A comparison of modal flexibility method and modal curvature method in structural damage detection

Vibration based damage detection techniques examines the changes in dynamic properties of a structure such as frequency, mode shape and damping to indicate the presence of damage. This method is preferred for its ease of implementation, non-destructive nature and its ability to identify damage that is invisible to the surface. Two vibration based damage detection methods are used in this study, namely Modal Flexibility Method and Modal Curvature Method. Although there have been numerous publications on these two methods, there is lack of study on the direct comparison of the methods. Finite element modal analysis of a reinforced concrete slab and steel frame was carried out to obtain the dynamic responses that were used to calculate the Modal Flexibility and Modal Curvature. The structural models were simulated using four damage cases: damage at single location, damage at multiple locations, damage at support location and damage at different damage severities. The comparison of the sensitivity and reliability of Modal Flexibility and Modal Curvature were evaluated using the results of these four damage cases. The results show that the sensitivity and reliability of both methods are affected by the size of the damaged area, its location relative to the support location and the number of damaged segments

Integration of remotely sensed data and GIS in NRCS model / Nuratifah Zaharudin

Rapid and massive (NRCS) was able to calculate the prediction of runoff. The aim of this study is to introduce the capability of remotely sensed data and Geographic Information System (GIS) for NRCS model in Klang River catchments and to overcome the gap for lack of integrated method between GIS application and hydrological model. The first objective of this study is to prepare the landuse information by following the Hydrological Soils Group (HSG) table within catchments’ boundary from satellite imagery as main source. Second, this study aims to combine landuse information and soil classifications to form HSG table through an identified Curve Number (CN) for each intersection in ArcView software. Finally, this study aims to generate runoff value and compute validation with observed data. This study uses Landsat Thematic Mapper (TM) that is able to oversee big areas and could lessen the cost for obtaining landuse information. The research involves three stages of analysis. First, remote sensing technique was used to extract preliminary data. Second, two phases of GIS was involved which are accumulating and programming phase. The third stage that is involved in the research methodology is the validation stage of using SNT model in GIS. In remote sensing technique, 84% of accuracy assessment was obtained with 0.8 kappa value using data processed in 2001 by Landsat TM images. With that achievement, landuse map that contained waterbody, urban, forest, open area and disturbed/transitional area from Landsat TM that represent Klang River catchment was derived. GIS has successfully developed a simulation of NRCS model and graph. Validation stage was done by comparing the simulation of NRCS model from GIS with Observed Unit Hydrograph (OUH). Through validation stage, the SNT model only has an acceptable value of 6% error from the application of 2001 data compared to 12% error from application of 1991 data. Findings from this study have shown that satellite imagery such as Landsat TM are able to provide essential information for hydrology study. The simulation of NRCS model is suitable for monitoring runoff peak of catchment areas

Optimization and tribological properties of semi metallic friction materials / Aznifa Mahyam Zaharudin

The main goal of this work presented in this thesis was to study the tribological properties of newly formulated semi-metallic friction material under different manufacturing parameters, material constituents and friction test parameters. In the first category, the optimization of manufacturing parameters (molding pressure, molding temperature and molding time) for producing the friction materials using powder metallurgy technique were investigated. The optimum manufacturing parameters were determined using Taguchi method where coefficient of friction (COF) and thickness loss were selected as the quality target. These optimal parameters were 500 kN molding pressure, 150oC molding temperature, and 600 seconds molding time. The results revealed that high molding pressure and temperature do not compulsorily produce the best performance in tribological properties. It could be explained by degradation of the resin structure and the loss of binding properties. The investigation also found that adequate molding time was required for sufficient binding of the tested materials. It was also observed that molding pressure has the strongest effect on physical and tribological properties. High molding pressure may cause the binder to separate from the brake friction material, thus less binder to hold the powder particles in the matrix. In the second category, a study was performed to investigate the effect of phenolic resin, rubber, calcium carbonate and graphite on the tribological properties. The samples were prepared under optimum manufacturing parameters

THE PERFORMANCE OF ASP HAL TIC CONCRETE USING VARIOUS FILLERS

Asphalt concretes are made of asphalt binders and aggregates. Although asphalt cement is predominantly considered the binder holding the aggregates together, the actual product used to com1ect larger-size aggregate particles is the asphalt mineral filler mastics. It improves the resistance to permanent deformation in asphalt concrete mixtures by improvement of rheological properties of asphalt binders through a filler effect, and by acting as a microcrack arrester as well as improving the bonding interaction between asphalt binder and aggregates. Samples having different types of filler were prepared and optimum binder content was determined by Marshall Test procedure. Optimum filler content was determined considering the filler/bitumen ratio and filler ratio. Creep test, was carried out to determine the mixture properties and performance. Utilization of waste material as filler material shall reduce cost and contributes to the conservation of the environment without compromising the performance of the asphaltic concrete

Modelling And Control Of A Semi-Active Magnetorheological Damper For Engine Mounting Systems

Multiple operating modes in advanced automotive powertrain technologies such as hybrid propulsion and cylinder deactivation require adaptable engine mounting systems. The use of magnetorheological (MR) fluid dampers for semi-active engine mounting systems offers the prospect of reducing the engine vibration by providing controllable damping forces. Controlling the semi-active engine mounting systems is challenging. The control should not only adequately provide the desired damping forces but also account for the vibration reduction. The aim of this study are to develop a force tracking control for a MR fluid damper model based on the characteristics obtained from the measurements and to assess the effectiveness of the vibration reduction control applied to the semi-active engine mounting system. The MR fluid damper unit was built in-house and was characterized using a damping force test rig. Based on the empirical data, the force tracking control was modelled based on the PI controller in Matlab Simulink software to provide desired damping forces. With sinusoidal forces generated by an electric motor, a scale model of three-degree-of-freedom (3-DOF) passive engine mounting system was built in-house to verify a mathematical model developed using the software. Then the 3-DOF model was added with the MR fluid damper model and the vibration attenuation control was applied to the semi-active engine mounting system using the Fuzzy-Tuned-PID controller. The results show the controller gives improvements in terms of Root mean square (RMS) and maximum peak variation as compared to the passive system

The Impact of Dividend Payout Ratio on Future Earnings Growth: Evidence from Malaysia

It is argued that the payout ratio has positive impact on future earnings growth as suggested by Arnott and Asness (2003) and Zhou and Ruland (2006). The aim of this study is to determine the impact of dividend payout ratio on future earnings growth in Malaysia. There was no study in Malaysia that emphasizes on the influence of dividend payout on future earnings growth. The study uses 97 listed companies on Bursa Malaysia as sample, with 485 company-year observations. The regression analysis shows that dividend payout ratio has no impact on future earnings growth. The nature of companies' ownership in Malaysia is the possible explanation for the results

Command shaping techniques for vibration control of a flexible robot manipulator

This paper presents an investigation into development of feed-forward control strategies for vibration control of a flexible robot manipulator using command shaping techniques based on input shaping, low-pass and band-stop filtering. A constrained planar single-link flexible manipulator is considered and the dynamic model of the system is derived using the finite element method. An unshaped bang–bang torque input is used to determine the characteristic parameters of the system for design and evaluation of the control techniques. Feed-forward controllers are designed based on the natural frequencies and damping ratios of the system. Simulation results of the response of the manipulator to the shaped and filtered inputs are presented in time and frequency domains. Performances of the techniques are assessed in terms of level of vibration reduction at resonance modes, speed of response, robustness and computational complexity. The effects of number of impulse sequence and filter order on the performance of the system are investigated. Finally, a comparative assessment of the input shaping and input-filtering techniques is presented and discussed

Mufti Muḥammad Taqī ‘Usmānī and his scholarly contribution to the Qur’anic studies: Mufti Muhammad Taqī ‘Usmānī dan sumbangan ilmiahnya dalam bidang al-Quran

Mufti Taqī ‘Usmānī of Pakistan is one of the most prominent contemporary Muslim scholars from Deobandi and Waliyullah’s School of Thought. He is not only a leading living scholar of Islamic Jurisprudence and Islamic finance, but also a scholar and an intellectual of the Quran, the Hadith, Islamic law, and comparative religion. He has always been placed among the top fifty in “The 500 Most Influential Muslims” in the world from 2009 until 2016. His works on the sciences of the Quran and the interpretation of the Holy Quran show his scholarship in this field. The writing of “Ulūm Al-Qur’ān” (An Approach to the Quranic Sciences in Urdu), “The Meanings of the Noble Qur’ān” (English translation of the Quran) and “Āsān Tarjamah Qur’ān” (The simple translation of the Quran with notes in Urdu) are his major works in the field of Quran. His supervision of translating the “Ma‘ārif al-Qur’ān” of his father, Maulānā Mufti Shāfi‘, from Urdu to English is considered as his magnificent endeavor and contribution to this field. This paper aims to discover the biography of Mufti Taqī ‘Usmānī and his scholarly contribution towards the interpretation of the Holy Quran in the above-mentioned works. The paper uses a descriptive-analytical approach to discuss his biography and his contributions. The analysis shows that Mufti Taqī ‘Usmānī is a continuity of Waliyullah’s tradition and Deobandi scholars’ in contributing Quranic teaching to ordinary people as well as scholars through his writings and his other scholarly works.

The influence of tualang honey in tensile strength and microscopic aspect (fibroblast and epithelization) of laparatomy wound healing in malnourished rabbits

Based on published reports that honey accelerates wound healing, an investigation on its role in laparotomy wound healing in term of tensile strength and microscopic aspect (fibroblast and epithelialization) on malnourished rabbits was carried out. Forty six female New Zealand white rabbits at the age of 6 weeks, weighing about 2 to 3 kg had a 4 centimeter infraumbilical laparatomy wound inflicted on their abdomen. They were divided into three groups which were malnourished group treated with topical and oral used of honey, malnourished and well-nourished group treated with topical and oral used of normal saline. Wound dressing was done every day and any changes over the wound were documented. The mechanical strength and histopathological examination were more favorable toward the malnourished group treated with topical and oral used ofTualang honey. The malnourished group treated with topical and oral used Tualang honey displayed a better tensile strength result compared to malnourished and well-nourished group treated with topical and oral used of normal saline at day 7 and 14 ( P<0.05 ) . For histopathological examination, both parameter epithelial and fibroblast count were also favorable towards the malnourished group treated with topical and oral used Tualang honey. The epithelial and fibroblast count were better in the malnourished group treated with the topical and oral used Tualang honey compared to malnourished and well-nourished group treated with topical and oral used of normal saline at day 7 and day 14 ( P<0.05 ). However, there were no significant difference in epithelial count for the malnourished group treated with topical and oral used Tualang honey compared to well-nourished group treated with topical nad oral used normal saline in day 14 ( P>0.05 ). Our study suggest that oral and topical Tualang honey dressing enhances the laparotomy wound healing in malnourished rabbits by increasing the numbers of fibroblast and epithelial cells which lead to increased wound strength

Attitude, Leadership Style, Awareness, and Readiness of Academic Staff Towards Deaf Student Acceptance in Saudi Arabia

The study explores faculty attitudes, leadership styles, awareness, and readiness towards deaf students in Makkah, Saudi Arabia. 327 university faculty members participated, and quantitative analysis was conducted using SPSS and Smart-PLS. The findings demonstrate positive attitudes and leadership styles among Saudi faculty, leading to acceptance of deaf students. There is a significant relationship between variables, with faculty attitude positively influencing readiness for admitting deaf students. The study reveals an encouraging situation in Saudi Arabia, with faculty prepared to embrace deaf students. Transactional, transformational, and laissez-faire leadership styles are positively associated with acceptance. Increasing faculty awareness, particularly in special education, is emphasized to enhance readiness. Work experience moderates the relationship between variables. The study supports the Saudi Governments special education initiative and suggests increasing teacher awareness, implementing training programs, and offering tailored social courses for students with disabilities. Despite limitations, the research provides valuable insights into special education in Saudi Arabia