Evaluation of New, Sputtered Carbon SPME Fibers with a Multi-Functional Group Test Mixture

We report the first fabrication of sputtered carbon, solid-phase microextraction (SPME) fibers. These fibers have competitive extraction capabilities compared with the commercial carbon wide range (CWR) SPME fiber. This report also includes a demonstration of a newly developed SPME test mix that includes 15 different compounds with a wide range of functional groups and chemical properties. The fiber fabrication process involves sputtering carbon onto fused silica fibers, and the effects of throw distance on the morphology of the carbon coatings were studied. Four different carbon coating thicknesses were evaluated, with PDMS added as a stationary phase. These fibers were characterized with multiple analytical techniques, including scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), water contact angle (WCA) goniometry, as well as headspace (HS) and direct immersion (DI)–SPME–GC–MS. The best (11.5 µm) sputtered carbon SPME fibers, with and without PDMS, were evaluated using the new evaluation mix and compared with the commercial CWR fiber and a previously sputtered/developed silicon fiber. The new probe mix helped elucidate differences among the fibers, which would have been missed by current commercial test mixes. The sputtered carbon SPME fibers showed similar functional group selectivity as commercial CWR fibers. However, the sputtered carbon fibers showed higher responses per volume compared with the commercial CWR fiber, indicating the porous morphology of the sputtered carbon has the ability to overcome large phase thickness/volume discrepancies and increase the relative recovery for various compounds.

Study on the Parameter Equation of Coal and Gas Outburst Hole

Studying the parameters of a coal and gas hole (CGOH), such as the hole shape, hole size and volume, coal quantity of CGOH, coal throw distance, calculated hole density, and gas pressure, is helpful in revealing the coal and gas outburst mechanism. In this study, we found that there were close mathematical relationships between these parameters. A nonlinear composite function relationship (CGOH parameter equation) was observed between the coal quantity, CGOH volume, and throw distance. The correctness of these relationships was verified using the Origin software. The stagnation point and inflection point of the parameter curve were obtained through the derivation of the parameter equation, and the transformation path from coal and gas outburst to coal and gas extrusion or dumping was clarified. At the same time, the equations of gas pressure, coal quantity, and throw distance are derived.

Novel Alumina Compounds with Niobia, Silica and Magnesia for Ballistic Armor

Compounds of alumina APC-2011 SG with niobia, silica and magnesia were sintered at 1400°C/3h, in order to evaluate their ballistic performance. The content of niobia (Nb2O5) was 4.0 to 8.0 wt.%; silica (SiO2) was 0.8 wt.%; and magnesia (MgO) at 0.15 wt.%. Sintered samples were characterized by hardness, densification and energy absorption at impact. Ballistic tests were performed by ceramic discs firmly glued to steel plates and then subjecting the target to impact using 7.62 mm projectile shot from a rifle with a throw distance of 5 m. The energy absorbed by the disintegration of the ceramic discs was estimated by the residual velocity. The fracture surfaces of the samples were observed by scanning electron microscopy. It was verified for the first that the addition of high amounts of Nb2O5 to the alumina with the presence of SiO2 and MgO increases the presence of vitreous phase in the contours of alumina grains and improved the properties of the material for use in ballistic protection.

Pedagogía no lineal en balonmano. Defensa zonal de una y dos líneas en partidos reducidos (Non-linear pedagogy in handball. One and two lines zone defence in small-sided games)

La pedagogía no lineal presenta diferencias importantes respecto a los modelos de enseñanza tradicionalmente empleados en balonmano. La ausencia de investigaciones sobre el proceso de enseñanza-aprendizaje en balonmano desde la pedagogía no lineal motivó el presente trabajo. El objetivo fue conocer la influencia ejercida por dos constreñimientos introducidos en una tarea: defensa zonal de una línea (LI1) y defensa zonal de dos líneas con defensor avanzado (LI2), en los comportamientos, ofensivos y defensivos, realizados por jugadores de balonmano. Estos constreñimientos, representativos de los sistemas defensivos más utilizados en balonmano, se aplicaron en la disputa de 16 partidos reducidos, durante las ocho sesiones en las que se desarrolló el estudio. Se utilizó un diseño observacional puntual/nomomético/multidimendional para registrar los comportamientos de 14 jugadores (M=14.6 años y SD=0.4) de categoría cadete masculino, que se dividieron en dos grupos para la disputa de los partidos. El análisis de coordenadas polares permitió conocer la influencia ejercida por ambos constreñimientos a nivel general, analizando los comportamientos de ambos equipos conjuntamente y, también, de manera específica para cada equipo. Así, se encontraron relaciones significativas de activación mutua entre: (1) LI1 y fijación impar, lanzamiento en penetración, lanzamiento a distancia, bloqueo, cambio de oponente, ayudas y contrabloqueo; y (2) entre LI2 y desmarques, deslizamiento e interceptación. Conocer la influencia ejercida por los constreñimientos aplicados en las tareas (comportamientos que facilitan e inhiben) es clave en la aplicación de la pedagogía no lineal, de esta manera se podrán seleccionar aquellos que ayuden a conseguir los objetivos propuestos. Abstract. Non-linear pedagogy presents important differences regarding the teaching approaches traditionally used in handball. The absence of research that addresses the teaching-learning process in handball from nonlinear pedagogy motivated the present work. The objective was to analyse the influence of certain task constraints: zonal defense of one line (LI1) and zonal defense of two lines with advanced defender (LI2), in the behaviour patterns, offensive and defensive ones, performed by handball players. These constraints, representative of the most used defensive handball systems, were applied in 16 small-sided games, during the eight sessions in which the study was developed. A nomothetic/punctual/monitoring observational design was used to register the behaviours performed by 14 players (M = 14.6 years and SD = 0.4), members of a team that competes in the male cadet category, who were divided into two groups for the matches. The analysis of polar coordinates allowed to know the influence exerted by both constraints at a general level, analyzing jointly the behaviors of both teams and, also, specifically for each team. Thus, significant relationships of mutual activation were found between: (1) LI1 and odd fixation, penetration throw, distance throw, block, opponent change, assist and counter block; and (2) between LI2 and uncheck, slip and intercept. Knowing the influence exerted by the task constraints (behaviors that facilitate and inhibit) is key in the application of non-linear pedagogy, in this way those that help to achieve the proposed objectives can be selected.

Methods for Regulating and Monitoring Resistance Training

Individualisation can improve resistance training prescription. This is accomplished via monitoring or autoregulating training. Autoregulation adjusts variables at an individualised pace per performance, readiness, or recovery. Many autoregulation and monitoring methods exist; therefore, this review’s objective was to examine approaches intended to optimise adaptation. Up to July 2019, PubMed, Medline, SPORTDiscus, Scopus and CINAHL were searched. Only studies on methods of athlete monitoring useful for resistance-training regulation, or autoregulated training methods were included. Eleven monitoring and regulation themes emerged across 90 studies. Some physiological, performance, and perceptual measures correlated strongly (r ≥ 0.68) with resistance training performance. Testosterone, cortisol, catecholamines, cell-free DNA, jump height, throwing distance, barbell velocity, isometric and dynamic peak force, maximal voluntary isometric contractions, and sessional, repetitions in reserve-(RIR) based, and post-set Borg-scale ratings of perceived exertion (RPE) were strongly associated with training performance, respectively. Despite strong correlations, many physiological and performance methods are logistically restrictive or limited to lab-settings, such as blood markers, electromyography or kinetic measurements. Some practical performance tests such as jump height or throw distance may be useful, low-risk stand-ins for maximal strength tests. Performance-based individualisation of load progression, flexible training configurations, and intensity and volume modifications based on velocity and RIR-based RPE scores are practical, reliable and show preliminary utility for enhancing performance.

Angular Kinematics and Physical Fitness Analysis of Tall height and Short Height Javelin Throwers- A Case Study of The Islamia University of Bahawalpur, Pakistan

This study was designed to compare the physical fitness and angular position of the university level javelin throwers. Eight tall height and (n = 08) short height javelin throwers were selected for data collection. A handgrip dynamometer, stadiometer, and weight balance were used for the measurements of physical fitness. Two video cameras a Kinovea software was utilized for video analysis of the Javelin throws. The selected variables were stature, body mass, standing broad jump, maximum bench press handgrip strength, the javelin throw distance. The angle of knee joint, elbow joints, and stride length was selected variables while performing the javelin throw. An independent t-test was applied to find mean difference among tall and short height javelin thrower. The result showed the distance of javelin throw, handgrip strength, maximum bench press, vertical jump, and standing broad jump of tall height throwers were significantly higher than short height javelin throwers. On the other hand, the tall height throwers were also significantly higher in extension of right elbow, right knee, and stride length than the short height at the time of the javelin release from hand. It was concluded the longer arms, body mass, and angular kinematics of javelin throwers are associated with the better performance. It is suggested the physical fitness would be include in the selection of javelin throw and angular movement of the right knee and elbow focused on training of javelin thrower.

Pedestrian Throw Distance Prediction from Vehicle Damage Intensity

One of the main points to be addressed when analysing vehicle-pedestrian collisions is the vehicle impact speed. If the traffic accident is not recorded on camera, and there are no skid marks nor tachograph in the vehicle, the parameter is determined on the basis of empirical models. All empirical models for ascertaining vehicle speed are based on the pedestrian throw distance, which is not always known because of an unidentified vehicle-pedestrian collision point or the final rest position of the pedestrian after collision. This paper shows a description of a vehicle damage recorded in an ordinal scale and determines the pedestrian throw distance prediction model from the vehicle damage established in such a way. If the accident scene is documented by photographs, the damage can be classified, and by applying a validated model, the pedestrian throw distance envisaged. Then, by applying an empirical model, one can determine the speed of the vehicle at the time of collision with a pedestrian. Two databases were formed during the research. The first is based on real-life traffic accidents (expert witnessing of the professors from the Faculty of Technical Sciences). The second is based on traffic accident simulations as part of PC Crash software package.

Attaching mass to the upper arm can increase throw distance in a modified javelin throw

Purpose: The effectiveness of the whip-like coordination in throwing might be influenced by the inertial properties of the athlete’s arm. This preliminary study investigated the acute effect of attaching mass to the upper arm on the distance achieved in a modified javelin throw. The aim was to identify the optimum upper arm mass that maximizes throw distance. Methods: Three well-trained adult male athletes performed maximum-effort throws with an 800-g javelin training ball. A wide range of masses (0–1.5 kg) were attached to the upper arm and a 2D video analysis was used to obtain measures of the projection variables for each attached mass. Results: All three athletes showed an effect of attached arm mass on throw distance, and with the optimum mass the athlete’s throw distance was increased by 2.2 m, 1.2 m, and 0 m (7%, 4%, and 0%) respectively. The optimum mass was specific to the athlete (0.6 kg, 0.2 kg, and 0 kg) and changes in throw distance were mostly due to changes in release velocity rather than changes in release angle or release height. The experimental results were broadly similar to those obtained using a simple 2D mathematical model of throwing. Conclusions: These results indicate that some javelin throwers might see an increase in throwing performance when a mass is attached to their upper arm. However, the relationship between upper arm mass and throwing performance should be investigated further with studies on more athletes, projectiles of different mass, and other throwing events.

Assessment of throwing arm biomechanics with a motusBASEBALLTM pitching sleeve during long-toss throws and pitching in college baseball pitchers

In baseball, long-toss throws are commonly used in return-to-throw programs and for general conditioning; however, the majority of these programs are based on conventional wisdom. Few studies have examined the biomechanics of long-toss throwing and the impact of throw distance. The purpose of this study was to determine if significant differences exist among commonly-used sub-maximal distance long-toss throws and mound pitching. Nineteen college baseball pitchers (19 ± 1.3 years; 88.3 ± 8.4 kg; and 73.9 ± 18.6 cm) wore a motusBASEBALL™ sleeve and sensor which measured peak elbow varus torque (VT), peak forearm angular velocity (Vmax), and peak arm-cocking angle (ACA). Each player completed five long-toss throws at distances of 27 m, 37 m, 46 m, 55 m and five pitches from a mound at regulation (18.4 m). There were no significant differences among throwing conditions for both VT and Vmax (p<0.05). For ACA, there was a significant increase (approximately 12°) as the long-toss distance increased. Coaches and trainers should be aware that sub-maximal distance long-toss throws (27 - 55 m+) generate high-magnitude throwing arm biomechanics (kinetics, velocities, range of motion) that approach or even exceed those generated during pitching; precaution needs to be used when implementing long-tosses into throwing and rehabilitation programs.