Chemical Characteristics of Buffer Zone Sediments And Implications on Adjoining Water in Diyawanna Lake

Diyawanna Lake is one of the major fresh water body located in the middle of SriJayewardenapura Kotte. Most of surrounding area of the lake consists of marshlands. Duringthe recent past several reclamation and development activities going on around the lake. Inaddition, sediments from surface runoff are finally accumulating in the lake margin (bufferzone). However, there is no any study done on sediment quality and impacts of them onadjoining water, especially in the buffer zone of such a fresh water body. Therefore, main aimof this study is to investigate quality of the sediment accumulated in the buffer zone of thelake and also to study the possible impacts on lake water from the sediments due tobiogeochemical reactions in the zone. Thirty three water samples were collected during dryperiod and samples were analysed for pH, electrical conductivity (EC), oxidation reductionpotential (ORP), salinity, total dissolved solid (TDS), NO3-, PO43-, SO42-, Cl-, alkalinity,hardness, Na, K, Ca, Mg, Cd, Cr, Cu, Fe, Pb, Mn, Zn and Ni. In addition, black organicsediment samples were collected from selected locations and tested for pH, ORP, EC, organiccarbon, total organic matter, NO-3, PO4-3, Na, K, Ca, Mg, Cd, Cr, Cu, Fe, Pb, Mn, Zn and Ni.Average values of pH, EC, ORP, TDS, NO3-, PO43-, SO42-, Cl-, alkalinity, hardness, Na, K,Ca, Mg, Cu, Zn and Fe for the lake water are 7.4, 222 μS/cm, -37 mV, 222 mg/l, 0.11 ppm,15.00 ppm, 1.43 ppm, 20.00 ppm, 0.0002 ppm, 772 ppm, 16 ppm, 10 ppm, 36 ppm, 21 ppm,0.001 ppm, 0.009 ppm and 0.14 ppm respectively. However, element Cd, Pb, Mn and Niwere not detected. Piper classification for the lake water indicate CaSO4 type, which reflecttypical gypsum type of waters with impact of mine drainage due to mineral pyrite in soil.Also, sulfur emitted by the vehicles may react with water to form sulfuric acid. In addition,gypsum type of water may also due to accumulation of building materials such as cement.Therefore reason for the CaSO4 type of water may be due to several sources in the area. Inaddition, compared to WHO guidelines only Cr (0.58 ppm) present in the water isconsiderably high, this may be due to direct discharge of urban dust into the lake.Average values of pH (6.1), ORP (54 mV), EC (122 μS/cm), organic carbon (3.1%), totalorganic matter (18%), nitrate (0.93 ppm), phosphate (12 ppm), Na (3.5 g/kg), K (11 g/kg), Ca(73 mg/kg), Mg (84 mg/kg), Cd (40 mg/kg), Cr (391 mg/kg), Cu (134 mg/kg), Fe (44 g/kg),Pb (833 mg/kg), Mn (157 mg/kg), Ni (196 mg/kg) and Zn (33 g/kg) in the sediments areconsiderably different value than the water. Compare with Canadian Environment Qualityguidelines average values of Cd, Cr, Pb and Zn are higher in the sediments. This is mainlydue to accumulation of those elements from runoff water. In general, it can be concluded thatprevailing physical conditions of the lake water is controlling leaching of heavy metals fromsediments to water. Conversely, anthropogenic sources seem to be increase accumulation ofheavy metals in the buffer zone sediments.Keywords: Diyawanna Lake, Water quality, Sediment qualit

Discrete symmetries, invisible axion and lepton number symmetry in an economic 3-3-1 model

We show that Peccei-Quinn and lepton number symmetries can be a natural outcome in a 3-3-1 model with right-handed neutrinos after imposing a Z_11 x Z_2 symmetry. This symmetry is suitably accommodated in this model when we augmented its spectrum by including merely one singlet scalar field. We work out the breaking of the Peccei-Quinn symmetry, yielding the axion, and study the phenomenological consequences. The main result of this work is that the solution to the strong CP problem can be implemented in a natural way, implying an invisible axion phenomenologically unconstrained, free of domain wall formation and constituting a good candidate for the cold dark matter.Comment: 17 pages, Revtex

Equine infectious anemia : prevalence in working equids of livestock herds, in Minas Gerais, Brazil

Estimaram-se, no estado de Minas Gerais, a prevalência e a distribuição espacial da anemia infecciosa eqüina (AIE) em propriedades com eqüídeos de serviço. As amostras de sangue, de 6540 eqüídeos de 1940 rebanhos foram coletadas no período de setembro de 2003 a março de 2004, nos 853 municípios do estado. Utilizaram-se dois testes de laboratório em seqüência: ELISA, usando-se antígeno recombinante gp90, e imunodifusão em gel de ágar (IDGA). As prevalências foram de 5,3% [IC=4,3 a 6,3%] para rebanhos e de 3,1% [IC=2,2 a 3,9%] para animais. O estado de Minas Gerais foi considerado área endêmica para AIE. As mais altas prevalências para rebanhos e para animais foram encontradas na região Norte/Noroeste, seguida pela região Vale do Mucuri/Jequitinhonha. ___________________________________________________________________________________________________________ ABSTRACTThe prevalence and spatial distribution of equine infectious anemia (EIA) were estimated in livestock herds where equids were used as draft power and for transportation in the State of Minas Gerais, Brazil. Serum samples were collected from September/2003 to March/2004 in 853 municipalities of the state. The sample comprised 6,540 equids from 1,940 herds. Two laboratorial tests were performed in sequence: ELISA using a recombinant gp90 protein, following by the AGID. The prevalence in the herds was estimated in 5.3% [CI = 4.3 to 6.3%], and 3.1% [CI = 2.2 to 3.9%] of the animals tested were positive. Minas Gerais was considered an endemic region for EIA. The highest prevalence for herds and animals was found in North/Northwest region (strata) followed by Vale do Mucuri/Jequitinhonha region

Near Horizon Analysis of Extremal AdS5 Black Holes

We study the near horizon geometry of extremal black holes in five dimensional gauged supergravity using Sen's entropy function formalism. Special attention is paid to the large black hole limit where the near horizon solution exhibits a universal dependence on the rotation. The physical properties of the large black hole solution are shown to agree with predictions from fluid mechanical description of the dual conformal field theory.Comment: 26 pages, 1 figure; v2. clarifications and references adde

Web Usage Mining in Tourism — A Query Term Analysis and Clustering Approach

According to current research, one of the most promising applications for web usage mining (WUM) is in identifying homogenous user subgroups (Liu, 2008). This paper presents a prototypical workflow and tools for analyzing user sessions to extract business intelligence hidden in web log data. By considering a leading Swedish destination gateway, we demonstrate how query term analysis in combination with session clustering can be utilized to effectively explore the information needs of website users. The system thus overcomes many of the limitations of typical web site analysis tools that only offer general statistics and ignore the opportunities offered by unsupervised learning techniques

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02