Pyromorphite formation and stability after quick lime neutralisation in the presence of soil and clay sorbents

2007 ◽  
Vol 4 (2) ◽  
pp. 109 ◽  
Author(s):  
Mark A. Chappell ◽  
Kirk G. Scheckel
Keyword(s):  
Phosphoric Acid ◽  
Contaminated Soils ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Natural Soil ◽  
X Ray Diffraction ◽  
Quick Lime ◽  
X Ray ◽  
Soil Systems ◽  
Diffraction Patterns

Environmental context. Questions remain regarding the potential risk of human Pb exposure from metal-contaminated soils. Studies show that the risk of human exposure is more accurately linked to the toxicity of the Pb species in soil than the total quantity of Pb. This work explores the practicality of converting Pb to a less toxic, less bioavailable species called pyromorphite in the presence of soil. Abstract. Soluble Pb is immobilised in pure systems as pyromorphite by adding sources of P, but doubts remain about the effectiveness of this approach in natural soil systems, particularly given the ability of soil humic substances to interfere with Pb-mineral formation. In addition, recent thermodynamic modelling predicts that pyromorphite formed by the addition of phosphoric acid to Pb-contaminated soils, followed by neutralisation with quick lime (Ca(OH)2) will destabilise the mineral, reverting the Pb back to more soluble species such as cerussite or anglesite. In this paper, we describe experiments to form pyromorphite in the presence of two different sorbents: a reference smectite called Panther Creek Bentonite, and a commercially available, organically rich potting mixture. We present X-ray diffraction (XRD) evidence suggestive of pyromorphite formation, yet, like similar studies, the evidence is less than conclusive. Linear combination fits of Pb X-ray absorption fine-structure spectroscopy (XAFS) data collected at the Advanced Photon Source at Argonne National Laboratory show that pyromorphite is the major Pb species formed after the addition of phosphoric acid. Furthermore, XAFS data shows that neutralising with quick lime enhances (as opposed to reducing) pyromorphite content in these systems. These results call into question relying solely on XRD data to confirm or deny the existence of minerals like pyromorphite, whose complex morphology give less intense and more complicated diffraction patterns than some of the simpler Pb minerals.

Synchrotron X-ray studies of metal-organic framework M2(2,5-dihydroxyterephthalate), M = (Mn, Co, Ni, Zn) (MOF74)

2012 ◽  
Vol 27 (4) ◽  
pp. 256-262 ◽  
Author(s):  
W. Wong-Ng ◽  
J. A. Kaduk ◽  
H. Wu ◽  
M. Suchomel
Keyword(s):  
Powder Diffraction ◽  
Metal Organic Framework ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Lattice Parameter ◽  
X Ray ◽  
Metal Organic ◽  
Sorbent Materials ◽  
Diffraction Patterns ◽  
Unsaturated Metal Sites

M2(dhtp)·nH2O (M = Mn, Co, Ni, Zn; dhtp = 2,5-dihydroxyterephthalate), known as MOF74, is a family of excellent sorbent materials for CO2 that contains coordinatively unsaturated metal sites and a honeycomb-like structure featuring a broad one-dimensional channel. This paper describes the structural feature and provides reference X-ray powder diffraction patterns of these four isostructural compounds. The structures were determined using synchrotron diffraction data obtained at beam line 11-BM at the Advanced Photon Source (APS) in the Argonne National Laboratory. The samples were confirmed to be hexagonal R 3 (No. 148). From M = Mn, Co, Ni, to Zn, the lattice parameter a of MOF74 ranges from 26.131 73(4) Å to 26.5738(2) Å, c from 6.651 97(5) to 6.808 83(8) Å, and V ranges from 3948.08 Å3 to 4163.99 Å3, respectively. The four reference X-ray powder diffraction patterns have been submitted for inclusion in the Powder Diffraction File (PDF).

scholarly journals Maximum a posteriori estimation of crystallographic phases in X-ray diffraction tomography

2015 ◽  
Vol 373 (2043) ◽  
pp. 20140392 ◽  
Author(s):  
Doĝa Gürsoy ◽  
Tekin Biçer ◽  
Jonathan D. Almer ◽  
Raj Kettimuthu ◽  
Stuart R. Stock ◽  
...  
Keyword(s):  
National Laboratory ◽  
Spinous Process ◽  
Argonne National Laboratory ◽  
Three Dimensional ◽  
Polycrystalline Materials ◽  
Reconstruction Method ◽  
Diffraction Tomography ◽  
A Posteriori ◽  
X Ray Diffraction ◽  
X Ray

A maximum a posteriori approach is proposed for X-ray diffraction tomography for reconstructing three-dimensional spatial distribution of crystallographic phases and orientations of polycrystalline materials. The approach maximizes the a posteriori density which includes a Poisson log-likelihood and an a priori term that reinforces expected solution properties such as smoothness or local continuity. The reconstruction method is validated with experimental data acquired from a section of the spinous process of a porcine vertebra collected at the 1-ID-C beamline of the Advanced Photon Source, at Argonne National Laboratory. The reconstruction results show significant improvement in the reduction of aliasing and streaking artefacts, and improved robustness to noise and undersampling compared to conventional analytical inversion approaches. The approach has the potential to reduce data acquisition times, and significantly improve beamtime efficiency.

Powder X-ray diffraction of capecitabine, C15H22FN3O6

2019 ◽  
Vol 34 (3) ◽  
pp. 282-283 ◽  
Author(s):  
James A. Kaduk ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton
Keyword(s):  
Diffraction Data ◽  
Density Functional ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Acta Cryst ◽  
X Ray ◽  
Data Density ◽  
Structure Determinations

Capecitabine (Xeloda) is a chemotherapy drug used to treat breast, gastric, and colorectal cancers. Commercial capecitabine crystallizes in the orthorhombic space group P212121 (#19) with a = 5.20587(3), b = 9.52324(4), c = 34.79574(21) Å, V = 1725.062(12) Å3, and Z = 4. A reduced cell search in the Cambridge Structural Database (Groom C. R., Bruno, I. J., Lightfoot, M. P., and Ward, S. C. (2016) Crystallogr. Sect. B: Struct. Sci., Cryst. Eng. Mater.72, 171–179) yielded three previous structure determinations (Rohlicek, J., Husak, M., Gavenda, A., Jegorov, A., Kratochvil, B., and Fitch, A. (2016). Acta Cryst. Sect. E: Crystallgr. Commun.72, 879–880, BOVDUM; Malińska, M., Krzeczyński, P., Czerniec-Michalik, E., Trzcińska, K., Cmoch, P., Kutner, A., and Woźniak, K. (2014). J. Pharm. Sci.103, 587–593, BOVDUM01 and BOVDUM02), using synchrotron powder data and later single crystal data at two temperatures. In this work, the sample was ordered from United States Pharmacopeial Convention (lot # G0J205), and analyzed as-received. The room temperature (295 K) crystal structure was refined using synchrotron (λ = 0.413914 Å) powder diffraction data, density functional theory (DFT), and Rietveld refinement techniques. Hydrogen positions were included as part of the structure, and were re-calculated during the refinement. The diffraction data were collected on a beamline 11-BM at the Advanced Photon Source, Argonne National Laboratory and the powder X-ray diffraction pattern of the compound is provided. The agreement of the Rietveld-refined and DFT-optimized structures is poorest in the pentyl side chain, consistent with the disorder observed previously.

Synthesis of Porous Anodic Alumina (PAA) on Aluminum Alloy AA6061 in Mixture of Phosphoric Acid and Oxalic Acid

2016 ◽  
Vol 857 ◽  
pp. 237-241
Author(s):  
Chun Hong Voon ◽  
Bee Ying Lim ◽  
K.L. Foo ◽  
Uda Hashim ◽  
Sung Ting Sam ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Oxalic Acid ◽  
Phosphoric Acid ◽  
Anodic Alumina ◽  
Porous Anodic Alumina ◽  
X Ray Diffraction ◽  
X Ray ◽  
Interpore Distance ◽  
Diffraction Patterns ◽  
Ordered Porous

In this study, porous anodic alumina was formed on aluminum alloy AA6061 by anodizing using mixture of 0.3 M oxalic acid and phosphoric acid with concentration ranged from 0.1 M to 1.0 M. AA6061 alloys were anodized at 40 V and 25°C for 60 minutes. FESEM images show that the uniformity of the pores arrangement of porous anodic alumina decreased with the increasing concentration of phosphoric acid in the electrolyte. Well-ordered porous anodic alumina was formed in mixture of 0.3 M oxalic acid and 0.1 M phosphoric acid while disordered porous anodic alumina were formed when the concentration of phosphoric acid were in the range of 0.3 M to 1.0 M. Pore size and interpore distance were found to increase with the concentration of phosphoric acid in the mixture. X-ray diffraction patterns show that to γ-Al2O3 were formed on the surface of AA6061 after the anodizing process, regardless of the concentration of phosphoric acid in the mixture electrolyte.

scholarly journals Data-driven approach for synchrotron X-ray Laue microdiffraction scan analysis

2019 ◽  
Vol 75 (6) ◽  
pp. 876-888 ◽  
Author(s):  
Yintao Song ◽  
Nobumichi Tamura ◽  
Chenbo Zhang ◽  
Mostafa Karami ◽  
Xian Chen
Keyword(s):  
Machine Learning ◽  
National Laboratory ◽  
Machine Learning Algorithms ◽  
Data Driven ◽  
Computational Pipeline ◽  
X Ray Diffraction ◽  
X Ray ◽  
Data Driven Approach ◽  
Labeling Algorithms ◽  
Diffraction Patterns

A novel data-driven approach is proposed for analyzing synchrotron Laue X-ray microdiffraction scans based on machine learning algorithms. The basic architecture and major components of the method are formulated mathematically. It is demonstrated through typical examples including polycrystalline BaTiO3, multiphase transforming alloys and finely twinned martensite. The computational pipeline is implemented for beamline 12.3.2 at the Advanced Light Source, Lawrence Berkeley National Laboratory. The conventional analytical pathway for X-ray diffraction scans is based on a slow pattern-by-pattern crystal indexing process. This work provides a new way for analyzing X-ray diffraction 2D patterns, independent of the indexing process, and motivates further studies of X-ray diffraction patterns from the machine learning perspective for the development of suitable feature extraction, clustering and labeling algorithms.

scholarly journals Equation of state of hydrous Fo90 ringwoodite to 45 GPa by synchrotron powder diffraction

2005 ◽  
Vol 69 (3) ◽  
pp. 317-323 ◽  
Author(s):  
M. H. Manghnani ◽  
G. Amulele ◽  
J. R. Smyth ◽  
C. M. Holl ◽  
G. Chen ◽  
...  
Keyword(s):  
Equation Of State ◽  
Powder Diffraction ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
X Ray Diffraction ◽  
Third Order ◽  
X Ray ◽  
Synchrotron Powder Diffraction ◽  
Murnaghan Equation ◽  
Photon Source

AbstractThe equation of state of Fo90 hydrous ringwoodite has been measured using X-ray powder diffraction to 45 GPa at the GSECARS beam line at the Advanced Photon Source synchrotron at Argonne National Laboratory. The sample was synthesized at 1400°C and 20 GPa in the 5000 ton multi anvil press at Bayerisches Geoinstitut in Bayreuth. The sample has the formula Mg1.70Fe0.192+ Fe0.023+H0.13- Si1.00O4 as determined by electron microprobe, Fourier transform infrared and Mössbauer spectroscopies, and contains ~0.79% H2O by weight. Compression of the sample had been been measured previously to 11 GPa by single crystal X-ray diffraction. A third-order Birch-Murnaghan equation of state fit to all of the data gives V0 = 530.49±0.07 Å3, K0 = 174.6±2.7 GPa and K' = 6.2±0.6. The effect of 1% H incorporation in the structure on the bulk modulus is large and roughly equivalent to an increase in the temperature of ∼600°C at low pressure. The large value of K' indicates significant stiffening of the sample with pressure so that the effect of hydration decreases with pressure.

scholarly journals Powder X-ray diffraction of fluorometholone, C22H29FO4

2020 ◽  
Vol 35 (1) ◽  
pp. 71-72
Author(s):  
Diana Gonzalez ◽  
Joseph T. Golab ◽  
James A. Kaduk ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton
Keyword(s):  
Hydrogen Bonds ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Density Functional ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
The United States ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
X Ray

Commercial fluorometholone, CAS #426-13-1, crystallizes in the monoclinic space group P21 (#4) with a = 6.40648(2), b = 13.43260(5), c = 11.00060(8) Å, β = 92.8203(5)°, V = 945.517(5) Å3, and Z = 2. A reduced cell search in the Cambridge Structural Database yielded one previous structure determination, using single-crystal data at 292 K. In this work, the sample was ordered from the United States Pharmacopeial Convention (Lot # R032K0) and analyzed as-received. The room temperature (295 K) crystal structure was refined using synchrotron (λ = 0.412826 Å) powder diffraction data and optimized using density functional theory (DFT) techniques. Hydrogen positions were included as a part of the structure and were re-calculated during the refinement. The diffraction data were collected on beamline 11-BM at the Advanced Photon Source, Argonne National Laboratory, and the powder X-ray diffraction pattern of the compound has been submitted to ICDD® for inclusion in the Powder Diffraction File™. The agreement of the Rietveld-refined and DFT-optimized structures is excellent; the root-mean-square Cartesian displacement is 0.060 Å. In addition to the O–H⋯O hydrogen bonds observed by Park et al. (Park, Y. J., Lee, M. Y., and Cho, S. I. (1992). “Fluorometholone,” J. Korean Chem. Soc. 36, 812–817), C–H⋯O hydrogen bonds contribute to the crystal energy.

Evaluation of Freezing Methods by Low Temperature X-Ray Diffraction

1977 ◽  
Vol 35 ◽  
pp. 330-333
Author(s):  
T. Gulik-Krzywicki ◽  
M.J. Costello
Keyword(s):  
Biological Materials ◽  
Molecular Organization ◽  
X Ray Diffraction ◽  
Glass Capillary ◽  
X Ray ◽  
Rate Dependent ◽  
Before And After ◽  
Freeze Etching ◽  
Diffraction Patterns ◽  
Set Up

Freeze-etching electron microscopy is currently one of the best methods for studying molecular organization of biological materials. Its application, however, is still limited by our imprecise knowledge about the perturbations of the original organization which may occur during quenching and fracturing of the samples and during the replication of fractured surfaces. Although it is well known that the preservation of the molecular organization of biological materials is critically dependent on the rate of freezing of the samples, little information is presently available concerning the nature and the extent of freezing-rate dependent perturbations of the original organizations. In order to obtain this information, we have developed a method based on the comparison of x-ray diffraction patterns of samples before and after freezing, prior to fracturing and replication.Our experimental set-up is shown in Fig. 1. The sample to be quenched is placed on its holder which is then mounted on a small metal holder (O) fixed on a glass capillary (p), whose position is controlled by a micromanipulator.

Examination of Rabbit Fc Crystals

1968 ◽  
Vol 26 ◽  
pp. 140-141
Author(s):  
J. P. Robinson ◽  
P. G. Lenhert
Keyword(s):  
Molecular Weight ◽  
Flat Plate ◽  
Phosphate Buffer ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Neutral Ph ◽  
Small Crystals ◽  
Carbon Coated ◽  
Diffraction Patterns

Crystallographic studies of rabbit Fc using X-ray diffraction patterns were recently reported. The unit cell constants were reported to be a = 69. 2 A°, b = 73. 1 A°, c = 60. 6 A°, B = 104° 30', space group P21, monoclinic, volume of asymmetric unit V = 148, 000 A°3. The molecular weight of the fragment was determined to be 55, 000 ± 2000 which is in agreement with earlier determinations by other methods.Fc crystals were formed in water or dilute phosphate buffer at neutral pH. The resulting crystal was a flat plate as previously described. Preparations of small crystals were negatively stained by mixing the suspension with equal volumes of 2% silicotungstate at neutral pH. A drop of the mixture was placed on a carbon coated grid and allowed to stand for a few minutes. The excess liquid was removed and the grid was immediately put in the microscope.

Control of the phase composition of advanced calcium phosphates using an x-ray diffractometer with a curved position-sensitive detector

2020 ◽  
Vol 86 (6) ◽  
pp. 29-35
Author(s):  
V. P. Sirotinkin ◽  
O. V. Baranov ◽  
A. Yu. Fedotov ◽  
S. M. Barinov
Keyword(s):  
Phase Composition ◽  
Calcium Phosphates ◽  
Position Sensitive Detector ◽  
Sensitive Detector ◽  
X Ray Diffraction ◽  
X Ray ◽  
Impurity Phases ◽  
Position Sensitive ◽  
Diffraction Peaks ◽  
Diffraction Patterns

The results of studying the phase composition of advanced calcium phosphates Ca10(PO4)6(OH)2, β-Ca3(PO4)2, α-Ca3(PO4)2, CaHPO4 · 2H2O, Ca8(HPO4)2(PO4)4 · 5H2O using an x-ray diffractometer with a curved position-sensitive detector are presented. Optimal experimental conditions (angular positions of the x-ray tube and detector, size of the slits, exposure time) were determined with allowance for possible formation of the impurity phases during synthesis. The construction features of diffractometers with a position-sensitive detector affecting the profile characteristics of x-ray diffraction peaks are considered. The composition for calibration of the diffractometer (a mixture of sodium acetate and yttrium oxide) was determined. Theoretical x-ray diffraction patterns for corresponding calcium phosphates are constructed on the basis of the literature data. These x-ray diffraction patterns were used to determine the phase composition of the advanced calcium phosphates. The features of advanced calcium phosphates, which should be taken into account during the phase analysis, are indicated. The powder of high-temperature form of tricalcium phosphate strongly adsorbs water from the environment. A strong texture is observed on the x-ray diffraction spectra of dicalcium phosphate dihydrate. A rather specific x-ray diffraction pattern of octacalcium phosphate pentahydrate revealed the only one strong peak at small angles. In all cases, significant deviations are observed for the recorded angular positions and relative intensity of the diffraction peaks. The results of the study of experimentally obtained mixtures of calcium phosphate are presented. It is shown that the graphic comparison of experimental x-ray diffraction spectra and pre-recorded spectra of the reference calcium phosphates and possible impurity phases is the most effective method. In this case, there is no need for calibration. When using this method, the total time for analysis of one sample is no more than 10 min.

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