With growing industrialization in power sector, air is being polluted with a host of substances-most conspicuously with suspended particulate matter emanating from coal-fired thermal power plants. Flue gas conditioning, especially in such power plants, requires in situ generation of ammonia. In the present paper, experiments for kinetic study of hydrolysis of urea have been conducted using a borosil glass reactor, first without stirring followed by with stirring. The study reveals that conversion increases exponentially with an increase in temperature and feed concentration. Furthermore, the effect of stirring speed, temperature and concentration on conversion has been studied. Using collision theory, temperature dependency of forward rate constant has been developed from which activation energy of the reaction and the frequency factors have been calculated. It has been observed that the forward rate constant increases with an increase in temperature. The activation energy and frequency factor with stirring has been found to be 59.85 kJ/mol and 3.9 x 10(6)min(-1) respectively with correlation co-efficient and standard deviation being 0.98% and +/-0.1% in that order.
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http://dx.doi.org/10.1016/j.jhazmat.2009.10.053 | DOI Listing |
J Biosci Bioeng
January 2025
Department of Food and Bioproduct Sciences, University of Saskatchewan, 51 Campus Drive, Saskatoon, SK, S7N 5A8, Canada. Electronic address:
Starch-rich faba bean, yellow lentil, and yellow field pea flours were subjected to submerged fermentation using Aspergillus oryzae and Lactobacillus plantarum starter mono- or co-cultures, to increase protein contents of the flours. Fermentation mixes were supplemented with up to 35 g/L urea, ammonium sulfate and/or monoammonium phosphate as nitrogen sources. Protein contents of the flours increased 2-2.
View Article and Find Full Text PDFTalanta
January 2025
Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, 410081, PR China. Electronic address:
E-selectin (CD62E) is an adhesion molecule expressed on the surface of endothelial cells (ECs) and its level increases significantly upon the stimulation of ECs by inflammatory factors. Quantitative analysis of CD62E is of great importance to early diagnosis and treatment of vascular diseases and hypertension. A new method for the determination of CD62E was developed using a portable pH meter in this work.
View Article and Find Full Text PDFFood Chem
December 2024
Department of Food Chemistry, Technology and Biotechnology, Faculty of Chemistry, Gdańsk University of Technology, Gdańsk, Narutowicza Street 11/12, 80-233, Poland. Electronic address:
This study compared the effectiveness of urea-containing and urea-free L-cysteine solutions in extracting high-quality feather keratin and evaluated commercial proteases for producing keratin-derived bioactive peptides. The urea-assisted extraction was crucial for achieving high structural integrity and yield of soluble keratin. The keratin isolate exhibited oil-holding capacity of 9.
View Article and Find Full Text PDFAnal Chim Acta
February 2025
Shenzhen Key Laboratory of Synthetic Genomics, Guangdong Provincial Key Laboratory of Synthetic Genomics, CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China. Electronic address:
Background: High-precision and broad-range pH detection is critical for health status assessment, such as signal transduction, enzyme activity, endocytosis, and cell proliferation and apoptosis. Although pH-responsive ratiometric fluorescent probes offer an effective pH monitoring strategy, their preparation often requires multi-step modification and decreases fluorescence efficiency and stability. Herein, we developed a simple method to prepare fluorescent Si dots with dual emission centers for high-precision and broad-range pH monitoring, and the detection of urease based on pH-responsive Si dots and pH monitoring in living cell was further explored.
View Article and Find Full Text PDFIn this research, we report a simple fluorescent probe designed to detect thallium(iii) ions (Tl) in artificial urine samples. The Tl signaling probe (TP-1) was readily prepared from 2-acetyl-6-methoxynaphthalene and hydrazine. In a pH 4.
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