The design and optimization of nanostructure-based surface acoustic wave (SAW) gas sensor is analyzed based on TiO2 sensing layer and modified electrode dimensions. The sensitivity of the gas sensor depends upon the type of sensing layer used and active surface area obtained by varying the aspect ratio. The performance of the sensor is observed from 0.1ppm to 100ppm concentration of ...

Together with water vapour and carbon dioxide (CO2), methane (CH4) is an important greenhouse gas, because of its strong global warming potential of 23×CO2 on a 100year time scale. The atmospheric mixing ratio of CH4 has increased with 151 ± 25%, since pre-industrial times. About 60% of the global CH4 emission is of antropogenous origin. From the natural sources (wetlands, termites, oceans, CH4...

Ruminant animals (domesticated or wild) emit methane (CH4) through enteric fermentation in their digestive tract and from decomposition of manure during storage. These processes are the major sources of greenhouse gas (GHG) emissions from animal production systems. Techniques for measuring enteric CH4 vary from direct measurements (respiration chambers, which are highly accurate, but with limit...

BACKGROUND Applications of the power-to-gas principle for the handling of surplus renewable electricity have been proposed. The feasibility of using hydrogenotrophic methanogens as CH4 generating catalysts has been demonstrated. Laboratory and scale-up experiments have corroborated the benefits of the CO2 mitigation via biotechnological conversion of H2 and CO2 to CH4. A major bottleneck in the...

Thirty-five available feeds were fermented in vitro in order to investigate their soluble total organic carbon (TOCs) and methane (CH4) production rate. A fermentation reactor was designed to capture the CH4 gas emitted and to collect liquor from the reactor during in vitro fermentation. The results showed that CH4 production rate greatly varied among feeds with different ingredients. The lowes...

Baseline characterization of concentrations and isotopic values of dissolved natural gases is needed to identify contamination caused by the leakage of fugitive gases from oil and gas activities. Methods to collect and analyze baseline concentration-depth profiles of dissolved CH4 and C2 H6 and δ13 C-CH4 in shales and Quaternary clayey tills were assessed at two sites in the Williston Basin, Ca...

A room-temperature continuous-wave (CW) quantum cascade laser (QCL)-based methane (CH4) sensor operating in the mid-infrared near 8 μm was developed for continuous measurement of CH4 concentrations in ambient air. The well-isolated absorption line (7F2,4 ← 8F1,2) of the ν4 fundamental band of CH4 located at 1255.0004 cm(-1) was used for optical measurement of CH4 concentration by direct absorpt...

A method was developed to estimate the consumption of CH4 and the release of CO2 by gas flaring using VIIRS nighttime data. The results agreed with the field data collected at six stations in Bakken field, North Dakota, USA, within ±50%, as measured by mean relative errors and with a correlation coefficient of 0.75. This improved over the NOAA NightFire estimates, likely due to: (1) more string...

Absorption and emission lines originating from the 3 C H stretching manifold of gas-phase CH4 were discovered in the high-resolution (R 1⁄4 25;000) infrared L-band spectrum along the line of sight toward NGC 7538 IRS 9. These observations provide a diagnostic of the complex dynamics and chemistry in a massive star-forming region. The line shapes resemble P Cygni profiles with the absorption and...

The largest natural biological sink for the radiatively active trace gas methane (CH4) is bacteria in soils that consume CH4 as an energy and carbon source. This sink has been shown to be sensitive to nitrogen (N) inputs and alterations of soil physical conditions. Given this sensitivity, conversion of native ecosystems to urban, suburban, and exurban managed lawns thus has potential to affect ...