MERCon - 2022
Permanent URI for this collectionhttp://192.248.9.226/handle/123/18494
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Browsing MERCon - 2022 by Author "Amarasinghe, DAS"
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- item: Conference-Full-textDirect current resistivity based in-situ cure monitoring technique for amine cured epoxy resins(IEEE, 2022-07) Herath, HS; Janith, GI; Weragoda, VSC; Amarasinghe, DAS; Attygalle, D; Samarasekara, AMPB; Rathnayake, M; Adhikariwatte, V; Hemachandra, KThe Epoxy resins and epoxy resins-based system usage in industrial applications such as composites and electronic materials keep growing. Thus, research focused on enhancing the properties of these resin-based systems is of importance for manufacturing quality controls. Especially monitoring of cure progression and chemo-rheological behavior of epoxy resins are essential for many industries. Commonly practiced cure monitoring methods such as DSC and DMA for the purpose are conducted in laboratories under specified conditions and are not practiced for real-time cure monitoring. However, in-situ cure monitoring techniques are essential for many industries as they provide more insight and thus more control over processing parameters. This study introduces a direct current resistivity-based cure monitoring method as it is simple, cost-effective, reliable, and more importantly, industry-friendly. The fast response of direct current measurements combined with the simplicity of the analysis makes this method suitable for real-time sensing applications. The strong correlation between the degree of cure and the viscosity allows us to take simultaneous measurements of both. The method's feasibility was analyzed using two amine cured epoxy resin systems.
- item: Conference-Full-textThe effect of surface topology on the edl capacitance: 1_d case(IEEE, 2022-07) Amarathunga, AAS; Malshan, LPJ; Amarasinghe, DAS; Attygalle, D; Rathnayake, M; Adhikariwatte, V; Hemachandra, KAn electrical capacitor is an energy storage device that generates an electric field between electrodes and produces potential that can be channeled through associated circuits. The Electrical Double Layer (EDL) capacitor is a unique capacitor with a remarkably higher capacity. The energy densities of these capacitors can range between 0.5 and 10 Wh/kg. This study develops a method to predict the dependence of the double-layer capacitance on the roughness profile of the electrode using the linear Poisson-Boltzmann theory, and the Gouy-Chapman theory for 1-D systems. The roughness dependence of diffuse layer differential capacitance is obtained for a defined roughness profile. The theory developed here helps to understand the Debye-length dependent on the roughness factor and profile. The variation of double-layer capacitance with roughness is analyzed based on a numerical solution obtained for the model roughness profile.
- item: Conference-Full-textMie-theory-based investigation of the effect of size distribution on the surface plasmon absorption of silver nanoparticles(IEEE, 2022-07) Weerasekera, RAADO; Samarakoon, DMLY; Dayalal, DLHPP; Amarasinghe, DAS; Samarasekara, AMPB; Rathnayake, M; Adhikariwatte, V; Hemachandra, KThe surface plasmon absorption of metallic nanoparticles is of great interest due to their wide range of applications, predominantly with optical technology. Therefore, a reliable plasmon spectrum analysis tool would greatly value the researchers working in this area. Mie theory-based theoretically computed spectrum generating tools are used in the literature to analyze the surface plasmon absorption of monodisperse particles. However, none of them can accommodate size distribution contributions. As monodisperse nanoparticle dispersions are practically impossible to achieve in synthesis, incorporating the particle size distribution effect into the surface plasmon analysis tools makes them more reliable. In this study, we investigated the effect of particle size distribution on the surface plasmon absorption bands of silver nanoparticles suspended in water. Mie theory-based simulations were performed for different particle sizes ranging from 1 to 40 nm and for different size distributions. The maximum absorbance, peak position, and full width at half maximum (FWHM) variations with respect to particle radius were analyzed.
- item: Conference-Full-textModeling the mechanical behavior of microcrystalline cellulose-based polymer composite materials(IEEE, 2022-07) Amutheesan, J; Sukirtha, S; Samarasekara, AMPB; Amarasinghe, DAS; Karunanayake, L; Rathnayake, M; Adhikariwatte, V; Hemachandra, KPolymer-based composite materials are used in many engineering applications. There is an increasing demand for environment-friendly reinforcing materials in the industry. Previous studies done in this laboratory suggested that microcrystalline cellulose-based composite has better properties such as tensile strength, elastic modulus, stiffness, water absorption, and thermal stability. The property optimization solely through an experimental approach costs a lot of time and resources. However, if a reliable model can be developed to explain the composition property relationship, the cost can be significantly reduced. A simple rule of mixture-based models does not adequately explain the variation of mechanical properties with the composition. This paper discusses a modified form of a mathematical model based on a rule of mixture principles to predict the mechanical behavior of microcrystalline cellulose-based polymer composites. The model aims to predict the mechanical property variation of Microcrystalline cellulose (MCC) reinforced composites. Theoretical values obtained from the developed model were compared with the experimental values obtained from the fabricated composites. The results show good agreements, confirming the potential of the mathematical model.
- item: Conference-Full-textA novel method on fitting a short prony series using creep or stress relaxation data(IEEE, 2022-07) Janith, GI; Herath, HS; Amarasinghe, DAS; Attygalle, D; Weragoda, VSC; Samarasekara, AMPB; Rathnayake, M; Adhikariwatte, V; Hemachandra, KThe time dependent viscoelastic properties such as creep and stress relaxation are very important properties to be considered when designing with viscoelastic materials working at high temperature or extreme conditions. Mechanical models consisting of springs and dashpots are used to model these time dependent properties. Determining these models is done by fitting a Prony series to experimental creep or stress relaxation data. Most of the Finite Element Analysis softwares that are capable of viscoelastic modeling also uses Prony series to characterize such a material. Therefore, it is useful to have a fast, simple, and mathematically less cumbersome method to fit such a Prony series. The novel method introduced in this paper can be used to fit a short Prony series and makes the process much simpler and faster.
- item: Conference-Full-textStudy on thermal endurance of plasticizer in locally manufactured electrical cable insulation(IEEE, 2022-07) Egodage, DP; Dodampola, R; Ratnakumar, A; Weragoda, SC; Amarasinghe, DAS; Samarasekara, AMPB; Attygalle, D; Rathnayake, M; Adhikariwatte, V; Hemachandra, KElectrical cables are collections of one or more electrical conductors, which are separately insulated and covered together using a sheathing material. Since air does not perform well as a good insulation material, an insulation material is also introduced to resist the passing of electrical current in the radial direction. This will prevent electrical leakage and protect the stability of wire material by concealing it from environmental attacks such as heat and humidity. This paper analyzes the kinetics of the thermal endurance of plasticizers present in locally available electrical cable insulations. For this purpose, a model was developed to map higher temperature accelerated plasticizer evaporation kinetics to lower temperature practically experiencing values. Plasticizer evaporation data were collected in the range of 80-160 °C. Since the plasticizer evaporation reaction occurs over the considered temperature range, notable physical transitions (e.g., crystallization or glass transition) were not observed within the mentioned temperature range. Therefore, The Arrhenius-principle-based approach was employed to map accelerated condition measurements to ambient condition evaporation. An Experimentally determined evaporation behavior was used to define the evaporation kinetics of plasticizers. It was observed that the rate constant of plasticizer evaporation increases with the increasing temperature.