scholarly journals Selective Detection of NO and NO2 with CNTs-Based Ionization Sensor Array

Micromachines ◽  
2018 ◽  
Vol 9 (7) ◽  
pp. 354 ◽  
Author(s):  
Hui Song ◽  
Kun Li ◽  
Chang Wang

The accurate detection of NOx is an important issue, because nitrogen oxides are not only environmental pollutants, but also harm to human health. An array composed of two carbon nanotubes (CNTs)-based ionization sensors with different separations is proposed for NO and NO2 selective detection. The experimental results indicate that the CNTs-based ionization sensor has an intrinsic, monotonically decreasing response to NO or NO2. The sensor with 80 µm separations and 100 µm separations exhibited the highest sensitivity of −0.11 nA/ppm to 300 ppm NO and −0.49 nA /ppm to 70 ppm NO2, respectively. Although the effect of the NO2 concentration on the NO response is much stronger than that of NO on NO2, the array of these two sensors still exhibits the ability to simultaneously detect the concentrations of NO and NO2 in a gas mixture without component separation.

Author(s):  
G. A. Sofronov ◽  
E. L. Patkin

One of the complex problems of modern experimental toxicology remains the molecular mechanism of formation of human health disorders separated at different time periods from acute or chronic exposure to toxic environmental pollutants (ecotoxicants). Identifying and understanding what epigenetic changes are induced by the environment, and how they can lead to unfavorable outcome, are vital for protecting public health. Therefore, we consider it important a modern understanding of epigenetic mechanisms involved in the life cycle of mammals and assess available data on the environmentally caused epigenetic toxicity and, accordingly fledging epigenenomic (epigenetic) regulatory toxicology.


2000 ◽  
Vol 09 (04) ◽  
pp. 481-503 ◽  
Author(s):  
YA-PING SUN ◽  
JASON E. RIGGS ◽  
KEVIN B. HENBEST ◽  
ROBERT B. MARTIN

Optical limiters based on several different classes of nanomaterials are reviewed. The systems under consideration include metal and semiconductor nanoparticles and nanoscale carbon materials. For the latter, the optical limiting properties of carbon nanoparticles, fullerenes, and suspended and solubilized carbon nanotubes are summarized and compared. Mechanistic implications of the available experimental results are discussed in terms of the comparison between nonlinear scattering versus nonlinear absorption as the dominating optical limiting mechanism for different nanomaterials and for different physico-chemical states of a nanomaterial.


2011 ◽  
Vol 15 (2) ◽  
pp. 565-570 ◽  
Author(s):  
Mahmoud Jafari ◽  
Majid Vaezzadeh ◽  
Momhamad Mansouri ◽  
Abazar Hajnorouzi

In this paper, the thermal conductivity of Single-wall carbon nanotubes (SWCNTs) is determined by lattice vibrations (phonons) and free elections. The thermal conductivity of SWCNTs is modeled up to 8-300 K and the observed deviations in K-T figures of SWCNTs are explained in terms of phonon vibrations models. An suitable theoretical model is shown for thermal conductivity behavior with respect to temperature and is generalized for experimental results. This model enables us to calculate thermal conductivity SWNTs and Thermal Potential Energy (TPE).


2021 ◽  
Author(s):  
Sunil Kumar ◽  
Abhay Nanda Srivastva

Carbon nanomaterials (CNMs), especially carbon nanotubes and graphene, have been attracting tremendous attention in environmental analysis for rapid and cost effective detection of various analytes by electrochemical sensing. CNMs can increase the electrode effective area, enhance the electron transfer rate between the electrode and analytes, and/or act as catalysts to increase the efficiency of electrochemical reaction, detection, adsorption and removal are of great significance. Various carbon nanomaterials including carbon nanotubes, graphene, mesoporous carbon, carbon dots exhibited high adsorption and detection capacity. Carbon and its derivatives possess excellent electro catalytic properties for the modified sensors, electrochemical methods usually based on anodic stripping voltammetry at some modified carbon electrodes. Metal electrode detection sensitivity is enhanced through surface modification of working electrode (GCE). Heavy metals have the defined redox potential. A remarkable deal of efficiency with the electrochemical sensors can be succeeded by layering the surface of the working electrode with film of active electro-catalytic species. Usually, electro catalysts used for fabrication of sensors are surfactants, nano-materials, polymers, carbon-based materials, organic ligands and biomaterials.


2011 ◽  
Vol 239-242 ◽  
pp. 1670-1673 ◽  
Author(s):  
Lei Li ◽  
Biao Ma ◽  
Qiang Li ◽  
Guo Jie Huang

Traditional lead brass is gradually prevented from application by many countries’ governments because lead does harm to human health and pollutes the environment. New types of environment-friendly lead-free brass with favorable machinability are urgently demanded in the electrical, electronics and plumping fields. Lead-free Mg-Sb brass was fabricated in present. Experimental results showed that when the content of Mg is 1.0wt%, Sb is 0.8wt% and Cu is 58.0~59.0wt%, the alloy’s mechanical properties and machinability are favorable for industry application. With the increase of the content of Sb, the machinability increased, while the mechanical properties decreased. Lots of Cu2Mg and Cu9Sb2 particles on the order of microns exist in the inner-grain and grain boundaries. These particles improve the machinability, however, lower the tensile strength and the elongation. A three-way pipe joint was successfully punched with the fabricated Mg-Sb brass bar, and this demonstrated that the fabricated Mg-Sb brass possesses favorable hot working property.


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