Gehan Amaratunga

Gehan Amaratunga
University of Cambridge | Cam · Department of Engineering

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829
Publications
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32,115
Citations

Publications

Publications (829)
Article
Full-text available
We propose a computational design framework to design the architecture of a white lighting system having multiple pixelated patterns of electric-field-driven quantum dot light-emitting diodes. The quantum dot of the white lighting system has been optimised by a system-level combinatorial colour optimisation process with the Nelder-Mead algorithm us...
Article
A highly controllable, green, and rapid strategy is demonstrated for fabricating of highly sensitive non-enzymatic glucose sensing platforms. Carbon nanohorns (CNHs) were decorated onto the screen-printed electrodes. Binary nickel-cobalt sulfide (NiCo-S) nanosheets (NSs) were then deposited on CNH-casted electrodes by a facile and scalable method....
Article
Various dyeing techniques are utilised at dyeing different types of fabrics and current study discuss the possibility of using a single dye bath for the given purpose. The current study utilised a radio frequency glow discharge plasma source maintained at near atmospheric conditions (around 200 mbar) in nitrogen and air environments to treat cotton...
Preprint
In a time where global agricultural stability is facing unprecedented challenges due to growing population, climate change, and emerging pandemics, the development of advanced organic-inorganic functional nanohybrids as advanced fertilizers could contribute significantly to meeting these challenges. They hold the potential of reducing overall ferti...
Article
Full-text available
Smart textiles consist of discrete devices fabricated from—or incorporated onto—fibres. Despite the tremendous progress in smart textiles for lighting/display applications, a large scale approach for a smart display system with integrated multifunctional devices in traditional textile platforms has yet to be demonstrated. Here we report the realisa...
Article
A nanotechnology based approach to improve the anticancer of XLAspP2-RA, against muscle rhabdomyosarcoma (RD) is reported. The XLAspP2-RA was successfully synthesized, and the structure was confirmed by ¹H NMR spectroscopy. Loading of XLAspP2-RA into APTES modified halloysite nanotubes and Graphene Oxide are confirmed by FT-IR spectroscopy. The enc...
Article
In realistic power system state estimation, the distribution of measurement noise is usually assumed to be Gaussian while many researcher have verified that it can be non-Gaussian. In this paper, a new robust state estimator based on exponential absolute value function is proposed to address the non-Gaussian measurement noise and outliers. The infl...
Article
Even though the noise model applied in power system dynamic state estimation (DSE) is usually assumed to be Gaussian, this is not the case due to the unknown system inputs, influence from the communication channel noise, and the outliers generated by phasor measurement units (PMUs). In this article, a robust power system DSE method combining a robu...
Article
Quantum Dots (QDs) are an emerging class of photoactive material that exhibit extraordinary optical features. Due to the availability of narrowband emitted light from QDs, they can be used to...
Article
Phasor measurement units (PMUs) are becoming more popular in power systems and most of the distributed state estimation methods are based on the Gaussian measurement noise assumption. However, the PMU measurement noise has been demonstrated to be non-Gaussian. This article presents a distributed multiarea state estimation approach based on the quad...
Article
Device architectures of patterned-, stacked-, and mixed-type quantum-dot light-emitting diodes (QD-LEDs) for the next-generation smart white lighting have been analyzed and optimized by computational charge transport simulation and experiments.
Article
In traditional power system state estimation application, the distribution of measurement noise is frequently assumed to be Gaussian. However, the distribution is sometimes unknown in practice and the above assumption may be wrong. In this paper, a totally distributed robust state estimation algorithm considering maximum exponential absolute value...
Article
Beclomethasone dipropionate (1) is a widely used synthetic corticosteroid to treat asthma, allergic rhinitis, and dermatoses. This is so because of its anti-inflammatory, antipruritic, and anti-allergy properties. However, existing synthetic routes to this active pharmaceutical ingredient (API) contain low and inconsistent yielding steps, use of ob...
Article
Progress toward the development of advanced supercapacitor technologies is closely associated with high-performance electrode materials. Carbon-based conductive additives modifying electrode material effectively improves the electronic conductivity and promotes the redox reaction. In this paper, we developed a highly effective binary conductive add...
Article
Uncertainties in renewable energy sources and load demand have become a consequential issue which has led to a significant effect on the microgrid operation. In this paper, a novel cumulative relative regret decision-making strategy is proposed for the optimal energy management on a grid-connected multi-energy microgrid considering these uncertaint...
Article
Full-text available
Distribution system state estimation (DSSE) plays a significant role for the system operation management and control. Due to the multiple uncertainties caused by the non-Gaussian measurement noise, inaccurate line parameters, stochastic power outputs of distributed generations (DG), and plug-in electric vehicles (EV) in distribution systems, the ex...
Article
Full-text available
Propensity of a textile material to evaporate moisture from its surface, commonly referred to as the ‘moisture management’ ability, is an important characteristic that dictates the applicability of a given textile material in the activewear garment industry. Here, an infrared absorbing nanoparticle impregnated self-heating (IRANISH) fabric is devel...
Article
Indoor photovoltaics have attracted considerable attention due to their great potential for powering low‐power electronics and photonic devices under ambient light. Bo Hou, Gehan A. J. Amaratunga and co‐authors (DOI: 10.1002/inf2.12180) provide an overview and prospect of the recent advances in various indoor photovoltaics. Indoor photovoltaics hav...
Article
Full-text available
Indoor photovoltaics (IPVs) have attracted considerable interest for their potential to power small and portable electronics and photonic devices. The recent advancemes in circuit design and device optimizations has led to the power required to operate electronics for the internet of things (IoT), such as distributed sensors, remote actuators, and...
Article
This paper investigates how to add a limited number of Phasor Measurement Units (PMUs) to the existing monitoring system so as to improve the estimation accuracy further. The existing methods are usually based on Gaussian noise assumption and the weighted least squares (WLS) estimator is taken into account. However, the Gaussian noise assumption is...
Article
Full-text available
Synthesis of ultrathin heterostructures has received much attention in the recent past due to their unique physical and chemical properties. In this work, we report the synthesis of Fe2TiO5-TiO2 heterostructures using a simple hydrothermal technique employing natural ilmenite as the source. Hierarchically arranged nanostructures with interconnected...
Conference Paper
Full-text available
Worldwide, urea remains the most widely used nitrogen fertilizer contributing to global food security. However, 70 80% of urea is lost during fertilization. Therefore, solutions for increasing its plant availability while reducing adverse effects to the environment caused by eutrophication and increase in greenhouse gases are of major importance in...
Article
Synthesis of Levothyroxine sodium, the sodium salt of a synthetic levoisomer of thyroxine, revolutionized the management of hypothyroidism and related symptoms. However, the main synthetic route to this active pharmaceutical ingredient (API) is more than 70+ years old with low-yielding steps, obsolete reagents, and lacks experimental data on interm...
Article
A unique zirconia nanomorphology possessing an enhanced photocatalytic efficiency was developed utilizing a convenient single-sol synthesis process which involved in-situ doping of zirconia by boron at the sol stage. The boron-doped zirconia exhibited a flake morphology as opposed to the spherical pure form and subsequent crystallographic investiga...
Article
Full-text available
In order to advance the thin film silicon solar cell technology, it is desirable to replace the layers of doped thin film silicon or its alloys with alternative materials that can be deposited by simple physical vapor deposition (PVD) methods. Here, a dopant free a-Si:H solar cell design of Asahi U substrate | MoOx | a-Si:H | LiF | Al is investigat...
Article
Full-text available
The use of carbon fiber-based composites in high-temperature environments has been hindered due to the inferior oxidation resistance of standard carbon fiber. Protective coatings comprised of refractory ceramics have served in enhancing the thermal endurance of carbon fiber significantly. Although zirconium and yttrium-based materials have been hig...
Article
The distribution of measurement noise is commonly considered as an assumed Gaussian model in power systems but this assumption is not always true in reality. This paper introduces a distributed maximum-likelihood based state estimation approach for multi-area power systems using the Student’s t- distribution measurement noise model. The t-distribut...
Article
Full-text available
Flexible capacitors are a promising power source for foldable and biological electronic devices. Although various materials and device structures have been explored, they are still limited by low energy densities and slow rate capabilities compared to their rigid counterparts. Here, asymmetric carbon nanohorns are proposed as an active material to...
Article
Full-text available
In order to advance the thin film silicon solar cell technology, it is desirable to replace the layers of doped thin film silicon or its alloys with alternative materials that can be deposited by simple physical vapor deposition (PVD) methods. Here, a dopant free a-Si:H solar cell design of Asahi U substrate | MoOx | a-Si:H | LiF | Al is investigat...
Article
Full-text available
It is shown here that silicon (Si) based solar cells can be deposited by physical vapour deposition (PVD) methods only. These cells are called the PVD-Si cells. Their processing eliminates the deposition methods involving high temperature processing steps, and / or expensive, toxic and flammable gases used for processing conventional solar cells wi...
Article
Full-text available
During the last three decades, studies of linamarin extracted from cassava have received increased attention due to the presence of high cyanogenic compounds in these extracts. The methods that are utilized to isolate linamarin are either tedious or use acidic conditions resulting in poor yields. In this study, a novel cryocooled method of extracti...
Article
Full-text available
In power systems, optimal power flow (OPF) is a complex and constrained optimization problem in which quite often multiple and conflicting objectives are required to be optimized. The traditional way of dealing with multi-objective OPF (MOOPF) is the weighted sum method which converts the multi-objective OPF into a single-objective problem and prov...
Article
Full-text available
Against the background of economic globalization, high-technology enterprises need to focus on the characteristics of corporate collaboration R&D networks and Standard-Setting. In this paper, theoretical research on corporate collaboration R&D network characteristics, technology standard-setting capability, and technology innovation performance is...
Article
Full-text available
Piezoelectric vibration energy harvesting has drawn much interest to power distributed wireless sensor nodes for Internet of Things (IoT) applications where ambient kinetic energy is available. For certain applications, the harvesting system should be small and able to generate sufficient output power. Standard rectification topologies such as the...
Article
Full-text available
A sustained release carrier system for the drug cephalexin (CEF) using functionalized graphene oxide is reported. PEGylation of GO (GO-PEG) and successful loading of CEF into PEGylated graphene oxide (GO-PEG-CEF) nanoconjugate are confirmed by Fourier Transform Infrared (FTIR) spectroscopy, Raman spectroscopy and thermogravimetric analysis. Encapsu...
Article
This paper focuses on the implementation of a hybrid Firefly Algorithm-Particle Swarm Optimization (FAPSO) scheme for optimizing the parameters of an Interval Type-2 Fractional Order Fuzzy Proportional Integral Derivative (IT2FOFPID) based Power System Stabilizer (PSS) to minimize the low frequency oscillations in a power system. Here, the IT2FOFPI...
Article
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Healing agent, epoxy encapsulated calcium carbonate microcapsules were prepared using a facile method as a self-healing composite for protective metal coatings.
Article
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Hematite nanoparticles have a broad range of outstanding applications such as in wastewater treatment, electrolytic studies, and photoelectrochemical and superparamagnetic applications. Therefore, the development of facile and novel methods to synthesize hematite nanoparticles using low-cost raw materials is an important and timely requirement. In...
Article
Full-text available
For the crystalline silicon (c-Si) heterojunction (HJ) solar cell with the conventional structure, the parasitic absorbance in the window contact layer (WCL) of p-type doped thin film silicon or its alloy (pDTF-Si/A) limits the amount of the short circuit current density (Jsc) generated. In this work, pDTFSi/A is replaced with a transition metal ox...
Article
Full-text available
Dopant free thin film solar cells with the common structure of ZnO:Al / MoOx / a–Si:H / LiF / Al are fabricated directly on flexible, transparent substrates. All the layers, except the a–Si:H layer, are deposited by simple, low temperature physical vapour deposition methods. An open circuit voltage of 0.764 V and a short circuit current density of...
Article
Semiconductor quantum dots (QDs) are promising materials for polymer‐nanocrystal hybrid solar cells (HSCs). The aim of this review article is to present a comprehensive and current overview of inorganic QDs and their applications in HSCs. Fundamental properties of QDs are first illustrated. And then recent studies that have been done to elucidate c...
Article
Full-text available
Integer linear programming (ILP) has been widely applied to solve the optimal phasor measurement unit (PMU) placement (OPP) problem for its computational efficiency. Using ILP, a placement with minimum number of Phasor Measurement Units (PMUs) and maximum measurement redundancy can be obtained while ensuring system observability. Author response: p...
Presentation
Full-text available
Vateria Copallifera is a useful tropical plant which belongs to the family of Dipterocarpaceae. It is endemic to Sri Lanka and has been classified as an endangered plant in the 2011 IUCN Red List of threatened species. It is also a promising source for novel bioactive secondary metabolites with diverse chemical structures. The aims of this study is...
Article
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In order to efficiently extract power from piezoelectric vibration energy harvesters, various active rectifiers have been proposed in the past decade, which include synchronized switch harvesting on inductor (SSHI), synchronous electric charge extraction (SECE), and so on. Although reported active rectifiers show good performance improvements compa...
Article
Predicting stock market index is very challenging as financial time series shows highly non-linear and non-stationary patterns. In this paper, an ensemble incremental learning model is presented for stock price forecasting, which is composed of two decomposition methods: discrete wavelet transform (DWT) and empirical mode decomposition (EMD), as we...
Article
Full-text available
There are a number of natural remedies against cancer. Cassava (Manihot esculenta Crantz) has been proven to be a natural remedy against cancer due to the cyanogenic compounds it contains such as linamarin. A rapid and simple liquid chromatography-mass spectroscopy (LC-MS) method was developed to identify and quantify linamarin in Cassava. The meth...
Conference Paper
Full-text available
Linamarin is a cyanogenic and hydrophilic β-linked glycoside and a secondary metabolite found within a wide range of plants most notably for Sri Lanka, linamarin is the dominant cyanogenic glycoside found in cassava (Manihot esculenta). The role of cyanogenic glycosides in plants, cassava in particular, is regarded to be twofold: serving as a defen...
Article
Symmetries in physical systems are defined in terms of conserved Noether Currents of the associated Lagrangian. In electrodynamic systems, global symmetry is defined through conservation of charges, which is reflected in gauge symmetry; however, loss of charges from a radiating system can be interpreted as localized loss of the Noether current whic...
Conference Paper
Full-text available
The irrational use of antibiotics has resulted in the development of resistant bacterial strains creating a global issue. Therefore, there is an escalating need to improve the effect of antibiotics against bacterial resistance via the drug delivery formulations. Incorporating a known antibacterial agent can enhance existing antibacterial and anti-i...
Conference Paper
Full-text available
Heparin and warfarin are widely used clinically for thrombotic diseases. However, their use is accompanied with severe side effects such as bleeding and thrombocytopenia. Therefore, novel and safe anticoagulant agents are in demand, for which compounds derived of natural sources are believed to be important. Tea, a product made up from leaf and bud...
Conference Paper
Full-text available
Iron together with folic acid is important for the treatment of anemia. A novel chitosan-alginate nanoparticulate system was developed for co-delivery of iron and folic acid as a combinatorial approach to treat anemia. Iron-folic acid loaded nanoparticles were formulated by ionic gelation method and ferrous ascorbate was loaded followed by folic ac...
Article
Full-text available
Optimizing reactive power flow in electrical network is an important aspect of system study as the reactive power supports network voltage which needs to be maintained within desirable limits for system reliability. A network consisting of only conventional thermal generators has been extensively studied for optimal active and reactive power dispat...