213 research outputs found
Assessment of radar resolution requirements for soil moisture estimation from simulated satellite imagery
Radar simulations were performed at five-day intervals over a twenty-day period and used to estimate soil moisture from a generalized algorithm requiring only received power and the mean elevation of a test site near Lawrence, Kansas. The results demonstrate that the soil moisture of about 90% of the 20-m by 20-m pixel elements can be predicted with an accuracy of + or - 20% of field capacity within relatively flat agricultural portions of the test site. Radar resolutions of 93 m by 100 m with 23 looks or coarser gave the best results, largely because of the effects of signal fading. For the distribution of land cover categories, soils, and elevation in the test site, very coarse radar resolutions of 1 km by 1 km and 2.6 km by 3.1 km gave the best results for wet moisture conditions while a finer resolution of 93 m by 100 m was found to yield superior results for dry to moist soil conditions
A simulation study of scene confusion factors in sensing soil moisture from orbital radar
Simulated C-band radar imagery for a 124-km by 108-km test site in eastern Kansas is used to classify soil moisture. Simulated radar resolutions are 100 m by 100 m, 1 km by 1km, and 3 km by 3 km. Distributions of actual near-surface soil moisture are established daily for a 23-day accounting period using a water budget model. Within the 23-day period, three orbital radar overpasses are simulated roughly corresponding to generally moist, wet, and dry soil moisture conditions. The radar simulations are performed by a target/sensor interaction model dependent upon a terrain model, land-use classification, and near-surface soil moisture distribution. The accuracy of soil-moisture classification is evaluated for each single-date radar observation and also for multi-date detection of relative soil moisture change. In general, the results for single-date moisture detection show that 70% to 90% of cropland can be correctly classified to within +/- 20% of the true percent of field capacity. For a given radar resolution, the expected classification accuracy is shown to be dependent upon both the general soil moisture condition and also the geographical distribution of land-use and topographic relief. An analysis of cropland, urban, pasture/rangeland, and woodland subregions within the test site indicates that multi-temporal detection of relative soil moisture change is least sensitive to classification error resulting from scene complexity and topographic effects
Aqueous pathways for the formation of zinc oxide nanoparticles
We examine the effect of reactant concentrations, temperatures and feeding methods on the morphology of ZnO formed when reacting solutions of ZnSO 4 and NaOH. The catalytic effect of hydroxide in excess relative to the stoichiometric ratio is considered. It is shown that, having fixed other reaction conditions, the end-products, particle structures and size strongly depend on the mole ratio of the precursors. The presence of zinc salt hydroxide species was confirmed at sub-stoichiometric ratios in slightly acidic conditions. At the stoichiometric ratio both zinc hydroxide and zinc oxide are formed, while only zinc oxide forms in an excess of hydroxide. The method of feeding the reactants into the reaction vessel also has a strong influence on the end-product properties, as does the reaction temperature. By control of these parameters the specific surface area could be varied from 10 to 33 m 2 g-1, the particle shape could be varied from equiaxed, through to star-like and needle-like, and the particle size may be varied from 50 to over 300 nm. © 2011 The Royal Society of Chemistry
A case control study of acute leukemia risk factors in adults, Shiraz, Iran.
Abstract: Background: Leukemia is one of the most common cancers in Iran. Few studies
have focused on identifying the causative factors for leukemia. This implies the necessity of
this case-control study. This study was undertaken to identify possible risk factors associated
with leukemia. Materials and Methods: In a case-control study matched by age and sex. 100
leukemic patients admitted in hematology wards in Namazee Hospital affiliated to Shiraz
University of Medical Sciences were enrolled. Control group compromised 100 ..
Synthetic dye decolorization by three sources of fungal laccase
Decolorization of six synthetic dyes using three sources of fungal laccase with the origin of Aspergillus oryzae, Trametes versicolor, and Paraconiothyrium variabile was investigated. Among them, the enzyme from P. variabile was the most efficient which decolorized bromophenol blue (100%), commassie brilliant blue (91%), panseu-S (56%), Rimazol brilliant blue R (RBBR; 47%), Congo red (18.5%), and methylene blue (21.3%) after 3 h incubation in presence of hydroxybenzotriazole (HBT; 5 mM) as the laccase mediator. It was also observed that decolorization efficiency of all dyes was enhanced by increasing of HBT concentration from 0.1 mM to 5 mM. Laccase from A. oryzae was able to remove 53% of methylene blue and 26% of RBBR after 30 min incubation in absence of HBT, but the enzyme could not efficiently decolorize other dyes even in presence of 5 mM of HBT. In the case of laccase from T. versicolor, only RBBR was decolorized (93%) in absence of HBT after 3 h incubation. © 2012 Forootanfar et al.; licensee BioMed Central Ltd
On the formation of nanocrystalline active zinc oxide from zinc hydroxide carbonate
The decomposition of zinc hydroxide carbonate, Zn5(CO 3)2(OH)6 (ZHC), into the high surface area form of ZnO known as "active zinc oxide" is examined. In particular, the nucleation and evolution of the ZnO nanocrystals is of interest as the size of these particles controls the activity of the product. The decomposition process was studied using X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, transmission electron microscopy and BET surface area measurements. At about 240°C ZHC decomposes to porous ZnO in a single step. The product material has a specific surface area in the range of 47-65 m 2 g-1 and initially has a crystallite size that is of the order of 10 nm. A further increase in temperature, however, causes the particles to coarsen to over 25 nm in diameter. In principle, the coarsening phenomenon may be interrupted to control the particle size. © Springer Science+Business Media 2014
Effect of Lamotrigine on Prophylaxis of Pediatric Classic Migraine
ObjectiveThis study was conducted to evaluate the preventive effect of lamotringine on migraine aura and migraine attacks in children, afflicted with classic migraine.Material & MethodsConducted between October 2005 and April 2008 in the neurology clinic of Kashani hospital, Shahrekord, this study was a clinical trial, aimed at evaluating the prophylactic effects of Lamotringine administered to 21 children suffering from migraine with aura.ResultsOf the subjects, 52.4% of patients were female. The most common type of aura was visual (42.9%). Following use of Lamotrigine, significant reductions were seen in the frequency (from 5 ± 0.83 to 3.04 ± 1.65) and in intensity (from 6. 33 ± 1.08 to 3.66 ± 1.1) of migraine aura (P= 0.002). After 6 months of drug usage 66.6% of patients were improved.ConclusionLamotringine is effective in reducing the migraine aura and intensity of attacks in patients suffering from migraine with aura, and is hence beneficial for prophylactic therapy in children with classic migraine.
Commentary: consistency of EEG source localization and connectivity estimates
Bahar Moezzi and Mitchell R. Goldsworth
Study algicidial activity of 6 species (of) seaweed from Persian Gulf on growth (of) Cochlodinium polykrikoides
Harmful algal blooms resulting in red discoloration of coastal waters in the Persian Gulf, Iran were first observed in January 2007. The species responsible for the bloom, which was identified as Cochlodinium polykrikoides, coincided with massive aquatic organisms’ mortalities in the Persian Gulf. The effects of water soluble extract (0.2, 0.6, 0.8 and 1.6 g L-1) from 6 species of marine macroalgae; Ulva lactuca, Enthromorpha intistialis, Colpomenia sinuosa, Sargassum illicifolium, Gracilaria corticat and Hypnea valentiea , fresh thallus (2.5 and 5.0 g L-1) and macroalgal culture medium filtrate from 3species of marine macroalgae; E.intistialis, C.sinuosa, and H.valentiea on growth of Cochlodinium polkrikoides (Dinoflagellate) were investigated for 15 days in co-culture under controlled laboratory conditions. The results clearly showed that the growth of C. polkrikoides was significantly inhibited by the water-soluble extracts of seaweed at relatively all concentrations in contrast to control with any seaweeds extract (p<0.05). The growth inhibition of C. polykrikoides was significantly higher in co-culture with fresh thallus of E.intistialis, C.sinuosa and H.valentiea (p<0.05). In macroalgal culture medium filtrate the highest growth inhibition of C. polykrikoides was obtained in co-culture with E.intistialis and was significantly higher than the other macroalgal culture medium filtrate of seaweeds(p<0.05). Therefore, we could conclude that using the tested seaweeds either as an extract or in co-culture with fresh thallus could be used as an alternative to biological control of C. polykrikoides
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