Radiation-Enhanced Aqueous Dissolution of Minerals

2011 ◽  
Vol 1298 ◽  
Author(s):  
Catherine A. Dukes ◽  
Raúl A. Baragiola
Keyword(s):  
Photoelectron Spectroscopy ◽  
Ion Irradiation ◽  
Water Immersion ◽  
Surface Concentration ◽  
Mineral Surface ◽  
X Ray ◽  
Water Exposure ◽  
Humid Environment ◽  
Water Ph ◽  
Dissolution Of Minerals

ABSTRACTMineral samples of varying petrology, exposed to ion irradiation and subsequently immersed in water or exposed to a humid environment, show up to 60% depletion of specific surface atoms (Mg, Ca, K, and Na) — a depletion that is enhanced 26,000x compared to unirradiated surfaces. Surface depletions of irradiated minerals exposed to water were measured using X-ray photoelectron spectroscopy. Irradiations were performed with 4 keV Ar+ ions at fluences from 1014 – 1019 ion cm-2; samples were subsequently exposed to liquid water or humid air (35º C and 70% RH). Analyses were done before irradiation, after irradiation, and after exposure to water, allowing identification of changes in composition due solely to ion irradiation or combined with water exposure. Before water exposure, we observe no significant change in stoichiometry of the minerals for ion fluences <1018 ions cm-2. We find incongruent depletion of 60% Mg for forsterite after exposure to humidity or three minutes (or more) water immersion. Augite undergoes reduction in the surface concentration of approximately 30% Mg, 40% Ca, and 55% Na after 1.9 x 1017 Ar cm-2 and immersion in HPLC water (pH: 6.8) for three minutes. Depth profiles of the irradiated, water exposed, minerals show that the depth of the depleted region is on the order of the ion range, ~15nm. In addition, preliminary results for albite, anorthoclase, and microcline in water show significant depletions of Na, Na and K, and K, respectively, from the mineral surface.

X-ray photoelectron spectroscopy of low surface concentration mass-selected Ag clusters

2000 ◽  
Vol 113 (20) ◽  
pp. 9233-9238 ◽  
Author(s):  
James N. O’Shea ◽  
Joachim Schnadt ◽  
Staffan Andersson ◽  
Luc Patthey ◽  
Steffen Rost ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Surface Concentration ◽  
X Ray ◽  
Ag Clusters

Characterization of Changes in Properties and Microstructure of Glassy Polymeric Carbon Following Au Ion Irradiation

2009 ◽  
Vol 1215 ◽  
Author(s):  
Malek Amir Abunaemeh ◽  
Mohamed Seif ◽  
Young Yang ◽  
Lumin Wang ◽  
Yanbin Chen ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Nuclear Reactor ◽  
Ion Irradiation ◽  
Pyrolytic Carbon ◽  
X Ray ◽  
Triso Fuel ◽  
Transmission Electron ◽  
Displacement Per Atom ◽  
Polymeric Carbon

AbstractThe TRISO fuel has been used in some of the Generation IV nuclear reactor designs [1,2]. It consists of a fuel kernel of UOx coated with several layers of materials with different functions. Pyrolytic carbon (PyC) is one of the materials in the layers. In this study we investigate the possibility of using Glassy Polymeric Carbon (GPC) as an alternative to PyC. In this work, we are comparing the changes in physical and microstructure properties of GPC after exposure to irradiation fluence of 5 MeV Au equivalent to a 1 displacement per atom (dpa) at samples prepared at 1000, 1500 and 2000°C. The GPC material is manufactured and tested at the Center for Irradiation Materials (CIM) at Alabama A&M University. Transmission electron microscopy (TEM), Rutherford backscattering spectroscopy (RBS), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy were used for the analysis.

Effect of Phosphorus on the Friction and Wear Characteristics of Cu-Sn-P Alloys

1979 ◽  
Vol 101 (2) ◽  
pp. 201-206 ◽  
Author(s):  
Y. Taga ◽  
K. Nakajima
Keyword(s):  
Photoelectron Spectroscopy ◽  
Friction And Wear ◽  
Structural Changes ◽  
Surface Concentration ◽  
Wear Characteristics ◽  
X Ray ◽  
The Matrix ◽  
Pin On Disc ◽  
The Coefficient Of Friction ◽  
Friction And Wear Characteristics

The effects of phosphorus on the friction and wear characteristics of Cu-5 at. percent Sn-P alloys containing 1–5 at. percent P were studied using a pin on disc apparatus. The results showed that the decrease in both the coefficient of friction and the rate of wear became conspicuous with the increase in quantity of Cu3P coexisting in the matrix; its amount increases with the content of phosphorus. The structural changes in the surface of the specimen due to heating in a vacuum were observed by using Auger electron spectroscopy and X-ray photoelectron spectroscopy. It was seen that the surface concentration of phosphorus strongly increased after heating at 573K, whereas the diffusion of tin atoms was markedly retarded. It was concluded from these results that the behavior of phosphorus atoms in the surface during sliding played an important role in the friction and wear characteristics of Cu-Sn-P alloys.

scholarly journals Poly(styrene/acrolein) and poly(styrene/α-tert-butoxy-ω- vinylbenzyl-polyglycidol) microspheres. Similarities and differences

e-Polymers ◽  
2002 ◽  
Vol 2 (1) ◽  
Author(s):  
Teresa Basinska
Keyword(s):  
Photoelectron Spectroscopy ◽  
Particle Surface ◽  
Surface Concentration ◽  
Covalent Immobilization ◽  
Maximal Surface ◽  
Polystyrene Microspheres ◽  
Surface Layers ◽  
X Ray ◽  
Surface Fraction ◽  
Model Protein

AbstractProperties of two types of polystyrene microspheres with polyacrolein and polyglycidol components in their surface layers are compared. Microspheres were prepared in batch radical emulsifier-free emulsion copolymerizations of styrene with acrolein and/or α-tert-butoxy-ω-vinylbenzyl-polyglycidol macromonomer ( Mn̅ = 2700). Polymerizations were initiated with potassium peroxodisulfate, and the ratio of initial concentrations of styrene and initiator was constant. Number average diameters of poly(styrene/acrolein) (P(S/A)) and of poly(styrene/polyglycidol) (P(S/PGL)) particles were in the range of 200 - 650 nm and decreased with increasing concentration of acrolein and/or polyglycidol in the polymerizing mixtures. The diameter polydispersity of synthesized particles ( Dw ̅ /Dn̅) was usually lower than 1.02. X-ray photoelectron spectroscopy for P(S/A) and P(S/PGL) microspheres showed that surface layers of particles were significantly enriched in polyacrolein or polyglycidol segments, surface fractions of which increased with increasing concentration of the more hydrophilic comonomer in the polymerizing mixture. In the case of P(S/A) particles, the maximal fraction of polyacrolein approached 80 mol-%, whereas for P(S/PGL) particles the maximal surface fraction of PGL was 42 mol-%. Human serum albumin was used as a model protein for studies of attachment onto P(S/A) and P(S/PGL) microspheres. It has been found that for both kinds of particles, the maximal surface concentration of attached (adsorbed and/or covalently immobilized) protein decreased with increasing fraction of hydrophilic component in the particle surface layer (polyacrolein or polyglycidol units). In the case of P(S/A) particles, adsorption always accompanied covalent immobilization of proteins. To the contrary, covalent immobilization of proteins onto the P(S/PGL) microspheres proceeded without adsorption of proteins.

A highly active K/Cu-Mn-O catalyst for the removal of nitric oxide in indoor air

2017 ◽  
Vol 28 (1) ◽  
pp. 7-16 ◽  
Author(s):  
Chan Wang ◽  
Feng Li ◽  
Zishu Sun ◽  
Qijun Song
Keyword(s):  
Nitric Oxide ◽  
Indoor Air ◽  
Photoelectron Spectroscopy ◽  
Elimination Rate ◽  
Surface Concentration ◽  
Precipitation Method ◽  
X Ray ◽  
Highly Active ◽  
Metal Nitrates ◽  
Co Precipitation

Nitric oxide is a frequently encountered pollutant in indoor air. It could have a number of harmful effects on human health even at low concentration. Aiming to improve the indoor air quality, an environment-friendly method was developed for the elimination of nitric oxide at ppm level based on a low temperature effective catalyst potassium-doped copper–manganese oxide (K/Cu-Mn-O). The catalyst was obtained through a co-precipitation method using metal nitrates in aqueous solution and the precipitate was calcinated at 400℃ for 5 h. After impregnation with K, the best catalytic activity was observed for the K/Cu-Mn-O catalyst with a Cu/Mn ratio of 1:2 and surface concentration of doping K 7.03% (7.4 mg/g). The composition and the structure of the catalyst were comprehensively characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and Brunauer–Emmett–Teller. The results showed that the potassium doping improved the adsorption ability of catalyst, and promoted the formation of the nitrate salt, and thereby further improved the elimination rate of nitric oxide. Finally, the possible reaction mechanisms are discussed.

scholarly journals Evolution of Cu(In,Ga)Se 2 surfaces under water immersion monitored by X‐ray photoelectron spectroscopy

2020 ◽  
Vol 52 (12) ◽  
pp. 975-979
Author(s):  
Solène Béchu ◽  
Muriel Bouttemy ◽  
Jackie Vigneron ◽  
Daniel Lincot ◽  
Jean‐François Guillemoles ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Water Immersion ◽  
X Ray

Cell Adhesion to Ion Implanted Titanium

1987 ◽  
Vol 110 ◽  
Author(s):  
K. S. Grabowski ◽  
C. R. Gossett ◽  
F. A. Young ◽  
J. C. Keller
Keyword(s):  
Photoelectron Spectroscopy ◽  
Culture Medium ◽  
Preliminary Investigation ◽  
Surface Concentration ◽  
X Ray ◽  
Commercially Pure ◽  
Fibroblast Adhesion ◽  
Tissue Culture Plate ◽  
Elastic Backscattering ◽  
Ion Implanted

AbstractThis preliminary investigation evaluates the influence of ion implantation on tissue adhesion by measuring the tendency of fibroblasts to attach to the surface of ion implanted Ti. For this work, polished specimens of commercially pure Ti were implanted with ions of Ti, Ca, C, or N to produce a surface concentration of the implanted element up to about 25 at. %. Unimplanted and ASTM treated Ti, and tissue culture plate specimens were prepared as controls. Specimens were sterilized, then exposed for 15 min. to a culture medium containing about 100,000 fibroblasts. The solution and loose fibroblasts were rinsed away and the fibroblasts counted to determine those left attached. The influence of the different implantation protocols on fibroblast adhesion to Ti will be described. Analysis of the structure and composition of the ion implanted surfaces was obtained by scanning electron microscopy, x-ray photoelectron spectroscopy, and elastic backscattering spectrometry of energetic He ions.

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