University of Patras

About: University of Patras is a education organization based out in Pátrai, Greece. It is known for research contribution in the topics: Population & Catalysis. The organization has 13372 authors who have published 31263 publications receiving 677159 citations. The organization is also known as: Panepistímio Patrón.

Vertical Flow Constructed Wetlands: Eco-engineering Systems for Wastewater and Sludge Treatment

Abstract: Vertical flow constructed wetlands for wastewater and sludge treatment represent a relatively new and still growing technology. Vertical Flow Constructed Wetlands is the first book to present the state-of-the-art knowledge regarding vertical flow constructed wetlands theory and applications. In this book, you will learn about vertical flow systems with information about application and performance. Vertical Flow Constructed Wetlands also includes information on how different countries are applying the technology, with design guidelines to illustrate best practices worldwide. A focus on water conservation through reuse of treated water showcases the benefit of vertical flow construction, which has greatly increased the attractiveness of the technology in recent years. Features: all state-of-the-art knowledge regarding vertical flow constructed wetlands gathered in one book; a review of various constructed wetland approaches, including information about applications and performance, helps clarify what is currently known about constructed wetland principles and design; and discussion of how to manage the treated wastewater leaving the vertical flow for increasing biodiversity, providing food and habitat for birds, and producing harvestable biomass or crops. It includes case studies of constructed wetlands in developing countries.

A Simple and Effective Modification of PCBM for Use as an Electron Acceptor in Efficient Bulk Heterojunction Solar Cells

Abstract: [6,6]-phenyl-C-61-butyric acid methyl ester (PCBM) and poly(3-hexylthiophene) (P3HT) are the most widely used acceptor and donor materials, respectively, in polymer solar cells (PSCs). However, the low LUMO (lowest unoccupied molecular orbital) energy level of PCBM limits the open circuit voltage (Voc) of the PSCs based on P3HT. Herein a simple, low-cost and effective approach of modifying PCBM and improving its absorption is reported which can be extended to all fullerene derivatives with an ester structure. In particular, PCBM is hydrolyzed to carboxylic acid and then converted to the corresponding carbonyl chloride. The latter is condensed with 4-nitro-4’-hydroxy-α-cyanostilbene to afford the modified fullerene F. It is more soluble than PCBM in common organic solvents due to the increase of the organic moiety. Both solutions and thin films of F show stronger absorption than PCBM in the range of 250–900 nm. The electrochemical properties and electronic energy levels of F and PCBM are measured by cyclic voltammetry. The LUMO energy level of F is 0.25 eV higher than that of PCBM. The PSCs based on P3HT with F as an acceptor shows a higher Voc of 0.86 V and a short circuit current (Jsc) of 8.5 mA cm−2, resulting in a power conversion efficiency (PCE) of 4.23%, while the PSC based on P3HT:PCBM shows a PCE of about 2.93% under the same conditions. The results indicate that the modified PCBM, i.e., F, is an excellent acceptor for PSC based on bulk heterojunction active layers. A maximum overall PCE of 5.25% is achieved with the PSC based on the P3HT:F blend deposited from a mixture of solvents (chloroform/acetone) and subsequent thermal annealing at 120 °C.