Systems containing hydrogen peroxide at high concentration Communication 15. The 10� solubility isotherm of the ternary system Ca(OH)2-H2O2-H2O and further characterization of the solid phases

1958 ◽  
Vol 7 (11) ◽  
pp. 1245-1250 ◽  
Author(s):  
S. Z. Makarov ◽  
N. K. Grigor'eva
Keyword(s):  
Hydrogen Peroxide ◽  
Ternary System ◽  
Solubility Isotherm ◽  
High Concentration ◽  
Solid Phases

CHARACTERIZATION OF A HYDROGEN PEROXIDE-BENZENE COMPLEX USING MATRIX ISOLATION INFRARED SPECTROSCOPY

2019 ◽  
Author(s):  
Jay Amicangelo ◽  
Lia Totleben ◽  
Jacob Oslosky ◽  
Yudhishtara Payagala ◽  
Catherine Kaiser ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Infrared Spectroscopy ◽  
Matrix Isolation

Synthesis and Characterization of Silver Nanoplates by a Seed-mediated Method

2019 ◽  
Vol 29 (3) ◽  
Author(s):  
Mai Ngọc Tuan Anh
Keyword(s):  
Hydrogen Peroxide ◽  
Silver Nanoparticles ◽  
Ascorbic Acid ◽  
Silver Nitrate ◽  
Sodium Borohydride ◽  
Trisodium Citrate ◽  
Synthesis And Characterization ◽  
Silver Nanoplates ◽  
Seed Mediated

Silver nanoplates (SNPs) having different size were synthesized by a seed-mediated method. The seeds -silver nanoparticles with 4 – 6 nm diameters were synthesized first by reducing silver nitrate with sodium borohydride in the present of Trisodium Citrate and Hydrogen peroxide. Then these seeds were developed by continue reducing Ag\(^+\) ions with various amount of L-Ascorbic acid to form SNPs. Our analysis showed that the concentratrion of L-Ascorbic acid, a secondary reducing agent, played an important role to form SNPs. In addition, the size and in-plane dipole plasmon resonance wavelenght of silver nanoplates were increased when the concentration of added silver nitrate increased. The characterization of SNPs were studied by UV-Vis, FE-SEM, EDS and TEM methods.

Management and engineering solutions to improve stripping equipment efficiency in Chernogorksy open pit mine

2018 ◽  
pp. 36-48
Author(s):  
G. N. Shapovalenko ◽  
S. N. Radionov ◽  
V. V. Gorbunov ◽  
V. A. Khazhiev ◽  
V. Yu. Zalyadnov ◽  
...  
Keyword(s):  
Open Pit Mine ◽  
Open Pit ◽  
High Concentration ◽  
Open Pit Mines ◽  
Blasting Operation ◽  
Internal Dump ◽  
Mining Conditions ◽  
Mining Front ◽  
Comparison Of Equipment

Chernogosky open pit mine integrates truck-and-shovel system of mining with overburden rehandling to internal dump with a set of walking excavators for rehandling of overburden to mined-out area of the pit. It is possible to improve efficiency of stripping in the conditions of Chernogorsky OPM by reducing percentage of stripping with more expensive handling system. The relevant research and solutions to this effect are presented in this article. Comparative characterization of mining conditions and parameters of mining systems applied is given for open pit mines Chernogorsky, Turnui, Nazarovsky, Vostochno-Beisky and Izykh. The comparative analysis points at the need to account for difficulty of mining and process sites in comparison of equipment productivity. High concentration of mining machines, which is conditioned by narrow mining front and simultaneous operation of five faces, as well as blasting operation implemented every 1-2 days, are recognized as the main constraints of excavator capacity in mining with direct dumping in Chernogorsky open pit mine. The management and engineering solutions implemented in the mine and resulted in higher efficiency of draglines are described.

A Simple, Green and Fast Ultraviolet Spectrophotometric Method for the Carbamide Peroxide Determination in Dental Whitening Products

2019 ◽  
Vol 15 (2) ◽  
pp. 138-144
Author(s):  
Fabiana Vieira Lima ◽  
Aline Farias ◽  
Cassiana Mendes ◽  
Simone Gonçalves Cardoso ◽  
Marcos Antônio Segatto Silva
Keyword(s):  
Hydrogen Peroxide ◽  
Pharmaceutical Products ◽  
Reference Solution ◽  
Iodometric Titration ◽  
Carbamide Peroxide ◽  
Ultraviolet Detection ◽  
Water As Solvent ◽  
Development And Validation ◽  
Dental Whitening

Background: The carbamide peroxide is the most commonly active ingredient used for home dental whitening products, its quantification in pharmaceutical products is of extreme importance due to the relation with the products potency and the previously related low carbamide peroxide stability. Once, there is only one official carbamide peroxide determination based on iodometric titration, this method is time-consuming and generates a lot of residues. The aim of this study was to carry out development and validation of a simple and fast ultraviolet spectrophotometer assay to quantify an innovative dental whitening gel. Methods: The proposed method was validated according international conference on harmonization guideline. Procedure is based on the iodide/iodine redox chemistry; iodine released through the action of hydrogen peroxide of carbamide peroxide with ultraviolet detection at 350 nm. Results: The procedure was linear in the concentration range of 1.0-4.0 µg/mL, specific to the excipients, robust for the evaluated parameters (variation of wavelength (± 5 nm); reagent addition (± 10%)), showing the results of RSD 1.88 and 0.39% respectively. Repeatability precision was RSD = 1.42%, with accurate RSD = 2.15% by adding reference solution. The assay used only water as solvent for sample preparation. In comparison to the pharmacopeial method, the latter is more time-consuming, as it generates a lot of residues, and it could not quantify small CP dosages. Conclusion: Thus, the proposed method was proved to be suitable to determine carbamide peroxide during the development and characterization of nanoparticle formulations in the present study.

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