296 research outputs found
Analysis and Development of the Generic Maintenance Management Process Modeling for the Preservation of Heritage School Buildings
Preservation of heritage school buildings requires special maintenance management practices. A thorough understanding of the maintenance management process is essential in ensuring effective maintenance practices can be instituted. The aim of this paper was to develop a generic process model that will promote the understanding of an effective management of maintenance process for heritage school buildings. A process model for the Maintenance Management of Heritage School Buildings (MMHSB) was developed using the Integration Definition for Function Modeling (IDEF0) system through an iterative process. The initial MMHSB process model was submitted to a team of management experts from the Malaysian Ministry of Arts and Heritage and the Ministry of Education Malaysia for verifications. Based on their feedbacks the initial model was refined and a proposed model was developed. From the second verification, the feed back received formed the basis for the final model. The final model elucidates the items for the input, mechanism, control and output elements that are critical in the maintenance management of heritage school buildings. The model also redefines the existing scope of responsibilities of the Headmasters’ and Senior Assistants’ in the management of maintenance. The perceived effectiveness of the model by potential users was surveyed using a selected number of administrators from potentially recognized heritage schools. The results indicated that the process model is perceived as being helpful in clarifying the maintenance management process of heritage school buildings and is useful in changing the current reactive management practices to that of a more proactive practice. In conclusion, it is believed that the MMHSB Process Model is helpful in promoting the understanding of the maintenance management process which would lead to improve preservation practices of heritage school buildings
Finite Element Modelling of Creep Rupture on Grade 91 Steel using Monkman-Grant Ductility based Damage Model
Failure strain is a main parameter used in the ductility exhaustion based damage model in which the accuracy of the prediction is dependent on its input value. The experimental measured has indicated that the value of strain at fracture is extensively scattered, therefore may affect the prediction. This paper presents the result of creep rupture time using a modified creep damage model incorporating Monkman-Grant (MG) failure strain as an alternative to strain at fracture. Both strains at fracture and MG failure strain are separately employed in the damage model to predict the failure time of uniaxial smooth specimen and notched bar with different acuity ratios of 3.0 and 20. The FE model of the specimen is loaded under different stress values and the multiaxial failure strain at each stress level is estimated using Cock and Ashby void growth model. The predicted creep rupture time that is compared to the experimental data (in a range of 40-1000 hours) showing a good agreement within the scatter band of +/- factor of 2. Both approaches using strain at fracture and MG failure strain can be used in predicting the creep failure under uniaxial and multiaxial features. The advantage of using MG strain is that the laboratory creep testing can be interrupted prior to specimen fractured or once the secondary creep deformation occurs. Meanwhile, the determination of strain at fracture needs longer test duration where the test can be stopped only when the specimen broken
Revitalising critical components of urban decay features
Conservation and sustainability of historic cities in Malaysia have been drawing a lot attention from different stakeholders as many researches were undertaken relating heritage conservation and heritage tourism. The declaration of historic cities in Penang and Malacca as World Heritage Cities by UNESCO had proven that the conservation and preservation of tangible heritage assets not only essential to sustain the continuity of local cultural identity but also contribute to the economic regeneration and domestic heritage tourism. However, there have been only a small number of studies done on the urban decay features experienced by old towns in Malaysia and the corresponding revitalisation tools which suit the local culture context. Based upon the conflicts between urban decay issues arise within Ipoh Old Town and the lack of effective revitalisation efforts, the objectives are to identify the urban decay features currently experienced by Ipoh Old Town and to recommend the critical components to be revitalised in Ipoh Old Town. The mixed methods research which incorporated both quantitative and qualitative research approaches is adopted as the methodology for this study. The quantitative data is obtained through questionnaire surveys whereas the qualitative research methods involved the gathering of information through interviews and case study analysis. These suggestions are categories into three major themes which are revitalisation, stricter enforcement and financial funding
Determination of flow resistance coefficient for vegetation in open channel: laboratory study
This study focused on determination of flow resistances coefficient for grass in an open channel. Laboratory works were conducted to examine the effects of varying of roughness elements on the flume to determine flow resistance coefficient and also to determine the optimum flow resistance with five different flow rate, Q. Laboratory study with two type of vegetation which are Cow Grass and Pearl Grass were implementing to the bed of a flume. The roughness coefficient, n value is determine using Manning’s equation while Soil Conservation Services (SCS) method was used to determine the surface resistance. From the experiment, the flow resistance coefficient for Cow Grass in range 0.0008 - 0.0039 while Pearl Grass value for the flow resistance coefficient are in between 0.0013 - 0.0054. As a conclusion the vegetation roughness value in open channel are depends on density, distribution type of vegetation used and physical characteristic of the vegetation itsel
Current review towards the new best practices of Corporate Real Estate Management (CREM) in Malaysia
Corporate Real Estate (CRE) is referring to land and buildings owned by companies which are not primarily in the real estate business used for operational purpose. CRE covers the entire range of activities. Awareness of knowledge of CRE in Malaysia lacks because the researcher found that the operation of properties owned by a few large companies is undermanaged and underused. This review paper focuses on the definition of corporate real estate (CRE), components of CRE, and the current practice in the industry. This paper a desk analysis reviewing the literature on general management of the corporate real estate. By using the secondary data such as Company Annual Report, Previous studies and other relevant sources. There are several different issues to examine along the way, from the business strategies, Constituent and tools to help make the right decisions. It draws a framework for CRE analysis. From this paper, we can find the issue to improve the current practice on the CRE in Malaysia
Finite Element Modelling of Creep Rupture on Grade 91 Steel using Monkman-Grant Ductility based Damage Model
Failure strain is a main parameter used in the ductility exhaustion based damage model in which the accuracy of the prediction is dependent on its input value. The experimental measured has indicated that the value of strain at fracture is extensively scattered, therefore may affect the prediction. This paper presents the result of creep rupture time using a modified creep damage model incorporating Monkman-Grant (MG) failure strain as an alternative to strain at fracture. Both strains at fracture and MG failure strain are separately employed in the damage model to predict the failure time of uniaxial smooth specimen and notched bar with different acuity ratios of 3.0 and 20. The FE model of the specimen is loaded under different stress values and the multiaxial failure strain at each
stress level is estimated using Cock and Ashby void growth model. The predicted creep rupture time that is compared to the experimental data (in a range of 40-1000 hours) showing a good agreement within the scatter band of +/- factor of 2. Both approaches using strain at fracture and MG failure strain can be used in predicting the creep failure under uniaxial and multiaxial features. The advantage of using MG strain is that the laboratory creep testing can be interrupted prior to specimen fractured or once the secondary creep deformation occurs. Meanwhile, the determination of strain at fracture needs longer test duration where the test can be stopped only when the specimen broken
Corrosion Performance of Nanopaint for Automotive Application
Nanostructured coating that possessed high density of grain boundaries enable excellent physical coverage of the coated surface against corrosion and mechanical problems compared to the larger grain size of particles found in conventional paint. The current study focusses on the effect of SiO2 and TiO2 nanoparticles as additive in acrylic automotive paint for corrosion. The new paint namely nanopaints was prepared at three different concentrations. The nanopaint were characterized using Electro-chemical test and the open circuit potential (OCP) is recorded. Electrochemical test in a saltwater solution method also used to determine the potential of nanopaint concentration on automotive surfaces. The results reveal that nanoparticle additive provide better corrosion rate as compared to the original basecoat. The optimum anticorrosion behaviour for both TiO2 and SiO2 nanopaints were achieved at weight percentage of 1.5 wt% and 1.0 wt%, respectively. Therefore, the nanopaint has potential to provide better corrosion performance for automotive surface application
Reliability of graphene as charge storage layer in floating gate flash memory
This study aims to investigate the memory performances of graphene as a charge storage layer in the floating gate with difference doping concentration of n-channel and p-channel substrates using Silvaco ATLAS TCAD Tools. The simulation work has been done to determine the performance of flash memory in terms of memory window, P/E characteristics and data retention and have been validated with the experimental work done by other researchers. From the simulation data, the trend of memory window at low P/E voltage is nearly overlapped between simulation and experimental data. The memory window at ±20V P/E voltage for n-channel and p-channel flash memory cell are 15.4V and 15.6V respectively. The data retention for the n-channel flash memory cell is retained by 75% (from 15.4V to 11.6V) whereas for the p-channel flash memory cell is retained by 80% (from 15.6V to 12.5V) after 10 years of extrapolation with -1/1V gate stress which shows that p-channel flash memory cell demonstrates better data retention compared to n-channel flash memory cell
Optimization of warpage defect in injection moulding process using ABS material
Plastic injection moulding process produces various defects such as warpage, sink marks, weld lines and shrinkage. The purpose of present paper is to analyze the warpage defect on Acrylonitrile Butadiene Styrene (ABS) for selected part using FEA simulation. The approach was based on Taguchipsilas Method and Analysis of Variance (ANOVA) to optimize the processing parameters namely packing pressure, mould temperature, melt temperature and packing time for effective process. It was found that the optimum parameters for ABS material are packing pressure at 375 MPa, mould temperature at 40degC, melt temperature at 200degC and packing time at 1 s. Melt temperature was found to be the most significant factor followed by packing time and mould temperature. Meanwhile, packing pressure was insignificant factor contributing to the warpage in present study
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