INPUT SELECTION BY EPR-MOGA

The growing availability of field data, from information and communication technologies (ICTs) in "smart'' urban infrastructures, allows data modeling to understand complex phenomena and to support management decisions. Among the analyzed phenomena, those related to storm water quality modeling have recently been gaining interest in the scientific literature. Nonetheless, the large amount of available data poses the problem of selecting relevant variables to describe a phenomenon and enable robust data modeling. This paper presents a procedure for the selection of relevant input variables using the multi-objective evolutionary polynomial regression (EPR-MOGA) paradigm. The procedure is based on scrutinizing the explanatory variables that appear inside the set of EPR-MOGA symbolic model expressions of increasing complexity and goodness of fit to target output. The strategy also enables the selection to be validated by engineering judgement. In such context, the multiple case study extension of EPR-MOGA, called MCS-EPR-MOGA, is adopted. The application of the proposed procedure to modeling storm water quality parameters in two French catchments shows that it was able to significantly reduce the number of explanatory variables for successive analyses. Finally, the EPR-MOGA models obtained after the input selection are compared with those obtained by using the same technique without benefitting from input selection and with those obtained in previous works where other data-modeling techniques were used on the same data. The comparison highlights the effectiveness of both EPR-MOGA and the input selection procedure

Surface passivation effect by fluorine plasma treatment on ZnO for efficiency and lifetime improvement of inverted polymer solar cells

Zinc oxide (ZnO) is an important material for polymer solar cells (PSCs) where the characteristics of the interface can dominate both the efficiency and lifetime of the device. In this work we study the effect of fluorine (SF6) plasma surface treatment of ZnO films on the performance of PSCs with an inverted structure. The interaction between fluorine species present in the SF6 plasma and the ZnO surface is also investigated in detail. We provide fundamental insights into the passivation effect of fluorine by analyzing our experimental results and theoretical calculations and we propose a mechanism according to which a fluorine atom substitutes an oxygen atom or occupies an oxygen vacancy site eliminating an electron trap while it may also attract hydrogen atoms thus favoring hydrogen doping. These multiple fluorine roles can reduce both the recombination losses and the electron extraction barrier at the ZnO/fullerene interface improving the selectivity of the cathode contact. Therefore, the fabricated devices using the fluorine plasma treated ZnO show high efficiency and stable characteristics, irrespective of the donor : acceptor combinations in the photoactive blend. Inverted polymer solar cells, consisting of the P3HT:PC71BM blend, exhibited increased lifetime and high power conversion efficiency (PCE) of 4.6%, while the ones with the PCDTBT:PC71BM blend exhibited a PCE of 6.9%. Our champion devices with the PTB7:PC71BM blends reached a high PCE of 8.0% and simultaneously showed exceptional environmental stability when using the fluorine passivated ZnO cathode interlayers

The Effects of Non-Aqueous Solvents on The Configuration of Bovine Serum Albumin

94 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1962.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD

China’s Land Uses in the Multi-Region Input–Output Framework

The finite resource of land is subject to competing pressures from food demand, urbanization, and ecosystem service provision. Linking the land resource use to the whole production chain and final consumption of various products and services offers a new perspective to understand and manage land uses. This study conducted a systematic analysis of land uses at the provincial level in China using the multi-region input–output model in 2012. Land use patterns related to the sectoral production and consumption in different provinces were examined. The results indicated that the land use transfers between different provinces in China have formed a highly interacting network. Products and services involved in the inter-provincial trades in China contained 2.3 million km2 land uses, which constituted approximately 40% of the total national land uses that were finally consumed in China. Agriculture was the most direct land use intensive sector, and industry was the most indirect land use intensive sector. Land resource-scarce provinces with low per capita land availability have outsourced parts of their land uses by net importing lands from other provinces. The results have important policy implications towards sustainable land uses in China