Extensive Tracking Performance Analysis of Classical Feedback Control for XY Stage Ballscrew Drive System

Performance analysis in term of identifying the system's transient response, stability and system's dynamical behavior in control system design is undeniably a must process. There are several ways in which a system can be analyzed. An example of well known techniques are using time domain and frequency domain approach. This paper is focused on the fundamental aspect of analysis of classical feedback controller in frequency domain of XY milling table ballscrew drive system. The controller used for the system is the basic PID controller using Matlab SISOTOOL graphical user interface. For this case, the frequency response function (FRF) of the system is used instead of using estimated model of transfer function to represent the real system. Result in simulation shows that after proper tuning of the controller, the system has been successfully being controlled accordingly. In addition, the result also fulfill the set requirement of frequency domain analysis in terms of the required gain and phase margin, the required maximum peak sensitivity and complimentary sensitivity function and the required stability

Enhancing the corrosion resistance of reinforcing steel under aggressive operational conditions using behentrimonium chloride

Aggressive operational conditions e.g. saline media and acidic gases, e.g., CO2 can increase the corrosion rate of reinforcing steel. Accordingly, the necessity to protect the steel under the above conditions without affecting the mechanical properties of the concrete is growing. Herein, the inhibition efficiency of a new corrosion inhibitor, behentrimonium chloride (BTC, C25H54ClN), is explored in a simulated-concrete pore solution (SCP) with 3.5 wt.% NaCl at different pH using electrochemical impedance spectroscopy (EIS) and polarization methods. Using only a 50 ?mol L?1 of BTC, we are able to measure an inhibition efficiency of 91, 79, and 71% in SCP solution with 3.5% NaCl at pH of 12.5, 10 and 7, respectively without showing any effect on the mechanical properties on the cured mortars. Temkin isotherm is used to describe the physisorption of BTC inhibitor on the steel surface. Also, the adsorption and influence of the inhibitor on the metal surface are characterized using the scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. In conclusion, this new inhibitor shows high corrosion inhibition efficiencies under different aggressive conditions and can be used in concrete to reduce the corrosion rate of reinforcing steel without decreasing the mechanical properties of the concrete. - 2019, The Author(s).The publication of this article was funded by the Qatar National Library.Scopu

Establishing reliability of performance indicator of sepak takraw using notational analysis

The aim of this study is to establish the necessary reliability in the notational analysis of sepak takraw. Two performance analysts were recruited to help in the collection of the data. The performances  were  analyzed based  on  the  main performance  indicators  relevant  to  the demand of the game. Cronbach’s alpha and Cohen’s kappa reliability testing was implemented to test the reliability of the information collected. The results for reliability shows [α = 0.91 and K = 0.89 (0.092, 95%), p < 0.05] respectively, which confirmed the reliability of the information  collected  from the  analysis.  This  paper  has revealed  that  reliability  in  the notational analysis could be achieved. Performance analysts should ensure the reliability of their analysis before being relayed to the coach.Keywords: sepak takraw; performance indicators; notational analysis; reliabilit

MALAYSIAN INNOVATION ECOSYSTEM: A REVIEW OF THE LITERATURE

The capability to innovate and to bring innovation successfully to the market will be a crucial determinant of the global competitiveness of nations over the next decade. Knowing the importance, Malaysia has started to prioritise its national agenda by embedding innovation as one of the major theme of its national economic model. Building a sustainable and supportive ecosystem is one of the keys to ensure an efficient growth strategy. By succeeding in building the sustainable self-reliant innovative system needed, the country aims to become a fully developed nation strategically positioned in the regional and global economic landscape. This paper provides a review of the literature on current status of Malaysian innovation eco-system. The paper concludes that innovation eco-system is essential to nurture innovation in organisation

Notational analysis on tactical passing skills used by collegiate players in an indoor hockey masum tournament

The study aimed to determine the relationship of frequency for wall, diagonal and square passing with the performance for men and women team. Eighteen teams (man = 11; woman = 7) involved in this study. The Pearson correlation coefficient was used to examine the relationship between frequency of use wall pass, diagonal pass and square pass with team performance. Results of the study showed a significant relationship between the frequency of the use of passes to the achievement of the team in both categories. The significant value of wall pass, diagonal pass and square pass for men and women teams is (p < 0.05). Positive relationship indicated team that use more wall, diagonal and square passing was a successful team in tournament. The findings for this study could be used by trainers and individuals who involved in the player development and coaches education.Keywords: indoor hockey; passing skills; wall pass; diagonal pass; square pas

Numerical inspection based on quasi-static analysis using Rousselier damage model for aluminium wingbox aircraft structure

The present paper illustrates a modelling technique of void damage prediction using constitutive Rousselier damage model in wingbox aircraft structure. The high possibility of aluminium wingbox structure to deform during operating become a driving force in this study. The Rousselier model is implemented by the user-defined material subroutine UMAT in the ABAQUS / Standard. The wingbox is a part of a commercially-made commuter aircraft prototype, in which steady aerodynamic pressure is applied as the quasi-static, ranging from cruise load factor until the ultimate load factor. This analysis is divided into three assessments: load factor assessment, damage detection and implementation of Rousselier-UMAT-XFEM (RuX) model solution. The results indicate the maximum stress concentration occurs at the bottom-root part of the skin. The void volume fraction and the crack grow as the load factor increases to the ultimate load factor. A comparison with the literature is shown in some details

Analysis on cracked commuter aircraft wing under dynamic cruise load by means of XFEM

In this paper, a new investigation of crack propagation on a commuter aircraft wing is discussed. The aircraft is a 19-seater multi-purpose commuter aircraft designed for a mission on the remote area. The dynamic load acting on the wing is assumed as harmonic load considering aerodynamic lift at a particular excitation frequency. A 3D wingbox CAD model is developed for the numerical simulation. Extended finite element (XFEM) is applied to analyse the crack propagation on the aircraft wing. The crack growth simulation is successfully done, and the results are shown in some details. These results provided a novel insight on the computational simulation of cracked wing structure under dynamic flight load

Tissue Culture Studies on Fortunella polyandra ‘Nagami’ and ‘Meiwa’

Studies of Fortunella polyandra ‘Nagami’ and ‘Meiwa’ were carried out to observe their responses in tissue culture systems. Explant sources investigated included roots, stems, leaves and cotyledons which were cultured on Murashige and Skoog (MS) medium supplemented with different combinations and concentrations of various hormones. The hormones used were naphthalene acetic acid (NAA) and benzylaminopurine (BAP) at pH 5.8 with a temperature of 23-26°C and a photoperiod of 16 hours light and 8 hours dark. The pH of the media was also altered to include 4.8, 5.8, 6.8 and 7.8. The various explants were subjected to light and dark treatments in order to study the morphogenesis of this species. From the results, it was observed that stem and leaf explants were more responsive than other explants. The best media for regeneration and callus formation was MS supplemented with 0.5 mg/L NAA and 0.5 mg/L BAP at pH 5.8 for ‘Nagami’ and pH 7.8 for ‘Meiwa’. Regeneration was achieved via direct organogenesis and also via callus formation. The highest percentage of shoot formation (40%) was obtained from stem explants (‘Meiwa’) cultured on MS supplemented with 0.5 mg/L NAA and 0.5 mg/L BAP at pH 7.8