Search results for "0205 materials engineering"

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…

Gas bubbles and liquid metal flow influenced by uniform external magnetic field

2017

Permanent magnet centrifugal pump for liquid aluminium stirring

2016

In liquid aluminium processing, it is important to ensure continuous mixing of the molten metal to ensure temperature and composition homogeneity, and to improve degassing of the metal. Aluminium and its alloys are often processed in special degassing chambers after preparation in order to avoid segregation and to improve material structure, and to avoid gas pores. This extra step increases material costs and may cause material contamination. In this article, we present the idea to use centrifugal permanent magnet stirrer to induce liquid aluminium motion through thick furnace wall by creating high-speed local liquid metal jet. Analytical estimation, numerical modelling and experimental tes…

Permanent magnet dipole stirrer for aluminium furnaces

2018

Use of permanent magnet systems for metallurgical applications have been proposed before. We have continued development of such systems by investigation use of single magnetic dipole which is realized as permanent magnet cylinder. Magnet is magnetized orthogonal to its axis and has been mounted to the side of the liquid metal reservoir. System first was modelled using small scale experiment with galinstan melt. Velocity distributions and flow patterns in reservoir using Ultrasound Doppler Anemometer were acquired and will be presented here. Additionally, numerical model using Comsol and Cenos modelling software were developed alongside analytical, non-dimensional estimation calculations. Ex…

Numerical and experimental study of liquid metal stirring by rotating permanent magnets

2018

In this work, we study liquid gallium stirring by rotating permanent magnets. We demonstrate possibility of easily creating different flow patterns by rotating permanent magnets, which can be industrially important for controlling heat and mass transfer processes in the system. Unlike the typical approach of simulating magnet rotation as a transient problem and time-averaging the Lorentz forces, we solve the magnet rotation as a harmonic (frequency domain) problem, which leads to forces equal to time-averaged ones and decreases the simulation time considerably. Numerical results are validated using qualitative flow structure results from the neutron radiography visualization of tracer parti…

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.

Natural iron oxide (earth colour) deposits in Latvia: an assessment of the possibilities for their use in inorganic pigment manufacturing

2018

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…

Investigation of absorber and heterojunction in the pure sulphide kesterite

2021

This paper aims to study the properties of the absorber layer and the heterojunction in kesterite solar cells. The Cu2ZnSnS4 (CZTS) thin films were layered on a glass substrate from a colloidal solution of metal salts and thiourea dissolved in a mixture of water and ethanol and deposited by spin coating technique. The samples were then heat treated in a furnace, in the presence of sulphur powder and under a nitrogen gas flow. The results revealed the formation of homogeneous layers of a pure kesterite phase of CZTS crystallites after heat treatment with correct stoichiometry and oxidation states. The optical transmission measurements indicate an energy band-gap of 1.4 eV and an absorption c…