49 research outputs found

    Configuration of a newly optimized multi-cyclones unit as a fine particulate emission separator in air pollution control

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    Multi-cyclones separator, which consists of many miniature cyclones, works in the same principle as single cyclone in separation of particulate matter from flue gas. However, multi-cyclone is able to attain higher collection efficiency and concurrently avoid rapid increasing of pressure drop due to the usage of small diameter cyclone. The studies on multi-cyclones are very limited and lacking especially on its design configurations due to its confidentiality and commercial reason. Thus, a configuration of a newly optimized multi-cyclone unit named as MR-deDuster is discussed and assessed in this study. Six dimensions considered in the study include diameter of cyclone (D), diameter of vortex finder (De), length of cyclone body (Lb), length of cyclone cone (Lc), length of vortex finder (S), and diameter of dust outlet (Dd). The theoretical background of the unit was developed based on the modifications of established design equations available in literatures. The selection of the new dimension and the actual size of the unit were based on two main criteria (the performance of the unit based on its cut-diameter and the ratio of axial dimensions). The predicted cut-diameter and pressure drop of the selected dimension was 1.7 μm and 86 mm of water, respectively. Meanwhile, the optimum axial ratios of the final design were Lb/D = 1.6, S/D = 1, and Lb-S/D = 0.7, with respect to the diameter of the cyclone

    Resource-based view in construction project management research: A meta-analysis

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    Resource-based view (RBV) is the theory that has been adopted as the theoretical background in construction project management (CPM) research to examine the impact of resources and capabilities on firm performance. Its primary assumption is that firms' performance and competitive advantages are enhanced by properly utilising valuable resources and capabilities. This paper aims to examine the effect of various constructs and relations used in preceding research by proposing a conceptual framework in the lens of RBV, which combined the multiple paths found in the literature. Then, hypotheses were developed to test the research framework empirically. This paper reports a meta-analysis of 20 journal papers published in the Scopus database in the area of CPM. The findings indicate that all the relationships between resources, capabilities, competitive advantage and performance were verified as significant. Moreover, the review pointed out that using capabilities and sustained competitive advantage in a mediated model is better than the direct effect model. Finally, a flowchart combining all the variables, construct, and paths was developed based on the results

    Multi-criteria decision analysis for evaluating sustainable lifts design of public hospital buildings

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    Sustainability is a big trend in today's building industry. For instance, energy use, resource efficiency, materials selection, safety, and life-cycle management are all important considerations in making the transition to greener buildings. In the past, lifts have been overlooked in green building planning yet including them is a useful way to improve overall building functionality and efficiency. Lifts use a relatively small amount of energy compared to the overall energy consumption of a building yet they provide both daily carrier service for user and so they should be included in sustainability planning. With so many building products being marketed with a sustainable angle, lifts also need to be included in this improvement. Building process has become complex due to the involvement of multiple benchmark like social, economic and environmental dimensions. A significant challenge for those involved in the building industry is identifying and incorporating sustainable features into each of the building stage. This in turn puts constrains to decision makers in selecting the finest decision in achieving sustainable goal for every aspect of building processes. This paper investigates the multi-criteria decision analysis for sustainable lifts design, namely; criteria selection, criteria weighting, evaluation and final aggregation. Decision analysis plays a vital role for designing the systems by considering various criteria. The criteria were grouped based on economic, environmental and social dimensions. Technique for order preference by similarity to ideal solution (TOPSIS) methods were employed to rank the most important criteria that need to be considered in making the decision. A design team from hospital project specifically from mechanical and electrical department have been chosen for this study due to their expertise in planning and designing the mechanical aspects for a project. As a result, it shows the process of decision analysis and provides the direction for sustainable lifts criteria selection which has a significant effect on the design. The result shows the preference dimension for sustainable lift design is economic aspect including its criteria required as decision analysis output for planning and designing lifts systems for public hospital buildings

    Issues and challenges of joint management body in high-rise residential facilities management: the developers

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    High demand for housing and land scarcity in the town area has increased the provision of High-rise Residential Buildings (HrRB). HrRB has different owners but shares the same land and common facilities. Its common facilities are generally prone to damages either from “wear and tear” or vandalism. Therefore, Thus, maintenance works of HrRB and its common facilities should be done properly and periodically by experienced property management company. By the introduction of new laws and implementation thereof, Joint Management Body (JMB) was established to govern the rights and obligations of three parties’ i.e., purchasers, developer, and facilities manager. The residents constantly point fingers to property management if there is dissatisfaction on the damage restoration and maintenance work done. In fact, strata management issues were brought to court by owners for adjudication, such as ACN Infra Sdn Bhd v Perbadanan Pengurusan Kondominium Subang Indera [2020] 3 AMR 741, duties of management corporation in repairing defects were debated. In another case of Muhamad Nazri Muhamad v. JMB Menara Rajawali & Anor Civil Appeal No: W-02(NCVC)(A)-205710/2018, owners disputed whether the management body could charge a different rate of maintenance charges for different properties in HrRB. Hence, this paper intends to address the issues and challenges related to property management. This research is based on a questionnaire survey from the developer’s perspective. An Average Index analysis was used to rank the level of significance issues, challenges, and major roles of JMB. The key roles of developers in JMB under Strata Property Management were highlighted in order to ensure the common facilities for HrRB more manageable in its damage recovery

    The impact of air well geometry in a Malaysian single storey terraced house

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    In Malaysia, terraced housing hardly provides thermal comfort to the occupants. More often than not, mechanical cooling, which is an energy consuming component, contributes to outdoor heat dissipation that leads to an urban heat island effect. Alternatively, encouraging natural ventilation can eliminate heat from the indoor environment. Unfortunately, with static outdoor air conditioning and lack of windows in terraced houses, the conventional ventilation technique does not work well, even for houses with an air well. Hence, this research investigated ways to maximize natural ventilation in terraced housing by exploring the air well configurations. By adopting an existing single storey terraced house with an air well, located in Kuching, Sarawak, the existing indoor environmental conditions and thermal performance were investigated and monitored using scientific equipment, namely HOBO U12 air temperature and air humidity, the HOBO U12 anemometer and the Delta Ohm HD32.3Wet Bulb Globe Temperature meter. For this parametric study, the DesignBuilder software was utilized. The field study illustrated that there is a need to improve indoor thermal comfort. Thus, the study further proposes improvement strategies to the existing case study house. The proposition was to turn the existing air well into a solar chimney taking into account advantages of constant and available solar radiation for stack ventilation. The results suggest that the enhanced air well was able to improve the indoor room air velocity and reduce air temperature. The enhanced air well with 3.5 m height, 1.0 m air gap width, 2.0 m length was able to induce higher air velocity. During the highest air temperature hour, the indoor air velocity in existing test room increased from 0.02 m/s in the existing condition to 0.29 m/s in the hottest day with 2.06 °C air temperature reduction. The findings revealed that the proposed air well could enhance the thermal and ventilation performance under the Malaysia tropical climate

    Review of Big Data integration in construction industry digitalization

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    The 2030 agenda for sustainable development has embraced the importance of sustainable practices in the construction industry. Parallel to the Industry revolution 4.0, the construction industry needs to keep pace with technological advances in data management to keep pace with the revolution through the ability to process and extract value from data. This phenomenon attracts the requirement of Big Data (BD). The construction industry deals with large volumes of heterogeneous data, which is expected to increase exponentially following an intense use of modern technologies. This research presents a comprehensive study of the literature, investigating the potential application of BD integration in the construction industry. The adoption of such technologies in this industry remains at a nascent stage and lags broad uptake of these technologies in other fields. The Construction Industry is driving to boost its productivity through the implementation of data technologies, hence, significant research is needed in this area. Currently, there is a lack of deep comprehensive research on BD integration applications that provide insight for the construction industry. This research closes the gap and gives an overview of the literature. The discussion presented the current utilization, the issues, and ways for potential works along with the challenges companion with the implementation

    Time-lag analysis of potential waste materials as thermal insulation in tropical climate: A preliminary investigation

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    Energy consumption has shown that residential building is among the main contributors of energy demand. Besides, the harsh climatic conditions have causes substantial amount of energy which contributes indirectly towards the impact on carbon emission to the nations. Hence, this research utilised the potential agricultural wastes materials that is potential for insulate the thermal building performance. The outer and inner surface temperature has been measured on selected seven (7) type of wastes material from agricultural and processing sector every 30 minutes from 0900hr to 1800hr for a day in order to determine the decrement factors (DF), average daily time-lag for heat transfer as one of the thermal insulation properties. Results on the time-lag for all selected potential waste materials as thermal insulation whereas sugarcane bagasse is the lowest 107.5 minutes, followed by both coffee grounds and coconut husk with 130 minutes and wood wool with 132.5 minutes. Meanwhile, empty fruit bunch, coconut fibre and pineapple leave with time-lag of 140 minutes, 142.5 minutes and 145 minutes respectively are the highest time-lag occurred. Generally, the lowest Tis is the better the thermal performance therefore, coconut fibre with smaller DF, larger LT but slightly higher Tis than EFB (32°C) which is 32.2 °C might be the suitable material use as thermal insulation
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