The effect of various cleaning methods on coating morphology and their effectiveness in removing organic contaminants has been studied in this research. Bioactive coatings containing titanium oxides ...and hydroxyapatite (HAP) were obtained through plasma electrolytic oxidation in aqueous electrolytes and molten salts. The cleaning procedure for the coated surface was performed using autoclave (A), ultraviolet light (UV), radio frequency (RF), air plasma (P), and UV-ozone cleaner (O). The samples were characterized using scanning electron microscopy (SEM) with an EDS detector, X-ray photoelectron spectroscopy (XPS), X-ray phase analysis (XRD), and contact angle (CA) measurements. The conducted studies revealed that the samples obtained from molten salt exhibited a finer crystalline structure morphology (275 nm) compared to those obtained from aqueous electrolytes (350 nm). After applying surface cleaning methods, the carbon content decreased from 5.21 at.% to 0.11 at.% (XPS), which directly corresponds to a reduction in organic contaminations and a decrease in the contact angle as follows: A > UV > P > O. This holds true for both coatings obtained in molten salt (25.3° > 19.5° > 10.5° > 7.5°) and coatings obtained in aqueous electrolytes (35.2° > 28.3° > 26.1° > 16.6°). The most effective and moderate cleaning method is ozone treatment.
The exceptional property of plasmonic materials to localize light into sub-wavelength regimes has significant importance in various applications, especially in photovoltaics. In this study, we report ...the localized surface plasmon-enhanced perovskite solar cell (PSC) performance of plasmonic gold nanoparticles (AuNPs) embedded into a titanium oxide (TiO2) microdot array (MDA), which was deposited using the inkjet printing technique. The X-ray (XRD) analysis of MAPI (methyl ammonium lead iodide) perovskite films deposited on glass substrates with and without MDA revealed no destructive effect of MDA on the perovskite structure. Moreover, a 12% increase in the crystallite size of perovskite with MDA was registered. Scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HR-TEM) techniques revealed the morphology of the TiO2_MDA and TiO2-AuNPs_MDA. The finite-difference time-domain (FDTD) simulation was employed to evaluate the absorption cross-sections and local field enhancement of AuNPs in the TiO2 and TiO2/MAPI surrounding media. Reflectance UV-Vis spectra of the samples comprising glass/TiO2 ETL/TiO2_MDA (ETL—an electron transport layer) with and without AuNPs in TiO2_MDA were studied, and the band gap (Eg) values of MAPI have been calculated using the Kubelka–Munk equation. The MDA introduction did not influence the band gap value, which remained at ~1.6 eV for all the samples. The photovoltaic performance of the fabricated PSC with and without MDA and the corresponding key parameters of the solar cells have also been studied and discussed in detail. The findings indicated a significant power conversion efficiency improvement of over 47% in the PSCs with the introduction of the TiO2-AuNPs_MDA on the ETL/MAPI interface compared to the reference device. Our study demonstrates the significant enhancement achieved in halide PSC by utilizing AuNPs within a TiO2_MDA. This approach holds great promise for advancing the efficiency and performance of photovoltaic devices.
The main purpose of the study is to develop a method based on the modified ant algorithm and demonstrate the applicability of its use for building of optimal cargo delivery routes, taking into ...account the real (non-stationary) dynamics of highdensity traffic on the urban road network in megacities. Within the framework of the proposed method the simulation of building optimal routes, by the example of Kiev, was carried out. The results of study indicate the possibility of using the method for the solution to the problems of efficient management of the freight transportation routing process in the conditions of real dynamics of traffic flows (dense traffic, traffic jam, emergency situations, etc.).
Displacement of floating polymer (polyolefin) rafts by steady magnetic field is reported. The effect is due to the interplay of gravity deforming the water/vapor interface, contact angle hysteresis ...and diamagnetic properties of the liquid support. Magnetic field (ca.0.06T) deformed the water/vapor interface and impacted the interfacial apparent contact angle. This deformation gave rise to the propulsion force, displacing the polymer raft. The velocity of displacement of center of mass of rafts vcm≅0.015ms was registered. The effect is related to the contact angle hysteresis affected by the magnetic field, enabling the change in the apparent interfacial contact angle. The semi-quantitative model of the process is suggested.
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•Displacement of floating polymer (polyolefin) rafts by steady magnetic field is reported.•Magnetic field deformed the water/vapor interface and impacted the interfacial contact angle.•The effect is due to the interplay of gravity, contact angle hysteresis and diamagnetic properties of the water.•The velocity of displacement of center of mass of rafts vcm≅0.015ms was registered.
A method for optimizing the route based on a modified ant algorithm is proposed, taking into account the unsteady dynamics of traffic flows in the urban road network. Within the framework of the ...method, simulation of the building of optimal routes was carried out using the example of Kyiv. It is shown the possibility of using the method for solving problems of effective control over the process of routing freight traffic in conditions of actual dynamics of traffic flows (synchronized traffic, wide moving jam, congestion, emergency situations, etc.)
Halide perovskites-based solar cells are drawing significant attention due to their high efficiency, versatility, and affordable processing. Hence, halide perovskite solar cells have great potential ...to be commercialized. However, the halide perovskites (HPs) are not stable in an ambient environment. Thus, the instability of the perovskite is an essential issue that needs to be addressed to allow its rapid commercialization. In this work, WS
nanoparticles (NPs) are successfully implemented on methylammonium lead iodide (MAPbI
) based halide perovskite solar cells. The main role of the WS
NPs in the halide perovskite solar cells is as stabilizing agent. Here the WS
NPs act as heat dissipater and charge transfer channels, thus allowing an effective charge separation. The electron extraction by the WS
NPs from the adjacent MAPbI
is efficient and results in a higher current density. In addition, the structural analysis of the MAPbI
films indicates that the WS
NPs act as nucleation sites, thus promoting the formation of larger grains of MAPbI
. Remarkably, the absorption and shelf life of the MAPbI
layers have increased by 1.7 and 4.5-fold, respectively. Our results demonstrate a significant improvement in stability and solar cell characteristics. This paves the way for the long-term stabilization of HPs solar cells by the implementation of WS
NPs.
Friction forces acting on rotators may promote their alignment and therefore eliminate degrees of freedom in their movement. The alignment of rotators by friction force was shown by experiments ...performed with different spinners, demonstrating how friction generates negentropy in a system of rotators. A gas of rigid rotators influenced by friction force is considered. The orientational negentropy generated by a friction force was estimated with the Sackur-Tetrode equation. The minimal change in total entropy of a system of rotators, corresponding to their eventual alignment, decreases with temperature. The reported effect may be of primary importance for the phase equilibrium and motion of ubiquitous colloidal and granular systems.
The commercialization of efficient and durable solid oxide fuel cells is hugely hindered due to the expensive and complex fabrication process. In this regard, the additive manufacturing technique, ...i.e., three-dimensional printing (3-D printing), has gained tremendous attention because of its ability to fabricate tunable functional ceramic layers with cost-effectiveness and mass customization. Therefore, in this work, the anode (NiO-ScSZ) and cathode (LSM) of the large-area SOFC (5 × 5 cm2) are printed using a direct-ink-writing (DIW) printer. The anode-functional and electrolyte layers are coated by spray and spin coating. The viscosity of the optimized anode and cathode inks are 5.85 Pa s and 0.97 Pa s, respectively. The electrochemical impedance and the performance of 3D-SOFC are investigated by supplying hydrogen and air. The maximum power density of the cell is 368 mW cm−2 at 800 °C. However, by inserting a hybrid scandia stabilized zirconia layer by spraying followed by magnetron sputtering onto the AFL, the electrochemical performance of the cell is significantly (21%) enhanced; the peak power density is 442 mW cm−2, and the corresponding polarization resistance is 0.267 Ω cm2 at 800 °C. Furthermore, the long-term cell test under galvanostatic mode (j = 0.5 A cm−2) at 700 °C for 100 h and thermal cycling between 400 and 700 °C concludes that the 3D-SOFC exhibits exceptional stability with a voltage loss of 0.845% h−1 and thermomechanical durability.
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•Highly efficient and durable SOFC (5 × 5 cm2) is fabricated by a DIW printer.•The peak power of the 3D-SOFC is 368 mW cm−2 at 800 °C.•Inserting a hybrid-ScSZ layer further increases the cell power by 21%.•The 3D-printed SOFC experiences a voltage loss of 0.854%/h after 100 h.•The DIW-printed electrodes show no delamination upon multiple thermal cycling.
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