Treatment of Light-Induced Degradation for Solar Cells in a p-PERC Solar Module via Induction Heating

In the photovoltaic industry, there is great interest in increasing the power output of solar cells to achieve grid parity and to promote the widespread use of solar cells. However, despite many developments, a phenomenon called light-induced degradation causes the efficiency of solar cells to deteriorate over time. This study proposes a treatment that can be applied to cells within solar modules. It uses a half-bridge resonance circuit to induce a magnetic field and selectively heat Al electrodes in the solar cells. The electrical state of a solar module was measured in real time as it was being heated, and the results were combined with a kinetics simulation using a cyclic reaction. As the temperature of the solar module increased, the time taken to reach the saturation point and the recovery time decreased. Moreover, the value of the saturation point increased. The light-induced degradation activation energy was similar to results in the existing literature, suggesting that the kinetic model was valid and applicable even when 72 cells were connected in series. This demonstrates that an entire solar module can be treated when the cells are connected in series, and in future multiple modules, could be connected in series during treatment.

An Evaluation of Optical Absorbance Kinetics for the Detection of Micro-Porosity in Molecularly Doped Polymer Thin-Films

The use of optical absorbance kinetics to identify micro-porous regions in doped polymer films is evaluated. Data are presented for a series of hydrazone doped polymer films which are found to optically bleach upon exposure to an ultra violet (UV) radiation source. The UV absorbance kinetics are found to exhibit distinctive characteristics for the various polymers studied, with changes in film absorbance occurring either in a fast (<103 s) or slow (>104 s) timescale. An interpretation of these distinctive timescales based upon a cellular-automata model of the absorbance kinetics suggests that the underlying photo-oxidation of the hydrazone is highly sensitive to underlying micro-porosity in the films which controls the necessary supply of absorbed oxygen for photo-cyclic reaction.

The phenomenon of conservative-perturbed equilibrium in conditions different reactors

Finding the optimal mode is a conceptual problem. The most important indicator that reflects the perfection of a chemical reactor is the intensity of the process in it. The phenomenon of conservatively perturbed-equilibrium (CPE) in the conditions of different types of reactors (in acyclic and cyclic systems) was studied: the ideal displacement reactor ("steady-state plug flow reactor, PFR") and the ideal mixing reactor ("steady-state continuous stirred tank reactor, CSTR"). For the acyclic reaction, the time of extremum onset was less in CSTR by ≈2.1%, but the concentration of substance B in the extremum in PFR was greater by ≈17.2% than in CSTR. For the cyclic reaction, the time of extremum onset was less in CSTR by ≈5.6%, but the concentration of substance B in the extremum in PFR was greater by ≈11.6% than in CSTR. For the acyclic and cyclic reaction in PFR, the time of occurrence of the extremum of the cyclic reaction was lower by ≈44.2% than in the acyclic, but the concentration of substance B in the extremum of the acyclic reaction was greater by ≈24.8% than in the cyclic reaction. For the acyclic and cyclic reaction in CSTR, the time of occurrence of the extremum of the cyclic reaction was lower by ≈46.2% than in the acyclic, but the concentration of substance B in the extremum in the acyclic reaction was greater by ≈18.9% than in the cyclic reaction. The cyclic system showed a shorter time for the onset of the extremum, but the acyclic reaction system showed a higher concentration of substance B at the extremum in PFR and CSTR. Although the time of extremum onset was the lowest in CSTR in the cyclic system, the concentration of substance B in the extremum was highest in the PFR in the acyclic system. Therefore (from our systems and reactors) the acyclic system in PFR shows the best characteristics. The extremum in transient modes is always observed for acyclic and cyclic complex reactions in both reactors, both in PFR and in CSTR. The phenomenon of conservatively perturbed-equilibrium is manifested in both PFR and CSTR. With the same rate constants, the acyclic system in PFR is characterized by higher values of "over equilibrium" conversion than the acyclic system in CSTR. Similarly, with the same rate constants, the cyclic system in PFR is characterized by higher values of "over equilibrium" conversion than the cyclic system in CSTR. The time of extremum onset is less in CSTR. This is true for acyclic and cyclic systems. The greater the difference between the initial concentrations of the two substances, the greater the "over equilibrium" concentration of the third substance, the initial concentration of which was equilibrium. At our values of kinetic parameters, the sensitivity of the time of occurrence of the extremum of the same reaction in different reactors (PFR and CSTR) is small (up to ≈5.6%), and at different reactions (acyclic and cyclic), but in one type of reactor (PFR or CSTR) - significant, reaching ≈46.2%.

The Ring Formation Mechanism in Cyclization of Berberine

Berberine hydrochloride is a natural alkaloid with significant antitumor activities against many types of cancer cells, can be synthesized by cyclic reaction with hydrochloride condensate and glyoxal as raw materials and copper chloride as catalyst. In this study, the transition and energy change for the each reaction step was calculated by the density functional theory program Dmol3 in Materials Studio 2017. and the results testified that there are two ring formation in the cycliztion process, and according to the result we proposed the mechanism of this cyclization reaction. We also use infrared and ultraviolet spectroscopy to monitor the reaction process in real time and prove the ring formation process. The reaction mechanism was firstly proposed at the basic results of above.

SORPTION-ENHANCED STEAM REFORMING OF ETHANOL FOR HYDROGEN PRODUCTION

In last years, sorption-enhanced steam reforming of ethanol (SESRE) has become an interesting alternative for the industry, since it offers high H2 purity with a simpler and smaller system. In this study CaO derived materials were synthesized to improve multicyclic CO2 sorption-desorption stability. A dispersant and inert phase (Ca12All4O33) was incorporated into CaO structure. The effects of CaO:Ca12Al14O33 ratio on the characteristics of the new absorbents and on their performance in sorption-enhanced steam reforming of ethanol were analyzed. The results obtained indicate that the absorbent 85% CaO – 15% Ca12Al14O33 had significantly improved cyclic reaction stability. Additionally, it was proved that with this adsorbent CO purity on wet basis was lower than 2 %, making it possible to attain in only one reaction stage the CO purity obtained after de WGS reactor.

PRESTRESS EFFECT ON THE THERMOMECHANICAL RESPONSE OF VISCOELASTIC CIRCULAR CYLINDRICAL SHELL UNDER HARMONIC LOADING

The problem of forced resonant vibrations and dissipative heating of a hinged viscoelastic elastomeric circular cylindrical shell is considered. The problem statement is based on the use of Kirchhoff–Love hypotheses and the concept of complex modules used to describe the cyclic reaction of a viscoelastic material to a harmonic loading. In the axisymmetric setting, it is assumed that there is a membrane force as a consequence of the applied tensile or prestress. The problem is solved in two stages: first the problem of mechanics is solved, and then for the found amplitudes of kinematic and force characteristics the dissipative function is constructed and both the steady-state and transient thermal problem is solved. As a result of solving the steady-state thermal problem, the amplitude-frequency and temperature-frequency curves are built.