Sintering response and mechanical properties of microwave sintered 316L Powder Blends

Microwave sintering can be an efficient, economic and valuable approach for the processing of some PM materials. Recent findings on the ability of powdered metals to absorb and dissipate microwave radiation, opened new opportunities for the PM world. Being the particle size of the metallic powders one of the key parameters that rules the heating rate and the temperature performance during microwave sintering, work has been carried out on compacts of 316L powder blends with 60, 50, 25 and 7 m mean particle sizes, at 1150ºC for 30 minutes in a 2.45 GHz-1000 W microwave oven. Green and sintered densities and corresponding transverse rupture strength (TRS) are reported as well as hardness and porosity. Densities in excess of 95% were attained for the finer powders. TRS tests were performed on all but the 7 m powder specimens, being the highest value of 630 MPa obtained for the 25 m powder specimen

Scale up of microwave annealed FA0.83Cs0.17PbI1.8Br1.2 perovskite towards an industrial scale

ABSTRACT: Perovskite solar cells (PSCs) efficiency has rapidly increased from the initial 3.8 to recent 24.2%. This high efficiency has attracted serious worldwide researchers and industry attention due to their low material cost, and simple solution-based fabrication process. However, fundamental studies on PSCs are usually produced through lab-scale actions and carried out on small-area devices (≤1 cm2). Here we present the advances of up-scaling using microwave (MW) annealing of perovskite films on large area specimens (~16 cm2), looking forward the industrial-scale. Morphological, structural and optical characterization were performed to confirm the effectiveness of the scaled up MW annealing.info:eu-repo/semantics/publishedVersio

The comeback of the largest player in the cruise industry

This report will provide valuable insights of not only Carnival’s Corporation but also of the Cruise industry in which the company operates regarding top players, industry trends and dynamics that are important to fully understand its valuation. The last chapter reflects our methodology to value Carnival Corporation, by presenting the main inputs that will lead to our target share price

The European Union Financial Transaction Tax : feasibility and desirability

The roots of a Financial Transaction Tax date back to 1936. At that time, Keynes stated that the implementation of an internationally agreed uniform tax over financial transactions could be a solution to control the volatility of financial markets, an idea that was later developed in the 70’s by James Tobin (1972; 1974). Taking into consideration the arguments in favour and against such tax, the European Commission decided to propose the implementation of a common Financial Transaction Tax in the European Union. The main goals of this thesis are to examine the feasibility and desirability of that proposal. In addition, this essay intends to understand which would be the main implications for the European financial sector and how it would react. In order to do so, this dissertation synthesizes and interprets the main arguments in favour and against the proposal present in the economic literature. The results of this study, based on the information available, point out that not only the proposal seems unfeasible and undesirable, but also that European financial institutions would be able to avoid taxation, a situation that would probably generate negative distortions in financial markets. Moreover, this essay also concludes that are other taxation mechanisms - namely the Financial Activities Tax - that better address European Commission’s desires with the measure.As raízes de um imposto sobre as transacções financeiras remontam a 1936. Nesse ano, Keynes referiu que a implementação de um imposto comum sobre as transacções financeiras a nível internacional poderia ser uma solução para controlar a volatilidade nos mercados financeiros, uma ideia que foi mais tarde desenvolvida por James Tobin (1972; 1974). Tomando em consideração os argumentos a favor e contra tal imposto, a Comissão Europeia decidiu propor a implementação de um imposto comum sobre as transacções financeiras na União Europeia. Os principais objectivos desta tese passam por examinar a plausibilidade e a desejabilidade da proposta Europeia. Adicionalmente, este ensaio pretende perceber quais seriam as principais implicações para o sector financeiro Europeu e de que forma este reagiria. Para este efeito, esta dissertação sintetiza e interpreta os principais argumentos a favor e contra a proposta presentes na literatura económica. Os resultados deste estudo, com base na informação disponível, apontam não apenas que a proposta parece inviável e indesejável, mas também que as instituições financeiras Europeias seriam capazes de evitar a tributação, uma situação que provavelmente geraria distorções negativas nos mercados financeiros. Além disso, este ensaio conclui que existem outros mecanismos de tributação – nomeadamente um imposto sobre as actividades do sector financeiro – que vão mais ao encontro dos objectivos da Comissão Europeia com a medida

Effect of vanadium and carbon content on the sinterability of water atomised high speed steel powders

This paper presents the results of an investigation into the sintering behaviour of three vanadium enriched variants of T42 high-speed steel. Powders were prepared by water atomization with vanadium and carbon contents of 6-8 wt% and 2.2 -2.7 wt%, respectively. These were annealed, die pressed and sintered in vacuum. All three alloys were sintered to full density giving "as-sintered" microstructures comprising globular MC carbides dispersed in a martensitic matrix. Optimum sintering temperatures were in the range 1240-1250 degrees C with lower optimum temperatures associated with higher carbon levels. Sintering characteristics are correlated with phase diagrams calculated using ThermoCalc (TM) software and TCFe2000 database. The implications for the design of sinterable vanadium containing high-speed steels are discussed

Greg Young, Reshaping Planning with Culture (Urban and Regional Planning and Development Series)

Reshaping Planning with Culture é uma das mais recentes obras de Greg Young, urbanista experimentado no sector público e privado, historiador e professor do Departamento de Geografia e Ambiente da Macquarie University de Sydney, responsável de vários planos estratégicos australianos no domínio da cultura, do património e do turismo. A sua extensa obra, iniciada nos anos 1980, tem percorrido temas como as relações entre história e conservação, a autenticidade, os valores sociais ou a evolução ..

Charge transport and recombination of dye sensitized 1D nanostructured-TiO2 films prepared by reactive sputtering

Dye sensitized solar cells (DSCs) are governed by light absorption, charge injection, electron transport and recombination and electrolyte diffusion. One way to improve the efficiency of these devices is by the design of highly ordered nanostructured semiconductor materials.The advantages can be two-fold: Firstly charge transport within the metal-oxide can be enhanced and hence thicker films can be employed and secondly, the complete permeation with a solid-state hole-transport medium of the sensitized metal-oxide can be facilitated. Nanostructured materials should promote vectorial electron diffusion and have as few recombination sights as possible so as to further enhance electron lifetimes and electron collection efficiencies. These materials should also have a high surface area so as to allow for efficient dye-loading and hence light absorption. Highly ordered TiO2 nanostructured films were prepared by reactive sputtering and their charge transport characteristics evaluated in DSCs. These were compared to DSCs employing mesoporous TiO2 films prepared by doctor blade technique using commercial paste. Charge transport characteristics were evaluated by impedance spectroscopy (IS), incident photon to current conversion efficiencies (IPCE) and current-voltage (iV) curves under simulated AM1.5G irradiation. Film morphology and structural properties were evaluated by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively

Symptoms Impact and eHealth Intervention for Menopausal Women with Urinary Incontinence

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Aplicação da teoria das restrições na gestão da manutenção

Trabalho final de mestrado para obtenção do grau de mestre em Engenharia MecânicaO presente documento, propõe descrever um modelo de aplicação da Teoria das Restrições nas atividades de gestão da manutenção, sector que é visto, hoje em dia, como um dos fatores predominantes para a obtenção de resultados financeiros de qualquer organização. Este documento, pretende também, mostrar a aplicabilidade em contexto real, deste modelo, numa organização do ramo metalúrgico, em que a manutenção é um dos pontos essenciais para o bom funcionamento, tanto de equipamentos como de instalações. Para que seja possível identificar e resolver, problemas relacionados com as atividades de gestão da manutenção, são sugeridas várias ferramentas (tais como: Ferramentas de Pensamento Lógico, Drum-Buffer-Rope, Critical Chain, entre outras), relacionadas com a Teoria das Restrições, em que são apresentados os prós e contras de cada ferramenta, dando assim a informação de qual a melhor ferramenta, a aplicar, em situações distintas que possam aparecer em cada organização. Neste trabalho, foi feita a análise à situação atual da organização, e a partir dessa análise foi aplicado o modelo desenvolvido. Este modelo permitiu, identificar os problemas relacionados com a gestão, e em seguida, apresentar uma proposta que visa resolver os problemas identificados.This document proposes to describe a model of application of the Theory of Constraints in maintenance management activities, a sector that is nowadays seen as one of the predominant factors for the profit management of any organization. This document also intends to show the applicability in a real context of this model in an organization of the metallurgical branch, where maintenance is one of the essential points for the good functioning of both equipment and facilities. In order to identify and solve problems related to maintenance management activities, several tools are suggested (such as: Logical Thinking Tools, Drum-Buffer-Rope, Critical Chain, among others) related to Theory of Constraints, in which the pros and cons of each tool are presented, thus giving the information of the best tool to apply, in different situations that may appear in each organization. In this work, the analysis was made to the current situation of the organization, and from this analysis the developed model was applied. This model allowed, identify the problems related to management, and then present a proposal that addresses the identified problems.N/