Kinetics and mechanism of radium-isotopes dissolution in TENORM scale waste associated with petroleum production using certain organic carbon source: lactic acid solution—case study

2020 ◽  
Vol 27 (30) ◽  
pp. 38134-38147
Author(s):  
Elsayed M. El Afifi ◽  
Ahmed M. Shahr El-Din ◽  
Moustafa A. Hilal
2021 ◽  
pp. 174751982110210
Author(s):  
Xiaolong Xu ◽  
Lijuan Liu

Lactic acid is an important platform compound used as raw material for the production of lactide and polylactic acid. However, its concentration and composition distribution are not as simple as those of common compounds. In this work, the mass concentration distribution of highly concentrated lactic acid is determined by back titration. The components of highly concentrated lactic acid, crude lactide, and polymer after the reaction are analyzed by HPLC. Different concentrations of lactic acid solution were prepared for the synthesis of lactide and its content in the product was determined by 1H NMR analysis. We found that lactide is more easily produced from high-concentration lactic acid solution with which the condensed water is easier to release. Hence, the removal of condensed water is crucial to the formation of lactide, although it is not directly formed by esterification of two molecules of lactic acid.


Aquaculture ◽  
2021 ◽  
pp. 736669
Author(s):  
Rildo José Vasconcelos de Andrade Brazil ◽  
Elizabeth Pereira dos Santos ◽  
Gisely Karla de Almeida Costa ◽  
Clarissa Vilela Figueiredo Campos ◽  
Suzianny Maria Bezerra Cabral da Silva ◽  
...  

1999 ◽  
Vol 15 (6) ◽  
pp. 413-416 ◽  
Author(s):  
J.W. Nicholson ◽  
B.J. Millar ◽  
B. Czarnecka ◽  
H. Limanowska-Shaw

2021 ◽  
Vol 6 (2) ◽  
pp. 190
Author(s):  
Dewi Puspitasari ◽  
Nurah Tajjalia ◽  
Diana Wibowo ◽  
Agung Satria Wardhana

Background: Bioactive resin can release calcium ions when contact with solution media, even in acid condition. In the oral cavity, pH may change into acid condition due to the metabolic results of Streptococcus mutans. The bacteria metabolize carbohydrates into organic acids, one of which is lactic acid. Purpose: Analyze the effect of lactic acid solution and artificial saliva on the number of the release of calcium ions of bioactive resin. Methods: Forty-two specimens (diameter 15 mm x thickness 1 mm; n= 7/group fabricated with Activa™ Bioactive Restorative (Pulpdent). The specimens that meet the criteria were divided into 6 groups. The specimen was immersed for 1 and 7 days in the incubator at 37oC. The number of calcium ion release is measured using titration method. Results: Two Way Anova test and Post Hoc Bonferonni test showed there were significant differences among all group for lactic acid 1 day (4.040 ± 0.360) µg, artificial saliva 1 day (0.640 ± 0.338) µg, distilled water 1 day (1.040 ± 0.504) µg, lactic acid 7 days (5.400 ± 0.312), artificial saliva 7 days (1.640 ± 0.215) µg, distilled water 7 days (3.520± 0.356 µg). Conclusion: There was an influence of lactic acid and artificial saliva on the number of calcium ion releases of bioactive resin. Immersion of bioactive resin in the lactic acid solution increase the calcium ion releases and artificial saliva decrease the calcium ion release compared to distilled water. Keywords: artificial saliva, bioactive resin, calcium ion release, lactic acid


2012 ◽  
Vol 118 ◽  
pp. 61-66 ◽  
Author(s):  
Ana P. Abreu ◽  
Bruno Fernandes ◽  
António A. Vicente ◽  
José Teixeira ◽  
Giuliano Dragone

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