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Title: Does crystallographic anisotropy prevent the conventional treatment of aqueous mineral reactivity? A case study based on K-feldspar dissolution kinetics

Authors:
; ; ; ; ; ;
Publication Date:
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1397729
Grant/Contract Number:
AC02-05CH11231
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Geochimica et Cosmochimica Acta
Additional Journal Information:
Journal Volume: 190; Journal Issue: C; Related Information: CHORUS Timestamp: 2017-10-04 21:58:38; Journal ID: ISSN 0016-7037
Publisher:
Elsevier
Country of Publication:
United States
Language:
English

Citation Formats

Pollet-Villard, Marion, Daval, Damien, Ackerer, Philippe, Saldi, Giuseppe D., Wild, Bastien, Knauss, Kevin G., and Fritz, Bertrand. Does crystallographic anisotropy prevent the conventional treatment of aqueous mineral reactivity? A case study based on K-feldspar dissolution kinetics. United States: N. p., 2016. Web. doi:10.1016/j.gca.2016.07.007.
Pollet-Villard, Marion, Daval, Damien, Ackerer, Philippe, Saldi, Giuseppe D., Wild, Bastien, Knauss, Kevin G., & Fritz, Bertrand. Does crystallographic anisotropy prevent the conventional treatment of aqueous mineral reactivity? A case study based on K-feldspar dissolution kinetics. United States. doi:10.1016/j.gca.2016.07.007.
Pollet-Villard, Marion, Daval, Damien, Ackerer, Philippe, Saldi, Giuseppe D., Wild, Bastien, Knauss, Kevin G., and Fritz, Bertrand. 2016. "Does crystallographic anisotropy prevent the conventional treatment of aqueous mineral reactivity? A case study based on K-feldspar dissolution kinetics". United States. doi:10.1016/j.gca.2016.07.007.
@article{osti_1397729,
title = {Does crystallographic anisotropy prevent the conventional treatment of aqueous mineral reactivity? A case study based on K-feldspar dissolution kinetics},
author = {Pollet-Villard, Marion and Daval, Damien and Ackerer, Philippe and Saldi, Giuseppe D. and Wild, Bastien and Knauss, Kevin G. and Fritz, Bertrand},
abstractNote = {},
doi = {10.1016/j.gca.2016.07.007},
journal = {Geochimica et Cosmochimica Acta},
number = C,
volume = 190,
place = {United States},
year = 2016,
month =
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1016/j.gca.2016.07.007

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  • Past work on dissolution kinetics of minerals has focused on particulates and the total transfer of material to solution. The authors look instead at local topography of single crystals. Etching of quartz in alkali hydroxide solutions produces four types of features: flat-bottomed negative crystals with facets for walls, believed to nucleate on microfractures; jumbo pits, giant etch pits cored by dislocations and often with hollow cores; small pits, also believed to be dislocation-cored; and etch tunnels extending from some jumbo pits. A transition from selective etching to nonselective etching occurs as a function of ionic strength, with small pits formingmore » only at ionic strengths below {approximately}0.005 m. This transition is attributed to the decrease in Debye-Hueckel length with increasing solution strength. The authors introduce the negative crystal method, whereby dissolution rates of nominally perfect crystal faces are obtained by measuring the size of individual negative crystals during a sequence of dissolution steps. Rates are obtained to {approximately}4% accuracy, with temperature control of {plus minus} 1.25{degree}C. Using this method, they find apparent activation energies for dissolution of the prism and for an average of the rhombs to be 86.39 and 90.19 kJ/mol, respectively, with corresponding pre-exponential factors of 2.99 {times} 10{sup 9} and 1.43 {times} 10{sup 10} {mu}m/h.« less
  • No abstract prepared.
  • Purpose: To evaluate the risk of geographic miss associated with the classic four-field 'box' irradiation technique and to define the variables that predict this risk. Materials and Methods: The study population consisted of 80 patients with uterine cervix cancer seen between 2001 and 2006. Median age was 55 years (23-82 years), and 72 (90%) presented with squamous cell carcinoma. Most patients (68.7%) presented with locally advanced disease (IIb or more). Magnetic resonance imaging findings from before treatment were compared with findings from simulation of the conventional four-field 'box' technique done with rectal contrast. Study variables included tumor volume; involvement ofmore » vagina, parametrium, bladder, or rectum; posterior displacement of the anterior rectal wall; and tumor anteroposterior diameter (APD). Margins were considered adequate when the target volume (primary tumor extension, whole uterine body, and parametrium) was included within the field limits and were at least 1 cm in width. Results: Field limits were inadequate in 45 (56%) patients: 29 (36%) patients at the anterior and 28 (35%) at the posterior border of the lateral fields. Of these, 12 patients had both anterior and posterior miss, and this risk was observed in all stages of the disease (p = 0.076). Posterior displacement of the anterior rectal wall beyond S2-S3 was significantly correlated with the risk of geographic miss (p = 0.043). Larger tumors (APD 6 cm or above and volume above 50 cm{sup 3}) were also significantly correlated with this risk (p = 0.004 and p = 0.046, respectively). Conclusions: Posterior displacement of the anterior rectal wall, tumor APD, and volume can be used as guidance in evaluating the risk of geographic miss.« less