309 research outputs found

    A Ranking Method to Prioritize VFR Airports to Be Provided With Instrument Approach Procedures

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    The primary purpose of this work is to investigate the necessity of a more comprehensive and systematic method to prioritize airports to be provided with instrument approach and landing procedures in the Brazilian air transportation landscape. An overview of the main contributors to risks associated with the approach and landing phases is provided, covering the most important aspects of unstable approaches and CFIT events. Considering the emergence of Terrain Awareness and Alerting Systems (TAWS), the role of its contribution to safety is discussed, as well as the certification context related to the design, installation, and operation of those systems. A ranking method is developed based on the analysis of TAWS alert events in several Brazilian airports. The method results in a ranking list of airports eligible for instrument procedures and points to objective means to improve safety, accessibility, and efficiency on the flight operations to those locations

    Indicadores econômicos da produção orgânica de minitomate em casas de vegetação

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    Financial profitability is a factor as important as quantifying production using new technologies. This study was installed to evaluate short and long term financial viability of organic production of cherry tomatoes. Plants were grown in a greenhouse under diverse technological degrees for partial control of micrometeorological elements. The experiment was carried out at the experimental field FEAGRI/UNICAMP in three greenhouses with automated mechanical ventilation systems, evaporative cooling and thermo reflective screen. We cultivated Carolina cultivar in a spacing of 0.5x0.9 m, each plant conducted with two stems, under organic production and fertilization management. The average of production data of treatments {three greenhouses (A= climate-controlled, B= mobile screen and C= fixed screen), two cultivation systems (pots and soil beds) and five biofertilizer doses (0, 50, 100, 150, and 200%)} were evaluated using joint analysis. Thus, the economic indicators {cost benefit ratio (B/C), net present value (NPV), internal rate of return (IRR) and Payback (PV)} were evaluated through revenues and production costs. The best alternative to net monthly cycle profitability (500 m2) was approximately 1 and 1.5 minimum wage with and without particular labor, respectively, associated with the greenhouse of medium technological level, using soil bed cultivation system. The economic viability of the project in long-term interest rates above 3% (a.a) was consistent, but the payback period even with a rate of 1% a.a was high (6.54 years) in financing conditions.362246252A rentabilidade financeira é um fator tão importante quanto quantificar a produção utilizando novas tecnologias. Assim, objetivou-se analisar em curto e longo prazo a rentabilidade financeira da produção orgânica de minitomates em casas de vegetação com diferentes graus tecnológicos de controle parcial dos elementos micrometeorológicos. O experimento foi desenvolvido no campo experimental da FEAGRI/UNICAMP (SP) em três casas de vegetação com sistemas automatizados de ventilação mecânica, resfriamento evaporativo e tela termorrefletora, sendo estas cultivadas com a cultivar Carolina em espaçamento 0,5x0,9 m em duas hastes, e manejo da produção e adubação orgânica. As médias dos dados de produção dos tratamentos {três casas de vegetação (A= climatizada, B= tela móvel e C= tela fixa), duas formas de cultivo (vasos e canteiros) e cinco doses de biofertilizante (0, 50, 100, 150, e 200%)} foram avaliadas em análise conjunta. Assim, avaliou-se através das receitas e custos de produção os indicadores econômicos {relação benefício custo (B/C), valor presente líquido (VPL), Taxa interna de retorno (TIR) e Payback (PV)}. De acordo com os resultados, a melhor alternativa de rentabilidade líquida mensal ciclo (500 m2) foi de aproximadamente 1 e 1,5 salários mínimo para a condição com e sem mão de obra particular, respectivamente, associado à casa de vegetação de médio grau tecnológico, utilizando a forma de cultivo em canteiros. A viabilidade econômica do projeto em longo prazo a taxas de juros acima de 3% (a.a) mostrou-se consistente, porém o período de payback mesmo à taxa de juros 1% a.a foi elevada (6,54 anos) em condições de financiamento

    Novel molecularly imprinted impedimetric biosensor based on polypyrrole and decorated graphene oxide for the routine monitoring of Lysozyme

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    In this work, a novel molecularly imprinted polymer based on polypyrrole (PPy) and decorated graphene oxide (GO@Fe3O4) was developed for the sensitive detection of lysozyme (LYS). The synthesized material (MIPPy/GO@Fe3O4) was electrodeposited with LYS as a template on gold microelectrodes. Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) were used to confirm the adequate preparation of GO@Fe3O4, and the characterization of the resulting microsensors was carried out with the following analytical techniques: electrochemical impedance spectrometry (EIS), FT-IR analysis and scanning electron microscopy (SEM). An equivalent circuit was suggested to quantitatively analyse each component of the sensor system. EIS was also used for the determination of LYS in a wide linear range from 1 to 1 105 pg/mL, presenting good precision (RSD ≈ 10%, n = 5) and low limits of detection and quantification (LOD = 0.009 pg/mL and LOQ = 0.9 pg/mL, respectively). Meanwhile, the microsensor showed a high sensitivity, a good selectivity and reproducibility. The construction process was relatively simple, and provided a rapid and economical method for the routine monitoring of LYS. The microsensor was successfully applied for the detection of this protein in fresh chicken-egg white sample and commercial drug.Campus de Excelencia Internacional Andalucía Tech. Beca FPU18/05371 Proyecto de la Junta de Andalucía UMA18FEDERJA06

    Decrease in Bone Mass in Women After Liver Transplantation: Associated Factors

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    AbstractBackgroundIn the future, an increasing number of female liver transplant recipients will reach the climacteric with osteoporosis as a common complication. We evaluated the factors associated with decreased bone mass among women after liver transplantation.MethodsA prospective, cross-sectional study of 23 outpatient transplant recipients followed from February 2009 to March 2010 included women of age ≥35 years after liver transplantations ≥1 year prior. We recorded patient histories, liver enzyme levels, as well as bone mineral densities measured at the lumbar spine and femur. Statistical analysis used Fisher's exact test, simple odds ratio (OR), and Spearman's rank correlation coefficient.ResultsThe mean patient age was 52.5 ± 11 years with 30.4% premenopausal, and 69.6% perimenopausal or postmenopausal. Approximately 21% showed osteoporosis and 35%, a low bone mass. Postmenopausal women: OR 69.0 (95% CI 2.89–1647.18; P < .0001), aged ≥49 years: OR 13.33 (95% CI 1.78–100.15; P = .0123) and receiving a transplant after 44 years of age: OR 49.50 (95% CI 3.84–638.43; P < .0001) were associated with a lower bone mass. Having undergone transplantation for more than 5.8 years lowered the risk of bone mass change: OR 0.11 (95% CI 0.02–0.78; P = .0361). Clinical and laboratory variables, including corticosteroid use, were not associated with decreased bone mass.ConclusionUnderstanding the prevalence and factors associated with osteoporosis among female liver transplant recipients is important to enhance the strategies to diagnose and treat these women, seeking to improve their quality of life

    Modeling the major influencing factor on match running performance during the in-season phase in a Portuguese professional football team

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    The aim of this study was two-fold: (1) to analyze the influence of season phase (i.e., the start of the in-season and mid-in-season) on match running performance in a Portuguese professional football team; (2) to determine and model the main factor influencing match running performance during the in-season in this specific football team. Eighteen matches were collected by an 18 Hz global positioning system (GPS) from a professional Portuguese football team during the start of the in-season and mid-in-season. The match running performance was analyzed according to season phases, presenting significant differences in total distance (TD) (tlower bound = 4.71, p < 0.001; tupper bound = −2.22, p = 0.002), average speed (AvS) (tlower bound = 359.45, p < 0.001; tupper bound = −359.87, p < 0.001), and relative high speed running (rHSR) (tlower bound = 13.10, p < 0.001; tupper bound = −10.21, p < 0.001). The logistic regression showed TD (β = −1.59, z = −2.84, p = 0.005) and AvS (β = 2.68, z = −2.84, p = 0.007) as the major factors influencing match running performance during seasonal variation. Sprints and accelerations showed no significance for predicting match running performance during the season phases (β = −0.05 to 1.07, z = −0.95 to 1.07, p = 0.29 to 0.72). Current research confirms that lower and upper bounds should be used to quantify seasonal differences on match running performance. TD and AvS were described as the main factors influencing match running performance during the in-season phase. Thus, it is important to highlight the pace and volume of the game to maximize match running performance.This project was supported by the National Funds through FCT—Portuguese Foundation for Science and Technology (UIDB/DTP/04045/2020).info:eu-repo/semantics/publishedVersio

    Weekly training load across a standard microcycle in a sub-elite youth football academy: a comparison between starters and non-starters

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    Compensatory training sessions have been highlighted as useful strategies to solve the differential weekly training load between the players’ starting status. However, the influence of the players’ starting status is still understudied in sub-elite youth football. Thus, the aim of this study was to compare the weekly training load on a standard microcycle in starters and non-starters of a sub-elite youth football academy. The weekly training load of 60 young sub-elite football players was monitored during a 6-week period using an 18 Hz global positioning system (GPS), 1 Hz telemetry heart rate, rating of perceived exertion (RPE), and total quality recovery (TQR). The total distance (TD) covered presented a significant difference between starters and non-starters with a moderate effect (t = 2.38, D = 428.03 m, p = 0.018, d = 0.26). Training volume was higher in non-starters than in starter players (TDStarters = 5105.53   1684.22 vs. TDNon-starters = 5533.56   1549.26 m). Significant interactive effects were found between a player’s starting status, playing time, and session duration in overall training load variables for within (F = 140.46;  2 = 0.85; p < 0.001) and between-subjects (F = 11.63 to 160.70;  2 = 0.05 to 0.76; p < 0.001). The player’s starting status seems to only influence the training volume in sub-elite youth football, unless one considers the covariance of the playing time and session duration. Consequently, coaches should prioritize complementary training to equalize training volume and emphasize similar practice opportunities for non-starters. Future studies should evaluate the gap between training and match load, measuring the impact of recovery and compensatory sessions.This project was supported by the National Funds through the FCT—Portuguese Foundation for Science and Technology (project UIDB04045/2021).info:eu-repo/semantics/publishedVersio

    Medição da potência, força, velocidade e eficácia mecânica no Futebol: considerações teóricas

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    Power-force-velocity profiles in football can be assessed by Samozino’s formulas to determine theoretical maximal velocity (V0), theoretical horizontal force (F0), horizontal power (Pmax) and force-velocity (F-V) profile (i.e., the slope of the F-V relationship; Sfv), ratio of force (RFmax) and index of force application technique (DRF). Current critical review aims to explain the theoretical and methodological procedures for measuring power, force, velocity, and mechanical effectiveness in Football. In conclusion, Samozino’s method is sensitive, straightforward, and cost-effective for measuring F-V relationship and mechanical effectiveness in Football. Therefore, this methodological approach should be considered in field-based assessment and monitoring strategy of the football players. Future research should also include different competitive level such as elite, sub-elite and recreational for measuring power, force, velocity, and mechanical effectiveness in male, female, and youth football environments.Os perfis potência-força-velocidade no futebol podem ser avaliados pelas fórmulas de Samozino, de modo a determinar a velocidade máxima teórica (V0), a força máxima teórica (F0), a potencia máxima teórica (Pmax), o perfil força velocidade (F-V) (inclinação da relação F- V, Sfv), a razão de força (RFmax) e o índice da técnica de aplicação de força (DRF). A presente revisão crítica pretende esmiuçar os procedimentos teóricos e metodológicos para mensurar a potência, a força, a velocidade e a eficácia mecânica no Futebol. Concluiu-se que o método de Samozino é sensível, prático e económico para medir a relação F-V e a eficácia mecânica no Futebol. Assim, esta abordagem metodológica deve ser considerada nas estratégias de campo para a avaliação e monitorização de jogadores de futebol. As futuras investigações devem considerar igualmente os diferentes níveis competitivos, concretamente os contextos elite, subelite e amadores, aportando novas evidências para a mensuração da potência, força, velocidade e eficácia mecânica em contextos de futebol masculino, feminino e juvenil.info:eu-repo/semantics/publishedVersio

    Quantifying sub-elite youth football weekly training load and recovery variation

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    Monitoring the training load in football is an important strategy to improve athletic performance and an effective training periodization. The aim of this study was two-fold: (1) to quantify the weekly training load and recovery status variations performed by under-15, under-17 and under-19 sub-elite young football players; and (2) to analyze the influence of age, training day, weekly microcycle, training and playing position on the training load and recovery status. Twenty under-15, twenty under-17 and twenty under-19 players were monitored over a 2-week period during the first month of the 2019-2020 competitive season. Global positioning system technology (GPS) was used to collect external training loads: total distance covered, average speed, maximal running speed, relative high-speed running distance, high metabolic load distance, sprinting distance, dynamic stress load, accelerations and decelerations. Internal training load was monitored using ratings of perceived exertion (RPE) and session rating of perceived exertion (sRPE). Recovery status was obtained using the total quality recovery (TQR) scale. The results show an age-related influence for external training load (p <= 0.001; d = 0.29-0.86; moderate to strong effect), internal training load (p <= 0.001, d = 0.12-0.69; minimum to strong effect) and recovery status (p <= 0.001, d = 0.59; strong effect). The external training load presented differences between training days (p < 0.05, d = 0.26-0.95; moderate to strong effect). The playing position had a minimum effect on the weekly training load (p < 0.05; d = 0.06-0.18). The weekly microcycle had a moderate effect in the TD (p < 0.05, d = 0.39), RPE (p < 0.05; d = 0.35) and sRPE (p < 0.05, d = 0.35). Interaction effects were found between the four factors analyzed for deceleration (F = 2.819, p = 0.017) and between inter-day, inter-week and age for total covered distance (F = 8.342, p = 0.008). This study provided specific insights about sub-elite youth football training load and recovery status to monitor training environments and load variations. Future research should include a longer monitoring period to assess training load and recovery variations across different season phases.This research was supported by the Douro Higher Institute of Educational Sciences and the Portuguese Foundation for Science and Technology, I.P. (project UIDB04045/2021). Documentinfo:eu-repo/semantics/publishedVersio

    The Association between external training load, perceived exertion and total quality recovery in Sub-Elite youth football

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    Moderate to very large correlation between internal training load, external training load, and recovery status have been reported in elite youth football. However, little is known about subelite youth football training environments. Objective: The purpose of this study was to assess the association between training load and recovery status in young subelite football players. Methods: Twenty under-15, twenty under-17, and twenty under-19 players were monitored over a 6-week period during the first month of the 2019-2020 competitive season. The global positioning system technology (GPS) was used to collect external training load variables. The internal training load variables were monitored using the rating of perceived exertion (RPE) scale and session RPE (sRPE). The recovery status was assessed by the total quality recovery (TQR). A total of 18 training sessions and 324 observation cases were collected. Results: Small to moderate correlation between internal and external load was observed r( = -0.316 to 0.136, p < 0.05). Correlations between recovery status and external load were moderate for U15 (r = -0.326 to -0.240, p < 0.05), U17 (r = -0.316 to 0.136, p < 0.05) and U19 (r = -0.301 to 0.282, p < 0.05). The association between perceived exertion and external training load is only significant for U19 subelite football players. Conclusion: Current research suggested that subelite youth football players were more likely to have lower capacity to judge training exertion. Additionally, recovery status was positively correlated with acceleration and deceleration movements. This study provides a new overview about training load and recovery in subelite youth training environment. Future researche should examine the between- and within-individual nonlinearity across training load and recovery variations.This project was supported by the National Funds through FCT-Portuguese Foundation for Science and Technology (UIDB/DTP/04045/2020).info:eu-repo/semantics/publishedVersio
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