Real-time imaging of CO in vehicle exhaust was demonstrated using a gas correlation spectrometry based mid-infrared camera for the first time. The novel gas-correlation imaging technique is used to eliminate the spectral interferences from background radiation and other major combustion products, and reduce the influences of the optical jitter and temperature variations, thereby identifying and quantifying the gas. We take several spectral factors into account for the instrument design, concentration calibration and data evaluation, including atmospheric transmission, radiation interference, as well as the spectral response of infrared camera, filter and gas cell. A calibration method based on the molecular spectroscopy and radiative transfer equation is developed to identify the numerical relationship between the CO concentration × length and the measured image intensity. Two-dimensional CO distribution of vehicle exhaust with a time resolution of 50 Hz and detection limit of 20 ppm × meter is achieved when the distance between optical equipment and engine nozzle is 3 m. The gas correlation spectrometry based mid-infrared camera shows a great potential as a future technique to monitor vehicle pollution emissions quantitatively and visually.
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http://dx.doi.org/10.1364/OE.26.008239 | DOI Listing |
PDA J Pharm Sci Technol
December 2024
Nelson Labs, Romeinsestraat 12, 3001 Heverlee, Belgium.
Leachables in drug products and from medical devices can adversely affect patient health and thus must be identified and quantified. Accurate and protective quantitation in target analysis for leachables (and extractables as potential leachables) is accomplished via compound-specific calibration curves. Quantification in non-targeted analysis (NTA) is complicated by the variable relative response factors (RRFs) among and between individual leachables and the circumstance that the leachables are not known until the NTA is completed.
View Article and Find Full Text PDFJ Environ Manage
December 2024
College of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao, 266520, China.
The disposal of municipal solid waste (MSW) is a significant source of greenhouse gas (GHG) emissions. As incineration becomes the primary method of MSW disposal in China, MSW incineration (MSWI) plants are expected to play a crucial role in mitigating GHG emissions in the waste sector. This study estimated the quarterly GHG emissions from two representative MSWI plants in Qingdao using a life-cycle assessment (LCA) approach.
View Article and Find Full Text PDFRev Sci Instrum
December 2024
School of Mechatronic Engineering, Southwest Petroleum University, Chendu 610500, China.
The early fault characteristics of rolling bearings are weak, especially in a strong noise environment, which are more difficult to extract; therefore, a method based on wavelet packet decomposition, multi-verse optimizer, and maximum correlated kurtosis deconvolution for weak fault feature extraction of rolling bearings is proposed. First, the original vibration signal is decomposed using wavelet packet decomposition, followed by proposing a signal reconstruction method combining the Pearson correlation coefficient and energy ratio to effectively remove noise from the original signal. Second, the parameters L and M of Maximum Correlated Kurtosis Deconvolution (MCKD) are optimized using the multi-verse optimizer algorithm to obtain optimal filter settings.
View Article and Find Full Text PDFInorg Chem
December 2024
Department of Geological Sciences, Pusan National University, Busan 46241, Korea.
Synthetic mordenite is widely used as a molecular sieve, adsorbent, and catalyst. To enhance these functionalities, it is crucial to understand the ion-exchange properties and cation-exchange sites of the zeolite. In this study, we analyzed the structural changes in fully Cs-, Sr-, Cd-, and Pb-exchanged mordenite by using synchrotron X-ray powder diffraction under ambient conditions.
View Article and Find Full Text PDFNitrous oxide (NO) is generally used in the medical and food industries. However, it is sometimes illegally misused by young adults as a recreational drug. In either of these uses, functional vitamin B12 deficiency results in neurological implications, such as peripheral neuropathy and subacute combined degeneration (SACD).
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