scholarly journals DESIGNING AN EXPERIMENT FOR EVALUATING SEATING POSITIONS IN PARALYMPIC ROWING

2020 ◽  
Vol 1 ◽  
pp. 2485-2494
Author(s):  
S. W. Eikevåg ◽  
A. Kvam ◽  
M. K. Bjølseth ◽  
J. F. Erichsen ◽  
M. Steinert

AbstractWhen designing high performance sports equipment for Paralympic athletes, there are many unknowns for the design engineer to consider. The design challenge is an optimisation task per individual athlete. However, modelling this optimisation is difficult due to the many variables. This article presents the design of an experiment for identifying and evaluating various seating positions in Paralympic rowing by using a rowing ergometer with a modified seat. Results indicate that changing seating position has a substantial impact on per-athlete rowing performance.

2020 ◽  
Vol 16 ◽  
Author(s):  
Luxia Zheng ◽  
Xiong Shen ◽  
Yingchun Wang ◽  
Jian Liang ◽  
Mingming Xu ◽  
...  

Background: Phospholipids are widely used in food and pharmaceutical industry as functional excipients. In spite of the many analytical methods reported, there are very limited reports concerning systematic research and comparison of phospholipid excipients. Objective: To present a comprehensive evaluation of commercial natural phospholipid excipients (CNPEs). Methods: Seventeen batches of CNPEs from five manufacturing enterprises, isolated either from soybean or egg yolk, were investigated. The content and composition of phospholipids, fatty acids and sterols as a whole were considered as the evaluative index of CNPEs. Eight kinds of phospholipids were determined by supercritical fluid chromatography (SFC), twenty-one kinds of fatty acids were determined by gas chromatography (GC) after boron trifluoride-methanol derivatization, and nine kinds of sterols were determined by high performance liquid chromatography (HPLC) after separation and derivatization of the unsaponifiable matter. Cluster analysis was employed for classification and identification of the CNPEs. Results: The results showed that each kind of CNPEs had its characteristic content and composition of phospholipids, fatty acids and sterols. Seventeen batches of samples were divided into eight groups in cluster analysis. CNPEs of the same type from different source (soybean or egg yolk) or enterprises presented different content and composition of phospholipids, fatty acids and sterols. Conclusion: Each type of CNPEs had its characteristic content and composition of phospholipid, fatty acid and sterol. The compositions of phospholipid, fatty acid and sterol as a whole can be applied as an indicator of the quality and characteristics for CNPEs.


Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1455
Author(s):  
David T. Bird ◽  
Nuggehalli M. Ravindra

The US Department of Defense (DoD) realizes the many uses of additive manufacturing (AM) as it has become a common fabrication technique for an extensive range of engineering components in several industrial sectors. 3D Printed (3DP) sensor technology offers high-performance features as a way to track individual warfighters on the battlefield, offering protection from threats such as weaponized toxins, bacteria or virus, with real-time monitoring of physiological events, advanced diagnostics, and connected feedback. Maximum protection of the warfighter gives a distinct advantage over adversaries by providing an enhanced awareness of situational threats on the battle field. There is a need to further explore aspects of AM such as higher printing resolution and efficiency, with faster print times and higher performance, sensitivity and optimized fabrication to ensure that soldiers are more safe and lethal to win our nation’s wars and come home safely. A review and comparison of various 3DP techniques for sensor fabrication is presented.


2012 ◽  
Vol 7 (2) ◽  
pp. 152-160 ◽  
Author(s):  
Amelia J. Carr ◽  
Gary J. Slater ◽  
Christopher J. Gore ◽  
Brian Dawson ◽  
Louise M. Burke

Purpose:The aim of this study was to determine the effect and reliability of acute and chronic sodium bicarbonate ingestion for 2000-m rowing ergometer performance (watts) and blood bicarbonate concentration [HCO3−].Methods:In a crossover study, 7 well-trained rowers performed paired 2000-m rowing ergometer trials under 3 double-blinded conditions: (1) 0.3 grams per kilogram of body mass (g/kg BM) acute bicarbonate; (2) 0.5 g/kg BM daily chronic bicarbonate for 3 d; and (3) calcium carbonate placebo, in semi-counterbalanced order. For 2000-m performance and [HCO3−], we examined differences in effects between conditions via pairwise comparisons, with differences interpreted in relation to the likelihood of exceeding smallest worthwhile change thresholds for each variable. We also calculated the within-subject variation (percent typical error).Results:There were only trivial differences in 2000-m performance between placebo (277 ± 60 W), acute bicarbonate (280 ± 65 W) and chronic bicarbonate (282 ± 65 W); however, [HCO3−] was substantially greater after acute bicarbonate, than with chronic loading and placebo. Typical error for 2000-m mean power was 2.1% (90% confidence interval 1.4 to 4.0%) for acute bicarbonate, 3.6% (2.5 to 7.0%) for chronic bicarbonate, and 1.6% (1.1 to 3.0%) for placebo. Postsupplementation [HCO3−] typical error was 7.3% (5.0 to 14.5%) for acute bicarbonate, 2.9% (2.0 to 5.7%) for chronic bicarbonate and 6.0% (1.4 to 11.9%) for placebo.Conclusion:Performance in 2000-m rowing ergometer trials may not substantially improve after acute or chronic bicarbonate loading. However, performances will be reliable with both acute and chronic bicarbonate loading protocols.


Robotica ◽  
1996 ◽  
Vol 14 (3) ◽  
pp. 321-327 ◽  
Author(s):  
R.E. Ellis ◽  
O.M. Ismaeil ◽  
M.G. Lipsett

SUMMARYA haptic interface is a computer-controlled mechanism designed to detect motion of a human operator without impeding that motion, and to feed back forces from a teleoperated robot or virtual environment. Design of such a device is not trivial, because of the many conflicting constraints the designer must face.As part of our research into haptics, we have developed a prototype planar mechanism. It has low apparent mass and damping, high structural stiffness, high force bandwidth, high force dynamic range, and an absence of mechanical singularities within its workspace. We present an analysis of the human-operator and mechanical constraints that apply to any such device, and propose methods for the evaluation of haptic interfaces. Our evaluation criteria are derived from the original task analysis, and are a first step towards a replicable methodology for comparing the performance of different devices.


2014 ◽  
Vol 981 ◽  
pp. 431-434
Author(s):  
Zhan Peng Jiang ◽  
Rui Xu ◽  
Chang Chun Dong ◽  
Lin Hai Cui

Network on Chip(NoC),a new proposed solution to solve global communication problem in complex System on Chip (SoC) design,has absorbed more and more researchers to do research in this area. Due to some distinct characteristics, NoC is different from both traditional off-chip network and traditional on-chip bus,and is facing with the huge design challenge. NoC router design is one of the most important issues in NoC system. The paper present a high-performance, low-latency two-stage pipelined router architecture suitable for NoC designs and providing a solution to irregular 2Dmesh topology for NoC. The key features of the proposed Mix Router are its suitability for 2Dmesh NoC topology and its capability of suorting both full-adaptive routing and deterministic routing algorithm.


2009 ◽  
pp. 389-420
Author(s):  
Brian Goodman ◽  
Maheshwar Inampudi ◽  
James Doran

In this chapter, we introduce five practices to help build scalable, resilient Web applications. In 2004, IBM launched its expertise location system, bringing together two legacy systems and transforming the employee’s ability to find and connect with their extensive network. This chapter reviews five of the many issues that challenge enterprise Web applications: resource contention, managing transactions, application resiliency, geographic diversity, and exception perception management. Using the IBM expertise location system as context, we will present five key methods that mitigate these risks, achieving high availability and high performance goals.


2014 ◽  
Vol 9 (1) ◽  
pp. 139-144 ◽  
Author(s):  
Ruth M. Hobson ◽  
Roger C. Harris ◽  
Dan Martin ◽  
Perry Smith ◽  
Ben Macklin ◽  
...  

The ability to buffer H+ could be vital to exercise performance, as high concentrations of H+ contribute to the development of fatigue.Purpose:The authors examined the effect of sodium bicarbonate (SB) supplementation on 2000-m rowing-ergometer performance.Methods:Twenty male rowers (age 23 ± 4 y, height 1.85 ± 0.08 m, mass 82.5 ± 8.9 kg, 2000-m personal-best time 409 ± 16 s) completed two 2000-m rowing-ergometer time trials, separated by 48 h. Participants were supplemented before exercise with 0.3 g/kg body mass of SB or a placebo (maltodextrin; PLA). The trials were conducted using a double-blinded, randomized, counterbalanced crossover study design. Time to complete the 2000-m and time taken for each 500-m split were recorded. Blood lactate, bicarbonate, pH, and base excess were determined preexercise, immediately postexercise, and 5 min postexercise. Performance data were analyzed using paired t tests, as well as magnitude-based inferences; hematological data were analyzed using a repeated-measures ANOVA.Results:Using paired t tests, there was no benefit of SB over PLA (P = .095). However, using magnitude-based inferences there was a likely beneficial effect of SB compared with PLA (PLA 412.0 ± 15.1 s, SB 410.7 ± 14.9 s). Furthermore, SB was 0.5 ± 1.2 s faster than PLA in the third 500 m (P = .035; possibly beneficial) and 1.1 ± 1.7 s faster in the fourth 500 m (P = .004; very likely beneficial). All hematological data were different between SB and PLA and were different from preexercise to postexercise.Conclusion:SB supplementation is likely to be beneficial to the performance of those competing in 2000-m rowing events, particularly in the second half of the event.


2016 ◽  
Vol 28 (4) ◽  
pp. 572-579 ◽  
Author(s):  
Hugo Maciejewski ◽  
Abderrahmane Rahmani ◽  
Frédéric Chorin ◽  
Julien Lardy ◽  
Caroline Giroux ◽  
...  

Purpose:The aim of the current study was to determine whether the anaerobic performance assessed by a modified Wingate test could account for the 1,500-m rowing ergometer performance in young competitive rowers.Methods:Fourteen national-level adolescent rowers performed on a rowing ergometer i) a 30-s allout exercise (i.e., modified Wingate test) and ii) a 1,500-m all-out exercise (i.e., rowing performance). For each of these two exercises, the mean power output was considered as the main performance criterion (PWIN and P1500, respectively).Results:PWIN was correlated to P1500 (r2 = .83, p < .0001, β = 100%). Furthermore, the estimated total muscle mass was correlated to PWIN and P1500 (r2 = .72 and r2 = .83, p < .0001, β = 100%, respectively). The allometric scaling also indicated that total muscle mass accounts 62% for the relationship between PWIN and P1500.Conclusion:Our results highlight the importance of considering the contribution of total muscle mass and anaerobic energy pathways to 1,500-m rowing performance in competitive adolescent rowers. Therefore, the modified Wingate test could be used by rowing coaches to potentially identify talented young rowers.


2012 ◽  
Vol 22 (4) ◽  
pp. 251-256 ◽  
Author(s):  
Hannah Bond ◽  
Lillian Morton ◽  
Andrea J. Braakhuis

Increased plasma nitrate concentrations from dietary sources of nitrate have proven to benefit exercise performance. Beetroot (BR) contains relatively high levels of nitrate (NO3−), which increases nitric oxide stores. This study investigated whether dietary nitrate supplementation, in the form of a BR beverage, would improve rowing performance during ergometer repetitions. In a randomized crossover design, 14 well-trained junior male rowers consumed 500 ml of either BR or placebo (PL) daily for 6 d. After supplementation, rowers completed 6 maximal 500-m ergometer repetitions and times were recorded. A 7-d washout period separated the 2 trials. Blood pressure, oxygen saturation, maximum heart rate, urine (specific gravity, pH, and nitrites), and lactates were collected for analysis at baseline and pre- and postperformance. Changes in the mean with 95% confidence limits were calculated. There was a likely benefit to average repetition time in the BR condition, compared with PL (0.4%, 95% confidence limits, ± 1.0%). In particular, Repetitions 4–6 showed an almost certain benefit in rowing time on BR (1.7%, 95% CL, ± 1.0%). The underlying mechanism for the observed results remains unknown, as differences observed in rowers’ physiological measures between the 2 conditions were unclear. Conclusively, nitrate supplementation in the form of BR juice resulted in improved maximal rowing-ergometer repetitions, particularly in the later stages of exercise.


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