Search results for "020502 materials"
showing 10 items of 27 documents
The effect of curing conditions on the electrical properties of an epoxy resin
2016
An investigation into the fracture behaviour of honeycombs with density gradients
2020
International audience; In this study we perform an experimental and computational investigation about the fracture behaviour of polymer honeycombs presenting gradients in terms of lattice density. Such lattice relative density variations are introduced with the aim of mimicking the micro-morphology encountered in some natural materials, such as several kinds of woods, which seems related to the ability of the corresponding macro-material to delay the propagation of fracture under certain conditions. Starting from the conclusions of previous computational analyses, we perform a few experimental tensile tests on ABS model honeycombs obtained by additive manufacturing, with the aim of getting…
Regarding the influence of the particle size of crumb rubber from waste rubber on the physical and mechanical characteristics of reclaimed rubber
2017
Thus, at present, a large amount of rubber waste cannot be higher harnessed due to recovery technologies used. Also, the requirements for new products of rubber worldwide are greater than the production capacity and the availability of raw materials. To offset this balance is necessary to improve technologies for recycling waste rubber so to can get regenerated rubber with the best mechanical physical characteristics. The main technology for obtaining the regenerated rubber is based on the rubber waste shredding and making the powder, so that it can be carried out de-vulcanization in autoclave. All the time it was monitored as the de-vulcanization process to be as economical and less pollut…
Effect of current on the sintering of pre-oxidized copper powders by SPS
2017
Abstract As mentioned in the literature, SPS (Spark Plasma Sintering) technology combines uniaxial charge and pulsed currents to achieve the rapid sintering of powders. Although the utilization of current is often reported, an understanding of its role in the sintering mechanisms is still a subject of controversy. In fact, the oxide layer around metal particles is sometimes considered to be a dielectric gap in which discharges may occur: these discharges can clean the surface of particles and enhance densification. In this paper, an oxide layer was grown on the particle surface of a copper powder, and the growth enabled the study of the role of current on such dielectric layers. The powders…
Radio frequency shielding of thin aluminized plastic filters investigated for the ATHENA X-IFU detector
2018
Copyright 2018 Society of Photo-Optical Instrumentation Engineers (SPIE). One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited. The X-ray Integral Field Unit (X-IFU) is one of the two detectors of the ATHENA astrophysics space mission approved by ESA in the Cosmic Vision 2015-2025 Science Programme. The X-IFU consists of a large array of transition edge sensors (TES) micro-calorimeters covering a field of view of 5' diameter, sensitive in the energy range 0.2-12 keV, and providing a spectral resolution…
Élites campesinas en el entorno de la ciudad de Valencia: los Castrellenes
2017
This paper seeks to analyse economy of a well-to-do peasant family settled in the urban fringes of the city of Valencia, capital of the kingdom, in the first half of fifteenth Century. The death of the head of the family, due to the plague, made emerge the solidarity of the relatives, who took care of the orphans. Thanks to the memorial of rents we can assess the economic strategies of a wealthier peasant family, the importance of markets and the city and countryside relations.
Sexism, romantic love and gender inequality. A study of Latin American adolescents living in Spain
2019
Este trabajo examina el papel de los factores sociodemográficos como determinantes de las creencias y actitudes sexistas y las percepciones distorsionadas sobre el amor romántico, y analiza la relación entre el sexismo hostil y el sexismo benevolente y las creencias en mitos del amor romántico, según el Índice de Desigualdad de Género (idg), en una muestra de 203 adolescentes latinoamericanos residentes en Valencia (España). This paper examines the role of socio-demographic factors determining both sexist beliefs and attitudes and distorted perceptions of romantic love. Moreover, the relationship between hostile and benevolent sexism, and the belief in myths about romantic love is analyzed …
Sin título
2019
El presente artículo aborda una investigación cualitativa rigurosa cuyos resultados reflejan las causas que generan la vulnerabilidad de niños y adolescentes ante la influencia de las pandillas y cómo estos pasan de víctimas a victimarios. Se describe el papel que juegan los adolescentes en las principales pandillas y los factores que inciden en la responsabilidad del Estado sobre la desprotección de la niñez y la adolescencia. This article addresses a rigorous qualitative research whose results reflect the causes that generate the vulnerability of children and adolescents to the influence of gangs and how they pass from victims to victimizers. It describes the role played by adolescents in…
Local uniqueness of the solutions for a singularly perturbed nonlinear nonautonomous transmission problem
2020
Abstract We consider the Laplace equation in a domain of R n , n ≥ 3 , with a small inclusion of size ϵ . On the boundary of the inclusion we define a nonlinear nonautonomous transmission condition. For ϵ small enough one can prove that the problem has solutions. In this paper, we study the local uniqueness of such solutions.
Comparison of spring characteristics of titanium-molybdenum alloy and stainless steel
2017
Background Titanium-molybdenum alloy (TMA) and stainless steel (SS) wires are commonly used in orthodontics as arch-wires for tooth movement. However, plastic deformation phenomenon in these arch-wires seems to be a major concern among orthodontists. This study aimed to compare the mechanical properties of TMA and SS wires with different dimensions. Material and Methods Seventy-two wire samples (36 TMA and 36 SS) of three different sizes (19×25, 17×25 and 16×22) were analyzed in vitro, with 12 samples in each group. Various mechanical properties of the wires, including spring-back, bending moment and stiffness were determined using a universal testing machine. Student’s t-test showed statis…