Mineral barriers against natural contamination from excavated rocks

2012 ◽  
pp. 924-929
Author(s):  
Angelica Naka ◽  
Takeshi Katsumi ◽  
Giancarlo Flores ◽  
Toru Inui ◽  
Atsushi Takai ◽  
...  
Keyword(s):  
Natural Contamination

Water decolorization using UV radiation and hydrogen peroxide: A kinetic study

2001 ◽  
Vol 44 (5) ◽  
pp. 53-60 ◽  
Author(s):  
C.A. Martín ◽  
O.M. Alfano ◽  
A.E. Cassano
Keyword(s):  
Hydrogen Peroxide ◽  
Uv Radiation ◽  
Absorption Rate ◽  
Fulvic Acids ◽  
Photon Absorption ◽  
Contaminant Concentration ◽  
Organic Substances ◽  
Mechanistic Approach ◽  
Natural Contamination ◽  
Kinetics Of

Sometimes, provision of water for domiciliary consumption faces the problem of natural contamination originated by the presence of organic substances such as humic or fulvic acids. Very often, after conventional sanitary treatments this water exhibits a persistent yellowish coloration that affects its use. Moreover, these substances may act as precursors of tri-halomethanes formation during pre-desinfection with chlorine. This paper presents, with a simplified mechanistic approach, the intrinsic reaction kinetics of natural water decolorization employing UV radiation and hydrogen peroxide. The main variables for the model are: contaminant concentration expressed as TOC, hydrogen peroxide concentration and the photon absorption rate.

Analysis of natural contamination components and sources of insulators on ±800 kV DC lines

2019 ◽  
Vol 167 ◽  
pp. 192-198
Author(s):  
Zhenghao He ◽  
Feng Gao ◽  
Zhifei Tu ◽  
Yuchan Zhang ◽  
Hui Chen
Keyword(s):  
Natural Contamination

scholarly journals Effectiveness of immobilizing agent used as a sorption layer against natural contamination

2015 ◽  
Vol 1 (4) ◽  
pp. 19-24 ◽  
Author(s):  
Jialin Mo ◽  
Toru Inui ◽  
Takeshi Katsumi ◽  
Kenji Kuninishi ◽  
Hayashi Shintaro
Keyword(s):  
Sorption Layer ◽  
Natural Contamination

Determination of Deoxynivalenol in Wheat-Based Breakfast Cereals Marketed in Portugal

2001 ◽  
Vol 64 (11) ◽  
pp. 1848-1850 ◽  
Author(s):  
MARIA LÍGIA MARTINS ◽  
H. MARINA MARTINS
Keyword(s):  
Liquid Chromatography ◽  
Detection Limit ◽  
Natural Occurrence ◽  
Fungal Metabolites ◽  
Immunoaffinity Column ◽  
Breakfast Cereals ◽  
Average Recovery ◽  
Genus Fusarium ◽  
Natural Contamination

Deoxynivalenol (DON), also known as vomitoxin, is one of a group of closely related secondary fungal metabolites—the trichothecenes—and is produced predominantly by several species of the genus Fusarium, especially Fusarium graminearum. The present study was carried out to evaluate the natural occurrence of DON in different kinds of wheat-based breakfast cereals widely consumed by the population. A total of 88 commercially available samples of wheat-based breakfast cereals were randomly collected from different supermarkets in Lisbon, Portugal. The samples were analyzed using immunoaffinity column, and DON was quantified by liquid chromatography. Detection limit was 100 μg/kg. Average recovery of DON was 80%. Of 88 analyzed samples, 72.8% contained levels of DON between 103 and 6,040 μg/kg, with mean level of 754 μg/kg, and 24 samples (27.2%) were not contaminated (<100 μg/kg). These results indicate an incidence of this mycotoxin in these products, and the authors suggest a monitoring for the prevention of molds and mycotoxins. This is the first report in Portugal on natural contamination with DON in wheat-based breakfast cereals.

Molecular Dynamics Simulations of the Conductivity of Aqueous NaCl in the Presence of Sucrose and Electric Fields

2014 ◽  
Vol 937 ◽  
pp. 200-206
Author(s):  
Xiao Gang Li ◽  
Shu Ai Yang ◽  
Ming Jun Tang ◽  
Jing Lei ◽  
Hui Hu ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Electric Fields ◽  
Ion Pairs ◽  
Water Molecules ◽  
Flashover Voltage ◽  
Low Humidity ◽  
Natural Contamination ◽  
Dynamics Simulations ◽  
Contact Ion Pairs

Various natural contamination components distributed on the surface of high-voltage insulators play important roles on the flashover hazard. Under the low humidity condition, the flashover voltage could be affected considerably by the sucrose contaminations. Molecular dynamics simulations have been carried out in order to reveal the microscopic mechanisms for the sucrose-involved flashover uptake. It is found that the diffusion of ions decreases significantly and thus the conductivity of aqueous medium is lowered apparently. In the presence of sucrose, the contact ion pairs formed between Na+ and Cl- ions are enhanced because both ions are less coordinated to water molecules. The influence of the external electric fields on the diffusion and conductivity were investigated as well. It is suggested that the sucrose contamination might lead to the uneven electric fields on the insulator surface.

The natural contamination of XP-70 insulators in Shenzhen, China

2016 ◽  
Vol 23 (1) ◽  
pp. 349-358 ◽  
Author(s):  
Jianguo Wang ◽  
Kang Wang ◽  
Mi Zhou ◽  
Ling Zhao ◽  
Senjing Yao ◽  
...  
Keyword(s):  
Natural Contamination
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