Variability In Vibration Input Power From The Structure-Borne Sound Sorce On Plate And Beam Structures

Structure-borne source which transmits vibration power to the supporting structure especially in buildings plays a major role in contributing structure-borne noise. The structureborne sources are also capable of causing damage to the receiver structures. In order to prevent noise radiation and structural failure, it is important to characterise the structureborne sound source and to recognize its potential input power. However, the knowledge of the force excitation behaviors from the structure-borne source which creates variability in the input power is still lacking. To give an effective insight of the structural mechanism excited by the structure-borne source, some uncertainties such as the amplitude, excitation phase and location of the excitation force which create the variability in the input power are modelled in this study. Quantification of the uncertainties of the maximum-minimum bands, frequency-averaged mean and variance are obtained from the variability of input power in the infinite and finite structures. It is shown that the variability of the input power reduces as the frequency increases. It is also found that the quantifications of the variability from the finite structure can also be approached using the infinite structure. For characterisation of the structure-borne sound source, thin and thick reception structures are used for the velocity source and the force source assumptions in the reception plate test. It is shown that, the reception plate for the force source assumption, the averaging spatial response across the plate area having low modal density is found to be problematic due to high variability of the plate velocity. Therefore, to obtain a more representative spatially averaged mean-squared velocity, only response points closed to the contact points are taken into account in the calculation. The results show that the measured source mobility from the reception plate is improved. Characterisation using a beam structure is also found feasible in the ’reception structure technique’

Factors that influence public awareness towards Takafulink Wanita Plan offered by MAA Takaful Berhad, Seremban branch / Noor Fariza Edora Zainudin

This study is designed to investigate the public’s awareness towards Takafulink Wanita Plan offered by MAA Takaful Berhad Seremban Branch. Level of income, educational level and sales promotion are the independent variables. The dependent variable is public awareness towards Takafulink Wanita Plan. The objective of the study is to investigate the level of public awareness towards Takafulink Wanita Plan, secondly to determine whether there is correlation between independent variables and dependent variable and thirdly to determine the rank that influence public awareness towards Takafulink Wanita Plan. The data set in this study are collected among female employees that work nearby around 1kilometre from MAA Takaful Berhad, Seremban Branch through questionnaires. 100 respondents in that area had become the sample in this study by answering the questionnaires that randomly distributed. The findings indicate there is low level of public’s awareness towards Takafulink Wanita Plan offered by MAA Takaful Berhad. Besides, all the independent variables have correlation with the public’s awareness and educational level is the first rank that influence the public’s awareness towards Takafulink Wanita Plan. There are also several recommendations that researcher suggest based on the findings

CHARACTERIZATION OF A STRUCTURE- BORNE SOURCE USING THE RECEPTION PLATE METHOD

This paper presents the characterization of vibration strength obtained from reception plate method by applying the mobility concepts. It describes a laboratorybased measurement procedure, which determines the strength of a vibration source in terms of the total squared free velocity of the source. The source used in the experiment is the small electric fan motor installed on high mobility aluminum panel in order to neglect the influence of the source mobility. The complexity of the mobility at the contact points are reduced using the single value of effective mobility. The aim is to validate the data obtained from the reception plate method with one from the direct measurement. Thus, this research is expected to give a simple but accurate way to determine input power from a structure-borne sound source

Doing probes diary with children in reporting social networking behaviour

This paper describes the qualitative technique approach in an attempt to understand child personality with regards to social networking sites.It was applied during the user requirement phase.We used a probes diary approach to collect qualitative data from selected children.Seven children from 10-13 years old participated in the study and completed the diary.In this paper, we describe about our probes diary approach with young children participants.We have identified seven important elements in designing diaries for children. We believe that the work presented in this paper might help other researchers to design children's diary for their own research

Structural and optical properties of carbon nanowalls by plasma-enhanced chemical vapor deposition method

Vertically aligned carbon nanowalls (CNWs) were synthesized by catalyst-free 150 MHz high frequency plasma enhanced chemical vapor deposition (PECVD) system, where methane and hydrogen gases were used as the reactive gases. Parametric studies were done to determine the optimum parameters required to obtain tuneable growth of CNWs with favourable properties at high quality film. The parameters included are the optimized temperature, rf power and methane flow-rate. The effects of the growth conditions on the optical properties of the samples were investigated by UV-Vis-NIR spectroscopy and photoluminescence (PL) spectroscopy, while the morphologies and structural properties were characterized by Micro-Raman scattering, Fourier transform infrared (FTIR) spectroscopy and field emission scanning electron microscopy. Shape, density and quality of CNWs were extensively studied and found to be significantly affected by the synthesis parameters. Based on the investigation of the morphologies of catalyst-free CNWs deposited on silicon substrate, it was observed that the optimized parameters have specific range of values. The synthesis temperature, rf power and methane flow-rate are in range of 750-800oC, 10-40 watt and 14-18 sccm, respectively. The morphologies of CNWs produced in different growth conditions looked quite similar but significant thinning of the walls was observed. Wall thickness and height of CNWs were strongly dependent on growth conditions while the lengths were not greatly affected. In Raman spectrum of CNWs, there were four peaks which consist of a low intensity D band, a sharp and strong G band, and low intensity 2D band and D + G band. The intensity ratio of the D band to G band was about 0.15 which indicates a lower number of defects in the CNW structures. FTIR results showed that the absorption band can be associated to the structural vibration of CNWs. From UV-Vis-NIR measurement, the minimum reflectance was found at 0.011 % which indicates that this material is a good candidate for use in a blackbody-like coating. The PL result of the CNW films produced one peak which signifies a narrow opening band gap indicating the presence of an epitaxial bilayer graphene. The energy gap of the CNWs was 1.92 eV which can be regarded as a semiconductor-like characteristic. Tuneable CNWs synthesized using 150 MHz PECVD method can be considered as a good candidate for materials used in optical and optoelectronic devices

Antioxidant and antimicrobial properties of two local edible mushrooms / Noor Fariza Mohammad Fauzi

Antioxidant and antimicrobial activities of Pleurotus ostreatus and Auricularia polytricha extracts obtained with ethanol were investigated in this study. The study was aimed at determining the total phenolic content (TPC) of P. ostreatus and A. polytricha, the antioxidant activity (DPPH free radical-scavenging and FRAP - ferric reducing antioxidant power) and the antimicrobial activity by disc inhibition method. The TPC measured in /xg GAE/mg extract observed in P. ostreatus and A. polytricha were 28.58 ± 0.77 and 31.417 ± 0.75 respectively. Their antioxidant activities were low compared to standards BHA/BHT and ascorbic acid. P. ostreatus showed the stronger radical scavenging activity pattern. The reducing power of P. ostreatus was also higher than that of A. polytricha. Positive correlations were found between total phenolic content in the mushroom extracts and their antioxidant activities. Edible mushrooms may have potential as natural antioxidants. Both mushroom species showed moderate antibacterial activity against both Gram-negative and Gram-positive bacteria tested. The crude extract exhibited mild anticandidal activity on Candida albicans. However, Aspergillus niger has high resistance against both mushrooms species since no inhibition occurred. As conclusion, P. ostreatus showed higher antioxidant activity compared to A. polytricha. Meanwhile, A. polytricha showed better antimicrobial activity than P. ostreatus. From this study, both mushrooms species exhibit the antioxidant and antimicrobial properties, so the extracts could be suitable as antimicrobial and antioxidative agents in the food industry

Trade credit determinants of manufacturing companies in Malaysia

This study examines the determinants of trade credit of manufacturing sector in Malaysia for the period 2013-2017. Utilizing a sample of 114 manufacturing companies listed on Bursa Malaysia, the findings suggest that size negatively influences trade credit, indicating that smaller firms rely more on trade credit to finance their operations. Whereas, firm age and inventory have a positive and significant relationship with trade credit. This implies that older firms and firms with high inventory level use more trade credit as the financial source. This study does not find conclusive evidence to support that the profitability, assets structure, and sales growth influence the level of trade credit of manufacturing companies in Malaysia

Malaysia tourism demand forecasting using box-jenkins approach

Tourism industry in Malaysia is crucial and has contributes a huge part in Malaysia’s economic growth. The capability of forecasting field in tourism industry can assist people who work in tourism-related-business to make a correct judgment and plan future strategy by providing the accurate forecast values of the future tourism demand. Therefore, this research paper was focusing on tourism demand forecasting by applying Box-Jenkins approach on tourists arrival data in Malaysia from 1998 until 2017. This research paper also was aiming to produce the accurate forecast values. In order to achieve that, the error of forecast for each model from Box-Jenkins approach was measured and compared by using Akaike Information Criterion (AIC), Mean Absolute Deviation (MAD), Mean Square Error (MSE) and Mean Absolute Percentage Error (MAPE). Model that produced the lowest error was chosen to forecast Malaysia tourism demand data. Several candidate models have been proposed during analysis but the final model selected was SARIMA (1,1,1)(1,1,4)12. It is hoped that this research will be useful in forecasting field and tourism industry

Quality practices as a moderator in technology transfer performance

Absorptive capacity is one of the factors that determines the success of technology transfer. It improves one’s ability to assess the current and future needs of firms and leads them to make better choices. At the same time, quality movement in firms also has a similar vision; to make firms move forward in a competitive way. The objective of this paper is twofold. First, was to determine the association between absorptive capacity and technology transfer dimensions. Secondly, this study was conducted to determine the moderating role of firms’ quality practices in the relationship between firms’ absorptive capacity and technology transfer performance. Data was collected from Malaysian firms through mailed questionnaires. With a response rate of 32%, data was analyzed using multiple hierarchical regression and Chi Square method. The results showed quality process interacts significantly with knowledge diversification and transformative capacity during the integration stage. Moreover, the addition of a moderating variable increases the prediction of technology transfer performances. The result suggests firms’investment in quality practices improves the process of transferred technology