MESII - 2023

Permanent URI for this collectionhttp://192.248.9.226/handle/123/21214

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item: Conference-Abstract
Activated graphene oxide for removal of methylene blue from wastewater
(Department of Materials Science and Engineering, University of Moratuwa., 2023-07-28) Raveena, LAL; Viraji, HA; Rathnayake, RMSL; Sitinamaluwa, HS; Sivahar, V
Lately, activated oxidized graphene has sparked a lot of attention in the fields of wastewater treatment and water filtration. Here, the possibility for using activated graphene oxide (AGO) to remove methylene blue (MB) from water systems was investigated. Commercially available Graphene Oxide (GO) was obtained, and it was further modified by alkali-activation method to obtain AGO. The resulting AGO was tested as an adsorbent for methylene blue removal. Activation time was varied to optimize the MB removal of the adsorbent and then the adsorbents were characterized by using FTIR, SEM, BET and XRD analysis. Synthesized AGO shows prominent MB adsorption characteristics due to H-bonding, and electrostatic interactions. To evaluate the adsorption capacity, batch adsorption experiments were carried out and the effect of pH and temperature on dye adsorption were investigated. Maximum adsorption capacity of 123.47 mg/g was obtained for AGO sample which was activated for 1.0h and the data were well fitted to Langmuir isotherm model. These findings demonstrate the possibility for cationic dye removal from wastewater systems using an economically viable AGO.
item: Conference-Abstract
Design and simulation of solid state micropump based on piezoelectric actuator
(Department of Materials Science and Engineering, University of Moratuwa., 2023-07-28) Sivahar, V
This research presents the design and simulation of a solid-state insulin micropump based on a piezoelectric actuator for a wearable insulin pump device to be used on the human body. The primary objectives of this design are to minimize the need for frequent dosing, replace oral therapy, and alleviate the discomfort associated with painful injections for individuals with diabetes. Our research provides an overview of key concepts, the operating principle, and the design considerations of the micropump. The selection of materials, theoretical studies, and the optimization process of the pump were also investigated in our research. Finite element analysis was employed to optimize the design, and the simulations were conducted using COMSOL Multiphysics 5.3a software in the research. By utilizing the piezoelectric actuator, the proposed micropump demonstrates promising potential for reasonable insulin delivery. The simulations enable the evaluation of various parameters such as actuator performance, fluid flow dynamics, and overall flowrate. The results obtained from the simulations provided valuable insights into the overall performance of the pump and aid in its refinement. The integration of wearable insulin pump devices with this micropump design opens new possibilities for convenient and effective diabetes management.
item: Conference-Abstract
Development of a computer software for polymer composite mechanical properties analysis
(Department of Materials Science and Engineering, University of Moratuwa., 2023-07-28) Mudalige, SP; Sanjeewa, PVGI; Weragoda, VSC; Sivahar, V
This research investigates the development of a software application designed for the analysis of polymer composites and the estimation of their mechanical properties, specifically the elastic modulus and tensile strength. In response to the need for accessible and efficient computer applications in composite analysis, this study focuses on developing a software which employs scanning electron microscopy (SEM) micrographs of the composites to extract relevant data. The software utilizes image processing techniques to accurately identify spherical particles within the composite and offers estimations for the elastic and shear modulus as well as tensile strength values. It is particularly suitable for the analysis of composites consisting of randomly oriented spherical particles, as well as those reinforced with short fibers. The mathematical models employed in the software, derived from previous calculations, allow for the estimation of the elastic modulus, shear modulus, and Poisson's ratio of the composite. The software also provides additional features to enhance its reliability and user experience. Furthermore, to ensure accuracy and reliability, the software underwent validation by comparing its predictions against literature-based real values. The developed software application addresses the need for accessible and efficient computer applications in the field of mechanical data extraction from polymer composites. It offers a user-friendly interface and advanced algorithms for analyzing SEM micrographs and extracting key mechanical properties quickly and efficiently. The software provides researchers and engineers with a valuable tool for efficient analysis and characterization of composite materials, contributing to advancements in the field of composite research.
item: Conference-Abstract
Development of an exhaled breath analyzer for early detection of diseases
(Department of Materials Science and Engineering, University of Moratuwa., 2023) Panawala, PSS; Tissera, PIU; Amarasinghe, DAS; Sivahar, V
Chronic Kidney Disease (CKD) represents a significant global health burden, with early detection being crucial for effective management and improved patient outcomes. This research focuses on the development of an Exhaled Breath Analyzer (EBA) as a non-invasive and potentially cost-effective tool for early detection of CKD. Ammonia (NH3) has been identified as a key marker in exhaled breath to diagnose CKD patients as the concentration of ammonia among healthy people is about 0.5-5 ppm and in CKD patients it can be more than 25 ppm. In this work, an ammonia gas sensor based on Polyaniline (PANI) was fabricated using a custom made Interdigitated capacitive sensor (IDC-S). PANI films were successfully deposited on the IDC-S using the solution casting method. The sensor responded to a low ammonia concentration of 50 ppm with a capacitance change of 10% with respect to capacitance in air in room temperature. Furthermore, the response of the sensor increased to 44% as the concentration increased to 300 ppm. This showed a good linear relationship between sensor response and ammonia concentration. Furthermore, the effect of relative humidity on the sensor was also studied and a significant change in capacitance of the sensor was observed with changing relative humidity levels. Moreover, the sensor response to a fixed ammonia concentration of 200 ppm at different humidity levels was studied and it diminished from 26% to 4% as the humidity level increased from 20% to 90%.
item: Conference-Abstract
Development of an exhaled breath analyzer for early detection of diseases
(Department of Materials Science and Engineering, University of Moratuwa., 2023-07-28) Panawala, PSS; Tissera, PLU; Amarasinghe, DAS; Sivahar, V
Chronic Kidney Disease (CKD) represents a significant global health burden, with early detection being crucial for effective management and improved patient outcomes. This research focuses on the development of an Exhaled Breath Analyzer (EBA) as a non-invasive and potentially cost-effective tool for early detection of CKD. Ammonia (NH3) has been identified as a key marker in exhaled breath to diagnose CKD patients as the concentration of ammonia among healthy people is about 0.5-5 ppm and in CKD patients it can be more than 25 ppm. In this work, an ammonia gas sensor based on Polyaniline (PANI) was fabricated using a custom made Interdigitated capacitive sensor (IDC-S). PANI films were successfully deposited on the IDC-S using the solution casting method. The sensor responded to a low ammonia concentration of 50 ppm with a capacitance change of 10% with respect to capacitance in air in room temperature. Furthermore, the response of the sensor increased to 44% as the concentration increased to 300 ppm. This showed a good linear relationship between sensor response and ammonia concentration. Furthermore, the effect of relative humidity on the sensor was also studied and a significant change in capacitance of the sensor was observed with changing relative humidity levels. Moreover, the sensor response to a fixed ammonia concentration of 200 ppm at different humidity levels was studied and it diminished from 26% to 4% as the humidity level increased from 20% to 90%.
item: Conference-Abstract
Development of cost-effective cement-based ceiling sheet with the addition of waste foundry dust
(Department of Materials Science and Engineering, University of Moratuwa., 2023-07-28) Mathuran, T; Thulaanchan, K; Fernanado, TN; De Silva, GIP; Sivahar, V
Ceiling sheets are predominantly produced with the addition of asbestos; however, asbestos has been identified as a carcinogenic material. Hence, there is pressing demand for alternative materials to produce ceiling sheets. Waste Foundry Dust (WFD) is a byproduct of metal sand casting process, and there is no effective permanent solution for disposal of the WFD. In this study, the possibility of manufacturing cement-based ceiling sheets with addition of WFD is investigated as a low cost and healty alternative for asbestos based ceiling sheets. Firstly, Ordinary Portland Cement (OPC) was mixed with WFD amount of 30%, 40%, 50% & 60% of total weight to prepare the material. Then, sheets were prepared using compression molding, by applying 2 tons per inch pressure. Also, another set of samples were made by replacing 3 wt% of cement with bentonite, with the same WFD amounts. A series of experiments were conducted to measure flexural strength, thermal conductivity, and water absorption of the prepared samples after 28 days of curing period. All the sample preparations and testing were done according to ASTM C-1185 standard. The results show that the strength and thermal conductivity decrease with increase of WFD while water absorption increase with increasing WFD. Here bentonite is used as binder to increase the binding property, hence improve the properties of prepared samples. WFD mainly acts as filler material to reduce the cost and reduce the adverse effect on environment.
item: Conference-Abstract
Development of engine oil quality analyzer based on optical metrological techniques
(Department of Materials Science and Engineering, University of Moratuwa., 2023-07-28) Ishan, RLP; Heshan, MPN; Attygalle, D; Sivahar, V
With an annual global consumption of 36.3 million tons of engine oil and concerns about premature disposal, we propose an optical metrological approach to accurately assess engine oil quality. A side polished optical fiber in touch with oil, photo diode and a photo detector were used to build the sensor unit. To avoid damage to the core, cladding removal was performed meticulously, while minimizing wire bending reduced optical power loss. Utilizing a side-polished optical fiber, the refractive index changes in engine oil were measured, allowing real-time assessment. This method offers non-destructive, precise, and straightforward measurements. Theoretical validation was done by utilizing Fresnel's equations. Further a correlation between theoretical values and refractive indices of oils with mileage was established. For the oil type 10W-30, which is used as the engine oil for petrol engines, a change of refractive index of 1.4651 to 1.4689 was observed over a milage of 3140 km. the detector voltage ratio for that range was 0.5928 to 0.6748, which is well within the range the sensor can detect. Similarly, an experiment conducted for oil type 15W-40, which is an engine oil used in diesel engine showed a refractive index variation of 1.5966 to1.6015 over a milage of 3721 km, which corresponds to a change of sensor voltage ratio 0.5427 to 0.4571 was obtained. Both experimental data and theoretical predictions confirmed that the sensor is effective and sensitive to subtle change in oil quality. This research successfully developed optical metrology, offering potential for online oil quality monitors, and addressing environmental concerns linked to premature oil disposal.
item: Conference-Abstract
Development of new bio-based adhesive for paper/cardboard
(Department of Materials Science and Engineering, University of Moratuwa., 2023-07-28) Dileepa, KDR; Uresh, KA; Udayakumara, SV; Sivahar, V
Bio-based adhesives are derived from renewable resources such as plant-based materials, animal by-products, and microbial sources. Latex-based bioadhesives, specifically those made from natural latex derived from plant sources, have garnered significant research interest. While natural rubber remains the most commonly used biosource for latex adhesives, this study explores the potential of alternative plant sources that produce latex. In particular, it provides a review of Pterocarpus indicus latex and discusses modifications made to enhance its adhesive properties. Additionally, this research examines the effect of additives such as Polyvinyl Alcohol on the adhesive properties of natural latex while evaluating their capacity for adhesive performance. The major challenges faced by existing bio-based adhesives, including low bonding strength and water resistance are acknowledged. Consequently, this study offers guidance on advancing new plant sources for bio-based adhesives, addressing the limitations of current adhesive products.
item: Conference-Abstract
Development of shape memory polymer for high temperature applications
(Department of Materials Science and Engineering, University of Moratuwa., 2023-07-28) Koralage, CR; Srilal, TAB; Samarasekara, AMPB; Sivahar, V
Cyanate ester (CE) based polymers are well known for aerospace and microelectronic applications due to their unique characteristics at higher temperatures. Due to the cyanurate network formed during the curing process, cyanate ester-based shape memory polymers have resistance to harsh environment conditions. Furthermore, the shape memory behaviour of CE based resins allows them to be a suitable candidate for high temperature applications which require shape memory effect. This study investigates the shape memory behaviour of bisphenol-A-cyanate ester (BACE) cured with polyethylene glycol (PEG) with five different ratios. The formation of cyanurate has been confirmed by the Fourier transform infrared spectroscopy (FTIR) analysis. The thermal stability of the developed material was confirmed using the Differential Thermal Analysis (DTA)/ Thermogravimetric analysis (TGA). It was confirmed that thermal stability remains up to 350 C0. The shape memory behavior was successfully performed by the polymer with shape memory bending test. The modified resin with higher PEG ratios indicates higher shape recovery ratios whereas the resins with lower PEG ratios exhibit higher shape fixity ratios, tensile strengths, and hardness values. Using PEG as the switching segment, CE based resins can be used for high temperature shape memory applications and can be modified to obtain certain properties according to the PEG ratios.
item: Conference-Abstract
Development of tire strain measurement sensor
(Department of Materials Science and Engineering, University of Moratuwa., 2023-07-28) Adhikari, AAMBW; Dissanayake, DMAGI; Weragoda, VSC; Sivahar, V
This research investigates engineering of a tyre strain measurement sensor using elastomer based conductive polymer. This sensor allows monitoring the changes in vehicle tyre strain in real time. This information can be interpreted in terms of tyre performance relevant to driving safety, fuel economy and passenger comfort. An elastomeric sensor was proposed to cope with the relatively high strains expected together with the requirement to withstand a large number of flexing cycles. A Styrene butadiene rubber compound was used with conductive carbon black added to a sufficient quantity to overcome the percolation threshold of the compound. Over 10% of conductive carbon black was used in creating the compound and it was tested on a special rig to ascertain adequate response of electrical conductivity change with respect to the applied strain. According to the results most suitable range of strain was selected and a mould for the sensor was designed with sufficient dimensions to compensate for the difference in optimum strain range of the compound against the expected strain range of the tyre. The threshold concentration was chosen for the development of the sensing part due to its high sensitivity to strain. The sensor is to be applied between inner surface of the thread and wall of the vehicle tyre. Sensor part will be stretched or relaxed when deformations occur on the tyre. A circuit is designed to detect changes in resistivity within the sensing part, which directly correlates with the strain experienced by the vehicle tyre. By measuring these resistances, real-time road conditions can be determined. Based on these conditions, the driver will receive appropriate safety warnings.
item: Conference-Abstract
Dynamic mechanical analysis of elastomers
(Department of Materials Science and Engineering, University of Moratuwa., 2023-07-28) Bhashana, BTA; Weerasena, KMWK; Weragoda, VSC; Sivahar, V
Dynamic Mechanical Analysis (DMA) indeed plays a significant role in both research and quality control processes, especially in the field of materials science and engineering. DMA allows researchers and manufacturers to study the viscoelastic properties of materials, such as polymers, composites, rubbers, and biomaterials, under various conditions like temperature, frequency, and strain. However, the high cost of traditional DMA equipment can be a limiting factor for its widespread adoption, particularly for researchers and manufacturers with budget constraints. To address this limitation, we initially introduced low-cost DMA equipment capable of handling larger sample sizes, specifically designed for conducting frequency sweep and compression mode tests, to enhance the quality control process in the tire industry in Sri Lanka. In a frequency sweep test conducted in a strain-controlled dynamic mechanical analysis (DMA) setup, several parameters can be measured to characterize the viscoelastic behavior of the material: Loss tangent, relaxation time, storage modulus (E'), loss modulus (E’’), molecular weight distribution, damping properties (damping coefficient).
item: Conference-Abstract
Effect of process parameter on the extraction of nano CaO powder from eggshells
(Department of Materials Science and Engineering, University of Moratuwa., 2023-07-28) Weerakoon, WAKN; Udawala, RDNSS; Galhenage, AS; Sivahar, V
In recent years, the use of nanoparticles as fertilizers has gained significant attention due to their unique physicochemical properties and their ability to enhance plant growth and productivity. The extraction of nano CaO from eggshells waste to synthesize nano fertilizer represents a pioneering advancement in sustainable development, agriculture, and nano technology. As waste reduction and sustainable resource management emerge as crucial priorities for an environmentally conscious and resource-efficient society, the effective utilization of waste materials becomes imperative, offering opportunities to extract valuable resources while minimizing environmental impact. In this study, CaO nanoparticles were synthesized by the thermal decomposition and grinding of eggshell waste. The effect of synthesis process variables, namely, the grinding method (dry milling, wet milling), the grinding time, the calcination time, and the calcination temperature was investigated. Egg shell powder as well as synthesized CaO were characterized using TGA, SEM, XRD and FTIR. The highest CaO yield, and reduced particle size were given with wet milling for 1 hour followed by calcination at 900°C for 3 hours.
item: Conference-Abstract
Estimation of weibul modulus through ultrasonic measurements
(Department of Materials Science and Engineering, University of Moratuwa., 2023-07-28) Rangajeewa, GLJ; Dewaraja, MM; Sivahar, V; Sivahar, V
This research explores non-destructive ultrasonic measurements to estimate the Weibull modulus of glass, a key parameter for assessing its strength and reliability. Glass's unique properties make it widely used in various industries, but its brittleness and potential for catastrophic failure in critical applications necessitate accurate characterization methods. Traditional mechanical testing methods for Weibull modulus are costly and time-consuming. The study demonstrates that ultrasonic measurements offer a reliable and accurate alternative. Results obtained from ultrasonic measurements strongly correlate with conventional methods. The implications extend to industries like automotive and aerospace, where glass components play vital roles. Ultrasonic measurements can optimize design processes, ensure product reliability, and enhance safety. This cost-effective and efficient technique holds promise for quality control during glass component manufacturing, contributing valuable insights to advance the understanding and utilization of glass in diverse applications.
item: Conference-Abstract
Extraction of natural dyes from leaves of coffea arabica and its application in cotton fabrics
(Department of Materials Science and Engineering, University of Moratuwa., 2023-07-28) Rajakaruna, RMMS; Rathnayaka, RMJCB; Udayakumara, SV; Sivahar, V
This study explores the extraction of natural dyes from the leaves of Coffea arabica trees (coffee leaves) to investigate their application on cotton fabrics. The objective is to evaluate the viability of using these natural dyes as a sustainable alternative to synthetic dyes in the textile industry. Three different mordanting techniques and different mordents were employed to dye treated and untreated cotton fabrics. The results indicate that the pre-mordanting technique yielded the best dye adhesion to the cotton fabrics. Moreover, the cotton samples treated with tannic acid displayed improved washing and perspiration-fastness properties compared to the untreated fabrics. Colour coordinate values were measured using a data colour spectrometer, and a preliminary comparison was conducted to assess the dye's anticipated colours and colour intensities. Overall, this study sheds light on the potential of natural dyes derived from Coffea arabica leaves as a sustainable substitute for synthetic dyes in the textile industry. The findings contribute to advancing eco-friendly practices and promoting environmentally conscious choices in textile manufacturing.
item: Conference-Abstract
Influence of particle size and crystallite size on hydroxyapatite nanoparticle degradation in pbs
(Department of Materials Science and Engineering, University of Moratuwa., 2023-07-28) Anjana, JY; Arachchi, DHR; Adikary, SU; Sivahar, V
In this study, we investigate the influence of particle size and crystallite size of Hydroxyapatite nanoparticles, synthesized using the wet chemical precipitation technique on degradation in Phosphate Buffer Saline (PBS). Different concentrations of calcium hydroxide and orthophosphoric acid were used for the synthesis process to achieve different supersaturations. The Ca/P molar ratio was kept at 1.67 while changing the supersaturation. The synthesized nanoparticles were characterized using a laser particle analyzer, Scanning Electron Microscope (SEM), X-ray diffractometer (XRD), Energy Dispersive X-Ray Analysis (EDAX), and Fourier- Transform infrared (FT-IR) spectroscopy to study their size, morphology, structure, and composition. The study demonstrated that controlling the precursor concentrations to induce varying supersaturation levels allows for the modulation of particle size and crystallite size of Hydroxyapatite nanoparticles, subsequently affecting the degradation behavior of HA, which is dependent on the particle size.
item: Conference-Abstract
Materials Engineering Symposium on Innovations for Industry 2023 (Pre Text)
(Department of Materials Science and Engineering, University of Moratuwa., 2023-07) Sivahar, V
item: Conference-Abstract
Measurement of effective heat transfer in elastomers with laser flash instrument
(Department of Materials Science and Engineering, University of Moratuwa., 2023-07-28) Karunathilaka, KM; Mihiranga, SKU; Weragoda, VSC; Sivahar, V
The aim of this project is to design a low-cost laser flash instrument for measuring the effective heat transfer in elastomers. Heat transfer in elastomers primarily occurs through conductivity, and various methods can be employed to measure thermal conductivity. However, considering the time-consuming nature of these methods, the laser flash instrument proves to be the most suitable option to be used for industrial applications. This project proposes the use of halogen lamps as a heat source, an IR detector to obtain temperature data, and a NodeMCU acting as a server to transmit recorded temperature data for further processing. The data will be used to calculate the thermal diffusivity and thermal conductivity based on the rate of temperature rise of the test specimen after the application of a heat pulse. Instrument was calibrated using specimens of material with known thermal conductivity and thermal diffusivity.
item: Conference-Abstract
Modelling and simulation of nanogenerator using vertically integrated zinc oxide nanowire array
(Department of Materials Science and Engineering, University of Moratuwa., 2023-07) Samaraweera, RLU; Buddhima, LHP; Adikary, SU; Sivahar, V
Recent developments in nano-level energy harvesting are mainly focused on using piezoelectric power generators from compression and vibration modes. In this work, a vertically integrated zinc oxide piezoelectric nanowire array was modeled to scavenge energy from low-frequency compression force. COMSOL Multiphysics 5.4 software was used to simulate and model nanowire array structures to ensure the potential distribution and overall electric energy generator of the piezoelectric structure under compression displacement. Piezoelectric constitutive equations were used to develop mathematical equations in terms of comparing and confirming induced piezoelectric outputs. The simulation results confirmed that the voltage output of the nanowire array does not depend on the number of nanowires. Total electric energy harvested by the array depends on the number of nanowires and nanowire density.
item: Conference-Abstract
Monitoring of fiber reinforced polymer degradation with ultrasound
(Department of Materials Science and Engineering, University of Moratuwa., 2023-07-28) Sinthujan, K; Sivahar, V; Sivahar, V
This research focusses on monitoring the degradation of Fiber Reinforced polymer (FRP) composites using ultrasonic testing. The study aims to assess the impact of ultraviolet (UV) radiation on FRP materials and establish a correlation between ultrasonic wave velocity, attenuation, and mechanical properties. Five FRP samples, fabricated according to ASTM D638 standard dimensions, are subjected to different UV exposure durations, are subjected to different UV exposure durations. Ultrasonic measurements are conducted before and after degradation to detect changes in wave velocity and attenuation. Tensile testing is performed to evaluate the sample’s mechanical properties. The results show how ultrasonic testing can effectively identify degradation in FRP composites and provide insights into their lifespan under UV exposure. The research contributes to understanding degradation mechanisms and optimizing maintenance strategies for FRP composite structures.
item: Conference-Abstract
Numerical optimization of band gap gradient cigs solar cells
(Department of Materials Science and Engineering, University of Moratuwa., 2023-07-28) Sewwandi, HMDU; Amanda, WN; Attygalle, D; Sivahar, V
Thin-film chalcopyrite Cu(In1-x, Gax)Se2 (CIGS) Solar cells have become more promising for commercial applications due to recent laboratory advancements, achieving an efficiency of approximately 22%, which surpasses efficiencies most other thin-film solar cells. This study of numerical device simulations has proposed methods to improve the efficiency of thin film CIGS solar cells and analyze the composition gradient shift due to In, Ga diffusion under solar cell fabrication conditions. In CIGS solar cells, the Cu(In1-xGax)Se absorber layer is the most critical layer that influences the solar cell performance. In this simulation study, several band gap gradients were created by varying compositional ratio of Ga to In in the absorber layer. The band gap gradient optimization was done by using numerical device simulator SCAPS software. The optimum bandgap gradient slope of 0.61 eVμm-1 was obtained with the improved efficiency of 32% and a fill factor of 88.5. The diffusion of In and Ga under fabrication conditions were simulated by COMSOL MULTIPHYSICS software. Taking account of compositional variation of the absorber due to diffusion, the optimum conversion efficiency has dropped to 25%. The simulation results obtained for solar cell performances and elemental gradients reported for high efficiency solar cells shows a good agreement. Considering the effect of diffusion at elevated temperatures during fabrication, this study proposes an optimum elemental flux to be used fabrication of graded band gap CIGS layer.

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