scholarly journals Chemical Etching Behavior and Mechanism of Undoped GaAs in Tartaric Acid - hydrogen Peroxide Solution Systems

2004 ◽  
Vol 72 (6) ◽  
pp. 466-470
Author(s):  
Kazuhiro SHIGYO ◽  
Sonoko UMEMURA ◽  
Kazumasa KAWASE
2009 ◽  
Vol 59 (12) ◽  
pp. 1400-1404
Author(s):  
Marius Tudorascu ◽  
Spiridon Oprea ◽  
Afrodita Doina Marculescu ◽  
Stefania Tudorascu

The mechanism of the enzymatic iodination process of diethylmaleate and diethylfumarate (which present no miscibility with water) in the presence of lactoperoxidase, both in diluted hydrogen peroxide solution and in a generating system of hydrogen peroxide using ammonium and calcium iodides as halide sources in disperse system (after an ultrasonic pretreatment) was studied. The obtained sole product (diethyl-2, 3-diiodosuccinate) after the enzymatic iodination process was directly hydrolyzed to a tartaric acid present in an optically inactive form. The mechanism of obtaining the intermediate and final products and respectively, the existence of both D, L-tartaric acid and meso-tartaric acids (as lithium bitartrates) were also investigated.


PEDIATRICS ◽  
1990 ◽  
Vol 85 (4) ◽  
pp. 593-594
Author(s):  
WAYNE R. RACKOFF ◽  
DAVID F. MERTON

Gas embolism to the portal venous system is a well-recognized radiographic sign in infants with necrotizing enterocolitis. It also has been seen after colonic irrigation with hydrogen peroxide solution.1,2 We present what we believe is the first reported patient with radiographic evidence of portal venous gas embolism after ingestion of hydrogen peroxide solution. This finding is important because gas embolism to the portal venous system after colonic irrigation with hydrogen peroxide has been associated with gangrenous and perforated bowel.1,2 CASE REPORT A 2-year-old boy ingested an unknown amount of 3% hydrogen peroxide solution. The child was found with foam around his mouth.


Author(s):  
Juraj Michálek ◽  
Kseniya Domnina ◽  
Veronika Kvorková ◽  
Kristína Šefčovičová ◽  
Klaudia Mončeková ◽  
...  

Abstract The usage of the low-cost catalysts for methylene blue removal from wastewater was investigated. Heterogeneous Fenton-like process consists of the use of a hydrogen peroxide solution, and an iron-rich catalyst, red mud and black nickel mud were used for that purpose. The factors such as the catalyst dose and the hydrogen peroxide solution volume were monitored. The results of experiments showed that the degradation of methylene blue dye in Fenton-like oxidation process using selected catalysts can be described by a pseudo-second-order kinetic model. The highest dye removal efficiency (87.15 %) was achieved using the black nickel mud catalyst after 30 minutes of reaction.


2018 ◽  
Vol 15 (30) ◽  
pp. 12-18
Author(s):  
G. D. LEIROSE ◽  
M-F GRENIER-LOUS TALOT ◽  
A. H. OLIVEIRA

Natural substances are the basis of many types of industries and represent a growing market. The study of these products and the development of analytical methods should accompany this growth to ensure quality and provenance to consumers. An example to be discussed is the L(+)-Tartaric acid, an organic compound of molecular formula C4H6O6. This organic acid is widely applied in wine, food and pharmaceutical industry. It is obtained naturally through the fermentation of fruits, especially grape and tamarind. Synthetically, there are two ways of obtaining L(+)-tartaric acid on industrial scale. It can be synthesized by the reaction of maleic anhydride with hydrogen peroxide, which is derived from petroleum by-products. And by biotechnological synthesis, in which cis-epoxy succinic acid, also derived from petroleum, is converted into L(+)-tartaric acid by hydrolase enzyme. The market for tartaric acid is growing and is considered promising. Currently, there is a lack of legislation and specific rules that allow classification of tartaric acid according to its origin. This legal vacuum precludes quality assurance for the consumer. This lack of safety is a matter of great concern as applications of tartaric acid come directly to final consumer.


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