ZIF-8-derived Fe-C catalysts: relationship between structure and catalytic activity toward the oxygen reduction reaction

The oxygen reduction reaction (ORR) activity of carbonized ZIF-8 (CZ) and its Fe-doped derivatives, CZ-A (doped with ammonium iron (II) sulphate) and CZ-B (doped with iron (II) acetate), were examined in both acidic (0.5 M H2SO4) and basic (0.1 M KOH) electrolytes using a rotating disk electrode setup. These data show that the ORR activity of the Fe-doped catalysts is higher than that of pure CZ, with a higher activity in basic than acidic electrolyte. Extensive materials characterization highlights important differences in the sample crystallinity, morphology, porosity, and chemical composition as a function of the deployed precursor. The performance of the prepared catalysts is also impacted by the Fe precursor selection, highlighting the importance of such synthetic parameters in controlling the density and identify of Fe-Nx active sites. These results demonstrate the potential application of Fe-doped carbonized ZIF-8 catalysts for the ORR in basic electrolyte and offer important knowledge for the future design of non-precious metal fuel cell electrocatalysts

A multi-spectroscopic study for the characterization and definition of production techniques of German ceramic sherds

The aim of this archaeometric study is to recover information regarding technological processes and raw materials used for the production of ceramic sherds coming from five central and Eastern German sites, between Lower Saxony and Saxony states. The ceramic fragments have been investigated by a multi-spectroscopic approach: Fourier transform infrared spectroscopy (FT-IR), micro-Raman spectroscopy and X-ray Fluorescence (XRF) were employed to characterize both ceramic bodies and glazes. Moreover the innovative application of Laser Induced Fluorescence (LIF) on ceramic findings has been proposed and evaluated. Chemical and mineralogical composition, as well as microstructure, of ceramic mixture and glaze are correlated to native material composition and firing temperature, which have become a fundamental features in archaeometric research and play a key role in understanding the provenance of the pottery and its production techniques.The multi-spectroscopic approach applied in this work has enabled the ability to characterize the ceramic sherds and to investigate through non-destructive techniques both ceramic glaze and matrix giving information regarding the raw materials and pigments/colourants used, and regarding firing temperature and technology. The present study carried on using complementary methods suggests different raw material sources and temperature kilns. These data are in agreement with the location of ceramic sites and with data in literature. Furthermore, the interesting results suggest that non-destructive techniques, such as LIF and Raman spectroscopy, are promising methods for ceramic and glaze characterization. (C) 2015 Elsevier B.V. All rights reserved

Track D Social Science, Human Rights and Political Science

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138414/1/jia218442.pd

Poetry and Family Photographs [In Bulgarian]

Evdokia Tosheva was born in 1942 in Lom, NW Bulgaria. She is retired as a hospital nurse. Her mother belonged to a rich Lom family. Her father was a cavalry officer from Belogradchik. The family was put under repression in the communist era. Now Evdokia is fond of writing poems, she loves Bulgarian landscapes, Belogradchik, and Bulgarian customs and folk traditions. The paper presents some of her poetry attempts for children and for adults. Beloved family photos illustrate her poems

Proinflammatory Cytokine Polymorphisms and Severity of Periodontitis in a Cohort of Bulgarian Patients

In this manuscript we are discussing our research of the presence of single nucleotide polymorphisms (SNPs) of two proinflammatory cytokines – interleukin 17F (IF-17F) and interleukin 23 (IL-23) in a cohort of Bulgarian patients