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

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

Alkaline treatments on EFB fibre: the effect on mechanical-physical properties and fibre-cement hydration rate

The natural fibres commonly used to enhance the brittleness of the cement matrix but appropriate fibre should be used for a particular purpose depending upon the type of fibre and characteristics. The Oil Palm Empty Fruit Bunch (EFB) fibre is one of the major crops in Malaysia, which contribute large scale of waste that is durable and make it reasonable for utilization in cement-based product. However, the presence of hemicellulose, lignin and extractive (oil, sugar and starch) affect the performance of EFB fibre and causes an incompatibility of EFB fibre and cement. Hence, this research is been conducted to explore the suitable proportion of Sodium Hydroxide (NaOH) treatment for EFB fibre to increase the compatibility of cement with EFB fibre. The NaOH concentration of 0.2%, 0.4%, 0.6%, 0.8%, 1%, 2%, 3% and 4% were used in this study as a chemical pre-treatment of EFB fibre for surface morphology observation and hydration rate test. Meanwhile for only untreated fibre, fibre treated with 0.4% (low concentration), 1% (medium concentration) and 4% (high concentration) of alkali treatment were tested for tensile strength of single EFB fibre. The fibre treated with NaOH has shown a significant different on the hydration temperature for EFB fibre- cement mixed compared with the untreated fibre. The higher NaOH concentration, the greater hydration temperatures obtain. The Scanning Electron Microscopy (SEM) image show that the increment NaOH concentration applied, the rougher EFB fibre surface is observed with lesser silica body remain. The tensile properties of individual fibre treated with NaOH (0.4%, 1% and 4%) has shown significant increment as compare to the untreated fibre with the highest tensile properties mean value 422.90 N/mm2 at 4% NaOH concentration

A Review of application building information modeling (BIM) during pre-construction stage: retrospective and future directions

Pre-construction is one of the biggest areas of risk and uncertainty in construction project as it deals with subsurface ground conditions information. The amount of detail data needed in pre-construction especially for existing data modelling and site analysis should be sufficient enough to ensure that significant risks could not reasonably be anticipated. Current practicing method in interpreting data during this stage tasks reveal limitation. Construction industry faced many obstacles due to the depends on the traditional practice; paper-based document which missing and redundant data always happened. In recent years, there has been a shift in construction where people move to BIM application because of its potential to reduce the problem faced by infrastructure world. BIM has become a successful technology and widely popular in the construction world especially in developed countries because of its potential. Nowadays, people are moving one step ahead in BIM which is adoption of BIM during pre-construction stage. Thus, this paper review studies centered on BIM-integrated modelling during preconstruction stage. But there is lack of practical researches have been made during this stage. Although a large number of studies on BIM have been conducted in the past decade, a lack of consensus remains among researchers and practitioners regarding the applications of BIM during pre-construction stage, the availability of subsequent data integration tool for geotechnical activity. A comprehensive literature review was conducted for data collection and analysis. After in-depth review of journal articles widely cover the application of BIM, this study summarizes an overview and critical reflection of geotechnical data integration using BIM during pre-construction stage. The results are useful for the identification of research clusters and topics in the BIM community

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

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

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

Marshall properties of asphalt containing alternative fine aggregates under different ageing conditions

Fine aggregate is a main asphalt component, which provides essential effect on the performance of asphalt mixture. Major consumption of aggregate for construction has caused depletion of natural resources and needs for alternative aggregate. Industrial wastes generated from manufacturing processes were laboratory evaluated as alternative fine aggregates in hot mix asphalt with variation in hardness, density and water absorption. Detailed design of the asphalt containing the potential aggregates of garnet and coal bottom ash was prepared and compared with the conventional granite aggregate using Marshall mix design method. The asphalt mixtures were tested for volumetric properties and stability under different ageing conditions. Results showed that fine aggregate has considerably affected the asphalt properties. Garnet improves the asphalt density and stability compared with other fine aggregates under both ageing conditions, thereby suggesting the suitability of garnet as an aggregate in asphalt pavement

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

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

Thermal performance of single-story air-welled terraced house in malaysia: A field measurement approach

The provision requirement of 10% openings of the total floor area stated in the Uniform Building By-Law 1984 Malaysia is essential for natural lighting and ventilation purposes. However, focusing on natural ventilation, the effectiveness of thermal performance in landed residential buildings has never been empirically measured and proven, as most of the research emphasized simulation modeling lacking sufficient empirical validation. Therefore, this paper drawing on field measurement investigates natural ventilation performance in terraced housing with an air-well system. The key concern as to what extent the current air-well system serving as a ventilator is effective to provide better thermal performance is to be addressed. By adopting an existing single-story air-welled terrace house, indoor environmental conditions and thermal performance were monitored and measured using HOBO U12 air temperature and humidity, the HOBO U12 anemometer, and the Delta Ohm HD32.3 Wet Bulb Globe Temperature meter for a six-month duration. The results show that the air temperature of the air well ranged from 27.48?C to 30.92?C, with a mean relative humidity of 72.67% to 79.25%. The mean air temperature for a test room (single-sided ventilation room) ranged from 28.04?C to 30.92?C, with a relative humidity of 70.16% to 76.00%. These empirical findings are of importance, offering novel policy insights and suggestions. Since the minimum provision of 10% openings has been revealed to be less effective to provide desirable thermal performance and comfort, mandatory compliance with and the necessity of the bylaw requirement should be revisited

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

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

Coconut fibre and sawdust as green building materials: a laboratory assessment on physical and mechanical properties of particleboards

This paper evaluates, via a laboratory assessment, the physical properties (BS EN 323:1993, BS EN 324) and mechanical performance (BS EN 310: 1993) of hybrid particleboards using agricultural wastes, namely coconut fibre and sawdust. The process begins with the preparation of the materials where they are sieved and retained with the 5-mm sieve and then oven-dried. The hybrid particleboard mixed with the addition of resin (urea formaldehyde) was sprayed and hot pressed. The hot press temperature was set at 180◦ C, with the resin content of 8 wt.% and the design density of 650 kg/m3 used in producing the particleboard. The percentage/ratio of the composition of sawdust (SD) to coconut fibre (CF) varied ranging from 100SD:0CF to 70SD:30CF, 50SD:50CF, 30SD:70CF, and 0SD:100CF. Meanwhile, as for the thickness of the boards, it was categorised into three groups which are 16 mm, 20 mm, and 32 mm. The particleboards were conditioned to the room temperature for seven days before being tested for physical properties and mechanical performances. The results show that the most optimum composition of sawdust to coconut fibre is 0% sawdust to 100% coconut fibre (0SD: 100CF) and the optimum thickness is 20 mm, where its density is 761.99 kg/m3, swelling thickness is 11.98%, and water absorption at 37.64%. With the modulus of elasticity of 1510 N/mm2, the modulus of rupture of 17.8 N/mm2, and the internal bonding of 1.08 N/mm2, they satisfied the universal standard of Particleboard Type P3 of BS EN 312:2010