Síntese do Poli (ácido láctico) por policondensação direta utilizando um planejamento fatorial

The environmental impact caused by the disposal of non-biodegradable polymer packaging on the environment, as well as the high price and scarcity of oil, caused increase of searches in the area of biodegradable polymers from renewable resources were developed. The poly (lactic acid) (PLA) is a promising polymer in the market, with a large availability of raw material for the production of its monomer, as well as good processability. The aimed of this study was synthesis PLA by direct polycondesation of lactic acid, using the tool of experimental design (DOE) (central composite rotatable design (CCRD)) to optimize the conditions of synthesis. The polymer obtained was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), viscosimetric analysis, differential scanning calorimeter (DSC) and size exclusion chromatography (SEC). The results confirmed the formation of a poly (lactic acid) semicrystalline in the syntheses performed. Through the central composite rotatable design was possible to optimize the crystallization temperature (Tc) and crystallinity degree (Xc). The crystallization temperature maximum was found for percentage of catalyst around the central point (0,3 (%W)) and values of time ranging from the central point (6h) to the upper level (+1) (8h). The crystallization temperature maximum was found for the total synthesis time of 4h (-1) and percentage of catalyst 0,1(W%) (-1). The results of size exclusion chromatography (SEC) showed higher molecular weights to 0,3 (W%) percent of catalyst and total time synthesis of 3,2h

Avaliação da cobertura e monitoramento do branqueamento de corais nos

Coral bleaching has been increasingly the focus of research around the world since the early 1980s, when it was verified to be increasing in frequency, intensity and amount of areas affected. The phenomenon has been recorded since 1993, associated with elevation of the sea surface temperature due to El Niños and water thermal anomalies, according to most reports around the world. On the coast of Rio Grande do Norte, Brazil, a mass coral bleaching event was recorded in the Environmental Protection Area of Coral Reefs (APARC) during March and April 2010, when the water temperature reached 34°C for several days. About 80% of the corals in Maracajaú reef-complex exhibited partial or total bleaching. The aims of this study were to verify representativeness of coral coverage and how the bleaching dynamic has developed among different species. Coral coverage was estimated according to Reef Check Brazil protocol associated with quadrant method, and bleaching was evaluated from biweekly visual surveys in 80 colonies of Favia gravida, Porites astreoides, Siderastrea stellata and Millepora alcicornis. At the same time temperature, pH, salinity and horizontal transparency, as well as mortality and disease occurrence were monitored. Analysis of variance and Multiple Regression from the perspective of time lag concept were used to evaluate the bleaching dynamics among species and the relationship between variation of means of bleaching and variations of abiotic parameters, respectively. Species showed significant differences among themselves as to variation of means of bleaching over time, but the dynamic of variation exhibited similar patterns

Extração enzimática de óleo e produção in situ de biodiesel a partir da Moringa oleífera Lam

With the growth and development of modern society, arises the need to search for new raw materials and new technologies which present the "clean" characteristic, and do not harm the environment, but can join the energy needs of industry and transportation. The Moringa oleifera Lam, plant originating from India, and currently present in the Brazilian Northeast, presents itself as a multi-purpose plant, can be used as a coagulant in water treatment, as a natural remedy and as a feedstock for biodiesel production. In this work, Moringa has been used as a raw material for studies on the extraction and subsequently in the synthesis of biodiesel. Studies have been conducted on various techniques of Moringa oil extraction (solvents, mechanical pressing and enzymatic), being specially developed an experimental design for the aqueous extraction with the aid of the enzyme Neutrase© 0.8 L, with the aim of analyzing the influence variable pH (5.5-7.5), temperature (45-55°C), time (16-24 hours) and amount of catalyst (2-5%) on the extraction yield. In relation to study of the synthesis of biodiesel was initially carried out a conventional transesterification (50°C, KOH as a catalyst, methanol and 60 minutes reaction). Next, a study was conducted using the technique of in situ transesterification by using an experimental design variables as temperature (30-60°C), catalyst amount (2-5%), and molar ratio oil / ethanol (1:420-1:600). The extraction technique that achieved the highest extraction yield (35%) was the one that used hexane as a solvent. The extraction using 32% ethanol obtained by mechanical pressing and extraction reached 25% yield. For the enzymatic extraction, the experimental design indicated that the extraction yield was most affected by the effect of the combination of temperature and time. The maximum yield obtained in this extraction was 16%. After the step of obtaining the oil was accomplished the synthesis of biodiesel by the conventional method and the in situ technique. The method of conventional transesterification was obtained a content of 100% and esters by in situ technique was also obtained in 100% in the experimental point 7, with a molar ratio oil / alcohol 1:420, Temperature 60°C in 5% weight KOH with the reaction time of 1.5 h. By the experimental design, it was found that the variable that most influenced the ester content was late the percentage of catalyst. By physico-chemical analysis it was observed that the biodiesel produced by the in situ method fell within the rules of the ANP, therefore this technique feasible, because does not require the preliminary stage of oil extraction and achieves high levels of esters

Expressão imuno-histoquímica da e-caderina e da ß-catenina em carcinoma epidermóide oral com e sem metástase nodal

The adhesion molecules E-cadherin and β-catenin have been studied as possible markers to distinguish carcinomas with and without metastatic potential. The objective of this research was to study the imunohistochemistry expression of the E-cadherin and β-catenin in oral squamous cell carcinoma (OSCC), aiming to contribute for the better understanding of the biological behavior of this lesion. The sample consisted of 30 cases of OSCC, being 15 of tongue and 15 of lower lip. The profile and intensity of labeling and semi quantitative analysis of the percentage of immunopositive tumoral cells in membrane for E-cadherin and β-catenin had been related with the anatomical localization of the lesion, the presence or not of nodal metastasis and the histological grade of malignancy in the invasive front area of the tumor. It was registered the presence or not of cytoplasmic and nuclear labeling of the β-catenin. The results had been submitted to the statistical analysis, being used the Mann-Whitney Test, the Fisher Test and the Spearman Correlation Coefficient (α=0, 05). The results showed that the expression in membrane for E-cadherin and β-catenin was, predominantly, the heterogeneous profile in the lower lip and tongue carcinomas, as well as in the cases with and without nodal metastasis. It was not observed significant statistical difference between expression profile and amount of immunopositive cells for E-cadherin, β-catenin and the anatomical localization of the lesion and for the presence or not of nodal metastasis. However, there was significant difference of the reduced expression of these proteins with the high score of malignancy. It was verified that the expression of the β-catenin in cytoplasm was present in 22 (73.33%) of the 30 analyzed cases, and 6 cases (20%) showed nuclear expression. The statistical analysis detected significant association between the expression of the β-catenin in the cytoplasm with the histological grade of malignancy, being this molecule more frequently present in the cytoplasm in the cases of high score of malignancy. It was concluded that the reduced immunoexpression of these proteins in membrane can be related with the lowest cellular differentiation, as well as with the pattern of invasion in nests and isolated cells, demonstrated in the cases of OSCC with high histological grade of malignancy

Avaliação das propriedades físico-químicas de sistemas a base de carboximetilcelulose e poli (N-isopropilacrilamida) em soluções aquosas para aplicação na indústria do petróleo

Sustainable development is a major challenge in the oil industry and has aroused growing interest in research to obtain materials from renewable sources. Carboxymethylcellulose (CMC) is a polysaccharide derived from cellulose and becomes attractive because it is water-soluble, renewable, biodegradable and inexpensive, as well as may be chemically modified to gain new properties. Among the derivatives of carboxymethylcellulose, systems have been developed to induce stimuli-responsive properties and extend the applicability of multiple-responsive materials. Although these new materials have been the subject of study, understanding of their physicochemical properties, such as viscosity, solubility and particle size as a function of pH and temperature, is still very limited. This study describes systems of physical blends and copolymers based on carboxymethylcellulose and poly (N-isopropylacrylamide) (PNIPAM), with different feed percentage compositions of the reaction (25CMC, 50CMC e 75CMC), in aqueous solution. The chemical structure of the polymers was investigated by infrared and CHN elementary analysis. The physical blends were analyzed by rheology and the copolymers by UV-visible spectroscopy, small-angle X-ray scattering (SAXS), dynamic light scattering (DLS) and zeta potential. CMC and copolymer were assessed as scale inhibitors of calcium carbonate (CaCO3) using dynamic tube blocking tests and chemical compatibility tests, as well as scanning electron microscopy (SEM). Thermothickening behavior was observed for the 50 % CMC_50 % PNIPAM and 25 % CMC_75 % PNIPAM physical blends in aqueous solution at concentrations of 6 and 2 g/L, respectively, depending on polymer concentration and composition. For the copolymers, the increase in temperature and amount of PNIPAM favored polymer-polymer interactions through hydrophobic groups, resulting in increased turbidity of polymer solutions. Particle size decreased with the rise in copolymer PNIPAM content as a function of pH (3-12), at 25 °C. Larger amounts of CMC result in a stronger effect of pH on particle size, indicating pH-responsive behavior. Thus, 25CMC was not affected by the change in pH, exhibiting similar behavior to PNIPAM. In addition, the presence of acidic or basic additives influenced particle size, which was smaller in the presence of the additives than in distilled water. The results of zeta potential also showed greater variation for polymers in distilled water than in the presence of acids and bases. The lower critical solution temperature (LCST) of PNIPAM determined by DLS corroborated the value obtained by UV-visible spectroscopy. SAXS data for PNIPAM and 50CMC indicated phase transition when the temperature increased from 32 to 34 °C. A reduction in or absence of electrostatic properties was observed as a function of increased PNIPAM in copolymer composition. Assessment of samples as scale inhibitors showed that CMC performed better than the copolymers. This was attributed to the higher charge density present in CMC. The SEM micrographs confirmed morphological changes in the CaCO3 crystals, demonstrating the scale inhibiting potential of these polymers

Mecanismos de transmissão de preços e parcelas de mercado: uma análise sobre as exportações brasileiras de manga

Climate and environmental conditions allowed Brazil to become one of the largest producers of tropical fruits in the world. The São Francisco Valley, over the years, has emerged as the main fruit-producing region of the country, especially mangos and grapes. The mango, which is produced in this region, has reached a good international position, especially in European and American markets. However, the domestic price has absorbed more and more the impact of fluctuations in the international market expectations affecting the production and marketing of producers. The objective of the study is to analyze the transmission ratio of export prices of the mango, with the American market prices and the European Union in the period from 2003 to 2013. It is intended also to analyze the factors affecting the fluctuations of exports Brazilian mango for the main import markets. To achieve the proposed objectives, we used, in the methodology, the autoregressive vector model, in order to find the price transmission mechanism and the mechanisms of impacts through the impulse response function. We also used, the Constant Market Share model, in order to observe the importance of the effects competitiveness, destination, and growth in world trade on the changes of Brazilian mango exports in the period. The data used were obtained from the database of the Ministry of Development and Foreign Trade - MIDIC and FAOSTAT (Food and Agriculture Organization of the United Nations). Among the results, it was found that the Brazilian domestic prices are influenced by the US market price, and that price shocks promoted this market can impact on the growth of the internal prices for several months. It was noted also that the competitiveness effect accounted for the largest portion of the effective growth of Brazilian exports, in other word, the country has improved its competitiveness among the other exporting countries.

Qualidade dos serviços hoteleiros: percepções dos turistas de negócios de Teresina-PI

Business tourism is one of tourist segments with different market characteristics in relation to others segmentations, such as low seasonality, there is no requirement of natural attractions, it serves as destination projection and it generates profitable larger numbers. Due to the context around business travels, the hotel so many times has a fundamental whole among the elements of the production chain in this segmentation. Business tourism in Teresina is the primary segmentation of the capital, since it represents almost 70% of hotel demand; hence this research has as objective to evaluate through the perceptions of business travelers, the level of quality services of hotels of Teresina. The research is exploratory and descriptive, of functionalist character. This study is characterized by qualitative and quantitative research, supported by a basis of methodological pluralism. For primary data collection was performed applying a suitable research instrument of SERVPERF model (Service Performance). The universe of this study were Teresina's accommodations, restricted to only those that fit in hotel category and it was inside metropolitan area of Teresina. The study subjects were business travelers who were hosted in these hotels. For the analysis, it was considered certain factors: descriptive analysis, factor analysis, correlation matrix analysis of the variables; It was still compiling a graphic of lexicons obtained in the survey about respondent's the notion of quality of vision in the hotel service; Finally, qualitative analysis was based on the theories of marketing, targeting and quality of tourism services applied. The results show that the Teresina hotel service is on a regular average, especially for Reliability and Safety dimensions were highlighted. Whereas, the factor analysis showed the emergence of two factors to explain "Empathy" dimension, one of this is about the organization and the other one is about consumer. And by Lexicometria was possible to observe the importance to the customer of other variables such as: personal aspects, price and location for this tour segmentation.

Estudo de simulação de reservatórios para o desenvolvimento de um campo do nordeste brasileiro

In the last 16 years emerged in Brazil a segment of independent producers with focus on onshore basins and shallow waters. Among the challenges of these companies is the development of fields with projects with a low net present value (NPV). The objective of this work was to study the technical-economical best option to develop an oil field in the Brazilian Northeast using reservoir simulation. Real geology, reservoir and production data was used to build the geological and simulation model. Due to not having PVT analysis, distillation method test data known as the true boiling points (TBP) were used to create a fluids model generating the PVT data. After execution of the history match, four development scenarios were simulated: the extrapolation of production without new investments, the conversion of a producing well for immiscible gas injection, the drilling of a vertical well and the drilling of a horizontal well. As a result, from the financial point of view, the gas injection is the alternative with lower added value, but it may be viable if there are environmental or regulatory restrictions to flaring or venting the produced gas into the atmosphere from this field or neighboring accumulations. The recovery factor achieved with the drilling of vertical and horizontal wells is similar, but the horizontal well is a project of production acceleration; therefore, the present incremental cumulative production with a minimum rate of company's attractiveness is higher. Depending on the crude oil Brent price and the drilling cost, this option can be technically and financially viable.

O centro de Fortaleza como lugar de moradia

The present study has the objective of analyzing how the ways of dwelling influences the uses and the functional and symbolic appropriations of the urban space in Fortaleza city center, through the perspective of the residents and their relation with the living place. Scenarios of development and degradation of its urban space have marked the city center of Fortaleza. The intensification of the commercial and services occupation promoted through the years, paradoxically, the valorization of the land price and the devalorization of the residential use. Thus, the residential occupation was consolidated in a discontinuous way, being concentrated mainly in the external limits of the historical core of the neighborhood. The research is structured over the delimitation of an area and the selection of multifamily residential buildings, built since the 1960s, close to the central core of the neighborhood. The spatial configuration analysis of the selected residential buildings, and their relations with the urban surroundings and the land uses, reveals different aspects related to the urban vitality, producing impacts over the ways of dwelling constituted by the daily life of the residents. The study of the ways of dwelling involves the comprehension that the dwelling is beyond the private residential boundaries and the functional occupation. The conceptual base of this research is developed over the perspective that the dwelling represents a fundamental aspect of the human condition, allowing the person to relate with the space in an essential way (HEIDEGGER, 2012). In this perspective of the dwelling, the space reunites the mental and the cultural, the social and the historical, being marked by simultaneous logics of the conceived, the perceived and the lived space (LEFEVBRE, 2006). The development of this study, over the point of view of the neighborhood residents, is inserted in the perspective of the lived space, related to the concept of place, understood as a qualitative phenomenon, giving essence and identity to the space. The place of dwelling, marked by coexistences, is one of the structural elements of the urban land use, and potential for the rehabilitation of the central areas in big cities. Therefore, the study starts from the hypothesis that the location, the nearby land uses and the spatial configuration of the residential buildings affect the ways of dwelling, in other words the residents dissolve the boundaries of the shelter and experience the urban space, from the dwelling place. The requalification of the dwelling is opposed to the residential space based in functionality, in hierarchy, in self sufficiency, in standardization and in the reproduction of the urban space, materialized in the dense contemporary residential buildings, that are unrelated to the city. The stages of the research involved the spatial configuration analysis of the selected residential buildings and their surrounding, the land use mapping and interviews with the residents. The collected data allowed verifying that the buildings are located in areas presenting heterogeneous land uses, with a great number of residents and users. However, these aspects are not sufficient to promote the vitality of the public spaces in the neighborhood, since the people movement in the streets is controlled by the opening hours of the predominant commercial use in the area. The word of the residents, collected in interviews, indicate that the conservation conditions of the public spaces and the insecurity influences their everyday relations with the place of dwelling, affecting fundamental aspects for the dwelling requalification in the central area of Fortaleza.

O centro de Fortaleza como lugar de moradia

The present study has the objective of analyzing how the ways of dwelling influences the uses and the functional and symbolic appropriations of the urban space in Fortaleza city center, through the perspective of the residents and their relation with the living place. Scenarios of development and degradation of its urban space have marked the city center of Fortaleza. The intensification of the commercial and services occupation promoted through the years, paradoxically, the valorization of the land price and the devalorization of the residential use. Thus, the residential occupation was consolidated in a discontinuous way, being concentrated mainly in the external limits of the historical core of the neighborhood. The research is structured over the delimitation of an area and the selection of multifamily residential buildings, built since the 1960s, close to the central core of the neighborhood. The spatial configuration analysis of the selected residential buildings, and their relations with the urban surroundings and the land uses, reveals different aspects related to the urban vitality, producing impacts over the ways of dwelling constituted by the daily life of the residents. The study of the ways of dwelling involves the comprehension that the dwelling is beyond the private residential boundaries and the functional occupation. The conceptual base of this research is developed over the perspective that the dwelling represents a fundamental aspect of the human condition, allowing the person to relate with the space in an essential way (HEIDEGGER, 2012). In this perspective of the dwelling, the space reunites the mental and the cultural, the social and the historical, being marked by simultaneous logics of the conceived, the perceived and the lived space (LEFEVBRE, 2006). The development of this study, over the point of view of the neighborhood residents, is inserted in the perspective of the lived space, related to the concept of place, understood as a qualitative phenomenon, giving essence and identity to the space. The place of dwelling, marked by coexistences, is one of the structural elements of the urban land use, and potential for the rehabilitation of the central areas in big cities. Therefore, the study starts from the hypothesis that the location, the nearby land uses and the spatial configuration of the residential buildings affect the ways of dwelling, in other words the residents dissolve the boundaries of the shelter and experience the urban space, from the dwelling place. The requalification of the dwelling is opposed to the residential space based in functionality, in hierarchy, in self sufficiency, in standardization and in the reproduction of the urban space, materialized in the dense contemporary residential buildings, that are unrelated to the city. The stages of the research involved the spatial configuration analysis of the selected residential buildings and their surrounding, the land use mapping and interviews with the residents. The collected data allowed verifying that the buildings are located in areas presenting heterogeneous land uses, with a great number of residents and users. However, these aspects are not sufficient to promote the vitality of the public spaces in the neighborhood, since the people movement in the streets is controlled by the opening hours of the predominant commercial use in the area. The word of the residents, collected in interviews, indicate that the conservation conditions of the public spaces and the insecurity influences their everyday relations with the place of dwelling, affecting fundamental aspects for the dwelling requalification in the central area of Fortaleza.

Síntese do Poli (ácido láctico) por policondensação direta utilizando um planejamento fatorial

The environmental impact caused by the disposal of non-biodegradable polymer packaging on the environment, as well as the high price and scarcity of oil, caused increase of searches in the area of biodegradable polymers from renewable resources were developed. The poly (lactic acid) (PLA) is a promising polymer in the market, with a large availability of raw material for the production of its monomer, as well as good processability. The aimed of this study was synthesis PLA by direct polycondesation of lactic acid, using the tool of experimental design (DOE) (central composite rotatable design (CCRD)) to optimize the conditions of synthesis. The polymer obtained was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), viscosimetric analysis, differential scanning calorimeter (DSC) and size exclusion chromatography (SEC). The results confirmed the formation of a poly (lactic acid) semicrystalline in the syntheses performed. Through the central composite rotatable design was possible to optimize the crystallization temperature (Tc) and crystallinity degree (Xc). The crystallization temperature maximum was found for percentage of catalyst around the central point (0,3 (%W)) and values of time ranging from the central point (6h) to the upper level (+1) (8h). The crystallization temperature maximum was found for the total synthesis time of 4h (-1) and percentage of catalyst 0,1(W%) (-1). The results of size exclusion chromatography (SEC) showed higher molecular weights to 0,3 (W%) percent of catalyst and total time synthesis of 3,2h