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This article presents a procedure that allows to theoretically and preliminarily calculate the levels of pollutants produced by any type of alternative internal combustion engine in order to reduce the costs and resources that brings an experimental test for the same purpose. The main objective of this study is to present the calculation of the levels of carbon dioxide, nitrogen oxides, and particulate material with an aerodynamic diameter of 2.5 micrometers, based on the geometrical and operation parameters of alternative internal combustion engines (MCIA), which are used in aircrafts and land vehicles. First of all, some of the previous investigations that were performed are presented, which are taken as a starting point to calculate the polluting emissions. Subsequently, the development carried out to find the braking power is shown, which value provides an important contribution when finding the levels of pollutants. Then, the results obtained are shown, which are compared to experimental test results to determine the reliability of the methodology through an analysis of variance –ANOVA. Finally, conclusions are presented., En este artículo se presenta un procedimiento que permite calcular teórica y preliminarmente los niveles de agentes contaminantes producidos por cualquier tipo de motor de combustión interna alternativo, con el fin de reducir los costos y recursos que trae consigo una prueba experimental para el mismo propósito. El objetivo principal de este artículo es presentar el cálculo de los niveles de dióxido de carbono, óxidos de nitrógeno y material particulado con un diámetro aerodinámico de 2.5 micrómetros, a partir de los parámetros geométricos y de operación de motores de combustión interna alternativo (MCIA), los cuales son utilizados en aeronaves y vehículos terrestres. En primera instancia se presentan algunas de las investigaciones previas realizadas, las cuales se toman como punto de partida para calcular las emisiones contaminantes. Posteriormente se muestra el desarrollo llevado a cabo para encontrar la potencia de frenado, cuyo valor permite proporcionar un aporte importante al momento de hallar los niveles de contaminantes. Luego, se muestran los resultados obtenidos, los cuales son comparados con resultados de pruebas experimentales para determinar la confiabilidad de la metodología mediante un análisis ANOVA (ANalysis Of VAriance) y finalmente se presentan las respectivas conclusiones.

The present study aimed to investigate the relationship between the mechanical load during resistance exercise and the elicited physiological responses. Ten resistance-trained healthy male subjects performed 1 set of resistance exercise each at 55%, 70%, and 85% of 1 repetition maximum for as many repetitions as possible and in 4 training modes: 4-1-4-1 (4 s concentric, 1 s isometric, 4 s eccentric, and 1 s isometric successive actions), 2-1-2-1, 1-1-1-1, and explosive (maximum velocity concentric). Mean concentric power and total concentric work were determined. Oxygen uptake ((V) over dotO(2)) was measured during exercise and for 30 min post exercise. Total volume of consumed oxygen (O-2 consumed) and excess post-exercise oxygen consumption (EPOC) were calculated. Maximum blood lactate concentration (LAmax) was also determined. (V) over dotO(2) exhibited a linear dependency on mean concentric power. Mean concentric power did not have a detectable effect on EPOC and LAmax. An augmentation of total concentric work resulted in significant linear increase of O-2 consumed and EPOC. Total concentric work caused a significant increase in LAmax. In general, a higher mechanical load induced a larger physiological response. An increase in mean concentric power elicited higher aerobic energy turnover rates. However, a higher extent of total concentric work augments total energy cost covered by oxidative and (or) glycolytic pathways.

The purpose of this study was to demonstrate that elite football players with the same anaerobic threshold calculated from the lactate performance curve during a field level test may have substantially different values describing endurance performance capacity determined from spiroergometric laboratory tests. A group of 28 male elite football players underwent a field level test and a spiroergometric laboratory test. A subgroup of players with the same anaerobic threshold was selected, and the endurance performance capacity obtained from spiroergometric measurements during treadmill level tests were compared descriptively within this subgroup. Among the three players with the same anaerobic threshold, test duration for the treadmill level test and consequently also the maximal lactate value achieved during the test varied substantially. The tests were aborted after 5 min at 4.4, 4.8 and 4.0 m·s-1 for players 1, 2 and 3, respectively. VO2-values at V4 were 87 %, 75 % and 96 % of their personal VO2-peak, respectively. Maximum lactate concentrations were 8.8, 9.2 and 5.3 mmol·L-1, respectively. Peak relative VO2 values were 55.0, 61.6 and 59.7 ml·min-1·kg-1, respectively. The result of this study clearly show that conventional field level tests yield insufficient information on underlying physiological and metabolic mechanisms of endurance performance capacity. Taking result of spiroergometric tests into account is critical for designing and evaluating player-specific training programs aimed at optimizing each player’s performance.