12,908 research outputs found

    Secondary zinc-oxygen cell for spacecraft applications Quarterly report, 23 Sep. - 23 Dec. 1967

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    Cycling performance of secondary zinc oxygen cell for spacecraf

    Separator for alkaline batteries

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    Separator compositions have been tested as components of three-plate silver-zinc oxide cells in a standard cycling test. Six materials meet imposed requirements, giving cycling performance superior to cellophane

    Spacecraft cell testing program Monthly progress report

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    Test data printout tables for cycling performance of Ag Cd, Ag Zn, Ni Cd, Pb Ca, and lead-acid cell

    The Effects of Mild Dehydration on Cycling Performance in the Heat

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    Abstract Introduction: Hypohydration exceeding 2% of body mass (bm), affected by heat and thirst level, leads to decreased athletic performance. Both physiological and psychological factors of dehydration have an impact on an athlete’s perceived performance. However, it is unclear whether the effects of psychological, physiological, or both have a negative impact on athletic performance caused by mild hypohydration. Purpose: The purpose of this study was to determine if mild hypohydration affects exercise performance in trained cyclists while blinding their hydration state. Methodology: Eleven competitive male cyclists participated in two blinded experimental trials, hypohydrated and euhydrated states by intra-venous infusions. The experimental criterium simulation test includes cycling through 3 sets of 20-minute steady state followed by a 5km race. Results: During the 5km time trial, the hypohydrated trial (39.0±0.5°C) resulted in significantly higher core temperatures compared to the euhydrated trial (38.5±0.2°C; P\u3c0.05). Cycling speed was significantly faster in the euhydrated vs. the hypohydrated trial (27.3±0.1 vs. 26.2±0.7 km×h-1; P\u3c0.05) due to greater cycling power output (304±6 vs. 286±10 W; P\u3c0.05). Conclusion: Overall, the study found that mild hypohydration led to impairment in exercise performance in the heat compared to euhydration, when subjects were unaware of their hydration state. These responses might have been a response of great heat strain and/or cardiovascular impairment

    The Effects of Music Genre on Cycling Performance and Perceived Exertion

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    Many people claim that music enhances their exercise experience. To our knowledge, no studies have analyzed the effect of music genre on exercise performance and perceived effort. Purpose: The purpose of this study was to analyze the effect of music genre on effort as well as perceived exertion while exercising. Methods: Eighteen untrained individuals, age 18-22, participated in this study. Participants performed two 25-minute exercise trials on a Monark bicycle ergometer. Participants were randomized to a music genre (either hip-hop, country or classical) and to condition (music or no music). Rating of perceived exertion (RPE), heart rate (HR), and resistance were recorded for the first ten minutes, while the same three measures and total calories burned were recorded for the final fifteen. Results: No significant difference was found in RPE between music and no music (p=0.477). The results of the Tukey post-hoc showed a significant increase in caloric expenditure between country music and hip-hop music (p=.008). There were no differences in RPE (F2,17=1.45, p=0.265) and music preference (F2,17=3.21, p=0.069) across genre. Conclusion: Based on these results, exercise performance and perceived effort were similar with or without music. When examining the effects of music genre, listening to country music increased caloric expenditure when compared to hip-hop music

    The effect of caffeine mouth rinse on self-paced cycling performance

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    The aim of the study was to determine whether caffeine mouth rinse would improve 30 min self-paced cycling trial. Twelve healthy active males (age 20.5±0.7 years, mass 87.4±18.3 kg) volunteered for the study. They attended the laboratory on 3 separate occasions performing a 30 min self-paced cycling trial. On one occasion water was given as a mouth rinse for 5 s (PLA), on another occasion a 6.4% maltodextrin (CHO) solution was given for 5 s and finally a caffeine solution (containing 32 mg of caffeine dissolved in 125 ml water; CAF) was given for 5 s. Distance cycled, heart rate, ratings of perceived exertion, cadence, speed and power output were recorded throughout all trials. Distance cycled during the CAF mouth rinse trial (16.2±2.8 km) was significantly greater compared to PLA trial (14.9±2.6 km). There was no difference between CHO and CAF trials (P=0.89). Cadence, power and velocity were significantly greater during the CAF trial compared to both PLA and CHO (P0.05). Caffeine mouth rinse improves 30 min cycling performance by allowing the participant to increase cadence, power and velocity without a concurrent increase in perceived exertion and heart rate

    Rechargeable ambient temperature lithium cells

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    The cycling performance of a secondary lithium cell with a 2-methyl THF lithium hectofluorarsenate electrolyte is discussed. Stripping efficiency, dendritization, passivation on standing, and discharge efficiency are considered

    The effect of different post-exercise beverages with food on ad libitum fluid recovery, nutrient provision, and subsequent athletic performance

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    This study investigated the effect of consuming either water or a carbohydrate (CHO)-electrolyte sports beverage (‘Sports Drink’) ad libitum with food during a 4 h post-exercise recovery period on fluid restoration, nutrient provision and subsequent endurance cycling performance. On two occasions, 16 endurance-trained cyclists; 8 male [M] (age: 31 ± 9 y; VO2max: 54 ± 6 mL·kg−1·min−1) and 8 female [F] (age: 33 ± 8 y; VO2max: 50 ± 7 mL·kg−1·min−1); lost 2.3 ± 0.3% and 1.6 ± 0.3% of their body mass (BM), respectively during 1 h of fixed-intensity cycling. Participants then had ad libitum access to either Water or Sports Drink and food for the first 195 min of a 4 h recovery period. At the conclusion of the recovery period, participants completed a cycling performance test consisting of a 45 min fixed-intensity pre-load and an incremental test to volitional exhaustion (peak power output, PPO). Beverage intake; total water/nutrient intake; and indicators of fluid recovery (BM, urine output, plasma osmolality [POSM]) were assessed periodically throughout trials. Participants returned to a similar state of net positive fluid balance prior to recommencing exercise, regardless of the beverage provided (Water: +0.4 ± 0.5 L; Sports Drink: +0.3 ± 0.3 L, p = 0.529). While Sports Drink increased post-exercise energy (M: +1.8 ± 1.0 MJ; F: +1.3 ± 0.5 MJ) and CHO (M: +114 ± 31 g; F: +84 ± 25 g) intake (i.e. total from food and beverage) (p's < 0.001), this did not improve subsequent endurance cycling performance (Water: 337 ± 40 W [M] and 252 ± 50 W [F]; Sports Drink: 340 ± 40 W [M] and 258 ± 47 W [F], p = 0.242). Recovery beverage recommendations should consider the post-exercise environment (i.e. the availability of food), an individual's tolerance for food and fluid pre−/post-exercise, the immediate requirements for refuelling (i.e. CHO demands of the activity) and the athlete's overall dietary goals.Full Tex

    Sprint cycling performance and asymmetry

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    The purpose of this study was to examine the asymmetries in cyclist’s lower limbs strength and in the pedalling kinematics during a seated sprinting test and to identify the relationships between asymmetries and maximal cycling power. 16 competitive road cyclists (20.6±3.7 yrs., 181.5±5.0 cm, 74.8±7.0 kg) performed 10 Sec isokinetic maximum power test with cadence 120 RPM. The asymmetry of kinematic patterns of cyclist’s upper and lower body during pedalling was registered. Separately isokinetic peak torque (PT) of main lover limbs joint were measured at angular speeds 60, 180 and 240/s. The differences in kinematic patterns and isokinetic PT values between two limbs were analysed for descriptive and inferential statistics (relative share in %, correlations and regression between asymmetry values and cycling power). Conclusion: The highest asymmetries were found in cyclist’s upper body kinematics and at the same time the most symmetrical were knee extensors strength values, but both parameters were negatively and significantly correlated with the performance of sprint cycling. By combining the leg extensors muscular strength with asymmetry of knee extensors strength and trunk kinematics the explanatory power of multiple regressions increased markedly from 0.68 to 0.92

    Cycling Performance of the Iron-Chromium Redox Energy Storage System

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    Extended charge-discharge cycling of this electrochemical storage system at 65 C was performed on 14.5 sq cm single cells and a four cell, 867 sq cm bipolar stack. Both the anolyte and catholyte reactant fluids contained 1 molar concentrations of iron and chromium chlorides in hydrochloric acid and were separated by a low-selectivity, cation-exchange membrane. The effect of cycling on the chromium electrode and the cation-exchange membrane was determined. Bismuth and bismuth-lead catalyzed chromium electrodes and a radiation-grafted polyethylene membrane were evaluated by cycling between 5 and 85 percent state-of-charge at 80 mA/sq cm and by periodic charge-discharge polarization measurements to 140 mA/sq cm. Gradual performance losses were observed during cycling but were recoverable by completely discharging the system. Good scale-up to the 867 sq cm stack was achieved. The only difference appeared to be an unexplained resistive-type loss which resulted in a 75 percent W-hr efficiency (at 80 mA/sq cm versus 81 percent for the 14.5 sq cm cell). A new rebalance cell was developed to maintain reactant ionic balance. The cell successfully reduced ferric ions in the iron reactant stream to ferrous ions while chloride ions were oxidized to chlorine gas
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