Frequency Dispersion of Impedance in a Molten Electrolyte

<p>It is an experimental fact that the impedance of an electrolyte as usually measured (by conductance bridge in a two electrode cell) is dependent on the frequency of the applied voltage. A quantity of fundamental physical significance in the elucidation of the structure of an electrolyte is the mobility of the conducting species. In order to know the mobilities of conducting species it is necessary to know the resistance of the particular electrolyte. However in order to establish the nature of the electrolyte i.e. its structure, resistance measurements are required which are precise and accurate and the variation of resistance (conductance) with temperature must be accurately know.</p>

Frequency Dispersion of Impedance in a Molten Electrolyte

<p>It is an experimental fact that the impedance of an electrolyte as usually measured (by conductance bridge in a two electrode cell) is dependent on the frequency of the applied voltage. A quantity of fundamental physical significance in the elucidation of the structure of an electrolyte is the mobility of the conducting species. In order to know the mobilities of conducting species it is necessary to know the resistance of the particular electrolyte. However in order to establish the nature of the electrolyte i.e. its structure, resistance measurements are required which are precise and accurate and the variation of resistance (conductance) with temperature must be accurately know.</p>

Synthesis Dependent Structural Magnetic and Electrical Properties of CR-Doped Lead-Free Multiferroic AlFeO3

Polycrystalline samples AlFe0.95Cr0.05O3 synthetized by a solid state (SR) and a co-precipitation (cop) method show an orthorhombic system in space group Pc21n. It was found that, the cation distribution and magnetic ordering vary toughly on the synthesis conditions. We deployed impedance spectroscopy in studying the dielectric behavior of AlFe0.95Cr0.05O3. The significant results of this work are: for both samples, permittivity and dielectric loss are very sensitive to the temperature and frequency variation. The existence of supplementary imperfections and conducting species in AFCr5-s ceramics led to important dielectric permittivity in AFCr5-s. Values of the activation energy determined at low temperature point toward oxygen vacancies motion in slight range, however at high temperature, such a motion turns to long-range one. The dielectric response in case of AFCr5-s was assigned throw complex impedance plots to the grain as well as grain boundary. Conversely, additional individual pores similarly participate to dielectric belongings of AFCr5-cop.

An inventory of avian species in Aldesa Valley, Saudi Arabia

Conducting species inventories is important to provide baseline information essential for management and conservation. Aldesa Valley lies in the Tabuk Province of northwest Saudi Arabia and because of the presence of permanent water, is thought to contain high avian richness. We conducted an inventory of avian species in Aldesa Valley, using timed area-searches during May 10–August 10 in 2014 and 2015 to detect species occurrence. We detected 6860 birds belonging to 19 species. We also noted high human use of this area including agriculture and recreational activities. Maintaining species diversity is important in areas receiving anthropogenic pressures, and we encourage additional surveys to further identify species occurrence in Aldesa Valley.

Accuracy in determining absorbed irradiation dose at different temperature measurements using ethanol chlorobenzene - oscillotitrator system

Ethanol-chlorobenzene/oscillotitrator dosimetry system is widely used in controlling the irradiation process in gamma facilities. The ethanol-chlorobenzene dosimetry system provides a reliable means of measuring absorbed dose. It is based on a process of radiolytic formation of hydrochloric acid in aqueous ethanolic solutions of chlorobenzene by ionizing radiation. The irradiation temperature dependence of dosimeter response is a complex function of dose and temperature for each concentration of chlorobenzene. At different temperature the mobility of conducting species from hydrochloric acid is changed leading to different oscillotitrator deflections during high-frequency conductometric readout. In this paper, we examined the influence of temperature on the calculation of the radiation dose. We showed that the temperature significantly influenced the measurement results, and that the calibration curve has to be formed at the irradiation temperature in order to obtain precise values of the absorbed dose.

First examples of organosilica-based ionogels: synthesis and electrochemical behavior

The article describes the synthesis and properties of new ionogels for ion transport. A new preparation process using an organic linker, bis(3-(trimethoxysilyl)propyl)amine (BTMSPA), yields stable organosilica matrix materials. The second ionogel component, the ionic liquid 1-methyl-3-(4-sulfobutyl)imidazolium 4-methylbenzenesulfonate, [BmimSO3H][PTS], can easily be prepared with near-quantitative yields. [BmimSO3H][PTS] is the proton conducting species in the ionogel. By combining the stable organosilica matrix with the sulfonated ionic liquid, mechanically stable, and highly conductive ionogels with application potential in sensors or fuel cells can be prepared.

What is the true nature of conducting proton in perovskite ceramic membrane: hydroxyl ion or interstitial proton ?

ABSTRACTThe proton conducting perovskites are widely investigated due to their high potential as electrolyte membranes of fuel cells, water steam electrolysers and CO2/syngas converters. Our comprehensive spectroscopic (Raman, IR, neutron), thermogravimetric, elastic and quasi-elastic neutron diffusion as well as conductivity studies performed on Ln/RE- modified zirconate ceramics with controlled densification (90-99% of theoretical density) reveal the important differences between the surface and bulk protonic species. The results clearly show that trivialization of the protonation process complexity can favorite the adsorption of the surface protonic species (hydroxide, hydrocarbonates, etc), prohibit the incorporation of bulk protons, i.e. species responsible for the proton conduction and confuse the understanding of fundamental aspects concerning the proton conductors such as the true nature of conducting species. Our studies reveal that OH- ions are located at the surface of poor densified ceramic and the bulk conducting protons exhibit an ionic, free of covalent-bonded nature.

Electromigration induced microstructure and morphological changes in eutectic SnPb solder joints

Simultaneous direct current stressing with thermal aging accelerates the migration of conducting species resulting in significant microstructural coarsening. Because of the synergistic fields influence, such coarsening begins from the anode and propagates toward the cathode. Prolonged current stressing with 104 A/cm2 at 150 °C causes the inter-lamellar eutectic SnPb to become a two-layer structure, with a Pb-rich layer adjacent to the anode and an Sn-rich layer adjacent to the cathode. This mass movement causes hillock/valley formation, and the extents of such surface undulations increase with increases in the time duration of current stressing as well as with the joint thickness. In thinner solder joints these events occur sooner, although the extents of surface undulations depend on the thickness of joints. In addition, Cu present in the substrate and in the intermetallic layer at the cathode migrates to form Cu6Sn5 within the Sn-rich layer, in a region close to the Pb-rich layer.

Internal Cation Mobilities in Molten (K, Dy1/3)Cl

Internal cation mobility ratios in the molten system KCl-DyCl3 have been measured at 1093 K by Klemm's countercurrent electromigration method. From these, and data available on the conductivities and molar volumes of the mixtures, the internal mobilities b of both cations have been calculated. With increasing concentration of Dy, bK decreases. The decrease of bK is attributed to the tranquilization effect by Dy3+ ions which strongly interact with Cl- ions. With increasing concentration of K+ , bDy decreases; this may be attributed to the stronger association of Dy3+ with C- ions due to the enhanced charge asymmetry of the two cations neighboring to the C- ions. It could not been clarified whether a species such as [DyCl6]3- is also an electrically-conducting species in the K+ rich range.