning. The Wood Extractor device based on the drilling chips extraction technique was used in the radial and the tangential direction. Mass of the chips collected (drilling residue) from each drill was recorded. Results: Density obtained from drilling residue was not statistically significantly different between radial and tangential directions avoiding take into account direction when measuring. The density obtained in the whole specimens is slightly higher than the density obtained by drilling residue being this difference uniformly through the range of densities studied. Two different estimation models were presented with high determination coefficients (96% and 97%) and low standard errors. These results were similar to those obtained by other authors using core drilling but causing less damage. Conclusions: Drilling chips extractor is a simple, reliable and inexpensive method to estimate density in existing structures with accuracy.Ministerio de Economía, Industria y Competitividad (project BIA2014-55089-P)Asociación de Investigación Técnica de la Madera (projects AITIM-Fucovasa 2012–2013 and ITIM Fucovasa 2014–2015
NDT to identify biological damage in wood
Nondestructive techniques are widely used to assess existing timber structures. The models proposed for these methods are usually performed in the laboratory using small clear wood specimens. But in real situations many anomalies, defects and biological damage are found in wood. In these cases the existing models only indicate that the values are outside normality without providing any other information. To solve this problem, a study of non-destructive probing methods for wood was performed, testing the behaviour of four different techniques (penetration resistance, pullout resistance, drill resistance and chip drill extraction) on wood samples with different biological damage, simulating an in-situ test. The wood samples were obtained from existing Spanish timber structures with biotic damage caused by borer insects, termites, brown rot and white rot. The study concludes that all of the methods offer more or less detailed information about the degree of deterioration of wood, but that the first two methods (penetration and pullout resistance) cannot distinguish between pathologies. On the other hand, drill resistance and chip drill extraction make it possible to differentiate pathologies and even to identify species or damage location. Finally, the techniques used were compared to characterize their advantages and disadvantages
Relação entre o biótipo de vacas Holando, a estratégia de alimentação e a saúde do úbere
Mastitis frequency could be affected by animal and environmental conditions such as dairy cow genetics and feeding strategies. Thus, the objective of this study was to analyze the probability of clinical mastitis and somatic cell count (SCC) for New Zealand (NZ) and North American (NA) Holstein-Friesian cows maintained on two different feeding strategies (pasture or mixed). A total of 120 cows from the experimental dairy farm of the National Agricultural and Livestock Research Institute (INIA, by its Spanish acronym) (Colonia, Uruguay) were grouped into four groups derived from the combination of two feeding strategies: Grass Maximum or Grass Fixed, and two Holstein strains: NZ or NA (n=30). Clinical mastitis and SCC were evaluated monthly during a whole lactation period. There was an interaction between the Holstein strains and parity for clinical mastitis (P=0.04). The NA primiparous cows were the least likely to suffer clinical mastitis (OR: 0.003), while NA multiparous cows were the most likely to show clinical mastitis (OR: 0.12). The NZ cows reported intermediate values of OR (primiparous: 0.082, multiparous: 0.066). Feeding strategies did not affect clinical mastitis or SCC. Similar SCC was found for NZ and NA strains. In conclusion, regardless of the feeding strategy, the probability of clinical mastitis differed by the genetic origin of the Holstein cows. However, this difference was influenced by parity. The SCC was not influenced by the Holstein strain or the feeding strategy.Factores relacionados con el animal y el ambiente pueden afectar la frecuencia de mastitis, siendo la genética y la estrategia de alimentación algunos de dichos factores. El objetivo de este estudio fue analizar la frecuencia de mastitis clínica y los recuentos de células somáticas (RCS) de vacas Holando de dos biotipos, Norteamericano (NA) y Neozelandés (NZ), bajo dos estrategias de alimentación (pastura o mixto). En la Unidad Experimental de Lechería de INIA La Estanzuela (Colonia, Uruguay) fueron agrupadas 120 vacas en 4 tratamientos según la combinación de biotipo y estrategia de alimentación (n=30). La cantidad de vacas con mastitis clínica y los RCS fueron registrados mensualmente durante una lactación. Hubo una interacción entre el biotipo y la paridad de las vacas (primíparas y multíparas) (P=0,04) para la frecuencia de mastitis. Vacas primíparas NA presentaron menor probabilidad de presentar mastitis clínica (ODR: 0,003). Por el contrario, las vacas multíparas NA fueron las que presentaron mayor probabilidad de experimentar mastitis clínica (ODR: 0,12), mientras que las vacas de origen NZ mostraron valores intermedios (ODR primíparas: 0,082; ODR multíparas: 0,066). La estrategia de alimentación no afectó la frecuencia de mastitis ni los RCS. Tampoco el biotipo afectó el RCS. En conclusión, sin importar la estrategia de alimentación, la frecuencia de mastitis clínica fue diferente según el biotipo, pero estas diferencias fueron influenciadas por el número de partos de los animales. Los RCS no fueron afectados por la estrategia de alimentación o el biotipo animal.A genética e os sistemas de alimentação são fatores que afetam a incidência de mastite. Portanto, o objetivo deste estudo foi analisar a incidência de mastite clínica e a contagem de células somáticas (CCS) de vacas holandesas de dois biótipos, norte-americana (NA) e neozelandês (NZ), sob dois sistemas de alimentação (pastejo fixo ou máximo). Na Unidade Experimental do INIA La Estanzuela (Colonia, Uruguay) 120 vacas foram distribuídas em 4 tratamentos de acordo com a combinação de biótipo e alimentação (n = 30). O número de vacas com mastite clínica e a CSS foram registrados mensalmente durante uma lactação. Houve interação entre o biótipo e a paridade das vacas (P = 0,04) na frequência de mastite. Vacas primíparas NA apresentaram menor probabilidade de apresentarem mastite clínica (ODR: 0,003). Em contraste, as vacas multíparas NA tiveram a maior probabilidade de experimentar mastite clínica (ODR: 0,12), sendo as vacas de origem NZ os animais com valores intermédios (ODR primíparas: 0,082; ODR multíparas: 0,066). O sistema de alimentação não afetou a frequência de mastite ou CCS. O biótipo também não afetou a CCS. Em conclusão, independente do sistema de alimentação, a frequência de mastite foi diferente de acordo com o biótipo, mas essas diferenças foram influenciadas pela paridade dos animais. A CCS não foi afetada pelo sistema de alimentação ou biótipo animal
On rational cuspidal projective plane curves
In 2002, L. Nicolaescu and the fourth author formulated a very general conjecture which relates the geometric genus of a Gorenstein surface singularity with rational homology sphere link with the Seiberg--Witten invariant (or one of its candidates) of the link. Recently, the last three authors found some counterexamples using superisolated singularities. The theory of superisolated hypersurface singularities with rational homology sphere link is equivalent with the theory of rational cuspidal projective plane curves. In the case when the corresponding curve has only one singular point one knows no counterexample. In fact, in this case the above Seiberg--Witten conjecture led us to a very interesting and deep set of `compatibility properties' of these curves (generalising the Seiberg--Witten invariant conjecture, but sitting deeply in algebraic geometry) which seems to generalise some other famous conjectures and properties as well (for example, the Noether--Nagata or the log Bogomolov--Miyaoka--Yau inequalities). Namely, we provide a set of `compatibility conditions' which conjecturally is satisfied by a local embedded topological type of a germ of plane curve singularity and an integer if and only if the germ can be realized as the unique singular point of a rational unicuspidal projective plane curve of degree . The conjectured compatibility properties have a weaker version too, valid for any rational cuspidal curve with more than one singular point. The goal of the present article is to formulate these conjectured properties, and to verify them in all the situations when the logarithmic Kodaira dimension of the complement of the corresponding plane curves is strictly less than 2
The effect of moisture content on nondestructive probing measurements
When assessing existing timber structures it is not possible to obtain density as the ratio mass/volume, so nondestructive probing methods are used to predict density. As in other nondestructive techniques, moisture content influences measurements. The goal of this paper is to study the influence of timber moisture content on two nondestructive probing techniques (penetration resistance and pullout resistance). 25 large cross section specimens of laricio pine from Spain were measured. The moisture content ranged from 65.1% to 8.3%. Penetration depth decreases and screw withdrawal strength increases when moisture content decreases below the fiber saturation point. There are lineal tendencies in both techniques. No moisture content influence was found in measures above fiber saturation point
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