The occurrence of perchlorate during drinking water electrolysis using BDD anodes

Electrochemical studies were carried out to estimate the risks of perchlorate formation in drinking water disinfected by direct electrolysis. Boron Doped Diamond (BDD) anodes were used in laboratory and commercially available cells at 20 °C. The current density was changed between 50 and 500 A m⁻². For comparison, other anode materials such as platinum and mixed oxide were also tested. It was found that BDD anodes have a thousandfold higher perchlorate formation potential compared with the other electrode materials that were tested. In long-term discontinuous experiments all the chloride finally reacted to form perchlorate. The same result was obtained when probable oxychlorine intermediates (OCl⁻, ClO₂⁻, ClO₃⁻) were electrolysed in synthetic waters in the ppm range of concentrations. The tendency to form perchlorate was confirmed when the flow rate of drinking water was varied between 100 and 300 L h⁻¹ and the temperature increased to 30 °C. In a continuous flow mode of operation a higher chloride concentration in the water resulted in a lower perchlorate formation. This can be explained by reaction competition of species near and on the anode surface for experiments both with synthetic and local drinking waters. It is concluded that the use of electrodes producing highly reactive species must be more carefully controlled in hygienically and environmentally oriented applications.     

Kinetics and mechanism of low-temperature ozone decomposition by Co-ions adsorbed on silica

Kinetics and mechanism of low-temperature ozone ((5–50) × 10⁻³ mol/m³ in the gas–air mixture) decomposition by Co-catalysts supported on silica have been studied. Co-ions adsorbed on silica react with surface oxygen species, thus resulting in an active catalyst. Low concentrations of Co-ions form a monolayer on the surface. Their specific catalytic activity remained constant, but sharply decreased at higher concentrations due to a formation of polynuclear Co-complexes. Ozone decomposition may occur either as a stoichiometric or catalytic process, depending on the ozone and catalyst concentrations. The turnover number increases with ozone concentration reaching a saturation point. It also increases with Co-concentration in the beginning, but drops at a concentration >1 × 10⁻⁴ mol/g. The mechanism of the reaction is discussed.     

FPGA realization of the LIRA neural classifier

Different types of neural networks can be used to classify images. We propose to apply LIRA (LImited Receptive Area) neural classifier to work with images. To accelerate the neural network functioning we propose a digital implementation of the LIRA neural classifier. We begin with a neuron design, and then continue with the neural network simulation. The advantage of neural network is its parallel structure and possibility of the training. FPGA (Field Programmable Gate Array) allows the implementation of these parallel algorithms in a single device. Speed of classification is one of the most important requirements in adaptive control systems based on computer vision. The contribution of this article is LIRA neural classifier implementation with FPGA for two classes to accelerate the training and recognition processes.     

Sorption properties of polymers based on N‐substituted maleimides

Physicochemical and functional properties of 2,2‐diallyl‐1,1,3,3‐tetraethylguanidinium chloride copolymers with N‐(n‐carboxyphenyl)maleimide, of N‐vinylpyrrolidone with N‐(n‐carboxyphenyl)maleimide, and of N‐vinylpyrrolidone with N‐phenylmaleimide have been investigated. Specific surface area and porosity of the copolymers under investigation have been determined by using the low‐temperature adsorption method. Electron microscope investigations in surfaces of the polymers have evinced that all of them have a spongy microstructure, the N‐vinylpyrrolidone copolymer with N‐(n‐carboxyphenyl)maleimide being the most homogeneous of these. Sorption capacity of the copolymers toward Re(VII) ions has been investigated. The process is described by the Langmuir isotherm. The pH is the most important parameter for sorption process of Re(VII). In the conjoint presence of Re(VII) and Mo(VI) in a solution of acid and ammoniac mediums, rhenium can be separated from molybdenum by using the sorbents under investigation at pH > 4.5 or at hydrochloric acid concentrations 0.1 mol L^?1 and more. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Photocatalytic hydrogen evolution from aqueous solutions of organophosphorous compounds

Photocatalytic hydrogen production from water solutions of dimethyl methylphosphonate (DMMP), trimethyl phosphate (TMP), triethyl phosphate (TEP), and radiation protective amine WR 2721, that imitate nerve chemical warfare agents was studied for the first time. Platinized titianium dioxide Degussa P25 was used as catalyst. No significant hydrogen evolution was detected without organic electron donors – sacrificial agents.     

Comparative study of permeability of derivatives of gamma-aminobutyric and gamma-hydroxybutyric acids through hemato-encephalic barrier]

The authors studied the permeability of the blood-brain barrier (CEB) to two nootropics: calcium ketogomopantothenate (KRA-Ca), a GABA derivative, and and calcium salt of oxybutyrate (OB-Ca), a derivative of GOBA. It was established that both preparations penetrate the CEB easily and are found in the brain at different intervals after their administration. However, essential differences in the distribution constant of these drugs were disclosed: KPA-Ca permeated the CEB more intensively and was accumulated in larger amounts in the late-term intervals.     

Effect of physically active media on yarn orientation strengthening

Conclusions The effect of deforming Oksalon yarn in Various physically active liquid media on its physicomechanical properties has been studied.The action of water or carbon tetrachloride, with simultaneous deformation of the complex yarn, aids in reducing the cementation of elementary filaments, and assists polymer orientation molecular order, and raises the physicomechanical properties of the yarn.In the stage of high-temperature stretching, an increase in the efficiency of orientation strengthening is observed as a result of preliminary deformation of the yarn in physically active media.Translated from Khimicheskie Volokna, No. 3, pp. 27–29, May–June, 1985.     

Artificial gravity loading increases the effects of the glutamate transporter inhibitors on the glutamate release and uptake in rat brain nerve terminals

The present study evaluated the effect of artificial gravity loading on transporter-mediated uptake and release of L-glutamate using the inhibitors of glutamate transporters as tools. The competitive nontransportable, DL-threo-beta-benzyloxyaspartate (DL-TBOA), and transportable, DL-threo-beta-hydroxyaspartate (DL-THA), inhibitors were demonstrated to better inhibit the L-[¹⁴C]glutamate uptake under centrifuge-induced hypergravity compared with the normal gravity control. The effect of DL-TBOA on depolarization-induced carrier-mediated L-[¹⁴C]glutamate release also increased after hypergravity loading in Na⁺- and low [Na⁺] NMDG- supplemented media. 10 µM DL-TBOA-induced decrease in L-[¹⁴C]glutamate release in Na⁺ — supplemented medium was 15.2±2.2 % in the control experiments and 26.2±3.9 % after centrifuge-induced loading (P≤0,05) and in low [Na⁺] medium was 37.0±2.5 % and 45.0±3.4 %, respectively.