We report a prototype CO2 gas sensor based on a simple blackbody infrared source and a spectrally narrow quantum cascade detector (QCD). The detector absorption spectrum is centered at 2260 cm−1 (4.4 μm) and has a full width at half maximum of 200 cm−1 (25 meV). It covers strong absorption bands of two spectrally overlapping CO2 isotopomers, namely the P-branch of CO2 and the R-branch of CO2. A...

We employ transient absorption spectroscopy to record the absorption spectrum of photogenerated charge carriers in Cu2O. We have found that CO2 reduction in Cu2O is limited by fast electron-hole recombination. The deposition of RuOx nanoparticles on Cu2O results in a twofold increased yield of long-lived electrons, indicating partially reduced electron-hole recombination losses. This observatio...

Narrow channels located in the longwave IR CO2 absorption region between approximately 13.2 and 14.5 μm, the well known CO2 slicing channels, have been proven to be quite effective for the estimates of cloud heights and effective cloud amounts as well as atmospheric temperature profiles. The designs of some of the near-future multi-channel earth observing satellite sensors cannot accommodate th...

We examined the hypothesis that elevated CO2 concentration would increase NO3- absorption and assimilation using intact wheat canopies (Triticum aestivum cv. Veery 10). Nitrate consumption, the sum of plant absorption and nitrogen loss, was continuously monitored for 23 d following germination under two CO2 concentrations (360 and 1000 micromol mol-1 CO2) and two root zone NO3- concentrations (...

In this letter, we present a nanophotonic device consisting of plasmonic nanopatch array (NPA) with integrated metal-organic framework (MOF) for enhanced infrared absorption gas sensing. By designing a gold NPA on a sapphire substrate, we are able to achieve enhanced optical field that spatially overlaps with the MOF layer, which can adsorb carbon dioxide (CO2) with high capacity. Experimental ...

We report time-resolved photodissociation and geminate recombination dynamics of I2 2 in size-selected I2 Arn and I2 ~CO2!n cluster ions by using ultrafast pump–probe techniques at 790 nm in conjunction with a tandem time-of-flight mass spectrometer. The absorption recovery, which reflects the time scale for photodissociation followed by recombination and vibrational relaxation of I2 2 inside t...

We report on a lidar approach to measure atmospheric CO2 column concentration being developed as a candidate for NASA’s ASCENDS mission. It uses a pulsed dual-wavelength lidar measurement based on the integrated path differential absorption (IPDA) technique. We demonstrated the approach using the CO2 measurement from aircraft in July and August 2009 over various locations. The results show clea...

The absorption of carbon dioxide into aqueous ammonia solution using packed column was investigated. The volumetric overall mass transfer coefficients (KGav) for CO2 absorption into aqueous ammonia solutions were evaluated over ranges of main operating variables , that is, upto 16kPa partial pressure of CO2, 61-214 m 3 /(m 2 .h) gas flow rate, 0.753.06 m 3 /(m 2 .h) liquid flow rate, 2%16% ammo...

We have previously demonstrated a pulsed direct detection IPDA lidar to measure range and the column concentration of atmospheric CO2. The lidar measures the atmospheric backscatter profiles and samples the shape of the 1,572.33 nm CO2 absorption line. We participated in the ASCENDS science flights on the NASA DC-8 aircraft during August 2011 and report here lidar measurements made on four flig...