36 resultados para Transparent Conductors
em Universidade Federal do Rio Grande do Norte(UFRN)
Resumo:
Top-down (grazing) and bottom-up (nutrient, light) controls are important in freshwater ecosystems regulation. Relative importance of these factors could change in space and time, but in tropical lakes bottom-up regulation has to been appointed as more influent. Present study aimed to test the hypothesis that phytoplankton growths rate in Armando Ribeiro reservoir, a huge eutrophic reservoir in semi-arid region of Rio Grande do Norte state, is more limited by nutrient available then zooplankton grazing pressure. Bioassay was conduced monthly from September (2008) to August (2009) manipulating two levels of nutrients (with/without addition) and two level of grazers (with/without removal). Experimental design was factorial 2X2 with four treatments (X5), (i) control with water and zooplankton from natural spot ( C ), (ii) with nutrient addition ( +NP ), (iii) with zooplankton remove ( -Z ) and (iv) with zooplankton remove and nutrient addition ( -Z+NP ). For bioassay confection transparent plastic bottles (500ml) was incubate for 4 or 5 days in two different depths, Secchi`s depth (high luminosity) and 3 times Secchi`s depth (low luminosity). Water samples were collected from each bottle in begins and after incubates period for chlorophyll a concentration analysis and zoopalnktonic organisms density. Phytoplankton growths rates were calculated. Bifactorial ANOVA was performance to test if had a significant effect (p<0,005) of nutrient addition and grazers remove as well a significant interaction between factors on phytoplankton growths rates. Effect magnitude was calculated the relative importance of each process. Results show that phytoplankton growth was in generally stimulated by nutrient addition, as while zooplankton remove rarely stimulated phytoplankton growth. Some significant interactions happening between nutrient additions and grazers remove on phytoplankton growth. In conclusion this study suggests that in studied reservoir phytoplankton growth is more controlled by ascendent factors than descendent
Resumo:
The Tungsten/copper composites are commonly used for electrical and thermal objectives like heat sinks and lectrical conductors, propitiating an excellent thermal and electrical conductivity. These properties are dependents of the composition, crystallite size and production process. The high energy milling of the powder of W-Cu produces an dispersion high and homogenization levels with crystallite size of W very small in the ductile Cu phase. This work discusses the effect of the HEM in preparation of the W-25Cu composite powders. Three techniques of powder preparation were utilized: milling the dry with powder of thick Cu, milling the dry with powder of fine Cu and milling the wet with powder of thick Cu. The form, size and composition of the particles of the powders milled were observed by scanning electron microscopy (SEM). The X-ray diffraction (XRD) was used to analyse the phases, lattice parameters, size and microstrain of the crystallite. The analyse of the crystalline structure of the W-25Cu powders milled made by Rietveld Method suggests the partial solid solubility of the constituent elements of the Cu in lattice of the W. This analyse shows too that the HEM produces the reduction high on the crystallite size and the increase in the lattice strain of both phases, this is more intense in the phase W
Resumo:
The Wireless Sensor Networks (WSN) methods applied to the lifting of oil present as an area with growing demand technical and scientific in view of the optimizations that can be carried forward with existing processes. This dissertation has as main objective to present the development of embedded systems dedicated to a wireless sensor network based on IEEE 802.15.4, which applies the ZigBee protocol, between sensors, actuators and the PLC (Programmable Logic Controller), aiming to solve the present problems in the deployment and maintenance of the physical communication of current elevation oil units based on the method Plunger-Lift. Embedded systems developed for this application will be responsible for acquiring information from sensors and control actuators of the devices present at the well, and also, using the Modbus protocol to make this network becomes transparent to the PLC responsible for controlling the production and delivery information for supervisory SISAL
Resumo:
Ionic liquids (ILs) are organic compounds liquid at room temperature, good electrical conductors, with the potential to form as a means for electrolyte on electrolysis of water, in which the electrodes would not be subjected to such extreme conditions demanding chemistry [1]. This paper describes the synthesis, characterization and study of the feasibility of ionic liquid ionic liquid 1-methyl-3(2,6-(S)-dimethyloct-2-ene)-imidazole tetrafluoroborate (MDI-BF4) as electrolyte to produce hydrogen through electrolysis of water. The MDI-BF4 synthesized was characterized by thermal methods of analysis (Thermogravimetric Analysis - TG and Differential Scanning Calorimetry - DSC), mid-infrared spectroscopy with Fourier transform by method of attenuated total reflectance (FTIR-ATR), nuclear magnetic resonance spectroscopy of hydrogen (NMR 1H) and cyclic voltammetry (CV). Where thermal methods were used to calculate the yield of the synthesis of MDI-BF4 which was 88.84%, characterized infrared spectroscopy functional groups of the compound and the binding B-F 1053 cm-1; the NMR 1H analyzed and compared with literature data defines the structure of MDI-BF4 and the current density achieved by MDI-BF4 in the voltammogram shows that the LI can conduct electrical current indicating that the MDI-BF4 is a good electrolyte, and that their behavior does not change with the increasing concentration of water
Resumo:
Several pharmaceutical products have been developed in recent years aiming to enhance the treatment of diseases by increasing the effectiveness of drugs. Many of these new products are based on new drug delivery systems. Among these, microemulsions, which were first studied in 1943 by Hoar and Schulman, is of great interest. Microemulsion can be defined as a thermodynamically stable, isotropic, translucent and transparent system of two immiscible liquids stabilized by a surfactant film located in the oil / water interface. The aim os this work was the incorporation of Amphotericin B and Simvasatin to a microemulsion system and analyzes its physicochemical properties and their therapeutical activity when incorporated into this system. Some very promising results were achieved as the reduction of the toxicity and maintenance of the efficacy of the Amphotericin B incorpored into a microemulsion, which was demonstrated in the in vitro pharmacotoxicological study. As for the incorporation of Simvastatin in microemulsion, it was observed a significant improvement in the potential antiinflammatory and anti-infective properties when the system was use to treat infected wounds (simvastatin pleiotropic effects). Therefore, it can be concluded that the incorporation of these drugs into microemulsion system reveal the potential of microemulsions as a promising and novel dosage form, qualifying them for future trials in order to make them available in the pharmaceutical market
Resumo:
The goal of this study is to investigate about the existence or absence of environmental dumping in the production of fuel ethanol in Brazil, as well as identifying the reasons why the figure of ecological dumping is pernicious to the principles enumerated in constitutional economic order, in particular the principle of free competition. In the twenty-first century environmental issues gained momentum and importance in these terms, which was seen as a mere fallacy given the concern of governments of various countries, after all, environmental protection shows up as the only means of bringing about the maintenance of life at planet. Indeed, it is essential to halt the drastic effects of climate change, and think fast and efficient solutions. Undoubtedly, the contemporary requirements that resulted in the transition to a new economy brings with it the duty of enterprise search for sustainability, and this behavior can not be passive, otherwise it is imperative to work hard and incessant economic agents, even if initially costs are high, this step will ensure a production accountable, transparent and free from accusations of environmental degradation. It is also intended to study the importance of the sector not only as a source of economic growth, but mainly, its contribution to national development, without forgetting that this is devoted in the Constitution of 1988 as one of the objectives of the Federative Republic of Brazil. In fact, the criticism most common perceptions about the production of biofuels, said the interests of the countries producing them in large scale, will eventually generate a exhaustion of soil and a significant increase in food prices. However, the ethanol produced in Brazil is unique in that it is produced from cane sugar, a product is not intended for human or animal, not to mention that the recovery of land just to the rotation with the planting other cultures. It is expected that environmental certifications are useful to demonstrate the quality of ethanol for export and to refute unfounded criticism. Finally, this study will be analyzed further solutions for the plants to develop an economic activity without damaging the environment and in compliance with Brazilian law
Resumo:
This essay analyzes tax incentives concepts and existing discussions on national and foreing doctrine, especially in countries that influence our legal culture, such as Germany, United States of America, Spain, Italy and England, providing a detailed study about the requirements that must be observed to ensure that there be a legitimate concession of the same. All this using as argument the Constitutional Charter and the development of the Law, mainly through the principle of objective good faith, which acts as the limiting principle of administrative discretion in granting such tax incentives, as well as creative element of the new duties for the public managers in order to be more effective, efficient and transparent compliance with the pact between the government and society and the objectives pursued by the last. Always chasing a strong argument through a broad historical and philosophical analysis of the institutes discussed. Thus, through studies that reveal the necessary incidence of objective good faith in granting tax incentives to achieve the constitutional purposes, this work does not merely disclose what is wrong, but provides solutions to modify reality hitherto existing, ie, introduces ways to reduce the encumbrance of the odious and ineffective tax incentives in society and to redirect these values unjustly destinated for obscure interests to achieve the real reasons for the existence of tax incentives, especially economic development through the reduction of regional and social inaqualities and poverty eradication
Resumo:
This work focuses on the educational policies, on the necessity of adopting new models of administration of the education, as well as the implementation of reforms in this filed during the 1990 s. It analyzes the strategies of decentralization of the education in Rio Grande do Norte, disclosing practices conceived in the governmental plans and programs. It also aims to evidence the aspects of the decentralization proposed in the educational system management model, adopted by the Department of Education and Culture of Rio Grande do Norte from 1995 to 1999. Bibliographic researches and documental analysis were used as sources and semi-structured interviews were held in order to collect data. This work also highlights the concepts of participation, autonomy and democratic management intrinsic to the process of decentralization in the education field. It is clear that decentralization, as the vector of democracy, requires not only certain conditions that assure the universal access to the necessary information, but also that all segments of the institution have a voice in the collegiates and that the management and decision-making processes be transparent. This analysis reveals the importance of creating means to promote autonomy, participation and democratic management in order to consolidate a decentralized system. It is also clear that these mechanisms have been proposed in a vague way by the governmental guidelines, which makes it harder to consolidate a democratic management model. Having this perspective as a parameter, it is possible to realize that the adoption of a management model prompted by the law hasn t established effective means of participation that, consequently, should provide decision centralizers which opposed to the democratic actions
Resumo:
Exploratory, descriptive and quantitative study with prospective data, performed in the Mobile Emergency Care Service in the metropolitan region of Natal/RN, in order to identify the knowledge of the multidisciplinary team about the rules of standard precautions and worker safety, to identify occupational hazards peculiar to the activities of this service; characterize work-related accidents (WRA) and know the procedures adopted after each WRA. The population consisted of 162 professionals and data were collected between the months of November and December 2010. As for personal and professional characteristics, of the 162 professional, 12,96% were physicians; 6,79%, nurses; 33,95%, nursing technicians, 46,29%, conductors; 74,70% were male; 43,21% were between 31 and 40 years old; 69,33% lived in Natal/RN, 50,00% had completed high school; 58,64% were married; 69,75% had children, 46,91% were between 1 and 4 years of training; 61,73% had improvement courses; 59,25% had 3 to 4 years of service; 54,32%, with 1-4 years experience in emergency; 44,44% received 1-2 minimum wages; 78,40% received insalubrity premium; 67,28% worked in Basic Support Unit (BSU); 83,95% had journey on SAMU Metropolitano of 31-40 hours per week; 52,47% had other employments. As for knowledge of rules of standard precautions, safety and occupational hazards, 99,38% knew what it was WRA; 62,96% gave incomplete answers; 74,07% knew the rules of prevent WRA; 46,67% acquired this knowledge in lectures; 53,09% knew Personal Protective Equipment (PPE); 71,60% gave incorrect answers about the importance of standard precautions; 45,06% never received an educational intervention on this issue; 89,51% said that educational interventions in the prevention of WRA are very important; 90,12% pointed out this as a very important issue in the workplace; 27,00% suggested guidance on the topic in the workplace; regarding the physical hazards, 34,57% considered noise as the most important; about chemical hazards, 78,40% chose the gases and smoke; for biological hazards, 48,77% reported contact with the blood; for mechanical hazards, 80,86% said that were transport accidents; about ergonomic risks, 40,12% say it is the tension/stress in the care of critically ill, psychiatric and aggressive patients; and there was an average of 4,5 to the feeling of safety in the workplace. Regarding the data on the WRAs occurred, 31,48% experienced at least one accident event; 72,55% did not notify it; 60,98% answered that there was no routine for notification; 56,86% were performing patient transportation; 49,02% were hurt in the Basic Support Unit/Rescue Unit (BSU/RH); 60,78% occurred during the day; 96,08% of professionals were in normal work schedule (24 hours on duty); 31,37% had contusion; 58.82% had damage to members/pelvic girdle; 43,14% had traffic accidents. About the evolution of the WRA, 62,75% did not have to take time away from work; 76,47% had no sequelae; 88,24% did not require rehabilitation; no professional had a change of occupation. And by means of univariate logistic regression, showed that the nurses and male sex were risk factors for the occurrence of WRA. We conclude that there were gaps in the knowledge of staff regarding WRA, emphasizing the need for continuing education in biosafety in the service.
Resumo:
The Knowledge Management in organizations is a continuous process of learning that is given by the integration of data, information and the ability of people to use this information. The Management Skills is concerned to understand the powers of officials in the face of organizational skills (teams) and professionals (or tasks positions) want. Joints are located in the greater context of the economy of organizatio s and have the same assumption: that the possession of scarce resources, valuable and difficult to imitate gives the organization a competitive advantage. In this sense, this thesis proposes a model of knowledge management based on analysis of GAP of powers, namely the gap between the skills needed to reach the expected performance and skills already available in the organization, officials and trainees of Coordination of Registration of conductors of DETRAN-RN. Using the method of survey research could make an analysis of academic skills, techniques and emotional individual and a team of officials and trainees, identifying levels of GAP's competence in that sector of the organization and suggest a plan for training , A level of expertise for each sector of coordination, and propose a model for Knowledge Management to help the management of GAP's identified
Resumo:
The bidimensional periodic structures called frequency selective surfaces have been well investigated because of their filtering properties. Similar to the filters that work at the traditional radiofrequency band, such structures can behave as band-stop or pass-band filters, depending on the elements of the array (patch or aperture, respectively) and can be used for a variety of applications, such as: radomes, dichroic reflectors, waveguide filters, artificial magnetic conductors, microwave absorbers etc. To provide high-performance filtering properties at microwave bands, electromagnetic engineers have investigated various types of periodic structures: reconfigurable frequency selective screens, multilayered selective filters, as well as periodic arrays printed on anisotropic dielectric substrates and composed by fractal elements. In general, there is no closed form solution directly from a given desired frequency response to a corresponding device; thus, the analysis of its scattering characteristics requires the application of rigorous full-wave techniques. Besides that, due to the computational complexity of using a full-wave simulator to evaluate the frequency selective surface scattering variables, many electromagnetic engineers still use trial-and-error process until to achieve a given design criterion. As this procedure is very laborious and human dependent, optimization techniques are required to design practical periodic structures with desired filter specifications. Some authors have been employed neural networks and natural optimization algorithms, such as the genetic algorithms and the particle swarm optimization for the frequency selective surface design and optimization. This work has as objective the accomplishment of a rigorous study about the electromagnetic behavior of the periodic structures, enabling the design of efficient devices applied to microwave band. For this, artificial neural networks are used together with natural optimization techniques, allowing the accurate and efficient investigation of various types of frequency selective surfaces, in a simple and fast manner, becoming a powerful tool for the design and optimization of such structures
Resumo:
This work has as main objective the study of arrays of microstrip antennas with superconductor rectangular patch. The phases and the radiation patterns are analyzed. A study of the main theories is presented that explain the microscopic and macroscopic phenomena of superconductivity. The BCS, London equations and the Two Fluid Model, are theories used in the applications of superconductors, at the microstrip antennas and antennas arrays. Phase Arrangements will be analyzed in linear and planar configurations. The arrangement factors of these configurations are obtained, and the phase criteria and the spacing between the elements, are examined in order to minimize losses in the superconductor, compared with normal conductors. The new rectangular patch antenna, consist of a superconducting material, with the critical temperature of 233 K, whose formula is Tl5Ba4Ca2Cu9Oy, is analyzed by the method of the Transverse nTransmission Line (TTL), developed by H. C. C. Fernandes, applied in the Fourier Transform Domain (FTD). The TTL is a full-wave method, which has committed to obtaining the electromagnetic fields in terms of the transverse components of the structure. The inclusion of superconducting patch is made using the complex resistive boundary condition, using the impedance of the superconductor in the Dyadic Green function, in the structure. Results are obtained from the resonance frequency depending on the parameters of the antenna using superconducting material, radiation patterns in E-Plane and H -Plane, the phased antennas array in linear and planar configurations, for different values of phase angles and different spacing between the elements
Resumo:
This Dissertation aims to provide a communication mechanism between Digital TV viewers and interaction devices, such as robots, for example, placed on the environment from which a TV program is being live broadcasted. Such communication mechanism has the objective to allow viewers controll the Interaction Devices through their TV devices, using the broadcast channel present in Interactive Digital TV systems, and receive data from the devices by the broadcast channel. This system was projected as a middlewaer system where the Interaction Devices in the TV program set are interconnected, creating a Interactive Device Network. With this approach, the system is capable of manage the devices on the network, controlling the flow of coming and leaving elements, in a transparent way for the viewers. The system yet allows the Interaction Devices communicate each other, with a integrated communication channel with no worries about the physical communication layer
Resumo:
Frequency Selective Surfaces (FSS) are periodic structures in one or two dimensions that act as spatial filters, can be formed by elements of type conductors patches or apertures, functioning as filters band-stop or band-pass respectively. The interest in the study of FSS has grown through the years, because such structures meet specific requirements as low-cost, reduced dimensions and weighs, beyond the possibility to integrate with other microwave circuits. The most varied applications for such structures have been investigated, as for example, radomes, antennas systems for airplanes, electromagnetic filters for reflective antennas, absorbers structures, etc. Several methods have been used for the analysis of FSS, among them, the Wave Method (WCIP). Are various shapes of elements that can be used in FSS, as for example, fractal type, which presents a relative geometric complexity. This work has as main objective to propose a simplification geometric procedure a fractal FSS, from the analysis of influence of details (gaps) of geometry of the same in behavior of the resonance frequency. Complementarily is shown a simple method to adjust the frequency resonance through analysis of a FSS, which uses a square basic cell, in which are inserted two reentrance and dimensions these reentrance are varied, making it possible to adjust the frequency. For this, the structures are analyzed numerically, using WCIP, and later are characterized experimentally comparing the results obtained. For the two cases is evaluated, the influence of electric and magnetic fields, the latter through the electric current density vector. Is realized a bibliographic study about the theme and are presented suggestions for the continuation of this work
Resumo:
The great diversity in the architecture of biomedical devices, coupled with their different communication protocols, has hindered the implementation of systems that need to make access to these devices. Given these differences, the need arises to provide access to such a transparent manner. In this sense, this paper proposes an embedded architecture, service-oriented, for access to biomedical devices, as a way to abstract the mechanism for writing and reading data on these devices, thereby contributing to the increase in quality and productivity of biomedical systems so as to enable that, the focus of the development team of biomedical software, is almost exclusively directed to its functional requirements