887 resultados para 3.5G EUL Techniques
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Wisdom's method is applied to 5 : 2 and 7 : 3 resonances. Comparisons with Yoshikawa's nontruncated model are performed: for moderate values of eccentricity, agreement is good, especially for the 5 : 2 resonance. A clear difference between the 5 : 2 and the 7 : 3 resonances is observed: the former (like the 3 : 1 resonance) can suffer significant variations of eccentricity, even starting from very small values close to 0, while the latter seems to undergo such variations but the minimum eccentricity cannot be less than a value near 0.1. In the 7 : 3 resonance, some chaotic motion trapped in a region of very small eccentricity is possible. This is in contrast with the 5 : 2 commensurability, since chaos in this case seems to be always related to significant variations of eccentricity. Recent calculations performed by Šidlichovskÿ using mapping techniques show agreement with the results presented here. © 1992.
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Eletronicalceramics are used in many applications such as: multilayer capacitor, transducer, pyroelectric sensors and electrooptic devices. In recent years there has been a growing demand for eletronicalceramics with better performance and functionality. This demand has accelerated the development of synthesis techniques to produce powders with well-defined particle size, shape and crystallinity. The eletronicalceramics in the form of bulk are determined by their performance characteristics of the powders used and the preparation process. So, physical and chemical properties of powders, such as chemical control of stoichiometry, purity, homogeneity, particle size and shape should be observed when choosing the methods of synthesis. Among the techniques used so far, the polymeric precursor method, also known as Pechini, has been considered ideal for the preparation of nanosized powders. Thus, this research project aims to use the polymeric precursor method to prepare powders of lithium tantalate and lanthanum tantalate, with good chemical stability. In this aspect is proposed to investigate the effects of variation of the concentration of europium about the properties of tantalate because doping with Eu3 + indicates that they may occupy different sites in the crystal structure, as in the case of LiTaO3. Effects of things like occupation sites, stability of phases and formation temperature have been previously investigated by the group, which motivated the formulation of this project. Our proposal aims to introduce the Eu3 + LaTaO4 and LiTaO3 and study the structural and optical properties of the powders obtained by Pechini method, as well as correlate these studies with the electrical properties of the material, mainly the Ironelectricty Hysteresis.
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The purpose of this study was to evaluate the impact of different disinfection solutions on flexural resistance of chemically-activated acrylic resin. Test pieces were made of clear acrylic resin using a rectangular mold and employing two techniques: wet polymerization under pressure (n = 20) and dry polymerization under pressure (n = 20). Test pieces were subdivided into four equal groups: distilled water (control), sodium bicarbonate, 1% sodium hypochlorite and effervescent ats. The 30-day cycling technique consisted of immersing the test pieces in 100 ml of solution for 10 min three times a day and placing them in closed containers containing artificial saliva at 37°C. Subsequently, the flexural resistance of samples was tested. Data were analyzed using two-way analysis of variance (ANOVA) with forces serving as the dependent variables and the polymerization technique and cleaning agents as independent variables. Post hoc multiple comparisons were performed using Tukey’s test. There was no statistically significant difference in the flexural strength between the two polymerization techniques. The greatest flexural strength was observed for the effervescent tablets group followed by the control and 1% sodium hypochlorite groups which were statistically similar. Thus, the sodium bicarbonate solution caused the lowest flexural resistance of the test pieces.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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This is a clinical case report of a patient who presented with dental stains in the buccal and proximal aspects of the anterior teeth. Buccal stains were removed using the enamel microabrasion technique, and vital tooth bleaching with carbamide peroxide was also performed. Restorative procedures employing composite resin were done for a better result in the proximal aspect of teeth. Clinical significance: The authors observed the combination of these esthetic techniques improved the patient's smile. Today, dental esthetics attempts to imitate natural teeth by making them white, well-shaped, and aligned with no spots. This has enabled the development of several esthetic techniques, such as microabrasion to remove dental enamel surface stains and surface irregularities,1-6 and vital tooth bleaching to treat yellowish teeth.7 The enamel microabrasion technique uses different abrasive agents associated with chemical solutions,1,2,4,6 allowing the removal of intrinsic, hard-texture stains, and different coloring spots on the enamel surface, as well as correction of irregularities on the dental buccal surface.1,8 The various microabrasive products include the Opalustre® (Ultradent Products, http://www.ultradent.com)or Prema® Compound (Premier Dental Products, http://www.premusa.com), a low-concentration hydrochloric acid product associated with silica microparticles that is certainly effective for microabrasion technique,4,6,9,10 providing a good safety profile for the patient and professional. The microabrasion technique also promotes micro-reduction on the adamantine surface.4,5,10 In some cases, after its completion, microabrasion may cause teeth to become darker or yellowish because of the thinner remaining enamel surface, leading to more evident observation of the dentinal tissue, which in general determines tooth color. In these clinical conditions, correction of the color pattern of dental elements can be obtained with carbamide peroxide products applied in custom trays, such as the bleaching products Whiteness Perfect at 10% or 16% (FGM Productos Odontologicos, http://www.fgm.ind.br) or Opalescence® at 10% or 15% (Ultradent Products), with a considerable margin of clinical success, provided it is well indicated, well performed, and supervised by the professional.4,6,9,10 Considering all the aforementioned aspects, the authors present a clinical case about a dental-enamel microabrasion technique used to remove buccal enamel surface stains associated with dental vital bleaching and restorative procedures in the proximal aspect of anterior teeth. - See more at: https://www.dentalaegis.com/cced/2010/08/different-esthetic-techniques-used-in-combination-to-recover-the-smile#sthash.McFoH7El.dpuf
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Darunavir, a protease inhibitor used in the treatment of HIV infection, presents few methods for its determination in pharmaceuticals. Infrared (IR) spectroscopy offers the possibility of obtaining spectra relatively quickly, providing interesting information, analytically, qualitatively or quantitatively. Capillary electrophoresis (CE) performs separations of high efficiency in shorter time with reagents and samples in small quantity. These two methods are cost-benefitted when we evaluate the green level and the cost of analysis. Faster and cheaper methods without generating organic waste by IR and CE for the quantification of darunavir were developed and validated, focusing socioeconomic impact of analytical decisions. If the cost of acquisition, maintenance, production, analysis and conditioning of drugs and pharmaceuticals is high, consequently the price of this product in the market will be higher and it cannot be accessible to the patient. Treatment failure not only affects the quality of life of patients, but also contributes significantly to the economic burden of the health system. In this context there is a tool called Analysis of the Life Cycle, which comes to make us think in a multidimensional way focusing the whole, the parts and especially the interaction among the parts of a system.
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Pós-graduação em Ciência dos Materiais - FEIS
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The bronze bug, Thaumastocoris peregrinus, is an important pest affecting Eucalyptus plantations. The egg parasitoid Cleruchoides noackae was introduced in Brazil in 2012 for biological control of this pest. A mass rearing of C. noackae was established at EMBRAPA Florestas. This paper summarizes the main techniques developed to date in order to maximize the production of adult C. noackae. The use of eggs laid on towel paper strips increased the number of emerging parasitoids when compared to cutouts of Eucalyptus leaves. Host eggs 2 days old are preferred by C. noackae over 3- or 4-day-old ovipostures. Eggs can be stored at 5 ºC for 30 days after being parasitized without signifi cant effects on parasitoid emergence; such storage is a convenient strategy. The mean parasitoid emergence varies signifi cantly with the density of host eggs; an increase in the number of host eggs offered reduced the number of parasitoids that emerged. These improvements have played a signifi cant role in the production of C. noackae that has made possible mass release of C. noackae in Brazil and the establishment of natural populations of the parasitoid, as recently confi rmed.
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Pós-graduação em Matemática em Rede Nacional - IBILCE
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The reaction of living anionic polymers with 2,2,5,5-tetramethyl-1-(3-bromopropyl)-1-aza-2,5- disilacyclopentane (1) was investigated using coupled thin layer chromatography and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Structures of byproducts as well as the major product were determined. The anionic initiator having a protected primary amine functional group, 2,2,5,5-tetramethyl- 1-(3-lithiopropyl)-1-aza-2,5-disilacyclopentane (2), was synthesized using all-glass high-vacuum techniques, which allows the long-term stability of this initiator to be maintained. The use of 2 in the preparation of well-defined aliphatic primary amine R-end-functionalized polystyrene and poly(methyl methacrylate) was investigated. Primary amino R-end-functionalized poly(methyl methacrylate) can be obtained near-quantitatively by reacting 2 with 1,1-diphenylethylene in tetrahydrofuran at room temperature prior to polymerizing methyl methacrylate at -78 °C. When 2 is used to initiate styrene at room temperature in benzene, an additive such as N,N,N',N'- tetramethylethylenediamine is necessary to activate the polymerization. However, although the resulting polymers have narrow molecular weight distributions and well-controlled molecular weights, our mass spectra data suggest that the yield of primary amine α-end-functionalized polystyrene from these syntheses is very low. The majority of the products are methyl α-end-functionalized polystyrene.
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Observability measures the support of computer systems to accurately capture, analyze, and present (collectively observe) the internal information about the systems. Observability frameworks play important roles for program understanding, troubleshooting, performance diagnosis, and optimizations. However, traditional solutions are either expensive or coarse-grained, consequently compromising their utility in accommodating today’s increasingly complex software systems. New solutions are emerging for VM-based languages due to the full control language VMs have over program executions. Existing such solutions, nonetheless, still lack flexibility, have high overhead, or provide limited context information for developing powerful dynamic analyses. In this thesis, we present a VM-based infrastructure, called marker tracing framework (MTF), to address the deficiencies in the existing solutions for providing better observability for VM-based languages. MTF serves as a solid foundation for implementing fine-grained low-overhead program instrumentation. Specifically, MTF allows analysis clients to: 1) define custom events with rich semantics ; 2) specify precisely the program locations where the events should trigger; and 3) adaptively enable/disable the instrumentation at runtime. In addition, MTF-based analysis clients are more powerful by having access to all information available to the VM. To demonstrate the utility and effectiveness of MTF, we present two analysis clients: 1) dynamic typestate analysis with adaptive online program analysis (AOPA); and 2) selective probabilistic calling context analysis (SPCC). In addition, we evaluate the runtime performance of MTF and the typestate client with the DaCapo benchmarks. The results show that: 1) MTF has acceptable runtime overhead when tracing moderate numbers of marker events; and 2) AOPA is highly effective in reducing the event frequency for the dynamic typestate analysis; and 3) language VMs can be exploited to offer greater observability.
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Considering the ecological importance of stingless bees as caretakers and pollinators of a variety of native plants makes it necessary to improve techniques which increase of colonies' number in order to preserve these species and the biodiversity associated with them. Thus, our aim was to develop a methodology of in vitro production of stingless bee queens by offering a large quantity of food to the larvae. Our methodology consisted of determining the amount of larval food needed for the development of the queens, collecting and storing the larval food, and feeding the food to the larvae in acrylic plates. We found that the total average amount of larval food in a worker bee cell of E varia is approximately 26.70 +/- 3.55 mu L. We observed that after the consumption of extra amounts of food (25, 30, 35 and 40 mu L) the larvae differentiate into queens (n = 98). Therefore, the average total volume of food needed for the differentiation of a young larva of F. varia queen is approximately 61.70 +/- 5.00 mu L. In other words; the larvae destined to become queens eat 2.31 times more food than the ones destined to become workers. We used the species Frieseomelitta varia as a model, however the methodology can be reproduced for all species of stingless bees whose mechanism of caste differentiation depends on the amount of food ingested by the larvae. Our results demonstrate the effectiveness of the in vitro technique developed herein, pointing to the possibility of its use as a tool to assist the production of queens on a large scale. This would allow for the artificial splitting of colonies and contribute to conservation efforts in native bees.
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Among the osteotomies performed in orthognathic surgery, the sagittal osteotomy of the mandibular ramus (SOMR) is the most common, allowing a great range of movements and stable internal fixation (SIF), therefore eliminating the need of maxillomandibular block in the postoperative period. Objectives: The purpose of this study was to evaluate the biomechanical resistance of three national systems used for SIF in SOMR in sheep mandibles. Material and methods: The study was performed in 30 sheep hemi-mandibles randomly divided into 3 experimental groups, each containing 10 hemi-mandibles. The samples were measured to avoid discrepancies and then subjected to SOMR with 5-mm advancement. In group I, 2.0x12 mm screws were used for fixation, inserted in an inverted "L" pattern (inverted "L" group). In group II, fixation was performed with two 2.0x12 mm screws, positioned in a linear pattern and a 4-hole straight miniplate and four 2.0x6.0 mm monocortical screws (hybrid group). In group III, fixation was performed with two-hole straight miniplates and eight 2.0x6.0 mm monocortical screws (mini plate group). All materials used for SIF were supplied by Osteosin - SIN. The hemimandibles were subjected to vertical linear load test by Kratos K2000MP mechanical testing unit for loading registration and displacement. Results: All groups showed similar resistance during mechanical test for loading and displacement, with no statistically significant differences between groups according to analysis of variance. Conclusion: These results indicate that the three techniques of fixation are equally effective for clinical fixation of SOMR.
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As a part of the AMAZE-08 campaign during the wet season in the rainforest of central Amazonia, an ultraviolet aerodynamic particle sizer (UV-APS) was operated for continuous measurements of fluorescent biological aerosol particles (FBAP). In the coarse particle size range (> 1 mu m) the campaign median and quartiles of FBAP number and mass concentration were 7.3x10(4) m(-3) (4.0-13.2x10(4) m(-3)) and 0.72 mu g m(-3) (0.42-1.19 mu g m(-3)), respectively, accounting for 24% (11-41%) of total particle number and 47% (25-65%) of total particle mass. During the five-week campaign in February-March 2008 the concentration of coarse-mode Saharan dust particles was highly variable. In contrast, FBAP concentrations remained fairly constant over the course of weeks and had a consistent daily pattern, peaking several hours before sunrise, suggesting observed FBAP was dominated by nocturnal spore emission. This conclusion was supported by the consistent FBAP number size distribution peaking at 2.3 mu m, also attributed to fungal spores and mixed biological particles by scanning electron microscopy (SEM), light microscopy and biochemical staining. A second primary biological aerosol particle (PBAP) mode between 0.5 and 1.0 mu m was also observed by SEM, but exhibited little fluorescence and no true fungal staining. This mode may have consisted of single bacterial cells, brochosomes, various fragments of biological material, and small Chromalveolata (Chromista) spores. Particles liquid-coated with mixed organic-inorganic material constituted a large fraction of observations, and these coatings contained salts likely from primary biological origin. We provide key support for the suggestion that real-time laser-induce fluorescence (LIF) techniques using 355 nm excitation provide size-resolved concentrations of FBAP as a lower limit for the atmospheric abundance of biological particles in a pristine environment. We also show some limitations of using the instrument for ambient monitoring of weakly fluorescent particles < 2 mu m. Our measurements confirm that primary biological particles, fungal spores in particular, are an important fraction of supermicron aerosol in the Amazon and that may contribute significantly to hydrological cycling, especially when coated by mixed inorganic material.