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First-principles calculation on electronic properties of Bismuth-halide inorganic perovskites for solar cell
No full textSolar energy is a commonly used alternate source of energy and it can be utilized based on the principle of the photovoltaic effect. The photovoltaic effect converts sun energy into electrical energy using photovoltaic devices (solar cells)
Use of videography for traffic surveys in Sri Lanka
No full textTraffic Surveys are crucial for different transport studies like Origin-Destination studies, Traffic Volume estimations, Vehicle Flow characteristics Determinations, Speed and Delay Studies, Turning Movement analysis, Parking Analysis etc. Currently, Sri Lankan researchers are using mostly human-based manual surveys and semi-automated methods for Traffic Surveys. However, there is an issue in cost, effort, the value of time, and the accuracy of data gathering in the above methods. Therefore, under Accelerating Higher Education Expansion and Development (AHEAD) grant, we are researching the possibility of doing surveys using videography and Artificial Intelligence technologies for continuous and accurate data collection to reduce the burden that is currently facing
Factors affecting the perception of photogenic quality in public spaces; Insights from Arcade Independence Square, Colombo
No full textPhotography having one less dimension than Architecture, is one of the main elements of modern-day public user. With the growth of social media, the influence of media on the daily tasks of the average user has increased exponentially in the last decade. This study analysed the perception of public spaces in this new context of photography and social media, in relation to the photogenic quality of a space. The identification of reasons behind the perception of photogenic quality in public places would help both the designers and the government administration to create better public spaces. The study was executed with reference to three selected spaces of the Arcade Independence Square in Colombo considering 3 user groups ( n=94 ) selected based on their knowledge base namely; architecture, photography and a neutral group from general public adopting an online questionnaire survey. The findings identified visual elements of the space/composition as the significant reason behind the perception of the photogenic quality of a space followed by cultural influence and social media
Challenges on urban ageing in high density settlements: Relationship of built-environment attributes and lifestyle of elderly in Western province, Sri Lanka
No full textUrbanization and population aging are two key phenomena in the twenty-first century that concerns the elders living in cities, especially those in low- and middle-income countries like Sri Lanka. In such a setting, understanding the responsiveness of the built environment for active aging is crucial. However, even the few available studies are prioritized on health rather than the built environment attributes. Therefore, this study aims to assess the built environment attributes related to elders, for the first time, in developing countries like Sri Lanka. The assessment method composes of two case studies in Colombo, Sri Lanka with a questionnaire survey, an axial map, and a frequency analysis using the SPSS software. The case studies comprise of a middle-income and a low-income settlement both with high population density. The analysis results explicitly informed that, in comparison, the middle-income settlement is more adversely affected by the built environment response related to health and social relationships. This finding is further supported by the prominence in health-related issues of loneliness (ρ-value .042) and lack of freedom (ρ-value .014) in the middle-income settlement. The built environment attributes were ranked based on their significance in correlation with the Quality-of-Life measures and the individual age-related characteristics. This was further developed for an appraisal that assesses health-related aspects of built environment response for vulnerable age groups like elders. The findings and the appraisal could support the future decision-making process of the National health budget and future urban design interventions since Sri Lanka has the highest South Asian aging population
Perceived organizational citizenship behavior: a study of its antecedents
No full textOrganizational Citizenship Behavior (OCB) is a dynamic construct that defines employees' voluntary participation with a business. It is, nonetheless, a great factor that is generally disregarded. The acknowledged importance of OCB for organizational success has prompted numerous academics to examine the antecedents of such dispositions, dubbed proximal causes of OCB by employees. Thus, this study explores the determinants of OCB among employees in the private sector construction industry, using Supervisory Support, Conscientiousness, Internal Career Orientation, and Work-Family Conflict as independent variables. The study was quantitative, utilizing 150 self-administered questions. Multiple regression analysis was employed to test the hypotheses. Internal Career Orientation was shown to be beneficial to OCB, Supervisory Support and Consciousness were found to be significantly beneficial to OCB, and Work-Family Conflict was found to be significantly detrimental to OCB. The study may shed light on how to prescribe successful workplace behavior to employees, increasing organizational efficiency
Effect of bentonite and polymer drilling fluids on skin friction of bored piles
No full textSkin friction is a major component in any pile foundation’s load bearing capacity. In terms of a floating pile, almost entire bearing capacity depends on the skin friction. Skin friction may depend on the soil type and parameters while there are several methods of obtaining the skin frictional resistance of a pile depending on the soil type. Most of the high rise structures in Sri Lanka stand on bored end bearing pile foundations. Construction of bored piles widely involves usage of Bentonite as a drilling liquid and as a borehole soil stabilizer which may result in retention of a considerable amount of Bentonite and soil mix between the pile and the surrounding soil. Hence it is arguable that the used Bentonite slurry has an effect on the skin friction of the pile. Polymer liquid is not a commonly used drilling liquid in Sri Lanka but still it has been used in the current study. Main objective of this research is to investigate the effect of using Bentonite and Polymer liquids on the skin friction of pile foundations in Sri Lankan soils. From the results obtained from the direct shear tests conducted in laboratory for laterite soil and sand, it was evident that polymer liquid had no significant effect on soil strength parameters but with time due to the filter cake formation, bentonite will cause a significant change in soil strength parameter
a case study of Mihindusenpura Low - income housing scheme at Dematagoda
No full textHousing is a key human requirement. However, many in the modern world people are living in unsuitable houses. Recently, it has become a global problem and as a result many countries are paying attention to it and various housing strategies have emerged as solutions to low-income unsuitable settlements. According to Sri Lankan census, there are 68,812 families were living in temporary house with poor facilities within the Colombo city area (Sri Lanka’s Urban Regeneration Project continues unabated, 2020). To address this, issue the Sri Lankan Government has begun several housing programs and introduced housing policies during last decade. Out of those strategies vertical housing development became the main feature for unsuitable housing in Colombo city. Currently, more than 15,000 high rise housing units have been built for low-income people. Through the introduction of high rise buildings, another question arose on its suitability for human settlement. This has become one of the most popular topics among policy makers and professionals all around the world. In this study, an attempt was made investigate factors affection to the failure and success of vertical low-income housing in Sri Lanka by selecting low-income housing apartments in Colombo.
With the independence in 1948, housing policies have been applied to the housing sector in Sri Lanka. Condominium Property Act No. 12 of 1970 is the first legislation related to vertical housing developments in Sri Lanka. With the introduction of the Apartment Ownership Law No. 11 of 1973, the creation of huge scale tall buildings in Sri Lanka commenced.
This rule made an opportunity to convert a multi-storied apartment into a number of individual residential units which would then continue to be under a single ownership. The apartment ownership law was applied through the Condominium Act No. 45 of 1982 (Samaratunga & O'Hare, 2013).
However, settlements provided to the public in accordance with these policies do not possess better living environments for them as expected while creating numerous social problems. Hence, the management needs efficient and experienced professionals for relevant institution and authorities. This research recommends professionals and policy makers on what to concentrate on when proving settlements to low-income receiving people
Analysing the gap between predicted and actual operational energy consumption in buildings: a review
No full textOperational energy consumption in buildings has a crucial impact on global energy consumption. Nevertheless, significant energy savings can be achieved in buildings if properly designed, constructed, and operated. Building Energy Simulation (BES) plays a vital role in the design and optimisation of buildings. BES is used to compare the cost-effectiveness of energy-conservation measures in the design stage and assess various performance optimisation measures during the operational phase. However, there is a significant ‘performance gap’ between the predicted and the actual energy performance of buildings. This gap has reduced the trust and application of the BES. This article focused on investigating BES, reasons that lead to a performance gap between predicted and actual operational energy consumption of buildings, and the ways of minimising the gap. The article employed a comprehensive literature review as the research methodology. Findings revealed that reasons such as limited understanding of the building design, the complexity of the building design, poor commissioning, occupants’ behaviour, etc., influence the energy performance gap. After that, the strategies have been identified to minimise the energy performance gap such as proper commissioning, creating general models to observe occupants’ behaviour in buildings, and using the general models for energy simulation, ensuring better construction and quality through training and education, etc. Further, the findings of this study could be implemented by practitioners in the construction industry to effectively use energy simulation applications in designing energy-efficient and sustainable buildings
Barriers in implementing sustainable piling construction practices in Sri Lanka
No full textThe construction of pile foundation is a multifaceted activity among rest of the construction activities that are performed by heavy machines, materials, and energy sources generating substantial amount of CO2 and greenhouse gases along with many other forms of environmental pollution. Sustainable piling construction guarantees that the whole piling process meets environmental sustainability and ultimately human health and wellbeing. Many countries around the world, including United States, China, the United Arab Emirates, are in the forefront of reengineering piling construction activities. Implementation of sustainable practices in piling construction Sri Lanka is still at a low level. Succinctly, several hindrances and barriers can be identified when adopting sustainable piling construction practices. Hence, the aim of this paper is to identify the environmental impact due to the current piling construction practices in Sri Lanka and to investigate barriers in implementing sustainable piling construction practices. A questionnaire survey was conducted among thirty (30) experts in piling construction. Significant barriers were identified using the relative importance index technique in data analysis. The findings revealed that among the ten (10) barriers identified, cost overrun and poor pile design, investment risk, lack of awareness of sustainable techniques and technologies as the top three (3) barriers in implementing sustainable piling construction practices. The study clearly identified the need for improving sustainability practices that can also enhance cost-effectiveness and performance efficiency. Findings of this study will be useful in formulating strategies to overcome the barriers and improve sustainability practices in the local construction industry
Experimental study on load bearing capacity of cement stabilized unburnt clay bricks
No full textClay brick is one of the most widely used conventional materials in the masonry construction throughout the world. Despite living in cement age, bricks still have a defined space in our societies. Clay bricks are good for construction activities in dry zones because of its better thermal insulation and moisture control properties. With around 39 percent of the home’s energy use going towards maintaining a pleasant temperature, it has become increasingly important to build a home that will minimize the energy required for heating and cooling, from both a cost savings and sustainability perspective [1]. Bricks made with clay material can be the better option to neutralize the above condition since bricks offer superior thermal mass