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[en] DETERMINATION OF AS AND MN IN DIESEL, GASOLINE E NAPHTHA BY GF AAS AND OF CU, FE, NI AND V IN PETROLEUM USING SS-GF AAS / [pt] DETERMINAÇÃO DE AS E MN EM DIESEL, GASOLINA E NAFTA POR GF AAS E DE CU, FE, NI E V EM PETRÓLEO UTILIZANDO SS-GF AASGEISAMANDA PEDRINI BRANDAO 01 April 2008 (has links)
[pt] O petróleo é uma mistura complexa de hidrocarbonetos (50 a
95 por cento)
contendo traços de compostos inorgânicos (principalmente de
S, N, O e metais
pesados). Elementos traço são normalmente encontrados no
petróleo como
ocorrência natural, associados ao processo de formação.
Embora presentes apenas
em quantidades pequenas (níveis de microgramag−1 ou ng g−1), sua
determinação é de
grande importância, devido seu alto potencial de
contaminação do meio ambiente
e de interferência durante o processo de refino. Estes
elementos podem causar
corrosão nas torres de refino, envenenar catalisadores e/ou
causar reações
secundárias indesejáveis nas operações de refino. Além
disso, os metais pesados,
quando presentes nos derivados de petróleo, são
relacionados ao seu mau
desempenho, redução da sua estabilidade térmica por
catalisar reações oxidativas
e, no caso da nafta, interferência nos processos
petroquímicos. Os riscos
ambientais dependem da toxidade e da concentração de cada
elemento, bem como
a interferência no refino depende do metal e de sua
concentração. Assim, foram
estudados procedimentos rápidos, simples, exatos e precisos
para a determinação
de elementos traço em petróleo e alguns derivados pela
espectrometria de
absorção atômica com forno de grafite. Para amostras de
diesel, gasolina e nafta,
são propostos procedimentos para a determinação de As e Mn
em nível de ng
mL−1. A estabilização das amostras foi necessária e obtida
pela formação de
sistemas de três componentes, preparadas pela mistura de
volumes adequados da
amostra, do propan-1-ol e da solução aquosa de HNO3,
resultando em um meio
unifásico, indefinidamente estável. A utilização de
modificação de matriz foi
investigada. A otimização multivariada definiu a composição
ótima da
microemulsão, bem como o programa de temperatura. Os
limites de detecção nas
amostras originais para As foram 1,8, 1,2 e 1,5 ng mL−1 e
para Mn foram 0,6, 0,5
e 0,3 ng mL−1 para diesel, gasolina e nafta,
respectivamente. A exatidão dos métodos foi confirmada por
testes de recuperação e por análise de um conjunto de
amostras comerciais por procedimentos comparativos
independentes. Para
amostras de petróleo, são propostos procedimentos para a
determinação direta de
Ni, Cu, Fe e V, usando um acessório de amostragem de
sólidos, sem qualquer prétratamento
da amostra. Uma solução de Pd + Triton X-100 foi utilizada
como
modificador químico. As temperaturas de pirólise e
atomização, bem como a
massa do Pd foram definidas por otimização multivariada. Os
limites de detecção
nas condições otimizadas foram 230, 10, 200 e 800 pg de Ni,
Cu, Fe e V,
respectivamente. A exatidão dos métodos foi confirmada pela
análise de materiais
de referência certificados de petróleo, bem como por
comparação com métodos
independentes. Para todos os procedimentos propostos, a
calibração com solução
analítica aquosa foi possível. / [en] Petroleum is a complex mixture of hydrocarbons (50 to 95 percent)
and nonhydrocarbons
(mainly S, N, O and heavy metal compounds). Metallic traces
are
normally found in petroleum as naturally occurring elements
associated to the
formation process. Although present only in small amounts
(Microgram −1 or ng g−1
levels), their determination is of great interest because
of their high potential of
environmental contamination and interference in the
refining process. They may
corrode refinery equipment, poison and foul catalysts
and/or cause undesirable
side reactions in refinery operations. Moreover, heavy
metals present in petroleum
derivates such as diesel, gasoline and naphtha are related
to poor performance and
reduction of their thermal stability. Thus, fast, simple
and reliable procedures for
the determination of trace metals in petroleum and its
derivates by graphite
furnace atomic absorption spectrometry were studied. For
diesel, gasoline and
naphtha samples, procedures for the determination of As and
Mn (ng mL−1 levels)
are proposed. Sample stabilization was necessary and
achieved by the formation
of three component system prepared by mixing appropriate
volumes of the
samples, propan-1-ol and nitric acid aqueous solution,
resulting in a one-phase
medium indefinitely stable (microemulsion). The use of
matrix modification was
also investigated. Multivariate optimization defined the
optimum microemulsion
composition as well as the temperature program. The limits
of detection in the
original samples for As were 1.8, 1.2 and 1.5 ng ml−1 while
for Mn they were 0.6,
0.5 and 0.3 ng mL-1 for diesel, gasoline and naphtha,
respectively. Methods
accuracies were confirmed by recoveries tests and the
analysis of a set of
commercial samples by the proposed and independent
comparative procedures.
For petroleum samples, procedures for the direct
determination of Ni, Cu, Fe and
V using a solid sampling accessory, without any sample pre-
treatment, are
proposed. A Pd+Triton X-100 solution was used as chemical
modifier. The pyrolysis and atomization temperatures, as
well as the Pd
mass were defined by
multivariate optimization. The limits of detection at the
optimized conditions were
230, 10, 200 and 800 pg for Ni, Cu, Fe and V, respectively.
Methods` accuracies
were confirmed by the analysis of oil certified reference
materials as well as by
comparison with independent methods. For all proposed
procedures, calibration
using aqueous analytical solutions was possible.
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Criação e desvio de comércio no Mercosul e no Nafta / Trade creation and trade diversion in Mercosur and NaftaMorais, Adriano Giacomini 01 November 2005 (has links)
A integração comercial entre países vem ocorrendo através de negociações multilaterais e acordos regionais. As teorias de comércio internacional dizem que as primeiras provocam aumento de bem-estar. Entretanto, não há consenso sobre os efeitos dos segundos. O papel deste trabalho é justamente avaliar os impactos de dois acordos comerciais, o Mercosul e o Nafta, sobre dois critérios de bem-estar, a criação e o desvio de comércio. Isso é feito através da estimação de equações gravitacionais para dados em painel, com a inclusão de variáveis dummy para captar a relação intra e extra-bloco, conforme metodologia apresentada por Endoh (1999). Os resultados apontaram que não ocorreu criação de comércio em ambos os acordos. O Nafta foi seguido por desvio de comércio e o Mercosul apresentou dificuldades na mensuração do mesmo. / The commercial integration between countries has been taking place through multilateral negotiations and regional agreements. Economic theories of international trade say that the first one improves welfare. However, there is no consensus about the second one. The aim of this dissertation is just to evaluate the effects of two agreements, Mercosur and Nafta, on two concepts of welfare, trade creation and trade diversion. This is done through the estimation of gravity equations by panel data methods, with dummy variables to detect intra-bloc and extra-bloc relations, according to the methodology of Endoh (1999). The results suggested that trade creation has not occurred in both agreements. Nafta was followed by trade diversion and Mercosur presented difficulties in measuring this component.
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Criação e desvio de comércio no Mercosul e no Nafta / Trade creation and trade diversion in Mercosur and NaftaAdriano Giacomini Morais 01 November 2005 (has links)
A integração comercial entre países vem ocorrendo através de negociações multilaterais e acordos regionais. As teorias de comércio internacional dizem que as primeiras provocam aumento de bem-estar. Entretanto, não há consenso sobre os efeitos dos segundos. O papel deste trabalho é justamente avaliar os impactos de dois acordos comerciais, o Mercosul e o Nafta, sobre dois critérios de bem-estar, a criação e o desvio de comércio. Isso é feito através da estimação de equações gravitacionais para dados em painel, com a inclusão de variáveis dummy para captar a relação intra e extra-bloco, conforme metodologia apresentada por Endoh (1999). Os resultados apontaram que não ocorreu criação de comércio em ambos os acordos. O Nafta foi seguido por desvio de comércio e o Mercosul apresentou dificuldades na mensuração do mesmo. / The commercial integration between countries has been taking place through multilateral negotiations and regional agreements. Economic theories of international trade say that the first one improves welfare. However, there is no consensus about the second one. The aim of this dissertation is just to evaluate the effects of two agreements, Mercosur and Nafta, on two concepts of welfare, trade creation and trade diversion. This is done through the estimation of gravity equations by panel data methods, with dummy variables to detect intra-bloc and extra-bloc relations, according to the methodology of Endoh (1999). The results suggested that trade creation has not occurred in both agreements. Nafta was followed by trade diversion and Mercosur presented difficulties in measuring this component.
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Naftos kainų pokyčiai ir jų įtaka ekonomikai / Oil price developments and their influence to economyPranskūnas, Vaidotas 21 June 2010 (has links)
Šio magistro baigiamojo darbo tikslas – išanalizuoti naftos kainų kitimą ir kitimo įtaką ekonomikai. Pirmojoje darbo dalyje aptariama naftos kainų kaitos istoriniai kitimo aspektai, pateikiami autorių naftos kainų kitimo traktavimo ypatumai, apžvelgiami svarbiausi naftos paklausos ir pasiūlos veiksniai, įrodoma naftos kainų kitimo svarba bei išsamiai išanalizuojami prognozavimo modeliai. Antrojoje dalyje atliekama išsami naftos kainos kitimo poveikio globaliai rinkai analizė, naftos kainų kitimo įtakai ekonominiam augimui apskaičiuoti naudojama regresinė analizė. Trečiojoje dalyje pateikiamos naftos kainų kitimo ateityje perspektyvos, naudojantis prognozavimo agentūrų ateities tendencijomis, sukuriamas trijų scenarijų naftos kainos kitimo modelis. Atliktas tyrimas parodė, kad naftos kainos kitimas priklauso nuo labai daug skirtingų kintamųjų, kitimas turi didelę reikšmę makroekonominiams procesams, tarp jų ir ekonominiam augimui. Tad labai svarbu ištirti naftos kainų kitimo priežastis. Buvo apžvelgta ir įvertinta plati naftos kainų kitimo ir numatymo bei jų poveikio literatūros analizė. Regresine analize buvo nustatyta naftos kainų kitimo ir ekonominio augimo sąveika. Buvo pateikti ateities naftos kainos kititmo ypatumai, sukurti trys ateities naftos kainos kitimo scenarijai. / This master thesis aim – to analyze the dynamics of oil prices and oil price changes effects on the economy. The first part deals with oil price changes in the historical aspects of the change, the authors’ opininion on oil price changes are revealed, most important oil supply and demand factors are revealed, as evidenced by oil price developments and the importance of forecasting models are analyzed in detail. The second part consists of rigorous impact of oil price movements of global market analysis, to calculate oil price changes impact on the economic grwth, regression analysis is used. The third part presents the changes in oil prices in the future prospects of using future trends forecasting agencies, created three scenarios of oil price changes in the model. An investigation showed that the price of oil varies from a very range of variables, changes have significant variation in the macroeconomic process, including economc growth. So it is important to investigate the reasons for variation in oil prices. It has been reviewed and evaluated a wide variation in oil prices and anticipation of their impact on literary analysis. Regression analysis was the change in oil prices and economic growth interface. It was the future of oil prices changes features to create three future scenarios of oil price movements.
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The Impact of the U.S. and Mexican Monetary Policy on Mexican GDP and PricesRodríguez Hernández, Lorenzo January 2015 (has links)
No description available.
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Preferential Trade Agreements and Globalization: The Impact of a Common FoundationRothe, Holly M January 2004 (has links)
Thesis advisor: Robert Murphy / Given the increasing proliferation of preferential trade agreements, this work seeks to investigate the economic, political, and cultural relationships that may be built from the common foundation of a trade agreement. It evaluates the experiences of the European Union and the North American Free Trade Agreement and makes predictions and suggestions for future preferential trading partners, as well as analyzing the potential impact that PTAs will have on globalization and international relations. / Thesis (BA) — Boston College, 2004. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: International Studies. / Discipline: College Honors Program.
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O conflito de jurisdição entre sistemas de soluções de controvérsias multilateral e regionalSantos, Ruth Maria Pereira dos January 2013 (has links)
Submitted by Haia Cristina Rebouças de Almeida (haia.almeida@uniceub.br) on 2015-03-05T17:43:50Z
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61100076.pdf: 957663 bytes, checksum: 4abb255d7310b6713af2913df034df4f (MD5) / Made available in DSpace on 2015-03-05T17:43:50Z (GMT). No. of bitstreams: 1
61100076.pdf: 957663 bytes, checksum: 4abb255d7310b6713af2913df034df4f (MD5) / Este trabalho visa a analisar os conflitos de jurisdição existentes entre os sistemas
de solução de controvérsias regional e multilateral. Primeiramente se faz o cotejo da
evolução dos dois sistemas de comércio internacional, de modo a comprovar que
ambos partem de uma mesma vertente, não sendo contraditórios, podendo atuar
conjuntamente, uma vez que não há hierarquia entre a Organização Mundial do
Comércio (OMC) e os Acordos Regionais. Contudo, há uma ausência de normas
que discipline a relação entre os mecanismos de resolução de litígio. Para tanto,
trata-se de mecanismos existentes no Direito Público, a fim de verificar a
aplicabilidade no Direito Internacional Econômico, tais como os institutos oriundos da
Teoria Geral do Processo, a conexão, a litispendência e a coisa julgada. Além das
cláusulas de eleição de foro que estão inseridas em alguns textos normativos dos
acordos regionais, bem como, os princípios do foro non conveniens e foro
conveniens. Assim, descreve-se o posicionamento da jurisprudência da OMC e
atuação dos mecanismos regionais em dois casos em que houve conflito de
jurisdição entre a OMC e os blocos regionais (NAFTA e MERCOSUL).
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Separation of light naphtha for the octane upgrading of gasoline : adsorption and membrane technologies and new adsorbentsBárcia, Patrick da Silva January 2010 (has links)
Tese de doutoramento. Engenharia Química e Biológica. Faculdade de Engenharia. Universidade do Porto. 2010
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Mexican refugees in Canada post-NAFTA and the effects of immigration and refugee policy reforms: 1994-2012Hashman, Emma Therese 01 May 2013 (has links)
Canada and Mexican relations have not been written about in much length past Canada's Temporary Foreign Worker Program (TFWP) recruiting Mexican laborers. In recent years, migration from Mexico to Canada has increased at an exponential rate. The most significant and notable increase has been in the number of refugee claims from Mexicans wanting to seek asylum in Canada. It is found that Canada is the number one destination for Mexican refugees, while Canada accepts their claims at an alarmingly low rate compared to claims from other nations, even in Latin America. I argue the reason Mexicans chose Canada to claim refugee status is Canada's long history of an open immigration policy and especially their economic and temporary labor agreements with Canada. These policies give the impression to Mexicans they are very much welcome in Canada. This is proved to be untrue when Canada changed their immigration and refugee policies in response, specifically, to the overwhelming number of Mexican refugee claims.
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The Effect of Neoliberalism on Capabilities: Evaluating the Case of MexicoWalker, James Paul 20 October 2015 (has links)
The goal of this thesis is to examine the effect of neoliberalism on developing nations. Specifically it will look at how neoliberalism has affected Mexico via the North American Free Trade Agreement. Mexico was chosen because since its depression in 1982 it has adopted continuing neoliberal policy, which according to its leaders, United States leaders, and international governmental bodies, is the path to development and the improvement of the standard of living for all people. This work begins by examining the historical path of neoliberalism to provide context for choosing Mexico for the focal point of this thesis, as well as context for the situation occurring in Mexico. It then examines neoliberalism via its scholars who are in support of it and against it. This is followed by an evaluation method based off of Amarya Sen's capability approach to development. Then several previous studies are examined to prove qualitatively that there have been adverse effects experienced under NAFTA in Mexico, by all of the established evaluation parameters. Then this thesis turns to a discussion of some descriptive statistics relating to the approach set up by Sen. It concludes with quantitative approach showing over interesting correlations of neoliberalism, to other variables indicative of capabilities via linear regression.
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