1,536 research outputs found

    Seroprevalence of toxocariasis in children aged 1-9 years in western Islamic Republic of Iran, 2003

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    We determined the seroprevalence of Toxocara canis infection in 544 children under 10 years randomly selected from urban and rural areas of Hamadan, An enzyme-linked immunosorbent assay was used for detection of antibodies to T. canis excretion - secretion antigens. Using a questionnaire, epidemiological factors associated with infection were examined, including age, sex, residence. Antibodies to T. canis were detected in 29 children (5.3%) and 19 children (3.5%) were categorized as borderline positive; thus together this gave a prevalence of toxocariasis of 8.8%. No significant differences were found in terms of sex, age and residence

    Antioxidant and antihemolytic activities of methanol extract of Hyssopus angustifolius

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    This study was designed to evaluate antioxidant and antihemolytic activities of Hyssopus angustifolius flower, stem and leaf methanol extracts by employing various in vitro assays. The leaf extract showed the best activity in DPPH (63.2 ± 2.3 μg mL-1) and H2O2  (55.6 ± 2.6 μg mL-1) models compared to the other extracts. However, flower extract exhibited the highest Fe2+ chelating activity (131.4 ± 4.4 μg mL-1). The extracts exhibited good antioxidant activity in linoleic acid peroxidation and reducing power assays, but were not comparable to vitamin C. The stem (23.58 ± 0.7 μg mL-1) and leaf (26.21 ± 1 μg mL-1) extracts showed highest level of antihemolytic activity than the flower extract

    Patterned and Disordered Continuous Abelian Sandpile Model

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    We study critical properties of the continuous Abelian sandpile model with anisotropies in toppling rules that produce ordered patterns on it. Also we consider the continuous directed sandpile model perturbed by a weak quenched randomness and study critical behavior of the model using perturbative conformal field theory and show the model has a new random fixed point.Comment: 11 Pages, 6 figure

    Effect of replacement of Caspian Sea gammarus meal by partial kilka fish meal on growth performance, feed conversion ratio and survival of juveniles of rainbow trout (Oncorhynchus mykiss)

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    The effects of using different of gammarus meal levels (0, 5, 10 and 20%) instead of kilk fish meal as a protein source on growth performance, feed conversion ratio and survival of rainbow trout (Oncorhynchus mykiss) fingerlings were studied over 8 weeks. Rainbow trout fingerlings (mean body weight 5.48 ± 0.32g) were reared in a completely randomized design with three replications in the same conditions. Based on the results, no significant difference was observed in the final length and weight and specific growth rate among treatments. Increase of gammarus meal in diet led to increase of feed conversion ratio and decrease of survival, but the difference was not significant among treatments. Commercial analysis showed that the cost price of feed increased with increase of gammarus meal in diet, significantly. Thus, results of our study showed that adding up to 10% of gammarus meal instead of kilka fish meal in rainbow trout fingerlings diet is suitable, considering gammarus abundance in the shores of south Caspian Sea and lack of significance in difference on growth, feed conversion ratio and survival

    Enhancing properties of iron and manganese ores as oxygen carriers for chemical looping processes by dry impregnation

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    The use of naturally occurring ores as oxygen carriers in CLC processes is attractive because of their relative abundance and low cost. Unfortunately, they typically exhibit lower reactivity and lack the mechanical robustness required, when compared to synthetically produced carriers. Impregnation is a suitable method for enhancing both the reactivity and durability of natural ores when used as oxygen carriers for CLC systems. This investigation uses impregnation to improve the chemical and mechanical properties of a Brazilian manganese ore and a Canadian iron ore. The manganese ore was impregnated with Fe2O3 and the iron ore was impregnated with Mn2O3 with the goal of forming a combined Fe/Mn oxygen carrier. The impregnated ore’s physical characteristics were assessed by SEM, BET and XRD analysis. Measurements of the attrition resistance and crushing strength were used to investigate the mechanical robustness of the oxygen carriers. The impregnated ore’s mechanical and physical properties were clearly enhanced by the impregnation method, with boosts in crushing strength of 11–26% and attrition resistance of 37–31% for the impregnated iron and manganese ores, respectively. Both the unmodified and impregnated ore’s reactivity, for the conversion of gaseous fuel (CH4 and syngas) and gaseous oxygen release (CLOU potential) were investigated using a bench-scale quartz fluidised-bed reactor. The impregnated iron ore exhibited a greater degree of syngas conversion compared to the other samples examined. Iron ore based oxygen carrier’s syngas conversion increases with the number of oxidation and reduction cycles performed. The impregnated iron ore exhibited gaseous oxygen release over extended periods in an inert atmosphere and remained at a constant 0.2% O2 concentration by volume at the end of this inert period. This oxygen release would help ensure the efficient use of solid fuels. The impregnated iron ore’s reactivity for CH4 conversion was similar to the reactivity of its unmodified counterpart. The unmodified manganese ore converted CH4 to the greatest extent of all the samples tested here, while the impregnated manganese ore exhibited a decrease in reactivity with respect to syngas and CH4 conversion.EPSR

    Correlations and the Cross Section of Exclusive (e,epe,e'p) Reactions for 16^{16}O

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    The reduced cross section for exclusive (e,epe,e'p) reactions has been studied in DWIA for the example of the nucleus 16^{16}O using a spectral function containing effects of correlations. The spectral function is evaluated directly for the finite nucleus starting from a realistic nucleon-nucleon interaction within the framework of the Green's function approach. The emphasis is focused on the correlations induced by excitation modes at low energies described within a model-space of shell-model configurations including states up to the sdgsdg shell. Cross sections for the pp-wave quasi-hole transitions at low missing energies are presented and compared with the most recent experimental data. In the case of the so-called perpendicular kinematics the reduced cross section derived in DWIA shows an enhancement at high missing momenta as compared to the PWIA result. Furthermore the cross sections for the ss- and dd-wave quasi-hole transitions are presented and compared to available data at low missing momenta. Also in these cases, which cannot be described in a model without correlations, a good agreement with the experiment is obtained.Comment: 12 pages, LaTeX, 4 figures include

    Abelian Sandpile Model on the Honeycomb Lattice

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    We check the universality properties of the two-dimensional Abelian sandpile model by computing some of its properties on the honeycomb lattice. Exact expressions for unit height correlation functions in presence of boundaries and for different boundary conditions are derived. Also, we study the statistics of the boundaries of avalanche waves by using the theory of SLE and suggest that these curves are conformally invariant and described by SLE2.Comment: 24 pages, 5 figure

    Role of surface oxygen-to-metal ratio on the wettability of rare-earth oxides

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    Hydrophobic surfaces that are robust can have widespread applications in drop-wise condensation, anti-corrosion, and anti-icing. Recently, it was shown that the class of ceramics comprising the lanthanide series rare-earth oxides (REOs) is intrinsically hydrophobic. The unique electronic structure of the rare-earth metal atom inhibits hydrogen bonding with interfacial water molecules resulting in a hydrophobic hydration structure where the surface oxygen atoms are the only hydrogen bonding sites. Hence, the presence of excess surface oxygen can lead to increased hydrogen bonding and thereby reduce hydrophobicity of REOs. Herein, we demonstrate how surface stoichiometry and surface relaxations can impact wetting properties of REOs. Using X-ray Photoelectron Spectroscopy and wetting measurements, we show that freshly sputtered ceria is hydrophilic due to excess surface oxygen (shown to have an O/Ce ratio of ∼3 and a water contact angle of ∼15°), which when relaxed in a clean, ultra-high vacuum environment isolated from airborne contaminants reaches close to stoichiometric O/Ce ratio (∼2.2) and becomes hydrophobic (contact angle of ∼104°). Further, we show that airborne hydrocarbon contaminants do not exclusively impact the wetting properties of REOs, and that relaxed REOs are intrinsically hydrophobic. This study provides insight into the role of surface relaxation on the wettability of REOs.National Science Foundation (U.S.) (Career Award 0952564)Center for Clean Water and Clean Energy at MIT and KFUPM (Project MIT-KFUPM-R16)Hydro Research Foundation (Graduate Award

    Generating GHZ state in 2m-qubit spin network

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    We consider a pure 2m-qubit initial state to evolve under a particular quantum me- chanical spin Hamiltonian, which can be written in terms of the adjacency matrix of the Johnson network J(2m;m). Then, by using some techniques such as spectral dis- tribution and stratification associated with the graphs, employed in [1, 2], a maximally entangled GHZ state is generated between the antipodes of the network. In fact, an explicit formula is given for the suitable coupling strengths of the hamiltonian, so that a maximally entangled state can be generated between antipodes of the network. By using some known multipartite entanglement measures, the amount of the entanglement of the final evolved state is calculated, and finally two examples of four qubit and six qubit states are considered in details.Comment: 22 page
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