Simulation-Based Shading Loss Analysis of a Shingled String for High-Density Photovoltaic Modules

Shingled photovoltaic (PV) modules with increased output have attracted growing interest compared to conventional PV modules. However, the area per unit solar cell of shingled PV modules is smaller because these modules are manufactured by dividing and bonding solar cells, which means that shingled PV modules can easily have inferior shading characteristics. Therefore, analysis of the extent to which the shadow affects the output loss is essential, and the circuit needs to be designed accordingly. In this study, the loss resulting from the shading of the shingled string used to manufacture the shingled module was analyzed using simulation. A divided cell was modeled using a double-diode model, and a shingled string was formed by connecting the cell in series. The shading pattern was simulated according to the shading ratio of the vertical and horizontal patterns, and in the case of the shingled string, greater losses occurred in the vertical direction than the horizontal direction. In addition, it was modularized and compared with a conventional PV module and a shingled PV module. The results confirmed that the shingled PV module delivered higher shading output than the conventional PV module in less shade, and the result of the shading characteristic simulation of the shingled PV module was confirmed to be accurate within an error of 1%.

Cathodic electroorganic reaction on silicon oxide dielectric electrode

The faradaic reaction at the insulator is counterintuitive. For this reason, electroorganic reactions at the dielectric layer have been scarcely investigated despite their interesting aspects and opportunities. In particular, the cathodic reaction at a silicon oxide surface under a negative potential bias remains unexplored. In this study, we utilize defective 200-nm-thick n+-Si/SiO2 as a dielectric electrode for electrolysis in an H-type divided cell to demonstrate the cathodic electroorganic reaction of anthracene and its derivatives. Intriguingly, the oxidized products are generated at the cathode. The experiments under various conditions provide consistent evidence supporting that the electrochemically generated hydrogen species, supposedly the hydrogen atom, is responsible for this phenomenon. The electrogenerated hydrogen species at the dielectric layer suggests a synthetic strategy for organic molecules.

Advanced 96-microtiter plate based bioelectrochemical platform reveals molecular short cut of electron flow in cytochrome P450 enzyme

We developed a novel 96-well microtiter plate based bioelectrochemical platform with a vertical divided cell three-electrode architecture and a 96-multipotentiostat to perform fully parallelised bioelectrocatalytic screenings on redox enzymes.

Cathodic hydrogen production by simultaneous oxidation of methyl red and 2,4-dichlorophenoxyacetate in aqueous solutions using PbO2, Sb-doped SnO2 and Si/BDD anodes. Part 2: hydrogen production

Efficient production of H2 from the electrochemical oxidation of organic compounds with non-active anodes in a divided cell.

Electrochemical Corey–Winter reaction. Reduction of thiocarbonates in aqueous methanol media and application to the synthesis of a naturally occurring α-pyrone

An electrochemical version of the Corey–Winter reaction was developed giving excellent results in aqueous methanol media (MeOH/H2O (80:20) with AcOH/AcONa buffer 0.5 M as supporting electrolyte), using a reticulated vitreous carbon as cathode in a divided cell. The electrochemical version is much more environmentally friendly than the classical reaction, where a large excess of trialkyl phosphite as reducing agent and high temperatures are required. Thus, cathodic reduction at room temperature of two cyclic thiocarbonates (−1.2 to −1.4 V vs Ag/AgCl) afforded the corresponding alkenes, trans-6-(pent-1-enyl)-α-pyrone and trans-6-(pent-1,4-dienyl)-α-pyrone, which are naturally occurring metabolites isolated from Trichoderma viride and Penicillium, in high chemical yield and with excellent stereo selectivity.

Rechargeable organic–air redox flow batteries

A rechargeable organic–air flow battery based on aqueous electrolytes is proposed and tests are conducted in a divided cell with a three-electrode configuration.

Flow Chemistry

Arturo Macchi of the University of Ottawa and Dominique M. Roberge of Lonza sum­marized (Org. Process Res. Dev. 2014, 18, 1286) a “toolbox approach” for the evolution from batch to continuous chemical synthesis. Michael D. Organ of York University developed (Org. Process Res. Dev. 2014, 18, 1315) a flow reactor with inline analyt­ics, and Timothy D. White of Eli Lilly described (Org. Process Res. Dev. 2014, 18, 1482) the continuous production of solid products under flow conditions. Electrochemical reduction and oxidation are particularly easy under flow conditions. Steven V. Ley of the University of Cambridge oxidized (Org. Lett. 2014, 16, 4618) 1 under flow conditions, then condensed the product with tryptamine 2 to pre­pare the indole alkaloid Nazlinine 3. Thomas Wirth of Cardiff University electrolyzed (Org. Process Res. Dev. 2014, 18, 1377) the carbonate 4 in a non-divided cell to return the deprotected phenol 5. Timothy Noël of the Eindhoven University of Technology gathered (Chem. Eur. J. 2014, 20, 10562) an overview of photochemical transformations under flow condi­tions. Kevin I. Booker-Milburn of the University of Bristol observed (Chem. Eur. J. 2014, 20, 15226) superior yields for the coupling of 6 with 7 to form 8 under flow compared to batch conditions. Koichi Fukase of Osaka University and Ilhyong Ryu of Osaka Prefecture University converted (Chem. Eur. J. 2014, 20, 12750) 9 selectively to 10 under flow conditions. Alexei A. Lapkin, also of the University of Cambridge, optimized (Org. Process Res. Dev. 2014, 18, 1443) the singlet oxygen conversion of 11 to 12. Shawn K. Collins of the Université de Montréal cyclized (Org. Process Res. Dev. 2014, 18, 1571) 13 to 14. There have been several advances in the use of enzymes under flow conditions. Rodrigo O. M. A. de Souza of the Federal University of Rio de Janeiro found (Org. Process Res. Dev. 2014, 18, 1372) that lipase in a microemulsion-based organogel efficiently converted coupled 15 with 16 to make 17. Timothy F. Jamison of MIT developed (Org. Lett. 2014, 16, 6092) a catch-and-release protocol for the reductive amination of 18 with 19 to give 20.

In situ diesel desulfurization in divided-cell trickle bed electrochemical reactor

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Crude oil contains natural organic components such as organosulfur compounds, and these compounds largely remain in refined petroleum products such as gasoline, diesel and jet fuel products. During fuel combustion, sulfur was emitted as sulfur dioxide or sulfate, which is one of the main causes of air pollution and acid rain. The oil price is inversely proportional to the sulfur content because upgrade of heavy, high-sulfur-containing oil is much more difficult than the light feeds. Many regulations have been established by different countries to control sulfur level in fuels; in the U.S. the maximum required concentration is 15 ppm (parts per million) sulfur in diesel. The most commonly used technology to remove sulfur from diesel fuel is hydrodesulfurization (HDS). The major drawback of HDS is the harsh operating conditions that require high temperatures and pressures with consumption of a large amount of hydrogen. The HDS process is only able to reduce sulfur content to about 500 ppm in diesel. Further reduction requires more intense processing with a significant increase in hydrogen usage, particularly in removing the refractory sulfur compounds, such as benzothiophene (BT), dibenzothiophene (DBT), and their alkyl derivatives. In this dissertation, an efficient and cost-effective process for oxidation of organosulfur compounds (OSCs) in diesel has been developed and investigated. A divided-cell trickle bed electrochemical reactor (TBER) was first developed to produce hydrogen peroxide. The divided-cell trickle bed electrochemical reactor (TBER) has a porous cathode composed of carbon black and polytetrafluoroethylene. It was designed and fabricated to have hydrophobic and hydrophilic components for liquid and gas flows. Hydrogen peroxide generation was successfully demonstrated from reducing oxygen in concentrated alkaline electrolyte solutions. An important feature of the reactor was a cathode made with stainless steel meshes that divide it into four packed-bed cells. This division into sectional cathode resulted in a concentration of hydrogen peroxide that more than doubles that produced in an undivided cathode. The much-improved performance was attributed to the even distribution of the electrolyte and oxygen in the cathode bed, as well as an effective mass transport of oxygen from the gas phase to the electrolyte-cathode interface. After the successful production of hydrogen peroxide, the TBER was employed for in situ oxidation desulfurization of diesel fuel. The possibility of diesel desulfurization with in situ generated hydrogen peroxide in the presence of DBT was systematically investigated. The maximum concentration of hydrogen peroxide after two-hour electrolysis was 31.79 mM without diesel, whereas in the presence of 10% diesel (by volume) in the electrolyte was 18.0 mM. DBT was successfully oxidized in situ in the TBER, with conversion efficiency of 97.75% in six hours. To further improve the efficiency of the hydrogen peroxide production, cathode was modified with MnO2, a potentially more active catalyst for hydrogen peroxide production in alkaline electrolytes. It was found that incorporation of MnO2 indeed promoted in situ oxidation of DBT which was attributed to more hydrogen peroxide produced. The results showed the in situ oxidation process in the divided-cell TBER is a promising and environmentally friendly approach for desulfurization of diesel.