EXAFS

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Determination of Adsorption and Speciation of Chromium Species by Saltbush (Atriplex ‎Canescens) Biomass using a Combination of Xas and Icp–Oes

Journal Title, Volume, Page: 
Microchemical Journal Volume 81, Issue 1, Pages 122–132
Year of Publication: 
2005
Authors: 
Maather F. Sawalha
Environmental Science and Engineering PhD Program, The University of Texas at El Paso, 500 West University Avenue, El Paso, TX 79968-0513, USA
Current Affiliation: 
Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine
J.L. Gardea-Torresdey
Environmental Science and Engineering PhD Program, The University of Texas at El Paso, 500 West University Avenue, El Paso, TX 79968-0513, USA
J.G. Parsons
Department of Chemistry, The University of Texas at El Paso, 500 West University Avenue, El Paso, TX 79968-0513, USA
Geoffrey Saupe
Department of Chemistry, The University of Texas at El Paso, 500 West University Avenue, El Paso, TX 79968-0513, USA
J.R. Peralta-Videa
Department of Chemistry, The University of Texas at El Paso, 500 West University Avenue, El Paso, TX 79968-0513, USA
Preferred Abstract (Original): 

Studies were performed to determine the effect of pH on chromium (Cr) binding by native, esterified, and hydrolyzed saltbush (Atriplex canescens) biomass. In addition, X-ray absorption spectroscopy studies were performed to determine the oxidation state of Cr atoms bound to the biomass. The amounts of Cr adsorbed by saltbush biomass were determined by inductively coupled plasma–optical emission spectroscopy (ICP–OES). For Cr(III), the results showed that the percentages bound by native stems, leaves, and flowers at pH 4.0 were 98%, 97%, and 91%, respectively. On the other hand, the Cr(VI) binding by the three tissues of the native and hydrolyzed saltbush biomass decreased as pH increased. At pH 2.0 the stems, leaves, and flowers of native biomass bound 31%, 49%, and 46%, of Cr(VI), respectively. The results of the XAS experiments showed that Cr(VI) was reduced in some extend to Cr(III) by saltbush biomass at both pH 2.0 and pH 5.0. The XANES analysis of the Cr(III) reaction with the saltbush biomass parts showed an octahedral arrangement of oxygen atoms around the central Cr(III) atom. The EXAFS studies of saltbush plant samples confirmed these results.

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Removal of Cadmium from Contaminated Waters Using Saltbush (Atriplex Canescens) Biomass: Identification of Cd Binding Sites

Journal Title, Volume, Page: 
International Journal of Environment and Pollution, Volume 34, Pages 28-42
Year of Publication: 
2008
Authors: 
Maather F. Sawalha
Environmental Science and Engineering PhD Program, University of Texas at El Paso, El Paso, 79968 TX, USA
Current Affiliation: 
Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine
Jose R. Peralta-Videa
Chemistry Department, University of Texas at El Paso, El Paso, 79968 TX, USA
Jason G. Parsons
Chemistry Department, University of Texas at El Paso, El Paso, 79968 TX, USA
Jorge H. Gonzalez
Chemistry Department, University of Texas at El Paso, El Paso, 79968 TX, USA
Jorge L. Gardea-Torresdey
Environmental Science and Engineering PhD Program, and Chemistry Department, University of Texas at El Paso, El Paso, 79968 TX, USA
Preferred Abstract (Original): 

The effect of pH on Cd(II) binding capacity of saltbush biomass was determined. Metal quantification performed using ICP/OES showed that Cd binding increased as pH increased from 2.0 to 5.0. The highest percentage of Cd bound ranged from 74-81%, 22-40%, and 70-80% for the native, esterified, and hydrolysed biomass. XAS studies showed that cadmium was present as Cd(II) and oxygen was the nearest neighbouring atom with bond lengths of approximately 2.3 Å and coordination numbers ranging between 4 and 5. Results indicated that carboxyl groups may be the primary ligand involved in the Cd binding by saltbush biomass.

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Diaminediphosphineruthenium(II) Interphase Catalysts for the Hydrogenation of α, β-Unsaturated Ketones

Journal Title, Volume, Page: 
Zeitschrift für anorganische und allgemeine Chemie Volume 629, Issue 1, pages 161–171, January 2003
Year of Publication: 
2003
Authors: 
Prof. Dr. Ekkehard Lindner
Tübingen, Institut für Anorganische Chemie der Universität
Samer Al-Gharabli
Tübingen, Institut für Anorganische Chemie der Universität
Ismail Warad
Tübingen, Institut für Anorganische Chemie der Universität
Current Affiliation: 
Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine
Hermann A. Mayer
Tübingen, Institut für Anorganische Chemie der Universität
Stefan Steinbrecher
Tübingen, Institut für Angewandte Physik der Universität
Michael Seiler
Stuttgart, Institut für Physikalische Chemie der Universität
Helmut Bertagnolli
Stuttgart, Institut für Physikalische Chemie der Universität
Erich Plies
Tübingen, Institut für Angewandte Physik der Universität
Preferred Abstract (Original): 
The T—silyl functionalized diamine-bis(ether-phosphine)ruthenium(II) complexes 1a(T°) — 1g(T°) (Scheme 1) were sol-gel processed in the presence of different amounts of the co-condensation agents CH3Si(OMe)3(Me—T°) and (MeO)2SiMe—(CH2)6—MeSi(OMe)2(D°—C6—D°) to produce a library of the interphase catalysts X1a — X1c, X2a — X2g, and X3a — X3g. Due to the remarkable electronic and steric effects of the co-ligands on the catalytic activity of such complexes, a series of aliphatic and aromatic diamines was selected. The new polymers were investigated by multinuclear CP/MAS solid-state NMR spectroscopy as well as by EXAFS, EDX, SEM, and BET methods. Selected interphase catalysts show high activities and selectivities in the hydrogenation of trans-4-phenyl-3-butene-2-one.
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Extended X-Ray Absorption Fine Structure Study on Bi Modified Ges Bulk Glasses

Journal Title, Volume, Page: 
Journal of Optoelectronics and Advanced Materials Vol. 3, No. 2, June 2001, p. 485 - 490
Year of Publication: 
2001
Authors: 
G. Saffarini
Department of Physics, Faculty of Sciences, An-Najah National University, Palestine
Current Affiliation: 
Department of Physics, Faculty of Sciences, An-Najah National University, Palestine
J. M. Saitera
Laboratoire d’Etude et de Caractérisation des Amorphes et des polymères, Faculté des Sciences, Université de Rouen, 76821 Mont Saint Aignan CEDEX, France
A. Zumailana
Department of Physic, Faculty of Sciences and Education, University of Aden, Republic of Yemen
Preferred Abstract (Original): 

EXAFS measurements have been performed from the Ge K edge and Bi LIII edge on GeSBi glasses with 6, 8 and 16 Bi at. %, and on crystalline Bi2S3. As expected, Ge is found to be fourfold coordinated with S atoms. It is also found that Bi is only coordinated with S with a coordination number CN = 4. This result for the CN of Bi contradicts the conclusion of Elliot and Steel. On the basis of the obtained CN of Bi, it is possible to exclude the presence of Bi2S3 microcrystalline inclusions and to assert that these glasses are homogeneous at the microscopic level.

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