scholarly journals Estudio comparativo entre valores característicos experimentales y normativos de madera aserrada de pino silvestre = Comparative study between experimental and normative values of sawnwood of wild pine

2017 ◽  
Vol 3 (2) ◽  
pp. 39
Author(s):  
Enrique Gómez de la Peña ◽  
Alfonso Cobo Escamilla ◽  
Rafael Lozano Díez ◽  
Oscar López Zaldívar

ResumenEste trabajo realiza un estudio comparativo de caracterización de vigas de madera aserradas y su comparación con la normativa. Para ello se ha utilizado dos tipos de madera muy diferentes, una muy heterogenea, con gran número de defectos, y otra muy homogénea, para comprobar la influencia de los nudos en el comportamiento mecánico de la madera. Para ello se han ensayado un total de 18 vigas de madera y 5 probetas a compresión. Posteriormente se ha realizado una comparativa con la normativa de caracterización, para comprobar su grado de definición. Se ha podido comprobar que dicha norma, se encuentra en el lado de la seguridad en el ámbito de las resistencias, pero que su definición es escasa en cuanto al módulo de elasticidad de la madera.AbstractThis work makes a comparative study of the characterization of sawn timber and its comparison with the standard. For this purpose, two very different types of wood have been used, one very heterogeneous, with a large number of defects, and a very homogeneous one, to verify the influence of the knots on the mechanical behavior of the wood. To this end, a total of 18 wooden beams and 5 test specimens have been tested. Subsequently a comparison has been made with the standardization of characterization, to verify its degree of definition. It has been possible to verify that this norm, is in the side of the security in the field of the resistances, but that its definition is scarce as far as the modulus of elasticity of the wood.

2007 ◽  
Vol 1049 ◽  
Author(s):  
Yuliy Milman ◽  
Sergey Dub ◽  
Alex Golubenko

AbstractThe nanohardness and microhardness testing of crystalline materials with different types of interatomic bonds and different crystal structures was performed with Berkovich indenter.The plasticity characteristics for crystalline materials with different types of interatomic bonds and different crystalline structures were determined by microindentation and by nanoindentation. The relation between these characteristics and parameters of material (Meyer hardness, Young's modulus and Poisson's ratio) was assigned. Plasticity characteristic may be used for characterization of mechanical behavior of materials which are brittle at standard mechanical tests and for coatings.


Author(s):  
J.B. Posthill ◽  
R.P. Burns ◽  
R.A. Rudder ◽  
Y.H. Lee ◽  
R.J. Markunas ◽  
...  

Because of diamond’s wide band gap, high thermal conductivity, high breakdown voltage and high radiation resistance, there is a growing interest in developing diamond-based devices for several new and demanding electronic applications. In developing this technology, there are several new challenges to be overcome. Much of our effort has been directed at developing a diamond deposition process that will permit controlled, epitaxial growth. Also, because of cost and size considerations, it is mandatory that a non-native substrate be developed for heteroepitaxial nucleation and growth of diamond thin films. To this end, we are currently investigating the use of Ni single crystals on which different types of epitaxial metals are grown by molecular beam epitaxy (MBE) for lattice matching to diamond as well as surface chemistry modification. This contribution reports briefly on our microscopic observations that are integral to these endeavors.


2020 ◽  
Vol 70 (12) ◽  
pp. 4594-4600

The purpose of this study was to characterize some types of biomass wastes resulted from different activities such as: agriculture, forestry and food industry using thermogravimetric and ICP-MS analyses. Also, it was optimized an ICP-MS method for the determination of As, Cd and Pb from biomass ash samples. The ICP-MS analysis revealed that the highest concentration of metals (As, Cd, Pb) was recorded in the wood waste ash sample, also the thermogravimetric analysis indicated that the highest amount of ash was obtained for the same sample (26.82%). The biomass wastes mentioned in this study are alternative recyclable materials, reusable as pellets and briquettes. Keywords: ash, biomass, ICP-MS, minor elements, TG


1977 ◽  
Vol 79 (1) ◽  
pp. 133-140 ◽  
Author(s):  
H. M. Meddick

SUMMARYThe ability of six different types of contamination control mats currently in use at the entrances to theatre suites and other clean areas to remove bacteria-carrying particles from theatre trolley wheels was compared. Marked differences in the effectiveness of this property were obtained; and all mats showed some disadvantages. Modification of one of the mats has resulted in improved efficiency under working conditions.


2021 ◽  
Vol 92 (1) ◽  
Author(s):  
Bruna B. Przybulinski ◽  
Rodrigo G. Garcia ◽  
Maria Fernanda de C. Burbarelli ◽  
Claudia M. Komiyama ◽  
Deivid Kelly Barbosa ◽  
...  
Keyword(s):  

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