Severity: Warning
Message: file_get_contents(https://...@pubfacts.com&api_key=b8daa3ad693db53b1410957c26c9a51b4908&a=1): Failed to open stream: HTTP request failed! HTTP/1.1 429 Too Many Requests
Filename: helpers/my_audit_helper.php
Line Number: 176
Backtrace:
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 176
Function: file_get_contents
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 250
Function: simplexml_load_file_from_url
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 1034
Function: getPubMedXML
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 3152
Function: GetPubMedArticleOutput_2016
File: /var/www/html/application/controllers/Detail.php
Line: 575
Function: pubMedSearch_Global
File: /var/www/html/application/controllers/Detail.php
Line: 489
Function: pubMedGetRelatedKeyword
File: /var/www/html/index.php
Line: 316
Function: require_once
Apparent molar volumes, Vphi,2, of aqueous NaCl, NaOH, NaOD, HCl, and DCl in water and heavy water were determined at T = 523 and 573 K and p = 14 MPa with a high-temperature platinum vibrating-tube densimeter in the aquamolality range 0.25 = maq = 2.5 mol. (55.509 mol solvent)-1. The experimental results have been represented with an extended Debye-Hückel equation to describe the concentration dependence of Vphi,2 and to derive standard partial molar volumes of these electrolytes in light and heavy water, V degrees 2,H and V degrees 2,D, respectively. For NaCl and NaOH, the D2O isotope effect at infinite dilution, [V degrees 2,H - V degrees 2,D], increases from 0.2 and 0.8 cm3 mol-1 to 4.5 and 7.1 cm3 mol-1, respectively, when the temperature is increased from 523 to 573 K. For HCl and DCl, the effect is smaller and the sign is reversed, [V degrees 2,H - V degrees 2,D] = -0.7 cm3 mol-1 at 523 K and -1.4 cm3 mol-1 at 573 K. When the effect of ion association is included, the deuterium isotope effect for HCl becomes positive, [V degrees 2,H - V degrees 2,D] approximately 17 cm3 mol-1 at 573 K, consistent with NaCl and NaOH. Two models are proposed to describe the solvent isotope effect on the infinite dilution limit, one based on the Born equation and the other on the dimensionless Krichevskii parameter. The experimental values of V degrees 2,D also have been used to calculate the first reported values for the pressure dependence of the ionization constant of D2O at temperatures higher than 313 K.
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Source |
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http://dx.doi.org/10.1021/jp063824x | DOI Listing |
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