228 resultados para Rotational landslide


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This paper describes the UNESP robotic team in the medical trash collector task, proposed on the 5 rd IEEE Latin American Robots Competition in the LEGO category. We present our understanding of the task and discuss the proposed solution, focusing on the mechanical and computational issues of the robots. The mechanics is based on rigid body capability of transforming rotational into curvilinear movement. With respect to the computational control, the system is modeled as a reactive system with sequential transition of behaviors. A state-machine is proposed to allow this transition, and the synchronization of robotic states is guaranteed by the communication system. The proposed approach has shown itself capable of dealing with the high difficulty degree of this cooperative task. ©2006 IEEE.

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This work presents the implementation of the ultrasonic shear reflectance method for viscosity measurement of Newtonian liquids using wave mode conversion from longitudinal to shear waves and vice-versa. The method is based on measuring the complex reflection coefficient (magnitude and phase) at a solid-liquid interface. Viscosity measurements were made in the range from 1 to 3.5MHz at 22.5°C for automotive oil (SAE40) and at 15°C for olive oil. Moreover, measurements of the olive oil were also conducted in the range from 15 to 30°C at 3.5MHz. The experimental results agree with those provided by a rotational viscometer. © 2006 IEEE.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Three grazing management systems were compared to examine pasture decontamination of gastrointestinal nematode parasites (GIN) of sheep (Ovies aries) and cattle (Bos taurus). They consisted of sheep and cattle grazing paddocks alternately for 32, 96 or 192 days over 2 years. Pastureland (8.43 ha) was subdivided into six areas of eight paddocks each to produce an eight-paddock rotational grazing system. Every paddock was grazed for 4 days and then rested for 28 days. Sixty-six Ile de France ewes and 12 steers were randomly divided into three groups (22 sheep and four cattle per group). Each grazing system included a cattle area and a sheep area. Sheep and cattle interchanged areas every 32 days in system 1 (Group 1), every 96 days in system 2 (Group 2) and every 192 days in system 3 (Group 3). Fecal examination and larvae counting on pasture were performed every 32 days. During summer, winter and spring 2005, tracer lambs free of nematode infection were introduced into each sheep group and later sacrificed for quantification and identification of GIN species. All cattle were sacrificed for the same purpose. The main parasites found in tracer lambs were Haemonchus contortus and Trichostrongylus colubriformis, and in cattle, Haemonchus similis, Cooperia punctata and Oesophagostomum radiatum. Pasture contamination by sheep-infective GIN larvae was considerably reduced after 96 or 192 days of cattle grazing. Cross-infections between sheep and cattle GIN were not significant, which suggested that integrated grazing using such animals could be used for pasture decontamination. However, as effective anthelmintics were not available, decontamination was not sufficient for proper prophylaxis of GIN infections in Ile de France sheep, which are quite susceptible to such parasites. © 2007 Elsevier B.V. All rights reserved.

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A previous work showed that viscosity values measured high frequency by ultrasound agreed with the values at low frequency by the rotational viscometer when conditions are met, such as relatively low frequency viscosity. However, these conditions strongly reduce the range of the measurement cell. In order to obtain a measurement range and sensitivity high frequency must used, but it causes a frequency-dependent decrease on the viscosity values. This work introduces a new simple in order to represent this frequency-dependent behavior.model is based on the Maxwell model for viscoelastic , but using a variable parameter. This parameter has physical meaning because it represents the linear behavior the apparent elasticity measured along with the viscosity by .Automotive oils SAE 90 and SAE 250 at 22.5±0.5oC viscosities at low frequency of 0.6 and 6.7 Pa.s, respectively,tested in the range of 1-5 MHz. The model was used in to fit the obtained data using an algorithm of non-linear in Matlab. By including the viscosity at low frequency an unknown fitting parameter, it is possible to extrapolate its . Relative deviations between the values measured by the and extrapolated using the model for the SAE 90 and SAE 250 oils were 5.0% and 15.7%, respectively.©2008 IEEE.

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The city of Cubatão is a densely populated area with high industrial activity. In the area there are also important linear works as roads, railways, pipelines, aqueducts and lines of transmission of energy. The geological and geomorphological features of the municipality, combined with the human activities, make the site an area heavily prone to the landslides, so a region at high risk. In this work, landslide scars were extracted in aerial photos from 1985 and 1994, years that recorded a high incidence of landslides. Quantitative analysis of the relationship between the occurrence of scars and the forms of tracks were conducted, based on an intensive survey of scars in the region, represented by 2595 extracted scars, with the aim of contributing to a better understanding of the slipping processes in the Serra do Mar paulista and thus to the reduction of risks in the region. Achievements have concluded that the greatest percentage of slides in the region is linked to the strands straitght, followed by convex, which confirms previous studies conducted in the region, in a qualitative way or with a much lower number of scars.

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Steep slopes in subtropical zones are always at risk from landslides. The risk greatly increases when there is rapid, unplanned urban growth. This has happened at Ubatuba on the Brazilian coast - tourism-related development has forced local people into narrow valleys with steep slopes. In this article the authors describe how the hazard risk can be mapped, helping the local authorities to control the problem.

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This work was carried out to evaluate different frequencies of supplementation during the dry season. Forty-eight Nellore steers with 320 kg of initial live weight were fed with Brachiaria brizantha cv. Marandu pasture on a continuous stocking rate. The animals were submitted to following treatments: Daily supplementation and supplementation three times a week. The animals in both treatments received 7 kg of supplementation animal -1 weekly, and were weighted at 28-day intervals. The data were analyzed by the MIXED procedure in SAS (2004), with measurements repeated over time. The study observed average forage allowance of 4.2 tons of DM ha-1, with 3.5% CP, 82.24% NDF and 64.97% ADF. There was no difference (p < 0.01) among daily weight gains of animals who received daily supplementation and those received supplementation three times a week (0.23 and 0.13 kg day -1, respectively). Therefore, the supplementation intervals did not influence steer performance during the dry season.

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Cuttings return analysis is an important tool to detect and prevent problems during the petroleum well drilling process. Several measurements and tools have been developed for drilling problems detection, including mud logging, PWD and downhole torque information. Cuttings flow meters were developed in the past to provide information regarding cuttings return at the shale shakers. Their use, however, significantly impact the operation including rig space issues, interferences in geological analysis besides, additional personel required. This article proposes a non intrusive system to analyze the cuttings concentration at the shale shakers, which can indicate problems during drilling process, such as landslide, the collapse of the well borehole walls. Cuttings images are acquired by a high definition camera installed above the shakers and sent to a computer coupled with a data analysis system which aims the quantification and closure of a cuttings material balance in the well surface system domain. No additional people at the rigsite are required to operate the system. Modern Artificial intelligence techniques are used for pattern recognition and data analysis. Techniques include the Optimum-Path Forest (OPF), Artificial Neural Network using Multilayer Perceptrons (ANN-MLP), Support Vector Machines (SVM) and a Bayesian Classifier (BC). Field test results conducted on offshore floating vessels are presented. Results show the robustness of the proposed system, which can be also integrated with other data to improve the efficiency of drilling problems detection. Copyright 2010, IADC/SPE Drilling Conference and Exhibition.

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The C 2 * radical is used as a system probe tool to the reactive flow diagnostic, and it was chosen due to its large occurrence in plasma and combustion in aeronautics and aerospace applications. The rotational temperatures of C 2 * species were determined by the comparison between experimental and theoretical data. The simulation code was developed by the authors, using C++ language and the object oriented paradigm, and it includes a set of new tools that increase the efficacy of the C 2 * probe to determine the rotational temperature of the system. A brute force approach for the determination of spectral parameters was adopted in this version of the computer code. The statistical parameter c 2 was used as an objective criterion to determine the better match of experimental and synthesized spectra. The results showed that the program works even with low-quality experimental data, typically collected from in situ airborne compact apparatus. The technique was applied to flames of a Bunsen burner, and the rotational temperature of ca. 2100 K was calculated.

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Morphing aircraft have the ability to actively adapt and change their shape to achieve different missions efficiently. The development of morphing structures is deeply related with the ability to model precisely different designs in order to evaluate its characteristics. This paper addresses the dynamic modeling of a sectioned wing profile (morphing airfoil) connected by rotational joints (hinges). In this proposal, a pair of shape memory alloy (SMA) wires are connected to subsequent sections providing torque by reducing its length (changing airfoil camber). The dynamic model of the structure is presented for one pair of sections considering the system with one degree of freedom. The motion equations are solved using numerical techniques due the nonlinearities of the model. The numerical results are compared with experimental data and a discussion of how good this approach captures the physical phenomena associated with this problem. © The Society for Experimental Mechanics, Inc. 2012.

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This paper presents a study of a modeling scheme for the spin stabilized satellites attitude, entirely developed in terms of quaternion parametrization. The analysis includes numerical propagation of the rotational motion equation, considering the influence of the following torques: aerodynamic, gravity gradient, residual magnetic, eddy currents and the one due to the Lorentz force. Applications are developed considering the Brazilian Spin Stabilized Satellites SCD1 and SCD2, which are quite appropriated for verification and comparison of the theory with the real data generated and processed by the INPE's Satellite Control Center (SCC). The results show that for SCD1 and SCD2 the influence of the eddy current torque is bigger than the others ones, not only due to the orbit altitude, but also to other specific satellites characteristics. The influence of the torque due to Lorentz force is smaller than the others ones because of the dimension and the electrical charges of the SCD1 and SCD2. In all performed tests the errors remained within the dispersion range specified for the attitude determination system of INPE's SCC. The results show the feasibility of using the quaternion attitude parametrization for modeling the satellite dynamics of spin stabilized satellites.

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Municipal Plans of Risk Reducing (PMRR's) were produced in settlements in the municipalities of Itapecerica da Serra (SP) and Suzano (SP), covering areas at risk of landslides and washouts of banks of streams. The development of PMRR's provided the delimitation of areas of risk, the indication of intervention works in order to eliminate and / or reduce risks, and consequently an indication of the areas and priority sectors for implementation of intervention works. The prioritization of areas and sectors that should receive the works of reducing or eliminating risk was performed by an expert involved in risk mapping. Despite the specialist's judgment exercise caution, the decision regarding the priority sites for implementation of alternative interventions is subjective. Since there is no way to eliminate this subjectivity, the use of decision-making techniques is important to evaluate whether the expert's reasoning is consistent. One of the first techniques developed for multiple criteria is the AHP (Analytic Hierarchy Process). This paper describes the results of a research carried out in order to assess whether the use of Analytic Hierarchy Process contributes to the results of the indication of the areas and priority sectors for implementation of interventions can be considered more consistent than in situations where the priority occurs without the use of decision making techniques. Results were compared between the prioritization of interventions for implementation contained in PMRR's of Itapecerica da Serra and Suzano and those obtained from the use of Analytic Hierarchy Process (AHP). It was concluded that such techniques permits an evaluation of the expert's judgment is logically coherent, thus contributing to produce results more technically based.

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An analytical approach for spin stabilized attitude propagation is presented, considering the coupled effect of the aerodynamic torque and the gravity gradient torque. A spherical coordination system fixed in the satellite is used to locate the satellite spin axis in relation to the terrestrial equatorial system. The spin axis direction is specified by its right ascension and the declination angles and the equation of motion are described by these two angles and the magnitude of the spin velocity. An analytical averaging method is applied to obtain the mean torques over an orbital period. To compute the average components of both aerodynamic torque and the gravity gradient torque in the satellite body frame reference system, an average time in the fast varying orbit element, the mean anomaly, is utilized. Afterwards, the inclusion of such torques on the rotational motion differential equations of spin stabilized satellites yields conditions to derive an analytical solution. The pointing deviation evolution, that is, the deviation between the actual spin axis and the computed spin axis, is also availed. In order to validate the analytical approach, the theory developed has been applied for spin stabilized Brazilian satellite SCD1, which are quite appropriated for verification and comparison of the data generated and processed by the Satellite Control Center of the Brazil National Research Institute (INPE). Numerical simulations performed with data of Brazilian Satellite SCD1 show the period that the analytical solution can be used to the attitude propagation, within the dispersion range of the attitude determination system performance of Satellite Control Center of the Brazilian Research Institute.

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The objective of this study was to evaluate the effect of supplemental protein during the rainy season on body growth, ingestive behavior and reproductive performance of crossbred Gir x Holstein dairy heifers, with mean age of 21 ± 4.1 months and average initial body weight of 296.7 ± 57.3 kg, distributed in a completely randomized design with four treatments and six replicates per treatment. Heifers remained on Brachiaria brizantha cv. Marandu pasture, managed according to a rotational grazing system and, as treatment, it was supplemented with protein concentrate (34%, 43%, 56% and 66% BW) and level of supply of 0.30% body weight (BW). The animals were weighed and the mean weight of the lot was used for the calculation of adjustment of the amount of concentrate offered. Heifers that reached 330.0 kg of live weight were artificially inseminated and, 45 days after insemination, pregnancy diagnosis was performed for the calculation of pregnancy rate and age at conception. No significant difference of protein levels was observed on grazing, eating behavior, productive performance and age at conception of dairy heifers on pasture. The average daily weight gain of BW and age at conception were, on average, 0.907 kg/animal and 24.03 months, respectively.