Vulnerability of public buildings subjected to earthquake by finite element modelling

Tremors in Peninsular Malaysia and East Malaysia due to Sumatra and Philippine earthquakes have been reported several times. Engineers are concerned of the seismic vulnerability of public buildings due to lack of earthquake consideration in Malaysia’s building design procedure. This study addresses the vulnerability of public buildings in Malaysia subjected to earthquakes from Sumatra and Philippines. A case study has been conducted on low rise to medium rise reinforced concrete buildings, which are mostly categorized as moment resisting frames. The buildings are analyzed using Finite Element Modeling (FEM) under different types of analyses including Free Vibration Analysis (FVA), and Time History Analysis (THA) considering low to medium earthquake intensities. The study indicates that more than 50% of the buildings produced dynamic amplification factors of slightly more than one indicating not much of a dynamic response to the buildings. The performances of the structure are shown by the yield point at beam-column connections where the internal forces at beam elements exceed the design capacity of the beams. In the non-linear analysis, the largest damage index is still under the intermediate level where no structural damage is indicated, but some non-structural damage are expected

A framework for six-sigma implementation in rubber manufacturing industry – an innovation between DMAIC cycle and quality improvement tools

Quality improvement tools are commonly utilised by the industries to attain quality products and benefits like reduction in scrap cost and wastes. In order to achieve the proper implementation of quality tools, a theoretically developed framework inclusive of six-sigma DMAIC (Define, Measure, Analyse, Improve & Control) cycle is required. Also, the quality tools associated at each stage has thoroughly implemented on a case study which carries a real-time issue related to the quality products production. The issue has thoroughly resolved through the right application of quality tools like Failure Modes and effects analysis (FMEA) on the compression moulding technique utilised for the production of Rubber Valve Sleeve Liner (RVSL) under the umbrella of DMAIC cycle. The benefits achieved are 23.1% reduction in scrap rate, 63.8% reduction in Delivery on time (DOT) with savings gained almost RM26,880/month. The relationship between DMAIC cycle and quality tools for quality improvements under the platform of lean six sigma which is highly beneficial for academicians, practitioners and engineering managers working in this field with a limitation of implementation only in the rubber manufacturing industry. In future, the developed framework should be implemented in some other manufacturing industries

Intelligent optimization of novel particle swarm optimization with explorer (PSOE) for identification of flexible manipulator system

Flexible manipulator is widely used in robotics and mechanical systems. Its application have led to the development of systems which are lighter, less bulky, and provides greater system flexibility. However, the flexible manipulator has one drawback. It develops unwanted vibration during operation which reduced the efficiency of the flexible manipulator systems for accurate positioning requirements. Therefore, an intelligent optimizer, the Particle Swarm Optimization with Explorer (PSOE) was developed to model this highly non-linear and complex system. Initially, an experimental setup for the flexible manipulator was developed. Experimental input output data were acquired including hub angle and endpoint acceleration to fed into system identification method. Next, optimization was done using the proposed PSOE as compared to a standard Particle Swarm Optimization (PSO) algorithm via linear auto regressive with exogenous (ARX) model structure. Validations of the algorithms were attained on the basis of minimizing the value of mean-squared error (MSE) and correlation tests. The superiority of the added ‘explorer’ to the algorithm was confirmed as PSOE obtained the lowest MSE value of 2.8232 × 10–5 and 3.7364 × 10–7 for end-point acceleration and hub angle modelling, respectively. Both modelling also achieved good correlation values within the 95% confidence interval. Results obtained can be adapted for further analysis in implementing an active vibration control for flexible manipulator systems

PROTECTIVE EFFECT OF CHLORELLA VULGARIS ON DNA DAMAGE, OXIDATIVE STRESS, AND LUNG MORPHOLOGICAL CHANGES IN CIGARETTE SMOKE-EXPOSED RATS

Objective: The aim of this study was to determine the protective effect of Chlorella vulgaris (ChV), antioxidant-rich unicellular green alga, and in cigarette smoke-exposed rats.Methods: Male Sprague Dawley rats were divided into 4 groups: Control Group (C), ChV group (300 mg/kg body weight), cigarette smoke-exposed (S) group, and S group treated with ChV (S+ChV). Blood samples were drawn from the orbital sinus on days 0, 15, and 30 for the determination of DNA damage by Comet assay and plasma malondialdehyde (MDA) using high-performance liquid chromatography. Rats were killed on day 30, and lung tissue samples were taken for the evaluation of airspace enlargement and number of inflammatory cells.Results: Increased DNA damage (1004.8 au + 329.2, day 15; 1102.7 + 197.8, day 30) and high MDA levels (10.66 + 0.27, day 15; 10.29 + 0.9 day 30) were found in cigarette smoke-exposed rats on days 15 and 30 but were reduced significantly (p<0.05) when treated with ChV (DNA: 482.6 + 223.3, day15; 423.5 + 74.6, day 30 and MDA: 6.1 + 0.6, day15; 6.6 + 2.5, day 30) for both days. Hematoxylin and eosin staining showed that cigarette smoke-exposed rats had high frequency of airspace enlargement and number of inflammatory cells which were reduced when treated with ChV.Conclusion: ChV has a protective role in cigarette smoke-exposed rats by reducing oxidative DNA damage, MDA levels, lung cells inflammation, and airspace enlargement