scholarly journals The Challenges of Prolonged Gas Sensing in the Modern Urban Environment

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5189
Author(s):  
Shai Kendler ◽  
Asaf Zuck
Keyword(s):  
Air Pollution ◽  
Urban Population ◽  
Gas Sensing ◽  
Industrial Applications ◽  
Pollution Levels ◽  
Deployment Strategy ◽  
Sensing Applications ◽  
Ongoing Effort ◽  
Dust Separator ◽  
Consistent Performance

The increase in the urban population is impacting the environment in several ways, including air pollution due to emissions from automobiles and industry. The reduction of air pollution requires reliable and detailed information regarding air pollution levels. Broad deployment of sensors can provide such information that, in turn, can be used for the establishment of mitigating and regulating acts. However, a prerequisite of such a deployment strategy is using highly durable sensors. The sensors must be able to operate for long periods of time under severe conditions such as high humidity, solar radiation, and dust. In recent years, there has been an ongoing effort to ruggedize sensors for industrial applications with an emphasis on elevated temperature, humidity, and pressure. Some of these developments are adapted for urban air sensing applications. However, protection from dust is based on filters that have not been modified in the last few decades. Such filters clog over time, thus requiring frequent replacement. This editorial presents the need for a consumable-free dust removal device that provides consistent performance without affecting the sensing process. A specific solution for removing dust using a cyclone dust separator is presented. The cyclone dust separator is implemented as an add-on module to protect commercially available sensors.

scholarly journals Quantifying the impact of air pollution on the urban population of Brazil

2007 ◽  
Vol 23 (suppl 4) ◽  
pp. S529-S536 ◽  
Author(s):  
Izabel Marcilio ◽  
Nelson Gouveia
Keyword(s):  
Air Pollution ◽  
Urban Population ◽  
Hospital Admissions ◽  
Age Groups ◽  
The Elderly ◽  
Impact Factors ◽  
Pollution Levels ◽  
Time Series Studies ◽  
The Impact ◽  
Respiratory Causes

This study aimed to quantify air pollution impact on morbidity and mortality in the Brazilian urban population using locally generated impact factors. Concentration-response coefficients were used to estimate the number of hospitalizations and deaths attributable to air pollution in seven Brazilian cities. Poisson regression coefficients (beta) were obtained from time-series studies conducted in Brazil. The study included individuals 65 years old and over and children under five. More than 600 deaths a year from respiratory causes in the elderly and 47 in children were attributable to mean air pollution levels, corresponding to 4.9% and 5.5% of all deaths from respiratory causes in these age groups. More than 4,000 hospital admissions for respiratory conditions were also attributable to air pollution. These results quantitatively demonstrate the currently observed contribution of air pollution to mortality and hospitalizations in Brazilian cities. Such assessment is thought to help support the planning of surveillance and control activities for air pollution in these and similar areas.

NiCo2O4 Nanosheets for High Performances Formaldehyde Gas Sensing Performances

2021 ◽  
Vol 16 (2) ◽  
pp. 288-292
Author(s):  
Haihui Zhang ◽  
Nabi Ullah ◽  
Mudassar Abbas ◽  
Sumaira Naeem ◽  
Mirza Nadeem Ahmad ◽  
...  
Keyword(s):  
Surface Area ◽  
Gas Sensing ◽  
Environmental Safety ◽  
Industrial Applications ◽  
Potential Candidate ◽  
Hydrothermal Route ◽  
Sensing Applications ◽  
Gas Sensing Properties ◽  
Temperature Ranges ◽  
Nico2o4 Nanosheets

The advancements in gas sensors application with maximum performances in selectivity, response, accuracy in resistance measurements and inexpensive fabrication cost has led researcher to develop and new outstand nanomaterials for environmental safety. In this study, we followed a simple hydrothermal route to synthesize ultrathin NiCo2O4 nanosheets used in gas sensing applications. The wide surface area of nanosheets provides plenty of surface area for the adsorption of HCHO gas molecules. The nanostructures are testified using XRD, XPS, SEM and TEM, respectively. The nanosheets are tested for diverse gases at assorted effective temperature ranges, and shows high response and selectivity towards formaldehyde gas. The outstanding gas-sensing properties of ultrathin NiCo2O4 nanosheets based sensor make it a potential candidate in industrial applications.

scholarly journals Development of Polymethylmethacrylate Based Composite for Gas Sensing Application

2011 ◽  
Vol 8 (s1) ◽  
pp. S165-S170 ◽  
Author(s):  
S. Devikala ◽  
P. Kamaraj
Keyword(s):  
Thick Film ◽  
Gas Sensor ◽  
Gas Sensing ◽  
Conductive Polymer ◽  
Health And Safety ◽  
Industrial Applications ◽  
Dihydrogen Phosphate ◽  
Ammonium Dihydrogen Phosphate ◽  
Sensing Applications ◽  
Oxide Composites

Gas detection instruments are increasingly needed for industrial health and safety, environmental monitoring and process control. Conductive polymer composites have various industrial applications. The composite prepared by mixing carbon black with polymethylmethacrylate (PMMA) has very good gas sensing applications. The gas sensors based on carbon nanotube/polymer, ceramic and metal oxide composites such as epoxy, polyimide, PMMA / Barium titanate and tin oxide have also been developed. In the present work, a new composite has been prepared by using PMMA and ammonium dihydrogen phosphate (ADP). The PMMA/Ammonium dihydrogen phosphate (PMADP) composites PMADP 1 and PMADP 2 were characterized by using Powder XRD. The thick films of the composite on glass plates were prepared by using a spin coating unit at 9000 rpm. The application of the thick film as gas sensor has been studied between 0 and 2000 seconds. The results reveal that the thick film of PMADP composite can function as a very good gas sensor.

Effect of Grain Size on Strain in a Copper Oxide Nanofilm for Gas Sensing Applications

2019 ◽  
Vol 11 (5) ◽  
pp. 05040-1-05040-4
Author(s):  
Sumanta Kumar Tripathy ◽  
◽  
Sanjay Kumar ◽  
Divya Aparna Narava ◽  
◽  
...  
Keyword(s):  
Grain Size ◽  
Copper Oxide ◽  
Gas Sensing ◽  
Sensing Applications

scholarly journals Optimization of a Low-Power Chemoresistive Gas Sensor: Predictive Thermal Modelling and Mechanical Failure Analysis

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 783 ◽  
Author(s):  
Andrea Gaiardo ◽  
David Novel ◽  
Elia Scattolo ◽  
Michele Crivellari ◽  
Antonino Picciotto ◽  
...  
Keyword(s):  
Low Power ◽  
Failure Analysis ◽  
Gas Sensors ◽  
High Performance ◽  
Gas Sensing ◽  
Mechanical Failure ◽  
Sensing Applications ◽  
Theoretical Approaches ◽  
Sensing Material ◽  
Silicon Bulk

The substrate plays a key role in chemoresistive gas sensors. It acts as mechanical support for the sensing material, hosts the heating element and, also, aids the sensing material in signal transduction. In recent years, a significant improvement in the substrate production process has been achieved, thanks to the advances in micro- and nanofabrication for micro-electro-mechanical system (MEMS) technologies. In addition, the use of innovative materials and smaller low-power consumption silicon microheaters led to the development of high-performance gas sensors. Various heater layouts were investigated to optimize the temperature distribution on the membrane, and a suspended membrane configuration was exploited to avoid heat loss by conduction through the silicon bulk. However, there is a lack of comprehensive studies focused on predictive models for the optimization of the thermal and mechanical properties of a microheater. In this work, three microheater layouts in three membrane sizes were developed using the microfabrication process. The performance of these devices was evaluated to predict their thermal and mechanical behaviors by using both experimental and theoretical approaches. Finally, a statistical method was employed to cross-correlate the thermal predictive model and the mechanical failure analysis, aiming at microheater design optimization for gas-sensing applications.

scholarly journals Advanced development of metal oxide nanomaterials for H2 gas sensing applications

2021 ◽  
Author(s):  
Yushu Shi ◽  
Huiyan Xu ◽  
Tongyao Liu ◽  
Shah Zeb ◽  
Yong Nie ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Gas Sensors ◽  
Gas Sensing ◽  
The Past ◽  
Sensing Applications ◽  
The Future ◽  
Metal Oxide Nanomaterials ◽  
Nanomaterials Synthesis ◽  
Advanced Development

The scheme of the structure of this review includes an introduction from the metal oxide nanomaterials’ synthesis to application in H2 gas sensors—a vision from the past to the future.

scholarly journals Transforming Pt-SnO2 Nanoparticles into Pt-SnO2 Composite Nanoceramics for Room-Temperature Hydrogen-Sensing Applications

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2123
Author(s):  
Ming Liu ◽  
Caochuang Wang ◽  
Pengcheng Li ◽  
Liang Cheng ◽  
Yongming Hu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Gas Sensing ◽  
Sintering Temperature ◽  
Sno2 Nanoparticles ◽  
Hydrogen Sensing ◽  
Sensing Applications ◽  
Nanostructured Metal Oxides ◽  
Low Dimensional ◽  
Sensing Characteristics ◽  
Nanostructured Metal

Many low-dimensional nanostructured metal oxides (MOXs) with impressive room-temperature gas-sensing characteristics have been synthesized, yet transforming them into relatively robust bulk materials has been quite neglected. Pt-decorated SnO2 nanoparticles with 0.25–2.5 wt% Pt were prepared, and highly attractive room-temperature hydrogen-sensing characteristics were observed for them all through pressing them into pellets. Some pressed pellets were further sintered over a wide temperature range of 600–1200 °C. Though the room-temperature hydrogen-sensing characteristics were greatly degraded in many samples after sintering, those samples with 0.25 wt% Pt and sintered at 800 °C exhibited impressive room-temperature hydrogen-sensing characteristics comparable to those of their counterparts of as-pressed pellets. The variation of room-temperature hydrogen-sensing characteristics among the samples was explained by the facts that the connectivity between SnO2 grains increases with increasing sintering temperature, and Pt promotes oxidation of SnO2 at high temperatures. These results clearly demonstrate that some low-dimensional MOX nanocrystals can be successfully transformed into bulk MOXs with improved robustness and comparable room-temperature gas-sensing characteristics.

scholarly journals Recent Advances in ZnO-Based Carbon Monoxide Sensors: Role of Doping

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4425
Author(s):  
Ana María Pineda-Reyes ◽  
María R. Herrera-Rivera ◽  
Hugo Rojas-Chávez ◽  
Heriberto Cruz-Martínez ◽  
Dora I. Medina
Keyword(s):  
Carbon Monoxide ◽  
High Performance ◽  
Gas Sensing ◽  
Experimental Studies ◽  
Electrical Performance ◽  
Long Term Stability ◽  
Sensing Applications ◽  
Recent Advances ◽  
Sensitivity And Selectivity ◽  
Doped Zno

Monitoring and detecting carbon monoxide (CO) are critical because this gas is toxic and harmful to the ecosystem. In this respect, designing high-performance gas sensors for CO detection is necessary. Zinc oxide-based materials are promising for use as CO sensors, owing to their good sensing response, electrical performance, cost-effectiveness, long-term stability, low power consumption, ease of manufacturing, chemical stability, and non-toxicity. Nevertheless, further progress in gas sensing requires improving the selectivity and sensitivity, and lowering the operating temperature. Recently, different strategies have been implemented to improve the sensitivity and selectivity of ZnO to CO, highlighting the doping of ZnO. Many studies concluded that doped ZnO demonstrates better sensing properties than those of undoped ZnO in detecting CO. Therefore, in this review, we analyze and discuss, in detail, the recent advances in doped ZnO for CO sensing applications. First, experimental studies on ZnO doped with transition metals, boron group elements, and alkaline earth metals as CO sensors are comprehensively reviewed. We then focused on analyzing theoretical and combined experimental–theoretical studies. Finally, we present the conclusions and some perspectives for future investigations in the context of advancements in CO sensing using doped ZnO, which include room-temperature gas sensing.

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