1,680 research outputs found
Engineering Multi-Layered Encapsulations for Combinatorial Stem Cell Biology
No full textElectrospray techniques have become established in the life sciences for uses
from cell encapsulation (Chang, 1964) to directed cell placement in more recent
times (Jayasinghe et al., 2006a). During electrostatic encapsulation a conducting
fluid in a needle connected to a high voltage power supply is charged and then
drawn towards a grounded electrode by an electric field resulting in spraying.
Cells and other materials can be encapsulated by suspending them in an alginate
solution and electrospraying directly into a solution containing of a crosslinking
agent, most commonly calcium chloride. This technique can be used to directly
process and encapsulate many different types of materials (Jayasinghe and
Townsend-Nicholson, 2006, Jayasinghe, 2007, Patel et al., 2008). This research
adapts this technology further and progresses it by creating structures with
multiple layers over an extended period with fluorescent markers contained
within the layers, which are created through chemical adsorption. This allows
the encoding information for the use in combinatorial stem cell biology where
instead of individual experiments a large number of permutations are explored
simultaneously. The research covers various parameters governing the
encapsulation and layering processes as well as the biological functionality and
integration as a tool for combinatorial stem cell cultures. The novel
encapsulation and encoding technique presented here has a number of
advantages over the currently available technology and has been filed as patent
PCT/EP2010/006459
Santhanadeepaya: Heritage catholic churches of the Kalpitiya peninsula
No full textThe book is a historical and architectural survey of the Catholic churches of the Kalpitiya peninsula which is located in the North-Western province of Sri Lanka. While analysing in detail the historical evolution of art and architecture of the centre of devotion of the peninsula; the St Anne’s Shrine, Talawila, it also traces the diversity of design in other churches of the peninsula. The book also narrates the often turbulent history of the unfolding and institutional growth of Catholicism in the Kalpitiya peninsula
Recent advances in the synthesis of naturally occurring tetronic acids
No full textDuring the last decades the interest towards natural products containing the tetronic acid moiety augmented significantly, due to their challenging structures and to the wide range of biological activities they display. This increasing enthusiasm has led to noteworthy advances in the development of innovative methodologies for the construction of the butenolide nucleus. This review provides an overview of the progress in the synthesis of tetronic acid as a structural key motif of natural compounds, covering the last 15 years. Herein, the most representative synthetic pathways towards structurally diverse natural tetronic acids are grouped according to the strategy followed. The first part describes the functionalization of a preformed tetronic acid core by intermolecular reactions (cross-coupling reactions, nucleophilic substitution, multicomponent reactions) whereas the second part deals with intramolecular approaches (Dieckmann, cycloaddition or ring expansion reactions) to construct the heterocyclic core. This rational subcategorization allowed us to make some considerations about the best approaches for the synthesis of specific substrates, including modern intriguing methodologies such as microwave irradiation, solid phase anchoring, bio-transformations and continuous flow processes
Energy poverty in Sri Lanka
No full textUnderstanding energy poverty is fundamental to any efforts to alleviate it. This paper, using the latest (2016) Sri Lankan Household Income and Expenditure survey data, examines the incidence, intensity, inequality, and determinants of energy poverty in Sri Lanka, by constructing the Multidimensional Energy Poverty Index (MEPI). The MEPI is calculated using a set of seven key indicators representing multiple dimensions of energy and assigning weights by using the Principal Component Analysis (PCA). Sri Lankan households, on average, are experiencing a moderate level of energy poverty (with MEPI of 0.431) where the lack of access to modern cooking fuel is the largest contributor to energy poverty. Results of this study revealed notable differences in energy poverty by gender, age, ethnicity, and income group of the head of the household and by sub-national location of the household. Significant differences in inequality in energy poverty were also observed by sub-national location and income. While energy-poor households are not necessarily always income-poor, income and other socio-demographic and geographical factors are strongly associated with energy poverty in Sri Lanka. The findings of this study raise alarms for the possible adverse implications on health and education attainment of the energy-poor. Overall, the results provide valuable policy insights into one of the most neglected dimensions of the post-war development policy agenda in Sri Lanka, in particular, and other developing countries, in general.Full Tex
Flow behaviour of dielectric liquids in an electric field
No full textA family of 10 silicone oils with electrical conductivity similar to 10(-13) S m(-1) (a regime hitherto systematically unexplored) and viscosities ranging from 1 to 2000mPas have been Subjected to an electrical field of up to 1.5kV mm(-1) during flow from a needle. The flow behaviour of these liquids is investigated experimentally in the flow rate regime 10(-8)-10(-12) m(3) s(-1) and we analyse the results using the Ohnesorge number. Due to the low electrical conductivity and high electrical relaxation time of the silicone oils, only unsteady transient jets were found. The onset of this type of jetting has been defined using current measurements and, in contrast to conducting liquids, the non-dimensional jet diameter increases with increase in Ohnesorge number. The time elapsed between the start and finish of jetting increases with increasing Ohnesorge number
Sensitivity Analysis of Simulating Rainfall Over Sri Lanka Associated with the Cyclone Amphan Using WRF
No full textThis study is to identify the best set of physics options in simulating the daily rainfall under the influence of the cyclone "Amphan" using Weather Research and Forecasting (WRF). Twelve different combinations of physics options are experimented. Pattern correlation between the simulated and satellite measured rainfall obtained using Global Precipitation Measurement (GPM) is calculated for each experiment as a measure of simulation accuracy. In general the intensity of the simulated rainfall comparatively lower but on the other hand, the area and the pattern is accurately simulated by the identified set of physics options. The best set of physics options were identified by calculating the average pattern correlation of the simulations carried out over six days. We conclude that the use of such physics option combination with WRF has the potential in forecasting the rainfall in Sri Lanka under the influence of a cyclone.T. D. Gamage. D.U.J. Sonnadara. S. Jayasinghe. S. Basnayake, Sensitivity Analysis of Simulating Rainfall Over Sri Lanka Associated with the Cyclone Amphan Using WRF, J. Innovation Sciences and Sustainable Technologies, 2(1)(2022),33-39. DOI: https://doie.org/10.0608/JISST.2022675509, E-mails: [email protected], [email protected], [email protected], senaka [email protected]
A new approach to analyse conditional demand: An application to Australian energy consumption
No full textLaitinen et al. (1983) proposed an extension to the Working's (1943) Model which allows the marginal share to be a linear function of the corresponding budget share. In this paper, we derive the conditional (within a group of goods) version of Laitinen's Generalized Working's Model which is an important and useful generalization of the popular Working's Model with respect to the conditional case. We then use the new model to analyse the Australian energy consumption patterns conditionally for electricity, gas, petrol, and diesel using the most recent ABS Household Expenditure Survey 2015–2016 data. We found some interesting energy consumption patterns in Australia at (a) states/territories (b) remoteness of location and (c) income group levels. The results indicate that energy, as a group, is a necessity for all Australian households irrespective of their income and where they live. Within specified energy group, electricity is a necessity and petrol and diesel are luxuries for households across Australia and households of all income groups. Gas switches between being a necessity or a luxury based on the state/territory and level of remoteness. This is an appealing result that illustrates the valuable property of the Generalized Working's Model whereby a good can switch from a luxury to a necessity and vice versa, something that is ruled out in the original Working's Model.No Full Tex
sj-docx-1-cjk-10.1177_20543581231199013 – Supplemental material for Prevalence of Chronic Kidney Disease of Uncertain Etiology Within Selected Farming Communities in Rural Sri Lanka
No full textSupplemental material, sj-docx-1-cjk-10.1177_20543581231199013 for Prevalence of Chronic Kidney Disease of Uncertain Etiology Within Selected Farming Communities in Rural Sri Lanka by E. M. D. V. Ekanayake, P. Mangala C. S. De Silva, T. D. K. S. C. Gunasekara, W. A. K. G. Thakshila, S. D. Gunarathna, R. A. I. Pinipa, Sudheera Jayasinghe, E. P. S. Chandana, E. S. Wijewickrama and Nishad Jayasundara in Canadian Journal of Kidney Health and Disease</p
Analyzing and modelling web server based systems
No full textServer based systems are widely used in modern computer systems. Understanding the
performance of web server based systems, under different conditions is important. This
requires a step by step approach that includes modelling, designing, implementing,
performance testing and analyzing of results. In this research, we aim at characterizing the
web s erver s ystems under d ifferent c onfigurations. We p resent a s ummary o f p revalent server
architectures, provide a systematic approach for performance testing, and present a novel
open source Python library f or latency analysis. We experiment on existing server
architectures, and propose eight new server architectures. Our analysis shows that under
different conditions the new architectures outperform the existing architectures. Moreover
we do an extensive tail latency analysis of Java microservices
Damage detection in cable structures using vibration characteristics
No full textCable structures find many applications such as in power transmission, in anchors and especially in bridges. They serve as major load bearing elements in suspension bridges, which are capable of spanning long distances. All bridges, including suspension bridges, are designed to have long service lives. However, during this long life, they become vulnerable to damage due to changes in loadings, deterioration with age and random action such as impacts. The main cables are more vulnerable to corrosion and fatigue, compared to the other bridge components, and consequently reduces the serviceability and ultimate capacity of the bridge. Detecting and locating such damage at the earliest stage is challenging in the current structural health monitoring (SHM) systems of long span suspension bridges. Damage or deterioration of a structure alters its stiffness, mass and damping properties which in turn modify its vibration characteristics. This phenomenon can therefore be used to detect damage in a structure. The modal flexibility, which depends on the vibration characteristics of a structure, has been identified as a successful damage indicator in beam and plate elements, trusses and simple structures in reinforced concrete and steel. Successful application of the modal flexibility phenomenon to detect and locate the damage in suspension bridge main cables has received limited attention in recent research work. This paper, therefore examines the potential of the modal flexibility based Damage Index (DI) for detecting and locating damage in the main cable of a suspension bridge under four different damage scenarios. Towards this end, a numerical model of a suspension bridge cable was developed to extract the modal parameters at both damaged and undamaged states. Damage scenarios considered in this study with varied location and severity were simulated by changing stiffness at particular locations of the cable model. Results confirm that the DI has the potential to successfully detect and locate damage in suspension bridge main cables. This simple method can therefore enable bridge engineers and managers to detect and locate damage in suspension bridges at an early stage, minimize expensive retrofitting and prevent bridge collapse
- …
