다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Investigations into the mechanisms governing the behavior of metal oxide gas sensors continue to be of great interest. Oxygen vacancies are a ubiquitous defect in this class of materials and their characteristics can be affected by synthesis, processing and operating parameters. The primary role of oxygen vacancies in modifying sensing performance cited in the gas sensing literature is based on a modulation of the amount of surface adsorbed oxygen or alternatively, the baseline resistance. Unfortunately, this generalized description does not provide a complete representation of the role of oxygen vacancies that would aid in more a fundamental understanding of their role in gas sensing. To this end, an attempt is made to distinguish between the role of surface and bulk oxygen vacancies where emphasis on proper characterization is first highlighted. The influence of surface oxygen vacancies on factors affecting adsorption, such as surface structure, are examined to gain understanding on improved sensing performance. The effect of bulk oxygen vacancy concentration and distribution on sensing are also discussed. Finally, the importance of these concepts within the context of doped and heterostructured gas sensors are then briefly discussed.

Role of Oxygen Vacancies in Nanostructured Metal-Oxide Gas Sensors: A Review

Preparation and characterization of GO-ZnO nanocomposite for UV detection application

ZnO/polyaniline composite based photoluminescence sensor for the determination of acetic acid vapor

High acetic acid sensing performance of Mg-doped ZnO/rGO nanocomposites

Acetic acid vapor thin film gas sensor was developed by synthesizing Mg-doped ZnO nanoparticles using a low cost and facile sol–gel route and were characterized using field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy and photoluminescence analysis. Morphological characterizations showed the formation of well-defined and highly crystalline ZnO nanoparticles on Si(100)/SiO2 substrate. Gas sensing characterization of dip coated Mg-doped ZnO thin films were performed in temperature range of 150–400 °C at different acetic acid vapor concentrations. At 300 °C, the sensitivity for pure ZnO, Zn0.98Mg0.02O and Zn0.94Mg0.06O samples at concentration of 200 ppm of acetic acid were 124, 78 and 67%, respectively. The highest sensitivity for Zn0.96Mg0.04O sample was 136% at the same vapor concentration and temperature. It showed a fast response time and recovery time (145 and 110 s, respectively).

Vahid Khorramshahi

Papers

High acetic acid sensing performance of Mg-doped ZnO/rGO nanocomposites

Acetic acid sensing of Mg-doped ZnO thin films fabricated by the sol–gel method

Response Time Enhancement of a CdS/rGO Nanocomposite-Based Photoresistor