The Impact of the Improved Search Object Detection on the SAR Action Success Probability in Maritime Transport.

This paper presents the investigations on the improvement of search object detection during search and rescue (SAR) action at sea using thermal imaging and radar sensors. The introduction of new materials in the construction of lifesaving appliances increasing their detectability has been studied for the selected example of a pneumatic life raft. The research was based on laboratory tests and open sea trials. The presented experimental investigations on the new materials that can be used for pneumatic life raft construction showed the enhancement of its thermal and radar signatures, which directly affect life raft detectability and influence reliability of SAR action and probability of success (POS). The improved detectability of a life raft related to the time to survive of a person in the water (PIW) allowed to present the modified search pattern for both PIW and life raft, significantly increasing POS.

Inorganic-organic modular silicon and dye-sensitized solar cells and predicted role of artificial intelligence towards efficient and stable solar chargers based on supercapacitors.

Appropriate and rational management of the energy produced by renewable energy sources is one of the most urgent challenges for the global energy sector. This paper is devoted to the systematic experimental and theoretical studies of a modular solar charger based on silicon and dye-sensitized solar cells as an energy source, and supercapacitor as an energy bank. Using the MathCAD program, I-V characteristics were plotted for both a single cell and a photovoltaic module based on various series-to-parallel connections. To assess the surface quality of the modules, additional tests using a thermal imaging camera were carried out as well. The charging characteristics of the supercapacitor (two series-connected cells with a capacity of 300 F), were determined depending on the parameters of the photovoltaic module as well as considering the influence of the voltage balancing system and control system. The charge, discharge, and recharge characteristics were carefully analyzed to optimize the operating conditions, i.e. the number of photovoltaic cells. To evaluate the stability of parameters with operation time, and their temperature dependence (17-65 °C), solar modules were tested for ten days under Central European weather conditions. Importantly, a comparative analysis of solar chargers based on different configurations of photovoltaic cells showed an increase in electrical parameters for the proposed modular inorganic-organic concept compared to dye-sensitized solar cells produced alone on a rigid substrate. Finally, preliminary assumptions (requirements) were developed regarding the electrical and optical parameters for new dye-sensitized solar cells that could be used in the innovative solar charger instead of silicon cells along with a predicted role of artificial intelligence (AI) in these devices.

Air-Stable and Eco-Friendly Symmetrical Imine with Thiadiazole Moieties in Neutral and Protonated form for Perovskite Photovoltaics.

This paper proposes molecular and supramolecular concepts for potential application in perovskite solar cells. New air-stable symmetrical imine, with thiadiazole moieties PPL2: (5E,6E)-N2,N5-bis(4-(diphenylamino)benzylidene)-1,3,4-thiadiazole-2,5-diamine), as a hole-transporting material was synthesised in a single-step reaction, starting with commercially available and relatively inexpensive reagents, resulting in a reduction in the cost of the final product compared to Spiro-OMeTAD. Moreover, camphorsulfonic acid (CSA) in both enantiomeric forms was used to change the HOMO-LUMO levels and electric properties of the investigated imine-forming complexes. Electric, optical, thermal, and structural studies of the imine and its complexes with CSA were carried out to characterise the new material. Imine and imine/CSA complexes were also characterised in depth by the proton Nuclear Magnetic Resonance 1H NMR method. The position of nitrogen in the thidiazole ring influences the basicity of donor centres, which results in protonation in the imine bond. Simple devices of ITO/imine (with or without CSA(-) or CSA(+))/Ag/ITO architecture were constructed, and a thermographic camera was used to find the defects in the created devices. Electric behaviour was also studied to demonstrate conductivity properties under the forward current. Finally, the electrical properties of imine and its protonated form with CSA were compared with Spiro-OMeTAD. In general, the analysis of thermal images showed a very similar response of the samples to the applied potential in terms of the homogeneity of the formed organic layer. The TGA analysis showed that the investigated imine exhibits good thermal stability in air and argon atmospheres.

Gaussian Model of Anti-Radar Properties for Coatings Based on Carbonyl Iron Powder.

The article presents the Gaussian model of the electromagnetic radiation attenuation properties of two resin systems containing 75% or 80% of a carbonyl iron load as an absorber in the 4-18 GHz range. For the attenuation values obtained in the laboratory, mathematical fitting was performed in the range of 4-40 GHz to visualize the full curve characteristics. The simulated curves fitted up to a 0.998 R2 value of the experimental results. The in depth analysis of the simulated spectra allowed a thorough evaluation of the influence of the type of resin, absorber load, and layer thickness on reflection loss parameters such as the maximum attenuation, peak position, half-height width, and base slope of the peak. The simulated results were convergent with the literature findings, allowing a much deeper analysis. This confirmed that the suggested Gaussian model could provide additional information, useful in terms of comparative analyses of datasets.

Siloxane resins as hydrophobic self-cleaning layers for silicon and dye-sensitized solar cells: material and application aspects.

The aim of this study has been to examine in depth three siloxane resins (R1-R3) and two silanes (S1-S2) as hydrophobic self-cleaning layers for silicon and dye-sensitized solar cells. Herein, we focused on creating an active self-cleaning surface system using a combination of material and technical aspects. Siloxane resins were obtained via the hydrolytic polycondensation of methyltrimethoxysilane (R1) or the hydrolytic co-polycondensation of methyltrimethoxysilane, isobutyltrimethoxysilane and 3-methacroiloxypropyltrimethoxysilane (R2) or methyltrimethoxysilane n-octyltriethoxysilane and 3-methacroiloxypropyltrimethoxysilane (R3) under alkaline conditions using tetrahydrofuran. All layers under study did not significantly affect the original optical properties of the glass support, confirming that all these compounds can be used as protective layers on glass surfaces. The hydrophobic nature of formed layers was confirmed by static water contact angle measurements for hexane- and/or dibutyl ether-based starting solutions at various concentrations. The structural defects in created layers were studied via atomic force microscopy and thermal imaging, revealing RMS roughness (R q) values in the range of 0.76-5.25 nm, which varied for different materials. The current-voltage curves of different hydrophobic coatings showed conductive behaviour, demonstrating that principally non-conductive coatings mixed with silver conductive paste showed a certain level of conductivity. This finding suggests that the hydrophobic coating resembles a porous structure, enabling the formation of electrically conductive pathways. Finally, the influence of the presence of a coating layer on silicon and dye-sensitized solar cells was studied, and no negative effect on their photovoltaic parameters was observed after the durability test.

Crystal Structure Determination of 4-[(Di-p-tolyl-amino)-benzylidene]-(5-pyridin-4-yl-[1,3,4]thiadiazol-2-yl)-imine along with Selected Properties of Imine in Neutral and Protonated Form with Camforosulphonic Acid: Theoretical and Experimental Studies.

The crystal structure was determined for the first time for 4-[(di-p-tolyl-amino)benzylidene]-(5-pyridin-4-yl-[1,3,4]thiadiazol-2-yl)-imine (trans-PPL9) by X-ray diffraction. The imine crystallized in the monoclinic P21/n space group with a = 18.9567(7) Å, b = 6.18597(17) Å, c = 22.5897(7) Å, and ß = 114.009(4)°. Intermolecular interactions in the PPL9 crystal were only weak C-H⋯N hydrogen bonds investigated using the Hirshfeld surface. The electronic and geometric structure of the imine were investigated by the density functional theory and the time-dependent density-functional theory. The properties of the imine in neutral and protonated form with camforosulphonic acid (CSA) were investigated using cyclic voltammetry, UV-vis and 1H NMR spectroscopy. Theoretical and experimental studies showed that for the 1:1 molar ratio the protonation occured on nitrogen in pyridine in the PPL9 structure, as an effect of Brönsted acid-base interactions. Thermographic camera was used to defined defects in constructed simple devices with ITO/PPL9 (or PPL9:CSA)/Ag/ITO architecture. In conclusion, a thermally stable imine was synthesized in crystalline form and by CSA doping, a modification of absorption spectra together with reduction of overheating process was observed, suggesting its potential application in optoelectronics.

PEDOT:PSS in Water and Toluene for Organic Devices-Technical Approach.

Poly(3,4-ethylenedioxythiophene:poly(styrenesulfonate) (PEDOT:PSS) water and toluene solutions were investigated in detail, taking into consideration their stability, wettability, transparency, and electrochemical properties, along with change polarity caused by dopant. As dopant, methanol, ethanol, and isopropanol were used with different dipole moments (1.70, 1.69, and 1.66 D) and dielectric constants (33.0, 24.5, and 18.0). Three techniques, i.e., spin coating, doctor blade coating, and spray coating, were employed to created PEDOT:PSS layers on glass, glass/indium tin oxide (ITO), and glass/fluorine-doped tin oxide (FTO) substrates with optimized technical parameters for each used equipment. All used PEDOT:PSS water and toluene solutions demonstrated good wetting properties with angles below 30° for all used surfaces. Values of the energy bandgap (Eg) of PEDOT:PSS investigated by cyclic voltammetry (CV) in solution showed increase energy Eg along with addition of alcohol to the mixture, and they were found in the range of 1.20 eV to 2.85 eV. The opposite tendency was found for the Eg value of the PEDOT:PSS layer created from water solution. The storage effect on PEDOT:PSS layers detected by CV affected only the lowest unoccupied molecular orbital (LUMO) level, thereby causing changes in the energy bandgap. Finally, simple devices were constructed and investigated by infrared (IR) thermographic camera to investigate the surface defects on the created PEDOT:PSS layers. Our study showed that a more stable PEDOT:PSS layer without pin-holes and defects can be obtained from water and toluene solutions with isopropanol via the spin coating technique with an optimal speed of 3000 rpm and time of 90 s.

Research of Binary and Ternary Composites Based on Selected Aliphatic or Aliphatic-Aromatic Polymers, 5CB or SWCN Toward Biodegradable Electrodes.

The main goal of this paper was to study the optical, electrical, and thermal properties of hybrid composites based on biodegradable polymers (L,D-poly(lactic acid), polycaprolactone or Ecoflex®), single walled carbon nanotubes (SWCN), and 4'-pentyl-4-biphenylcarbonitrile (5CB). The biodegradable polymers' binary and ternary compositions were analyzed in detail by ultraviolet and visible (UV-Vis) spectroscopy taking into consideration their chemical structure and interactions with 5CB and SWCN. Differential scanning calorimetry (DSC) studies of the created hybrid layers showed thermal stability and changes in glass transition temperature and melting point in comparison to neat polymers, depending on the chemical structure of the polymer used and the type of composition. Morphology of the created layers were investigated by atomic force and polarizing microscopy. The static contact angle measurements of a water drop showed that all of the neat polymer layers were hydrophobic with angle values ranging from 108° to 115°. In addition, in the case of the Ecoflex layers, both with and without additives, a rapid sorption of the deposited water drop was observed. Finally, a simple device with poly(ethylene terephthalate) (PET)/indium tin oxide (ITO)/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/poly [[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl ]] (PTB7) : [6,6]-phenyl-C71-butyric acid methyl ester (PC70BM)/Ag/biodegradable polymer:SWCN architecture was constructed and tested using an infrared (IR) thermographic camera to investigate the surface defects on the created hybrid layers. Increasing the SWCN admixture from 0.01 to 0.5% significantly improved the conductivity only in the case of L,D-poly(lactic acid):SWCN (10:0.5), for which above 5 V, a current with a resistance of 3030.7 Ω could be measured. In order to use the created layers as flexible electrodes, the first experiments were carried out with an admixture of SWCN and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) as conductive compounds.

A comprehensive optical and electrical study of unsymmetrical imine with four thiophene rings and their binary and ternary compositions with PTB7 and PC70BM towards organic photovoltaics.

A new unsymmetrical imine with four thiophene rings was synthesized in a one-step reaction, starting from the commercially available and relatively inexpensive reagents. The obtained imine in the form of thin films exhibited photoluminescence properties in the 1.8-2.4 eV energy range and a photoluminescence lifetime of about 0.3 ns. The HOMO and LUMO levels of the imine determined by cyclic voltammetry were at about -5.19 eV and -3.05 eV, respectively. The density functional theory was applied to calculate the geometric and electronic structure of the imine. The UV-Vis spectra showed that the absorption range of the imine overlaps with that of PC70BM, and the absorption peak at the maximum of the imine at 424 nm is located between the two maxima at 404 nm and 461 nm of the fullerene derivative. The electron acceptor and donor activity of the imine was tested in the solar cell architecture: glass/ITO/PEDOT:PSS/active layer/In/Al. The best photovoltaic parameters, with very good reproducibility for each 8 pixels in the cell, were found for the active layer based on ternary mixture PTB7:PC70BM:imine at a weight ratio 8 : 13 : 1, with the power conversion efficiency of about 4%. The external quantum efficiency of devices with the imine was found to be about 40% at 3.3 eV. The thermal imaging together with the recorded current response at increasing potential showed that the presence of imine in the composition has a beneficial impact in terms of current flow stability at temperatures above 200 °C, compared to two component layers with the same imine as an additive.

Selected Electrochemical Properties of 4,4'-((1E,1'E)-((1,2,4-Thiadiazole-3,5-diyl)bis(azaneylylidene))bis(methaneylylidene))bis(N,N-di-p-tolylaniline) towards Perovskite Solar Cells with 14.4% Efficiency.

Planar perovskite solar cells were fabricated on F-doped SnO2 (FTO) coated glass substrates, with 4,4'-((1E,1'E)-((1,2,4-thiadiazole-3,5-diyl)bis(azaneylylidene))bis(methaneylylidene))bis(N,N-di-p-tolylaniline) (bTAThDaz) as hole transport material. This imine was synthesized in one step reaction, starting from commercially available and relatively inexpensive reagents. Electrochemical, optical, electrical, thermal and structural studies including thermal images and current-voltage measurements of the full solar cell devices characterize the imine in details. HOMO-LUMO of bTAThDaz were investigated by cyclic voltammetry (CV) and energy-resolved electrochemical impedance spectroscopy (ER-EIS) and were found at -5.19 eV and -2.52 eV (CV) and at -5.5 eV and -2.3 eV (ER-EIS). The imine exhibited 5% weight loss at 156 °C. The electrical behavior and photovoltaic performance of the perovskite solar cell was examined for FTO/TiO2/perovskite/bTAThDaz/Ag device architecture. Constructed devices exhibited good time and air stability together with quite small effect of hysteresis. The observed solar conversion efficiency was 14.4%.

UV-Vis Absorption Properties of New Aromatic Imines and Their Compositions with Poly({4,8-bis[(2-Ethylhexyl)oxy]Benzo[1,2-b:4,5-b']Dithiophene-2,6-diyl}{3-Fluoro-2-[(2-Ethylhexyl)Carbonyl]Thieno[3,4-b]Thiophenediyl}).

In this paper, four new aromatic imines containing at least one thiazole-based heterocycle were analyzed in detail by UV-Vis spectroscopy, taking into consideration their chemical structures and interactions with PTB7, a known polymeric electron donor widely used in bulk heterojunction organic solar cells. It is demonstrated that the absorption spectra of the investigated active compositions can be modified not only by changing the chemical structure of imine, but also via formulations with PTB7. For all investigated imines and PTB7:imine compositions, calibration curves were obtained in order to find the optimum concentration in the composition with PTB7 for expansion and optimization of absorption spectra. All imines and PTB7:imine compositions were investigated in 1,2-dichlorobenzene by UV-Vis spectroscopy in various concentrations, monitoring the changes in the π-π* and n-π* transitions. With increasing imine concentrations, we did not observe changes in absorption maxima, while with increasing imine concentrations, a hypochromic effect was observed. Finally, we could conclude that all investigated compositions exhibited wide absorptions of up to 800 nm and isosbestic points in the range of 440-540 nm, confirming changes in the macromolecular organization of the tested compounds. The theoretical calculations of their vibration spectra (FTIR) and LUMO-HOMO levels by Density Functional Theory (DFT) methods are also provided. Finally, IR thermal images were measured for organic devices based on imines and the imine:PTB7 composite.