Sepaktakraw: A Descriptive Analysis of Heart Rate and Blood Lactate Response and Physiological Profiles of Elite Players

( Abdul Rashid Aziz ),( Eikman Teo ),( Benedict Tan ),( Kong Chuan Teh ) 한국스포츠정책과학원(구 한국스포츠개발원) 2003 International Journal of Applied Sports Sciences Vol.15 No.1

The purpose of this study was to gain insights into the physical demands of the sport of sepaktakraw and the physiological profiles of elite players. The temporal characteristics of matches (i.e. duration of rally, recovery, set and match) and physiological responses (i.e. heart rate (HR) and blood lactate [La]) of the players during matches were measured. Match duration ranged from 20.7 to 50.8 min. Mean duration of rallies and recovery between rallies were 5.5 and 9.8 s, where 73% of the rallies lasted < 6 s. [La] ranged from 1.2 to 8.8 mMo1·L(-1). These data suggested a dominant involvement of the anaerobic energy systems in sepaktakraw, in particular the alactic energy system. The mean HR of ~153 beats ·min(-1) indicated that the intensity of sepaktakraw match-play was moderate. National-level players (N = 22) were assessed for anthropometry, maximal oxygen uptake, anaerobic power and work capacity for 10 and 30 s, and vertical jump. There were no significant differences between the three positional roles (i.e. spikers, feeders and servers) in all the measures, except for height. Relative to elite athletes of other intermittent sports, the sepaktakraw player possessed excellent jumping power and ability to perform high-intensity anaerobic work, but lower aerobic fitness. The players` fitness attributes concurred well with their physiological responses and the temporal characteristics during match-play.

Correlation between Tests of Running Repeated Sprint Ability and Anaerobic Capacity by Wingate Cycling in Multi-Sprint Sports Athletes

( Abdul Rashid Aziz ),( Teh Kong Chuan ) 한국스포츠정책과학원(구 한국스포츠개발원) 2004 International Journal of Applied Sports Sciences Vol.16 No.1

The 30 s Wingate cycling (cWG) test is a popular test of anaerobic capacity. The test is highly correlated with short, high-intensity performance but may have limitations when assessing intermittent-type activities. A reliable field-based test, the running Repeated Sprint Ability (rRSA) test, is deemed more sport-specific than cWG in determining anaerobic performance of multi-sprint sports athletes. This study examines the relationship of the performance indices of cWG and rRSA (8×40 m with 30 s rest in-between) tests in well-trained multi-sprint sports athletes. Twenty-six National-level male field hockey and soccer players took the cWG and rRSA tests on separate occasions in random order. There were only modest correlations between the cWGs mean power (relative) and rRSAs total sprinting time (r = -.46, p < .05) and between the two tests fatigue indicators (r = .46, p < .05). The findings of the low-shared variance among the performance variables between the two tests provided limited support for the use of the cWG for assessing the anaerobic performance capability of well-trained multi-sprint sport athletes.

Effect of Thirty Days Supplementation of Standardized Lingzhi Extract on Aerobic, Anaerobic and Strength Parameters in Trained Athletes

( Abdul Rashid AZIZ ),( Patrick O. L. GOH ),( Kong Chuan TEH ) 한국스포츠정책과학원(구 한국스포츠개발원) 2006 International Journal of Applied Sports Sciences Vol.18 No.1

The mushroom fungus lingzhi (Ganoderma lucidum) has been used for centuries as a traditional health tonic in the Far East. One of its reputed effects, albeit still unproven, is the ability to improve human physical performance. The purpose of this study was to assess the potential ergogenic effects of thirty days of standardized lingzhi extract supplementation on exercise performance. The study adopted a randomized, double-blind, placebo-controlled experimental design. Nineteen players from the men`s national field-hockey team were randomly divided into the experimental (LIN, n = 10) and control (CON, n = 9) groups. All players completed tests for percentage body fat, maximal oxygen uptake, 30 s anaerobic Wingate cycling, and hand-grip strength, at pre- and post-thirty days of supplementation. Throughout the 30 days, the LIN group consumed 440 mg lingzhi extract (dose equivalent to 1.5 g dry fruiting body) daily while the CON group was given an equivalent placebo. All players underwent a similar centralized training programme during the intervention period. There were no significant differences in the physical and performance parameters between the two groups, either at the pre-and post-supplementation stages. In conclusion, chronic daily supplementation days of 440 mg lingzhi extract for thirty-days did not enhance training related gains in the aerobic, anaerobic and strength parameters in well-trained field-hockey players.

Prediction of the phase distribution of diesel/CNG bubbly flow in a horizontal pipe under the influence of a magnetic field

Hasanain A. Abdul Wahhab,A. Rashid A. Aziz,Hussain H. Al-Kayiem,Mohammed S. Nasif,Lukmon O. Afolabi 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.11

This paper describes an analytical study of the magneto hydrodynamics of small CNG bubbles in laminar horizontal diesel flow under the influence of a magnetic field. The investigation is based on experiments carried out to identify the effect of varying the magnetic field intensity on the trajectory, the formation of bubbles and their shape and velocity in the flow. Different images at different positions downstream of the CNG bubbles injection point were captured by a high speed camera and analyzed by image processing techniques provided information on bubble velocity, bubbles size, spatial location and gas area fraction as a function of changing the magnetic field intensity. The outcomes confirmed that CNG bubbles under magnetic field grow up vertically to an elliptical shape in the diesel phase with a mean diameter about twice that of the original bubble. It was also noticed that the velocity of the CNG bubbles decreased as the strength of the magnetic field increased.

Identification of dominant structures and their flow dynamics in the turbulent two-phase flow using POD technique

Shahzad Munir,Muhammad Israr Siddiqui,Morgan Heikal,Abdul Rashid Abdul Aziz,Guillaume de Sercey 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.11

The Proper orthogonal decomposition (POD) method has seen increasingly used in the last two decades and has a lot of applicationsfor the comparison of experimental and numerically simulated data. The POD technique is often used to extract information about coherentstructures dominating the flow. The two-dimensional and two-component instantaneous velocity fields of both liquid and gas phasesof a slug flow were obtained by Particle image velocimetry (PIV) combined with Laser induced fluorescence (LIF). POD was applied tothe velocity fields of both phases separately to identify the coherent flow structures. We focused on POD eigenmodes and their correspondingenergy contents of both liquid and gas phases. The sum of first few eigenmodes that contain maximum turbulent kinetic energyof the flow represents the coherent structures. In the case of liquid phase the first eigenmode contained 42% of the total energy, while inthe gas phase the decaying energy distribution was flat. The POD results showed that the coefficient of mode 1 for the liquid phase oscillatedbetween positive and negative values and had the highest amplitude. For the visualization of coherent motion different linear combinationsof eigenmodes for liquid and gas phases were used. The phenomena of turbulent bursting events associated with Q2 events(low momentum fluid moving away from the wall) and Q4 events (high momentum flow moving towards the wall) were also discussedto assess its contribution in turbulence production.

Recent developments of regenerative magnetorheological (RMR) damper: A review

Sakib Muhammad Mohtasim,Rubel Ahammed,Md. Mahfujur Rahman,Md Mahbubur Rashid,Rupal Roy,Abdul Aziz 한국유변학회 2021 Korea-Australia rheology journal Vol.33 No.3

Magnetorheological (MR) dampers are becoming popular smart devices with controllable higher damping properties. This paper presents an inclusive review of energy harvesting MR dampers. The classifications of energy harvesting MR dampers, operating principles, structural design, mathematical models, fluid models, experimental investigation, and applications are classified and reviewed. The regenerative MR dampers have self-power capability, and self-sensing capability to control higher performance and it is an important feature of regenerative MR dampers. The review indicates that regenerative MR dampers have enough power generation capacity to power MR dampers and higher damping performances. It has been found that a single-ended monotube regenerative MR (RMR) damper has maximum power generation capabilities than other RMR dampers.

Stress and damping of wide cantilever beams under free vibration

Faruq Muhammad Foong,Thein Chung Ket,Ooi Beng Lee,Abdul Rashid Abdul Aziz 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.1

Research has shown that the damping of a vibrating structure is highly dependent on its stress function. In this study, the bending stress and damping of wide cantilever beams under free vibration were analyzed using the classical plate and beam theory. The damping stress equation for cantilever beams under free vibration was derived based on the empirical function of unit dissipating energy, whereas the plate bending equation was derived using the double finite integral transform method. The bending stress and damping ratio results from the beam and the plate theory were compared with simulation results from finite element analysis (FEA) for different length-to-width ratios. Results show that the plate theory displayed a good agreement with FEA results in terms of estimated value and trending curve shape when a significantly large number of terms were used. Using a small number of terms resulted in large errors at high length-towidth ratios, but provided sufficient estimates when the length-to-width ratio dropped below four. It was found that the beam theory was only valid for beams with very high length-to-width ratios or square plates. Beyond this ratio, the beam theory recorded a higher error estimate than the plate theory. Overall, the most accurate stress and damping estimations come from the use of plate theory with a very high number of terms.

LTE-Based Passive Bistatic Radar System for Detection of Ground-Moving Targets

Raja Syamsul Azmir Raja Abdullah,Asem Ahmad Salah,Alyani Ismail,Fazirulhisyam Hashim,Nur Emileen Abdul Rashid,Noor Hafizah Abdul Aziz 한국전자통신연구원 2016 ETRI Journal Vol.38 No.2

Use of a passive bistatic radar (PBR) system in the surveillance or monitoring of an area has its advantages. For example, a PBR system is able to utilize any available signal of opportunity (for example, broadcasting, communication, or radio navigation signals) for the purposes of surveillance. With this in mind, there are potentially many research areas to be explored; in particular, the capability of signals from existing and future communication systems, such as 4G and 5G. Long-Term Evolution (LTE) is the world’s most current communication system. Given this fact, this paper presents the latest feasibility studies and experimental results from using LTE signals in PBR applications. Details are provided about aspects such as signal characteristics, experimental configurations, and SNR studies. Six experimental scenarios are carried out to investigate the detection performance of our proposed system on ground-moving targets. The ability to detect is demonstrated through use of the cross-ambiguity function. The detection results suggest that LTE signals are suitable as a source signal for PBR.