A Study of the Interactions Between the Double Bonds in Unsaturated Ketones

The interactions between C=C and C=O double bonds in several unsaturated ketones have been studied by comparing MIND0/2 caloulations wiith ionisation potentials determined by photoelectron spectroscopy (PES). With one exception (norbornadienone) the direct through-space interactions in conjugated .ketones appear to be negligible, the double bonds couple hyperoonjugatively via the intervening a bonds. This kind of approach should prove useful for studying other long range interactions

Effect of Some Anions on the Chlorate Cell Process

The effect of some non-corresponding ionic species on the anodic process in the chlorate producing electrolytic cells has been investigated. It was shown that increasing concentration of anions such as chromate, nitrate and phosphate results in an increase in the oxygen evolution rate. The effect exhibits an asymptotic tendency at higher concentrations. The resemblance of the curve with the adsorption isotherm suggests anion adsorption and its catalytic effect on charge transfer as a possible cause of increasing electrochemical oxidation of available chlorine. The latter results in a corresponding decrease of the current efficiency of chlorate production. Hence, inspite of the benefitial effect of buffering by some of the anions on the chemical conversion of available chlorine into chlorate, the non-corresponding anion concentrations should be kept as low as possible

Genetic and epigenomic modifiers of diabetic neuropathy

Diabetic neuropathy (DN), the most common chronic and progressive complication of diabetes mellitus (DM), strongly affects patients’ quality of life. DN could be present as peripheral, autonomous or, clinically also relevant, uremic neuropathy. The etiopathogenesis of DN is multifactorial, and genetic components play a role both in its occurrence and clinical course. A number of gene polymorphisms in candidate genes have been assessed as susceptibility factors for DN, and most of them are linked to mechanisms such as reactive oxygen species production, neurovascular impairments and modified protein glycosylation, as well as immunomodulation and inflammation. Different epigenomic mechanisms such as DNA methylation, histone modifications and non-coding RNA action have been studied in DN, which also underline the importance of “metabolic memory” in DN appearance and progression. In this review, we summarize most of the relevant data in the field of genetics and epigenomics of DN, hoping they will become significant for diagnosis, therapy and prevention of DN

Environmental Education in Serbian Primary Schools: Challenges and Changes in Curriculum, Pedagogy, and Teacher Training

The protection of human health and the preservation of the environment are topics that form anintegral part of the primary school curriculum in Serbia. However, research studies have shown thatstudents do not have enough knowledge to contribute to the development of a healthy lifestyle andenvironmental awareness. The latest changes in school policy and curricula confirm that the relevanceof environmental education has been recognized, but changes in school practice are yet to come. Thisarticle discusses the challenges encountered in the implementation of the intended curriculum andoffers suggestions for changes to the curriculum, pedagogy, and teacher training in order to enhanceenvironmental educationThis is the peer-reviewd version of the artivle: Stanišić, Jelena, и Slavica Maksić. 2014. „Environmental Education in Serbian Primary Schools: Challenges and Changes in Curriculum, Pedagogy, and Teacher Training“. Journal of Environmental Education 45(2):118–31. doi: 10.1080/00958964.2013.829019.Related to published version: [ http://ipir.ipisr.org.rs/handle/123456789/240

Clar's Theory, STM Images, and Geometry of Graphene Nanoribbons

We show that Clar's theory of the aromatic sextet is a simple and powerful tool to predict the stability, the \pi-electron distribution, the geometry, the electronic/magnetic structure of graphene nanoribbons with different hydrogen edge terminations. We use density functional theory to obtain the equilibrium atomic positions, simulated scanning tunneling microscopy (STM) images, edge energies, band gaps, and edge-induced strains of graphene ribbons that we analyze in terms of Clar formulas. Based on their Clar representation, we propose a classification scheme for graphene ribbons that groups configurations with similar bond length alternations, STM patterns, and Raman spectra. Our simulations show how STM images and Raman spectra can be used to identify the type of edge termination

Electrochemical H/D isotope effects in PEM fuel cell

An electrochemical H/D separation system consisting of electrolyzer and PEM fuel cell has been proposed. Isotope separation could be important as a part of the energy saving process in an energy-hydrogen-energy cycle. Any transfer of energy into hydrogen or vice versa induces change of the H/D isotope ratio, which can be considered, as a method to produce heavy water as by-product. In this way, the separation efficiency can contribute to the overall efficiency of the cycle. (c) 2008 Elsevier B.V. All rights reserved

A study on the Co-W activated Ni electrodes for the hydrogen production from alkaline water electrolysis - Energy saving

Hydrogen is considered to be the most promising candidate as a future energy carrier. One of the most used technologies for the electrolytic hydrogen production is alkaline water electrolysis. However, due to high energy requirements of about 4.5-5 kWh/Nm(3) H(2) in most industrial electrolysers, the cost of hydrogen produced in such a way is high. There are various attempts to overcome this problem, like zero-gap cell geometry, development of new diaphragm materials, development of new electrocatalytic materials for electrodes, etc. In continuous search to improve this process using advanced electrocatalytic materials for the hydrogen evolution reaction (HER), based on transition metal series, catalyst based of cobalt and wolfram was investigated as cathode material. On the basis of the results of our experiments, there is a strong indication that the Co-W catalyst reduces energy needs per mass unit of hydrogen produced for more than 20% in some cases. Objective of this work was to investigate the electrocatalytic efficiency using quasi-potentiostatic, galvanostatic and impedance spectroscopy techniques. Results are presented to show the Tafel slopes, the exchange current densities, the apparent energy of activation, the apparent electrochemical surface and the stability of Co-W catalyst. Results suggest to significant catalytic performance not only from the increase of the real surface area of electrodes, but also from the true catalytic effect of the Co-W catalyst. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved

Raising efficiency of hydrogen generation from alkaline water electrolysis - Energy saving

This paper presents an attempt to make the alkaline electrolytic production of hydrogen more efficient by adding in situ activating compounds in ionic and complex form Cobalt and tungsten based ionic activators (i a) added directly into the electrolyte during the electrolytic process reduce energy requirements per mass unit of hydrogen produced for about 15% compared to non activated system for a number of current densities in a wide temperature range Energy saving is higher at higher temperatures and on higher current densities Structural and morphological characteristic of deposit formed on the cathode during the electrolytic process reveal very interesting and unique pattern with highly developed surface area and uniform distribution of the pores Obtained deposit also exhibit a long term stability (C) 2010 Professor T Nejat Veziroglu Published by Elsevier Ltd All rights reserve