In this research, the combination of artificial neural network (ANN) modeling and smooth basis function minimization (SBFM) algorithm were applied to Open Path Fourier transform infrared spectroscopy (OP-FTIR) for monitoring volatile organic compounds' concentration distribution in the air. ANN was utilized to analyze the measured mixture spectra containing chloroform, methanol, and methylene chloride; Then, SBFM was used to reconstruct each component's concentration distribution. The peak concentration locations and maximum concentration for three components are reconstructed accurately. The methodology presented in this paper has significant importance in detecting leaking source spot and monitoring airborne VOCs transport in chemical industrial workplaces.

Cultivated strawberry (Fragaria × ananassa), a world-famous fruit, is subjected to rapid softening during ripening, resulting in a shorter shelf life and severe economic losses during storage and transportation. However, there is limited understanding of the molecular mechanism underlying differences in fruit firmness during ripening and postharvest among cultivated strawberries. Here, we explored this molecular mechanism by comparing three cultivated strawberries via firmness measurement, transcriptome analysis, quantitative real-time PCR, and correlation analysis, and revealed that FaEXP7, FaPG2, FaPLA, and Faβ-Gal4, as potential softening activators expressed before harvest to determine fruit with more softened texture and shorter shelf life, and the extremely high expression levels of FaCEL1-1 and FaCEL1-3 during ripening might be accelerators to intensify this situation. Additionally, both the enzyme activities of FaCEL and the expression pattern of FaCEL1-3 showed a significantly negative correlation with fruit firmness after harvest, suggesting that FaCEL1-3 might play a key role in promoting strawberry fruit softening not only during ripening but also postharvest. These results showed that the difference in fruit firmness and shelf life among cultivated strawberries was controlled by the temporal expression pattern of a legion of cell wall-associated genes during ripening and postharvest.

This research combined open path FTIR (OP-FTIR) technique and computed tomography (CT) to reconstruct air contaminant concentration distribution in a two-dimensional plane. Remote sensing FTIR instrument was used to scan radial beam geometry and obtain path integrated concentration (PIC) data of acetone gas in the measuring plane. Smooth basis function minimization (SBFM) algorithm was adopted to reconstruct gaseous concentration distribution. For the purpose of finding out the preferable number of Gaussians used in SBFM algorithm, single-Gaussian, double-Gaussian, and three-Gaussian models were used respectively. Experimental results showed that the reconstruction result of acetone concentration distribution by SBFM algorithm with double-Gaussian model agreed with real distribution more qualitatively and quantitatively than single-Gaussian and three-Gaussian. Also, it has been proved that simulated annealing algorithm used in the optimization process of SBFM reconstruction was feasible and effective. Although computed tomography and remote sensing FTIR technique (CT-RS-FTIR) is still at the laboratory study stage, with further improvement of SBFM algorithm and beam geometry, it promises to be used in air pollution monitoring widely.

A one-dimensional mapping technique coupled with Open-Path remote sensing FTIR was presented in this article. This technique was applied to one of the air toxic volatile organic compounds (VOCs)-toluene. The Path Integrated Concentrations (PICs) of toluene in different path lengths along one beam path were fitted by polynomial fitting method with degrees from 3 to 7. The 6th degree polynomial fitting showed the best fitting result. Moreover, the methods of reconstructing path concentration distribution along the beam path by applying a Gaussian model and the derivative of 6th degree polynomial fitting function were established in this article. The reconstructed concentrations of toluene along the beam path by the two methods were experimentally close. Results showed that the concentration peaks were at 1.05 and 2.40 m from the instrument by applying the Gaussian model with the maximum concentration of 0.85 and 3.19 ppm, and at 0.99 and 2.49 m from the instrument with the maximum concentration of 0.78 and 2.80 ppm by applying the 6th polynomial fitting function. It was obvious that the reconstruction results by these two methods were very close. This approach could be appreciated for its fast calculation, exact peak location orientation and concentration flow tendency mapping. In can be concluded that this method can provide the path concentration distributions of much more releasing gases in a briefly and intuitionistic way. The remote sensing FTIR coupled with these mathematical reconstruction techniques can be applied to the real world environmental and industrial hygiene monitoring, thus works as an alert system for the VOCs pollution.