984 research outputs found
Heavy metals in paddy fields in Taiwan: chemical behavior in soil and uptake by brown rice
Levels of cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn) were measured in 19 individual paddy fields in Taiwan. Total, reactive, and available metal levels were measured using Aqua Regia, 0.43 N HNO3, 0.1 M HCl, 0.05 M EDTA and 0.01 M CaCl2. Total metal levels ranged from below background levels to polluted and were highly heterogeneous across most fields. In general levels of metals in the soil decreased with an increase in distance from the water inlet which suggests that most metals originate from the irrigation water. Availability as measured by 0.01 M CaCl2 could be predicted well (Cd, Ni, Zn) by a Freundlich model similar to the one used in non-tropical soils. The fit of models for Cu and Pb was poor due to the lack of data on dissolved organic carbon (DOC). For Cr no fit was obtained at all. Uptake of Cd by rice was highly correlated to the availability as measured by CaCl2. Uptake models based on either the CaCl2 extractable Cd and Zn in soil solution, or a combination of the reactive Cd content in combination with pH and CEC proved equally suitable to predict Cd in rice. The impact of pH and, to a lesser extent, CEC urges the need to considere both properties when deriving soil quality standards (SQS). Uptake by rice by Indica species was markedly higher than that of Japonica although uptake by roots proved to be similar between both species. This suggests that differences between Japonica and Indica are more related to internal redistribution rather than differences in root uptake processes. Using the models, user friendly tools are designed allowing farmers and policy makers alike to evaluate the quality of the soil for a specific cultivar. This allows for a more accurate assessment of the suitability of the soil to be used for rice cropping compared to present soil standards based on Aqua Regia or HCl. As such the approach can be transferred easily to other countries as well based on a limited number of field tests
Characterization of soil heavy metal pools in paddy fields in Taiwan: chemical extraction and solid-solution partitioning
Ongoing industrialization has resulted in an accumulation of metals like Cd, Cu, Cr, Ni, Zn, and Pb in paddy fields across Southeast Asia. Risks of metals in soils depend on soil properties and the availability of metals in soil. At present, however, limited information is available on how to measure or predict the directly available fraction of metals in paddy soils. Here, the distribution of Cd, Cu, Cr, Ni, Zn, and Pb in 19 paddy fields among the total, reactive, and directly available pools was measured using recently developed concepts for aerated soils. Solid-solution partitioning models have been derived to predict the directly available metal pool. Such models are proven to be useful for risk assessment and to derive soil quality standards for aerated soils. Soil samples (0-25 cm) were taken from 19 paddy fields from five different communities in Taiwan in 2005 and 2006. Each field was subdivided into 60 to 108 plots resulting in a database of approximately 3,200 individual soil samples. Total (Aqua Regia (AR)), reactive (0.43 M HNO3, 0.1 M HCl, and 0.05 M EDTA), and directly available metal pools (0.01 M CaCl2) were determined. Solid-solution partitioning models were derived by multiple linear regressions using an extended Freundlich equation using the reactive metal pool, pH, and the cation exchange capacity (CEC). The influence of Zn on metal partitioning and differences between both sampling events (May/November) were evaluated. Total metals contents range from background levels to levels in excess of current soil quality standards for arable land. Between 3% (Cr) and 30% (Cd) of all samples exceed present soil quality standards based on extraction with AR. Total metal levels decreased with an increasing distance from the irrigation water inlet. The reactive metal pool relative to the total metal content is increased in the order C
Carrier dynamics and infrared-active phonons in c-axis oriented RuSrGdCuO film
The conductivity spectra of c-axis oriented thin RuSrGdCuO film
on SrTiO substrate, prepared by pulsed-laser deposition, are obtained from
the analysis of the reflectivity spectra over broad frequency range and
temperatures between 10 and 300 K. The free charge carriers are found to be
strongly overdamped with their scattering rate (1.0 eV at room temperature)
exceeding the plasma frequency (0.55 eV). Four phonon lines are identified in
the experimental spectra and assigned to the specific oxygen related in-plane
polarized vibrations based on the comparison with the results of a lattice
dynamics shell model calculations.Comment: 3 pages, 4 figure
Underlying Pairing States in Cuprate Superconductors
In this Letter, we develop a microscopic theory to describe the close
proximity between the insulating antiferromagnetic (AF) order and the d-wave
superconducting (dSC) order in cuprates. We show that the cuprate ground states
form a configuration of coherent pairing states consisting of extended singlet
Cooper pairs and triplet pairs, which can simultaneously describe AF and
dSC orders.Comment: 4 papes, 1 figur
Multi-layer Architecture For Storing Visual Data Based on WCF and Microsoft SQL Server Database
In this paper we present a novel architecture for storing visual data.
Effective storing, browsing and searching collections of images is one of the
most important challenges of computer science. The design of architecture for
storing such data requires a set of tools and frameworks such as SQL database
management systems and service-oriented frameworks. The proposed solution is
based on a multi-layer architecture, which allows to replace any component
without recompilation of other components. The approach contains five
components, i.e. Model, Base Engine, Concrete Engine, CBIR service and
Presentation. They were based on two well-known design patterns: Dependency
Injection and Inverse of Control. For experimental purposes we implemented the
SURF local interest point detector as a feature extractor and -means
clustering as indexer. The presented architecture is intended for content-based
retrieval systems simulation purposes as well as for real-world CBIR tasks.Comment: Accepted for the 14th International Conference on Artificial
Intelligence and Soft Computing, ICAISC, June 14-18, 2015, Zakopane, Polan
Variable length-based genetic representation to automatically evolve wrappers
The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-12433-4_44Proceedings 8th International Conference on Practical Applications of Agents and Multiagent SystemsThe Web has been the star service on the Internet, however the outsized information available and its decentralized nature has originated an intrinsic difficulty to locate, extract and compose information. An automatic approach is required to handle with this huge amount of data. In this paper we present a machine learning algorithm based on Genetic Algorithms which generates a set of complex wrappers, able to extract information from theWeb. The paper presents the experimental evaluation of these wrappers over a set of basic data sets.This work has been partially supported by the Spanish Ministry of Science
and Innovation under the projects Castilla-La Mancha project PEII09-0266-6640, COMPUBIODIVE
(TIN2007-65989), and by V-LeaF (TIN2008-02729-E/TIN)
The effects of the bacterial interaction with visible-light responsive titania photocatalyst on the bactericidal performance
Bactericidal activity of traditional titanium dioxide (TiO2) photocatalyst is effective only upon irradiation by ultraviolet light, which restricts the potential applications of TiO2 for use in our living environments. Recently carbon-containing TiO2 was found to be photoactive at visible-light illumination that affords the potential to overcome this problem; although, the bactericidal activity of these photocatalysts is relatively lower than conventional disinfectants. Evidenced from scanning electron microscopy and confocal Raman spectral mapping analysis, we found the interaction with bacteria was significantly enhanced in these anatase/rutile mixed-phase carbon-containing TiO2. Bacteria-killing experiments indicate that a significantly higher proportion of all tested pathogens including Staphylococcus aureus, Shigella flexneri and Acinetobacter baumannii, were eliminated by the new nanoparticle with higher bacterial interaction property. These findings suggest the created materials with high bacterial interaction ability might be a useful strategy to improve the antimicrobial activity of visible-light-activated TiO2
Looking Beyond Inflationary Cosmology
In spite of the phenomenological successes of the inflationary universe
scenario, the current realizations of inflation making use of scalar fields
lead to serious conceptual problems which are reviewed in this lecture. String
theory may provide an avenue towards addressing these problems. One particular
approach to combining string theory and cosmology is String Gas Cosmology. The
basic principles of this approach are summarized.Comment: invited talk at "Theory Canada 1" (Univ. of British Columbia,
Vancouver, Canada, June 2 - 4, 2005) (references updated
Temporal structure of stimulated-Brillouin-scattering reflectivity considering transversal-mode development
The time-resolved reflectivity of optical phase conjugation by stimulated Brillouin scattering ~SBS! is investigated both theoretically and experimentally. A three-dimensional and transient model of SBS is developed to compare the experimental and theoretical results. Noise initiation of the SBS process is included in the model to simulate the shot-to-shot variation in the reflectivity and the Stokes temporal profile.Shahraam Afshaarvahid, Axel Heuer, Ralf Menzel, and Jesper Munc
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