scholarly journals Effect of Acceleration and Deceleration Power Exercises on improving Offensive Move without a Ball in Juniors’ Basketball matches

2021 ◽  
Vol 0 (0) ◽  
pp. 0-0
Author(s):  
Sara Moselhy
Keyword(s):  
Acceleration And Deceleration

Experimental and Numerical Analysis of a Motorcycle Air Intake System Aerodynamics and Performance

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
M. A. Abd Halim ◽  
N. A. R. Nik Mohd ◽  
M. N. Mohd Nasir ◽  
M. N. Dahalan
Keyword(s):  
Combustion Process ◽  
Three Dimensional ◽  
Engine Performance ◽  
Internal Flow ◽  
Rapid Expansion ◽  
Navier Stokes ◽  
Turbulent Fluctuation ◽  
Ansys Fluent ◽  
Induction System ◽  
Acceleration And Deceleration

Induction system or also known as the breathing system is a sub-component of the internal combustion system that supplies clean air for the combustion process. A good design of the induction system would be able to supply the air with adequate pressure, temperature and density for the combustion process to optimizing the engine performance. The induction system has an internal flow problem with a geometry that has rapid expansion or diverging and converging sections that may lead to sudden acceleration and deceleration of flow, flow separation and cause excessive turbulent fluctuation in the system. The aerodynamic performance of these induction systems influences the pressure drop effect and thus the engine performance. Therefore, in this work, the aerodynamics of motorcycle induction systems is to be investigated for a range of Cubic Feet per Minute (CFM). A three-dimensional simulation of the flow inside a generic 4-stroke motorcycle airbox were done using Reynolds-Averaged Navier Stokes (RANS) Computational Fluid Dynamics (CFD) solver in ANSYS Fluent version 11. The simulation results are validated by an experimental study performed using a flow bench. The study shows that the difference of the validation is 1.54% in average at the total pressure outlet. A potential improvement to the system have been observed and can be done to suit motorsports applications.

scholarly journals Changes of Walking Activity During the First Cycle Phases of COVID-19 Pandemic: A Case Study of Seoul, Korea

2021 ◽  
pp. 193758672110265
Author(s):  
Youngjun Park ◽  
Haekwon Chung ◽  
Sohyun Park
Keyword(s):  
Public Health ◽  
Physical Inactivity ◽  
Voluntary Participation ◽  
Walking Activity ◽  
Significant Difference ◽  
Before And After ◽  
Acceleration And Deceleration ◽  
Preliminary Study ◽  
The Government

Aim: This study explores the changes in regular walking activities during the phases of the pandemic. Background: With the spread of COVID-19 transmission, people are refraining from going out, reducing their physical activity. In South Korea, COVID-19 broke out in the 4th week of 2020 and experienced the first cycle phases of the pandemic, such as outbreak, widespread, and decline. In response to the pandemic, the government encouraged voluntary participation in social distancing campaigns, and people reduced their outside activities. Methods: This article examines the decrease and increase of the Prevalence of Regular Walking (≥30 min of moderate walking a day, on ≥5 days a week) by the COVID-19 phases. This study is based on weekly walking data for 15 weeks in 2020, via the smartphone healthcare app, which is managed by 25 public health offices of the Seoul government. Results: According to the findings, the level of prevalence of regular walking (PRW) has a significant difference before and after the outbreak, and every interval of the four-stage COVID-19 phases, that is, pre-pandemic, initiation, acceleration, and deceleration. The level of PRW sharply decreased during initiation and acceleration intervals. In the deceleration interval of COVID-19, the PRW kept increasing, but it has not yet reached the same level as the previous year when the COVID-19 did not exist. Conclusions: As a preliminary study, this study explains empirically how COVID-19 changed PRW in Seoul. It would be helpful to enhance our understanding of the changes in physical inactivity in the pandemic period.

Investigations on the positioning accuracy of the Nano Fabrication Machine (NFM-100)

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jaqueline Stauffenberg ◽  
Ingo Ortlepp ◽  
Ulrike Blumröder ◽  
Denis Dontsov ◽  
Christoph Schäffel ◽  
...  
Keyword(s):  
Target Position ◽  
Repeated Measurements ◽  
Scanning Probe ◽  
Measuring System ◽  
Direct Drive ◽  
Positioning Accuracy ◽  
Scanning Probe Lithography ◽  
Nano Fabrication ◽  
Atomic Force ◽  
Acceleration And Deceleration

Abstract This contribution deals with the analysis of the positioning accuracy of a new Nano Fabrication Machine. This machine uses a planar direct drive system and has a positioning range up to 100 mm in diameter. The positioning accuracy was investigated in different movement scenarios, including phases of acceleration and deceleration. Also, the target position error of certain movements at different positions of the machine slider is considered. Currently, the NFM-100 is equipped with a tip-based measuring system. This Atomic Force Microscope (AFM) uses self-actuating and self-sensing microcantilevers, which can be used also for Field-Emission-Scanning-Probe-Lithography (FESPL). This process is capable of fabricating structures in the range of nanometres. In combination with the NFM-100 and its positioning range, nanostructures can be analysed and written in a macroscopic range without any tool change. However, the focus in this article is on the measurement and positioning accuracy of the tip-based measuring system in combination with the NFM-100 and is verified by repeated measurements. Finally, a linescan, realised using both systems, is shown over a long range of motion of 30 mm.

scholarly journals Assessment of the Multi-Location External Workload Profile in the Most Common Movements in Basketball

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3441
Author(s):  
Carlos D. Gómez-Carmona ◽  
Sebastián Feu ◽  
José Pino-Ortega ◽  
Sergio J. Ibáñez
Keyword(s):  
Lower Limb ◽  
Repeated Measures ◽  
Ad Hoc ◽  
Physical Conditioning ◽  
Lumbar Region ◽  
Basketball Players ◽  
Eta Squared ◽  
Subject Variability ◽  
Acceleration And Deceleration ◽  
Linear Movement

The present study analyzed the multi-location external workload profile in basketball players using a previously validated test battery and compared the demands among anatomical locations. A basketball team comprising 13 semi-professional male players was evaluated in five tests (abilities/skills/tests): (a) aerobic, linear movement, 30-15 IFT; (b) lactic anaerobic, acceleration and deceleration, 16.25 m RSA (c) alactic anaerobic, curvilinear movement, 6.75 m arc (d) elastic, jump, Abalakov test (e) physical-conditioning, small-sided game, 10’ 3 vs.3 10 × 15 m. PlayerLoadRT was evaluated at six anatomical locations simultaneously (interscapular line, lumbar region, knees and ankles) by six WIMU PROTM inertial devices attached to the player using an ad hoc integral suit. Statistical analysis was composed of an ANOVA of repeated measures and partial eta squared effect sizes. Significant differences among anatomical locations were found in all tests with higher values in the location nearer to ground contact (p < 0.01). However, differences between lower limb locations were only found in curvilinear movements, with a higher workload in the outside leg (p < 0.01). Additionally, high between-subject variability was found in team players, especially at lower limb locations. In conclusion, multi-location evaluation in sports movements will make it possible to establish an individual external workload profile and design specific strategies for training and injury prevention programs.

scholarly journals Ambulance deceleration causes increased intra cranial pressure in supine position: a prospective observational prove of principle study

2021 ◽  
Vol 29 (1) ◽  
Author(s):  
Iscander M. Maissan ◽  
Boris Vlottes ◽  
Sanne Hoeks ◽  
Jan Bosch ◽  
Robert Jan Stolker ◽  
...  
Keyword(s):  
Supine Position ◽  
Scientific Evidence ◽  
Injured Patient ◽  
Upright Position ◽  
Fluid Shift ◽  
Nerve Sheath ◽  
Head Injured ◽  
Acceleration And Deceleration ◽  
Pressure Changes ◽  
Intra Cranial Pressure

Abstract Background Ambulance drivers in the Netherlands are trained to drive as fluent as possible when transporting a head injured patient to the hospital. Acceleration and deceleration have the potential to create pressure changes in the head that may worsen outcome. Although the idea of fluid shift during braking causing intra cranial pressure (ICP) to rise is widely accepted, it lacks any scientific evidence. In this study we evaluated the effects of driving and deceleration during ambulance transportation on the intra cranial pressure in supine position and 30° upright position. Methods Participants were placed on the ambulance gurney in supine position. During driving and braking the optical nerve sheath diameter (ONSD) was measured with ultrasound. Because cerebro spinal fluid percolates in the optical nerve sheath when ICP rises, the diameter of this sheath will distend if ICP rises during braking of the ambulance. The same measurements were taken with the headrest in 30° upright position. Results Mean ONSD in 20 subjects in supine position increased from 4.80 (IQR 4.80–5.00) mm during normal transportation to 6.00 (IQR 5.75–6.40) mm (p < 0.001) during braking. ONSD’s increased in all subjects in supine position. After raising the headrest of the gurney 30° mean ONSD increased from 4.80 (IQR 4.67–5.02) mm during normal transportation to 4.90 (IQR 4.80–5.02) mm (p = 0.022) during braking. In 15 subjects (75%) there was no change in ONSD at all. Conclusions ONSD and thereby ICP increases during deceleration of a transporting vehicle in participants in supine position. Raising the headrest of the gurney to 30 degrees reduces the effect of breaking on ICP.

Epitasis and Anesis in Aristotle, De caelo 2.6

Phronesis ◽  
2016 ◽  
Vol 61 (1) ◽  
pp. 33-42 ◽  
Author(s):  
Stephen E. Kidd
Keyword(s):  
The Other ◽  
Irregular Motion ◽  
Acceleration And Deceleration ◽  
The One

De caelo 2.6 describes irregular motion differently from the discussion at Physics 5.4. The desire to make the one discussion congrue with the other has strained interpretation of the De caelo passage. Aristotle provides a theory of irregular motion that is tripartite and the passage ought to be interpreted in such a way as to explain this tripartite motion. Akmē is not a ‘top speed’ as it is generally translated, but a point in an object’s motion when epitasis must become anesis. Although the terms epitasis and anesis cover ‘acceleration’ and ‘deceleration’ they cannot be reduced to them.

A Response-Time Approach for Estimating Sensitivity to Auditory Tempo Changes

2005 ◽  
Vol 22 (3) ◽  
pp. 389-399 ◽  
Author(s):  
Marc Pouliot ◽  
Simon Grondin
Keyword(s):  
Response Time ◽  
Auditory System ◽  
Relative Sensitivity ◽  
Psychophysical Method ◽  
Dynamic Stimuli ◽  
Tempo Change ◽  
Sensitive Tool ◽  
Acceleration And Deceleration ◽  
Musical Condition ◽  
Method Of Constant Stimuli

One of the features of the auditory system is its ability to efficiently process events that occur in rapid succession. The aim of the present study is to propose a new way of investigating sensitivity to auditory tempo changes. More specifically, it proposes to compare the relative sensitivity (bias) to acceleration and deceleration in both musical and monotonal conditions. Bias was measured with (1) a conventional psychophysical method known as the method of constant stimuli (MCS) and (2) a so-called method of dynamic stimuli (MDS). The latter method consists in responding with a finger press as soon as a near-continual tempo change is detected. With the MCS, there was no preference, as estimated by the point of subjective equality, between acceleration and deceleration in the monotonal condition, but there was a preference in the musical condition that indicated more facility for estimating decelerations than accelerations. The results obtained with the MDS are consistent with the MCS results, given that the response time was faster for decelerations than accelerations in the musical condition but not in the monotonal condition. We conclude that the MDS is a sensitive tool for investigating slight tempo variations.

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