Predicting the remaining life of timber bridges

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

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

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

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

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

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

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

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

Phenotypic and genotypic distribution of ESBL, AmpC β-lactamase and carbapenemase-producing Enterobacteriaceae in community-acquired and hospital-acquired urinary tract infections in Sri Lanka

Objectives: Although Sri Lanka belongs to a region with a high prevalence of extended-spectrum β-lactamase (ESBL), AmpC β-lactamase and carbapenemase-producing Enterobacteriaceae, data regarding antimicrobial resistance (AMR) is limited. We studied the prevalence and diversity of β-lactamases produced by Enterobacteriaceae urinary pathogens from two hospitals in the Western Province of Sri Lanka. Methods: ESBL, AmpC β-lactamase and carbapenemase production was detected by phenotypic testing followed by genotyping. Results: The species responsible for urinary tract infections (UTI) were Escherichia coli (69%), Klebsiella pneumoniae (16%) and Enterobacter sp (6%). The prevalence of ESBL (50%), AmpC β-lactamase (19%) and carbapenemase (11%) phenotypes was high, and greater in hospital-acquired (HA-UTI) (75%) than in community-acquired UTI (CA-UTI) (42%). Identification of CA-UTI caused by carbapenemase-producing Enterobacteriaceae (5%) is alarming. Only one ESBL gene, blaCTX- M-15, was detected. AmpC β-lactamase genes found in E. coli and K. pneumoniae were blaCMY-2, blaCMY-42 and blaDHA-1, while Enterobacter sp. carried blaACT-1. Carbapenemase genes were blaNDM-1, blaNDM-4, blaOXA-181 and blaOXA-232, while blaKPC, blaIMP and blaVIM were absent. Co-occurrence of multiple bla genes, with some isolates harbouring six different bla genes, was common. Carbapenem-resistant isolates without carbapenemase genes displayed mutations in the outer membrane porin genes, ompF of E. coli and ompK36 of K. pneumoniae. Factors associated with UTI with β-lactamase-producing Enterobacteriaceae were age ≥50 years, previous hospitalization, presence of an indwelling urinary catheter, history of diabetes mellitus or other chronic illness and recurrent urinary tract infections. Conclusion: This study adds to the currently scarce data on AMR in Sri Lanka

ESTIMATION OF LIQUID EMISSION LOADS FROM INDUSTRIES WITHIN THE KELANI RIVER BASIN

The Kelani River could be ranked as the largest recipient of industrialeffluents of the country. The pollution burden of this effluent is quite diverseranging from food manufacturing industries to heavy industrial dischargesfrom textile factories, tanneries, soap and cleaning preparationsmanufacturing plants and rubber factories. An attempt was made to estimatethe liquid emission loads released annually into the Kelani River Basin by theabove sectors.Liquid emission loads were assessed in terms of Biological Oxygen Demand(BOD) and Total Suspended Solid (TSS) content. In certain cases specialparameters such as Chemical Oxygen Demand (COD) and Chromium werealso assessed because of chemical contamination and hazardous potential. Inestimating emission loads Rapid Assessment Procedure and the Date BadeUrban Pollution Control Model were used as the guide.The results of the study indicate that the Kelani River receives 766.73 tons ofBOD and 462.04 tons of TSS annually from the above mentioned industrialsectors and 3.8 million cubic meters of annual industrial wastewater volume.In addition, the tanneries and leather finishing factories discharge untreatedeffluent, which is contaminated with chromium, a hazardous heavy metalhaving bioaccumulation potential, into the river basin. The amount ofchromium released into the river is as high as 6.36 tons while the COD loadfrom rubber manufacturing sector is 48.71 tons annually