3,456 research outputs found
Wire Arc Additive Manufacturing (WAAM) Process Analysis on Stainless Steel Built Samples
The increasing developed complexity parts geometry demanded by the industry nowadays, represents a challenge itself, not only for the standard production processes that do not have an answer for it, but also to repair these and other parts in a more cost effectively process with a short delivery period. A technological response to these needs is relying on the Wire Arc Additive Manufacturing (WAAM) process development.
This thesis was developed in Addimadour, an additive manufacturing research platform, located in Bayonne France, that has as objective the development of the Laser Metal Deposition Powder (LMD-P), Laser Metal Deposition Wire (LMD-W), Selective Laser Melting (SLM), ColdSpray – ArcSpray, Fused Deposition Modelling Robotized (FDMR) and Wire Arc Additive Manufacturing (WAAM) technologic processes, procedures, and providing consistent production parameters to industrial partners.
The starting point for this thesis was an extensive research, regarding the chosen material that was a duplex stainless-steel ER2209 applied by WAAM technology. This process consists in deposing layer by layer material through an electric arc with the help of a robot that runs the paths to generate the defined geometry. Relying on an innovator process with lower process temperatures named Cold Metal Transfer (CMT) technology, different experiments were done with the aim to understand the relations between process parameters and results obtained.
Firstly, three experiments were done to establish direct links between input parameters and the shape of depositions achieved. Secondly, other two experiments were done, with the aim of understand the existing dynamic between two or more cords produced together, but also to achieve the best shape possible to ensure the finishing of the surface quality. At last, two walls were produced as a result of all the knowledge collected.
All the experiments done, were followed by analysis and observation of all macroscopic and microscopic specifications. Regarding the microscopic observations and measurements, it was used a microscope and software, specially designed for this type of analysis. Two different mechanical tests were done to the samples with the objective of characterize the material produced by this production process. One was the microhardness test that were carried out in all samples, using a Vickers testing machine. The results of these tests were a pattern and a range of values. For the second test, a three-point flexural test was made on samples, regarding the values of flexural force-displacement to evaluate flexural behaviour of the built samples
Development of new methodologies in sample treatment for proteomics workflow based on enzymatic probe sonication technology and mass spectrometry
Thesis submitted to the Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia, for the degree of Doctor of Philosophy in BiochemistryIn 1994, Marc Wilkins coined the word “Proteome” to define the protein product of the genome, and the word “Proteomics” to describe the science that studies the proteome. Since then, boosted by the development of soft ionization technologies, mass spectrometry and analytical and bioinformatic tools, proteomics has become one of most important and popular scientific fields for the large scale study of complex protein systems. Nowadays, the wide range of proteomics applications include not only the study of biological functions, but also the understanding of changes in cellular regulation mechanisms caused by disease states, biomarker identification for disease diagnosis and development of new drugs or therapeutic approaches. To achieve these goals, most proteomics studies rely on different but complementary tools, such as: two-dimensional gel electrophoresis, chromatographic separation methods, mass spectrometry, stable isotope labeling approaches for protein quantitation, and software for data collection and analysis. However, despite the many technological advances, the procedures used for protein identification and quantitation are still complex, lengthy and laborious. One of the most important steps in any protein identification or quantitation experiment is the digestion, or hydrolysis, of proteins. This crucial step is traditionally performed with proteases, such as trypsin, during 12 to 48 h. Over the years, many techniques have been used to optimize the sample treatment procedures in proteomics, particularly the protein enzymatic digestion stage. The most popular are microwave energy, high-pressure reactors, micro-reactors and immobilized enzymes.
In 2005, ultrasonic energy was used for the first time to enhance protein enzymatic digestion in proteomics workflow. Promising results were obtained: the protein digestion time was reduced from 12 h to only 120 s. Yet, many aspects regarding the application of the ultrasonic energy to the digestion of proteins with enzymes still remain unclear and not fully comprehended.
The major objective of this dissertation was the development and optimization of protocols relying on ultrasonic energy to enhance protein identification and quantitation by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). With this intention, different ultrasonic devices, such as the ultrasonic bath, the ultrasonic probe and the sonoreactor, were used to enhance several steps of the traditional procedures for protein identification by peptide mass fingerprinting (PMF), and protein quantitation by 18O isotopic labeling. Among the different variables assessed throughout this work, the most important were: (i) ultrasound amplitude; (ii) ultrasonication volume; (iii) ultrasonication time; (iv) ultrasound frequency; (v) ultrasonic probe diameter; (vi) protein concentration threshold; and (vii) enzyme-to-protein ratio.In the first part of this study, the experiments were focused on the application of ultrasonic energy to the in-gel protein enzymatic digestion for PMF identification. Different proteins were separated by one-dimensional gel electrophoresis and the corresponding gel bands were processed according to the already established procedures. Protein digestion with trypsin was carried out with different ultrasonic devices: the ultrasonic probe and the sonoreactor.Fundação para a Ciência e a Tecnologia - SFRH/BD/28563/200
Compact simulated countercurrent chromatography for downstream processing of (bio)pharmaceuticals
Dissertação para obtenção do Grau de Doutor em
Engenharia Química e BioquímicaFundação para a Ciência e Tecnologia - PhD gran
Supervisor virtual machine for VoLTE service on a cloud environment
With the continuing growth of Voice of Long Term Evolution (VoLTE) networks,
coupled with the need of Mobile Operators to reduce maintenance costs, Cloud
Service deployment is becoming a common application.
This study was designed to create a method capable of improving the Operations
and Monitoring activities of a VoLTE service that is deployed on a Cloud
platform. In this study, we present contents referring to the constituent elements
of a VoLTE network, and we review in detail the features of the Telephony Application
Server. For this study, TAS used was the Open TAS. Also included in this
study is a generic explanation of Cloud Openstack’s behavior.
The presented method implies the creation of a virtual machine Supervisor
and its deployment in Cloud. This virtual machine is capable of establishing SSH
connections with open TAS to extract the Clear Codes report, which identifies the
state with which calls were terminated for analysis. The virtual machine contains
defined limits, which check if they have been exceeded. If this a limit is excited,
the virtual machine notifies the system operator of an incident.
This study presents the possibilities of implementation in a Cloud environment,
to improve and automate Operations and Maintenance functions in the
Telecommunications network.Com o crescimento contínuo das redes de Voice over Long Term Evolution (VoLTE),
juntamente com a necessidade de redução de custo de manutenção pelos Operadores
Móveis, a implementação do Serviço em Cloud começa a ser uma aplicação
comum.
Este estudo foi elaborado com o intuito de criar um método capaz de melhorar
as atividades de Operações e Monitorização de um serviço de VoLTE, que
esteja implementado numa plataforma Cloud. Neste estudo, encontram-se presentes
conteúdos referentes aos elementos constituintes de uma rede de VoLTE, e é
revisto em detalhe as funcionalidades do Telephony Application Server. Para este
estudo, o TAS utilizado foi o open TAS. Neste estudo, igualmente é incluído uma
explicação genérica do comportamento da Cloud Openstack.
O método apresentado implica criação de uma máquina virtual Supervisor e
da sua implementação na Cloud. Esta máquina virtual é capaz de estabelecer
ligações SSH com o open TAS, de modo a extrair o relatório de Clear Codes,
que identifica o estado com que as chamadas foram finalizadas, para proceder a
análises. A máquina virtual contém limites definidos, os quais verifica se foram
excedidos. Caso este evento seja verificado, notificam o operador do sistema para
um incidente.
Esta é uma proposta que apresenta as possibilidades de implementação num
ambiente de Cloud, em melhorar e automatizar as funções de Operações e Manutenção
na rede de Telecomunicações
The loyalty of European tourists from a destination country perspective
Tourism market represents in many countries a significant weight in its economy.
However, this market tends to be volatile and, in order to ensure economic sustainability,
it is necessary to ensure the loyalty of tourists. Loyalty is influenced by satisfaction and
it's a result of different determinants along the trip.
The ability to analise which tourists are more loyal allows tourism agencies as well as
government organizations to position and change their strategy in order to boost and
increase the loyalty of tourists.
To evaluate the loyalty of the tourists, different analyzes of data mining techniques
were carried out to verify the most loyal tourists, and the type of loyalty. A predictive
model was also created in order to evaluate the influence of socio-demographic variables
on the loyalty of tourists.
In order to do so, it was used three-year data (2014, 2015 and 2016) for the Flash
Eurobarometer, in a specific way, using the "Preferences of European toward tourists"
questionnaire, where were studied data from Europe 28.
Through the techniques mentioned, it was possible to verify, which tourists are the
most loyal and which are the least, as well predict the holiday destination of the tourists.
Finally, it was still possible to see the impact of socio-demographic characteristics on the
loyalty of tourists and their weight.O Mercado do turismo representa em muitos paises um peso significativo na sua
economia. Contudo, este mercado tende a ser volátil e, deste modo, de forma a garantir
uma sustentabilidade económica, é necessário garantir a lealdade dos turistas. A lealdade
é influenciada pela satisfação sendo que esta é resultado de diferentes determinantes ao
longo da viagem.
A possibilidade de verificar quais turistas mais leais permite que as agências de
turismo, assim como as organizações governamentais posicionarem e alterarem a sua
estratégia de forma a potencializar e aumentar a lealdade dos turistas.
De forma a avaliar a lealdade dos turistas, foram realizadas diferentes análises e
tecnicas de data mining de forma a verificar quais os turistas mais leais, e quais os tipos
de lealdade existentes. Foi ainda criado um modelo preditivo de forma a avaliar a
influência das variaveis sócio-demográficas na lealdade dos turistas.
Para tal foram utilizados dados de três anos concecutivos (2014, 2015 e 2016),
referentes aos dados do Flash Eurobarometer, de um modo específico, utilizando o
questionário “Preferences of European toward tourists”, onde foram estudados dados
referentes aos turistas da Europa 28.
Através das tecnicas mencionadas, foi possível verificar quais os turistas mais ou
menos lais assim como prever o destino de férias dos turistas. Por fim, foi ainda possível
ver o impacto das caracteristas socio-demográficas na lealdade dos turistas e qual o seu
peso
Chemical evaluation of Carcavelos fortified wine aged in portuguese (Quercus pyrenaica) and french (Quercus robur) oak barrels at medium and high toast
Adega do Casal Manteiga is a winery, publicly owned by the Municipality of Oeiras that produces Carcavelos
fortified wine. Carcavelos fortified wine is an appellation of origin and demarcated as D.O.P. (Denominação de
Origem Protegida). This study examines the effects of barrels made from botanical species (Quercus pyrenaica, and
Quercus robur) and toasting method (medium and high) on a single vintage wine that has been aged for 8 years.
Twenty barrels were used, with five replicates for each factor. The barrels were fabricated and toasted using the
same cooperage, J.M. Gonçalves in Portugal. Significant differences were seen between the species Q. robur and
Q. pyrenaica, with an impact on total phenolic content, including both flavonoids and non-flavonoids. The total
phenols of the wine aged in Q. pyrenaica barrels was significantly higher than in the Q. robur barrels, and
Q. pyrenaica contained more flavonoids than Q. robur in medium and high toast barrels. Q. pyrenaica showed more
non-flavonoid compounds than Q. robur inhigh and medium toasted barrels, but this difference in non-flavonoids
was only statistically significant in the high toasted barrels. The degree of toasting had significant effects on the
flavonoid content of the wine, as well as the tanning power. Flavonoid content increased for both Q. pyrenaica and
Q. robur in the wines that were aged in high tasted barrels compared to those that were medium toasted. The tannin
power decreased for both Q. pyrenaica and Q. robur when the toasting increasedinfo:eu-repo/semantics/publishedVersio
Análise das modificações proposta pelo IASB e FASB sobre a contabilização do leasing – um estudo do “discussion paper leases – preliminary views”
Desde seu surgimento, a caracterização das operações de leasing tem suscitado
complexas discussões, boa parte relacionada à questão da posse (controle) e da
propriedade. Apesar dos avanços alcançados com a publicação de regulamentos e
padrões nacionais e internacionais voltados para o tratamento contábil desses valores, o
fato é que ainda existem diferentes abordagens que demandam alinhamento conceitual,
principalmente considerando a realidade de um mundo globalizado. Este estudo tem por
objetivo examinar o quadro evolutivo das discussões entre IASB e FASB sobre o
desenvolvimento de um novo padrão internacional conjunto para as operações de leasing.
Trata-se de ensaio baseado em pesquisa bibliográfica e documental acerca da análise
das discussões e encontros realizados entre IASB e FASB entre julho de 2001 e agosto
de 2010, e da sua conformidade com os conceitos vigentes de ativos e passivos. A
justificativa para o estudo está na percepção de que as operações de leasing representam
importante fonte de financiamento para as empresas, e que, num cenário global, a
existência de diferentes padrões contábeis pode prejudicar a qualidade da informação
contábil e reduzir a comparabilidade dos relatórios financeiros. A inovação consiste em
apresentar como os padrões internacionais em vigor diferem-se entre si e de como as
discussões internacionais têm sido conduzidas para a elaboração de um novo padrão
conjunto. Conclui que a dificuldade em determinar o momento em que uma simples
locação transforma-se em compra e a observância da “essência sobre a forma” ainda
exigirão esforços do IASB e FASB para a adequada caracterização dos ativos e passivos
no desenvolvimento de um novo padrão internacional para as operações de leasing. _________________________________________________________________________________ ABSTRACTSince its inception, the characterization of leasing operations has raised complex
discussions, most related to the question of ownership (control) and the property. Despite
the advances achieved with the publication of regulations and national and international
standards aimed at the accounting treatment of these values, the fact is that there are still
different approaches that require conceptual alignment, especially considering the reality
of a globalized world. This study aims to examine the evolutionary framework of
discussions between FASB and IASB on the development of a new international standard
set for leasing transactions. This is essay based on a literature review and documentary
about the discussions and meetings between the IASB and FASB between July 2001 and
August 2010, and their compliance with the current concepts of assets and liabilities. The
rationale for the study is the perception that leasing transactions represent an important
source of financing for companies, and that in a global scenario, the existence of different accounting standards can affect the quality of accounting information and reduce the
comparability of financial reports . The innovation is to show how the existing international
standards differ among themselves and how international discussions have been
conducted for developing a whole new standard. Concludes that the difficulty in
determining when a simple rental becomes a purchase and the observance of "substance
over form" still require the efforts of FASB and IASB to the proper characterization of
assets and liabilities in the development of a new international standard for leasing
transactions
Application of RFID Technology in Public Sectors in Brazil
RFID technology is a technology of 4.0 Industry that seeks to support logistical management by enabling data communication and allowing enhanced control of managed goods from a certain institution. One way of application is in Asset Management, granting a greater efficiency in public management, security, control and automation. This project aims to analyze the scientific production published in association to related aspects of the RFID technology at public agencies in Brazil. A systematic literature review was carried out in Science Direct and Google Scholar databases between the years 2015 and 2020. There was a total of 17 studies that addressed the RFID application in the management of mobile assets at public agencies in Brazil, which most of them being application proposals at Public Universities and Army, where the concentration of these chattel are bigger and demonstrates the efficiency of this technology on controlling tracked goods, exploiting all the advantages that this system makes possible
Water stress and stress recovery of Portuguese maize cultivars
Poster apresentado na conferência "InterDrought II - the 2nd International Conference on Integrated Approaches to Sustain and Improve Plant Production Under Drought Stress", realizada em Roma, Itália, em Setembro de 2005.Water stress is the most important limitation to plant productivity. The development of drought resistant cultivars has become extremely important as we face the dramatic climate changes over the last years. Maize is one of the world’s most cultivated crops, but its production is limited to warm regions, where water limitation is often common.
In six Portuguese maize cultivars (AD3R, PB64, PB260, PB269, PB304, PB369), from different regions of Portugal, drought was imposed, over one week, withholding water supply. Supply of water was restored afterwards and the plants studied for another week. Gas exchange and chlorophyll fluorescence measurements were made. Relative water content (RWC) was assessed as a measure of plant water status.
In control plants, RWC was superior to 90% in all cultivars but stressed plants showed a strong decrease, especially in PB260. Photosynthesis reached values close to zero after a week of stress and all cultivars recovered, with the exception of PB369. The same pattern was observed in transpiration and stomatal conductance. AD3R showed the highest water use efficiency (WUE) and PB64 the lowest. The maximum potential photochemical efficiency of photosystem II and the photochemical quenching showed a small decrease in the last day of stress in all cultivars. The non-photochemical quenching remained constant. The electron transport rate decreased but recovered in all cultivars.
PB269 seems to be the cultivar most tolerant to drought, showing the highest rates of photosynthesis and an intermediate WUE. On the contrary, PB369 seems to be the most susceptible cultivar to water stress
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