SiO(2) in density functional theory and beyond

We present the first-principle electronic structure calculation on an amorphous material including many-body corrections within the GW approximation. We show that the inclusion of the local field effects in the exchange-correlation potential is crucial to quantitatively describe amorphous systems and defect states. We show that the mobility gap of amorphous silica coincides with the band gap of quartz, contrary to the traditional picture and the densityfunctional theory results. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Recoverable rhodium nanoparticles: Synthesis, characterization and catalytic performance in hydrogenation reactions

We here report the first magnetically recoverable Rh(0) nanoparticle-supported catalyst with extraordinary recovery and recycling properties. Magnetic separation has been suggested as a very promising technique to improve recovery of metal-based catalysts in liquid-phase batch reactions. The separation method is significantly simple, as it does not require filtration, decantation, centrifugation, or any other separation technique thereby, overcoming traditional time- and solvent-consuming procedures. Our new magnetically separable catalytic system, comprised of Rh nanoparticles immobilized on silica-coated magnetite nanoparticles, is highly active and could be reused for up to 20 times for hydrogenation of cyclohexene (180,000 mol/mol(Rh)) and benzene (11,550 mol/mol(Rh) under mild conditions. (c) 2007 Elsevier B. V. All fights reserved.

FAST, PARALLEL AND SECURE CRYPTOGRAPHY ALGORITHM USING LORENZ`S ATTRACTOR

A novel cryptography method based on the Lorenz`s attractor chaotic system is presented. The proposed algorithm is secure and fast, making it practical for general use. We introduce the chaotic operation mode, which provides an interaction among the password, message and a chaotic system. It ensures that the algorithm yields a secure codification, even if the nature of the chaotic system is known. The algorithm has been implemented in two versions: one sequential and slow and the other, parallel and fast. Our algorithm assures the integrity of the ciphertext (we know if it has been altered, which is not assured by traditional algorithms) and consequently its authenticity. Numerical experiments are presented, discussed and show the behavior of the method in terms of security and performance. The fast version of the algorithm has a performance comparable to AES, a popular cryptography program used commercially nowadays, but it is more secure, which makes it immediately suitable for general purpose cryptography applications. An internet page has been set up, which enables the readers to test the algorithm and also to try to break into the cipher.

On Aspects of Mathematical Reasoning : Affect and Gender

This thesis explores two aspects of mathematical reasoning: affect and gender. I started by looking at the reasoning of upper secondary students when solving tasks. This work revealed that when not guided by an interviewer, algorithmic reasoning, based on memorising algorithms which may or may not be appropriate for the task, was predominant in the students reasoning. Given this lack of mathematical grounding in students reasoning I looked in a second study at what grounds they had for different strategy choices and conclusions. This qualitative study suggested that beliefs about safety, expectation and motivation were important in the central decisions made during task solving.  But are reasoning and beliefs gendered? The third study explored upper secondary school teachers conceptions about gender and students mathematical reasoning. In this study I found that upper secondary school teachers attributed gender symbols including insecurity, use of standard methods and imitative reasoning to girls and symbols such as multiple strategies especially on the calculator, guessing and chance-taking were assigned to boys. In the fourth and final study I found that students, both male and female, shared their teachers view of rather traditional feminities and masculinities. Remarkably however, this result did not repeat itself when students were asked to reflect on their own behaviour: there were some discrepancies between the traits the students ascribed as gender different and the traits they ascribed to themselves. Taken together the thesis suggests that, contrary to conceptions, girls and boys share many of the same core beliefs about mathematics, but much work is still needed if we should create learning environments that provide better opportunities for students to develop beliefs that guide them towards well-grounded mathematical reasoning. 

The Music Salon in Falun During the 19th Century

The aim of the project is to examine the music salon in Falun as a part of the mining community and in the historical context of European salon culture. A specifc goal is to develop a deeper understanding about the salon when it comes to education and pedagogic ideas. Of a certain interest is Johan Henrik Munktell’s (1804-1861) education travelling (bildningsresor). Inspired by Mendelssohn’s music salon in Berlin and the early salons in Upp-sala he created his own salon in Grycksbo. A letter collection from J.H. Munktell to his father J.J. Munktell in 1828-30 can be considered a unique historical material, which places the salon in Falun in a continental context of culture, education and industrial pretensions. The results have potential to extend the knowledge of Nordic salon culture and how it has infuenced general pedagogy and music education.

Intent and Method: A Study of Female Characters in Aeschylean and Euripidean Drama

Aeschylus and Euripides used tragic female characters to help fulfill the purpose of religious celebration and to achieve the motivation of public reaction. The playwrights, revising myths about tragic woman and redefining the Greek definition of appropriate femininity, supported or questioned the very customs which they changed. Originally composed as part of a religious festival for Dionysus, the god of wine, revelry and fertility, the tragedies of Aeschylus and Euripides were evaluated by Aristotle. He favored Aeschylus over Euripides, but it appears as if his stipulations for tragic characterization do not apply to Aeschylean and Euripidean women. Modem critics question both Aristotle's analysis in the Poetics as well as the tragedies which he evaluated. As part of the assessment of Aeschylus, the character of the Persian Queen, Atossa, appears as a conradiction the images that Greeks maintain of non-Greeks. The Persians is discussed in relation to modem criticisms and as on its function as a warning against radical changes in Athenian domestic life. The Oresteia, a trilogy, also charts the importance of an atypical woman in Aeschylean tragedy, and how this role, Clytaemnestra, represents an extreme example of the natural and necessary evolution of families, households and kingdoms. In contrast to Aeschylus' plea to retain nomoi (traditional custom and law), EUripides' tragedy, the Medea, demonstrates the importance of a family and a country to provide security, especially for women. Medea's abandonment by Jason and subsequent desperation drives her to commit murder in the hope of revenge. Ultimately, Euripides advocates changes in social convention away from the alienation of non-Greek, non-citizens, and females. Euripides is, unfortunately, tagged a misogynist by some in this tragedy and another example-the Hippolytus. Euripides' Phaedra becomes entangled in a scheme of divine vengeance and ultimately commits suicide in an attempt to avoid societal shame. Far from treatises of hate, Euripidean women take advantage of the little power they possess within a constrictive social system. While both Aeschylus and Euripides revise customary images and expectations of women in the context of religiously-motivated drama, one playwright intends to maintain civic order and the other intends to challenge the secular norm.

Budgeting and resource allocation in universities, a public choice approach

The calls urging colleges and universities to improve their productivity are coming thick and fast in Brazil. Many studies are suggesting evaluation systems and external criteria to control universities production in qualitative terms. Since universities and colleges are not profit-oriented organizations (considering just the fair and serious researching and teaching organizations, of course) the traditional microeconomics and administrative variables used to measure efficiency do not have any direct function. In this sense, It could be created a as if market control system to evaluate universities and colleges production. The budget and the allocation resources mechanism inside it can be used as an incentive instrument to improve quality and productivity. It will be the main issue of this paper.

Model selection, estimation and forecasting in VAR models with short-run and long-run restrictions

We study the joint determination of the lag length, the dimension of the cointegrating space and the rank of the matrix of short-run parameters of a vector autoregressive (VAR) model using model selection criteria. We consider model selection criteria which have data-dependent penalties for a lack of parsimony, as well as the traditional ones. We suggest a new procedure which is a hybrid of traditional criteria and criteria with data-dependant penalties. In order to compute the fit of each model, we propose an iterative procedure to compute the maximum likelihood estimates of parameters of a VAR model with short-run and long-run restrictions. Our Monte Carlo simulations measure the improvements in forecasting accuracy that can arise from the joint determination of lag-length and rank, relative to the commonly used procedure of selecting the lag-length only and then testing for cointegration.

Model selection, estimation and forecasting in VAR models with short-run and long-run restrictions

We study the joint determination of the lag length, the dimension of the cointegrating space and the rank of the matrix of short-run parameters of a vector autoregressive (VAR) model using model selection criteria. We consider model selection criteria which have data-dependent penalties as well as the traditional ones. We suggest a new two-step model selection procedure which is a hybrid of traditional criteria and criteria with data-dependant penalties and we prove its consistency. Our Monte Carlo simulations measure the improvements in forecasting accuracy that can arise from the joint determination of lag-length and rank using our proposed procedure, relative to an unrestricted VAR or a cointegrated VAR estimated by the commonly used procedure of selecting the lag-length only and then testing for cointegration. Two empirical applications forecasting Brazilian inflation and U.S. macroeconomic aggregates growth rates respectively show the usefulness of the model-selection strategy proposed here. The gains in different measures of forecasting accuracy are substantial, especially for short horizons.

Model selection, estimation and forecasting in VAR models with short-run and long-run restrictions

We study the joint determination of the lag length, the dimension of the cointegrating space and the rank of the matrix of short-run parameters of a vector autoregressive (VAR) model using model selection criteria. We consider model selection criteria which have data-dependent penalties as well as the traditional ones. We suggest a new two-step model selection procedure which is a hybrid of traditional criteria and criteria with data-dependant penalties and we prove its consistency. Our Monte Carlo simulations measure the improvements in forecasting accuracy that can arise from the joint determination of lag-length and rank using our proposed procedure, relative to an unrestricted VAR or a cointegrated VAR estimated by the commonly used procedure of selecting the lag-length only and then testing for cointegration. Two empirical applications forecasting Brazilian in ation and U.S. macroeconomic aggregates growth rates respectively show the usefulness of the model-selection strategy proposed here. The gains in di¤erent measures of forecasting accuracy are substantial, especially for short horizons.

Model selection, estimation and forecasting in VAR models with short-run and long-run restrictions

We study the joint determination of the lag length, the dimension of the cointegrating space and the rank of the matrix of short-run parameters of a vector autoregressive (VAR) model using model selection criteria. We suggest a new two-step model selection procedure which is a hybrid of traditional criteria and criteria with data-dependant penalties and we prove its consistency. A Monte Carlo study explores the finite sample performance of this procedure and evaluates the forecasting accuracy of models selected by this procedure. Two empirical applications confirm the usefulness of the model selection procedure proposed here for forecasting.

Desenhando um paraíso tropical: a construção do Rio de Janeiro como um destino turístico

As primeiras imagens (gráficas ou narrativas) que circularam no exterior sobre o Rio de Janeiro. O complexo processo de produção em série da imagem, envolvendo vários profissionais que muitas vezes trabalhavam a distância. As possibilidades econômicas de uma cidade a ser construída, e o interesse de imigrantes aventureiros e empreendedores. A cidade que os primeiros guias para viajantes pretendiam mostrar. A modernização da urbe, voltada para o olhar internacional. A construção da identidade nacional pela música, dança e a indústria do entretenimento. A identificação do carioca com os estereótipos que lhe foram concedidos.A perpetuação dos ícones da cidade. Este trabalho perpassa várias categorias temáticas, buscando revelar o processo de construção da cidade do Rio de Janeiro enquanto um destino turístico. Um paraíso tropical a ser conhecido.

Product placement in movies: a cross cultural study between Brazil and the USA

The broader objective of this study undertaking can briefly be articulated in particulate aims as follows: to measure the attitudes of consumers regarding the brand displayed by this strategy as well as to highlight recall, recognition and purchase intentions generated by product placement on consumers. In addition, check the differences and similarities between the behavior of Brazilian and American consumers caused by the influence of product placements. The study was undertaken targeting consumer audience in Brazil and the U.S. A rang3 modeling set ups were performed in order to realign study instruments and hypothesis towards the research objectives. This study gave focus on the following hypothesized models. H1: Consumers / Participants who viewed the brands / products in the movie have a higher brand / product recall compared to the consumers / participants who did not view the brands / products in the movie. H2: US Consumers / Participants are able to recognize and recall brands / products which appear in the background of the movie than Brazil. H3: Consumers / participants from USA are more accepting of product placements compared to their counterparts in Brazil. H4: There are discernible similarities in consumer / participant brand attitudes and purchase intentions in consumers / participants from USA and Brazil in spite of the fact that their country of origin is different. Cronbach’s Alpha Coefficient ensured the reliability of survey instruments. The study involved the use of the Structural Equation Modeling (SEM) for the hypothesis testing. This study used the Confirmatory Factor Analysis (CFA) to assess both the convergent and discriminant validities instead of using the Exploratory Factor Analysis (EFA) or the Principal Component Analysis (PCA). This reinforced for the use of the regression Chi Square and T statistical tests in further. Only hypothesis H3 was rejected, the rest were not. T test provided insight findings on specific subgroup significant differences. In the SEM testing, the error variance for product placement attitudes was negative for both the groups. On this The Heywood Case came in handy to fix negative values. The researcher used both quantitative and qualitative approach where closed ended questionnaires and interviews respectively were used to collect primary data. The results were additionally provided with tabulations. It can be concluded that, product placement varies markedly in the U.S. from Brazil based on the influence a range of factors provided in the study. However, there are elements of convergence probably driven by the convergence in technology. In order, product placement to become more competitive in the promotional marketing, there will be the need for researchers to extend focus from the traditional variables and add knowledge on the conventional marketplace factors that is the sell-ability of the product placement technologies and strategies.

Batidas intensas : corpo e sociabilidade nas festas de música eletrônica em Natal

The significance of the body in electronic music parties as a sign for communicating and socializing among participants is the focus of this work. Qualitative research undertaken in this study seeks to investigate how sociability happens at raves and nightclubs in Natal/RN. Sociability is understood here as a play expression involving the dimensions of music, dance and party; the body, seen from a transdisciplinary approach, is understood as a symbolic instance, with its own meanings, as a result and a producer of social and as a cross between the cultural and the biological. The body has a communicative potential, is primary media. An intersection point between nature and culture, it serves as the seat of emotions and sociability, since it is through it that social relations are made. In electronic music parties, the body is interpreted based on its communication signs: clothing, accessories, body movements, tactile contact, body language, interactions between the public and dj, the dj and the public, gestures, expressive speech of emotions. Through such signs, body communication and a sense of community among participants develop sociability in the festive place and change the mood of the dancers. The Natal s electronic music parties young goer interacts on parties, adopts cheerful and receptive positions towards the other, maintains physical contact, values dance as a form of communication and lists happiness as the main feeling aroused in electronic music festivals. To achieve this result, a plurimetodological approach was used, which consisted of various methodological devices and various techniques of investigation: ethnographic observation, individual and informal interview techniques, photographic record of the scene, in-depth interview and application thirty questionnaires to patrons of electronic music parties