reaction time
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2022 ◽  
Vol 28 (1) ◽  
pp. 14-16
Wei Zong

ABSTRACT Introduction: Brief introduction: Taekwondo is a sport that integrates explosive power and reaction speed. The reaction speed of the athletes has a direct bearing on the result of the competition. Objective: To improve the reaction time effect of athletes. Methods: Forty-one Taekwondo team athletes were selected as the research subjects. Then, the training methods were introduced, and special technology using an emg tester and a synchronous camera system was implemented to analyze the earliest emg signals and the moment of the hit, the time from signal emergence to the emg reaction for reaction time, and from signal emergence to hit for the total time. Results: The average score of the 41 athletes before the test was 0.282673,with standard deviation of 0.0377349 and standard error of 0.0058932. The average score, standard deviation, and standard error of the 41 athletes after small training were 0.28217, 0.037744 and 0.005895. Conclusions: From the test results of the three training modes, the small training mode had a significant impact on the reaction time of Taekwondo athletes, while the medium and large training modes did not have significant effects. The results show that a small amount of training is best and plays a significant role in improving the reaction of an athlete. Level of evidence II; Therapeutic studies - investigation of treatment results.

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 656
Wei-Sheng Chen ◽  
Chih-Yuan Hsiao ◽  
Cheng-Han Lee

Electronic products are ever growing in popularity, and tantalum capacitors are heavily used in small electronic products. Spent epoxy-coated solid electrolyte tantalum capacitors, containing about 22 wt.% of tantalum and 8 wt.% of manganese, were treated with selective leaching by hydrochloric acid and chlorination after removing the epoxy resin, and the products converted, respectively, to Mn(OH)2 and TaCl5. The effects of acid type, acid concentration, liquid–solid ratio, and reaction time were investigated to dissolve the manganese. The optimal selective leaching conditions were determined as 3 mol/L of HCl, 40 mL/g at 25 °C for 32 min. Next, residues of selective leaching after washing and drying were heated with ferrous chloride to convert to pure TaCl5. Mixing 48 wt.% of chloride and 52 wt.% of residues for a total of 5 g was conducted to complete the chlorination process in the tube furnace at 450 °C for 3 h. A total of 2.35 g of Ta was collected and the recovery of Ta achieved 94%. Finally, Mn(OH)2 and TaCl5 were separated and purified as the products.

2022 ◽  
Ethan Michael McCormick ◽  
Rogier Kievit

Most prior research in the neural and behavioral sciences has been focused on characterizing averages in cognition, brain characteristics, or behavior, and attempting to predict differences in these averages among individuals. However, this overwhelming focus on mean levels may leave us with an incomplete picture of what drives individual differences in behavioral phenotypes by ignoring the variability of behavior around an individual’s mean. In particular, better white matter (WM) structural microstructure has been hypothesized to support consistent behavioral performance by decreasing gaussian noise in signal transfer. In contrast, lower indices of white matter microstructure have been associated with greater within-subject variance in the ability to deploy performance-related resources, especially in clinical samples. We tested this ‘neural noise’ hypothesis in a large adult lifespan cohort (Cam-CAN) with over 2500 individuals in a (2681 behavioral sessions with 708 scans in adults aged 18–102) using measures of WM tract microstructure to predict mean levels and variability in reaction time performance on a simple behavioral task using a dynamic structural equation model (DSEM). We found broad support for neural noise hypothesis, such that lower WM microstructure predicted individual differences in separable components of behavioral performance estimated using DSEM, including slower mean responses and increased variability. These effects were robust when including age in the model, suggesting consistent effects of WM microstructure across the adult lifespan above and beyond concurrent effects of ageing. Crucially, these results demonstrate the utility of DSEM for modeling and predicting behavioral variability directly, and the promise of studying variability for understanding cognitive processes.

2022 ◽  
Lidwien C.E. Veugen ◽  
A. John Van Opstal ◽  
Marc M. van Wanrooij

We tested whether joint spectrotemporal sensitivity follows from spectrotemporal separability for normal-hearing conditions and for impaired-hearing simulations. In a manual reaction-time task, normal-hearing listeners had to detect the onset of a ripple (with density between 0-8 cycles/octave and a fixed modulation depth of 50%), that moved up or down the log-frequency axis at constant velocity (between 0-64 Hz), in an otherwise-unmodulated broadband white-noise. Spectral and temporal modulations elicited band-pass filtered sensitivity characteristics, with fastest detection rates around 1 cycle/oct and 32 Hz for normal-hearing conditions. These results closely resemble data from other studies that typically used the modulation-depth threshold as a sensitivity measure for spectral-temporal modulations. To simulate hearing-impairment, stimuli were processed with a 6-channel cochlear-implant vocoder, and a hearing-aid simulation that introduced spectral smearing and low-pass filtering. Reaction times were always much slower compared to normal hearing, especially for the highest spectral densities. Binaural performance was predicted well by the benchmark race model of statistical facilitation of independent monaural channels. For the impaired-hearing simulations this implied a "best-of-both-worlds" principle in which the listeners relied on the hearing-aid ear to detect spectral modulations, and on the cochlear-implant ear for temporal-modulation detection. Although singular-value decomposition indicated that the joint spectrotemporal sensitivity matrix could be largely reconstructed from independent temporal and spectral sensitivity functions, in line with time-spectrum separability, a significant inseparable spectral-temporal interaction was present in all hearing conditions. These results imply that the reaction-time task yields a solid and effective objective measure of acoustic spectrotemporal modulation sensitivity, which may also be applicable to hearing-impaired individuals.

2022 ◽  
Virginia A. Marchman ◽  
Melanie Ashland ◽  
Elizabeth C. Loi ◽  
Kat Adams Shannon ◽  
Mónica Munévar ◽  

Associations between children’s early language processing efficiency and later language, literacy, and non-verbal outcomes shed light on the extent to which early information processing skills support later learning across domains. Examining whether the strengths of associations are similar in typically developing and at risk populations provides an additional lens into the varying routes to learning that children take across development. We compared patterns of associations between early language processing efficiency (accuracy and reaction time) in the looking-while-listening (LWL) task and school-relevant skills in children born full-term (FT) and preterm (PT). Participants (n=94, 49 FT, 45 PT) were assessed in the LWL task at 18 months (corrected for degree of prematurity in PT group) and on standardized tests of expressive language, pre-literacy (print knowledge and phonological awareness), and non-verbal IQ at 4 ½ years. Early language processing efficiency was associated with later language and pre-literacy outcomes (r2 change ranged from 19.8 to 7.1, p < 0.01) to a similar extent in PT and FT children, controlling for age at test and SES, suggesting similar mechanisms of learning in these domains for PT and FT children. However, birth group moderated the association between reaction time and non-verbal IQ (r2 change 4.5, p < 0.05), such that an association was found in the PT but not the FT group. This finding suggests that information processing skills reflected in efficiency of real-time language processing may be recruited to support learning in a broader range of domains in the PT compared to the FT group.

Ihsan Ahmed

Abstract We report the synthesis of interconnected ZnO nano structures through the addition of polyvinyl pyrrolidone (PVP) in a growth medium consisting of ZnCl2 and NaOH at a temperature of 70 0C with a reaction time of 24 hrs. The formation of interconnected ZnO is evaluated in accordance with the reaction time and reaction temperature used for the synthesis, and samples were characterized by powder X-ray diffraction, Fourier transform infra- red (FTIR) spectroscopy, Brunauer-Emmett-Teller(BET) analysis, Field emission scanning electron microscopy (FESEM), Photoluminescence (PL) and Electrochemical methods. BET studies show the mesoporous nature of ZnO grown with the addition of PVP in the growth medium. Interconnected ZnO nanostructures exhibit efficient visible light driven photo catalytic degradation of methylene blue (MB) attributed to interconnected morphology of ZnO. Electro chemical studies have shown that the interconnected ZnO nanostructures give higher order specific capacitance.

2022 ◽  
Vol 15 ◽  
Kevin J. Norman ◽  
Julia Bateh ◽  
Priscilla Maccario ◽  
Christina Cho ◽  
Keaven Caro ◽  

Top-down attention is a dynamic cognitive process that facilitates the detection of the task-relevant stimuli from our complex sensory environment. A neural mechanism capable of deployment under specific task-demand conditions would be crucial to efficiently control attentional processes and improve promote goal-directed attention performance during fluctuating attentional demand. Previous studies have shown that frontal top-down neurons projecting from the anterior cingulate area (ACA) to the visual cortex (VIS; ACAVIS) are required for visual attentional behavior during the 5-choice serial reaction time task (5CSRTT) in mice. However, it is unknown whether the contribution of these projecting neurons is dependent on the extent of task demand. Here, we first examined how behavior outcomes depend on the number of locations for mice to pay attention and touch for successful performance, and found that the 2-choice serial reaction time task (2CSRTT) is less task demanding than the 5CSRTT. We then employed optogenetics to demonstrate that suppression ACAVIS projections immediately before stimulus presentation has no effect during the 2CSRTT in contrast to the impaired performance during the 5CSRTT. These results suggest that ACAVIS projections are necessary when task demand is high, but once a task demand is lowered, ACAVIS neuron activity becomes dispensable to adjust attentional performance. These findings support a model that the frontal-sensory ACAVIS projection regulates visual attention behavior during specific high task demand conditions, pointing to a flexible circuit-based mechanism for promoting attentional behavior.

Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 206
Yicheng Wang ◽  
Yingkun Wang ◽  
Xi Lu ◽  
Wenquan Sun ◽  
Yanhua Xu ◽  

An Mn/[email protected] mud (RM) catalyst was prepared from RM via a doping–calcination method. Scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy were used to characterize the surface morphology, crystal morphology, and elemental composition of the Mn/[email protected] catalyst, respectively. In addition, preparation and catalytic ozonation conditions were optimized, and the mechanism of catalytic ozonation was discussed. Lastly, a fuzzy analytic hierarchy process (FAHP) was adopted to evaluate the degradation of coal chemical biochemical tail water. The best preparation conditions for the Mn/[email protected] catalyst were found to be as follows: (1) active component loading of 3%, (2) Mn/Ce doping ratio of 2:1, (3) calcination temperature of 550 °C, (4) calcination time of 240 min, and (5) fly ash floating bead doping of 10%. The chemical oxygen demand (COD) removal rate was 76.58% under this preparation condition. The characterization results suggested that the pore structure of the optimized Mn/[email protected] catalyst was significantly improved. Mn and Ce were successfully loaded on the catalyst in the form of MnO2 and CeO2. The best operating conditions in the study were as follows: (1) reaction time of 80 min, (2) initial pH of 9, (3) ozone dosage of 2.0 g/h, (4) catalyst dosage of 62.5 g/L, and (5) COD removal rate of 84.96%. Mechanism analysis results showed that hydroxyl radicals (•OH) played a leading role in degrading organics in the biochemical tail water, and adsorption of RM and direct oxidation of ozone played a secondary role. FAHP was established on the basis of environmental impact, economic benefit, and energy consumption. Comprehensive evaluation by FAHP demonstrated that D3 (with an ozone dosage of 2.0 g/H, a catalyst dosage of 62.5 g/L, initial pH of 9, reaction time of 80 min, and a COD removal rate of 84.96%) was the best operating condition.

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