Regression based polynomial chaos expansion for crop phenology estimation coupled with polsar imagery

Crop phenology monitoring using Synthetic Aperture Radar(SAR) data is gaining popularity within the remote sensing community due to SAR’s all weather and large coverage imaging capability. This paper introduces a polynomial chaos expansion (PCE) based regression algorithm to retrieve BBCH scale of crops, which identifies the phenology of crops in a standardized system. The impact and applicability of the proposed methodology is successfully illustrated using the TerraSAR-X dual-pol imagery that was acquired over the cultivation period of paddy-rice fields located in Turkey. To assess the applicability of the methodology, root mean square and correlation analysis were performed under different amount of training data and number of inputs

A Kitaev-type spin liquid on a quasicrystal

We develop an exactly solvable model with Kitaev-type interactions and study its phase diagram on the dual lattice of the quasicrystalline Ammann-Beenker lattice. Our construction is based on the $\Gamma$-matrix generalization of the Kitaev model and utilizes the cut-and-project correspondence between the four-dimensional simple cubic lattice and the Ammann-Beenker lattice to designate four types of bonds. We obtain a rich phase diagram with gapped (chiral and abelian) and gapless spin liquid phases via Monte Carlo simulations and variational analysis. We show that the ground state can be further tuned by the inclusion of an onsite term that selects 21 different vison configurations while maintaining the integrability of the model. Our results highlight the rich physics at the intersection of quasicrystals and quantum magnetism

A Radiotracer study of the adsorption behaviour of aqueous Ba2+ ions on nonoparticles of zero-valent iron

Cataloged from PDF version of article.Recently, iron nanoparticles are increasingly being tested as adsorbents for various types of organic and inorganic pollutants. In this study, nanoparticles of zero-valent iron (NZVI) synthesized under atmospheric conditions were employed for the removal of Ba2+ ions in a concentration range 10-3 to 10-6 M. Throughout the study, 133Ba was used as a tracer to study the effects of time, concentration, and temperature. The obtained data was analyzed using various kinetic models and adsorption isotherms. Pseudo-second-order kinetics and Dubinin-Radushkevich isotherm model provided the best correlation with the obtained data. Observed thermodynamic parameters showed that the process is exothermic and hence enthalpy-driven. © 2007 Elsevier B.V. All rights reserved

A radiotracer study of the adsorption behavior of aqueous Ba2+ ions on nanoparticles of zero-valent iron

Recently, iron nanoparticles are increasingly being tested as adsorbents for various types of organic and inorganic pollutants. In this study, nanoparticles of zero-valent iron (NZVI) synthesized under atmospheric conditions were employed for the removal of Ba2+ ions in a concentration range 10-3 to 10-6 M. Throughout the study, 133Ba was used as a tracer to study the effects of time, concentration, and temperature. The obtained data was analyzed using various kinetic models and adsorption isotherms. Pseudo-second-order kinetics and Dubinin-Radushkevich isotherm model provided the best correlation with the obtained data. Observed thermodynamic parameters showed that the process is exothermic and hence enthalpy-driven.2006 İYTE 1

Sorption of phenol and radioactive cesium onto surfactant modified insolubilized humic acid

In this study, the sorption behavior of two important contaminants, phenol and radioactive cesium (137Cs), onto surfactant modified insolubilized humic acid (SMIA) were investigated as a function of time, sorbate concentration utilizing the radiotracer method and UV-Vis spectroscopy. Phenol sorption process was well described by both Freundlich and Tempkin type isotherms, and cesium sorption was described by Freundlich and Dubinin-Radushkevich isotherms. It was found that SMIA adsorbs both cations and phenolic substances. Kinetic studies indicated that adsorption behavior of phenol obey the pseudo second order rate law. FTIR spectroscopic technique was used to understand the structural changes during modification process with surfactants. © 2010 Akadémiai Kiadó

Topological quantum many-body scars in quantum dimer models on the kagome lattice

We present a class of quantum dimer models on the kagome lattice with full translational invariance that feature a quantum many-body scar state of analytically known entanglement properties within their spectra. Using exact diagonalization on lattices of up to 60 sites, we show that nonscar states conform to the eigenstate thermalization hypothesis. Specifically, we show that energies are distributed according to the Gaussian ensemble expected of their respective symmetry sector, illustrate the existence of the scar from bipartite entanglement properties, and demonstrate revival phenomena in studies of fidelity dynamics

Adsorption behavior of radionuclides, 137Cs and 140Ba, onto solid humic acid

In this research, the adsorption behaviors of two important fission product radionuclides (137Cs and 133Ba) onto sodium form of insolubilized humic acid (INaA) were investigated as a function of time, cation concentration and temperature, utilizing radiotracer method. The resulting data was fitted well to the Freundlich and Dubinin-Radushkevich (D-R) isotherms. Thermodynamic constants such as; free energy (ΔGads), enthalpy (ΔHads), entropy (ΔSads) of adsorption were determined. Temperature change didn't effect sorption processes significantly. Best fitting kinetic models were found for a better understanding of adsorption mechanisms. It was found that Ba2+ was adsorbed five times more than Cs+ onto structurally modified humic acid and kinetic studies indicated that adsorption behaviors of both ions obey the pseudo second order rate law. The effect of pH changes on adsorption was also examined and optimum pH range was found in the range of pH 6-8. FTIR and solid state carbon nmr (13CNMR) spectroscopic techniques were used to understand the structural changes during insolubilization process. Quantitative determination of adsorption sites was carried out using potentiometric titration method and the resulting data was treated by using appropriate Gran functions. © Springer-Verlag Berlin Heidelberg 2011