405 research outputs found

    Changes in Coastal Landforms from the Poonaryn Peninsula to the Malwathu Oya (Aruvi Aru) Estuary, Northwestern Coastal Zone (NWCZ) of Sri Lanka

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    Changing coastal landforms are constantly occurring due to wind, waves, sea currents, tidal fluctuations, and human interference. This paper makes a special effort to ensure the correct usage, management and utilization of these landforms, which will benefit society through economic growth. A variety of peculiar coastal landforms have formed between the Poonaryn Peninsula (9°36'10.23"N, 80°03'16.74"E) and Malwathu Oya (Aruvi Aru) estuary (8°46'30.22"N and 79°56'12.85"E), which are approximately 120 km long coastal stretch. The Poonaryn Peninsula extends from Pallikuda Beach to Kalladi Yutha Kovil (9°35'53"N, 80°3'10"E). The peninsula stretches northwest to southeast, covering dunes with a maximum elevation of 17 meters. The selected study location is favourable for the coastal environment, and the coastal environment can be defined as the area lying at the interface between land and Mannar Bay, Palk Bay and a part of the Jaffna Lagoon. This area includes non-barrier delta estuaries with seasonal rivers and bar-built perennial delta estuaries. The zone of shallow water within which waves can move sediment and the area landward of this zone, including beaches, low coastal dunes and vegetation cover, are affected to some degree by the direct or indirect effects of waves, tides, winds and currents. The coastal environment itself may extend inland for many meters or kilometers. These processes make it possible to identify several coastal habitats, such as mangroves, salt marshes, covered and covered dunes, beaches, barrier beaches and spits. Lagoons, riverine estuaries, brackish water bodies, water holes, and marshes. When considering biodiversity, local and migratory avifauna, beach mangroves, seagrass beds, tidal creek system are very important for tourist attraction. Additionally, fishery harbours, boat landing sites, traditional fisheries (beach seines, koodo fishing), etc., and tourism were established in the northwestern coastal stretch owing to enticing coastal processes and landforms in the area for correct usage, management and utilization for enormous benefits of the fishing society, the environment and the economy. DOI: http://doi.org/10.31357/fhss/vjhss.v09i02.0

    Predicting the remaining life of timber bridges

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    This paper documents the current state of knowledge relating to the deterioration of timber bridges in Australia. The aim of this research, was to comprehend the present state of knowledge regarding maintenance of timber bridges and address any gap in knowledge. This involved: identifying key defects in timber, investigat-ing the inspection methods utilised to detect these faults and finding the preven-tive measures used to mitigate bridge deterioration. Enclosed are figures which demonstrate how simple industry practices and procedures implemented by each states’ governing authority can reduce these impacts and concludes with an em-pirical model for predicting the remaining lifespan of a bridge

    Interstitial cell network volume is reduced in the terminal bowel of ageing mice

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    Ageing is associated with impaired neuromuscular function of the terminal gastrointestinal (GI) tract, which can result in chronic constipation, faecal impaction and incontinence. Interstitial cells of cajal (ICC) play an important role in regulation of intestinal smooth muscle contraction. However, changes in ICC volume with age in the terminal GI tract (the anal canal including the anal sphincter region and rectum)have not been studied. Here, the distribution, morphology and network volume of ICC in the terminal GI tract of 3‐to 4‐month‐old and 26‐to 28‐month‐old C57BL/6mice were investigated. ICC were identified by immunofluorescence labelling of wholemount preparations with an antibody against c‐Kit. ICC network volume was measured by software‐based 3D volume rendering of confocal Z stacks. A significant reduction in ICC network volume per unit volume of muscle was measured in aged animals. No age‐associated change in ICC morphology was detected. The thickness of the circular muscle layer of the anal sphincter region and rectum increased with age, while that in the distal colon decreased. These results suggest that ageing is associated with a reduction in the network volume of ICC in the terminal GI tract, which may influence the normal function of these regions

    Fabrication of Yttrium Ferrite Nanoparticles by Solution Combustion Synthesis

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    The ternary oxide system Y-Fe-O presents fascinating magnetic properties that are sensitive to the crystalline size of particles. There is a major challenge to fabricate these materials in nano-crystalline forms due to particle conglomeration during nucleation and synthesis. In this paper we report the fabrication of nano sized crystalline yttrium ferrite by solution combustion synthesis (SCS) where yttrium and iron nitrates were used as metal precursors with glycine as a fuel. The magnetic properties of the product can be selectively controlled by adjusting the ratio of glycine to metal nitrates. Yttrium ferrite nano-powder was obtained by using three concentration of glycine (3, 6 and 10 wt.%) in the initial exothermic mixture. Increasing glycine content was found to increase the reaction temperature of the system. The structural and magnetic properties of yttrium ferrite before and after annealing at temperature of 1000 °C were investigated by X-ray diffractometry, Differential Scanning Calorimetry (DSC) and cryogenic magnetometry (PPMS, Quantum Design). X-ray diffraction showed that, a broad diffraction peak was found for all samples indicating the amorphous nature of the product. Particle size and product morphology analysis identified that, Nitrate/ glycine combustion caused considerable gas evolution, mainly carbon dioxide, N2 and H2O vapor, which caused the synthesized powders to become friable and loosely agglomerated for glycine concentration from 3 wt.% up to 10 wt.%. The study of the magnetic properties of produced materials in a metastable state was performed by measuring dependencies of Magnetization (M) on temperature, and magnetization on magnetic field strength between 5 K and 300 K. Magnetization measurements on temperature zero-fieldcooled and field-cooled show different patterns when the fraction of glycine is increased. The analysis of zero-field-cooled (ZFC), field-cooled (FC) and magnetization curves of annealed samples confirmed that nanoparticles exhibit superparamagnetic behavior. The increasing concentration of glycine leads to an increased blocking temperature

    Overview of different types of fly ash and their use as a building and construction material

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    Fly ash is produced, in massive amount, as a waste material of burning fossil fuel (coal combustion) for the thermal generation of electricity. Currently about 900 million tonnes of fly ash produced, worldwide, annually and about 30-40% of this residue is being utilized for various purposes including in cement and concrete production. Disposing the remaining percentage is costly as it should be done carefully to avoid any environmental pollution, mainly groundwater contamination. There are different types of fly ash, including Class F and Class C, generated by burning black coal and brown coal respectively. Class F and Class C are being utilized in making building materials such as concrete, lightweight aggregate, bricks etc. Also fly ash is used as a material for road construction and earth filled dam construction. This paper outlines an overview of using fly ash as a raw material in producing various building materials and methods of how fly ash is being incorporated with other materials. The major benefits and limitations of using fly ash as a building and construction materials are discussed

    Structural evolution and magnetic properties of Gd2Hf2O7 nanocrystals: Computational and experimental investigations

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    Structural evolution in functional materials is a physicochemical phenomenon, which is important from a fundamental study point of view and for its applications in magnetism, catalysis, and nuclear waste immobilization. In this study, we used x-ray diffraction and Raman spectroscopy to examine the Gd2Hf2O7 (GHO) pyrochlore, and we showed that it underwent a thermally induced crystalline phase evolution. Superconducting quantum interference device measurements were carried out on both the weakly ordered pyrochlore and the fully ordered phases. These measurements suggest a weak magnetism for both pyrochlore phases. Spin density calculations showed that the Gd3+ ion has a major contribution to the fully ordered pyrochlore magnetic behavior and its cation antisite. The origin of the Gd magnetism is due to the concomitant shift of its spin-up 4f orbital states above the Fermi energy and its spin-down states below the Fermi energy. This picture is in contrast to the familiar Stoner model used in magnetism. The ordered pyrochlore GHO is antiferromagnetic, whereas its antisite is ferromagnetic. The localization of the Gd-4f orbitals is also indicative of weak magnetism. Chemical bonding was analyzed via overlap population calculations: These analyses indicate that Hf-Gd and Gd-O covalent interactions are destabilizing, and thus, the stabilities of these bonds are due to ionic interactions. Our combined experimental and computational analyses on the technologically important pyrochlore materials provide a basic understanding of their structure, bonding properties, and magnetic behaviors

    Current distribution and abundance of slender lorises (Loris tardigradus and L. Iydekkerianus) in Sri Lanka

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    Two species of slender lorises are currently recognized in Sri Lanka. They are Sri Lanka red slenderloris (Loris tardigradusj and Grey slender loris (L. lydekkerianus i, with four currently recognizedsub-species; viz. Western red slender loris (L. t. tardigradus), Montane slender loris (L. t.nycticeboidesi, Northern grey slender loris (L. 1.nordicusi, and Highland slender loris (L. 1.grandis).The objective of this survey was to map the distribution and estimate the abundance of lorises in SriLanka. The study was initiated in 2002 and continues to date. Thus far forty-five sites across all ofthe ecological zones have been surveyed covering approximately 400 krn-. In six of these sites, loriseswere not recorded. Of the other 39 sites, 223 sightings of slender loris (L. t. tardigradus (n = 86), L.t. nycticeboides (n = 3), L. 1. nordicus (n = 122), and L. l. grandis (n = 12). Abundance estimates, 'base on sightings of animals krn', were: L. t. tardigradus (0.5-8), L. t. nycticeboides (0.03), L. I.nordicus (0.7-13). and L. 1. grandis (0.3-4) were recorded. The abundance of lorises varied indifferent habitat types with the highest abundance oflorises occurring in the dry zone monsoon forests.The least abundance of lorises was recorded in the cloud forest

    BREEDING STATUS OF THE PAINTED STORK Mycteria leucocephala IN THE KUMANA-VILLU OF THE YALA EAST NATIONAL PARK

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    Painted stork is a Near Threatened species that uses wetlands as their feedingand breeding grounds. The breeding colony of painted storks at Kumana villuis one of the oldest known colonies in the island. Mangrove vegetationlocated in the middle of the villu provides ideal conditions for nesting notonly for painted storks, but also for Black headed Ibises, Spoonbills, herons,egrets and even for the globally threatened Spot billed Pelicans.A survey was done in the month of July to assess breeding status of thePained Storks in this villu. The survey was land based where three mangrovevegetation patches (5000m2) were surveyed using a spotting scope (NikonFieldscope). First, all trees in each patches that contain painted stork nestswere identified. Then number of nests on each tree, number of adults,hatchlings and fledglings on nests were recorded.A total of 222 nests of painted storks were recorded. This comprised of 217active nests of which 74 contained hatchlings while 133 nests containedfledglings. Average number of nests per tree was 3.13 while the number ofnests per tree ranged from 1 to 10. Average hatchling size was 1.81 whileaverage fledgling size was 1.78 where 61.35% nests contained 2 hatchlingsor fledglings while 29.95% nests contained only one hatchling or fledgling.The nest height ranged from 1 to 10m with average nest height being 3.0m.According to the available literature the breeding season of painted storks isfrom December to May. However, during this survey it was discovered that98% of the nests were active as late as July indicating that there can be greatdeal of variation in the breeding strategies of painted storks. Furthermore,based on our studies we have estimated that there can be approximatelythousand breeding pairs of painted storks in Kumana villu, making this oneof the most important breeding sites for this species. Therefore this siteshould be continuously monitored in order to better understand the breedingbehavior of painted storks

    Evaluation of Acoustic Parameters for Angulimala Sutta using Voiced to Unvoiced Ration and Vowel Distribution

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    Pirith is believed as a protective doctrine preached by the Load Buddha in Pali language. The aim of this study is to analyze acoustic properties of Pirith using computer-aided methods and identify special characteristics and patterns. In this study, two methods were used to identify special characteristics of Angulimala Sutta. First method calculates voiced to unvoiced ratio using zero crossing rate and energy content associated with the acoustic signal while second method recognizes vowel distribution using first and second formant frequencies. Results of the first method indicates approximately 96% of frames are voiced while the second method suggests approximately 72% of vowels concentrate in the square region of F1,0~1500 Hz and demonstrating when chanting the Angulimala sutta most of the time the tongue height is low positioned in back levels while lips shaped unrounded. KEYWORDS: Formant frequencies, Voiced to unvoiced ratio, Zero-Crossing rate, Vowel distributio

    First direct 7^{7}Be electron capture QQ-value measurement towards high-precision BSM neutrino physics searches

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    We report the first direct measurement of the nuclear electron capture (EC) decay QQ-value of 7^{7}Be →\rightarrow 7^{7}Li via high-precision Penning trap mass spectrometry (PTMS). This was performed using the LEBIT Penning trap located at the National Superconducting Cyclotron Laboratory/Facility for Rare Isotope Beams (NSCL/FRIB) using the newly commissioned Batch-Mode Ion-Source (BMIS) to deliver the unstable 7^{7}Be+^{+} samples. With a measured value of QECQ_{EC} = 861.963(23) keV this result is also three times more precise than any previous determination of this quantity. This improved precision, and accuracy of the 7^7Be EC decay QQ-value is critical for ongoing experiments that measure the recoiling nucleus in this system as a signature to search for beyond Standard Model (BSM) neutrino physics using 7^7Be-doped superconducting sensors
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