This review provides a comprehensive overview of natural rubber(NR)composites,focusing on their properties,compounding aspects,and renewable practices involving natural fibre reinforcement.The properties of NR are inf...This review provides a comprehensive overview of natural rubber(NR)composites,focusing on their properties,compounding aspects,and renewable practices involving natural fibre reinforcement.The properties of NR are influenced by the compounding process,which incorporates ingredients such as elastomers,vulcanizing agents,accelerators,activators,and fillers like carbon black and silica.While effective in enhancing properties,these fillers lack biodegradability,prompting the exploration of sustainable alternatives.The potential of natural fibres as renewable reinforcements in NR composites is thoroughly covered in this review,highlighting both their advan-tages,such as improved sustainability,and the challenges they present,such as compatibility with the rubber matrix.Surface treatment methods,including alkali and silane treatments,are also discussed as solutions to improve fibre-matrix adhesion and mitigate these challenges.Additionally,the review highlights the potential of oil palm empty fruit bunch(EFB)fibres as a natural fibre reinforcement.The abundance of EFB fibres and their alignment with sustainable practices make them promising substitutes for conventional fillers,contributing to valuable knowledge and supporting the broader move towards renewable reinforcement to improve sustain-ability without compromising the key properties of rubber composites.展开更多
A clean environment with low carbon emissions is the goal of research on the development of green and sustainable buildings that use bio-sourced materials in conjunction with solar energy to create more sustainable ci...A clean environment with low carbon emissions is the goal of research on the development of green and sustainable buildings that use bio-sourced materials in conjunction with solar energy to create more sustainable cities.This is particularly true in Africa,where there aren’t many studies on the topic.The current study suggests a 90 m^(2) model of a sustainable building in a dry climate that is movable to address the issue of housing in remote areas,ensures comfort in harsh weather conditions,uses solar renewable resources—which are plentiful in Africa—uses biosourced materials,and examines how these materials relate to temperature and humidity control while emitting minimal carbon emissions.In order to solve the topic under consideration,the work is split into two sections:numerical and experimental approaches.Using TRNSYS and Revit,the suggested prototype building is examined numerically to examine the impact of orientation,envelope composition made of bio-sourced materials,and carbon emissions.Through a hygrothermal investigation,experiments are conducted to evaluate this prototype’s effectiveness.Furthermore,an examination of the photovoltaic system’s production,consumption,and several scenarios used tomaximize battery life is included in the paper.Because the biosourcedmaterial achieves a thermal transmittance of 0.15(W.m^(-2).K^(-1)),the results demonstrate an intriguing finding in terms of comfort.This value satisfies the requirements of passive building,energy autonomy of the dwelling,and injection in-network with an annual value of 15,757 kWh.Additionally,compared to the literature,the heating needs ratio is 6.38(kWh/m^(2).an)and the cooling needs ratio is 49(kWh/m^(2).an),both of which are good values.According to international norms,the inside temperature doesn’t go above 26℃,and the humidity level is within a comfortable range.展开更多
Multicriteria Decision Analysis(MCDA)has been integrated with GIS modelling by many studies to aid the decision-making process.This integration enhances modelling by incorporating spatial relationships and using advan...Multicriteria Decision Analysis(MCDA)has been integrated with GIS modelling by many studies to aid the decision-making process.This integration enhances modelling by incorporating spatial relationships and using advanced techniques,including the combination of Frequency Ratio(FR)and Analytical Hierarchical Process(AHP),also known as FR-AHP.Although methods like Two-Steps Floating Catchment Area(2SFCA),AHP,and FR are widely applied in measuring accessibility,they have limitations in terms of threshold sensitivity and subjectivity.Hence,this study used FR-AHP,which combines the data-driven strength of FR and the structured decision-making technique of AHP to provide a more reliable evaluation of spatial accessibility.This study aims to integrate FR-AHP with GIS to derive campus spatial accessibility in Shah Alam.Campus spatial accessibility can be measured by using location and distance between origin and destination,topological accessibility for nodes and paths,and contiguous accessibility for surfaces.Understanding these concepts is crucial for determining the appropriate technique.This study utilizedMCDA,GIS-basedFR,andAHPmethods tomodel spatial accessibility in activemobility andpublic transport areas,calculating estimation index values and analyzing comparisons between physical factors.A sample survey was conducted among the university’s students to gather information on their origin and destination,as well as the type of transportation used by students.The data were used in calculating the weightage of each physical factor using the FR-AHP method.Then,the Campus Spatial Accessibility Index(CSAI)was determined by using GIS IndexModelling.By using the model,the index was classified into five(5)classes from Very Low to Very High.The results show that Section 2 has the highest accessibility,while the area with the lowest accessibility index is Jalan Zamrud and Jalan Permata,located in Section 7.To analyze the efficiency of FR-AHP,the CSAI was also derived using theweightage derived fromFR only.The comparisons revealed that the results derived using FR-AHP are closer to reality than those derived using FR only,as it incorporates human preferences in accessibility.Hence,the findings suggest that the integration of FR-AHP could provide better CSAI than FR only.展开更多
Ground Penetrating Radar(GPR)is a widely used method that is non-destructive for underground or subsurface detection.It is used in various fields and has proved to be reliable and effective.This research focuses on de...Ground Penetrating Radar(GPR)is a widely used method that is non-destructive for underground or subsurface detection.It is used in various fields and has proved to be reliable and effective.This research focuses on detecting the presence of air cavities using GPR and analyzing the radargram output based on the compactness of soil and different frequencies.The compactness is used to illustrate the presence of cavities underground artificially.The research examines how variations in the compactness of soil affect the radargram response in showing the presence of cavities using different frequencies.Experimental results demonstrate that lower permittivity materials enhance signal penetration but reduce reflection contrast,whereas higher permittivity materials result in stronger reflections,improving cavity detection.The findings highlight the importance of frequency selection and material properties in optimizing GPR surveys for subsurface anomaly detection,and by having artificially created cavities,the results can be studied to see the changes.展开更多
The integration of Unmanned Aerial Vehicles(UAVs)and Uncrewed Surface Vehicles(USVs)has revolutionized topographic and bathymetricmapping,significantly enhancing the accuracy and efficiency of geospatial data acquisit...The integration of Unmanned Aerial Vehicles(UAVs)and Uncrewed Surface Vehicles(USVs)has revolutionized topographic and bathymetricmapping,significantly enhancing the accuracy and efficiency of geospatial data acquisition processes.This innovative approach synergistically combines terrestrial data collected by UAVs with underwater data obtained through USVs,culminating in the creation of unified high-resolution Digital Elevation Models(DEMs)of the river basin region represents a vital step toward understanding the dynamic interactions between land and water bodies.Hence,the seamless Topo-Bathymetric Elevation Model offers a detailed perspective of the river system,supporting informed decision-making in addressing sediment transport,erosion,and river morphology.This manuscript provides a comprehensive review examines the advanced methodologies for creating seamlessmultisource Topo-Bathymetry ElevationModels(TBEMs)in river basin contexts,emphasising critical factors such as cost-effectiveness,operational efficiency,and data precision.In particular,UAVs deliver high-resolution(1-3 cm)topographic mapping with 5-10 km operational ranges,while USVs provide complementary bathymetric data(1 m resolution)across 3-5 km.This synergy enables seamless land-water surveys,achieving superior precision(±8 cmterrestrial,±3 cmunderwater)and efficiency over traditional methods.By analysing the benefits and limitations inherent in these technologies,this review elucidates the potential of UAV-USV synergy to improve the accuracy and reliability of geospatial data,thereby supporting well-versed decision-making processes in environmental management and conservation efforts.Furthermore,the findings underscore the broader implications of this integrated approach for riverine and coastal studies,advocating for its wider adoption in various applications,including habitat monitoring,flood risk assessment,and sustainable resource management.The synthesis of terrestrial and aquatic data through UAV-USV collaboration not only advances the field of geospatial science but also fosters a deeper understanding of the interdependencies between land and water systems,ultimately contributing to more effective environmental stewardship.展开更多
Single-beam echo sounders remain popular for seabed mapping because they possess an affordable cost and user-friendly design,delivering essential services for marine navigation,coastal management and resource conserva...Single-beam echo sounders remain popular for seabed mapping because they possess an affordable cost and user-friendly design,delivering essential services for marine navigation,coastal management and resource conservation.High-amplitude echoes known as sea-spikes can severely harm depth measurement precision by disrupting readings,thus lowering the overall data accuracy.The manual processing method for outliers produces subjective results and demands excessive labor,which makes it difficult to accomplish trustworthy data processing.The study presents the Sea-Spike Filtering System(SSFS)as a semi-automatic system that utilizes mean absolute deviation(MAD)together with median filter(MF)techniques to efficiently find and eliminate false data in sea observations.The SSFS system showed reliable noise reduction abilities when tested with actual bathymetric data from Bintulu,Sarawak,thus delivering data quality upgrades that fulfilled 59.39%of International Hydrographic Organization(IHO)Order 2 Total Vertical Uncertainty(TVU)guidelines.The Mean Absolute Deviation value decreased substantially from 1.0618 to 0.4314,which enhanced noise reduction without influencing the Residual Mean Square Error or Mean Absolute Error statistics of 1.4188 and 0.9663m,respectively.Thesuccessful elimination of sea-spike outliers through the systemleads to general-purpose survey accuracy,yet more system improvements are required to meet the demanding safety standards in shallow water applications.展开更多
Digital ElevationModel(DEM)refers to a digital map of the surface of the Earth that only shows the bare ground,without any buildings,plants,or other characteristics.However,obtaining unlimited access to DEM data at hi...Digital ElevationModel(DEM)refers to a digital map of the surface of the Earth that only shows the bare ground,without any buildings,plants,or other characteristics.However,obtaining unlimited access to DEM data at high and medium resolutions is very hard.Consequently,users often question the accuracy of freely available DEMs and their suitability for various applications.By comparing them to Global Positioning System(GPS)elevation data,this study aimed to identify themost reliable and widely available DEM for various terrains.The objectives of this study were to generate DEMs fromdifferent open sources and validate the accuracy of these DEMs using GPS elevation data.Various DEM types including Sentinel-1,ALOS PALSAR,SRTM,AW3D30,and ASTER were compared.Root Mean Square Error(RMSE)andMean Error(ME)were used to measure the difference between the DEM-derived elevations and the GPS-measured elevations.The results showed that even though Sentinel-1 has higher resolutions,the accuracy of the DEM from Sentinel-1 depends on issues including coherence and interferometry,surface features,and temporal stability.On the other hand,ALOS PALSAR could accurately represent surfaces in some situations.Additionally,DEMs with lower resolutions,such as SRTM and AW3D30,demonstrated greater consistency across various types of terrain.In contrast,the ASTER DEM showed more variability in complex terrains.While freely available DEMs are easy to use and accessible,their accuracy varies depending on the source and terrain features.Future improvements could include adding more ground control points and using advanced filtering methods to enhance precision.展开更多
Cement-based materials (CBMs),such as paste,mortar and concrete,are highly alkaline with an initial high pH of approximately 12.0 to 13.8.CBMs have a high pH due to the existing oxide mineral portlandite and alkali me...Cement-based materials (CBMs),such as paste,mortar and concrete,are highly alkaline with an initial high pH of approximately 12.0 to 13.8.CBMs have a high pH due to the existing oxide mineral portlandite and alkali metal contents in Portland cement.The high pH of concrete provides excellent protection and reinforces the steel bars against corrosion.The pH of concrete does not remain constant due to ageing and other defect-causing factors,such as chloride ingress,alkali leaching,carbonation,corrosion,acid attack,moisture and biodegradation process.Reducing the concrete pH has negative impact on the strength,durability and service life of concrete buildings.However,the high pH of concrete may also cause concrete structure deterioration,such as alkali silica reaction,porosity and moisture related damages in concrete structures.The pH of CBMs can be influenced by high temperatures.For instance,the extremely high volume (85%-100%) of slag-blended cement pastes shows considerable pH reduction from 12.80 to 11.34 at 800 ℃.As many concrete structure deterioration are related to concrete pH,using an accurate and reliable method to measure pH and analyse the durability of reinforced concrete structure based on pH values is extremely important.This study is a comprehensive review of the pH of CBM in terms of measurement,limitations and varying values for different CBM types.展开更多
The purpose of this work was to explore the influence law of vibration load on rock mass structure and slope stability.Based on the type and transmission way of vibration stress wave,the main stress in the horizontal ...The purpose of this work was to explore the influence law of vibration load on rock mass structure and slope stability.Based on the type and transmission way of vibration stress wave,the main stress in the horizontal and vertical directions was analyzed and the superposition effect of the stress wave was revealed.After the mechanical analysis of the sliding mass,the calculation formulas of the anti-sliding force and the sliding force were derived and the damage mechanism of blasting vibration to the structural plane was defined.In addition,according to the structure and lithologic parameter of the slope as well as the vibration monitoring data,the west slope stability of Xiaolongtan open pit mine was analyzed.The results show that the time-dependent stability factor is proportional to the vibration speed and the peak values appear at the same time.Vibration load promotes the breakage of the structural plane leading to the drop of the west slope stability factor by 0.23%.Under the multipoint simultaneous blasting,the fluctuating laws of the stability factors are consistent.The more the start-up points are,the higher the weakening degree to the slope stability is.Under the multipoint allochronic blasting,the stability factor depends on the synthetic waveform structure of all vibration waves.The greater the blasting time difference is,the lower the weakening degree to the slope stability is.Selecting the reasonable quantity of start-up points and time difference could fully reduce the adverse influence of vibration load to slope stability.展开更多
A quantitative pH measuring method has been used to measure the pH of pure and blended cement mortars.The blended cement mortars incorporating supplementary cementitious materials(SCMs)such as fly ash(FA),ground granu...A quantitative pH measuring method has been used to measure the pH of pure and blended cement mortars.The blended cement mortars incorporating supplementary cementitious materials(SCMs)such as fly ash(FA),ground granulated ballast furnace slag(GGBFS)and palm oil fuel ash(POFA)were used.Moreover,different variables affecting the pH values of CBMs such as temperature of sample solution,quantity of sample powder,dilution ratio and temporary storage of sample during pH measuring process have been studied for all cement mortars.展开更多
This paper studies the dynamic stress intensity factor （DSIF） at the interface in an adhesive joint under shear loading. Material damage is considered. By introducing the dislocation density function and using the i...This paper studies the dynamic stress intensity factor （DSIF） at the interface in an adhesive joint under shear loading. Material damage is considered. By introducing the dislocation density function and using the integral transform, the problem is reduced to algebraic equations and can be solved with the collocation dots method in the Laplace domain. Time response of DSIF is calculated with the inverse Laplace integral transform. The results show that the mode Ⅱ DSIF increases with the shear relaxation parameter, shear module and Poisson ratio, while decreases with the swell relaxation parameter. Damage shielding only occurs at the initial stage of crack propagation. The singular index of crack tip is -0.5 and independent on the material parameters, damage conditions of materials, and time. The oscillatory index is controlled by viscoelastic material parameters.展开更多
This paper will discuss the computerised developm en t control and approval system being developed for the Planning and Development C ontrol Department, City Hall of Kuala Lumpur, with stress on the GIS architectur e ...This paper will discuss the computerised developm en t control and approval system being developed for the Planning and Development C ontrol Department, City Hall of Kuala Lumpur, with stress on the GIS architectur e developed within the system. The prospects and challenges towards implementati on of the system are also discussed.展开更多
Different modification methods and software programs were developed to obtain accurate local geoid models in the past two decades.The quantitative effect of the main factors on the accuracy of local geoid modeling is ...Different modification methods and software programs were developed to obtain accurate local geoid models in the past two decades.The quantitative effect of the main factors on the accuracy of local geoid modeling is still ambiguous and has not been clearly diagnosed yet.This study presents efforts to find the most influential factors on the accuracy of the local geoid model,as well as the amount of each factor’s effect quantitatively.The methodology covers extracting the quantitative characteristics of 16 articles regarding local geoid models of different countries.The Statistical Package of Social Sciences(SPSS)software formulated a strong multiple regression model of correlation coefficient r = 0.999 with a high significance coefficient of determination R^2 = 0.997 and adjusted R^2 = 0,98 for the required effective factors.Then,factor analysis is utilized to extract the dominant factors which include:accuracy of gravity data(40%),the density of gravity data(25%)(total gravity factors is 65%),the Digital Elevation Model(DEM)resolution(16%),the accuracy of GPS/leveling points(10%)and the area of the terrain of the country/state under the study(9%).These results of this study will assist in developing more accurate local geoid models.展开更多
The purpose and context for the study relates to urban growth. Australian cities are experiencing particularly rapid urbanization, taking the form of land clearing to accommodate outward expansion as well as developin...The purpose and context for the study relates to urban growth. Australian cities are experiencing particularly rapid urbanization, taking the form of land clearing to accommodate outward expansion as well as developing to higher densities in existing urban areas. Both forms of development degrade native biodiversity, resulting in loss of vegetation with the possibility that the remnant indigenous plants will become locally extinct. One endangered ecological community in Sydney, the Eastern Suburbs Banksia Scrub (ESBS), still survives along some sections of Sydney’s heavily urbanized coastline. At the time of European settlement, the ESBS covered approximately 5300 ha, but it is now a highly fragmented 146 ha across 24 sites with some sites under imminent threat of development. Conservation legislation enacted by the state of New South Wales (NSW), Australia has declared the ESBS as critically endangered. Despite recovery plans, in 2016 the NSW Threatened Species Scientific Committee indicated that the community faces an extremely high risk of extinction in Australia in the immediate future. A practical option in the face of declining open space in our cities is to examine the potential of urban rooftops for conserving and propagating threatened or endangered flora. While there is a limited amount of international research on using green roofs for endangered plant protection, there is no information from Australia about how green roofs perform in this geographic region. The approach taken in this research has been firstly, to review the current academic and “grey” literature from a global perspective to identify options for conserving endangered flora on green roofs. We derive an evidence-based research protocol to be used to test the green roof environment in Sydney for propagating the endangered ESBS. We establish the general applicability of green roofs for protecting vanishing flora through the literature review and conclude that our research design will be a suitable framework for the task for monitoring growth and germination performance over the ESBS community’s development cycle, with the longer-term objective of establishing a viable rooftop seed orchard.展开更多
This study investigates the influence of using ground palm oil fuel ash(G-POFA) from 10%-30% as cement replacement(by weight) on the cement mortar's pH under various curing conditions. These findings were suppleme...This study investigates the influence of using ground palm oil fuel ash(G-POFA) from 10%-30% as cement replacement(by weight) on the cement mortar's pH under various curing conditions. These findings were supplemented by thermal gravimetric analysis(TGA). Moreover, the resistance of G-POFA blended cement mortars to water absorption and sorptivity was determined. Further, the k-value test was carried out to explain the pozzolanic and filler behavior of G-POFA and to support the results obtained from TGA. It was found that there was no significant impact of several curing conditions on the pH of mortars. The mortar with 10% G-POFA in replacement of cement(G-POFA-10) exhibited the best resistance against water absorption and sorptivity.展开更多
The purpose of this paper is to implement and validate a decision making framework for building maintenance projects. The growing importance of maintenance sector not only in Malaysia but al- so increasingly globalize...The purpose of this paper is to implement and validate a decision making framework for building maintenance projects. The growing importance of maintenance sector not only in Malaysia but al- so increasingly globalized, the difficulty in selecting an appropriate procurement method and lack of research in this area provide an impetus for this research. There were 19 procurement selection criteria identified. In addition, there were 4 types of procurements methods which include outsourcing by specialist term contract, outsourcing by tendered schedule term contract, out- sourcing by repair and maintenance contract and outsourcing by measured term contract identified to be the most popular procurement methods adapted by public universities currently and at the same time were considered most important. The decision making framework was developed based on AHP technique and principles. Expert Choice Software was employed as development tool where the criteria and alternatives were integrated into the framework. Finally, structured interview was conducted to validate the framework developed. The validation process was carried out through structured interview with selected public university.展开更多
Optimizing the combined horizontal and vertical accuracy of the well-known Global Digital Elevation Models(GDEMs) of various resolutions for each country and region especially in Iraq’s mountainous areas is still que...Optimizing the combined horizontal and vertical accuracy of the well-known Global Digital Elevation Models(GDEMs) of various resolutions for each country and region especially in Iraq’s mountainous areas is still questionable. All the three GDEMs, approximately, have the same vertical accuracy with the Root Mean Square(RMSE) of ±7.3 m, ±7.6 m and ±6.5 m via 12 fixed Ground Control Points(GCPs) for the Advanced Land Observation Satellite Phased Array L-band Synthetic Aperture Radar(ALOS PALSAR 12.5 m), the Shuttle Radar Topographic Mission(SRTM 30 m) and the TerraSAR-X(the name of twin satellites) add-on for Digital Elevation Measurement(TanDEM-X 90 m) GDEMs respectively. Moreover, the percentage of outliers that are greater or smaller than ±10 m detection of the height extraction from both the ALOS PALSAR and SRTM Digital Elevation Models(DEMs) contains 16.7% and for TanDEM-X was 25%. In this paper,the special DEM is derived using 2123 handheld GPS points for Sulaymaniyah Governorate, Kurdistan region, Iraq. The height extraction by discarding the outliers of 58% gives the RMSE of ±8.0 m in the case of adding geoid heights(N) to the ellipsoidal heights(h) via the Earth Gravitational Model 2008(EGM2008)and ±5.6 m without adding N. It is expected that the derived DEMs will give more accurate results both horizontally and vertically in the mountainous areas when GPS observations are intensified. The horizontal accuracy is validated through extracting hierarchy stream types of the watershed map from the DEMs for higher than 100 pixels length. The ALOS PALSAR DEM extracted more numbers of stream orders than others.Finally, based on the criteria of RMSE, outlier detection, and the number of extracted stream orders, the ALOS PALSER DEM is regarded as the optimal GDEM in comparison with the close accuracy of both the TanDEM-X and SRTM DEM.展开更多
Lack of preventive measure is currently the problem that implicates poor building maintenance performance and issue on sustainability of buildings in Malaysia. Whereby, preventive maintenance is an effective approach ...Lack of preventive measure is currently the problem that implicates poor building maintenance performance and issue on sustainability of buildings in Malaysia. Whereby, preventive maintenance is an effective approach to enhance the reliability and quality of a system and its components. This study seeks to investigate the characteristics of preventive maintenance towards the overall performance in building maintenance. Case study approach is adopted to identify the maintenance characteristics and aspects that lead to good performance. The research findings demonstrate that the most significant maintenance characteristics towards overall performance are skill and knowledge of maintenance labour, quality of spare parts and materials, length of predetermined maintenance interval, skill and knowledge of maintenance manager, capability to adopt maintenance equipment and technique, budget allocation for acquisition of maintenance data, reliability of maintenance data, as well as frequency of monitoring and inspection. As a conclusion, the significant maintenance characteristics must be taken into consideration to achieve optimal maintenance performance. In order to improve the effectiveness of maintenance strategy and the maintenance performance, the study recommends practice and provision of communication platform such as meeting and customer satisfaction survey that involves all the key participants from clients to customers.展开更多
The increasing of development failure on highland urges the professionals to develop solution on mitigating the problems. This paper discusses on land development process and legislation on highland development in Mal...The increasing of development failure on highland urges the professionals to develop solution on mitigating the problems. This paper discusses on land development process and legislation on highland development in Malaysia and Hong Kong. This study is focus on land use planning, laws and regulations pertaining to land development process. Hence, this research is to review the current development process including mechanism and legislation pertaining land development on highland in Malaysia and Hong Kong. Hong Kong is chosen as an example based on the fact that for its successfulness in managing highland developments. The main aim of this research is to evaluate the effectiveness of land development legislations and development approaches for highland development. This research reveals the effects and consequences of implementation regulations and development process on highland that have been used at Malaysia and Hong Kong. In Malaysia, land development process on highland is still in questionable;why present property laws and regulations are fail to achieve highland development standards as compared to Hong Kong. There are weaknesses that need to be overcome such as on the implementation and the intensity of the provision in property laws and regulation that can ensure the achievement of required land development process.展开更多
基金funded under the Collaborative Research Initiative Grant Scheme(C-RIGS),grant number C-RIGS24-016-0022 from IIUM.
文摘This review provides a comprehensive overview of natural rubber(NR)composites,focusing on their properties,compounding aspects,and renewable practices involving natural fibre reinforcement.The properties of NR are influenced by the compounding process,which incorporates ingredients such as elastomers,vulcanizing agents,accelerators,activators,and fillers like carbon black and silica.While effective in enhancing properties,these fillers lack biodegradability,prompting the exploration of sustainable alternatives.The potential of natural fibres as renewable reinforcements in NR composites is thoroughly covered in this review,highlighting both their advan-tages,such as improved sustainability,and the challenges they present,such as compatibility with the rubber matrix.Surface treatment methods,including alkali and silane treatments,are also discussed as solutions to improve fibre-matrix adhesion and mitigate these challenges.Additionally,the review highlights the potential of oil palm empty fruit bunch(EFB)fibres as a natural fibre reinforcement.The abundance of EFB fibres and their alignment with sustainable practices make them promising substitutes for conventional fillers,contributing to valuable knowledge and supporting the broader move towards renewable reinforcement to improve sustain-ability without compromising the key properties of rubber composites.
文摘A clean environment with low carbon emissions is the goal of research on the development of green and sustainable buildings that use bio-sourced materials in conjunction with solar energy to create more sustainable cities.This is particularly true in Africa,where there aren’t many studies on the topic.The current study suggests a 90 m^(2) model of a sustainable building in a dry climate that is movable to address the issue of housing in remote areas,ensures comfort in harsh weather conditions,uses solar renewable resources—which are plentiful in Africa—uses biosourced materials,and examines how these materials relate to temperature and humidity control while emitting minimal carbon emissions.In order to solve the topic under consideration,the work is split into two sections:numerical and experimental approaches.Using TRNSYS and Revit,the suggested prototype building is examined numerically to examine the impact of orientation,envelope composition made of bio-sourced materials,and carbon emissions.Through a hygrothermal investigation,experiments are conducted to evaluate this prototype’s effectiveness.Furthermore,an examination of the photovoltaic system’s production,consumption,and several scenarios used tomaximize battery life is included in the paper.Because the biosourcedmaterial achieves a thermal transmittance of 0.15(W.m^(-2).K^(-1)),the results demonstrate an intriguing finding in terms of comfort.This value satisfies the requirements of passive building,energy autonomy of the dwelling,and injection in-network with an annual value of 15,757 kWh.Additionally,compared to the literature,the heating needs ratio is 6.38(kWh/m^(2).an)and the cooling needs ratio is 49(kWh/m^(2).an),both of which are good values.According to international norms,the inside temperature doesn’t go above 26℃,and the humidity level is within a comfortable range.
文摘Multicriteria Decision Analysis(MCDA)has been integrated with GIS modelling by many studies to aid the decision-making process.This integration enhances modelling by incorporating spatial relationships and using advanced techniques,including the combination of Frequency Ratio(FR)and Analytical Hierarchical Process(AHP),also known as FR-AHP.Although methods like Two-Steps Floating Catchment Area(2SFCA),AHP,and FR are widely applied in measuring accessibility,they have limitations in terms of threshold sensitivity and subjectivity.Hence,this study used FR-AHP,which combines the data-driven strength of FR and the structured decision-making technique of AHP to provide a more reliable evaluation of spatial accessibility.This study aims to integrate FR-AHP with GIS to derive campus spatial accessibility in Shah Alam.Campus spatial accessibility can be measured by using location and distance between origin and destination,topological accessibility for nodes and paths,and contiguous accessibility for surfaces.Understanding these concepts is crucial for determining the appropriate technique.This study utilizedMCDA,GIS-basedFR,andAHPmethods tomodel spatial accessibility in activemobility andpublic transport areas,calculating estimation index values and analyzing comparisons between physical factors.A sample survey was conducted among the university’s students to gather information on their origin and destination,as well as the type of transportation used by students.The data were used in calculating the weightage of each physical factor using the FR-AHP method.Then,the Campus Spatial Accessibility Index(CSAI)was determined by using GIS IndexModelling.By using the model,the index was classified into five(5)classes from Very Low to Very High.The results show that Section 2 has the highest accessibility,while the area with the lowest accessibility index is Jalan Zamrud and Jalan Permata,located in Section 7.To analyze the efficiency of FR-AHP,the CSAI was also derived using theweightage derived fromFR only.The comparisons revealed that the results derived using FR-AHP are closer to reality than those derived using FR only,as it incorporates human preferences in accessibility.Hence,the findings suggest that the integration of FR-AHP could provide better CSAI than FR only.
文摘Ground Penetrating Radar(GPR)is a widely used method that is non-destructive for underground or subsurface detection.It is used in various fields and has proved to be reliable and effective.This research focuses on detecting the presence of air cavities using GPR and analyzing the radargram output based on the compactness of soil and different frequencies.The compactness is used to illustrate the presence of cavities underground artificially.The research examines how variations in the compactness of soil affect the radargram response in showing the presence of cavities using different frequencies.Experimental results demonstrate that lower permittivity materials enhance signal penetration but reduce reflection contrast,whereas higher permittivity materials result in stronger reflections,improving cavity detection.The findings highlight the importance of frequency selection and material properties in optimizing GPR surveys for subsurface anomaly detection,and by having artificially created cavities,the results can be studied to see the changes.
基金financed by Universiti Teknologi Malaysia Encouragement Research Grant(Vot Q.J130000.3852.42J12)to provide incentives and financial support for UTM academic staff to lead research projects that contribute to the university’s research Key Performance Indicators(KPIs)and foster the development of high-quality,competitive research proposals.
文摘The integration of Unmanned Aerial Vehicles(UAVs)and Uncrewed Surface Vehicles(USVs)has revolutionized topographic and bathymetricmapping,significantly enhancing the accuracy and efficiency of geospatial data acquisition processes.This innovative approach synergistically combines terrestrial data collected by UAVs with underwater data obtained through USVs,culminating in the creation of unified high-resolution Digital Elevation Models(DEMs)of the river basin region represents a vital step toward understanding the dynamic interactions between land and water bodies.Hence,the seamless Topo-Bathymetric Elevation Model offers a detailed perspective of the river system,supporting informed decision-making in addressing sediment transport,erosion,and river morphology.This manuscript provides a comprehensive review examines the advanced methodologies for creating seamlessmultisource Topo-Bathymetry ElevationModels(TBEMs)in river basin contexts,emphasising critical factors such as cost-effectiveness,operational efficiency,and data precision.In particular,UAVs deliver high-resolution(1-3 cm)topographic mapping with 5-10 km operational ranges,while USVs provide complementary bathymetric data(1 m resolution)across 3-5 km.This synergy enables seamless land-water surveys,achieving superior precision(±8 cmterrestrial,±3 cmunderwater)and efficiency over traditional methods.By analysing the benefits and limitations inherent in these technologies,this review elucidates the potential of UAV-USV synergy to improve the accuracy and reliability of geospatial data,thereby supporting well-versed decision-making processes in environmental management and conservation efforts.Furthermore,the findings underscore the broader implications of this integrated approach for riverine and coastal studies,advocating for its wider adoption in various applications,including habitat monitoring,flood risk assessment,and sustainable resource management.The synthesis of terrestrial and aquatic data through UAV-USV collaboration not only advances the field of geospatial science but also fosters a deeper understanding of the interdependencies between land and water systems,ultimately contributing to more effective environmental stewardship.
基金supported by the Nexus Young Researcher(NYR)grant,awarded by Universiti Teknologi Malaysia(UTM)for the period of 2024-2026.The grant was provided under Vote Number Q.J130000.3852.42J12.Additional funding was provided through the grant SWK 10.1:The Establishment of a Seamless Vertical Datum for Marine Geospatial Data Reference,under Vote Number R.J130000.7309.1R059.
文摘Single-beam echo sounders remain popular for seabed mapping because they possess an affordable cost and user-friendly design,delivering essential services for marine navigation,coastal management and resource conservation.High-amplitude echoes known as sea-spikes can severely harm depth measurement precision by disrupting readings,thus lowering the overall data accuracy.The manual processing method for outliers produces subjective results and demands excessive labor,which makes it difficult to accomplish trustworthy data processing.The study presents the Sea-Spike Filtering System(SSFS)as a semi-automatic system that utilizes mean absolute deviation(MAD)together with median filter(MF)techniques to efficiently find and eliminate false data in sea observations.The SSFS system showed reliable noise reduction abilities when tested with actual bathymetric data from Bintulu,Sarawak,thus delivering data quality upgrades that fulfilled 59.39%of International Hydrographic Organization(IHO)Order 2 Total Vertical Uncertainty(TVU)guidelines.The Mean Absolute Deviation value decreased substantially from 1.0618 to 0.4314,which enhanced noise reduction without influencing the Residual Mean Square Error or Mean Absolute Error statistics of 1.4188 and 0.9663m,respectively.Thesuccessful elimination of sea-spike outliers through the systemleads to general-purpose survey accuracy,yet more system improvements are required to meet the demanding safety standards in shallow water applications.
基金funded by the Ministry of Higher Education Malaysia(MOHE)through the Fundamental Research Grant Scheme(FRGS/1/2021/WAB07/UiTM/02/1).
文摘Digital ElevationModel(DEM)refers to a digital map of the surface of the Earth that only shows the bare ground,without any buildings,plants,or other characteristics.However,obtaining unlimited access to DEM data at high and medium resolutions is very hard.Consequently,users often question the accuracy of freely available DEMs and their suitability for various applications.By comparing them to Global Positioning System(GPS)elevation data,this study aimed to identify themost reliable and widely available DEM for various terrains.The objectives of this study were to generate DEMs fromdifferent open sources and validate the accuracy of these DEMs using GPS elevation data.Various DEM types including Sentinel-1,ALOS PALSAR,SRTM,AW3D30,and ASTER were compared.Root Mean Square Error(RMSE)andMean Error(ME)were used to measure the difference between the DEM-derived elevations and the GPS-measured elevations.The results showed that even though Sentinel-1 has higher resolutions,the accuracy of the DEM from Sentinel-1 depends on issues including coherence and interferometry,surface features,and temporal stability.On the other hand,ALOS PALSAR could accurately represent surfaces in some situations.Additionally,DEMs with lower resolutions,such as SRTM and AW3D30,demonstrated greater consistency across various types of terrain.In contrast,the ASTER DEM showed more variability in complex terrains.While freely available DEMs are easy to use and accessible,their accuracy varies depending on the source and terrain features.Future improvements could include adding more ground control points and using advanced filtering methods to enhance precision.
基金Funded by University of Malaya (No.GPF015A-2018)。
文摘Cement-based materials (CBMs),such as paste,mortar and concrete,are highly alkaline with an initial high pH of approximately 12.0 to 13.8.CBMs have a high pH due to the existing oxide mineral portlandite and alkali metal contents in Portland cement.The high pH of concrete provides excellent protection and reinforces the steel bars against corrosion.The pH of concrete does not remain constant due to ageing and other defect-causing factors,such as chloride ingress,alkali leaching,carbonation,corrosion,acid attack,moisture and biodegradation process.Reducing the concrete pH has negative impact on the strength,durability and service life of concrete buildings.However,the high pH of concrete may also cause concrete structure deterioration,such as alkali silica reaction,porosity and moisture related damages in concrete structures.The pH of CBMs can be influenced by high temperatures.For instance,the extremely high volume (85%-100%) of slag-blended cement pastes shows considerable pH reduction from 12.80 to 11.34 at 800 ℃.As many concrete structure deterioration are related to concrete pH,using an accurate and reliable method to measure pH and analyse the durability of reinforced concrete structure based on pH values is extremely important.This study is a comprehensive review of the pH of CBM in terms of measurement,limitations and varying values for different CBM types.
基金Project(2015M580491)supported by the China Postdoctoral Science FoundationProject(51404262)supported by the National Natural Science Foundation of China+1 种基金Project(2014XT01)supported by the Research Funds for the Central Universities,ChinaProject supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘The purpose of this work was to explore the influence law of vibration load on rock mass structure and slope stability.Based on the type and transmission way of vibration stress wave,the main stress in the horizontal and vertical directions was analyzed and the superposition effect of the stress wave was revealed.After the mechanical analysis of the sliding mass,the calculation formulas of the anti-sliding force and the sliding force were derived and the damage mechanism of blasting vibration to the structural plane was defined.In addition,according to the structure and lithologic parameter of the slope as well as the vibration monitoring data,the west slope stability of Xiaolongtan open pit mine was analyzed.The results show that the time-dependent stability factor is proportional to the vibration speed and the peak values appear at the same time.Vibration load promotes the breakage of the structural plane leading to the drop of the west slope stability factor by 0.23%.Under the multipoint simultaneous blasting,the fluctuating laws of the stability factors are consistent.The more the start-up points are,the higher the weakening degree to the slope stability is.Under the multipoint allochronic blasting,the stability factor depends on the synthetic waveform structure of all vibration waves.The greater the blasting time difference is,the lower the weakening degree to the slope stability is.Selecting the reasonable quantity of start-up points and time difference could fully reduce the adverse influence of vibration load to slope stability.
文摘A quantitative pH measuring method has been used to measure the pH of pure and blended cement mortars.The blended cement mortars incorporating supplementary cementitious materials(SCMs)such as fly ash(FA),ground granulated ballast furnace slag(GGBFS)and palm oil fuel ash(POFA)were used.Moreover,different variables affecting the pH values of CBMs such as temperature of sample solution,quantity of sample powder,dilution ratio and temporary storage of sample during pH measuring process have been studied for all cement mortars.
基金the National Natural Science Foundation of China(No.10672027)the National Basic Research Program of China(No.2006CB601205)the National Science Fund for Distin-guished Young Scholars of China(No.50625414)
文摘This paper studies the dynamic stress intensity factor （DSIF） at the interface in an adhesive joint under shear loading. Material damage is considered. By introducing the dislocation density function and using the integral transform, the problem is reduced to algebraic equations and can be solved with the collocation dots method in the Laplace domain. Time response of DSIF is calculated with the inverse Laplace integral transform. The results show that the mode Ⅱ DSIF increases with the shear relaxation parameter, shear module and Poisson ratio, while decreases with the swell relaxation parameter. Damage shielding only occurs at the initial stage of crack propagation. The singular index of crack tip is -0.5 and independent on the material parameters, damage conditions of materials, and time. The oscillatory index is controlled by viscoelastic material parameters.
文摘This paper will discuss the computerised developm en t control and approval system being developed for the Planning and Development C ontrol Department, City Hall of Kuala Lumpur, with stress on the GIS architectur e developed within the system. The prospects and challenges towards implementati on of the system are also discussed.
文摘Different modification methods and software programs were developed to obtain accurate local geoid models in the past two decades.The quantitative effect of the main factors on the accuracy of local geoid modeling is still ambiguous and has not been clearly diagnosed yet.This study presents efforts to find the most influential factors on the accuracy of the local geoid model,as well as the amount of each factor’s effect quantitatively.The methodology covers extracting the quantitative characteristics of 16 articles regarding local geoid models of different countries.The Statistical Package of Social Sciences(SPSS)software formulated a strong multiple regression model of correlation coefficient r = 0.999 with a high significance coefficient of determination R^2 = 0.997 and adjusted R^2 = 0,98 for the required effective factors.Then,factor analysis is utilized to extract the dominant factors which include:accuracy of gravity data(40%),the density of gravity data(25%)(total gravity factors is 65%),the Digital Elevation Model(DEM)resolution(16%),the accuracy of GPS/leveling points(10%)and the area of the terrain of the country/state under the study(9%).These results of this study will assist in developing more accurate local geoid models.
文摘The purpose and context for the study relates to urban growth. Australian cities are experiencing particularly rapid urbanization, taking the form of land clearing to accommodate outward expansion as well as developing to higher densities in existing urban areas. Both forms of development degrade native biodiversity, resulting in loss of vegetation with the possibility that the remnant indigenous plants will become locally extinct. One endangered ecological community in Sydney, the Eastern Suburbs Banksia Scrub (ESBS), still survives along some sections of Sydney’s heavily urbanized coastline. At the time of European settlement, the ESBS covered approximately 5300 ha, but it is now a highly fragmented 146 ha across 24 sites with some sites under imminent threat of development. Conservation legislation enacted by the state of New South Wales (NSW), Australia has declared the ESBS as critically endangered. Despite recovery plans, in 2016 the NSW Threatened Species Scientific Committee indicated that the community faces an extremely high risk of extinction in Australia in the immediate future. A practical option in the face of declining open space in our cities is to examine the potential of urban rooftops for conserving and propagating threatened or endangered flora. While there is a limited amount of international research on using green roofs for endangered plant protection, there is no information from Australia about how green roofs perform in this geographic region. The approach taken in this research has been firstly, to review the current academic and “grey” literature from a global perspective to identify options for conserving endangered flora on green roofs. We derive an evidence-based research protocol to be used to test the green roof environment in Sydney for propagating the endangered ESBS. We establish the general applicability of green roofs for protecting vanishing flora through the literature review and conclude that our research design will be a suitable framework for the task for monitoring growth and germination performance over the ESBS community’s development cycle, with the longer-term objective of establishing a viable rooftop seed orchard.
文摘This study investigates the influence of using ground palm oil fuel ash(G-POFA) from 10%-30% as cement replacement(by weight) on the cement mortar's pH under various curing conditions. These findings were supplemented by thermal gravimetric analysis(TGA). Moreover, the resistance of G-POFA blended cement mortars to water absorption and sorptivity was determined. Further, the k-value test was carried out to explain the pozzolanic and filler behavior of G-POFA and to support the results obtained from TGA. It was found that there was no significant impact of several curing conditions on the pH of mortars. The mortar with 10% G-POFA in replacement of cement(G-POFA-10) exhibited the best resistance against water absorption and sorptivity.
文摘The purpose of this paper is to implement and validate a decision making framework for building maintenance projects. The growing importance of maintenance sector not only in Malaysia but al- so increasingly globalized, the difficulty in selecting an appropriate procurement method and lack of research in this area provide an impetus for this research. There were 19 procurement selection criteria identified. In addition, there were 4 types of procurements methods which include outsourcing by specialist term contract, outsourcing by tendered schedule term contract, out- sourcing by repair and maintenance contract and outsourcing by measured term contract identified to be the most popular procurement methods adapted by public universities currently and at the same time were considered most important. The decision making framework was developed based on AHP technique and principles. Expert Choice Software was employed as development tool where the criteria and alternatives were integrated into the framework. Finally, structured interview was conducted to validate the framework developed. The validation process was carried out through structured interview with selected public university.
文摘Optimizing the combined horizontal and vertical accuracy of the well-known Global Digital Elevation Models(GDEMs) of various resolutions for each country and region especially in Iraq’s mountainous areas is still questionable. All the three GDEMs, approximately, have the same vertical accuracy with the Root Mean Square(RMSE) of ±7.3 m, ±7.6 m and ±6.5 m via 12 fixed Ground Control Points(GCPs) for the Advanced Land Observation Satellite Phased Array L-band Synthetic Aperture Radar(ALOS PALSAR 12.5 m), the Shuttle Radar Topographic Mission(SRTM 30 m) and the TerraSAR-X(the name of twin satellites) add-on for Digital Elevation Measurement(TanDEM-X 90 m) GDEMs respectively. Moreover, the percentage of outliers that are greater or smaller than ±10 m detection of the height extraction from both the ALOS PALSAR and SRTM Digital Elevation Models(DEMs) contains 16.7% and for TanDEM-X was 25%. In this paper,the special DEM is derived using 2123 handheld GPS points for Sulaymaniyah Governorate, Kurdistan region, Iraq. The height extraction by discarding the outliers of 58% gives the RMSE of ±8.0 m in the case of adding geoid heights(N) to the ellipsoidal heights(h) via the Earth Gravitational Model 2008(EGM2008)and ±5.6 m without adding N. It is expected that the derived DEMs will give more accurate results both horizontally and vertically in the mountainous areas when GPS observations are intensified. The horizontal accuracy is validated through extracting hierarchy stream types of the watershed map from the DEMs for higher than 100 pixels length. The ALOS PALSAR DEM extracted more numbers of stream orders than others.Finally, based on the criteria of RMSE, outlier detection, and the number of extracted stream orders, the ALOS PALSER DEM is regarded as the optimal GDEM in comparison with the close accuracy of both the TanDEM-X and SRTM DEM.
文摘Lack of preventive measure is currently the problem that implicates poor building maintenance performance and issue on sustainability of buildings in Malaysia. Whereby, preventive maintenance is an effective approach to enhance the reliability and quality of a system and its components. This study seeks to investigate the characteristics of preventive maintenance towards the overall performance in building maintenance. Case study approach is adopted to identify the maintenance characteristics and aspects that lead to good performance. The research findings demonstrate that the most significant maintenance characteristics towards overall performance are skill and knowledge of maintenance labour, quality of spare parts and materials, length of predetermined maintenance interval, skill and knowledge of maintenance manager, capability to adopt maintenance equipment and technique, budget allocation for acquisition of maintenance data, reliability of maintenance data, as well as frequency of monitoring and inspection. As a conclusion, the significant maintenance characteristics must be taken into consideration to achieve optimal maintenance performance. In order to improve the effectiveness of maintenance strategy and the maintenance performance, the study recommends practice and provision of communication platform such as meeting and customer satisfaction survey that involves all the key participants from clients to customers.
文摘The increasing of development failure on highland urges the professionals to develop solution on mitigating the problems. This paper discusses on land development process and legislation on highland development in Malaysia and Hong Kong. This study is focus on land use planning, laws and regulations pertaining to land development process. Hence, this research is to review the current development process including mechanism and legislation pertaining land development on highland in Malaysia and Hong Kong. Hong Kong is chosen as an example based on the fact that for its successfulness in managing highland developments. The main aim of this research is to evaluate the effectiveness of land development legislations and development approaches for highland development. This research reveals the effects and consequences of implementation regulations and development process on highland that have been used at Malaysia and Hong Kong. In Malaysia, land development process on highland is still in questionable;why present property laws and regulations are fail to achieve highland development standards as compared to Hong Kong. There are weaknesses that need to be overcome such as on the implementation and the intensity of the provision in property laws and regulation that can ensure the achievement of required land development process.
