Estudo da previsão da carga de ruptura de estacas pré-moldadas de concreto

The piles are one of the most important types of solution adopted for the foundation of buildings. They are responsible for transmitting to the soil in deepe r and resistant layers loads from structures. The interaction of the foundation element with the soil is a very important variable, making indispensable your domain in order to determine the strength of the assembly and establish design criteria for each c ase of application of the pile. In this research analyzes were performed f rom experiments load tests for precast concrete piles and inve stigations of soil of type SPT, a study was performed for obtaining the ultimate load capacity of the foundation through methods extrapolation of load - settlement curve , semi - empirical and theoretic . After that, were realized comparisons between the different methods used for two types of soil a granular behavior and other cohesive. For obtaining soil paramet ers to be used i n the methods were established empirical correlations with the standard penetration number (NSPT). The charge - settlement curves of the piles are also analyzed. In the face of established comparisons was indicated the most reliable semiempirical method Déco urt - Quaresma as the most reliable for estimating the tensile strength for granular and cohesive soils. Meanwhile, among the methods studied extrapolation is recommended method of Van der Veen as the most appropriate for predicting the tensile strength.

Nursing Activities Score: avaliação da carga de trabalho de enfermagem em unidade de terapia intensiva adulto

The sizing of nursing human resources is an essential management tool to meet the needs of the patients and the institution. Regarding to the Intensive Care Unit, where the most critical patients are treated and the most advanced life-support equipments are used, requiring a high number of skilled workers, the use of specific indicators to measure the workload of the team becomes necessary. The Nursing Activities Score is a validated instrument for measuring nursing workload in the Intensive Care Unit that has demonstrated effectiveness. It is a cross-sectional study with the primary objective of assessing the workload of nursing staff in an adult Intensive Care Unit through the application of the Nursing Activities Score. The study was conducted in a private hospital specialized in the treatment of patients with cancer, which is located in the city of Natal (Rio Grande do Norte – Brazil). The study was approved by the Research Ethics Committee of the hospital (Protocol number 558.799; CAAE 24966013.7.0000.5293). For data collection, a form of sociodemographic characteristics of the patients was used; the Nursing Activities Score was used to identify the workload of nursing staff; and the instrument of Perroca, which classifies patients and provides data related to the their need for nursing care, was also used. The collected data were analyzed using a statistical package. The categorical variables were described by absolute and relative frequency, while the number by median and interquartile range. Considering the inferential approach, the Spearman test, the Wald chi-square, Kruskal Wallis and Mann-Whitney test were used. The statistically significant variables were those with p values <0.05. The evaluation of the overall averages of NAS, considering the first 15 days of hospitalization, was performed by the analysis of Generalized Estimating Equations (GEE), with adjust for the variable length of hospitalization. The sample consisted of 40 patients, in the period of June to August 2014. The results showed a mean age of 62,1 years (±23,4) with a female predominance (57,5%). The most frequent type of treatment was clinical (60,0%), observing an average stay of 6,9 days (±6,5). Considering the origin, most patients (35%) came from the Surgical Center. There was a mortality rate of 27,5%. 277 measures of NAS score and Perroca were performed, and the averages of 69,8% (±24,1) and 22,7% (±4.2) were obtained, respectively. There was an association between clinical outcome and value of the Nursing Activities Score in 24 hours (p <0.001), and between the degree of dependency of patients and nursing workload (rp 0,653, p<0,001). The achieved workload of the nursing staff, in the analyzed period, was presented high, showing that hospitalized patients required a high demand for care. These findings create subsidies for sizing of staff and allocation of human resources in the sector, in order to achieve greater safety and patient satisfaction as a result of intensive care, as well as an environment conducive to quality of life for the professionals

Capacidade de carga de misturas de solo laterítico e desbastes de pneus

Government efforts have found some obstacles in achieving a better infrastructure regarding environmental preservation requirements. There is a need to develop new techniques that leave the big exploitation of environmental resources. This study measures the evaluation of the behavior of a composite formed by lateritic soil mix and tire buffings. In this way, a road embankment model was developed to assess the bearing capacity of the composite. This study measured the load capacity of the composites with 0%, 10%, 20% and 40% rubber mixed with the soil, by weight, iron plate loading tests on a simulated embankment in a metal box of 1.40 x 1.40 x 0.80 m. After four compaction layers of the composite, a plate test was performed, and then stress-settlement curves were obtained for the material. The embankments with 20% and 40% rubber content was difficult to compact. There was a significant reduction in the load capacity of the soil-plate system with increasing rubber content. The composite with the lowest loss of bearing capacity in relation to the reference soil was the one with a χ = 10%. In the load capacity tests, another aspect noted was the bearing capacity in terms of CBR. The results also show a gradual decrease in bearing capacity in the composites as with the rubber incorporation content increases. As in the plate load tests, the composite that had the lower bearing capacity loss was also that with 10% content.

Classificação de técnicas e auxílio à navegação de busca com base em sua carga cognitiva, precisão e eficiência

Navigation, in both virtual and real environments, is the process of a deliberated movement to a specific place that is usually away from the origin point, and that cannot be perceived from it. Navigation aid techniques (TANs) have as their main objective help finding a path through a virtual environment to a desired location and, are widely used because they ease the navigation on these unknown environments. Tools like maps, GPS (Global Positioning System) or even oral instructions are real world examples of TAN usage. Most of the works which propose new TANs for virtual environments aim to analyze their impact in efficiency gain on navigation tasks from a known place to an unknown place. However, such papers tend to ignore the effect caused by a TAN usage over the route knowledge acquisition process, which is important on virtual to real training transfer, for example. Based on a user study, it was possible to confirm that TANs with different strategies affects the performance of search tasks differently and that the efficiency of the help provided by a TAN is not inversely related to the cognitive load of the technique’s aids. A technique classification formula was created. This formula utilizes three factors instead of only efficiency. The experiment’s data were applied to the formula and we obtained a better refinement of help level provided by TANs.

Desenvolvimento de um painel sanduíche com carga de particulado oriundo de resíduo lignocelulósico para aplicação em produtos na área de equipamentos de proteção

This work aims to study and investigate the use of a hybrid composite polymer formed with blanket aramid (Kevlar 29) fiber blanket flax fiber and particulate dry endocarp of coconut (Cocos nucifera Linn), using as matrix an epoxy resin based thermoset for use in areas of protective equipment. Besides such material is used an aluminum plate, joined to the composite by means of glue based on epoxy and araldite commercial. The manufacturing process adopted was manual lamination (Hand Lay Up) to manufacture the hybrid composite. After the composite is prepared, an aluminum plate is subjected to pressure and glued to cure the adhesive. Layers of veil will also be used to separate the particulate from the linen blanket layer without disturbing the alignment of the fibers of the blankets. To characterize the mechanical and physical behavior was manufactured a plate of 800 x 600 mm of the hybrid composite, which were removed specimens for tests of water absorption to saturation; density; impact test (Charpy) and two test specimens for ballistic testing 220 mm x 200 mm to make a comparative study between the dry state and saturated water absorption and thus see the ballistic performance of these two conditions. The test was applied to make a comparative study of fracture in these two conditions, caused by penetrating ballistic missile (38 and 380). To test the impact (Charpy) will analyze the absorbed energy, fracture appearance and lateral contraction, also in dry condition and saturation of absorbed water, thereby analyzing situations where the impact load is relevant, such as bumps and shocks produced by stone, metal or wooden bars among others. The proposed configuration, along with the tests, has the purpose, application in the fields of equipment against ballistic impact, such as helmets; bullet proof vests; shields; protective packaging and other items to be identified in this research.

Obtenção e caracterização de um compósito polimérico de matriz poliéster e reforço/carga de tecido plano de algodão

He was obtained and studied the feasibility of using TPA (Tissue Cotton Plan) screen type, for bagging, with a weight of 207.9 g / m2 in a composite of orthophthalic crystal polyester resin matrix. The process for obtaining the composite was tested against the maximum number of layers that could be used without compromising the processability and manufacturing of CPs in compression mold. Five configurations / formulations were selected and tested at 1, 4, 8, 10 and 12 layers of cotton tissue - TPA. TPA was not subjected to chemical treatment, only by passing a mechanical washing process. The composite in its various configurations / formulations was characterized to determine its physical properties. The properties of the composite were higher viability resistance to bending, approaching the matrix and impact resistance, superiority in relation to the polyester resin. Another property that has shown good result compared to other composite has water absorption. Analyzing all the properties set the settings / formulations with higher viability were TA8 and TA10, by combining good processability and higher mechanical strength, with lower loss compared to polyester resin matrix. The composite showed lower mechanical behavior of the resin matrix for all the formulations studied except the impact resistance. The SEM showed a good adhesion between the layers of TPA and polyester resin matrix, without the presence of micro voids in the matrix confirming the efficient manufacturing process of the samples for characterization. The composite proposed proved to be viable for the fabrication of structures with low requests from mechanical stresses, and as demonstrated for the manufacture of solar and wind prototypes, and packaging, shelving, decorative items, crafts and shelves, with good visual appearance.

Obtenção e caracterização de um compósito polimérico de matriz poliéster e reforço/carga de tecido plano de algodão

He was obtained and studied the feasibility of using TPA (Tissue Cotton Plan) screen type, for bagging, with a weight of 207.9 g / m2 in a composite of orthophthalic crystal polyester resin matrix. The process for obtaining the composite was tested against the maximum number of layers that could be used without compromising the processability and manufacturing of CPs in compression mold. Five configurations / formulations were selected and tested at 1, 4, 8, 10 and 12 layers of cotton tissue - TPA. TPA was not subjected to chemical treatment, only by passing a mechanical washing process. The composite in its various configurations / formulations was characterized to determine its physical properties. The properties of the composite were higher viability resistance to bending, approaching the matrix and impact resistance, superiority in relation to the polyester resin. Another property that has shown good result compared to other composite has water absorption. Analyzing all the properties set the settings / formulations with higher viability were TA8 and TA10, by combining good processability and higher mechanical strength, with lower loss compared to polyester resin matrix. The composite showed lower mechanical behavior of the resin matrix for all the formulations studied except the impact resistance. The SEM showed a good adhesion between the layers of TPA and polyester resin matrix, without the presence of micro voids in the matrix confirming the efficient manufacturing process of the samples for characterization. The composite proposed proved to be viable for the fabrication of structures with low requests from mechanical stresses, and as demonstrated for the manufacture of solar and wind prototypes, and packaging, shelving, decorative items, crafts and shelves, with good visual appearance.

Obtenção e caracterização de um compósito de matriz polimérica com carga de resíduos vegetal proveniente do sabugo de milho

The feasibility of using the corn cob to obtain a polymer matrix composite was studied. To obtain the bran, corncob passed the drying process in a solar dryer, and was subsequently triturated in forage and to obtain the different particle sizes, by sieving. Three different grain sizes were used: fine particles (FP) size between 0,10 and 2mm; sized particles (PM) with sizes between 2,10 and 3,35 mm; large particles (PG) sizes between 3,45 and 4,10 mm. Using 20% of residue relative to the resin, the test samples were constructed for characterization of the composite, taking into account thermal and mechanical parameters. The main advantage of the proposed composite is that it has a low density, below the relative resin, about 1.06 kg / m³ for the PG. The composite showed a mechanical behavior less than of the resin to the grain sizes and for all formulations studied. Showed better results for the bending, reaching 25.3 MPa for the PG. The composite also showed be feasible for thermal applications, with thermal conductivity less than 0.21 W / m, ranking as insulation. In terms of homogeneity of the mixture, the most viable grain size is the PF, which also showed improved aesthetics and better processability. This composite can be used to make structures that do not require significant mechanical strength, such as tables, chairs, planks, and solar and wind prototypes, such as ovens and cookers and turbines blades.

Obtenção e caracterização de um compósito de matriz polimérica com carga de resíduos vegetal proveniente do sabugo de milho

The feasibility of using the corn cob to obtain a polymer matrix composite was studied. To obtain the bran, corncob passed the drying process in a solar dryer, and was subsequently triturated in forage and to obtain the different particle sizes, by sieving. Three different grain sizes were used: fine particles (FP) size between 0,10 and 2mm; sized particles (PM) with sizes between 2,10 and 3,35 mm; large particles (PG) sizes between 3,45 and 4,10 mm. Using 20% of residue relative to the resin, the test samples were constructed for characterization of the composite, taking into account thermal and mechanical parameters. The main advantage of the proposed composite is that it has a low density, below the relative resin, about 1.06 kg / m³ for the PG. The composite showed a mechanical behavior less than of the resin to the grain sizes and for all formulations studied. Showed better results for the bending, reaching 25.3 MPa for the PG. The composite also showed be feasible for thermal applications, with thermal conductivity less than 0.21 W / m, ranking as insulation. In terms of homogeneity of the mixture, the most viable grain size is the PF, which also showed improved aesthetics and better processability. This composite can be used to make structures that do not require significant mechanical strength, such as tables, chairs, planks, and solar and wind prototypes, such as ovens and cookers and turbines blades.

Obtenção, caracterização e utilização de um compósito com matriz de resina poliéster e carga de fibras de sisal

The constant search for sustainable alternatives has earned great effort of researchers in research and obtaining new materials, encouraging the rise of eco-friendly productive development and providing simple and practical solutions to economic profitability. In this sense, the use of materials derived from natural renewable sources, vegetables, has great potential applicability to sustainable development. As alternative materials plant fibers can be applied to production of a range of composite materials easing the use of materials derived from non-renewable this thesis were sisal mats used for achieving a composite matrix having as one orthophthalic polyester resin. The webs were subjected to surface treatment in boiling water for 15 minutes. The webs of sisal fibers used were, respectively, 5%, 10% and 15% of the composite weight. The composite was obtained and characterized mechanically and thermally to the chosen formulations. several plates of the composite to obtain the body of evidence for the characterization tests complying with the relevant rules were made. The obtained composites showed strength tensile and bending lower than the array, so it can be used where are required low load requests. The most significant result of the composite studied given to the impact energy absorption, far superior to the matrix used. Other properties were highlighted in oil absorption, and density. It proved the feasibility of obtaining the composite for the three formulations studied C5, C10 and C15 being the most feasible to C10. To demonstrate the feasibility of using composite were made a wall clock, a bench, a chair and a shelf, low mechanical stress structures. It was concluded that the sisal rugs exercised the load function in the composite.

Obtenção, caracterização e utilização de um compósito com matriz de resina poliéster e carga de fibras de sisal

The constant search for sustainable alternatives has earned great effort of researchers in research and obtaining new materials, encouraging the rise of eco-friendly productive development and providing simple and practical solutions to economic profitability. In this sense, the use of materials derived from natural renewable sources, vegetables, has great potential applicability to sustainable development. As alternative materials plant fibers can be applied to production of a range of composite materials easing the use of materials derived from non-renewable this thesis were sisal mats used for achieving a composite matrix having as one orthophthalic polyester resin. The webs were subjected to surface treatment in boiling water for 15 minutes. The webs of sisal fibers used were, respectively, 5%, 10% and 15% of the composite weight. The composite was obtained and characterized mechanically and thermally to the chosen formulations. several plates of the composite to obtain the body of evidence for the characterization tests complying with the relevant rules were made. The obtained composites showed strength tensile and bending lower than the array, so it can be used where are required low load requests. The most significant result of the composite studied given to the impact energy absorption, far superior to the matrix used. Other properties were highlighted in oil absorption, and density. It proved the feasibility of obtaining the composite for the three formulations studied C5, C10 and C15 being the most feasible to C10. To demonstrate the feasibility of using composite were made a wall clock, a bench, a chair and a shelf, low mechanical stress structures. It was concluded that the sisal rugs exercised the load function in the composite.

Obtenção e caracterização de um compósito de matriz polimérica com carga de bucha vegetal luffa cylindrica

Composite materials arise from the need for lighter materials and with bigger mechanical and thermal resistance. The difficulties of discard, recycling or reuse are currently environmental concerns and, therefore, they are study object of much researches. In this perspective the feasibility of using loofahs (Luffa Cylindrica) for obtainment of a polymeric matrix composite was studied. Six formulations, with 4, 5 and 6 treated layers and untreated, were tested. The loofahs were treated in boiling water to remove lignins, waxes and impurities present in the fibers. After that, they were dried in a direct exposure solar dryer. For the characterization of the composite, thermal (thermal conductivity, thermal capacity, thermal diffusivity and thermal resistivity), mechanical (tensile and bending resistance) and physicochemical (SEM, XRD, density, absorption and degradation) properties were determined. The proposed composite has as advantage the low fiber density, which is around 0.66 g/cm³ (almost half of the polyester resin matrix), resulting in an average composite density of around 1.17g/cm³, 6.0 % lower in relation to the matrix. The treatment carried out in the loofahs increased the mechanical strength of the composite and decreased the humidity absorption. The composite showed lower mechanical behavior than the matrix for all the formulations. The composite also demonstrated itself to be feasible for thermal applications, with a value of thermal conductivity of less than 0.159 W/m.K, ranking it as a good thermal insulator. For all formulations/settings a low adherence between fibers and matrix occurred, with the presence of cracks, showing the fragility due to low impregnation of the fiber by the matrix. This composite can be used to manufacture structures that do not require significant mechanical strength, such as solar prototypes, as ovens and stoves.