Polaritons em materiais magnéticos nanoestruturados

In this work we present a theoretical study about the properties of magnetic polaritons in superlattices arranged in a periodic and quasiperiodic fashíons. In the periodic superlattice, in order to describe the behavior of the bulk and surface modes an effective medium approach, was used that simplify enormously the algebra involved. The quasi-periodic superlattice was described by a suitable theoretical model based on a transfer-matrix treatment, to derive the polariton's dispersion relation, using Maxwell's equations (including effect of retardation). Here, we find a fractal spectra characterized by a power law for the distribution of the energy bandwidths. The localization and scaling behavior of the quasiperiodic structure were studied for a geometry where the wave vector and the external applied magnetic field are in the same plane (Voigt geometry). Numerical results are presented for the ferromagnet Fe and for the metamagnets FeBr2 and FeCl2

Valores de referência para pressão inspiratória nasal SNIFF na população brasileira

The strength of respiratory muscle are frequently assessed by maximal inspiratory and expiratory pressure, however, the maneuvers to assess PImax and PEmax are difficult for many patients. The sniff nasal inspiratory pressure (SNIP) is a simple and noninvasive technique use to assess inspiratory muscles strength. Reference values have been previous established for SNIP in adults but no previous studies have provided reference values for SNIP in adult Brazilian population. The main objective of this study were propose reference values of SNIP for Brazilian population through establishment of relationship between anthropometric measurements, physical activity profile and SNIP and at the same time compare the values obtained with reference values previously published. We studied 117 subjects (59 male and 58 female) distributed in different age grouped 20-80 years old. The results showed on significant positive relationship between SNIP and height and negative correlation with age (p<0.05). In the multiple linear regression analysis only age continued to have an independent predictive role for the two dependent variables that correlated with SNIP. The values of SNIP found in Brazilian population were higher when compared with predict values of previous studies. The results of this study provide reference equations of SNIP for health Brazilian population from 20 to 80 years old

Equacões preditivas para as pressões respiratórias estáticas máximas de adolescentes brasileiros

Introduction: The reference values and prediction equations for maximal respiratory pressures (MRP) differ significantly between the available studies. This large discrepancy can be attributed to the different methodologies proposed. Although the importance of MRP is widely recognized, there are no Brazilian studies that provide predictive equations and reference values for PRM adolescents. Objectives: The purpose of this study was to provide normal values and propose predictive equations for maximal static respiratory pressures of Brazilian adolescents. Methods: An observational cross-sectional study, which evaluated 182 adolescents of both sexes aged between 12 and 18 years, enrolled in schools of the state and private in the city of Natal / RN. The selection of schools and participants of the study was randomly through a lottery system. The spirometric evaluation was performed through the digital spirometer One Flow FVC prior to the assessment of respiratory muscle strength. The MICs were measured with MVD digital manometer 300. Statistical analysis was performed using the SPSS 17.0 software STATISTICS, assigning the significance level of 5%. The normality of data distribution was verified using the Kolmogorov-Smirnov (KS). The descriptive analysis was expressed as mean and standard deviation. We used one-way ANOVA test to verify the difference of the averages of MRPs between age and gender and comparing the averages of MRPs between levels of physical activity. The test t'Student unpaired compared the averages of MRPs being ages and sexes. The comparison of mean values obtained in this study PRM with the values predicted using the equations mentioned above was relizada by testing paired t'Student. To verify the correlation between the PRM and the independent variables (age, weight, height) was used Pearson correlation test. Levene's test evaluated the homogeneity of variance. To obtain predictive equations analysis was used stepwise multiple linear regression. Results: There was no significant difference in mean age between the PRM. The male adolescents, regardless of age, showed superiority in MRP values when compared to the opposite sex. Weight, height and sex correlated with the PRM. Regression analysis suggested in this study, pointed out that the weight and sex had an influence in MIP and MEP only in relation to sex influenced. The mean for each PRM adolescents classified as very active were superior to those observed in adolescents classified as irregularly active. Conclusion: This study provides reference values and two models of predictive equations for maximal inspiratory and expiratory pressures, and to establish the lower limits of normality that will serve as an indispensable condition for careful evaluation of respiratory muscle strength in Brazilian adolescents

Associação entre diferentes marcadores antropométricos com variáveis espirométricas e de força muscular respiratória em obesos mórbidos

A obesidade é uma epidemia global em alarmante ascensão. Caracterizada pelo excesso de gordura corporal subcutânea, de caráter multifatorial, está relacionada ao surgimento de diversas co-morbidades, entre elas, várias alterações respiratórias, estas se tornam mais intensas quanto maior o grau de obesidade. Não há consenso na relação entre os marcadores de adiposidade geral ou específicos e suas repercussões sobre a função ventilatória, especialmente em relação à sobrecarga muscular respiratória. Objetivo: Analisar a relação entre marcadores antropométricos e variáveis espirométricas e de força muscular respiratória em indivíduos com obesidade mórbida. Métodos: Estudo transversal entre setembro de 2007 e outubro de 2012. Participaram da pesquisa 163 obesos mórbidos (37.1±9.8 anos e IMC=49.0±5.88 Kg/m2) sem alterações espirométricas. Foram observadas as associações entre Índice de Massa Corporal-IMC, adiposidade localizada (Circunferências de Pescoço-CP, Cintura-CC e Quadril-CQ), percentual de gordura corporal através do Índice de Adiposidade Corporal-IAC, volumes e capacidades pulmonares (CVF, VEF1 e VRE) e pressões respiratória estática (PIM e PEM) e dinâmica (VVM). Resultados: O VRE foi o volume mais afetado pela obesidade (apenas 41%predito) e mostrou associação negativa nas relações com todos os marcadores de adiposidade (IMC: r=-0.52; IAC: r=-0.21; CC: r=-0.44; CP: r=-0.25 e CQ: r=-0.28). Há relação inversa entre o percentual de gordura corporal (IAC) com a CVF (r=-0.59), o VEF1(r=-0.56) e o VVM (r=-0.43). As pressões respiratórias são justificadas principalmente pela adiposidade ao redor do pescoço e o IAC. Nossos dados de força muscular respiratória foram melhores associados aos valores de referências sugeridos pelas equações de Harik-Klan et al (1998) para PIM (R²=0.72) e com a equação proposta por Neder et al (1999) para PEM (R²=0.52). Em um modelo de regressão linear, as variáveis de adiposidade não justificam a VVM, já o VEF1 explica 62% da variância da VVM em obesos mórbidos. Conclusão: O percentual da adiposidade corporal e a circunferência do pescoço estão associados com a força muscular e capacidade de gerar fluxo respiratório de obesos mórbidos. Sugerimos a equação elaborada por Harik-Klan et al (1998) para obtenção de valores preditos de PIM e a equação proposta por Neder et al (1999) para valores de normalidade da PEM em sujeitos com obesidade mórbida. Foi possível fornecer uma equação de referência específica para VVM em obesos mórbidos

Avaliação em saúde bucal na perspectiva do usuário: enfoque ao estudo da acessibilidade organizacional

Due to the fact of oral health sector reestructuration within Brazilian public health politics, this work had the object of evaluating, under users point of view, the accessibility to oral health services in Santa Cruz (RN), focusing on the organizational aspect. To achieve this, questionnaires were given to users in their homes, considering the censitary sector. Nine sectors of the urban zone were evaluated, selected by chance, and one from the rural zone, selected by convenience. The sample was composed by 194 users, calculated considering the estimated prevalence of event represented by the indicator I ve never been to the dentist + I ve been to the dentist more than three years ago from the Projeto SB Brasil Report . To complement the results, interviews were made with others actors involved in the process of oral health care: professionals (dentists) and manager (Health Municipal Secretary). From the data obtained it was possible to identify that 12,9% of the population had never visited the dentist, and that the search for the service was not influenced by the users individual and socioeconomics characteristics, excepting the gender. It was verified that 36,1% of the users went to the dentist in less than one year, with the youngests (p<0,05) being among those who went to the dentist more frequently. 63,3% of the interviewed related that they found some kind of difficulty when they search for dentistry services, with the difficulties for schedule, the queues and the long wait among the most cited. It was identified that 43,2% of the users wait three weeks or more for the appointment. It is still pointed out that 71,4% of the interviewed find difficulties to get urgency appointment, the long wait to be attended by the dentist was the most found. 92,9% and 94,1% of the interviewed had never been headed to especialized appointments and complementary exams, respectively. Due to the data founded, it was possible to verify that the accessibility to oral health services in Santa Cruz (RN) is damaged by factors related to the organization of public polices developed, mainly in relation to the working process

Fatores de influência na produção de leite bovino sobre os níveis da contagem bacteriana total

The objective of this study was to evaluate the influence of milking procedures on the levels of total bacterial count (TBC) in bovine milk. In the first study the influences of procedures for hygienic milking, cleaning of milking equipment and milk cooling tanks on the TBC levels were evaluated. Four bulk samples of milk were collected from each tank in eight properties for TBC analysis, employing the flow cytometry method. A questionnaire was applied in each property to assess the current situation of milking procedures on each production system that took part on this research, followed by training of employees in good agricultural practices in the production of milk and monitoring of the TBC measurements. The methodology for analysis of longitudinal data was considered, focusing on random effects models. The results showed that the handling procedures for milking and the cleanliness of the cooling tank contributed to a further reduction in the levels of TBC raw milk cooling tanks. The second study aimed to describe the percentage of the properties that comply with the Normative Instruction Nº 51 (Brazil s IN 51) with regard to total bacterial count (TBC) in bovine milk. The study was conducted from January 2010 to July 2011. Milk samples were collected from the eight properties selected for TBC analysis by the flow cytometry method. Again, on each property a questionnaire was applied to assess the current situation of milking procedures on each production system that took part on this research, followed by training of employees in good agricultural practices in the production of milk and monitoring of the TBC measurements. The methodology of marginal models based on Generalized Estimate Equations (GEEs) was followed in the statistical analysis. The results showed that the handling procedures of the milking and the cleanliness of the cooling tanks contributed to a considerable percentage of the properties that reached the limits of TBC established by IN 51

Dinâmica populacional e alimentar de Stegastes fuscus, (Osteichthyes:pomacentridae) em arrecifes da praia de Búzius, no Rio Grande do Norte

The damselfish, Stegastes fuscus Cuvier, 1830 (Osteichthyes: Perciformes: Pomacentridae), is abundant in the coastal reefs of Búzios Beach, Rio Grande do Norte, Brazil and they play an important role in the reef community ecology. The present study investigated the feeding strategy of this species considering the food habits and morfo-histology of the digestive tract. Influence of the environmental correlates such as temperature, rainfall and luminosity in the tidal rock pools were studied. The fish were captured on a monthly basis from September 2004 to August 2005, during which period 842 individuals of S. fuscus were captured, 125 males, 437 females and 280 individuals without sex identification. The sex ratio observed was 1 M : 3,5 F. The total body length of males varied from 3.6 to 11.3 cm, with a mean of 7.77 cm; that of females varied from 2.9 to 11.4 cm, with a mean of 7.85 cm, and that of sex grouped individuals varied from 2.9 to 11.4 cm, with a mean of 7.83. However, there was no difference between males and females in total body length. This species presented a positive alometric growth and the equations obtained for the relation between body mass and total body length were: Wt =0,0174Lt 3,1123 for males; Wt =0,0137Lt 3,2294 for females and Wt = 0,0148Lt 3.1928 for sex grouped individuals. The relation between total body length and standard length was L t = 1 ,3223Ls + 0,1527 for sex grouped individual s. February to August was associated to a long period of gonadal resting. The fish spawned during January and in September -October. The frequency of fish with empty stomachs occurred during August to December, whereas frequency of fish with food contents i n stomachs occurred during January to July. This species is considered as a preferential herbivore based on the volume of macroalgae in its diet composition. The morfo -histological aspects of S. fuscus confirm herbivory. Among the environmental factors con sidered only rainfall showed a correlation with the feeding habits of this species

A presença da produção científica em psicologia na formação de psicólogos do Rio Grande do Norte

The present research aimed to analyze the presence of national scientific production in undergraduate studies in Psychology of Rio Grande do Norte. Therefore, the bibliographical references contained in education plan of subjects linked to the common center of the courses, which were taught in 2011 in three Psychology courses of the state, were focused. The analysis of the material was based on bibliographical and contextual aspects of the production, such as year, nationality, type of material, authorship (including the link of authors to PPGs), structuring axis of the subject in which it was mentioned, among others. The results showed that the national production is predominant in all courses, and they are, mostly, originated from PPGs of Psychology. Among these, the publications resulted from programs in Southwest, with emphasis to PUC-SP, are recent (mostly from 2000s) and they are predominantly composed by books (organizations and full texts). Regarding the distribution of Psychology PPGs production by the structuring axes, it is observed that it surpasses the foreign production only in axis C (procedures of scientific investigation and professional practice) and axis F (professional practices). Accordingly, it is concluded that Psychology production is found in graduation, sharing space with foreign publications and from other areas of knowledge. On the one hand, this is positive, by taking into account the importance of several foreign works and from other fields to build the knowledge in Psychology; on the other hand, it shows that the production from this area is inserted in graduation in a less significant way than its growth, which points out the existence of gaps in the development of some investigative domains from national Psychology

Craqueamento térmico e termocatalítico do óleo de girassol (Hellianthus annus L.) sobre materiais micro e mesoporosos

Microporous materials zeolite type Beta and mesoporous type MCM-41 and AlMCM-41 were synthesized hydrothermally and characterized by methods of X-ray diffraction, Fourier transform infrared, scanning electron microscopy, surface acidity, nitrogen adsorption, thermal analysis TG / DTG. Also we performed a kinetic study of sunflower oil on micro and mesoporous catalysts. The microporous material zeolite beta showed a lower crystallinity due to the existence of smaller crystals and a larger number of structural defects. As for the mesoporous materials MCM-41 and AlMCM-41 samples showed formation of hexagonal one-dimensional structure. The study of kinetic behavior of sunflower oil with zeolite beta catalysts, AlMCM-41 and MCM-41 showed a lower activation energy in front of the energy of pure sunflower oil, mainly zeolite beta. In the thermal cracking and thermocatalytic of sunflower oil were obtained two liquid fractions containing an aqueous phase and another organic - organic liquid fraction (FLO). The FLO first collected in both the thermal cracking as the thermocatalytic, showed very high level of acidity, performed characterizations of physicochemical properties of the second fraction in accordance with the specifications of the ANP. The second FLO thermocatalytic collected in cracking of sunflower oil presented results in the range of diesel oil, introducing himself as a promising alternative for use as biofuel liquid similar to diesel, either instead or mixed with it

Estudos das interações de quitosana/CTAB/C12E8

Surfactant-polymer interactions are widely used when required rheological properties for specific applications, such as the production of fluids for oil exploration. Studies of the interactions of chitosan with cationic surfactants has attracted attention by being able to cause changes in rheological parameters of the systems making room for new applications. The commercial chitosan represents an interesting alternative to these systems, since it is obtained from partial deacetylation of chitin: the residues sites acetylated can then be used for the polymer-surfactant interactions. Alkyl ethoxylated surfactants can be used in this system, since these non-ionic surfactants can interact with hydrophobic sites of chitosan, modifying the rheology of solutions or emulsions resultants, which depends on the relaxation phenomenon occurring in these systems. In this work, first, inverse emulsions were prepared from chitosan solution as the dispersed phase and cyclohexane as the continuous phase were, using CTAB as a surfactant. The rheological analysis of these emulsions showed pronounced pseudoplastic behavior. This behavior was attributed to interaction of "loops" of chitosan chains. Creep tests were also performed and gave further support to these discussions. Subsequently, in order to obtain more information about the interaction of chitosan with non-ionic surfactants, solutions of chitosan were mixed with C12E8 and and carried out rheological analysis and dynamic light scattering. The systems showed marked pseudoplastic behavior, which became less evident when the concentration of surfactant was increased. Arrhenius and KWW equations were used to obtain parameters of the apparent activation energy and relaxation rate distribution, respectively, to which were connected to the content of surfactant and temperature used in this work

Fatores capazes de influenciar o apoio dos residentes ao desenvolvimento do turismo religioso em Santa Cruz - RN

This study is about the primary stakeholder management - the resident community, given its participation and support for the development of tourism in touristic destinations. It has as a general aim to analyze the factors that are capable to influence the residents‟ support to the development of religious tourism in Santa Cruz, RN, and the existing interrelationships between factors. In order to achieve this objective, it was necessary to use exploratory and descriptive research, followed by a quantitative approach through questionnaires with 422 residents of Santa Cruz -RN. The study was based on the variables relationship model proposed by Nunkoo and Ramkissoon (2012), it was also used the technique of Structural Equation Modeling - SEM, aiming to explain the relationships between the constructs studied. The results found on the survey suggest that the more residents realize the benefits generated by tourism, as well as trust in government actors in charge of tourism development, the more there will be a propensity to support the development of religious tourism. This result is similar to the one found in the study of Nunkoo and Ramkissoon (2012). We conclude that the structural model that best represents the reality of Santa Cruz -RN is composed of the factors: benefits, costs, and confidence in governmental actors, which are able to influence the support of Santa Cruz‟s residents for the development of religious tourism. It is also noteworthy that it was found a highly significant connection between the factors benefits perceived from tourism and confidence in governmental actors and between both of them, the political support for tourism

Fatores que afetam o apoio de residentes ao desenvolvimento do turismo em sítios arqueológicos: um estudo no Seridó Potiguar

The tourist activity , which appropriates spaces and natural , cultural , social and economic scenarios in a given locality , requires a model of integrated development necessarily reconciling the support of residents. In this perspective , this study aims to analyze the factors influencing the support of residents in tourism development in archaeological sites , specifically in the two counties of Parelhas and Carnaúba dos Dantas , in Rio Grande do Norte, in the region of Seridó Potiguar as well as the interrelationship existing between these factors . To achieve the proposed objective of the research , a descriptive -exploratory and quantitative study based on the study of Nunkoo and Hamkisson (2012 ) , using the technique of Structural Equation Modeling - SEM to explain the relationships of the constructs used in this research. Data collection was performed during the periodof May 2013 to July 2013. Among other studies, results indicate that , for the profile of the interviewees used , the higher the confidence of the community residing in the government agencies responsible for, the largest tourism will support the resident to the tourism development and that this supply relationship institutions and government agencies an opportunity to enhance their development strategies and social thinking of the resident agent of tourism . It was also found that the analysis model proposed has a better structural relationship when used interviewees who have knowledge about the activities in the archaeological sites , then suggesting the need for further research on the effect of the level of knowledge of the interviewee on the object and support of residents to tourism development

Simulação de Fluxo no Meio Poroso Utilizando o Fluent

The complexity of the Phenomenon of fluid flow in porous way causes a difficulty in its explicit description. Different in the cases where the flow is given through a pipe, where it is possible to measure the length and diameter of the pipe and to determine their ability to flow as a function of pressure, which is a complicated task in porous way. However, we try to approach clearly the equations used to conjecture the behavior of fluid flow in porous way. We made use of the Gambit to create a fractal geometry with the fluent we give the contour´s conditions we would want to analyze the data. The triangular mesh was created; it makes interactions with the discs of different rays, as barriers putted in the geometry. This work presents the results of a simulation with a flow of viscous fluids (oilliquid). The oil flows in a porous way constructed in 2D. The behavior evaluation of the fluid flow inside the porous way was realized with graphics, images and numerical results used for different datas analysis. The study was aimed in relation at the behavior of permeability (k) for different fractal dimensions. Taking into account the preservation of porosity and increasing the fractal distribution of the discs. The results showed that k decreases when we increase the numbers of discs, although the porosity is the same for all generations of the first simulation, in other words, the permeability decreases when we increase the fractality. Well, there are strong turbulence in the flow each time we increase the number of discs and this hinders the passage of the same to the exit. These results permitted to put in evidence how the permeability (k) is affected in a porous way with obstacles distributed in a diversified form. We also note that k decreases when we increase the pressure variation (P) within geometry. So, in front of the results and the absence of bibliographic subsidies about other theories, the work realized here can possibly by considered the unpublished form to explain and reflect on how the permeability is changed when increasing the fractal dimension in a porous way

Controlador adaptativo backstepping a estrutura variável

Neste trabalho, um controlador adaptativo backstepping a estrutura variável (Variable Structure Adaptive Backstepping Controller, VS-ABC) é apresentado para plantas monovariáveis, lineares e invariantes no tempo com grau relativo unitário. Ao invés das tradicionais leis integrais para estimação dos parâmetros da planta, leis chaveadas são utilizadas com o objetivo de aumentar a robustez em relação a incertezas paramétricas e distúrbios externos, bem como melhorar o desempenho transitório do sistema. Adicionalmente, o projeto do novo controlador é mais intuitivo quando comparado ao controlador backstepping original, uma vez que os relés introduzidos apresentam amplitudes diretamente relacionadas com os parâmetros nominais da planta. Esta nova abordagem, com uso de estrutura variável, também reduz a complexidade das implementações práticas, motivando a utilização de componentes industriais, tais como, FPGAs (Field Programmable Gate Arrays ), MCUs (Microcontrollers) e DSPs (Digital Signal Processors). Simulações preliminares para um sistema instável de primeira e segunda ordem são apresentadas de modo a corroborar os estudos. Um dos exemplos de Rohrs é ainda abordado através de simulações, para os dois cenários adaptativos: o controlador backstepping adaptativo original e o VS-ABC

Controlador adaptativo backstepping a estrutura variavel com Observadores de estado

This research aims at developing a variable structure adaptive backstepping controller (VS-ABC) by using state observers for SISO (Single Input Single Output), linear and time invariant systems with relative degree one. Therefore, the lters were replaced by a Luenberger Adaptive Observer and the control algorithm uses switching laws. The presented simulations compare the controller performance, considering when the state variables are estimated by an observer, with the case that the variables are available for measurement. Even with numerous performance advantages, adaptive backstepping controllers still have very complex algorithms, especially when the system state variables are not measured, since the use of lters on the plant input and output is not something trivial. As an attempt to make the controller design more intuitive, an adaptive observer as an alternative to commonly used K lters can be used. Furthermore, since the states variables are considered known, the controller has a reduction on the dependence of the unknown plant parameters on the design. Also, switching laws could be used in the controller instead of the traditional integral adaptive laws because they improve the system transient performance and increase the robustness against external disturbances in the plant input