ERU - 2006

Permanent URI for this collectionhttp://192.248.9.226/handle/123/14683

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item: Conference-Abstract
Analysis of bridge decks for thermal loading for the Sri Lankan industry
(2006) Weerasekera, IRA; Premawardena, VAS; Prasanna, KPN; Samarasinghe, CM
Concrete bridge structures, which are exposed to the sun are subjected to complex thermal stresses, which may vary continuously with time. The magnitude of these stresses depends mainly upon the temperature variations that occur within the cross section of the bridge deck. The nonlinear temperature variation created over the cross section of a simply supported bridge produces longitudinal self-equilibrating stresses (eigen stresses). These can be determined by restraining the simply supported beam and then releasing the restrained structure by reversing and applying the stress resultants. Using the Principle of superposition gives the desired stresses. The resulting internal forces are unaffected but there is a re-distribution of stresses in different components of a cross-section under thermal loading. In a continuous bridge, additional continuity stresses also develop. In this situation internal forces as well as external reactions change. Overall results can be obtained using superposition of self-equilibrating stresses and continuity stresses. The procedure described can be used for any practical situation as long as there is symmetry of the cross section about a vertical axis. A section containing several layers made out of different materials can also be handled in a similar way. In the situation of a complex bridge deck consisting of a grid structure the above results can be combined with a normal grillage analysis to enhance the comprehensive nature of the approach.
item:
Application of ergonomic principles in designing of human powered vehicle - the "pedal car"
(2006) Shereefdeen, Z; Fernando, MARV
Transportation is one of the key issues currently we face in Sri Lanka. Situation has become more complex with soaring fuel price. Further, petroleum fuel powered vehicles cause enormous environmental problems particularly in urban areas. A recent research has revealed that over 60% of all vehicles plying Sri Lankan roads are within the borders of the Colombo Metropolitan Region (CMR). Approximately 75% of the pollutants released to the air originate from the transport sector. On the other hand, being a poor nation having a per capita income of less than U$ 1200per annum, automobile is a luxury for the average person. Therefore use of Human Powered Vehicles (HPV) for day to day transportation becomes worth investigation and promotion.
item: Conference-Abstract
Application of total productive maintenance: a comparative study
(2006) Perera, HSC; Musadik, MBM
It is understood that the manufacturing organizations in Sri Lanka do not perform effectively in terms of resource utilization in order to compete with the international competition. There are several management shortcomings contributing to this ineffectiveness. The maintenance management is one of the negligence found in industries.
item: Conference-Extended-Abstract
Assessment of controls of information system function in organizations of Sri-Lanka
(2006) Keerthiwansa, P; Prasanna, R
IS function includes all the activities related to the information system function in the organization. In other words, it includes the planning, organizing, coordinating, controlling of information system activities and resources. Information resources include the software, hardware, data, and the users of the information system.
item: Conference-Abstract
Assessment of wave climate off the southern coast of Sri Lanka
(2006) Gunaratna, PP
Wave climate off the southern coast of Sri Lanka is characterized by the long period swell waves with nearly southerly direction of approach throughout the year and the sea waves mainly influenced by the south west monsoonal winds. Towards the southeastern part of the coastline, the influence of north eastern monsoonal waves is also seen. A proper assessment of nearshore wave climate is essential in the economical design of coastal and harbour structures and in implementing preventive measures against coastal erosion.
item: Conference-Abstract
Comparison of the embedded energy in two distinct walltile manufacturing processes in Sri Lanka
(2006) Divakara, S; Witharana, S; Attalage, RA
The ceramic industry is a highly energy intensive industry in Sri Lanka. In meeting its daily rated out put of nearly 34,000m2 which is growing at a steady rate, the ceramic factories consume a sizable chunk from the total industrial energy, both thermal and electrical, in this country. Their energy bills account for one third of the total production cost. In comparison to other ceramic manufacturing countries such as India, Indonesia, Malaysia and Italy, out cost of energy is excessively high. The unfortunate consequence is that the Sri Lankan ceramic products find it very difficult to compete in price, both in local and foreign markets.
item: Conference-Extended-Abstract
A comprehensive study of serviceability behaviour of slabs on grade
(2006) Weeraseka, IRA; Rowel, WDNP; Dassanayake, CI; Ratnayake, KC; Wickramaratne, PVL
A slab on grade is simply a slab constructed on earth or ground. Often these types of slabs are encountered in the industrial practice. There are several types of slabs on grade commonly used such as pavement slabs found in footpaths, walk ways, airport runways, highways, basement floors and bottom slab of swimming pools. The observed behaviour of these slabs is such that most of them are cracked due to serviceability problems or construction defects. This study is aimed at investigating the time dependent behaviour both at short term and long term conditions due to creep, shrinkage of concrete and relaxation of steel.
item: Conference-Abstract
Computer aided hazard analysis for mixing operation: case study of an instant string hopper mixture
(2006) Wimalasiri, KYD; Gunasekera, MY
Rapid industrialization and the severe industrial accidents occurred during the past decades have increased the public awareness on the negative impacts of present technologies used and the hazards posed by potential accidents in process industries. Developing countries in particular with high population densities and industrial zones where many industries are situated in close proximity and surrounded by densely populated neighbourhoods have a high affinity to cause severe consequences resulting from accidents. So it is of utmost importance to make efforts towards strengthening safeguards and managing risk to protect human beings, property and environment by increasing reliability of hazardous systems. This need has directed the technical community towards the development of hazard analysis and forecasting techniques.
item: Conference-Extended-Abstract
Cracks in masonry walls due to thermal movements of overlying slab
(2006) Dilrukshi, KGS; Dias, WPS
Concrete slabs exposed to direct sunlight experiences temperature related horizontal movements. In addition, temperatures on the top surface will be higher than those on the underside of the slab, causing an upward movement of the slab during heating. In a typical building, masonry and concrete structural elements restrain each other at their respective interfaces. Therefore, significant movements may be generated on the masonry walls, due to movement on roof slab. These movements can result in overstressing and cracking in masonry.
item: Conference-Abstract
Critical analysis of banki turbine
(2006) Fernando, MARV
'Banki turbine', named after its inventor professor Banki, is different from other types in that the flow through the turbine is across it. Thus some literature prefers to call it 'crossflow turbine', while some others try to name it after 'Osberger' who too seems to have developed the same concept independently, though well after Prof Banki who holds the patent for this invention.
item: Conference-Abstract
Critical success factors for mobile applications in finance sector, Sri Lanka
(2006) Basnayake, BAC; Prasanna, R
Mobile telecommunications industry worldwide has expanded and surpassed the fixed line operators. This technology evolved in the developed countries in the last decade and has been growing at a rapid pace. Due to number of reasons this technology has become an integral part of the business world and there is no choice for business organizations. In order to be competitive in the business world, organizations have to seriously consider them and adopt such technology whenever appropriate and applicable. Although Developed countries in Europe and United States have adopted mobile commerce technology, Asian countries such as Philippines and Korea are ahead.
item: Conference-Extended-Abstract
Design and construction of a machine to desalinate sea sand and to prepare it as fine aggregate for the construction industry
(2006) Allis, RLKG; Kahandagamage, GA; Lokuwithana, NPH; Punchihewa, HKG
Design and construction of a machine to desalinate and sieve sea sand is discussed. Initially, a full scale machine was designed according to the requirement. Then, the device was modelled using Pro/Engineer to depict the features and the operation of the desalination device. Finally, a miniature physical model of the proposed design was constructed to demonstrate the desalination and the sieving process.
item: Conference-Abstract
Design and development of a machine for selective plucking of tea or similar items
(2006) Krishantha, RPP; Fernando, MARV
First stage of Tea manufacture is plucking. This may be done in two ways, "Pluck and select" OR "Select and pluck - called selective plucking". First method can use simple machines, such as grass trimmers even, and impurities such as stork, matured leaves etc are removed later. This method is suitable only for lower grades of tea and also causes damage to plant and reduces growth and yield. While first method is used in certain countries such a Kenya, Japan etc., Sri Lanka being the HIGHEST quality tea manufacturer in the world, invariably use "Selective plucking" due to its many advantages. However this at present is a completely manual process and is responsible for a substantial portion of the cost of tea manufacture. Problem is further aggravated by the pluckers leaving this job due to strenuous nature and the low social status attached to it. Plantation sector thus is now finding it very difficult to retain pluckers, particularly with younger generation, and payment rates are also continuously increasing.
item: Conference-Abstract
Design of a human powered vehicle for urban environments - frame and body
(2006) Molligoda, MLCY; Fernando, MARV
The future of "green transport" is of great concern to rational planners and politicians who want to find solutions to the many environmental problems caused by the extreme popularity of the automobiles. Therefore, a research group met, studied and discussed the state of the art of human powered vehicles (HPVs).
item: Conference-Full-text
Design of a weft gripper system for required weft tension on rapier loom
(2006) Gopura, RARC; Gunasekara, JMP; Fernando, EASK
In an existing rapier loom, when the rapier comes out from the shed, the tension of the weft yam changes before the reed reaches the fabric fell. Also in case of elastic yam, a certain length of the yam may retract due to the elastic nature of the yam. With the existing systems of rapier looms, weft yam tension cannot be controlled until the weft is interlaced into the fabric. Because of the above reasons the quality, selvage and appearance of the fabric could be impaired.
item: Conference-Extended-Abstract
Design of in-vessel continuous composting process for handling sugar industrial waste
(2006) Ariyaratne, H; Ishiyama, EM; De Alwis, A; Hettiarachchi, M; Gunasekera, MY
During the past decades Sri Lanka has not satisfactorily processed agricultural products which were a major burden to the national economy. Realizing the importance of value addition, the relevant processing of agricultural products have magnified significantly, resulting in a parallel generation of processed agricultural wastes. The major focus of this paper is the introduction of a high rate in-vessel composting process for handling one of the process wastes in the sugar industry.
item: Conference-Extended-Abstract
Design, fabrication and testing of a down draft stove for small scale industrial applications
(2006) Wickramasooriya, IPTS; Witharana, S; Wickramanayake, ABAT; Sugathapala, AGT
Biomass represents the largest share of primary energy supply in Sri Lanka. For household cooking as well as large industry applications, there have been a growing trend in the development of high efficiency technologies. However, the small scale industrial sector is yet to find efficient combustion solutions
item: Conference-Extended-Abstract
Development of negative skin friction on pilesinstalled through soft compressible soils in Sri Lanka
(2006) Thilakasiri, HS
Use of grounds with soft compressible layers at shallow depths for development projects requires the use of pile foundations to support the structural loads. Piles installed through soft compressible soil layers are subjected to Negative Skin Friction (NSF) as a result of consolidation of the soft compressible layers due to placing fills, lowering of the ground water table, pile driving etc. The NSF, or commonly referred to as the drag force, is generally estimated from the skin frictional resistance due to the consolidating layer and layers above it. However, it is shown by the researchers [Bjerrum et al. (1969) and Endo et al. (1969)] that the NSF is not developed up to the bottom of the consolidating layer but only upto a point, referred as the neutral point, above the bottom of the consolidating layer. Moreover, the results of full scale field tests conducted by researchers clearly indicates that the development ofNSF is not due to the total stress but due to the effective stress acting on the pile shaft. Moreover, it is experimentally shown that the development of the ultimate NSF requires very small relative displacement between the pile and the soil. Furthermore, it is experimentally shown that the action of short-term live loads reduces the developed NSF. Therefore, the NSF and short-term live loads are not simultaneously acting on the pile.
item: Conference-Abstract
The development of rubber-thermoplastic blends from ground tyre rubber and waste polypropylene
(2006) Egodage, SM; Harper, JF; Walpalage, S
Rubber-thermoplastic blends are regarded as economical alternatives to the synthesis of new polymers with moderate characteristics and the market for such materials has grown dramatically because of the ability to recycle and process them in conventional thermoplastic machinery. Polymer blending entails the combination of the attractive features of several materials to improve the deficient characteristics of anyone of them, with a reduction in the price of the end product. Blending of polymer waste further reduces the price whilst helping to solve the waste disposal problem that industry currently faces. Rubber rich blends produce a soft thermoplastic elastomer while plastic rich blends produce a rubber toughened thermoplastic. However, literature reveals that the additions of rubber to a thermoplastic matrix result in a significant overall deterioration in mechanical properties.
item: Conference-Extended-Abstract
Evaluation of electro kinetic properties of Sri Lankan peaty clays
(2006) Kulathilaka, A
Finding economical and speedy methods for the improvement of extremely soft peaty clays is a major challenge ahead of the Sri Lankan geotechnical engineers involved in new infrastructure development projects. Peaty clays are with very high water contents and found in low lying areas in several parts of the country. Major Geotechnical problems are associated with constructions done on peaty clays due to very high primary and secondary consolidation settlements and very low shear strengths. Extremely soft consistency of soils encountered in some sites makes it impossible to place any fill without the use of reinforcements and separation layers. Even then the construction will have to be done in several stages to prevent shear failures. In this context the possibility of consolidating the extremely soft peaty clays by electro osmosis - without application of a physical load was studied.

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