Spectrophotometric evaluation of stability constants of 1 : 1 weak complexes from mole ratio data using the bilogarithmic hyperbolic cosine method

AbstractPost closure radioactive release scenarios from geologic salt formation, such as the WIPP (Waste Isolation Pilot Plant) (USA) include hydrologic transport of radionuclides through a chloride saturated aquifer. Consequently, the understanding of actinide solution chemistry in brines is essential for modeling requiring accurate knowledge of the interaction between AnO22+ and chloride ions. Complexation constants of two U(VI) chloride species UO2Cl+ and UO2Cl20 have been intensively studied for about 40 years using different methods. However, large uncertainties reflect the general difficulty in determining accurate stability constants of weak complexes. In order to model the behavior of U(VI) in brines, we studied the formation of its chloride complexes by UV-Vis spectroscopy as a function of the NaCI concentration at 25 °C. The experiments were performed at constant ionic strength by varying the concentration ratio of NaCI and NaClO4. Deconvolution resulted in single component absorption sepectrum for UO2Cl+ and UO2Cl20. The apparent stability constants of UO2Cl+ and UO2Cl20 are determined at different ionic strengths. The experimental data are used to parameterize using the SIT approach.

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The calculation of stability constants of weak complexes from spectrophotometric data

Journal of Inorganic and Nuclear Chemistry ◽

10.1016/0022-1902(72)80538-4 ◽

1972 ◽

Vol 34 (6) ◽

pp. 1885-1890 ◽

Cited By ~ 22

Author(s):

P. Gans ◽

H.M.N.H. Irving

Keyword(s):

Stability Constants ◽

Weak Complexes ◽

Spectrophotometric Data

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Determination of stability constants for complexes from catalytic linear scan voltammetric currents

Journal de Chimie Physique ◽

10.1051/jcp:1998231 ◽

1998 ◽

Vol 95 (5) ◽

pp. 1091-1100 ◽

Cited By ~ 3

Author(s):

J. L. Muñiz Alvarez ◽

J. A. García Calzón ◽

J. M. López Fonseca

Keyword(s):

Stability Constants

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Changes in the Humic Acid–Metal Complexation Characteristics Depending on Humification Degree / Humīnskābju – Metālu Kompleksveidošanās Rakstura Izmaiņas Atkarībā No Humifikācijas Pakāpes

Latvian Journal of Chemistry ◽

10.2478/v10161-012-0012-0 ◽

2012 ◽

Vol 51 (3) ◽

pp. 228-237

Author(s):

D. Dudare ◽

M. Klavins

Keyword(s):

Humic Acid ◽

Stability Constants ◽

Humic Acids ◽

Complex Stability ◽

Peat Layer ◽

Raised Bog ◽

Complexing Capacity ◽

Humification Degree ◽

Complexation Process ◽

Complex Stability Constants

The aim of this study is to determine the Cu(II) complexing capacity and stability constants of Cu(II) complexes of humic acids isolated from two well-characterized raised bog peat profiles in respect to the basic properties and humification characteristics of the studied peats and their humic acids. The complex stability constants significantly change within the studied bog profiles and are well correlated with the age and decomposition degree of the peat layer from which the humic acids have been isolated. Among factors that influence this complexation process, molecular mass and ability to form micellar structures (supramolecules) of humic substances are of key importance.

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ANALISIS RASIO LEVERAGE UNTUK MEMPREDIKSI PERTUMBUHAN LABA PERUSAHAAN MANUFAKTUR SUB SEKTOR MAKANAN DAN MINUMAN YANG TERDAFTAR DI BURSA EFEK INDONESIA PERIODE 2011-2015

JBMI (Jurnal Bisnis, Manajemen, dan Informatika) ◽

10.26487/jbmi.v15i2.3530 ◽

2018 ◽

Vol 15 (2) ◽

pp. 147-172

Author(s):

Makiwan Gischanovelia

Keyword(s):

Purposive Sampling ◽

Ratio Data ◽

Equity Ratio

ABSTRAKTujuan dilakukannya penelitian adalah untuk memprediksi pertumbuhan laba perusahaan manufaktur sub sektor makanan dan minuman yang terdaftar di Bursa Efek Indonesia periode 2011-2015 melalui analisis rasio leverage yaitu Debt to asset ratio, Debt to equity ratio, Long term debt to equity ratio . Data penelitian yang digunakan merupakan data sekunder, dimana data diperoleh secara tidak langsung dari pihak ketiga atau melalui dokumen. Sumber data penelitian ini diperoleh dari internet melalui situs resmi Bursa Efek Indonesia (BEI) www.idx.co.id berupa laporan tahunan perusahaan manufaktur sub sektor makanan dan minuman di bursa efek indonesia periode 2011-2015. Sampel penelitian yang digunakan sebanyak 7 perusahaan manufaktur sub sektor makanan dan minuman. Dengan menggunakan metode purposive sampling. Teknik analisis data yang digunakan adalah Uji asumsi klasik, regresi linear berganda, uji t, uji F dan koefisien determinasi (R² ). Hasil yang diperoleh dalam penelitian ini, Variabel DAR diperoleh hasilt = -0,804 dan sig = 0,428. Karena nilai sig 0,428 > 0,05 maka terdapat pengaruh tidak signifikan terhadap pertumbuhan laba. Variabel DER diperoleh hasil t= 1,036 dan sig = 0,308. Karena nilai sig 0,308 > 0,05 maka terdapat pengaruh tidak signifikan terhadap pertumbuhan laba. Variabel LtDER diperoleh hasil t= 3,268 dan sig = 0,003. Karena nilai sig 0,003 < 0,05 maka terdapat pengaruh signifikan terhadap pertumbuhan laba. Dari pengujian secara simultan diperoleh hasil F= 6,706 dan sig = 0,001 maka variabel Debt to asset ratio, Debt to equity ratio, Long term debt to equity ratio berpengaruh signifikan terhadap pertumbuhan laba secara simultan atau bersama-sama mampu menjelaskan perubahan pada variabel dependen yaitu pertumbuhan Laba.Kata kunci : Rasio Leverage, Debt to asset ratio, Debt to equity ratio, Long term debt to equity ratio dan Pertumbuhan Laba.

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