Efeito do campo elétrico em nanocones formados por aln e BN: um estudo por primeiros princípios

The development of computers and algorithms capable of making increasingly accurate and rapid calculations as well as the theoretic foundation provided by quantum mechanics has turned computer simulation into a valuable research tool. The importance of such a tool is due to its success in describing the physical and chemical properties of materials. One way of modifying the electronic properties of a given material is by applying an electric field. These effects are interesting in nanocones because their stability and geometric structure make them promising candidates for electron emission devices. In our study we calculated the first principles based on the density functional theory as implemented in the SIESTA code. We investigated aluminum nitride (AlN), boron nitride (BN) and carbon (C), subjected to external parallel electric field, perpendicular to their main axis. We discuss stability in terms of formation energy, using the chemical potential approach. We also analyze the electronic properties of these nanocones and show that in some cases the perpendicular electric field provokes a greater gap reduction when compared to the parallel field

Investigando o campo magnético das estrelas análogas e gêmeas solares através da espectropolarimetria

This study proposes an observing program focused on the investigation of the stellar magnetism and dynamo evolution in cool active solar-like stars. More mainly in the solar analogs and twins. Observations of stars of our base were carried out with two spectropolarimeter (ESPaDOnS@CFHT and NARVAL@TBL). The analyse of stars in stage different allows an understanding of the dependence of magnetic activity on basic stellar parameters such as rotation, mass, age and depth of the convection zone. This study provides measures necessary for testing dynamo theories. The 65 targets for this project are solar type stars with mass spanning from 0:9 M=Mfi 1:075 solar masses and at different evolutionary stages. Our two main science objectives were, (i) To determine how the magnetic field evolved from the ZAMS to the TO (turn off) for stars with 0:9 M=Mfi 1:075; (ii) To determine the impact of convective depth and rotation on magnetic of cool stars of solar type. The main result from this study was the characterization of the dependence of magnetic field intensity as function of age, Rossby number and the convective zone deepening. This context, the availability of ESPaDOnS and NARVAL opens an exceptional possibility to study the magnetic properties of Sun-like stars by means of spectropolarimetric observations

Orientação de falhas presentes em testemunhos de sondagens do campo de Xaréu/bacia do Ceará

A research project is being developed by PPGG/UFRN and PETROBRAS in the Xaréu Oil Field located in Ceará Basin, Northeastern Brazil. The objective of the research is to characterize a fractured carbonate reservoir, the Trairi Limestone, in order to drill a borehole with two horizontal legs taking advantage of the natural fracture system to enhance the oil recovery. The present master thesis is part of this research and its contribution is to estimate fault orientation from unoriented cores, using the method proposed by Hesthammer & Henden (2000). In order to orient a fault cutting a bed observed in the core, the bed should be previously oriented. As additional constraint to orient the bed, we use regional bedding orientation obtained from structure maps of Trairi Limestone. Because the number of cores drilled from the Trairi Limestone was too small, we analyzed all cores from the field. As geologic constraint, we admit that all faults were formed as result of the South America and Africa separation, in the context of a regional dextral strike-slip fault formation. In this context, secondary faults are manly T and R faults according Riedel s classification. We analyzed 236.5 m of cores. The dip of bedding varies from 0o to 8o, being the most frequent value equal to 2o. We interpret this result as evidence that the deformation process was manly ruptil. 77 faults were identified in the cores. These faults strike manly to NW and NE with dips, in general, inside the interval 700 - 900. We suggest that the horizontal legs of the borehole should be oriented to NW and NE in order to improve the probability of intercepting open fractures and faults

Geoprocessamento de dados meteo-oceonográficos (cor do oceano e temperatura da superfície do mar) aplicado ao monitoramento ambiental na costa setentrional do Rio Grande do Norte

Orbital remote sensing has been used as a beneficial tool in improving the knowledge on oceanographic and hydrodynamic aspects in northern portion of the continental shelf of Rio Grande do Norte, offshore Potiguar Basin. Aspects such as geography, temporal and spatial resolution combined with a consistent methodology and provide a substantial economic advantage compared to traditional methods of in situ data collecting. Images of the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor onboard NASA's AQUA satellite were obtained to support systematic data collections related to the campaign of environmental monitoring and characterization of Potiguar Basin, held in May 2004. Images of Total Suspension Matter (TSM) and values of radiance standard were generated for the calculation of concentrations of total suspension matter (TSM), chlorophyll-a and sea surface temperature (SST). These data sets were used for statistical comparisons between measures in situ and satellite estimates looking validate algorithms or develop a comprehensive regional approach empirically. AQUA-MODIS images allowed the simultaneous comparison of two-dimensional water quality (total suspension matter), phytoplankton biomass (chlorophyll-a) variability and physical (temperature). For images of total suspension matter, the generated models showed a good correlation with the field data, allowing quantitative and qualitative analysis. The images of chlorophyll-a showed a consistent correlation with the in situ values of concentration. The algorithms adjusted for these images obtained a correlation coefficient fairly well with the data field in order that the sensor can be having an effect throughout the water column and not just the surface. This has led to a fit between the data of chlorophyll-the integration of the average sampling interval of the entire water column up to the level of the first optical depth, with the data generated from the images. This method resulted in higher values of chlorophyll concentration to greater depths, due to the fact that we are integrating more values of chlorophyll in the water column. Thus we can represent the biomass available in the water column. Images SST and SST measures in situ showed a mean difference DT (SST insitu - SST sat) around -0.14 ° C, considered low, making the results very good. The integration of total suspension matter, chlorophyll-a, the temperature of the sea surface (SST) and auxiliary data enabled the recognition of some of the main ways to fund the continental shelf. The main features highlighted were submerged canyons of rivers Apodi and Açu, some of the lines and beachrocks reefs, structural highs and the continental shelf break which occurs at depths around -60 m. The results confirmed the high potential for use of the AQUA-MODIS images to environmental monitoring of sea areas due to ease of detection of the field two-dimensional material in suspension on the sea surface, temperature and the concentration of chlorophyll-a

Vulnerabilidade ambiental da zona costeira de Pititinga, Rio do Fogo, Rio Grande do Norte

This work presents a study on the environmental vulnerability of the coastal region of Pititinga, Rio do Fogo/RN. The coastal erosion of Pititinga beach was analyzed and considerated as one more process that produces environmental vulnerability in the area of study, taking into account its human and natural environment and establishing the relation between them, to understand the arrangement that produced its spatial configuration. The natural environment was expressed by thematics maps with geology, geomorphology, vegetation and soil themes, while the human environment was expressed by the use and occupation of the soil map. The coastal erosion was put in an erosion vulnerability map. The methodological procedure to generate the thematics maps, vulnerability maps and of the erosion coastal involved the bibliographic research, field visits with check-list form fill, collect and analysis of sediment sample, photo-interpretation techniques, integration of the information in a database, data store and spatial analysis in a Geographic Information System (GIS) ambient. The natural vulnerability map shows a predominancy of environments with low (29,6%) or medium (42,4%) vulnerability, pointed the frontal and mobile dune as the areas with the highest vulnerability. The environmental vulnerability map, presents a predominancy of environments with low vulnerability (53,8%), with the high vulnerability concentrated on Pititinga community. The coastal erosion vulnerability presented distinct behaviors on three sections among the coastal line according each one characteristics. Where there are frontal and transgressive dunes, vulnerability are, generally, medium or low, respectively, and in the absence of them, as what occurs in Pititinga community, the vulnerability is predominately very high

Geologia e paleontologia de depósitos fossilíferos pleistocênicos do Rio Grande do Norte

This study deals with origin, sedimentary filling and fossil content of three tanks situated at Antônio Martins, Barcelona, Rui Barbosa, and Apodi counties, Rio Grande do Norte State. In addition, fossil materials from the Câmara Cascudo Museum - UFRN - Fundação Amigos do Lajedo Soledade - FALS, and from private ownership were investigated. The following families were identified: Megatberiidae, Gomphotheriidae, Mylodontidae, Equidae, Felidae, Canidae, Hydrochoeridae, Camelidae, Cervidae, Dasypodidae, Glyptodontidae, Macraucheniidae, Toxodontidae, and an undetermined Edentata Pilosa. The megafauna analysis indicated that herbivorc families occur mainly in tanks, whereas carnivore families occur in a vast proportion in an investigated ravine. Taphonomie analyses were limited to physical features because the vast majority of fossils were previously colleted without appropriate care for this kind of study. The main fossization processes were identified during diagenetie investigation. Permineralization is the most important process and replacement is the secondary one during fossilization. The study concluded that paleoenvironmental conditions during the late Pleistocene were more humid than the current one. Tropical savana, characterized by fields and cerrados , was the dominant vegetation

Caracterização de reservatórios siliciclásticos neoaptianos: um estudo do membro carmópolis no campo de Camorim, sub-bacia de Sergipe, Brasil

The Camorim Oilfield, discovered in 1970 in the shallow water domain of the Sergipe Sub-basin, produces hydrocarbons from the Carmópolis Member of the Muribeca Formation, the main reservoir interval, interpreted as siliciclastics deposited in an alluvial-fluvial-deltaic context during a late rifting phase of Neoaptian age, in the Sergipe-Alagoas Basin. The structural setting of the field defines different production blocks, being associated to the evolution of the Atalaia High during the rift stage and subsequent reactivations, encompassing NE-SW trending major normal faults and NWEW trending secondary faults. The complexity of this field is related to the strong facies variation due to the interaction between continental and coastal depositional environments, coupled with strata juxtaposition along fault blocks. This study aims to geologically characterize its reservoirs, to provide new insights to well drilling locations in order to increase the recovery factor of the field. Facies analysis based on drill cores and geophysical logs and the 3D interpretation of a seismic volume, provide a high resolution stratigraphic analysis approach to be applied in this geodynamic transitional context between the rift and drift evolutionary stages of the basin. The objective was to define spatial and time relations between production zones and the preferential directions of fluid flow, using isochore maps that represent the external geometry of the deposits and facies distribution maps to characterize the internal heterogeneities of these intervals, identified in a 4th order stratigraphic zoning. This work methodology, integrated in a 3D geological modelling process, will help to optimize well drilling and hydrocarbons production. This methodology may be applied in other reservoirs in tectonic and depositional contexts similar to the one observed at Camorim, for example, the oil fields in the Aracaju High, Sergipe Sub-basin, which together represent the largest volume of oil in place in onshore Brazilian basins

Caracterização geológica tridimensional e monitoramento de dunas no litoral oriental do Rio Grande do Norte

This work presents geophysical and geological results obtained in a dunefield located in the east coast of Rio Grande do Norte State, with the aim to recognize the aeolian body depositional geometries to a future geologic modeling of the aeolian petroliferous reservoirs. The research, which was done in blowouts region situated at Nisia Floresta Municipally, included the characterization of external geometries with GPS and internal geometry analysis by GPR. Data was integrated in GoCAD software, where it was possible the three-dimensional characterization and interpretation of the studied deposits. The interpretation of GPR profiling allowed identifying: First-order bounding surfaces that separated the aeolian deposits of the Barreiras Formation rocks; Second-order bounding surfaces, which limit dune generations and Third-order bounding surfaces, a reactivation surface. This classification was based and adapted by the Brookfield (1977) and Kocurek (1996) propose. Four radarfacies was recognized: Radarfacies 1, progradational reflectors correlated to foresets of the dunes, Radarfacies 2, plain parallels reflectors related to sand sheets, Radarfacies 3, plain parallels reflectors associated to reworking of the blowout dune crest and Radarfacies 4, mounded reflectors associated to vegetated mound of sand or objects buried in subsurface. The GPR and GPS methods was also employed to the monitoring of dunefields susceptible to human activities in Buzios Beach, where the constructions along the blowout region and the tourism are changing the natural evolution of the deposits. This fact possibly to cause negative impacts to the coastal zone. Data obtained in Dunas Park, a unit environmental conservation, was compared with information of the Buzios Beach. There is a major tendency of erosion in Buzios, specifically in blowout corridor and blowout dune

Mapa dos programas sociais: transferência de renda e dinâmicas sociais no Rio Grande do Norte (2000-2007)

The question of evaluating the fight against poverty in a given society is very complex task, considering the range of factors that permeate, such as education, culture and economy itself. Come hence the relevance of the theme and its constant presence in discussions on the fruits of public policies, institutional structure and economic development which are the guiding elements of this work, and noted that seeks to highlight the social demographics and most important, the most significant trends and issues pertaining to her. The assessment was initially made in all the municipalities of Rio Grande do Norte doing a verticalilzação to the municipalities Caicó, Pau dos Ferros, Ipueira and Taboleiro Grande. Highlighting the role of a social policy through government programs, such as the Bolsa Familia Program (PBF), which creates the possibility of changes in the socio demographic profile given the importance that the action of this public policy has in shaping the regional economic reality As well as social programs and actions of the government here reported that generate mobility of people and new social demands, such as rural retirements, the benefit of continuing provision (BPC), the Program for the Eradication of Child Labor (PETI) that put on the market of population living on the margins of various forms of consumption. Accordingly, the socio economic profile of the state shows a significant improvement in their social indicators, vital education and redistribution of income, due to the significant improvement in life expectancy in the fall of school drop-out rate and the drop in indicators of Proportion Poor and destitute of the state. Where the fall in the proportion of poor and indigent is strongly associated with an increase in income, from social programs. With this transfer and redistribution of income can be gauged that occurs a strengthening of local economies and an engagement of families with the conditionalities of social programs and PETI Bolsa Familia. Our research concludes that simply raising the rents caused by transfers, presents relevant impacts on the education of young people in beneficiary families. There is no doubt that the programs of transfer income, no facing the social field, representing a mechanism to decrease the most perverse ills of poverty, social and economic inequality that is hungry. For a significant portion of the Brazilian population living below the poverty line, programs for the transfer of income are expressed directly in improving the material conditions of life and indirectly in improving self-esteem of women and all family members receiving encouraging yet the integration family. Experiments have shown that improvements in health and nutrition can be obtained through the implementation of adequate social policies like the programs of transfer income, while social inclusion and economic does not become full

O reassentamento dos refugiados colombianos e palestinos no estado do Rio Grande do Norte

Since the second semester of 2004, the first refugees guided by ACNUR arrived at Potiguar s territory. Then we follow closely, with other local actors, the implementation and development of this innovative action, namely the resettlement of those refugees in Rio Grande do Norte. To accomplish this, we consider the concepts of territory, dispossession, repossession and international migration. The state of Rio Grande do Norte is a pioneer in the Northeast, in this type of action, since, before this experience, just Rio Grande do Sul and São Paulo were engaged in this kind of action. Therefore, this paper analyzes the process of resettlement of refugees, fulfilled in Rio Grande do Norte, between 2004 and 2005. The research broaches the regards that resulted in departure of these refugees from their respective territories (Colombia and Palestine) as well as the characteristics and prospects of the areas that hosted the refugees (Natal, Lajes e Poço Branco). Finally, the work deals with the results achieved afield, through interviews and photographic record, near by refugees

Indústria informal de confecções e mercado de trabalho :um estudo sobre a grande Natal (1977-2003)

The process of globalization which has characterized today s Brazilian economic development is determining in the restructuring of productive capital, influencing the development of an economic model, founded on greater competition and use of technology. As a consequence of that, there has been a certain disorganization of the economy, the growth of social inequalities and the lack of structuring of the labor market and the social security system. This has favored a rapid growth of the urban informal economy in Brazil. In Rio Grande do Norte state, the Greater Natal area is the main production center. This is where this study found 58 informal textile industries. In the research, the organizational structure of these industries, characterized by intensive use of labor vis-à-vis the use of capital, problems with putting production in the market place, although links with the formal sector were evident, is analysed. The research also focuses on the relationship labor x capital, the nature and volume of the industrial activity in the 58 industries, their proprietors and 120 employees

A dinâmica territorial da Assembléia de Deus do seridó do Rio Grande do Norte

In the norte-rio-grandense backwoods is possible to join to the power forms both political and economical ones, religious groups keeping under your control areas, people and flow of them, as well as settling new places of acts. That control refers to a field of power delimited by space, in other words, it refers to a territory marked and planned to reproductive intentions on the space. In relation to the religious pluralism, the Assembly of God church, in your territorial dynamics, has been standing out by the strategies of delimitation and space increase which by a constant territorial division process (1943-2010) managed to widen material and symbolic scale of its power for all cities of the Rio Grande do Norte backwoods. The Assembly of God church as the greatest Pentecostal denomination of Brazil was formed in the Rio Grande do Norte Seridó, following a ecclesiastical and governmental model divided into three ecclesiastical fields hosted in those following cities: Caicó, Currais Novos and Parelhas. Those headquarters interlink a limited number of churches through normative codes, which they express a functional dimension (bureaucratic) and in another symbolic one (charismatic) in an only field of territorial control. In this manner, the maintenance of the territorial power in the Assembly of God church is done by a charismatic-bureaucratic administration, expressed in the interdependent of material and abstract mechanisms. The believers permanent contact toward those mechanisms of institutional control revealed territorial identities which causes a feeling of property of the believer as much to the Pentecostal belief system as to community of the Assembly of God church. Considering new possibilities of articulation of the Rio Grande do Norte backwoods towards others territories more multiple, culturally, noticed cultural adjustments and revaluation at themselves. In relation to the territory of the Assembly of God church this one has exposed itself defensive faced with that cultural hybridization tendency, resisting a closer dialogue to new symbolic elements, mainly those came from the multifaceted neo-pentecostal movement. Unlike more open and flexible churches towards others significant systems, The Assembly of God church tries to reinforce the boundaries of its territory considering by the orthodoxy of its routine and customs

Avaliação do pré-natal na atenção primária à saúde no Rio grande do Norte: visão das usuárias

ABSTRACT This study aimed to evaluate the quality of prenatal Primary Care in Rio G rande do Norte, Brazil in 2012 under the program Improving Access and Quality of Primary Care. The study was cross - sectional, quantitative. Included 156 mothers of children under 2 years who received prenatal care at the health evaluated. We applied a ques tionnaire on profile, minimum queries, regularity of attendance, laboratory tests, vaccination, participation in educational activities, guidance received, clinical and obstetric procedures and prescription Ferrous sulphate and folic acid. The descriptive analysis of the criteria used Humanization Program Prenatal and Birth. The results showed that 92% of mothers had six or more visits; 85% with the same care was professional; 94% subsequent appointments scheduled. As for tests and procedures the percentage s were: Urine 98%; HIV - 96%; VDRL and 88%; 91% glucose; tetanus vaccination 93%; educational groups 56% with 36% participation, knowledge of the delivery location and 59% achievement breast exam 65%, 33% and preventive gynecological 43%; 98% supplemented wi th 96% Ferrous Sulfate and Folic Acid. It was concluded that there were advances in Rio Grande do Norte concerning assistance and there are weaknesses in the educational practices and conducting some minimal clinical examinations.

Medida de uma codificação de estímulos sonoros por potenciais pós-sinápticos e potenciais de campo local usando teoria da informação

Coding process is a fundamental aspect of cerebral functioning. The sensory stimuli transformation in neurophysiological responses has been a research theme in several areas of Neuroscience. One of the most used ways to measure a neural code e ciency is by the use of Information Theory measures, such as mutual information. Using these tools, recent studies show that in the auditory cortex both local eld potentials (LFPs) and action potential spiking times code information about sound stimuli. However, there are no studies applying Information Theory tools to investigate the e ciency of codes that use postsynaptics potentials (PSPs), alone and associated with LFP analysis. These signals are related in the sense that LFPs are partly created by joint action of several PSPs. The present dissertation reports information measures between PSP and LFP responses obtained in the primary auditory cortex of anaesthetized rats and auditory stimuli of distinct frequencies. Our results show that PSP responses hold information about sound stimuli in comparable levels and even greater than LFP responses. We have also found that PSPs and LFPs code sound information independently, since the joint analysis of these signals did neither show synergy nor redundancy.

O programa de aquisição de alimentos (PAA) e as transformações socioterritoriais no Rio Grande do Norte

The Acquisition Food Program (Programa de Aquisição de Alimentos – PAA) is one of the governmental public politics proposed, in the year of 2003, that has the focus in the family-run farm in Brazil. This Program has as objectives: commercialize the familyrun farm products, bought by the government agencies; to encourage production, and promoting actions that improve quality food of people facing starving risk. This Program has been working, to some extent, as complement to the Program of family-run farm Enhancement (PRONAF). The present study has as its focus to analyse the social territorials changes observed in the state of Rio Grande do Norte, as a result of the PAA implementation. In this sense, it was promoted a discussion between territory and rules. I this work, public politics are understood as rules. This procedure was important in order to understand how the rules have influenced territorial changes, creating new social and territorial relations. In the research process was used scientific and institutional texts on the subject. It was applied a quiz with 97 PAA’s supplying farmers, and interviews were done with the Program managers in Federal (MDA), State (CONAB and EMATER) and municipal (local office of EMATER and Departments of Agriculture) levels. Social public politics were also analyzed with the aim of understand the context where PAA is situated in relation with the public politics directed to familyrun farm as a whole since 1980, within new Brazilian democratization process. With the information collected in the field, plus the secondary data, maps, charts, tables and cartograms were made. With all of this, a socio-economical profile of the family-run farm in the Rio Grande do Norte was traced, as well as the included in this research. Before this picture, we concluded that PAA indeed represents a forward in public politics directed to family-run farm. However, in spite of the importance of the Program for the family-run farmers to come of age, but in order to the rural and family-run farm reality in the Rio Grande do Norte come to present meaningful changes much still remain to be done.