Continuous thickening of activated sludge by electro-flotation

The present study was conducted for thickening of activated sludge by continuous electro-flotation (EF) process. The effects of some key factors such as initial pH, current density, operating time, electrode type (stainless steel and graphite) and operation conditions on the sludge thickening by determine of sludge volume reduction (SVR) and sludge solid concentration (SSC) and as well as removal of chemical oxygen demand (COD), total solids (TS), total suspended solids (TSS) and color were investigated. The results showed that the process has a good efficiency. The highest amount of SVR efficiency (89.3) and SSC (38 g L-1) were achieved at current density of 8 mA cm(-2) in 15 min for stainless steel. Moreover, as surface/volume ratio increased, better thickening happened because increases both mass transfer and electro-generation of O-2 and H-2 at the surface of electrodes in low applied current density. Accordingly, consumed electrical energy was 0.15-1 kW h m(-3). Although suitable cell design is entirely essential, the use of chemicals and temperature increase are not effective. Consequently, EF is a comparatively appropriate process for thickening; in the water separated from the process, the amounts pertaining to COD, TS, TSS and color were respectively 112, 1601, 140 mg L-1 and 5 TCU which are useable for subsequent different consumptions. Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved

Set-valued orthogonal additivity

We study the set-valued Cauchy equation postulated for orthogonal vectors. We give its general solution as well as we look for selections of functions satisfying the equation

Set optimization - a rather short introduction

Recent developments in set optimization are surveyed and extended including various set relations as well as fundamental constructions of a convex analysis for set- and vector-valued functions, and duality for set optimization problems. Extensive sections with bibliographical comments summarize the state of the art. Applications to vector optimization and financial risk measures are discussed along with algorithmic approaches to set optimization problems

Orthogonalities and functional equations

In this survey we show how various notions of orthogonality appear in the theory of functional equations. After introducing some orthogonality relations, we give examples of functional equations postulated for orthogonal vectors only. We show their solutions as well as some applications. Then we discuss the problem of stability of some of them considering various aspects of the problem. In the sequel, we mention the orthogonality equation and the problem of preserving orthogonality. Last, but not least, in addition to presenting results, we state some open problems concerning these topics. Taking into account the big amount of results concerning functional equations postulated for orthogonal vectors which have appeared in the literature during the last decades, we restrict ourselves to the most classical equations

Estrogen- and Progesterone (P4)-Mediated Epigenetic Modifications of Endometrial Stromal Cells (EnSCs) and/or Mesenchymal Stem/Stromal Cells (MSCs) in the Etiopathogenesis of Endometriosis

Endometriosis is a common chronic inflammatory condition in which endometrial tissue appears outside the uterine cavity. Because ectopic endometriosis cells express both estrogen and progesterone (P4) receptors, they grow and undergo cyclic proliferation and breakdown similar to the endometrium. This debilitating gynecological disease affects up to 15% of reproductive aged women. Despite many years of research, the etiopathogenesis of endometrial lesions remains unclear. Retrograde transport of the viable menstrual endometrial cells with retained ability for attachment within the pelvic cavity, proliferation, differentiation and subsequent invasion into the surrounding tissue constitutes the rationale for widely accepted implantation theory. Accordingly, the most abundant cells in the endometrium are endometrial stromal cells (EnSCs). These cells constitute a particular population with clonogenic activity that resembles properties of mesenchymal stem/stromal cells (MSCs). Thus, a significant role of stem cell-based dysfunction in formation of the initial endometrial lesions is suspected. There is increasing evidence that the role of epigenetic mechanisms and processes in endometriosis have been underestimated. The importance of excess estrogen exposure and P4 resistance in epigenetic homeostasis failure in the endometrial/endometriotic tissue are crucial. Epigenetic alterations regarding transcription factors of estrogen and P4 signaling pathways in MSCs are robust in endometriotic tissue. Thus, perspectives for the future may include MSCs and EnSCs as the targets of epigenetic therapies in the prevention and treatment of endometriosis. Here, we reviewed the current known changes in the epigenetic background of EnSCs and MSCs due to estrogen/P4 imbalances in the context of etiopathogenesis of endometriosis