cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.14329120.v1
title: Optimization of geometrically nonlinear truss structures under dynamic loading

description: Abstract The goal of this article is to present the formulation of the optimization problem of truss structures with geometric nonlinearity under dynamic loads and provide examples of this problem. The formulated optimization problem aims to determine the cross-sectional area of the bars that minimizes the weight of the structure, imposing constraints on nodal displacements and axial stresses. To solve this problem, computational routines were developed in MATLAB® using Sequential Quadratic Programming (SQP), the algorithm of which is available on MATLAB’s Optimization ToolboxTM. The nonlinear finite space truss element is described by an updated Lagrangian formulation. The geometric nonlinear dynamic analysis performed combines the Newmark method with Newton-Raphson iterations. It was validated by a comparison with solutions available in literature and with solutions generated by the ANSYS® software. Optimization examples of trusses under different dynamic loading were studied considering their geometric nonlinearity. The results indicate a significant reduction in structure weight for both undamped and damped cases.
DOI: 10.6084/m9.figshare.14329124.v1
title: Detection of seepage paths in small earth dams using the self-potential method (SP)

description: Abstract The application of geoelectric methods, such as induced polarization (IP), the electrical resistivity and the self-potential (SP), presents an important indirect study methodology in several areas of geology, such as mining, geotechnics and environmental geology. The present study deals with the results of the application of the self-potential method (SP) in small earth dams in the cities of Cordeirópolis and Ipeúna, both in the state of São Paulo. Studies of the Engineering of Dams intensified at the end of century XX, due to alarming number of dam disruptions. In Brazil, small dams are still the majority, around 90% of the total. This article presents results of surveys of the self-potential in two small dams, analyzing the flow of fluids, heat or ions inside the dams, as well as possible areas of percolation or water saturation. Three lines of 78 meters each were made with a spacing of 2 meters between the electrodes in the Cordeirópolis dam, and three lines of 122 meters each, spaced 2 meters between the electrodes in the Ipeúna dam. In both collections, the potential technique (or fixed base) was used. The collected data was worked on 2D maps of self-potential, which allowed to identify the zones with greater and smaller values of potential difference, preferential flow of the subsurface fluids in the areas, and possible problems in the structure of the dam (seepage paths), which could affect the physical integrity of the structure.
DOI: 10.6084/m9.figshare.14329126
title: Proposal of a method for service life prediction of a concrete structure: a case study

description: Abstract This article presents a method for service life prediction of concrete structures. The proposed method aims to estimate the performance of a concrete structure through its permeability to carbon dioxide penetration, in order to verify its accordance to Brazilian standards. This case study is based on an inspection made in an educational building in the city of Porto Alegre, Rio Grande do Sul, Brazil. Through carbon dioxide penetration, non-destructive and partial destructive tests, an estimated service life design for the concrete structure was elaborated. These tests were carried out in the parking lot because there is a greater vulnerability of the structure in terms of concentration of vehicles and lack of finishing, such as mortars or paints. The tests carried out showed that the selected concrete pieces were carbonated from 2.9 to 4.4 mm deep, a situation whose prognosis suggests a superior performance in accordance with the parameters set in ABNT NBR 15575:2013.
DOI: 10.6084/m9.figshare.14329127.v1
title: Aquamarine from Massangana batholith, Rondônia State: mineral chemistry and fluid inclusion data

description: Abstract Beryl is usually found in granite-pegmatite systems. The addition of chromophore elements (V, Cr, Mn, Fe) into the crystalline structure favors color changes in beryl and thus generates some of the world’s expensive gems such as emerald, morganite, heliodor and aquamarine. The Massangana polyphasic batholith is a well-known cassiterite, wolframite and gems deposit in the Rondônia state. These metals and blue-gems (topaz and aquamarine) are located in feldspar-rich pegmatite granite bodies. The aquamarine crystals show color ranging from light- to medium-blue and display concentric growth zones. Electron-probe microanalyses revealed that the Fe is the main chromophore element, occupying the octahedral Al-site, while Na had an important role in the charge balance, inserted in the channel sites together with H2O. The irregular supply of Fe and Na during the nucleation and growth of aquamarine was the main cause for the color change. A fluid inclusion study indicated that the aquamarine growth under an aqueous fluid system (H2O-NaCl), with low salinity, low density and total homogenization temperature between 243º-315º C, is compatible with final temperatures in the pegmatite pocket zone.
DOI: 10.6084/m9.figshare.14329132
title: Mineralogical characterization of copper lateritic ore from the Furnas deposit - Carajás, Brazil

description: Abstract Furnas is a small and not well-known copper sulfide deposit in the northern Carajás mineral province (Pará State, Brazil). Mineralogical and geochemical studies were performed on three weathered samples in order to verify the presence of copper in the lateritic minerals. According to these Cu-bearing minerals (malachite, e.g.), the weathered ore can be exploited. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Fourier Transformed Infrared (FTIR) spectroscopy analyses have shown that the copper is mainly associated to cryptomelane and to clay minerals and, although goethite composes from 40 to 50% of the samples (weight %), less than 0.1% of the total Cu is associated to it. Based on the results, the weathering sequence could be established; the alteration processes were responsible for the dissolution of the copper primary sulfides; the Cu released by these sulfides is, afterwards, incorporated in biotites and vermiculites, following the gneiss schistosity. Afterwards, the biotites altered to an interstratified 10-14 Å (biotite-smectite-vermiculite) and subsequently to an Al-Fe-Cu smectite (nontronite); finally, smectite was altered to kaolinite and the Cu was leached.
DOI: 10.6084/m9.figshare.14329145.v1
title: Influence of the pH regulator on the dolomite hydrophobization process

description: Abstract A study was carried out to investigate the combined effect of released ions in the pulp by pH regulator and mineral surface on dolomite flotation. The tests were carried out using a dolomite sample in a bench flotation cell with automatic froth remover. Zeta potential measurements, solution conductivity and FTIR analysis were done to support the interpretation of the results. The main reagents used for pH adjustment in the alkaline range (calcium hydroxide, sodium hydroxide, and sodium carbonate) were compared using amine or sodium oleate as collector. Dolomite is a sparingly soluble-type calcium mineral (as calcite, apatite, fluorite and scheelite), releasing differ ent amounts of calcium and magnesium ions in the pulp. Amine adsorbs mainly by a chemical complexation mechanism between the molecular specie RNH2 with calcium and magnesium ions present on the dolomite surface. In this system calcium hydroxide must be used because in addition to adjusting the pH it is a calcium ion supplier, thus increasing the collector adsorption. In turn, in the dolomite flotation with oleate, the pH must be regulated with soda ash that precipitates Ca2+ and Mg2+ as carbonate al lowing for higher adsorption of the collector.
DOI: 10.6084/m9.figshare.14329147.v1
title: Large strain consolidation analyses of fine tailings disposal in mining pits

description: Abstract Herein, three-dimensional analyses of large strain consolidation applied to tail ings disposal in mining pits is studied. The main goal is to estimate filling time and, ac cordingly, the capacity of the pit. Other useful results, such as dry density profiles and water pore pressure generation are also obtained. Two different slimes from the iron ore beneficiation are considered: a low plastic silt-clay material, and a 10 times more permeable silt-like soil. The consolidation constitutive relationships were obtained by performing HCT tests (Hydraulic Consolidation Test). The analyses were carried out using an algorithm that produces approximate solutions of the three-dimensional anal ysis using the computer program CONDES0. Two types of analyses were performed limiting the exact solution, one called upper bound and the other, lower bound. For purposes of this study, sensitivity analyses were also performed, including "instanta neous" consolidation, double drainage, and varying tailings production. Simulations of the co-disposal of the two different slimes were also addressed, where simultaneous rising and sharing of the tailings during reservoir occupation were sought by trial and error. In addition, prediction of the deposit surface profile in the long-term run was included. It was obtained from the filling of the pit with the Slime 01 for the lower bound 1054 days and for the upper bound, 1219 days. By comparing the slimes, Slime 02 offers the greater capacity. In the scenario of co-disposition, Slime 01 occupies 43% of the area and Slime 02, 57% of the area of the pit. Having already analyzed scenarios with constant and variable production of Slime 01 a greater capacity of the pit was ob tained for a constant production. Finally, there is a small difference in the pit capacity when the analyses are made considering the impermeable base and the permeable base.
DOI: 10.6084/m9.figshare.7510295
title: ACHIEVEMENT GOALS IN PHYSICAL EDUCATION AND SPORT AND PHYSICAL ACTIVITY IN LEISURE ON STUDENTS FROM SPAIN, COSTA RICA AND MEXICO

description: ABSTRACT: The objective of this study is to determine relationships between gender, behavior of practice, level of physical activity during leisure time and stages of change according to goal orientations of students in Secondary Education. The sample consisted of 2168 students, randomly selected to participate in a lengthy study, from Costa Rica (423), Mexico (408) and Spain (1337). With 1052 boys, 1037 girls and 79 of unknown gender, aged between 11 and 16 years (M = 12.49, SD = .81). It was concluded that variables analyzed in sport and physical activity during leisure time of students are positively associated with a higher perception of achievement goals. At the same time, according to literature reviewed, there is a higher prediction of practice. This data offers positive characteristics of Physical Education (PE), in addition, objectives of PE could be oriented to promote physical activity during leisure time among students.
DOI: 10.6084/m9.figshare.14329142.v1
title: Peculiarities of drilling and blasting in underground small-scale mines

description: Abstract Artisanal and Small-scale Mining (ASM) is a prominent activity in the extractive industry: considering only gold, it produces about 20% of the world market supply. Despite this fact, ASM is generally associated with the negative aspects of its environ mental impact, and operational research is generally neglected. This article empha sizes the peculiarity of the drilling and blasting systems of small underground mines in selected South American Countries. Such Countries, while having large mineral deposits and well recognized large-scale mining activities, at the same time still pres ent on their territory ASM activities that are archaic, highly inefficient and dangerous for the safety of its operators. This article documents drilling and blasting activities from gold mining in Ecuador and Chile. First, described are the outdated and often non-rational techniques employed by miners, to provide a general framework of the current methods. Then, shown is what can be improved and how the current methods can be modified. Finally, some field applications and the comparisons of the results ob tained are presented. One case shows how blast pull efficiency can be increased from 82% to 98% by changing non-rational applications of explosive products to rational, scientific-based employment. Another case shows how, by rationalizing blast designs, drilling and blasting costs can be reduced by 9% per month, the advance by blasting increased by 29% and the pull efficiency increased from 70% to 90%. Finally, it is concluded that examples of application show how operational improvements are eas ily applicable in the field, relying only on tools and resources of artisanal mining, but combining solid engineering bases with confidence-gain and respect for the experience of the miners.
DOI: 10.6084/m9.figshare.7510271.v1
title: INFLUENCES OF GENDER ON ATTENTION AND LEARNING OF MOTOR SKILLS

description: ABSTRACT The aim of this study was to investigate the influence of focus of attention in learning of boys and girls, in a balance task. Seventy-four children (38 girls and 36 boys) with a mean age of 8,03 years participated in the study. The task involved participants to ride a Pedalo, without support. The participants were divided in six groups, three for each sex, in relation to the instruction: Proximal External Focus (FP); Distal External Focus (FD); Control (C). The results showed that, in acquisition phase, boys outperformed girls (p=0,022). In transfers tests, only T2 showed a significant difference (p=0,014), with better performance of boys and, for the focus of attention, the distant external focus was higher than the control group in both transfers tests (p=0,034; p=0,018). Thus, directing the focus of attention externally, at a greater distance from the body, can enhance learning of boys.
DOI: 10.6084/m9.figshare.7510316
title: PRACTICES AND REPRESENTATIONS OF SCHOOL PHYSICAL EDUCATION IN DAILY LESSON PLANNERS IN SINOP-MT (1979-2009)

description: ABSTRACT: This paper aims to identify the characteristics of the Physical Education classes at the state school Nilza Oliveira Pipino in Sinop-MT, reported in the daily lesson planners between 1979 and 2009. There was a historical research of documental type, identifying the main descriptions in the daily lesson planners of Physical Education. It was verified that there was progress in the development of classes, but this one was lower than to the conceptual evolution of the area because of apparent disharmony between new proposals and debates and what occurred during the established historical period. It was possible to identify tecnicists remnants in the practices described.
DOI: 10.6084/m9.figshare.7510295.v1
title: ACHIEVEMENT GOALS IN PHYSICAL EDUCATION AND SPORT AND PHYSICAL ACTIVITY IN LEISURE ON STUDENTS FROM SPAIN, COSTA RICA AND MEXICO

description: ABSTRACT: The objective of this study is to determine relationships between gender, behavior of practice, level of physical activity during leisure time and stages of change according to goal orientations of students in Secondary Education. The sample consisted of 2168 students, randomly selected to participate in a lengthy study, from Costa Rica (423), Mexico (408) and Spain (1337). With 1052 boys, 1037 girls and 79 of unknown gender, aged between 11 and 16 years (M = 12.49, SD = .81). It was concluded that variables analyzed in sport and physical activity during leisure time of students are positively associated with a higher perception of achievement goals. At the same time, according to literature reviewed, there is a higher prediction of practice. This data offers positive characteristics of Physical Education (PE), in addition, objectives of PE could be oriented to promote physical activity during leisure time among students.
DOI: 10.6084/m9.figshare.7516970
title: PSYCHOMETRIC PROPERTIES OF THE ATHLETE BURNOUT QUESTIONNAIRE FOR YOUNG BRAZILIAN ATHLETES

description: ABSTRACT The objective of this study was to identify the psychometric properties of the Athlete Burnout Questionnaire (ABQ) for young Brazilian athletes. The questionnaire was administered to a sample of 1,217 young athletes (410 girls and 807 boys) aged 12 to 17 years. Exploratory factor analysis, followed by confirmatory factor analysis, was performed to identify the initial psychometric properties. Cronbach's alpha coefficient was used to assess the internal consistency of each factor of the ABQ associated with burnout. The results confirmed the structure of the three originally proposed factors (physical/emotional exhaustion, reduced sense of personal accomplishment, and sport devaluation) based on the following statistical measures: χ2/d.f. = 2.89, CFI = 0.930, GFI = 0.928, AGFI = 0.937, and RMSR = 0.068 [CI90%: 0.065 - 0.072]. Cronbach's alpha ranged from 0.80 to 0.87. In conclusion, the psychometric qualities of the ABQ were satisfactory for young Brazilian athletes, thus permitting the application of the questionnaire in future studies in Brazil.
DOI: 10.6084/m9.figshare.7510277.v1
title: INFLUENCE OF AN INTERVENTION USING PRACTICES RANDOM AND BLOCKED IN THE PERFORMANCE OF OBJECT CONTROL SKILLS

description: ABSTRACT Based on the Contextual Interference Effect (EIC), we investigated the influence of a motor intervention in the performance of object control skills. Participated 60 children of six and seven years old, divided into three groups: random practice (GR), blocked practice (GB), control group (CG). The skills were tested with the Test of Gross Motor Development - 2 (TGMD-2). The experimental design included the periods: pre-test, practice sessions (12), post-test. GR and GB took part of the intervention. Descriptive analysis demonstrated that children showed adequate performance, according TGMD-2. In post-test, the Kruskal-Wallis test detected a significant difference between groups. The Mann-Whitney test was indicated that GR was superior to GB. The intragroup analysis, using Wilcoxon test, showed significant improvement in GR (p = 0.0004) and GB (p = 0.004). We conclude that the intervention improved the motor performance of object control skills, and GR showed the best performance in the post-test.
DOI: 10.6084/m9.figshare.7516970.v1
title: PSYCHOMETRIC PROPERTIES OF THE ATHLETE BURNOUT QUESTIONNAIRE FOR YOUNG BRAZILIAN ATHLETES

description: ABSTRACT The objective of this study was to identify the psychometric properties of the Athlete Burnout Questionnaire (ABQ) for young Brazilian athletes. The questionnaire was administered to a sample of 1,217 young athletes (410 girls and 807 boys) aged 12 to 17 years. Exploratory factor analysis, followed by confirmatory factor analysis, was performed to identify the initial psychometric properties. Cronbach's alpha coefficient was used to assess the internal consistency of each factor of the ABQ associated with burnout. The results confirmed the structure of the three originally proposed factors (physical/emotional exhaustion, reduced sense of personal accomplishment, and sport devaluation) based on the following statistical measures: χ2/d.f. = 2.89, CFI = 0.930, GFI = 0.928, AGFI = 0.937, and RMSR = 0.068 [CI90%: 0.065 - 0.072]. Cronbach's alpha ranged from 0.80 to 0.87. In conclusion, the psychometric qualities of the ABQ were satisfactory for young Brazilian athletes, thus permitting the application of the questionnaire in future studies in Brazil.
DOI: 10.6084/m9.figshare.7516763.v1
title: ANALYSIS OF THE TACTICAL BEHAVIOR OF YOUTH ACADEMY SOCCER PLAYERS

description: ABSTRACT The aim of this study was to compare the tactical behavior efficiency between soccer players from different age levels. The sample comprised 400 players from four age groups (Under-11, -13, -15, and -17), who performed 23,855 tactical actions. Players' tactical behavior efficiency was assessed through FUT-SAT. Statistical procedures included descriptive analysis and the tests Kolmogorov-Smirnov, Kruskal-Wallis and Mann-Whitney. The significance level adopted was p&lt;0.05. Results indicated that the tactical behavior efficiency tends to increase over time, except for the U-15 age level, that displayed an accentuated drop in relation to the others. It is concluded that the efficiency of tactical behavior of the players in soccer displayed differences across different age levels.
DOI: 10.6084/m9.figshare.7516760.v1
title: DO DIFFERENT WEIGHT TRAINING METHODS CHANGE THE APPETITE OF YOUNG ADULTS?

description: ABSTRACT This study assessed the effects of different weight training (WT) on appetite feeling in trained men. The sample consisted of 10 men aged between 18 to 29 years old. There were two experimental sessions with a wash out of seven days: in the circuit weight training (CWT), exercises were performed by alternating segment in stations, while during the traditional method (TM) exercises were performed in consecutive series. Both methods had the same total workload. The perception of hunger and perspective of food intake were measured in moments: at baseline, after exercise and 1 hour. Differences only in feelings of hunger among moment (p&gt;0.05) were showed, and there were not differences between methods or effect of interaction (p&gt;0.05). Thus, we concluded that both training methods are not altering the feeling of hunger or perspective of food intake, however the magnitude to raise is higher in TM.
DOI: 10.6084/m9.figshare.14329148
title: Seismic signature of mudflow tremor resulted from Brumadinho (Brazil) tailings dam failure

description: Abstract Mudflow is often associated with seismic activities. The present study applied a seismic based detection of the surface waves generated by the mudflow of Brumadinho dam collapse using records of Brazilian Seismographic Network. The signal envelope and time-frequency spectrograms of the mudflow signals were used in the analysis. As a result, the mudflow signals were successfully detected from the data recorded at a nearby seismic station. The findings of this study provide a good basis for future research to develop a flood early warning system based on cost-effective, remote and contentious seismic monitoring approaches.
DOI: 10.6084/m9.figshare.7510271
title: INFLUENCES OF GENDER ON ATTENTION AND LEARNING OF MOTOR SKILLS

description: ABSTRACT The aim of this study was to investigate the influence of focus of attention in learning of boys and girls, in a balance task. Seventy-four children (38 girls and 36 boys) with a mean age of 8,03 years participated in the study. The task involved participants to ride a Pedalo, without support. The participants were divided in six groups, three for each sex, in relation to the instruction: Proximal External Focus (FP); Distal External Focus (FD); Control (C). The results showed that, in acquisition phase, boys outperformed girls (p=0,022). In transfers tests, only T2 showed a significant difference (p=0,014), with better performance of boys and, for the focus of attention, the distant external focus was higher than the control group in both transfers tests (p=0,034; p=0,018). Thus, directing the focus of attention externally, at a greater distance from the body, can enhance learning of boys.