15 resultados para d(x2)-(y2) and d(xy) order parameters
em Universidade Federal do Rio Grande do Norte(UFRN)
Resumo:
Brazil, one of the largest agricultural producers in the world, has managed in recent years to significantly improve its production. However, in response to this advance in the agro-industrial sector, the generation of agro-industrial residues has also increased. New technological alternatives have to be implemented in order to bring economic and rational use of this material and drying is one of the possible choices. Considering the great importance that bioactive compounds present for food science and technology, this research aims to evaluate the air-drying process of acerola residue in a tray convective drier under controlled temperature (60, 70 e 80ºC), air velocity (4.0, 5.0 e 6.0 m/s) and material width (0.5, 0.62 e 0.75 cm) by applying an experimental planning 23 + 3. Based on that, the impact on physical-chemical characteristics, color, bioactive compounds concentration and antioxidant activity of dried acerola waste was evaluated, having the in natura and freeze dried waste as control groups. Dried acerola residue presented natural pigments, mainly carotenoids (143.68 - 68.29 mg/g) and anthocyanins (290.92 - 90.11 mg/100 g), which explain the red and yellow instrumental color parameters observed. The acerola residue powder is also rich in phenolic compounds (3261.11 -2692.60 mgGAEeq/100g), proanthocyanidins (61.33-58.46 eq/100g), ascorbic acid (389.44 739.29 mg/100 g) and DPPH antioxidant activity (20.91 24.72 μg Trolox eq/g). Results show decreased concentration of phenolic compounds, anthocyanins, carotenoids, proanthocyanidins and ascorbic acid caused by the air-drying process. However, even after the observed drying losses, the acerola residue powder can be considered a high value food ingredient, considering the high bioactive compounds concentration found in the final product, as well as the colorimetric characterization and microbiological stability of the dried powder
Resumo:
This work presents a theoretical and numerical analysis of parameters of a rectangular microstrip antenna with bianisotropic substrate, and including simultaneously the superconducting patch. The full-wave Transverse Transmission Line - TTL method, is used to characterize these antennas. The bianisotropic substrate is characterized by the permittivity and permeability tensors, and the TTL gives the general equations of the electromagnetic fields of the antennas. The BCS theory and the two fluids model are applied to superconductors in these antennas with bianisotropic for first time. The inclusion of superconducting patch is made using the complex resistive boundary condition. The resonance complex frequency is then obtained. Are simulated some parameters of antennas in order to reduce the physical size, and increase the its bandwidth. The numerical results are presented through of graphs. The theoretical and computational analysis these works are precise and concise. Conclusions and suggestions for future works are presented
Resumo:
In this dissertation new models of propagation path loss predictions are proposed by from techniques of optimization recent and measures of power levels for the urban and suburban areas of Natal, city of Brazilian northeast. These new proposed models are: (i) a statistical model that was implemented based in the addition of second-order statistics for the power and the altimetry of the relief in model of linear losses; (ii) a artificial neural networks model used the training of the algorithm backpropagation, in order to get the equation of propagation losses; (iii) a model based on the technique of the random walker, that considers the random of the absorption and the chaos of the environment and than its unknown parameters for the equation of propagation losses are determined through of a neural network. The digitalization of the relief for the urban and suburban areas of Natal were carried through of the development of specific computational programs and had been used available maps in the Statistics and Geography Brazilian Institute. The validations of the proposed propagation models had been carried through comparisons with measures and propagation classic models, and numerical good agreements were observed. These new considered models could be applied to any urban and suburban scenes with characteristic similar architectural to the city of Natal
Resumo:
Why students of 6th year still present oral marks in written? To answer this question our paper presents what they are and how writing and grammatical deviations occur and emerged in an attempt to expand on these studies. The same objective to evaluate the presence of these deviations in genres produced by students of the 6th year of the Municipal School Manoel Catarino Filho and check if there are more variation deviations or grammatical deviations. It also aims to improve the linguistic and discursive ability of students in various traffic environments of certain genres and consequently the formation of active readers and writers. In order to better understand how this process occurs, the text starts of the socio discursive conception of gender, with the theoretical background studies of Bakhtin (1992) and Marcuschi (2002) about this conception and the rhetoric conception of Aristoteles and Platão. The text underlies even the works of Callou (2007), Neves (2003), Faraco (2002), Franchi (2006) and Cagliari (2005) on the Grammar School, linguistic variation as also on the sociolinguistic parameters as well in research on the phonetics and phonology of Oliveira e Nascimento (1990), Seara (2009), Hora (2009) and in the PCN. To compose the corpus of this study we collected 23 texts produced by students to serve as a data source for analysis of the presented deviations by quantitative and qualitative research method, in which categorize the deviations found in two groups: oral and linguistic variation deviations and writing and grammar deviations. The results showed that there was a rate of occurrence of oral and variation deviations greater of writing and grammar deviations. We concluded that the orality has a great influence on the written production of students. Finally, we propose some activities aimed at minimizing the occurrence of deviations in written productions of the students.
Resumo:
This present study analyses the relationship between national culture and entrepreneurship, in order to contribute in understanding the impact and the influence of Brazilian culture under the business practices of foreign entrepreneur on the tourism area of Rio Grande do Norte state. Researchers in entrepreneurship field, such as Schumpeter (2005), Weber (2006), McClelland (1972), Murphy, Liao, Welsch (2006), Peyrefitte (1999), Blanchflower (1988), Filion (2000), among others, and in the national culture, high-lighting Caldas and Woods (1999), Hofstede (1997) and Barros and Prates (1996), are put together to create a starting point to this present research, that reaches out for a differential approach, in order to create a correlation between Brazilian culture and the foreign entrepreneur, who chose Rio Grande do Norte state to live and invest. It was observed that in the case of the Switzerland entrepreneur, where the cultural difference is more strong, either in Hofstede's perspective than in Brazilian s authors, the management practices are more negatively affected. The rationalization adopted by the entrepreneur and the employee s logic are in battle in a day-to-day operation of the company. In the case of the Argentinean entrepreneur, the cultural difference exists, but it does not impact as much, because of her personal characteristics and the similarities of Latin culture than surfaces the differences. Finally, this study showed the necessity of analyzing the enterprising regarding the cultural issue, in a way to highlight the different rationalities in different atmospheres where it is practiced the enterprise
Resumo:
Homosexuality has been gaining strength in Cinema from the late twentieth century, when there is a dissemination of freedoms around the peripheral or marginal sexualities. Based on this assumption, it was formulated in the dissertation work, an analysis of the relationship between Cinema and Sexuality in order to understand, describe, reflect and analyze possible changes around the performative behaviors of male homosexual from the introduction of them in film production, arising from the mass culture industry. These productions are located in three different decades. In this case, the Cinema has not only the reproductive character of realities, but also a producing agent and consolidating them. The methodology applied was discourse analysis of three film works, namely La Cage aux Folles (1978), In & Out (1997) and Boat Trip (2002). The image, research object of this work, is developed by a mass culture that will produce mass identities which is characterized by crystallization of clichés around the gay world
Resumo:
This paper presents a research realized with Physics, Chemistry and Biology teachers, and it aimed to evaluate: 1) the development level of those teachers regarding the abilities that make possible to teach high school students about how to measure in practical and experimental work; 2) the formatives necessities regarding those abilities; and 3) the order of priority for teacher´s formation regarding those abilities. The study is based on the activity theory, from A. N. Leontiev (1983), since we considerer the teacher´s formation a kind of activity for which the category necessity is source of motivation and in which is a necessary condition for professionality and for the professional development. A questionnaire with open and closed questions was applied to 116 teachers during three pedagogic workshops realized to dynamize the science laboratory. The instrument allowed us to obtain the personal and professional profile of the participants, as well as their development level, their formative necessities and their order of priority about the teaching of the abilities related to the work of testing measuring hypothesis, regarding: a) to operationalize variables of a hypothesis in experimental work; b) to measure in practical and experimental work; c) to estimate possible measuring mistakes and use proper procedures to minimize them; d) to estimate the validity of a measuring; and e) to estimate the confiability of a measuring. The research results indicated some limitations of the teachers about their development level in all the analyzed abilities. More than 90% of the teachers considered those deficiencies as necessities of the continuing formation. Most of them (about 54%) expressed immediate priority for formation in each one of the abilities. From a correlation, using the statistic chi-square test, between the development level and the formative necessities for the five abilities, the obtained results allow us to assure that, for all those teaching abilities, there is a strong correlation between the development level and the formative necessity. This situation is symptomatic of the importance of approaching more the science teaching and the teacher´s formation on practical and experimental work in high school as key-component of scientific education in basic education. The obtained results can contribute, as subsidy, for continuing formation courses, having as base the necessities that constitute motivation elements of the teachers for professional development
Resumo:
Recently, an amazing development has been observed in telecommunication systems. Two good examples of this development are observed in mobile communication and aerospace systems. This impressive development is related to the increasing need for receiving and transmitting communication signals. Particularly, this development has required the study of new antennas and filters. This work presents a fullwave analysis of reflectarrays. The considered structures are composed by arrays of rectangular conducting patches printed on multilayer dieletric substrates, that are mounted on a ground plane. The analysis is developed in the spectral domain, using an equivalent transmission line method in combination with Galerkin method. Results for the reflection coefficient of these structures are presented and compared to those available in the literature. A good agreement was observed. Particularly, the developed analysis uses the transmission lines theory in combination with the incident potentials and the field continuity equations, at the structures interfaces, for obtaining the scattered field components expressions as function of the patch surface currents and of the incident field. Galerkin method is used to determine the unknown coefficients in the boundary value problem. Curves for the reflection coefficient of several reflectarray geometries are presented as function of frequency and of the structural parameters
Resumo:
Image compress consists in represent by small amount of data, without loss a visual quality. Data compression is important when large images are used, for example satellite image. Full color digital images typically use 24 bits to specify the color of each pixel of the Images with 8 bits for each of the primary components, red, green and blue (RGB). Compress an image with three or more bands (multispectral) is fundamental to reduce the transmission time, process time and record time. Because many applications need images, that compression image data is important: medical image, satellite image, sensor etc. In this work a new compression color images method is proposed. This method is based in measure of information of each band. This technique is called by Self-Adaptive Compression (S.A.C.) and each band of image is compressed with a different threshold, for preserve information with better result. SAC do a large compression in large redundancy bands, that is, lower information and soft compression to bands with bigger amount of information. Two image transforms are used in this technique: Discrete Cosine Transform (DCT) and Principal Component Analysis (PCA). Primary step is convert data to new bands without relationship, with PCA. Later Apply DCT in each band. Data Loss is doing when a threshold discarding any coefficients. This threshold is calculated with two elements: PCA result and a parameter user. Parameters user define a compression tax. The system produce three different thresholds, one to each band of image, that is proportional of amount information. For image reconstruction is realized DCT and PCA inverse. SAC was compared with JPEG (Joint Photographic Experts Group) standard and YIQ compression and better results are obtain, in MSE (Mean Square Root). Tests shown that SAC has better quality in hard compressions. With two advantages: (a) like is adaptive is sensible to image type, that is, presents good results to divers images kinds (synthetic, landscapes, people etc., and, (b) it need only one parameters user, that is, just letter human intervention is required
Análise espectral de reflectarrays com substrato de duas camadas dielétricas anisotrópicas uniaxiais
Resumo:
Recently, an amazing development has been observed in telecommunication systems. Two good examples of this development are observed in mobile communication and aerospace systems. This impressive development is related to the increasing need for receiving and transmitting communication signals. Particularly, this development has required the study of new antennas and filters. This work presents a fullwave analysis of reflectarrays. The considered structures are composed by arrays of rectangular conducting patches printed on multilayer dieletric substrates, that are mounted on a ground plane. The analysis is developed in the spectral domain, using an equivalent transmission line method in combination with Galerkin method. Results for the reflection coefficient of these structures are presented and compared to those available in the literature. A good agreement was observed. Particularly, the developed analysis uses the transmission lines theory in combination with the incident potentials and the field continuity equations, at the structures interfaces, for obtaining the scattered field components expressions as function of the patch surface currents and of the incident field. Galerkin method is used to determine the unknown coefficients in the boundary value problem. Curves for the reflection coefficient of several reflectarray geometries are presented as function of frequency and of the structural parameters
Resumo:
This research study deals with the production and distribution of drinking water with quality and safety in order to meet the needs of the Man. Points out the limitations of the methodology for assessing water quality in use today. Approaches the recommendations of the World Health Organization (WHO) for adoption, by the companies responsible for producing and distributing water, of assessment methodologies and risk management (HACCP), in order to ensure the quality and safety of water drinking. Suggests strategies for implementing the plan for water safety plan. Uses the process of water production, composed by Maxaranguape river basin, the water treatment plant and distribution system, which is part of the Plan for Expansion of the Supply System of Natal, as case study. The results, it was possible to devise strategies for implementation of the Water Safety Plan (WSP), which comprises the following steps: a) a preliminary stage. b) assessment system. c) process monitoring. d) management plan and e) validation and verification of the PSA. At each stage are included actions for its implementation. The implementation of the PSA shows a new type of water production, in which the fountain as a whole (watershed and point of capture), the Water Treatment Plant (WTP) and distribution, shall compose the production process, over which to build quality and safety of the final product (drinking water)
Resumo:
This study aims to understand as the children who show expressive behaviors of antisocial trends at Núcleo de Ação Social da Praia do Meio in Natal-RN city, linked to Secretaria Municipal do Trabalho e Assistência Social-SEMIT, which experience the relation with the social educator in role of caregiver. This matter was investigated within an interpretation and approach qualitative view of the social phenomena, using the Thematic Analysis technique of drawings and stories which express the relation with the caregiver gotten in sessions of playful interactions between child and researcher in order to understand the child experiences with the social educator. The used theoretical referential is by D. W. Winnicott who associates the social trend to a failure of environment in child holding. The subjects expressed the need of a firm and protective environment and they look for this in NASPM educators. Moreover, they show as solitude and vulnerability take part their lives due to the lack of emotional holding on family that favors the involvement with violent groups. But, it is worth pointing out that the children value the Nucleus environment when has offered them a safe holding which can be positive the established linking with it. Such conclusion points out to the possibility, recognized theoretically, that exists from these children to resume the way of healthy development
Resumo:
This thesis focuses on the coprecipitation synthesis method for preparation of ceramic materials with perovskite structure, their characterization and application as catalytic material in the reaction of converting CO to CO2 developing a methodological alternative route of synthesis from the middle via oxalate coprecipitation material SrCo0,8Fe0,2O3-d. In order to check the influence of this method, it was also synthesized using a combined citrate - EDTA complexing method. The material was characterized by: X-ray diffraction (XRD), Rietveld refinement method, thermogravimetry and differential thermo analysis (TG / DTA), scanning (SEM) and transmission (TEM) electron microscopy, particle size distribution and surface analysis method BET. Both methods led to post-phase synthesis, with pH as a relevant parameter. The synthesis based on the method via oxalate coprecipitation among particles led to the crystalline phase as those obtained using a combined citrate - EDTA complexing method under the same conditions of heat treatment. The nature of the reagent used via oxalate coprecipitation method produced a material with approximately 80 % lower than the average size of crystallites. Moreover, the via oxalate coprecipitation method precursors obtained in the solid state at low temperature (~ 26 oC), shorter synthesis, greater thermal stability and a higher yield of around 90-95 %, maintaining the same order of magnitude the crystallite size that the combined citrate - EDTA complexing method. For purposes of comparing the catalytic properties of the material was also synthesized by the using a combined citrate - EDTA complexing method. The evaluation of catalytic materials SrCo0,8Fe0,2O3-d LaNi0,3Co0,7O3-d was accompanied on the oxidation of CO to CO2 using a stainless steel tubular reactor in the temperature range of 75-300 oC. The conversion CO gas was evaluated in both materials on the results shaved that the firm conversion was loves for the material LaNi0,3Co0,7O3-d
Resumo:
The performance of algorithms for fault location i n transmission lines is directly related to the accuracy of its input data. Thus, fa ctors such as errors in the line parameters, failures in synchronization of oscillographic recor ds and errors in measurements of voltage and current can significantly influence the accurac y of algorithms that use bad data to indicate the fault location. This work presents a new method ology for fault location in transmission lines based on the theory of state estimation in or der to determine the location of faults more accurately by considering realistic systematic erro rs that may be present in measurements of voltage and current. The methodology was implemente d in two stages: pre-fault and post- fault. In the first step, assuming non-synchronized data, the synchronization angle and positive sequence line parameters are estimated, an d in the second, the fault distance is estimated. Besides calculating the most likely faul t distance obtained from measurement errors, the variance associated with the distance f ound is also determined, using the errors theory. This is one of the main contributions of th is work, since, with the proposed algorithm, it is possible to determine a most likely zone of f ault incidence, with approximately 95,45% of confidence. Tests for evaluation and validation of the proposed algorithm were realized from actual records of faults and from simulations of fictitious transmission systems using ATP software. The obtained results are relevant to show that the proposed estimation approach works even adopting realistic variances, c ompatible with real equipments errors.
Resumo:
This present study analyses the relationship between national culture and entrepreneurship, in order to contribute in understanding the impact and the influence of Brazilian culture under the business practices of foreign entrepreneur on the tourism area of Rio Grande do Norte state. Researchers in entrepreneurship field, such as Schumpeter (2005), Weber (2006), McClelland (1972), Murphy, Liao, Welsch (2006), Peyrefitte (1999), Blanchflower (1988), Filion (2000), among others, and in the national culture, high-lighting Caldas and Woods (1999), Hofstede (1997) and Barros and Prates (1996), are put together to create a starting point to this present research, that reaches out for a differential approach, in order to create a correlation between Brazilian culture and the foreign entrepreneur, who chose Rio Grande do Norte state to live and invest. It was observed that in the case of the Switzerland entrepreneur, where the cultural difference is more strong, either in Hofstede's perspective than in Brazilian s authors, the management practices are more negatively affected. The rationalization adopted by the entrepreneur and the employee s logic are in battle in a day-to-day operation of the company. In the case of the Argentinean entrepreneur, the cultural difference exists, but it does not impact as much, because of her personal characteristics and the similarities of Latin culture than surfaces the differences. Finally, this study showed the necessity of analyzing the enterprising regarding the cultural issue, in a way to highlight the different rationalities in different atmospheres where it is practiced the enterprise