Spectral-luminescent properties of bromcresol purple

The influence of the solvent on the spectral-luminescent properties of bromcresol purple (BCP) has been studied. The spectral characteristics of BCP: half-width, Stokes shift, molar absorption coefficient, intrinsic excited state lifetime, and oscillator strength are determined. Using the Lippert equation, the dependence of the Stokes shift of BCP on the orientational polarizability of the solvent has been constructed. An analysis of the experimental data showed that the position of the maximum of the BCP absorption band in the region of 350–480 nm correlates with the acceptor number of the solvent: with a decrease in the acceptor number, the band maximum shifts toward shorter wavelengths (water ethanol toluene acetone). The lowest absorption capacity of BCP was registered in toluene. Using the Lippert–Mataga equation, the change in the dipole moment in polar protic solvents (16.2 D) upon excitation was determined, which is higher than in aprotic solvents (10.4 D) due to the formation of H-bonds

Phototransformation of bisphenol a in water in the presence of materials based on ultrafine polypropylene fibers

The effect of UV radiation on the efficiency of bisphenol A (BPA) phototransformation in water in the presence of polypropylene nonwoven material based on ultrafine fibers has been studied. The absorption and fluorescence spectra of the investigated substance with fibers of different properties have been obtained. After excitation with an excilamp, the main photoproduct - BPA - fluoresces in the region of similar to 408 nm. With an increase in the irradiation time from 0 to 10 min, the fluorescence intensity of this photoproduct increases. The absorption and fluorescence spectra of cyclohexane containing compounds desorbed from the fiber surface indicate the adsorption of the photoproduct on its surface during UV irradiation

Photodegradation of bisphenol A in the presence of superfine microfiber polypropylene

The effect of UV radiation on the efficiency phototransformation BPA in water in the presence of polypropylene superfine microfibers. The absorption and fluorescence spectra of the investigated substance with three types of PPM of various properties were obtained. After excitation with an excilamp, the main photoproduct BPA fluoresces in the region of 405÷410 nm. With an increase in the irradiation time from 0 to 10 minutes, an increase in the fluorescence intensity of this BPA photoproduct was recorded. This indicates that in the course of irradiation, effective photodegradation of the initial toxicant occurs and a photoproduct is formed. In the course of irradiation, the degradation of the resulting photoproducts occurs, which is associated with their adsorption on the surface of the PPM

Causal chains, policy trade offs and sustainability: Analysing land (mis)use in seven countries in the South

The need to enhance sustainable development of land use is more urgent than ever; specifically in developing countries where poverty and land degradation are often interlinked. To promote a common understanding of land use problems by experts, stakeholders and decision makers, it is essential to understand the system characteristics, including the complex feedbacks between drivers and impacts. To enhance sustainable development, appropriate policies need to be identified. In this paper, we analysed and compared seven case studies in Kenya, Mali, Tunisia, China, India, Indonesia and Brazil, representing different biophysical and socio-economic conditions and challenges. We analysed Driver Pressure State Impact Response (DPSIR) story lines of the land use problems, policy priorities and value trade-offs as identified by stakeholders and experts in National Policy Forums. Important drivers of land use change impacting main land use problems among the case studies were economic growth, technological development, immigration and agricultural intensification, in addition to existing policies. Of the latter the most important were related to domestic support through various forms of subsidies or access to credit, land tenure polices and liberalization policies. In the policy prioritization, the value trade-offs made by the National Policy Forums emphasize the environment rather than increased economic production. It is recognized that the environment needs to be improved to maintain and improve economic production in the long term, both in agriculture and in other sectors