Pusat Pengajian Kejuruteraan Awam - Tesis

Browse

Now showing 1 - 20 of 142

3D rock slope stability assessment using anisotropic materials model
(2020-10-01)
Nagendran, Sharan Kumar
Rock anisotropy is a well-known phenomenon relating to the heterogeneity of rock mass. Nevertheless, its influence in geotechnical design, especially in rock engineering, is often ignored. Slope with certain modes of failure can be evaluated conventionally as well as numerically. For this study, the rock slope assessment was conducted numerically using 2D and 3D Limit Equilibrium Method (LEM) utilizing the Slide program by Rocscience. The fundamental roles of the discontinuities present in the study area were evaluated to study their influence on slope stability. Anisotropic material model was incorporated in the LEM analysis to investigate the presence of discontinuities. The measurement of discontinuity orientation in the rock slope by traditional scanline survey is time-consuming and challenging due to accessibility issues. Structure from motion (SfM) photogrammetry using Unmanned Aerial Vehicle (UAV) allows a quick and cost-effective way to do survey mapping for geotechnical assessment on rock slope compared to terrestrial laser scanner (TLS). Dense point cloud is exported to the CloudCompare tool for geological plane extraction. The stability of the rock slope was evaluated using the deterministic 3D and 2D Limit Equilibrium Method (LEM) using the geometry of the 3D rock slope system. In this study, the anisotropic material model was utilized to examine the Factor of Safety (FoS) results. Generalized anisotropic material model was used for incorporating the Generalized Hoek Brown criterion (rock mass), Mohr Coulomb (weak joint) and Barton Bandis criterion (weak joint). The rock mass and shear strength parameter for numerical analysis were determined via destructive and non-destructive tests such as Uniaxial Compressive Strength (UCS), Schmidt Hardness and JRC estimation using Barton comb. The discontinuities extracted are reliable and accurate as they are within 10° of the data measured manually. By using discontinuity data, the kinematic analysis shows that the rock slope has 12.80% of risk in planar sliding, 6.67% in wedge sliding and 1.93% in flexural toppling. Mean dip / dip direction obtained was used as an input for the value of the anisotropic plane where it causes a weakness in the strength of the rock slope. The results of FoS shows that rock slope without anisotropy model is stable and analysis using anisotropic material model predicts that the slope may fail. 3D slope stability analysis was able to identify the weakest spot easily rather than to assume based on the results of 2D slope stability assessment which might represent the whole rock slope. 3D rock slope stability assessment proves to be very cost-effective method for remedial work whereas in 2D stability assessment, wrong cut-sections may provide inaccurate FoS. This study presents the approach of using anisotropic material model utilizing basic rock testing and field observation data to analyse the rock slope stability.
A novel cu-sio2 nano-catalyst electrode for the treatment of chloride ion from Eshidiya mine wastewater, Jordan
(2023-12-01)
Mohammad Salem Abdullah Alhwaiti
This study aims to develop new technology concepts using Cu-SiO2 nanocatalyst electrodes for treating industrial mine wastewater by reducing chlorine ions present in the wastewater discharged from the Eshidiya mine in South Jordan. A developed Cu-SiO2 nano-catalysts were developed to reduce the Cl– concentration in Eshidiya mine wastewater. Copper sulfate and Tetraethoxysilicate (TEOS) form a sol-gel, dried, and calcined to form Cu-SiO2; subsequently, a blend of copper-silica and dry graphite powders was coated onto a Cu wire, creating a Cu-SiO2 nano-catalyst electrode. Electrochemical mechanisms, reaction kinetics, electrode regeneration, and efficiency of the electrode were evaluated. The optimal condition for Cu-SiO2 nano-catalyst electrodes entailed examining their impact on chloride removal efficiency through the investigation of variable scan rates, initial chloride concentrations, pH concentrations, current density, and electrode sensitivity. The Brunauer-Emmet-Teller (BET) results revealed that the surface area and pore volume of the Cu-SiO2 were 470.7309 cm2/g and 0.296093 cm3/g, respectively. The Cyclic Voltammetry (CV) results indicated that the chloride ion at a scan rate of 5.0 V/s reduced the anodic peak potential by 0.11 V and decreased the current density to 5.8 mA/cm². The Tafel Plot shows three significant peak potentials at -0.005, 0.052, and 0.104 V. The i-t curve showed that the electrode reached an equilibrium activity that required regeneration to be activated by reversing the voltage from 0.71 volts to 0.71 volts.
Adsorption efficiency of tetracycline in aqueous solution using cellulose nanocrystal – layered double hydroxide
(2024-10-01)
Mohammad Saood, Manzar
Tetracycline antibiotics (TC) are known to be toxic to microbial communities and can accumulate as it rises up the food chain, which enhances the growth and spread of antibiotic resistance. Adsorption technology is one of its treatment options, but commercial adsorbents such as activated carbon, silica gel etc. have poor reusability and adsorption capacity. Cellulose is a bio based material that is known to reinforce parent material with fillers like layer double hydroxide (LDH) in order to produce environmental friendly and sustainable nanomaterial products that have accessibility in landscaping, good biodegradability and is non toxic. A unique, sustainable CNC layered double hydroxide biocomposite was developed in this study for the efficient sorption of TC from the aqueous phase. SEM, XRD, FTIR and BET surface area analysis were conducted to characterize the adsorbent produced. The adhesion of cellulose nanocrystals (CNCs) to the surface of MgAl-LDH and MgFe-LDH was validated by SEM images and XRD patterns. High specific surface areas of 101.927 and m2 g-1, respectively, were displayed by CNC-LDH and CNC-MgFe-LDH composites. The adsorption mechanism and environmental valuation were explored by means of dissimilar adsorption models. Pseudo-second-order kinetic models and data on adsorption kinetics are closely related as it has high fitting quality. Tetracycline was found to be less rapidly eliminated in the occurrence of electrolytes in the solution. Adsorption rapidly reaches its maximum adsorption capability after 180 minutes of material contact. The Langmuir isotherm model provided a more accurate fit to the equilibrium data for two adsorbents (CNC-MgAl and CNC-MgFe LDHs), with a maximum adsorption capacity of 165.49 and 153.3 mg g-1, respectively. Spontaneous endothermic adsorption was predicted by thermodynamics. The tetracycline removal efficiency of the adsorbents was close to 40 mg g-1 for both CNC-LDHs even after five regeneration rounds. In conclusion, the composite shows great prospective in cleansing the tetracycline contaminated water.
Adsorption studies of heavy metals on activated carbon prepared from agricultural waste
(2018-03)
Muhamad Faizal bin Pakir Mohamed Latiff
Commercially available activated carbon (AC) is still considered expensive due to the use of non-renewable and relatively expensive starting material such as bituminous coal. Therefore, this study investigates the potential use of agricultural waste such as rubber seed coat (RSC) and corncob (CC) that available in Malaysia, as the precursor for the preparation of AC which can be applied for the removal of two types of heavy metal, which are Cu (II) and Zn (II) from aqueous solution. Physiochemical activation consisting of potassium hydroxide (KOH) impregnation plus carbon dioxide (CO2) gasification was used to prepare the ACs. The optimum preparation conditions of RSCAC-CU were found at activation temperature of 793 °C, activation time of 1h and KOH impregnation ratio (IR) of 2.46. As for RSCAC-ZN, the optimum preparation conditions were at activation temperature of 797 °C, activation time of 1h and IR of 2.61. Meanwhile, the optimum preparation conditions of CCAC-CU were found at activation temperature of 762 °C, activation time of 2.7h and IR of 3.25. For CCAC-ZN, the optimum reparation conditions were at activation temperature of 768 °C, activation time of 3h and IR of 3.5. All the activated carbons prepared were high BET surface area (>500 m2/g) and pore volume (>0.41 m3/g). RSCAC and CCAC demonstrated homogeneous and heterogeneous type pore structures, respectively. The effects of adsorbate initial concentration (10-100 mg/L), contact time, solution temperature (30-60 °C), solution pH (2-6), isotherms and kinetics of the adsorption systems were evaluated through batch adsorption test. The Cu (II) and Zn (II) adsorption uptakes increased with increasing initial concentration and optimum contact time. Adsorptions of Cu (II) and Zn (II) on all ACs were best fitted by the Freundlich isotherm model. Adsorption kinetics of Cu (II) and Zn (II) followed pseudo-second-order on all the ACs. Fixed bed study showed that the exhaustion period for Zn (II) was greater than Cu (II) and the increase in bed heights resulted in higher exhaustion period.
An integrated procurement process framework for public sector projects in iraq
(2024-04-01)
Alsamarraie Mundher, Mohammed Saeed
Public procurement is a robust activity encountering enormous challenges that impede efficient functioning. The procurement process suffered from corruption, project team disintegration, poor performance, and high-risk issues due to several obstacles at various stages. This study aimed to uncover the weaknesses in the procurement process and investigate the barriers to integrating the contracting practice with the public procurement system. The scope of the study covered the implementation of the projects in the public sector of Iraq, and the respondents for this study were the funding bodies, authorities, consultants, contractors, and engineers. The limitation of the study was in the small number of public sector organizations and its key projects. Moreover, the study proposed a conceptual model and developed a detailed framework to lead the integrity of the process and ensure organizational consistency. The researcher used mixed methods to cover the research objectives and test hypotheses. From the qualitative analysis, the systematic literature review (SLR) determined the procurement system's related issues and evaluated organizational public procurement performance for construction projects. Furthermore, the researcher conducted a Delphi study by interviewing experts in the field regarding the conceptual model. The Delphi study continued to identify the advantages and barriers towards adopting the framework. On the other hand, the quantitative method used a questionnaire survey to identify the obstacles to integrating the procurement process and to test the model fit. The data was collected and analyzed using QDA miner, IBM SPSS, and Amos software. Eventually, the proposed model and the detailed framework witnessed wide acceptance among experts due to the accessibility and simplicity of developing such a framework in the procurement system in Iraq. This framework assisted in transitioning from a procedure-based to a knowledge-based organization. The findings addressed numerous indicators, and the researcher categorized them into thematic classifications according to their impact on socio-economic, organization planning, project-related, and operational indicators. In addition, the study demonstrated the significant effects of Team Collaboration (TC), Process Disintegration (PD), Corruption Activities (CA), Transparency Issues (TI), Weak Procurement Performance (WP), Claims and Project Performance (CP), and Risk Issues (RI) in the procurement system and contracting process. The framework contributed to reconstructing and developing the procurement process to increase central decisions and create a healthy environment to introduce more integrated frameworks. It improved procurement and project performance and supported open discussion of a project team, effective communication, information exchange, honest attitudes, and trustful relationships. Moreover, it recommended partial employment of e-procurement in pre-contracting activities for project effectiveness.
Analysis of biochemical and morphological properties of fine particles (pm2.5) from high particulate event (hpe)
(2023-02-01)
Nur Amanina Binti Ramli
The current investigation focuses on the health and environmental impacts of elevated levels of fine particulate matter (PM2.5) in the air. Past research in Malaysia have only collected data on concentration and elemental composition and have not examined the morphological properties or biological components of PM2.5. Middle-aged and elderly people, particularly farmers, are most negatively impacted by straw burning on their health, so those who are more susceptible and are exposed to the smoke from straw burning on a more frequent basis are more likely to experience a decline in their health as a result of high particulate event from straw burning. Therefore, this study focuses on determining the compositions of trace elements and the morphological and biological properties of fine particles which the species of bacteria found in bioaerosol from high particulate event were discovered in this study. For morphological observation of fine particles, FESEM was used in this study. Two main categories of particles were found, which were natural particles and anthropogenic particles. The zinc element was found during the morphological observation and was assumed to come from the fertilizer used by the farmers. ICP-OES identifies the concentration of trace elements in the fine particle samples. A cultured method was used in this study by using nutrient agar. From this study, several bacteria were identified: Exiguobavterium indicum, Bacillus amyloliquefaciens, Desulfonema limicola str. Jadabusan, Exiguobacterium acetylicum, Lysinibacillus macrolides, and Bacillus proteolyticus. This study is important, especially for human health and further research on the biological composition of aerosols should be conducted to understand the effect of microorganisms on human health. Finally, PCA-MLR analysis revealed a road dust contributed up to 56%, biomass burning contributed 30%, minerals contributed 9%, and vehicle emissions contributed 5%. at S4 and S5 during high particulate occurrences. In comparison to non-high particulate occurrences, 50% contribution from mineral, a 26% contribution from vehicle emissions, a 17% contribution from road dust, and a 7% contribution from biomass burning. Hence from this study, local authorities will be able to monitor and predict high PM2.5 concentrations in high particulate event areas as well as local biomass burning regions, as well as provide consultation and raise PM2.5 awareness among local farmers.
Analysis on self-reported risky riding behaviour of motorcyclist using partial least square structural equation modelling
(2021-10-01)
Goh, Wins Cott
This study was conducted among Malaysian motorcyclists to address the high fatality rate of motorcycle traffic accidents. Research has shown that age, gender, likeness towards a risky riding behaviour (positive affect), and perception of risky riding behaviour significantly impact a rider’s judgement on the road. Thus, this study is initiated to better comprehend the behaviour of Malaysian motorcyclists. A study was conducted to obtain demographic information, risky behaviour engagement, positive affect, and risk perception among Malaysian motorcycle riders. The survey results were then analysed using the Structural Equation Modelling – Partial Least Squares approach to assess the survey's reliability and validity. Consequently, a statistical model was created based on the hypothesis model, where the relationship among each latent construct is evaluated. The statistical model in this study included age, gender, riding experience, trip distance, motorcycle type as the construct of personal characteristic. A total of four hypotheses are accepted from the initial six hypotheses. Crucial evaluation from the model reveals that the positive affect construct has the strongest positive relationship with the construct of risky behaviour (t-value = 15.517). Findings in the model also show that the personal characteristics of rider has a direct effect on risky behaviour (t-value = 2.175). In addition to these findings, the model has also revealed an indirect effect from personal characteristics towards risky behaviour through positive affect was also significant (t-value = 3.885). These results concur with most studies conducted on motorist driving behaviour. Thus, with these findings, it can be concluded that risky behaviour engagement of Malaysian motorcyclist reduction should be approached from the perspective of encouragement and empowerment instead of enforcement and deterrence.
Anti-vortex device efficiency for pump sump using hydraulic physical model
(2024-07-01)
Wahidah, Nur Rizzuan
Pump sump design is very crucial in order to optimize pump inflow and pump efficiency. The pump may become damaged as a result of the vortex that forms around the pump sump suction area. The vortex may change particle velocity and increase impeller erosion. A vortex is a special form of fluid motion, with unstable and nonlinear characteristics. There are two types of vortices that occur at a pump station inlet: a submerged vortex and a free surface vortex. The free surface vortex has a great impact on the project, which will reduce the effective water flow section at the inlet of the pump station and reduce the flow capacity. To increase pump efficiency, a phenomenon called vortex generation near the pump entrance in the sump during intake needs to be managed. In this study, a pump sump model is equipped with five variations of an anti-vortex device (AVD) types at five different water level in order to assess how the anti-vortex device design affects the efficiency of vortex management in the intake flow. According to the ANSI/HI standard, the sump that produced vortex must be eliminated and the swirl angle in the flow must not be greater than 5°. All AVD variations used in this study were successful in removing the free surface vortices (FSV) at high water level (853.5 mm, 638.5 mm and 463.5 mm) but the majority of them occurred at low water level (400 mm and 370 mm). This can be avoided by placing modification of an anti-vortex device (AVD) which are back wall fillet and Floating-Anti Vortex Device (F-AVD) near the intake pipe in the pump sump. The function of Floating Anti-Vortex Device (F-AVD) is to prevent and eliminate the formation of vortices and swirl in the water flow during low water level. Proved that after placing the back wall splitter and F-AVD, the swirl angle is reaching less than 5° which achieve the lowest swirl angle reading (2.3°). As opposed to a case where there is no AVD, the application of back wall splitter and F-AVD greatly improves performance in swirl angle reduction and vortex suppression.
Application of machine learning technique to estimate modal choicefor kuantan city
(2023-02-01)
Nur Fahriza Binti Mohd Ali
The machine learning technique has been rapidly adopted due to its effectiveness in modelling travel mode choice when compared to the conventional technique of Discrete Choice Modelling by means of Logistic Regression. The general aim of the work reported in this thesis is to identify a promising alternative approach for modelling travel mode choice effectively for solving the current transport problems in Kuantan. To achieve those aims, the research must satisfy its three main objectives; to identify the parameters contributing to users’ daily travel mode choice; to develop machine learning models that can classify users’ daily travel mode choice; and to analyse the implications of the machine learning technique for modelling future travel mode choice. The Revealed/Stated Preference (RP/SP) survey method was used involving 386 respondents in Kuantan City, Pahang, Malaysia. The travel mode choice modelling for door-to-door journeys which includes walking distance from home to the nearest stop (WD1), waiting time (WT), in-vehicle time (IVT), and walking distance from the last stop to destination (WD2). The implementation of feature importance by means of feature selection technique depicted that WT, total Travel Time (TT), Region, WD1, Ticket, IVT, Reason of that journey, WD2, Employment Status, and age of respondents are significant compared to the remaining variables. Some notable machine learning models were developed and compared to depict the most effective model for travel mode choice. They were Neural Network (NN), Random Forest (RF), Logistic Regression (LR), Naïve Bayes (NB), k-Nearest Neighbour (kNN), Decision Tree (DT), and Support Vector Machine (SVM). Among them, Neural Network (NN) was the most effective in modelling travel mode choice with the Classification Accuracy (CA) of training and testing of about 0.727 and 0.721 respectively, followed by LR (training: 0.714, testing: 0.714), RF (training: 0.713, testing: 0.685), NB (training: 0.697, testing: 0.675), DT (training: 0.661, testing: 0.660), kNN (training: 0.667, testing: 0.673), and SVM (training: 0.555, testing: 0.558). Additionally, via the data augmentation technique, prediction by means of NN model delivered an optimum achievement in term of users’ interest to choose public transport when the total travel time (TT) was improved by 30%, from an initial 1165 private vehicles (N) users being reduced to 561 users whilst 791 public transport (P) users had increased to 1395 users. On average, users were triggered to switch mode from private vehicles to public transport if the provided travel time follows accordingly to their need or expectation, which were WD1 (4.49 minutes), WT (9.55 minutes), IVT (24.89 minutes), WD2 (4.97 minutes), and TT (43.90 minutes) with fares RM 2.93 for a journey of about 40 kilometres from Kuantan City. It can be concluded that the machine learning technique is an effective approach to develop travel mode choice modelling.
Application of tin (IV) tetrachloride and jatropha curcas in coagulation-flocculation process for the treatment of stabilised landfill leachate
(2021-11-01)
Syed Zainal, Sharifah Farah Fariza
Leachate is one of the most common problems faced by landfilling methods that can jeopardize the life and environment due to the excessive concentrations of pollutants. It must be treated first before discharge into the environment. The coagulation-flocculation (C-F) process has been extensively used in landfill leachate treatment. However, leachate needs high strength coagulant to remove higher pollutants. The application of tetravalent metal salts coagulant in combination with a natural coagulant and the effectiveness of tetravalent metal salts in a C–F process is still inclusive. This study was performed to determine the best C-F operational conditions such as pH and coagulant/flocculant dosage, rapid mixing, slow mixing, and settling on the removal of chemical oxygen demand (COD), colour, and suspended solids (SS) in a stabilised leachate from Alor Pongsu landfill site, Kerian, Perak as a case study site. Tin (IV) Chloride (SnCl4) and Jatropha curcas (JC) seed or ‘buah jarak’ was tested as a sole coagulant and later mixed with JC reacted as a flocculant. A series of jar tests were conducted, and the C-F mix was optimised using response surface methodology (RSM) and central composite design (CCD). Floc’s size and sludge properties were also evaluated, followed by an acute toxicity test on the raw and treated effluent. Excellent removals of 99.5 %, 98.4 %, and 71.5 % for SS, colour, and COD, respectively, were obtained by using 11.1 g/L of SnCl4 as coagulant alone at pH 8. JC seed was poor as a sole coagulant with only 33.9 % and 23 % reductions in colour and COD, respectively, with no removal in SS. However, with the combination of SnCl4 as a coagulant and 0.9 g/L of JC seed as a flocculant, the SnCl4 dose was reduced to xxiv 8.5 g/L with 99.8 %, 98.5 %, and 74.3 % reductions in SS, colour, and COD, respectively. The sludge and floc characteristics tested showed that JC helped in producing larger flocs, increasing the sludge velocity, and having a higher flocculation index. The treated sample with SnCl4 as coagulant and JC as a flocculant could reduce the toxicity effects to tested Tilapia fish and is safe to be discharged at appropriate dilution concentrations. It can be concluded that JC seeds have the potential to be applied as a natural flocculant with SnCl4 as the main coagulant in the treatment of leachate. This could reduce the dose of the inorganic commercial coagulants currently in use with better sludge properties.
Assessment of non-seismically designed timber-concrete hybrid building under earthquake scenario in Malaysia using shake table test
(2022-08-01)
Richard Ng, Eng Yao
Most of the buildings in Malaysia have not considered lateral loads in the design, especially traditional houses. Therefore, they may be susceptible to damage caused by earthquake as demonstrated in the past earthquakes. In addition, no shake table test has been performed on traditional houses in Malaysia. Previous studies show that irregular buildings perform poorly when earthquake strikes. Thus, this research aims to study the seismic performance and develop the correlation of response for L-shape in plan buildings with various frequencies under different peak ground accelerations (PGAs). In this study, the model was down-scaled into 1:4 and has been built in the hybrid timber-concrete floor system. The model was tested with different types of ground motions, i.e. near field and far field with large displacement and various PGAs, namely, 0.05, 0.08, 0.12 and 0.16 g. The building frequencies within 2.70 Hz to 6.25 Hz were varied by changing the lateral force resisting system. The largest roof acceleration difference for the shorter wing section to the longer wing section of the building was 1.12 times; whereas the largest roof displacement difference for the shorter wing section to the longer wing section of the building is 1.17 times. The experimental result shows torsional effect. Numerical analysis based on interpolation of excitation for a single degree of freedom system was also performed to compare with the experimental results. The maximum roof displacement at shorter and longer wings of the building based on experimental analysis is 1.85 and 1.67 times larger than that predicted by numerical model based on single degree of freedom system, respectively. Prediction equations for the maximum responses (accelerations and displacements) based on building frequencies and PGAs for near field and far field with large xxiii displacement earthquake were proposed at the end of the study. This study helps to understand the response of the L-shape irregular hybrid timber-concrete structure. Moreover, the prediction equations developed were able to help engineers to design new buildings and to strengthen the existing buildings to withstand earthquake excitation.
Assessment of renewable energy potential using hec-ras river flow modelling for basra river bank development
(2024-01-01)
Ali Dhafer, Abed Yaha
Hydroelectric power from hydro turbines is one of the most widely used renewable energy sources because it contributes to the reduction of greenhouse gas emissions and environmental pollution. For a hydro turbine to generate power it needs to convert the kinetic energy of the water into electricity using rotors placed along the free-flowing paths of the river, that is, a continual flow of water or pressure is needed to rotate the turbine, and this pressure can be generated through what is known as blue energy. Therefore, this research focused on predicting the renewable energy produced by the six main rivers branching from the Shatt al-Arab within Basra city. The main problem of these rivers was they turned into stagnant swamps in which the flow and continuous renewal of water do not occur with the tidal phenomenon as a result of the adverse effects of the neighboring land uses. The aim was to simulate the water in this system according to remote sensing data to reveal the flow characteristics and land uses that affect its properties as well as develop planning and design treatments to restore these rivers' flow, treat their pollution, and predict the osmosis and hydro turbine power values. The study reached to derive an equation that calculates the power generated from the turbine based on the osmosis power, which is used after proposing a set of treatments for the river path and its banks and testing it with a simulation model. The study found that the highest and lowest power density per unit membrane area can be generated in November and March in the systems of Saraji-Khora, Ashar-Khandaq, and Rubat-Jubaila, with values that ranged between 38.99-1.68, 30.75-1.99, 30.29-1.31 W/m2 respectively. As for the turbine power that can be generated per unit area at the downstream of the same rivers, depending on the osmosis power, it ranged between its highest and lowest values of 0.21-6.86, 0.2-4.75, 0.14-4.69 W/m2 . The highest turbine power that can be produced along the stations of the three systems, depending on the tidal flow, peaked in March at the downstream of the three systems with 0.403, 0.701, and 0.529 MW, respectively. The lowest power of the tidal turbine was recorded in November at the upstream of the systems with 0.001 MW. The study recommends the necessity of preserving the tidal velocity and discharges that ensure the renewal and continuous flow of unpolluted water inside the rivers. It also recommends installing plants to produce osmosis power using PRO (Pressure Retarded Osmosis) technology at the downstream of the Shatt al-Arab systems, in order to increase the osmotic pressure difference and water flux, which doubles and increases the amount of power that the turbine will produce.
Assessment of the flow characteristics of a dam physical model with anti-vortex structure using computational fluid dynamics
(2023-05-01)
Thiennieesh A/L Manogaran
Dams are structures that are being used to oppose or halt the flow of water in a stream or river. Unfavourable flow characteristics in the dam can cause problems such as fluctuation in pressure, loss in discharge capacity as well as problematic flow conditions in tunnels ad turbines. This research describes the physical modelling performed on the physical model of a dam reservoir with a distorted scale of 1:100. Particle Image Velocimetry (PIV) approach was implemented since it has evolved into one of the most prominent non-intrusive flows measuring techniques and was able to measure flow parameters such as velocity and discharge which had a good data agreement with Nixon Streamflow Velocity Meter. Free-surface vortices (FSV) were also detected through velocity vector instantaneously. CFD modelling enables to analyse flow patterns in the model, such as free-surface vortices. The model of the 1:100 scale dam reservoir was generated, computationally meshed, and modelled in FLUENT under ANSYS 2019 R3 at two different water levels to observe the FSV formations. To mitigate those FSV formations, anti-vortex plates with two distinct plates—square and wedge—were used. From the findings square plates outperform wedge plates because square it lowers the speed of a fast-flowing fluid and reduces it into a laminar flow rather of a turbulent flow, which benefits vortex class deterioration. Data from the simulation and experimental shows a strong agreement in terms of velocity less than 20%. From this study, the modification could be adapted to avoid the FSV formation in the real dam model when designed under suitable guidelines for vortex structures.
Challenges and benefits of sustainable green buildings for the achievement of sustainable development goals (sdgs) in Jordan
(2023-01-01)
Farah Hussain Saaed Ahram
Jordan faces several obstacles that are shared by other Middle Eastern developing countries. Jordan's current difficulties with sustainable development include unsustainable activities in many sectors and poor progress toward the Sustainable Development Goals (SDGs), particularly in its building industry. This study aims to explore the challenges and benefits of Sustainable Green Buildings (SGBs) during the life cycle of green building projects according to the three main pillars of sustainability on SDGs achievement in Jordan. This study used a qualitative approach, with semi-structured interviews serving as the primary data collection method. The data from the semi-structured interviews were analyzed using content analysis by ATLAS.ti software and then discussed and interpreted in order to develop a conceptual framework. The findings of this study show that the challenges and benefits of SGBs in Jordan as a developing country, according to the three main pillars of sustainability influenced the accomplishment of SDGs in the built environment throughout the entire life cycle of green building projects. It is discovered that SDG 11(Sustainable cities and communities) and SDG 13 (Climate action) are the most influenced sustainable development goals that were affected by all challenges faced by SGB at all project stages. It is also discovered that SDG 8 (Decent work and economic growth) is the most affected SDG that was influenced by all benefits achieved from the SGBs at all project stages. The results are expected to enrich the knowledge on the implementation of SGB in developing countries in relation to the attainment of SDGs
Coagulation process of textile wastewater using composite coagulant - zinc oxide, acrylamide and tannin (zopat)
(2021-09-01)
Ishak, Siti Aisyah
Composite coagulant is known as the combination of two or more polymer into one compound either through structurally, chemically or functionally. The addition of chemical charged molecules can destabilize the suspended colloidal particles and settled down the flocs. The primary aim of this research was to synthesis composite coagulant ZOPAT from zinc oxide (ZnO), acrylamide (PAM) and tannin. To achieve this the different ratio was applied during blended technique for 24H. The jar test condition was experimented at various pH, dose, rapid mixing, slow mixing and sedimentation time to get the optimum coagulation process. Then, Response Surface Methodology was applied using Central Composite Design to achieve the optimum pH and ZOPAT dose. In addition, the formation of floc and sludge were studied and compare before the treatment. This research was the first to incorporate zinc oxide (ZnO), acrylamide (PAM) and tannin as ZOPAT using ratio (A) 1:1:1. The optimum condition for pH and ZOPAT dosage analysed throughRSM-CCD resulted in 93% of colour, 80% of COD, 100% of turbidity and suspended solids were obtained at the pH 9.22 and 737 mg/L ZOPAT. The performance of ZOPAT indicate better sludge settleability which resulted in sludge volume index at 74.42 mL/g, and settling velocity at 1.63 cm/min. The present of Zn, N and K contribute to electrostatic attraction with the opposite charge particles. The chemical bond form between dye-particle-dye with amide, hydroxyl, carboxyl groups in ZOPAT can remove the colour, turbidity, COD and SS.
Coagulation-flocculation process by tin tetrachloride (sncl4), rubber seed, polyacrylamide (pam) and sedifloc in landfill leachate treatment
(2023-09-01)
Siti Fatihah Binti Ramli
The goal of this study is to assess the effectiveness of tin tetrachloride (SnCl4), rubber seed (RS), polyacrylamide (PAM), and Sedifloc as coagulants/coagulant aids for the removal of colour, COD, suspended solids (SS), and UV254 from high strength leachate. Divalent and trivalent metal-based coagulants were the primary focus of earlier research on leachate treatment. Tetravalent coagulants have not yet been extensively studied for application in leachate treatment. The same case goes for RS, PAM and Sedifloc. There are no reported studies to date on the use of RS for the treatment of high-strength leachate. The leachate samples in this study were collected from the aged Alor Pongsu landfill site located in Alor Pongsu, Perak, Malaysia and multi-series of coagulation-flocculation experiments were conducted in standard jar test procedures. The results found that, the optimum condition for SnCl4, RS, PAM and Sedifloc when used alone was rapid mixing of 220rpm-4 minutes, 120 rpm-10 minutes, 180 rpm-8 minutes,220 rpm-8 minutes; slow mixing of 60 rpm-30 minutes, 60 rpm-20 minutes, 60 rpm-30 minutes, 60 rpm-20 minutes; settlement time of 40-45 minutes; optimum dosage (10,000 mg/L, 6000 mg/L, 1000 mg/L, 500 mg/L); optimum pH (pH 8, pH 3, pH 2, pH 2), respectively. When SnCl4 was used alone, the removals obtained for colour, SS, COD and UV254 were 98.9%, 100%, 74.5%, and 95.7%, respectively. However, RS, PAM and Sedifloc were found ineffective when used alone. When used as the coagulant aid, the obtained removal percentages were comparable to SnCl4 alone. The dosage of SnCl4 was reduced from 10,000 mg/L to 8,000 mg/L when RS was used as a coagulant aid and to 6000 mg/L with the usage of PAM and Sedifloc. Characteristics of the sludge supported that the main mechanism involved for SnCl4 was charge neutralization and bridging for RS, PAM and Sedifloc. It was also found that the functional groups such as amine, carboxyl and hydroxyl are the active functional groups components that are responsible for the effective coagulation and flocculation activities. It was found from the study that 6000 mg/L SnCl4 in the presence of 100 mg/L Sedifloc is the best option in removing pollutants in leachate and also improves the characteristics of sludge after the treatment. Therefore, SnCl4 use in conjunction with Sedifloc was chosen as the best condition for the treatment of Alor Pongsu and other equivalent leachates.
Community resilience and disaster readiness for sustainable coastal development in malaysia
(2024-01-01)
Amarpreet Kaur, A/P Mahinder Singh
Malaysia is considered as a high-risk country due to the increasing number of natural disasters occurrences in recent years, particularly in its coastal areas. With a growing population and critical infrastructure development along the coast, coping mechanisms include increasing resiliency in coastal communities and cities. Community members should prioritize disaster readiness based on perceptions of risks and establish disaster control committees. Prioritizing human aspects in disaster management is crucial. However, community resilience features have not been clearly established and assessed in Malaysia. This study aims to evaluate community resilience in disaster preparation levels for sustainable coastal development, focusing on critical components to assess disaster preparedness. A quantitative research method was conducted using a close-ended questionnaire survey for data collection on the perspectives of the community resilience on disaster readiness for sustainable coastal development in Malaysia. In this study, community resilience frameworks which is Disaster Risk Management Cycle (DRMC) is modified and developed to assist the assessment and measurement of community resilient index based disaster risk management phases and sustainability elements. The Community Resilience Index (CRI) approaches was developed to calculate the scores including of Disaster Management Cycle (DMC) (CRI-I), Sustainability (CRI-II), and Overall Dataset (CRI-III). The research goal is to evaluate these three approaches of CRI. About 441 respondent gives their perceptions on the community resilience and disaster readiness for sustainable coastal development in Malaysia. It is discovered that the level of community resilience is high in Mitigation-Prevention (MP) phase of DMC (CRI-I) with a resilience score of 85.7% and followed by social attribute of sustainability (CRI II) with a resilience score of 85.3 %. The overall Community Resilience Index based on the overall dataset (CRI-III) obtained in this study is 85.0%. It is expected that the index produced in this study will help governments at central and local levels to formulate better policies and develop more effective strategies for disaster risk reduction practices.
Computational digital image correlation approaches for structural monitoring applications
(2023-09-01)
Mohammed Abbas Mousa
A picture is worth not only a thousand words, but it can be worth a thousand sensors! The Digital Image Correlation (DIC) technique is an optical, full-field, and non-contact method that employs digital images to measure the two- or three-dimensional components of motion or deformation. The technique is used in many fields, such as solid mechanics, material and structural tests, biology, and others. However, the DIC is prone to errors and limitations that hinder its use in structural tests and applications. These errors and limitations arise from the optical nature of the technique and the complex setup of the tested structural elements. The errors generated from external and internal sources include camera and specimen movement, poor speckle patterns, and random image noise. Therefore, several computational approaches have been applied to 2D-DIC in the literature, like image pre-processing and post-processing of the DIC data. These approaches were assessed through three laboratory experiments of glass and concrete elements and two field tests of concrete structures involving shear wall and bridge pier. The out-of-plane deflection results of the glass sheet are within a 7% difference between the dial gauge and 2D-DIC readings. Similarly, the shear-wall experiment showed that the strain gauge values were within a 7% difference from the in-plane strain data provided by 2D-DIC. Then, it is demonstrated that the Pixel Average (PA) approach enhanced the accuracy of the 2D-DIC data by reducing the variations (S2) of the concrete arches differential strain Diff(εx) up to 90%. Also, the coefficient (R2) improved from 0.45 to 0.9 when ten to twenty averaged images were used. Also, the Image Erode (IE) yielded improved speckle quality with a uniformly high surface component. The concrete arches bending test results show that the crack location was automatically detected and measured. Also, the probability of the cracked section shows a higher possibility of cracking (57% - 76%) respectively at (25% - 50%) of the cracking load compared to (8% - 60%) possibility of cracking of the uncracked sections at the same loading range. Finally, the long-term monitoring of crack width expansion in the bridge pier is almost (0.01mm) when the temperature rises (6 °C). In addition, the crack measurement from the DIC and the demec gauges were compared, and equivalent crack expansion values were found to be (0.004 -0.005)mm for both the DIC and the demec measurements. The results of the experiments show that the 2D-DIC, with the help of computational approaches, can be a reliable monitoring tool.
Correlations between the spt-N value and undrained shear strength for alluvium soil
(2022-09-01)
Tan, Jia Jun
Standard Penetration Test (SPT) is one of the most popular and common in-situ dynamic soil penetration testing methods used to determine the shear strength properties of soils. There are several empirical correlations between the SPT blow count value (SPT-N) and undrained shear strength (Su) of fine-grained soils. However, no available empirical correlations are established for the alluvial soils. Only a limited number of correlations were previously developed for certain soil groups (e.g., residual soil) at specific locations, with uncertain prediction accuracy for different soil groups and ground conditions, particularly in the alluvium formation. With that, this study aimed to evaluate the applicability of SPT in estimating the Su of fine-grained alluvial soils. A total of 234 pairs of SPT-N and Su were collected from previous soil investigation works in Penang Island, Malaysia. After the data screening process, 98 pairs of SPT-N and Su were employed to derive new predictive equations using simple linear regression. New predictive equations were developed according to type, plasticity, and geological origin of the studied soil data. The simple linear regression results revealed the significance of type and geological origin of the studied soil data in influencing the correlation between SPT-N and Su. This study proposed two newly developed equations, and comparisons were made with the studied soil data and correlation equations from previous studies. This study evaluated the prediction capability of the proposed equations and previous studies using graphical analysis (scatter diagram) and statistical analysis like absolute average relative error (AARE) and standard deviation (SD). The proposed equations were found to be reliable in estimating the Su of the fine-grained soils (AARE= 0.29 to xix 0.31, SD= 0.31 to 0.36). For previous studies, the results showed a more noticeable deviations between the soil data and predicted values (AARE= 0.60 to 0.65, SD= 0.31 to 0.41), signifying that the correlation equations may have underestimated or overestimated the shear strength values. The two newly proposed equations were also compared and validated with soil data of outside Penang Island, and these equations showed good reliability. In addition, this study investigated the effect of SPT corrections on the relationship between SPT-N and Su. When the corrections were applied to the SPT-N, for the previous published correlations, the AARE and SD increased by up to 46.5% and 70.73%, respectively. This research also provided new insights into the influence of each correction factor (borehole diameter, sampling method, and SPT hammer energy ratio) as well as the performance of existing correlations. The results revealed that the SPT hammer energy ratio correction was the most significant factor in influencing the relationship between SPT-N and Su. The study’s findings on the prediction capability of the empirical shear strength correlations for the purpose of geotechnical designs were expected to benefit the construction industry.
Cost analyses for earthquake resistant reinforced concrete buildings based on the Malaysian National annex to eurocode 8
(2022-06-01)
Faisal, Farhanah
In Malaysia, the existing reinforced concrete (RC) buildings were designed by considering gravitational loads only. As such, some of this buildings experienced damages when subjected to dynamic loads from the local earthquakes. The 2015 Ranau earthquake is seen as a catalyst for Malaysian construction sector to accelerate the full implementation of seismic design in accordance with the published Malaysia National Annex (NA) to Eurocode 8 (EC 8) in 2017. However, the effect of seismic design consideration on the cost of construction materials for new buildings need to be investigated beforehand to provide information on economic implication to the stakeholders and contractors. Therefore, this study is conducted to estimate therequired material cost in term of concrete and steel reinforcement between non-seismic and seismic design. In this study, six models of 1, 3, 5, 9, 10 and 12-storey had been analysed under different soil types and designed for medium ductility class (DCM) with 0.16 g of peak ground acceleration (PGA) based on contour map in Malaysia NA 2017 as the existing RC buildings were assumed to be in Ranau, Sabah. The results showed that the percentage increase in the total cost of concrete for RC buildings with seismic design was in the range of 4% to 191% compared to the corresponding RC buildings designed without considering the seismic effects. Meanwhile, the percentage difference in the total cost of reinforcement for RC buildings between non-seismic and seismic design was in the range of 11% to 318%.

Browse

Browsing Pusat Pengajian Kejuruteraan Awam - Tesis by Title

Results Per Page

Sort Options