scholarly journals Designing method of acceleration and deceleration control schedule for variable cycle engine

2020 ◽  
Author(s):  
Linyuan JIA ◽  
Yuchun CHEN ◽  
Ronghui CHENG ◽  
Tian TAN ◽  
Keran SONG
Keyword(s):  
Acceleration And Deceleration ◽  
Designing Method

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.

Proposal for Designing Method of Radio Transmission Range to Improve Both Power Saving and Communication Reachability Based on Target Problem

2016 ◽  
Vol E99.B (11) ◽  
pp. 2271-2279
Author(s):  
Ryo HAMAMOTO ◽  
Chisa TAKANO ◽  
Hiroyasu OBATA ◽  
Masaki AIDA ◽  
Kenji ISHIDA
Keyword(s):  
Power Saving ◽  
Transmission Range ◽  
Target Problem ◽  
Designing Method

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.

Pulp pumping efficiency II – Designing of a pulp pump

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Qihua Zhang ◽  
Shun Kang ◽  
Zhiang Xie ◽  
Li Cao ◽  
Zhaoxu Yan ◽  
...  
Keyword(s):  
Optimization Procedure ◽  
Tip Clearance ◽  
Impeller Blade ◽  
Pumping System ◽  
Pumping Efficiency ◽  
Erosion Corrosion ◽  
Efficiency Increase ◽  
Set Up ◽  
Designing Method ◽  
Optimal Designing

Abstract Based on the loss model of pulp pump set up in the I part of this research, an efficient designing method is proposed by taking account of the influences of head reduction by small blade number, leakage loss via tip clearance, and erosion-corrosion wears in pumps separately. Further, a two-stage optimal designing approach was proposed to tackle the oversized design. The pump designing was performed by coupling with a CFD-based optimization procedure. An efficiency increase of near 10 % was achieved on the pump model validated in laboratory. It was proved that performance could be improved by increasing the impeller blade width and enlarging the impeller blade outlet angle. It was further shown that the erosion-corrosion wear in pulp pump was relatively lighter when compared to particle-impingement wear in slurry and sewage pump. Adoption of composite material showed potential in energy-saving in the pumping system.

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.

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