Browsing by Author "Gunasekara, S"

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item: Conference-Full-text
Nanomaterials for smart energy systems: from led to Supercapacitors and solar cells.
(2013-11-19) Kumarasimnghe, AR; Gunasekara, S; Priyadarshana, G
It has been forecast that there will be a severe impact on world economics and ecology in future by energy consumption/production that rely on the combustion of fossil fuels. Therefore more sustainable and more environmentally friendly alternative energy/power generation sources are currently under serious consideration. One such alternative is electrochemical energy production. Systems for electrochemical energy storage and conversion include batteries, fuel cells and electric double layer capacitors (EDLCs). Although the energy storage and the conversion mechanisms are different, there are “electrochemical similarities” of these three systems. Electric double layer capacitors, also known as supercapacitors or ultracapacitors, have tremendous potential as high energy high power sources for use in low weight hybrid systems. Commercial applications for such devices include uninterruptible power applications, telecommunication and transportation. The total energy stored in a conventional capacitor is proportional to both the number of charges stored and the potential between the plates. Essentially the former is a function of the size of the electrode while the later is determined by the breakdown of dielectric between the plates. Different voltages, hence energy stored, can be generated when different dielectric materials are used to separate the plates. Materials can be optimized to produce high energy densities for a given size of a capacitor. In contract to conventional capacitors, supercapacitors do not have a conventional dielectric. Instead, two layers of the same substrate and their electrical properties are used in order to effectively separate the charges despite vanishingly thin (on the order of nanometer) physical separation of the layers. Higher energy storage density can be achieved in supercapacitors when nanomaterials or materials with nanoporous structure are used because such materials offer enormous surface to volume ratio. Activated carbon is a material with unique properties especially in relation to its nanoporosity and can therefore be used in supercapacitors. Sri Lanka is one of the worlds’ best coconut shell based activated carbon producer. Besides, carbon nanotube (CNT, either MWCNT or SWCNT) can also be used in supercapacitors as electrode material where charge storage capacity can be increased to a much higher value. Ceylon vein graphite is a good source for the production of CNT. Further, the use of nano-TiO2 in conjunction with light absorbing material in cost effective solar cells is a well established process. The charge carrier generation process in solar cells mimics natural photosynthesis (green energy). At present such solar cells have efficiency nearly 11 %. Again Sri Lanka inherits a vast naturally occurring TiO2 deposit, the range of benefits of which is yet to be explored and harvested to produce nano-TiO2. Therefore nanomaterials in Sri Lanka has a wide spectrum of application and in this presentation, the opportunities to develop smart energy systems using Sri Lankan nanomaterials will be presented.
item: Thesis-Abstract
Place making : an examination of the use of the concept with special reference to selected examples in the urban context
Gunasekara, S
Architecture unlike other arts, has direct communication with people as the onlooker is subjected to both psychological and physical influence, in his total experience of 'inside' and 'outside 'Spaces and each one of us, as Alexander (1977) defines, has some where in his heart, the dream to make a living would, a universe, which suggests that human activities are mostly concentrated around the built environment and each one of us has an awareness about his place is relation to the physical form of the building and its relationships with the 'inside' and 'outside' environment. Presence of 'Place' - healthy environments is a necessity for the psychological as well as physical well being of people. The creation and demonstration of healthy Spaces 'inside 'and 'outside' a built environment is a necessary duty of an architect or the designer, as the writer sees, it is the successfully designed built form which has potentials in becoming healthy spaces, rather 'Places'. Thus the study concentrates on the successful way of designing the build form and the process of making its healthy - 'Place Making'. In this sense, the concept of Place, its constituents such as physical psychological and social, and its implications as to three urban theories are first highlighted. The concept of Place Making is even discussed in relation to theories and principles of Urban 'Place Making'. Such theories are then discussed in relation to Sri Lankan Urban situation in view of highlighting the healthyness or unhealthyness of Places.
item: Thesis-Abstract
Readiness of Sri Lankan medium and large scale IT organizations to manage IT professionals to enhance their productivity
Galhenage, JLCP; Gunasekara, S
Previous research has shown that, there is a direct relationship between retention of IT professionals and organization's HR practices[l], [2], [3], [4], [5]. This research aims to find the readiness of Sri Lankan software companies to incorporate best suite of HR practices for IT professionals to retain them. Research was carried out in three phases; Literature Review, a series of interviews with HR managers and an employee survey. This research reveals that, Sri Lankan IT industry is in the process of unveiling the strategic importance of incorporating HR practices to manage and retain IT professionals. HR professionals have identified that IT professionals have different set of needs compared to other professionals. As a result many IT companies today have taken steps to establish HR as a separate role. HR practices used in Sri Lankan IT organizations found to be compatible with the world best HR practices. According to HR managers they have given high importance to practice them within the organizations. On the other hand research revealed that IT professionals' career expectations were not fully met by the organizations' HR practices. These contradicting responses showed that there is a gap between how HR professionals and IT professionals perceive HR practices of an organization. It is interesting to note that, as a percentage, HR professionals who are qualified in the HR stream and up to date with world's 'latest trends are considerably low in Sri Lankan IT sector. Line managers' taking over HR functionality is fast becoming a world trend in the IT industry where as local. line managers still have not undertaken the HR functionality. This is due to lack of knowledge and emphasis in people management in training them before and after recruitment. Based on these research findings it can be concluded that the readiness of Sri Lankan. I'T organizations to incorporate best HR suite for fulfilling the IT professionals' career expectations are yet to be evolved even though the HR managers are well aware of the importance and need for a different way of managing the IT professionals.