scholarly journals Detailed Characterization of a Nanosecond-Lived Excited State: X-ray and Theoretical Investigation of the Quintet State in Photoexcited [Fe(terpy)2]2+

2015 ◽  
Vol 119 (11) ◽  
pp. 5888-5902 ◽  
Author(s):  
György Vankó ◽  
Amélie Bordage ◽  
Mátyás Pápai ◽  
Kristoffer Haldrup ◽  
Pieter Glatzel ◽  
...  
Keyword(s):  
Excited State ◽  
Theoretical Investigation ◽  
Detailed Characterization ◽  
X Ray ◽  
Quintet State

scholarly journals A detailed characterization of congenital defects and mortality following moderate X-ray doses during neurulation

2017 ◽  
Vol 110 (6) ◽  
pp. 467-482 ◽  
Author(s):  
Kai Craenen ◽  
Mieke Verslegers ◽  
Jasmine Buset ◽  
Sarah Baatout ◽  
Lieve Moons ◽  
...  
Keyword(s):  
Congenital Defects ◽  
Detailed Characterization ◽  
X Ray

Preparation of Magnetically Modified Zeolites and the Application of Metal Ions Adsorption

2011 ◽  
Vol 299-300 ◽  
pp. 764-769
Author(s):  
Ming Liang Yuan ◽  
Liang Yu ◽  
Jia Hua Tao ◽  
Cong Song
Keyword(s):  
Metal Ions ◽  
Industrial Effluents ◽  
Nitrogen Adsorption ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
Detailed Characterization ◽  
X Ray ◽  
Magnetic Process ◽  
Coprecipitation Process

Natural zeolites combined with the magnetic iron oxides are prepared by a chemical coprecipitation process. A detailed characterization of our magnetically modified zeolite (MMZ) is given, including powder X-ray diffraction (XRD), nitrogen adsorption and vibrating sample magnetometer (VSM). The results reveal that in comparison with Na-zeolite, the structure of MMZ has no obvious change but its surface area increases from 25.13 m2g-1to 100.90 m2g-1. The adsorption properties of MMZ to Pb2+and Cu2+were studied. The results show that the maximum loading capacities for Pb2+and Cu2+in the initial concentration range are 123.74 and 14.633 mg g-1, respectively. The MMZ can be used as an adsorbent for removal of heavy metal ions from industrial effluents or municipal waters, and the saturated adsorbent is separated from the medium by a simple magnetic process.

Solvothermal Synthesis and Luminescence Properties of Gd2O2S:RE3+ (RE3+=Eu3+/Tb3+) Hollow Sphere

2019 ◽  
Vol 807 ◽  
pp. 1-10 ◽  
Author(s):  
Guang Xi Xu ◽  
Xiao Tong Sang ◽  
Jing Bao Lian ◽  
Nian Chu Wu ◽  
Xue Zhang
Keyword(s):  
Solvothermal Synthesis ◽  
Solvothermal Method ◽  
Raw Materials ◽  
Hollow Spheres ◽  
Hollow Structure ◽  
Molar Ratio ◽  
Detailed Characterization ◽  
X Ray ◽  
Electronic Microscope

Eu3+ and Tb3+ ions singly activated Gd2O2S hollow spheres have been successfully synthesized via solvothermal method by using Gd (NO3)3, Eu (NO3)3, Tb (NO3)3 and thiourea as raw materials. Detailed characterization of the as-prepared samples were obtained by X-ray diffractometry (XRD), field emission scanning electron microscopy (FE-SEM), transmission electronic microscope (TEM) and photoluminescence (PL) spectroscopy. The results demonstrate that at 220 oC for 24 h, the molar ratio of thiourea/Gd3+ has no significant impact on the phase composition of Gd2O2S products. With the reaction time increased from 6 h to 24 h, the morphology of Gd2O2S samples changed from ellipsoidal to near-spheroidal structure, but still remained hollow structure. PL results show that the strongest emission peaks for Gd2O2S:Eu3+ and Gd2O2S:Tb3+ samples were centered at 625 nm and 545 nm, corresponding to the 5D0→7F2 transition of Eu3+ ions and 5D4→7F5 transition of Tb3+ ions, respectively. The quenching concentrations for Eu3+ and Tb3+ ions were 12% and 6%, which can be attributed to the exchange interaction for Eu3+ and Tb3+ ions, respectively.

scholarly journals SPECTROMETRIC INVESTIGATION OF PIGMENTS AND SUBSTRATA IN WOOD PAINTINGS

2014 ◽  
Vol 27 ◽  
pp. 1460134
Author(s):  
CATALINA CHIOJDEANU ◽  
ANGELA VASILESCU ◽  
MIHAELA MANEA ◽  
FLORIN CONSTANTIN ◽  
JAMES SALIBA
Keyword(s):  
Blue Pigment ◽  
Detailed Characterization ◽  
X Ray ◽  
Combined Use ◽  
Ft Raman Spectroscopy ◽  
Ft Ir ◽  
Formed Part ◽  
Identification Techniques ◽  
Ft Raman

A polychrome and gilded wooden artifact was found, in a heavily deteriorated state, in the stores of the Mdina Cathedral Museum, Malta. The object represents two zoomorphic angels holding a coat of arms. Stylistically, the artifact matches with parts of a late 16th century Organ balcony, currently exhibited at the same Museum. The present study aims to establish whether or not the newly recovered artifact might have formed part of the balcony ensemble by means of material identification techniques. The combined use of XRF, FT-IR and FT-Raman spectroscopy ensure a detailed characterization of the material used. In the case of pigments, for both artifacts the blue pigment was smalt, while cinnabar was used for red and flesh tones. The metallic decorative parts of the panels are gilded, confirmed by the presence of Au peaks in the X-ray spectra. The supporting structure of both artifacts was manufactured from poplar wood.

Detailed characterization of the early x-ray emission of a plasma produced by point-like laser irradiation of solid Al targets

2005 ◽  
Vol 12 (8) ◽  
pp. 083101 ◽  
Author(s):  
L. Labate ◽  
C. A. Cecchetti ◽  
M. Galimberti ◽  
A. Giulietti ◽  
D. Giulietti ◽  
...  
Keyword(s):  
Laser Irradiation ◽  
Detailed Characterization ◽  
X Ray

Characterization of a Lignite Ash from the Metc Gasifier I. Mineralogy

1984 ◽  
Vol 43 ◽  
Author(s):  
Gregory J. McCarthy ◽  
Lindsay P. Keller ◽  
Robert J. Stevenson ◽  
Kevin C. Galbreath ◽  
Aaron L. Steinwand
Keyword(s):  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
Operating Conditions ◽  
X Ray Diffraction ◽  
Detailed Characterization ◽  
X Ray ◽  
Large Numbers ◽  
Inorganic Constituents ◽  
Micrometer Scale

AbstractUtilization or disposal of gasification ash requires detailed characterization of its chemistry and phase formation (mineralogy). A North Dakota lignite ash produced in the Morgantown Energy Technology Center (METC) gasifier has been studied in detail by x-ray diffraction and electron microprobe analysis. The ash was coarse (84% of grains larger than 1.0 mm) but a typical grain was composed of a dozen or more crystalline phases with dimensions on the micrometer scale as well as less abundant glass phases. Hard centimeter-size clinkers suggested partial melting followed by crystallization. Silicates (dicalcium silicates (C2S), merwinite, Ca-Na-silicate (CNS), quartz), aluminosilicates (melilite, nepheline, carnegieite), oxides (ferrite spinels, periclase, hematite), calcite and minor zeolites comprised the dominant mineralogy. Microprobe analyses were obtained for large numbers of grains of the C2S phases, CNS, merwinite, melilite, ferrite spinels and calcite. The remaining phases had crystal sizes too small for analysis. A model is proposed for the genesis of this ash based on the inorganic constituents of lignite and the gasifier operating conditions.

scholarly journals Detailed Componential Characterization of Extractable Species with Organic Solvents from Wheat Straw

2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
Yong-Chao Lu ◽  
Yao Lu ◽  
Zhao-Lin Lu ◽  
Xian-Yong Wei
Keyword(s):  
Wheat Straw ◽  
Photoelectron Spectroscopy ◽  
Energy Dispersive Spectrometry ◽  
Gas Chromatography Mass Spectrometry ◽  
Detailed Characterization ◽  
X Ray ◽  
Componential Analysis ◽  
Transmission Electron ◽  
Total Extractives

Componential analysis of extractives is important for better understanding the structure and utilization of biomass. In this investigation, wheat straw (WS) was extracted with petroleum ether (PE) and carbon disulfide (CS2) sequentially, to afford extractable fractions EFPE and EFCS2, respectively. Detailed componential analyses of EFPE and EFCS2 were carried out with Fourier transform infrared (FTIR) spectroscopy, gas chromatography/mass spectrometry (GC/MS), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), energy dispersive spectrometry (EDS), and electron probe microanalysis (EPMA). Total extractives were quantified 4.96% by weight compared to the initial WS sample. FTIR and GC/MS analyses results showed that PE was effective for the extraction of ketones and waxes derived compounds; meanwhile CS2 preferred ketones and other species with higher degrees of unsaturation. Steroids were enriched into EFPE and EFCS2 with considerable high relative contents, namely, 64.52% and 79.58%, respectively. XPS analysis showed that most of the C atoms in extractives were contained in the structures of C-C, C-COOR, and C-O. TEM-EDS and EPMA analyses were used to detect trace amount elements, such as Al, Si, P, S, Cl, and Ca atoms. Detailed characterization of extractable species from WS can provide more information on elucidation of extractives in biomass.

X-Ray Characterization of Buried δ Layers

1998 ◽  
Vol 05 (01) ◽  
pp. 145-149 ◽  
Author(s):  
J. Falta ◽  
D. Bahr ◽  
G. Materlik ◽  
B. H. Müller ◽  
M. Horn-Von Hoegen
Keyword(s):  
Lattice Constant ◽  
Linear Dependence ◽  
Standing Waves ◽  
Interface Roughness ◽  
Tetragonal Distortion ◽  
Detailed Characterization ◽  
X Ray ◽  
Lattice Position

A combination of measurements of crystal truncation roda and X-ray standing waves has been used for a detailed characterization of buried Ge δ layers on Si(001). Measurements of crystal truncation rods reveal the interface roughness, the δ layer lattice constant and the δ layer concentration. From measurements with X-ray standing waves the dopant lattice position and crystallinity of the δ layer are determined. We find a linear dependence of the local tetragonal distortion of the Ge bonding in the δ layer on the Ge concentration in the layer.

scholarly journals Short-lived metal-centered excited state initiates iron-methionine photodissociation in ferrous cytochrome c

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Marco E. Reinhard ◽  
Michael W. Mara ◽  
Thomas Kroll ◽  
Hyeongtaek Lim ◽  
Ryan G. Hadt ◽  
...  
Keyword(s):  
Excited State ◽  
Heme Iron ◽  
Spin Multiplicity ◽  
X Ray ◽  
Bond Dissociation ◽  
Transfer Protein ◽  
Quintet State ◽  
Essential Step ◽  
Electron Transfer Protein ◽  
Peroxidase Enzyme

AbstractThe dynamics of photodissociation and recombination in heme proteins represent an archetypical photochemical reaction widely used to understand the interplay between chemical dynamics and reaction environment. We report a study of the photodissociation mechanism for the Fe(II)-S bond between the heme iron and methionine sulfur of ferrous cytochrome c. This bond dissociation is an essential step in the conversion of cytochrome c from an electron transfer protein to a peroxidase enzyme. We use ultrafast X-ray solution scattering to follow the dynamics of Fe(II)-S bond dissociation and 1s3p (Kβ) X-ray emission spectroscopy to follow the dynamics of the iron charge and spin multiplicity during bond dissociation. From these measurements, we conclude that the formation of a triplet metal-centered excited state with anti-bonding Fe(II)-S interactions triggers the bond dissociation and precedes the formation of the metastable Fe high-spin quintet state.

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