A yield curve model with macroeconomic and financial variables

This thesis has the goal to fit the Portuguese yield curve constructing a model with not only latent factors, but also macroeconomic factors, such as inflation, marginal lending rate and industrial production. The model will incorporate the Nelson and Siegel (1987) decomposition and it will be made using a state-space framework, where the estimation results gave me a good fitting of the yield curve. Afterwards, I analyze the correlation between the yield curve components and the macroeconomic variables by impulse response functions and variance decompositions, where I find a causality relationship between macro variables and the latent factors

Effect of compressive deformations on the final microstructure of a low carbon high silicon bainitic steel thermomechanically processed

Due to a combination of advantages, high-performance steel components, especially for automotive manufacturing applications, are generally forged parts. In the forging industry, bainitic steels are being increasingly used, because they can reduce the processing chain and energy consumption. In this case, the bainitic microstructure can be obtained immediately after forging, with controlled cooling, and without any subsequent heat treatment. In the present work, the effect of thermomechanical routes performed in the austenitic and bainitic fields on the final microstructure and final hardness of 18MnCrSiMo6-4 bainitic steel has been discussed. Thermomechanical processing routes were tested and evaluated in a Gleeble® 3800 testing machine with one and two-step deformation. In both cases, the sample had its height reduced by 40% and the strain rate used was 0.1s-1. It could be shown that the plastic deformation promoted in the bainite field induces the bainite transformation. The results also show a strong dependence of bainite morphology concerning the deformation temperature of the steel. Moreover, the knowledge of the hot and warm stress-strain curves is an important result because it allows estimating the necessary stress and the energy consumption per volume unit to deform the material

Recovery of silver residues from dental amalgam

Dental amalgam residues are probably the most important chemical residues generated from clinical dental practice because of the presence of heavy metals among its constituents, mainly mercury and silver. OBJECTIVE: The purpose of this study was to develop an alternative method for the recovery of silver residues from dental amalgam. MATERIAL AND METHODS: The residue generated after vacuum distillation of dental amalgam for the separation of mercury was initially diluted with 32.5% HNO3, followed by precipitation with 20% NaCl. Sequentially, under constant heating and agitation with NaOH and sucrose, the sample was reduced to metallic silver. However, the processing time was too long, which turned this procedure not viable. In another sequence of experiments, the dilution was accomplished with concentrated HNO3 at 90ºC, followed by precipitation with 20% NaCl. After washing, the pellet was diluted with concentrated NH4OH, water and more NaCl in order to facilitate the reaction with the reducer. RESULTS: Ascorbic acid was efficiently used as reducer, allowing a fast reduction, thus making the procedure viable. CONCLUSIONS: The proposed methodology is of easy application and does not require sophisticated equipment or expensive reagents.FAPESPODONTOPRE

Pulmonary metastasectomy from soft tissue sarcomas

INTRODUCTION: Isolated pulmonary metastases from soft tissue sarcomas occur in 20-50% of these(the issue is about metastases, not lung cancer )patients, and 70% of these patients will present disease limited only to the lungs. Surgical resection is well accepted as a standard approach to treat metastases from soft tissue sarcomas isolated in the lungs, and many studies investigating this technique have reported an overall 5-year survival ranging from 30-40%. The most consistent predictor of survival in these patients is complete resection. The aim of the present study was to determine the demographics and clinical treatment-related variables associated with long-term (90-month) overall survival in patients with lung metastases undergoing pulmonary metastasectomy from soft tissue sarcomas. METHODS: We performed a retrospective review of patients admitted in the Thoracic Surgery Department with lung metastases who underwent thoracotomy for resection following treatment of the primary tumor. Data regarding primary tumor features, demographics, treatment, and outcome were collected. RESULTS: One hundred twenty-two thoracotomies and 273 nodules were resected from 77 patients with previously treated soft tissue sarcomas. The median follow-up time of all patients was 36.7 months (range: 10-138 months). The postoperative complication rate was 9.1%, and the 30-day mortality rate was 0%. The 90-month overall survival rate for all patients was 34.7%. Multivariate analysis identified the following independent prognostic factors for overall survival: the number of metastases resected, the disease-free interval, and the number of complete resections. CONCLUSION: These results confirm that lung metastasectomy is a safe and potentially curative procedure for patients with treated primary tumors. A select group of patients can achieve long-term survival after lung resection

Estratégia e desempenho de plataformas audiovisuais de streaming

Purpose: This work aims to analyze and classify the competitive strategies of 37 streaming platforms and identify which strategic groups perform better globally. Design/methodology/approach: This study is based on the structure-conduct-performance paradigm and uses Porter's typology to reach its goal. It classified the 37 platforms into their respective strategic groups based on eight strategic variables using k-means cluster analysis. Then, group performances were compared using ANOVA to test the mean differences of two performance variables. Originality/relevance: The audiovisual industry is experiencing a radical change in content consumption, distribution, and production. Streaming technology, which delivers content over the internet without downloads, increased flexibility and sparked a wave of adoption of audiovisual streaming platforms that destabilized other sectors, such as home video. Consequently, this phenomenon left a gap in studies about the strategy and performance of the industry, which this paper intends to fill. Main findings: As a result, 14% of the platforms studied were allocated to the Differentiation strategic group, 30% to Cost Leadership, 19% to Differentiation Focus, 8% to Cost Focus, and 30% were considered Stuck-In-The-Middle. We identified that the strategic groups present significant differences in performance, validating the applicability of Porter's typology. Theoretical contributions: The study found that broad-spectrum strategies such as Cost Leadership and Differentiation promote better performance than focus strategies at this industry stage. Surprisingly, Stuck-In-The-Middle companies also perform well, similar to companies with broad-spectrum strategies.Propósito: Este trabajo tiene como objetivo analizar y clasificar las estrategias competitivas de 37 plataformas de streaming e identificar qué grupos estratégicos se desempeñan mejor a nivel global. Diseño/metodología/enfoque: Este estudio se basa en el paradigma estructura-conducta-desempeño y utiliza la tipología de Porter para lograr su objetivo. Clasificó las 37 plataformas en sus respectivos grupos estratégicos en función de ocho variables estratégicas utilizando un análisis de conglomerados de k-medias. Luego, se compararon los desempeños grupales utilizando ANOVA para probar las diferencias medias de dos variables de desempeño. Originalidad/relevancia: La industria audiovisual está experimentando un cambio radical en el consumo, distribución y producción de contenidos. La tecnología de streaming, que ofrece contenidos a través de Internet sin descargas, aumentó la flexibilidad y provocó una ola de adopción de plataformas de streaming audiovisual que desestabilizó otros sectores, como el del vídeo doméstico. En consecuencia, este fenómeno dejó un vacío en los estudios sobre la estrategia y el desempeño de la industria, que este artículo pretende llenar. Principales hallazgos: Como resultado, el 14% de las plataformas estudiadas se asignaron al grupo estratégico de Diferenciación, el 30% al Liderazgo en Costos, el 19% al Enfoque en Diferenciación, el 8% al Enfoque en Costos y el 30% se consideraron ‘Stuck-in-the-middle’. Identificamos que los grupos estratégicos presentan diferencias significativas en su desempeño, validando la aplicabilidad de la tipología de Porter. Contribuciones teóricas: El estudio encontró que las estrategias de amplio espectro como el liderazgo en costos y la diferenciación promueven un mejor desempeño que las estrategias de enfoque en esta etapa de la industria. Sorprendentemente, las empresas ‘Stuck-in-the-middle’ también obtienen buenos resultados, al igual que las empresas con estrategias de amplio espectro.Objetivo: Este artigo analisa e classifica as estratégias de 37 plataformas de streaming, identificando quais grupos estratégicos mostram melhor desempenho global. Concepção/metodologia/abordagem: Este estudo se baseia no paradigma estrutura-conduta-desempenho, e utiliza a tipologia de Porter para alcançar seu objetivo. Classificamos as 37 plataformas em seus respectivos grupos estratégicos, com base em oito variáveis estratégicas, utilizando a análise de cluster K-means. Em seguida, os desempenhos dos grupos foram comparados utilizando ANOVA, para testar as diferenças de médias de duas variáveis de desempenho. Originalidade/relevância: A indústria audiovisual está passando por uma mudança radical no consumo, distribuição e produção de conteúdo. A tecnologia de streaming, que fornece conteúdo pela Internet sem a necessidade de download, aumentou a flexibilidade e provocou uma onda de adoção de várias plataformas de streaming audiovisual, desestabilizando outros setores, como o de home video. Consequentemente, esse fenômeno abriu uma lacuna nos estudos sobre estratégia e desempenho do setor, que este artigo visa preencher. Principais resultados: 14% das plataformas estudadas enquadram-se no grupo estratégico de Diferenciação, 30% em Liderança em Custo, 19% em Foco em Diferenciação, 8% em Foco em Custo, e 30% foram consideradas Stuck-in-the-Middle. Os grupos estratégicos apresentaram diferenças significativas de desempenho, validando, assim, a aplicação da tipologia de Porter. Contribuição Teórica: O estudo mostra que estratégias de amplo espectro, como Liderança em Custo e Diferenciação, obtiveram melhor desempenho do que estratégias de foco neste setor. Surpreendentemente, as empresas Stuck-in-the-Middle também tiveram bom desempenho, semelhante ao das empresas com estratégias de amplo escopo

Surface processing to improve the fatigue strength of bainitic steels : an overview

Currently, one of the major challenges for automotive industries is to reduce the weight and energy consumption of vehicles by using stronger and advanced low-cost materials. Conventional solutions using quenched and tempered steels not always fulfill the desired technical, economic and environmental requirements. Modern continuous cooling bainitic steels can provide a good combination of mechanical strength and toughness, being considered an excellent alternative to replace quenched and tempered martensitic steels in the manufacture of forged components. To meet the desired industry standards in highly loaded components, properties like surface hardness, fatigue strength, wear and friction resistance of these steels can be further improved by subsequent mechanical and thermochemical treatments. Therefore, this paper presents the state of the art in the use of continuous cooling bainitic steels for forging and low energy consumption surface improvement techniques such as: deep rolling and plasma nitriding. Finally, case studies are presented, and conclusions drawn on the current trends and reported practices. Surface modification techniques must be carefully controlled and combined with the material of interest to ensure that undesirable characteristics are not introduced during the manufacturing of the components. The development of processes based on the use of forged continuous cooling bainitic steels can be an excellent alternative to replace the conventional quenching and tempering treatment with considerable reduction of the energy consumption

Soybean-corn succession according to seeding date

O objetivo deste trabalho foi avaliar a produtividade de cultivares de soja e de milho cultivadas em sucessão, em diferentes épocas de semeadura. O experimento foi realizado em Dourados, MS, durante três safras agrícolas, nas épocas de semeadura: 15/9, 1/10, 15/10 e 1/11 para a soja; e 1/2, 15/2, 1/3 e 15/3 para o milho. Mesmo que as produtividades da soja sejam fortemente afetadas pela época de colheita, a semeadura no final de setembro e no início de outubro proporcionam maiores produtividades em longo prazo. O plantio do milho em sucessão, em meados de fevereiro, proporciona a maior produtividade de grãos na região Sul do Mato Grosso do Sul; portanto, não há necessidade de se adiantar o plantio da soja para setembro com o objetivo de garantir o plantio do milho em janeiro. A sucessão soja-milho em que a soja é semeada no início de outubro e o milho em meados de fevereiro resulta em maiores produtividades totais e reduz o risco climático associado a essas culturas na região.The objective of this work was to evaluate the grain yield of soybean and corn cultivars cropped in succession, in different sowing dates. The experiment was carried out in the municipality of Dourados, in the state of Mato Grosso do Sul, Brazil, during three growing seasons, in the sowing dates: 9/15, 10/1, 10/15, and 11/1 for soybean; and 2/1, 2/15, 3/1, and 3/15 for corn. Although soybean yields are strongly affected by the crop season, sowing between late September and early October results in higher long-term yields. Planting corn in succession in mid-February provides the highest grain yield in the southern region of the state Mato Grosso do Sul; therefore, there is no need for an early soybean sowing in September, in order to ensure corn planting in January. Soybean-corn succession in which soybean is sown in early October and corn in mid-February results in higher total grain yields and reduces the climatic risk associated with these crops in the region