Avaliação dos modelos de predição de propagação para telefonia móvel celular na cidade do Natal

The development of wireless telecommunication in the last years has been great. It has been taking academics to conceive new ideas and techniques. Their aims are to increase the capacity and the quality of the system s services. Cells that are smaller every time, frequencies that are every time higher and environments that get more and more complex, all those facts deserve more accurate models the propagation prediction techniques are inserted in this context and results with a merger of error that is compatible with the next generations of communication systems. The objective of this Work is to present results of a propagation measurement campaign, aiming at pointing the characteristics of the mobile systems covering in the city of Natal (state of Rio Grande do Norte, Brazil). A mobile laboratory was set up, using the infra-structure available and frequently used by ANATEL. The measures were taken in three different areas: one characterized by high buildings, high relief, presence of trees and towers of different highs. These areas covered the city s central zone, a suburban / rural zone and a section of coast surrounded by sand dunes. It is important to highlight that the analysis was made taking into consideration the actual reality of cellular systems with covering ranges by reduced cells, with the intent of causing greater re-use of frequencies and greater capacity of telephone traffic. The predominance of telephone traffic by cell in the city of Natal occurs within a range inferior to 3 (three) km from the Radio-Base Station. The frequency band used was 800 MHz, corresponding to the control channels of the respective sites, which adopt the FSK modulation technique. This Dissertation starts by presenting a general vision of the models used for predicting propagation. Then, there is a description of the methodology used in the measuring, which were done using the same channels of control of the cellular system. The results obtained were compared with many existing prediction models, and some adaptations were developed by using regression techniques trying to obtain the most optimized solutions. Furthermore, according to regulations from the old Brazilian Holding Telebrás, a minimum covering of 90% of a determined previously area, in 90% of the time, must be obeyed when implanting cellular systems. For such value to be reached, considerations and studies involving the specific environment that is being covered are important. The objective of this work is contribute to this aspect

Análise do desempenho térmico de sistema constutivo de concreto com EPS como agregado graúdo

In the last decades there was a concentrate effort of researchers in the search for options to the problem of the continuity of city development and environmental preservation. The recycling and reuse of materials in industry have been considerate as the best option to sustainable development. One of the relevant aspects in this case refers to the rational use of electrical energy. At this point, the role of engineering is to conceive new processes and materials, with the objective of reducing energy consumption and maintaining, at the same time the benefits of the technology. In this context, the objective of the present research is to analyze quantitatively the thermal behavior of walls constructed with concrete blocks which composition aggregates the expanded polystyrene (EPS) reused in the shape of flakes and in the shape of a board, resulting in a “light concrete”. Experiments were conducted, systematically, with a wall (considerate as a standard) constructed with blocks of ordinary concrete; two walls constructed with blocks of light concrete, distinct by the proportion of EPS/sand; a wall of ceramic bricks (“eight holes” type) and a wall with ordinary blocks of cement, in a way to obtain a comparative analysis of the thermal behavior of the systems. Others tests conducted with the blocks were: stress analysis and thermal properties analysis (ρ, cp e k). Based on the results, it was possible to establish quantitative relationship between the concentration (density) of EPS in the constructive elements and the decreasing of the heat transfer rate, that also changes the others thermal properties of the material, as was proved. It was observed that the walls of light concrete presents better thermal behavior compared with the other two constructive systems world wide used. Based in the results of the investigation, there was shown the viability of the use of EPS as aggregate (raw material) in the composition of the concrete, with the objective of the fabrication of blocks to non-structural masonry that works as a thermal insulation in buildings. A direct consequence of this result is the possibility of reduction of the consume of the electrical energy used to climatization of buildings. Other aspect of the investigation that must be pointed was the reuse of the EPS as a raw material to civil construction, with a clear benefit to reducing of environmental problems

Compósito Polimérico Híbrido: Comportamento Mecãnico, Descotinuidade Geométrica e Resistência Residual

The growing demand in the use of hybrid composite materials makes it essential a better understanding of their behavior face of various design conditions, such as the presence of geometric discontinuities in the cross section of structural elements. This way, the purpose of this dissertation is a study of the mechanical response (strength and stiffness), modes (characteristics) of fracture and Residual Strength of an hybrid polymeric composite with and without a geometric discontinuity in its longitudinal section (with a reduction in the cross section) loaded by uniaxial tension. This geometric discontinuity is characterized by central holes of different diameters. The hybrid composite was fabricated as laminate (plate) and consisting of ortho-tereftalic polyester matrix reinforced by 04 outer layers of Jute fibers bidirectional fabrics and 01 central layer of E-glass bidirectional fabric. The laminate was industrially manufactured (Tecniplas Nordeste Indústria e Comércio Ltda.), obtained by the hand lay-up technique. Initially, a study of the volumetric density of the laminate was made in order to verify its use in lightweight structures. Also were performed comparative studies on the mechanical properties and fracture modes under the conditions of the specimens without the central hole and with the different holes. For evaluating the possible influence of the holes in the structural stability of the laminate, the Residual Strength of the composite was determined for each case of variation in hole diameter. As a complementary study, analyses of the macroscopic final fracture characteristic of the laminates were developed. The presence of the central hole of any sizes, negatively changed the ultimate tensile strength. Regarding the elastic modulus, moreover, the difference found between the specimens was within the range of tests displacement, showing the laminate stability related to the stiffness

Influência da formação de pozolanas com adição de metacaulim em concreto de alta resistência

The need to build durable structures and resistant to harsh environments enabled the development of high strength concrete, these activities generate a high cement consumption, which implies factor in CO2 emissions. Often the desired strength is not achieved using only the cement composition. This study aims to evaluate the influence of pozzolans with the addition of metakaolin on the physical mechanics of high strength concrete comparing them with the standard formulation. Assays were performed to characterize the aggregates according to NBR 7211, evaluation of cement and coarse aggregate through the trials of petrography (NBR 15577-3/08) and alkali-aggregate reaction (NBR 15577-05/08). Specimens were fabricated according to NBR 5738-1/04 with additions of 0%, 4%, 6%, 8% and 10% of metakaolin for cement mortars CP V in the formulations. For evaluation of the concrete hardened in fresh state and scattering assays were performed and compressive strength in accordance with the NBR 7223/1992 and NBR 5739-8/94 respectively. The results of the characterization of aggregates showed good characteristics regarding size analysis and petrography, as well as potentially innocuous as the alkali-aggregate reaction. As to the test of resistance to compression, all the formulations with the addition of metakaolin showed higher value at 28 days of disruption compared with the standard formulation. These results present an alternative to reduce CO2 emissions, and improvements in the quality and durability of concrete, because the fine particle size of metakaolin provides an optimal compression of the mass directly influencing the strength and rheology of the dough

Estudo da incorporação de resíduo industrial polimérico ao CAP

This work presents the incorporation of an industrial polymeric waste into a petroleum asphalt cement with penetration grade 50-60 (CAP 50-60). The main goal of this research is the development of a polymer-modified asphalt, with improvements in its physical properties, in order to obtain a more resistant material to the traffic loads. Furthermore, the use of this polymeric waste will result in economic and environmental benefits. The CAP 50-60 used in this research was kindly supplied by LUBNOR Lubrificantes e Derivados de Petróleo do Nordeste (produced in Fazenda Belém Aracati - Ceará) and the industrial polymeric waste was provided by a button manufacturer industry, located in Rio Grande do Norte state. This polymeric waste represents an environmental problem due to its difficulty in recycling and disposal, being necessary the payment by the industry to a landfill. The difficulty in its reuse is for being this material a termofixed polymer, as a result, the button chips resulting from the molding process cannot be employed for the same purpose. The first step in this research was the characterization of the polymeric waste, using Differential Scanning Calorimetry (DSC) Infrared spectroscopy (IR spectroscopy), and Thermogravimetric analysis (TGA). Based on the results, the material was classified as unsaturated polyester. After, laboratory experiments were accomplished seeking to incorporate the polymeric waste into the asphalt binder according to a 23 experimental factorial design, using as main factors: the polymer content (2%, 7% and 14%), the temperature of the mixture (140 and 180 oC) and the reaction time (20 and 60 minutes). The characterization of the polymer-modified asphalt was accomplished by traditional tests, such as: penetration, ring and ball softening point, viscosity, ductility and flash point temperature. The obtained results demonstrated that the addition of the polymeric waste into the asphalt binder modified some of its physical properties. However, this addition can be considered as a feasible alternative for the use of the polymeric waste, which is a serious environmental and technological problem.

Incorporação do resíduo oriundo do beneficiamento de caulim em concreto asfáltico

The municipal district of Equador-RN is located in an area of great amounts of ores, being your main economical activity the extraction and the kaolin improvement. The main originating from environmental problem that activity is the amount of generated residue, about 70% of the extracted kaolin. The residues are simply piled up in lands of the improvement companies, occupying like this a large area and causing impact in the existent flora. When dry, the residues transform powdered and for the action of the wind, they disperse, polluting the air. Being like this, the present work has as objective evaluates the incorporation of the great residue, originating from of the kaolin improvement, in partial substitution of all the employed aggregates in a conventional mixture of asphalt concrete, which was used in the paving of BR101/RN061 - passage between Ponta Negra and Ares. That evaluation was accomplished in three stages. The first refers to the evaluation of the physical, thermal and mineralogical characteristics of the residue with the intention of to classify it and to define your application as aggregate (small and great). The second refers to the physical characterization of the aggregates and of the asphalt material used in the conventional mixture. And the third, to the evaluation of the mixtures containing residue, which were elaborated starting from the conventional mixture with the gradual incorporation of the residue, from 5 to 40%, in substitution to the part of the conventional aggregates, in way to obtain similar particle size curves the one of the conventional mixture. That evaluation was accomplished through the comparison between the volumetric composition, the mechanical behavior and the susceptibility to the humidity of the mixtures containing residue with the one of the conventional mixture, and with the one of the DNIT specifications. The results show that the great residue originating from of the kaolin improvement has grains of the most varied size, being like this, it can substitute part of all the conventional aggregates and of the filler in an asphalt mixture. Besides, your mineralogical composition presented the same present minerals in the composition of conventional aggregates used in paving. The results evaluation of the volumetric composition of the mixtures containing residue indicates that it can use up to 30% of residue in substitution to the conventional aggregates. The evaluation of the mechanical behavior of those mixtures indicates that the residue increment in the studied mixtures caused an increase of the stability and a reduction of the resistance to the traction. The values obtained in the resistance to the traction meet below the minimum value specified by DNIT, but close to the value obtained in the conventional mixture. When taking in consideration the susceptibility of the same ones to the humidity, the results indicate that she can use up to 25% of residue

Análise experimental de blocos intertravados de concreto com adição de resíduos do processo de recauchutagem de pneus

Analysis of experimental interlocking blocks of concrete with addition of residues of process the tires retreading production. With the population growth in recent years, industry in general has adjusted itself to resulting demand. the industry of tire retreading generates residues that have been discarded without any control. this adds to environmental pollution and promotes the proliferation of vectors harmful to health, aiming to find an application for this type of residues, this study presents experimental results to interlocking concrete block pavements, with addition of residues tires, interlocking blocks were built up and we determined, through laboratory tests, the need to set the mark that provide greater return regarding analyzed characteristics, there are four types of dosage of concrete with residues tires. We accomplished tests of compression strength, water absorption and resistance to impact. Through the preliminary results, we verified that are satisfactory, confirming the possibility of applying this type of interlocking block in environments with low demand, which would bring the economy of natural sources of aggregates, beyond ecological benefits through the reuse of residues from retreading of tires.

Resposta celular Th1 /Th2 na doença periodontal experimental, em ratos: um estudo imuno-histoquímico

Host response plays a major role in the pathogenesis of periodontal disease. Mediators such as inflammatory cytokines which are secreted during the immune response to bacterial challenges have ambiguous functions that may or may not lead to protection of the attacked tissue. In this context, experimental evidence suggests that T-helper 1 (Th-1) and T-helper 2 (Th-2) mediated responses are potentially important during the disease process. The aims of this study therefore were to further clarify the role played by Th2 cells during different time points of the active phase of periodontal disease, as well as, to investigate whether there was any evidence of a Th1 response in the periodontal disease microenvironment. Experimental periodontitis was induced in 30 Wistar male rats by placing cotton ligatures around the mandibular first molars. The rats were then randomly divided into two groups. Group1 (G1=15) and Group 2 (G2=15). In G1 the ligatures were maintained for 2 days, whereas in G2 the ligatures were left for 15 days, a time point that corresponds to the advanced stage of periodontal disease The contra-lateral teeth served as controls (no ligatures). Immunohistochemical investigation for the presence in gingival tissue of Th2 specific transcription factor (GATA3) and the subunit of the IFN-γ receptor was carried out after the disease induction period. Light microscopy analysis revealed a decrease in the expression of GATA-3 as bone loss progressed. On the other hand, although IFN-γ R1 was detected at an early stage of the active phase of disease its expression remained unaltered during the remaining period of the study. These results indicate that the Th2 response have a protective role during the pathogenesis of periodontal disease and that the progression of the periodontal disease is related with the unbalance of the responses Th1/Th2

Estudo da detecção do DNA do papiloma vírus humano (HPV) e da expressão imuno-histoquímica de proteína do ciclo celular no carcinoma epidermóide oral

Oral squamous cell carcinoma (OSCC) is the most common malignancy in oral cavity and human papillomavirus (HPV) may have an important role in its development. The aim of this experiment was to investigate the HPV DNA and viral types in 90 cases of OSCC. Moreover, a comparative analysis between the cases of OSSC with and without HPV DNA was performed by using cell cycle markers p21 and pRb in order to detect a possible correlation of these proteins and HPV infection. DNA was extracted from paraffin embedded tissue and amplified by PCR (polymerase chain reaction) with primers PCO3+ e PCO4+ for a fragment of human β-globin gene. After this procedure, PCR for HPV DNA detection was realized using a pair of generic primers GP5+ e GP6+. Immunohistochemical study was performed by streptoavidin-biotin technique and antibodies against p21 and pRb proteins were employed. Eighty-eight cases were positive for human β-globin gene and HPV DNA was found in 26 (29.5%) of then. It could not be detected significant correlation between HPV and age, sex and anatomical sites of the lesion. The most prevalent viral type was HPV 18 (80.8%). Regarding the immunohistochemical analysis, it was detected significant association between HPV presence and pRb immunoexpression (p=0,044), nevertheless, the same was not observed in relation to p21 protein (p =0,416). It can be concluded that the low detection of HPV DNA in OSCC by the present experiment suggests a possible role of the virus in the development and progression in just a subset of this disease

Caracaterização do núcleo pré-geniculado do sagüi (Callithrix jacchus) :projeção retiniana, neuroquímica e atividade celular (expressão de FOS)

In rodents, the suprachiasmatic nucleus (SCN) and the intergeniculate leaflet (IGL) are the main components of the circadian system. The SCN is considerate the site of an endogenous biological clock because can to generate rhythm and to synchronize to the environmental cues (zeitgebers) and IGL has been related as one of the main areas that modulate the action of SCN. Both receive projections of ganglion cells of retina and this projection to SCN is called retinohypothalamic tract (RHT). Moreover, the IGL is connected with SCN through of geniculohypothalamic tract (GHT). In primates (include humans) was not still demonstrated the presence of a homologous structure to the IGL. It is believed that the pregeniculate nucleus (PGN) can be the answer, but nothing it was still proven. Trying to answer that question, the objective of our study is to do a comparative analysis among PGN and IGL through of techniques immunohystochemicals, neural tracers and FOS expression after dark pulses. For this, we used as experimental model a primate of the new world, the common marmoset (Callithrix jacchus). Ours results may contribute to the elucidation of this lacuna in the circadian system once that the IGL is responsible for the transmission of nonphotic information to SCN and participate in the integration between photic and nonphotic stimulus to adjust the function of the SCN. In this way to find a same structure in primates represent an important achieve in the understanding of the biological rhythms in those animals

Desenvolvimento de sistema magnético polimérico contendo antimicrobianos para tratamento de infecções por Helicobacter pylori

Helicobacter pylori is the main cause of gastritis, gastroduodenal ulcer disease and gastric cancer. The most recommended treatment for eradication of this bacteria often leads to side effects and patient poor compliance, which induce treatment failure. Magnetic drug targeting is a very efficient method that overcomes these drawbacks through association of the drug with a magnetic compound. Such approach may allow such systems to be placed slowed down to a specific target area by an external magnetic field. This work reports a study of the synthesis and characterization of polymeric magnetic particles loaded with the currently used antimicrobial agents for the treatment of Helicobacter pylori infections, aiming the production of magnetic drug delivery system by oral route. Optical microscopy, scanning electron microscopy, transmission electron microscopy, x-ray powder diffraction, nitrogen adsorption/desorption isotherms and vibrating sample magnetometry revealed that the magnetite particles, produced by the co-precipitation method, consisted of a large number of aggregated nanometer-size crystallites (about 6 nm), creating superparamagnetic micrometer with high magnetic susceptibility particles with an average diameter of 6.8 ± 0.2 μm. Also, the polymeric magnetic particles produced by spray drying had a core-shell structure based on magnetite microparticles, amoxicillin and clarithromycin and coated with Eudragit® S100. The system presented an average diameter of 14.2 ± 0.2 μm. The amount of magnetite present in the system may be tailored by suitably controlling the suspension used to feed the spray dryer. In the present work it was 2.9% (w/w). The magnetic system produced may prove to be very promising for eradication of Helicobacter pylori infections

Relação da expressão de fatores de crescimento celular (IGF-1) e (SCF) com fatores prognósticos e o alvo da rapamicina em mamíferos (m-TOR) em mastocitomas cutâneos caninos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Digestibilidade aparente de rações contendo levedura íntegra, levedura autolisada e parede celular pela tilápia do Nilo

Apparent digestibility coefficient of dry matter, crude protein, ether extract, gross energy, of diets supplemented with spray dried whole yeast (1.0; 2.0 e 3.0%), autolyzed (1.0; 2.0 e 3.0%), yeast cell wall (0.1; 0.2 e 0.3%) plus a additional diet with no yeast and yeast derivatives were evaluated to Nile tilapia. Eighty juveniles (83.0+/-8.5g) were placed in eight 250L aquaria for feeding and four aquaria of the same volume for collecting faecal samples. Both sets were equipped with flow-trough recirculation system provided with mechanical and biological filter. Diets supplemented with whole yeast, autolyzed yeast, and yeast cell wall presented, as mean, superior apparent coefficient digestibility than control. It can be concluded that supplementation of yeast and yeast derivatives improve apparent coefficient digestibility of experimental diets and diets supplemented with estimated level of 2.13-2.36% autolyzed yeast shows better digestibility.

Gel de plaquetas: arcabouço 3D para cultura celular

INTRODUÇÃO: O reparo tissular é o objetivo final da cirurgia. A cultura celular requer arcabouço mecânico que dê suporte ao crescimento celular e difusão dos nutrientes. O uso do plasma rico em plaquetas (PRP) como um arcabouço 3D possui diversas vantagens: é material biológico, de fácil absorção pós-transplante, rico em fatores de crescimento, em especial PDGF- ββ e TGF-β que estimula síntese de matriz extracelular na cartilagem. OBJETIVO: Desenvolver arcabouço 3D à base de PRP. MATERIAIS E MÉTODOS: Duas formas foram idealizadas: Sphere e Carpet. Condições estéreis foram utilizadas. O gel de plaquetas permaneceu em cultura celular, observado diariamente em microscópio invertido. RESULTADOS: Ambos arcabouços obtiveram sucesso, com aspectos positivos e negativos. DISCUSSÃO: A forma Sphere não aderiu ao plástico. Observou-se retração do gel e investigação ao microscópio dificultada devido às áreas opacas no campo visual. A forma Carpet não aderiu ao plástico e apresentou-se translúcida. O tempo de estudo foi de 20 dias. CONCLUSÕES: A produção de um arcabouço 3D PRP foi um sucesso, e trata-se de uma alternativa que necessita ser mais utilizado e investigado para que se consolide em uma rota eficiente e confiável na tecnologia de engenharia tissular, particularmente em cultura de tecido cartilaginoso.

Estudo da oxidação dos sulfetos sintéticos molibdenita (MoS2) e covelita (CuS) por Acidithiobacillus ferrooxidans via respirometria celular

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)