cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.7273790.v1
title: Unmanned Aerial Vehicle Propagation Datalink Tool Based on a Hybrid Multiscale Modeling

description: ABSTRACT: This article presents a hybrid computational method to address the datalink characteristics of an Unmanned Aerial Vehicle (UAV) relay. It uses the 3D far-field gain data from the antennas (UAV and ground station), separately computed or based on available measurements as inputs, and then applies the 2-Ray propagation model, taking into consideration the ground permittivity and the respective antenna heights. By doing so, different numerical approaches cover the two different physical scales. Since the installed antennas (i.e. antennas considered placed on the UAV fuselage) performances are considered, a higher reliability can be achieved with the covered procedure, at lower costs when compared to field measurements. Results for different example scenarios are presented and discussed.
DOI: 10.6084/m9.figshare.6858074.v1
title: A New Approach for Robust Design Optimization Based on the Concepts of Fuzzy Logic and Preference Function

description: ABSTRACT: In this study, an efficient methodology is proposed for robust design optimization by using preference function and fuzzy logic concepts. In this method, the experience of experts is used as an important source of information during the design optimization process. The case study in this research is wing design optimization of Boeing 747. Optimization problem has two objective functions (wing weight and wing drag) so that they are transformed into new forms of objective functions based on fuzzy preference functions. Design constraints include transformation of fuel tank volume and lift coefficient into new constraints based on fuzzy preference function. The considered uncertainties are cruise velocity and altitude, which Monte Carlo simulation method is used for modeling them. The non-dominated sorting genetic algorithm is used as the optimization algorithm that can generate set of solutions as Pareto frontier. Ultimate distance concept is used for selecting the best solution among Pareto frontier. The results of the probabilistic analysis show that the obtained configuration is less sensitive to uncertainties.
DOI: 10.6084/m9.figshare.7273808.v1
title: Study of Gas Turbulent Dispersion Process in the Alcântara Launch Center

description: ABSTRACT: The Alcântara Launch Center (ALC) is the Brazilian gate to the space located at the north coast of Maranhão State, close to the Equator. Topographical local characteristics modify the parameters of incident atmospheric winds and it can cause great influence on the gas dispersion process. In this work, detailed scale models of the ALC region was experimentally evaluated using a wind tunnel. The topographical scale models were built where mean and fluctuating flow characteristics were analysed in order to understand the real behaviour of ALC winds and then, simulations of the effluent dispersion process were made using these scale models. The wind velocity was measured by a hot wire anemometer and the concentration fields in the proximities of a gas emission source were analysed by an aspirating probe connected to the anemometer system. The results obtained show similarity with numerical outputs from previous study in the case of the emission at ground level. A coherent behaviour with the physic of the phenomena was observed for the case of emission downward.
DOI: 10.6084/m9.figshare.6858074
title: A New Approach for Robust Design Optimization Based on the Concepts of Fuzzy Logic and Preference Function

description: ABSTRACT: In this study, an efficient methodology is proposed for robust design optimization by using preference function and fuzzy logic concepts. In this method, the experience of experts is used as an important source of information during the design optimization process. The case study in this research is wing design optimization of Boeing 747. Optimization problem has two objective functions (wing weight and wing drag) so that they are transformed into new forms of objective functions based on fuzzy preference functions. Design constraints include transformation of fuel tank volume and lift coefficient into new constraints based on fuzzy preference function. The considered uncertainties are cruise velocity and altitude, which Monte Carlo simulation method is used for modeling them. The non-dominated sorting genetic algorithm is used as the optimization algorithm that can generate set of solutions as Pareto frontier. Ultimate distance concept is used for selecting the best solution among Pareto frontier. The results of the probabilistic analysis show that the obtained configuration is less sensitive to uncertainties.
DOI: 10.6084/m9.figshare.7518242
title: Validation of rainfall data estimated by GPM satellite on Southern Amazon region

description: Abstract Rainfall is a meteorological variable of great importance for hydric balance and for weather studies. Rainfall estimation, carried out by satellites, has increased the climatological dataset related to precipitation. However, the accuracy of these data is questionable. This paper aimed to validate the estimates done by the Global Precipitation Measurement (GPM) satellite for the mesoregion of Southern Amazonas State, Brazil. The surface data were collected by the National Water Agency - ANA and National Institute of Meteorology - INMET, and is available at both institutions’ websites. The satellite precipitation data were accessed directly from the NASA webpage. Statistical analysis of Pearson correlation was used, as well as the Willmott’s “d” index and errors from the MAE (Mean Absolute Error) and RMSE (Root Mean Square Error). The GPM satellite satisfactorily estimated the precipitation, once it had correlations above 73% and high Willmott coefficients (between 0.86 and 0.97). The MAE and RMSE showed values that varied from 36.50 mm to 72.49 mm and 13.81 mm to 71.76 mm, respectively. Seasonal rain variations are represented accordingly. In some cases, either an underestimation or an overestimation of the rain data was observed. In the yearly totals, a high rate of similarity between the estimated and measured values was observed. We concluded that the GPM-based multi-satellite precipitation estimates can be used, even though they are not 100% reliable. However, adjustments in calibration for the region are necessary and recommended.
DOI: 10.6084/m9.figshare.7273808
title: Study of Gas Turbulent Dispersion Process in the Alcântara Launch Center

description: ABSTRACT: The Alcântara Launch Center (ALC) is the Brazilian gate to the space located at the north coast of Maranhão State, close to the Equator. Topographical local characteristics modify the parameters of incident atmospheric winds and it can cause great influence on the gas dispersion process. In this work, detailed scale models of the ALC region was experimentally evaluated using a wind tunnel. The topographical scale models were built where mean and fluctuating flow characteristics were analysed in order to understand the real behaviour of ALC winds and then, simulations of the effluent dispersion process were made using these scale models. The wind velocity was measured by a hot wire anemometer and the concentration fields in the proximities of a gas emission source were analysed by an aspirating probe connected to the anemometer system. The results obtained show similarity with numerical outputs from previous study in the case of the emission at ground level. A coherent behaviour with the physic of the phenomena was observed for the case of emission downward.
DOI: 10.6084/m9.figshare.7518242.v1
title: Validation of rainfall data estimated by GPM satellite on Southern Amazon region

description: Abstract Rainfall is a meteorological variable of great importance for hydric balance and for weather studies. Rainfall estimation, carried out by satellites, has increased the climatological dataset related to precipitation. However, the accuracy of these data is questionable. This paper aimed to validate the estimates done by the Global Precipitation Measurement (GPM) satellite for the mesoregion of Southern Amazonas State, Brazil. The surface data were collected by the National Water Agency - ANA and National Institute of Meteorology - INMET, and is available at both institutions’ websites. The satellite precipitation data were accessed directly from the NASA webpage. Statistical analysis of Pearson correlation was used, as well as the Willmott’s “d” index and errors from the MAE (Mean Absolute Error) and RMSE (Root Mean Square Error). The GPM satellite satisfactorily estimated the precipitation, once it had correlations above 73% and high Willmott coefficients (between 0.86 and 0.97). The MAE and RMSE showed values that varied from 36.50 mm to 72.49 mm and 13.81 mm to 71.76 mm, respectively. Seasonal rain variations are represented accordingly. In some cases, either an underestimation or an overestimation of the rain data was observed. In the yearly totals, a high rate of similarity between the estimated and measured values was observed. We concluded that the GPM-based multi-satellite precipitation estimates can be used, even though they are not 100% reliable. However, adjustments in calibration for the region are necessary and recommended.
DOI: 10.6084/m9.figshare.7336601.v1
title: Design of Attitude Control Servomechanisms with Fluid Ring and CMG for Rigid Satellite

description: ABSTRACT: Satellites cover a wide range of space missions as remote sensing. Accomplishment of the mission depends on satellite's stability maintenance and direction. The main task of the attitude control system is to provide stability to the satellite against external disturbances. Such perturbations are caused due to aerodynamic drag, solar radiation and magnetic field. The attitude dynamics model and the development of a controller to stabilize the three degrees of freedom rotational angles are quite important steps in the design of satellites. Although there are several actuators to provide attitude determination and control, a novel type is considered in this paper. This new actuator is the fluid contained inside one or more rings and fluid flow supplied by pump. The required torque control made by change of angular velocity of fluid. In this paper, the satellite is considered rigid and nonlinear dynamics equations were written. Because of the importance of satellite mission, the failure of the pyramid-shaped satellite with an additional ring fluid will be discussed. Satellite attitude control is carried out with an Euler angle errors control law. The performance of this actuator is compared with moment control gyro and their advantages on to each other have been described.
DOI: 10.6084/m9.figshare.7507829
title: Homeopathic medicines in the treatment and prevention of dengue: a review

description: Background: Dengue is an important tropical disease with an estimated number of 50 to 100 million cases per year. Currently, there are no specific treatments or a vaccine available for the control of dengue disease, but homeopathic practitioners suggest that homeopathic formulations are useful to prevent and treat symptoms of dengue.Objective: To present a review of literature that seeks to identify and summarize all studies that had investigated the utility of the homeopathic medicines in the treatment and prevention of dengue.Methods: We conducted a systematic search of published scientific articles in the following databases: PubMed, LILACS, Scopus, ISI Web of Science, The Cochrane Library, PsycInfo and SciELO, employing English, Portuguese and Spanish language. The search terms used were "dengue" and "homeopathy".Results: It was found only one randomized controlled double-blind clinical trial and two trials of community. However, these studies do not provided reliable evidences of therapeutic or prophylactic efficacy of homeopathic formulations.Conclusion: To date, due to the lack of randomized, double-blind controlled and well conducted studies in sufficient numbers, there are no clear evidences of the usefulness of homeopathic medicines for the treatment and prevention of dengue. Thus, the usual measures and well known employed in the primary prevention of disease should not be replaced by homeopathic formulations.
DOI: 10.6084/m9.figshare.7507829.v1
title: Homeopathic medicines in the treatment and prevention of dengue: a review

description: Background: Dengue is an important tropical disease with an estimated number of 50 to 100 million cases per year. Currently, there are no specific treatments or a vaccine available for the control of dengue disease, but homeopathic practitioners suggest that homeopathic formulations are useful to prevent and treat symptoms of dengue.Objective: To present a review of literature that seeks to identify and summarize all studies that had investigated the utility of the homeopathic medicines in the treatment and prevention of dengue.Methods: We conducted a systematic search of published scientific articles in the following databases: PubMed, LILACS, Scopus, ISI Web of Science, The Cochrane Library, PsycInfo and SciELO, employing English, Portuguese and Spanish language. The search terms used were "dengue" and "homeopathy".Results: It was found only one randomized controlled double-blind clinical trial and two trials of community. However, these studies do not provided reliable evidences of therapeutic or prophylactic efficacy of homeopathic formulations.Conclusion: To date, due to the lack of randomized, double-blind controlled and well conducted studies in sufficient numbers, there are no clear evidences of the usefulness of homeopathic medicines for the treatment and prevention of dengue. Thus, the usual measures and well known employed in the primary prevention of disease should not be replaced by homeopathic formulations.
DOI: 10.6084/m9.figshare.7304669
title: Improvement of Airfoils Aerodynamic Efficiency by Thermal Camber Phenomenon at Low Reynolds Number

description: ABSTRACT: In this research, viscous, laminar and steady flow around symmetric and non-symmetric airfoils is simulated at Low Reynolds Number (LRN). Navier-Stokes (N-S) equations are discretized by Finite Volume Method (FVM) and are solved by the SIMPLE algorithm in an open source software, namely OpenFOAM. The main objective of this paper is the introduction of the thermal camber phenomenon. This phenomenon is used to improve the aerodynamic performance. Hence, a symmetric airfoil, like NACA0012, with thermal camber is compared with the airfoils with the physical camber, including NACA2412 and NACA4412, to specify which camber type has more effects on the aerodynamic efficiency. Furthermore, various temperatures are tested in order to find the optimum condition. After validation, results indicated that cooling upper surface and heating lower surface, namely thermal camber, generate lift force and improve aerodynamic performance for symmetric airfoils at a 0° Angle of Attack (AOA). These improvements are more than the airfoils with physical camber. Also, when this method is applied to the NACA2412 and NACA4412 airfoils, lift to drag coefficient ratio will increase more than the condition with only cooling or heating the surfaces.
DOI: 10.6084/m9.figshare.7336601
title: Design of Attitude Control Servomechanisms with Fluid Ring and CMG for Rigid Satellite

description: ABSTRACT: Satellites cover a wide range of space missions as remote sensing. Accomplishment of the mission depends on satellite's stability maintenance and direction. The main task of the attitude control system is to provide stability to the satellite against external disturbances. Such perturbations are caused due to aerodynamic drag, solar radiation and magnetic field. The attitude dynamics model and the development of a controller to stabilize the three degrees of freedom rotational angles are quite important steps in the design of satellites. Although there are several actuators to provide attitude determination and control, a novel type is considered in this paper. This new actuator is the fluid contained inside one or more rings and fluid flow supplied by pump. The required torque control made by change of angular velocity of fluid. In this paper, the satellite is considered rigid and nonlinear dynamics equations were written. Because of the importance of satellite mission, the failure of the pyramid-shaped satellite with an additional ring fluid will be discussed. Satellite attitude control is carried out with an Euler angle errors control law. The performance of this actuator is compared with moment control gyro and their advantages on to each other have been described.
DOI: 10.6084/m9.figshare.7304669.v1
title: Improvement of Airfoils Aerodynamic Efficiency by Thermal Camber Phenomenon at Low Reynolds Number

description: ABSTRACT: In this research, viscous, laminar and steady flow around symmetric and non-symmetric airfoils is simulated at Low Reynolds Number (LRN). Navier-Stokes (N-S) equations are discretized by Finite Volume Method (FVM) and are solved by the SIMPLE algorithm in an open source software, namely OpenFOAM. The main objective of this paper is the introduction of the thermal camber phenomenon. This phenomenon is used to improve the aerodynamic performance. Hence, a symmetric airfoil, like NACA0012, with thermal camber is compared with the airfoils with the physical camber, including NACA2412 and NACA4412, to specify which camber type has more effects on the aerodynamic efficiency. Furthermore, various temperatures are tested in order to find the optimum condition. After validation, results indicated that cooling upper surface and heating lower surface, namely thermal camber, generate lift force and improve aerodynamic performance for symmetric airfoils at a 0° Angle of Attack (AOA). These improvements are more than the airfoils with physical camber. Also, when this method is applied to the NACA2412 and NACA4412 airfoils, lift to drag coefficient ratio will increase more than the condition with only cooling or heating the surfaces.
DOI: 10.6084/m9.figshare.7517168.v1
title: Histopathological and hematological biomarkers in tambaqui Colossoma macropomum (Cuvier, 1816) from an environmental protection area of Maranhão, Brazil

description: Abstract This study analyzed histopathological (gill lesions) and hematological (erythrocyte abnormalities) changes in tambaqui (Colossoma macropomum) in order to evaluate the water quality of fish farms in the Environmental Protection Area (EPA) of Maracanã, Maranhão, Brazil. Specimens of tambaqui were captured in two areas of EPA: A1) Serena Lagoon, and A2) River Ambude, in two seasonal periods, rainy and dry. For the hematological analyses, slides were made from the blood smear collected from the branchial arch of the fish. In the laboratory, the gills of each specimen were fixed in 10% formalin and maintained in 70% alcohol until the usual histological technique. The branchial changes were more frequent during the dry season in both areas. In the fish collection in A2, the following changes were noted: mucosal cells (78%), lamellar fusion (90%), lamellar disorganization (100%), lamellar narrowing (100%), and epithelial displacement (96%). In the fish collection in A1, the main lesions were: aneurysm (88%), dilation of the capillaries (82%), rupture of the capillaries (60%). In addition, nuclear alterations, such as binucleate cells (BC), cells with an evaginated nucleus (CEN) and cells with a lobulated carved nucleus (CLCN), were observed in the fish from both areas. The frequency of abnormalities was higher in the fish from A2 (74%) when compared to the fish from A1 (26%). In conclusion, we found that these alterations proved to be sensitive biomarkers capable of differentiating water quality and fish health status in the two systems in the Maracanã EPA.
DOI: 10.6084/m9.figshare.7517168
title: Histopathological and hematological biomarkers in tambaqui Colossoma macropomum (Cuvier, 1816) from an environmental protection area of Maranhão, Brazil

description: Abstract This study analyzed histopathological (gill lesions) and hematological (erythrocyte abnormalities) changes in tambaqui (Colossoma macropomum) in order to evaluate the water quality of fish farms in the Environmental Protection Area (EPA) of Maracanã, Maranhão, Brazil. Specimens of tambaqui were captured in two areas of EPA: A1) Serena Lagoon, and A2) River Ambude, in two seasonal periods, rainy and dry. For the hematological analyses, slides were made from the blood smear collected from the branchial arch of the fish. In the laboratory, the gills of each specimen were fixed in 10% formalin and maintained in 70% alcohol until the usual histological technique. The branchial changes were more frequent during the dry season in both areas. In the fish collection in A2, the following changes were noted: mucosal cells (78%), lamellar fusion (90%), lamellar disorganization (100%), lamellar narrowing (100%), and epithelial displacement (96%). In the fish collection in A1, the main lesions were: aneurysm (88%), dilation of the capillaries (82%), rupture of the capillaries (60%). In addition, nuclear alterations, such as binucleate cells (BC), cells with an evaginated nucleus (CEN) and cells with a lobulated carved nucleus (CLCN), were observed in the fish from both areas. The frequency of abnormalities was higher in the fish from A2 (74%) when compared to the fish from A1 (26%). In conclusion, we found that these alterations proved to be sensitive biomarkers capable of differentiating water quality and fish health status in the two systems in the Maracanã EPA.
DOI: 10.6084/m9.figshare.7517165
title: Defining environmental conservation levels considering anthropic activity in the Uberaba River Basin protected area

description: Abstract Environmental conservation of river basins in general is essential for water quality and ecological maintenance, especially in spring areas. Despite being characterized as a Conservation Unit (CU) of Sustainable Use (SU), the Uberaba River Basin highlands are highly influenced by anthropic activities. The aim of this study was to determine different levels of conservation required to maintain environmental quality. The Multicriteria evaluation method was used as follows: i) applied fuzzy membership functions to standardization of the continuous data values or reclassified when categorical criteria; (ii) established criteria ranking through the pairwise relative importance comparison approach by the Analytical Hierarchy Process (AHP) method and; (iii) performed Weighted Linear Combination (WLC). The selected criteria were maps of the: land cover obtained by supervised classification of a satellite image, with 94% of Kappa Index of Agreement (KIA); soil types, slope; distances from rivers, roads; railways and urban limits. A main outcome of the criteria evaluated is a map of continuous data values expressing distinct levels of environmental conservation requirements. The highest values that express the need for conservation occurred near the ridgetop, corresponding to forest land cover, high slope and hydromorphic soils. The lowest values were observed in the peri-urban areas, in more stable soil and soil cover with a higher degree of occupation. It is concluded that the resulting map can assist in decision-making regarding proper management of the area, to achieve sustainability in the application of occupation policies.