Scholars and Literati at the Saint Petersburg Academy of Sciences (1724–1800)

This note is a summary description of the set of scholars and literati who participated in the activities of the Saint Petersburg Academy of Sciences, from its inception in 1724 to the eve of the Industrial Revolution (1800)

Experimental and computational analysis of thermoelectric modules based on melt-mixed polypropylene composites

Copyright © 2023 The Author(s). Researchers are constantly looking for new materials that exploit the Seebeck phenomenon to convert heat into electrical energy using thermoelectric generators (TEGs). New lead-free thermoelectric materials are being investigated as part of the EU project InComEss, with one of the anticipated uses being converting wasted heat into electric energy. Such research aims to reduce the production costs as well as the environmental impact of current TEG modules which mostly employ bismuth for their construction. The use of polymers that, despite lower efficiency, achieve increasingly higher values of electrical conductivity and Seebeck coefficients at a low heat transfer coefficient is increasingly discussed in the literature. This article presents two thermoelectric generator (TEG) models based on data previously described in the literature. Two types of designs are presented: consisting of 4- and 49-leg pairs of p- and n-type composites based on polypropylene melt-mixed with single-walled carbon nanotubes. The models being developed using COMSOL Multiphysics software and validated based on measurements carried out in the laboratory. Based on the results of the analysis, conductive polymer composites employing insulating matrices can be considered as a promising material of the future for TEG modules.European Union’s Horizon 2020 Research and Innovation Programme for project InComEss under Grant Agreement Number 862597

Heavy metal Concentration in Belanger's Croaker Fish, Johnius belangerii from Petrochemical Waste Receiving Estuary in the Persian Gulf, Iran

Abstract. Musa Estuary is receives various type of discharges such as petrochemical, industrial and urban waste, it also is a habitat for Johnius belangerii. This study was carried out to determine heavy metal concentrations in J. belangerii. Fish samples were taken from 5 creeks and acid digested for their heavy metal contents. Results showed that the highest level of Cd, Co, Cu, Ni and Pb was 7.21, 1.08, 1.12, 2.72 and 4.57 in liver, 1.88, 1.04, 2.09, 9.43 and 6.83 in gill and 0.14, ND, 5.61, 2.43 and 3.78 in muscle respectively. The level of heavy metals in muscle was lower than WHO standard, however the level of metals in fish were decreased by the increase of distance from PETZON. It is suggested that biomonitoring of contaminants in this estuary could serve as a good estimate of environmental health

Investigation and computational modelling of variable teg leg geometries

Copyright: © 2021 by the authors. In this work, computational modelling and performance assessment of several different types of variable thermoelectric legs have been performed under steady-state conditions and the results reviewed. The study conducted has covered geometries, not previously analysed in the literature, such as Cone-leg and Diamond-leg, based on the corresponding thermoelectric generator leg shape structure. According to the findings, it has been demonstrated that the inclusion of a variable cross-section can have an impact on the efficiency of a thermoelectric generator. It has been concluded that the Diamond configuration generated a slightly larger voltage difference than the conventional Rectangular geometry. In addition, for two cases, Rectangular and Diamond configurations, the voltage generated by a TEG module consisting of 128 pairs of legs was analysed. As thermal stress analysis is an important factor in the selection of TEG leg geometries, it was observed based on simulations that the newly implemented Diamond-leg geometry encountered lower thermal stresses than the traditional Rectangular model, while the Cone-shape may fail structurally before the other TEG models. The proposed methodology, taking into account the results of the simulation carried out, provides guidance for the development of thermoelectric modules with different forms of variable leg geometry.European Union’s Horizon 2020 Research and Innovation Programme for project InComEss under Grant Agreement Number 862597

Experimental and computational thermoelectric generator for waste heat recovery for aeronautic application

Data availability: Data will be made available on request.This study is a comprehensive exploration of a polymer nanocomposite-based Thermoelectric Generator (TEG) developed within the European project InComEss, specifically designed for aeronautical applications. The focus lies on evaluating the TEG's performance under thermal conditions representative of various aircraft flight stages. The TEG module, consisting of four sections with 17 p-n strips each, is constructed from aerospace-grade polycarbonate, exhibiting dimensions of 50 * 1 * 0.3 mm. In the laboratory phase, the TEG's performance is systematically assessed through a series of experiments. Temperature gradients, ranging from -15°C to 55°C, emulate conditions experienced during ascending and descending flight stages. The results indicate promising outcomes, showcasing the potential viability of polymer-based TEGs for aeronautical applications. Specifically, temperature gradients of 40-70°C, representative of atmospheric conditions and wing leading edge skin conditions, are applied across four test trials. The model validation demonstrates creditable agreement between computational outcomes and experimental data. Insights gained from COMSOL Multiphysics simulations includes temperature distribution, electric potential, and flow dynamics. Simulations conducted under varied temperature ranges provide valuable insights into the TEG's performance variability. Key findings include temperature distribution profiles, electric potential outputs under open and closed-circuit conditions, and a detailed flow analysis within a controlled thermal environment. The validated computational model not only enhances understanding of the TEG's behaviour, but also establishes a foundation for optimizing design parameters to enhance thermoelectric efficiency. The error analysis underscores the model's reliability, exhibiting an average error of 5.68% between computational and experimental results, reinforcing its suitability for scientific investigations of this nature.This work has been receiving financial support from the European Union’s Horizon 2020 Research and Innovation Programme for project InComEss under Grant Agreement Number 862597

Photo-Catalytic Degradation of Methylene Blue by ZnO/SnO2 Nanocomposite

In this study, considering the importance of protecting the environment and preventing the pollution caused by industrial plants, a nanocomposite each component thereof is capable of removing the desired combination to solve this problem has been produced. To achieve this goal, ZnO/SnO2nanocomposite was synthesized using the co-precipitation method. The characterization of this nanocomposite was conducted by DLS, XRD, FTIR and SEM. The nanocomposite size was about 15nm. Several parameters such as the initial concentration of the wastewater, as well as the amount of catalyst and time were investigated. The reduction of the particle size due to an increase in the surface area of​​ the nanocomposite increased the amount of decolorization. For all the performed experiments, the dye removal rate was 100% and the difference was to do with the time of the complete removal of methylene blue. A decrease in the concentration of methylene blue in the range of the tested concentrations reduced the decolorization, and by increasing the amount of nanocomposite in the range of the tested values, a decline in decolorization was observed

Heavy metal concentration in sediment, benthic, benthopelagic, and pelagic fish species from Musa Estuary (Persian Gulf)

The concentration of Cd, Co, Cu, Ni, and Pb was measured in sediment and three fish species collected from Musa Estuary, Persian Gulf. The concentration order of heavy metals in sediment were Ni > Co > Cu > Pb > Cd >. Concentrations of the heavy metals in the fish were apparently different among the three species. The concentrations of Cd and Ni in fish were Johnius belangerii > Euryglossa orientalis > Liza abu, while the Co and Cu levels were L. abu > E. orientalis > J. belangerii and E. orientalis > L. abu > J. belangerii, respectively. Result of regression analysis showed that there were no significant relationships between metal concentration in fish tissues and sediment, except for Ni concentration in the J. belangerii liver. The concentrations of studied metals in fish muscle were below the permissible limits proposed by FAO, WHO, and EC

Spatial and seasonal variations of heavy metal concentration in sediment, Musa estuary (Persian Gulf)

849-857Total concentration of Cd, Co, Cu, Ni, Pb and Fe, as well as geo-accumulation indicator and Enrichment factor were determined in Musa estuary in winter and summer. A GBC flam atomic absorption spectrometer was applied to measure the heavy metals concentration. Jafari and Ghazale creeks were the most polluted creeks among the other creeks. Geoaccumulation indicator shows that Zangi creek is moderately polluted by Pb element in winter. Enrichment factor indicated that Co inJafari, Ahmadi and Zangi creeks have moderately enrichment in summer and winter while Pb in Zangi creek has significant enrichment in winter. Relationship amongst the metals demonstrated that Co-Pb, Fe-Cu and Fe-Pb in summer and Cd-Co, Co-Cu and Ni-Fe have significant correlations

N-Sulfenylsuccinimide/phthalimide: an alternative sulfenylating reagent in organic transformations

In the field of organosulfur chemistry, sulfenylating agents are an important key in C–S bond formation strategies. Among various organosulfur precursors, N-sulfenylsuccinimide/phthalimide derivatives have shown highly electrophilic reactivity for the asymmetric synthesis of many organic compounds. Hence, in this review article, we focus on the application of these alternative sulfenylating reagents in organic transformations