Search results for "electric [charge]"
showing 10 items of 729 documents
Counterion transport numbers of poly(acrylic acid)-grafted porous ion-exchange membranes as determined from current step measurements
1997
Abstract The effect of an electric current on the concentration polarization of the external bathing solutions and the permselectivity of poly(acrylic acid)-grafted porous ion-exchange membranes has been studied. The experimental approach is based on the transient behavior of the total electric potential drop through the membrane cell when a current step is imposed from external nonpolarizable electrodes. When this voltage drop is recorded as a function of time, a transition time characteristic of each membrane system is obtained. From this time, the counterion transport number for the salt solution (KClH2O) in the membrane can be obtained. The theoretical modeling is based on the time-dep…
Molecular Mobility in Oriented and Unoriented Membranes Based on Poly[2-(Aziridin-1-yl)ethanol]
2021
Unoriented and oriented membranes based on dendronized polymers and copolymers obtained by chemical modification of poly[2-(aziridin-1-yl) ethanol] (PAZE) with the dendron 3,4,5-tris[4-(n-dodecan-1-yloxy)benzyloxy]benzoate were considered. DSC, XRD, CP-MAS NMR and DETA, contribute to characterize the tendency to crystallize, the molecular mobility of the benzyloxy substituent, the dendritic liquid crystalline group and the clearing transition. The orientation of the mesogenic chain somewhat hindered this molecular motion, especially in the full substituted PAZE. The fragility, free volume and thermal expansion coefficients of these membranes near the glass transition are related to the orie…
The role of intermolecular forces in contact electrification on polymer surfaces and triboelectric nanogenerators
2019
This research was supported by the European Regional Development Fund within the project ‘‘Hybrid energy harvesting systems’’ 1.1.1.1./16/A/013.
Innovative Combination of Three Alternating Current Relaxation Techniques: Electrical Charge, Mass, and Color Impedance Spectroscopy. Part I: The Tool
2009
Technical details concerning the simultaneous acquisition of three impedance functions (electrochemical impedance spectroscopy, alternating current electrogravimetry or mass impedance, and alternating current colorimetry or color impedance) are presented. The analysis of each type of impedance function gives interesting information about the species participating during the electrochemical processes. Furthermore, obtaining three impedance functions in situ allows the crossed impedance functions to be calculated. These functions are especially useful in detecting delays between the color, mass, and electrical charge response of the system to the same perturbation, and it allows species parti…
Usefulness of F(dm/dQ) Function for Elucidating the Ions Role in PB Films
2007
The conversion process of "insoluble" prussian blue (PB) films into the "soluble" structure has been followed by the simultaneous measurement of current and mass changes during voltammetric experiments and focusing on the possibilities of the use of the instantaneous mass/electrical charge ratio at each potential. A similar procedure was used for the analysis of the mechanism of reduction of PB films to the Everitt's salt form and to follow the partial dissolution of iron species during the oxidation to the prussian yellow form. The possibility of covering PB films by Nafion membranes, which make difficult the transport of anions through it, allows us to discern the role of anions in the so…
Dielektrische Relaxation und aromatischer Bindungszustand der Amino- und Hydroxylgruppe
1965
Bei funf Wellenlangen im Bereich von 60 cm bis 7 mm wurde in benzolischer Losung bei 20 °C die dielecktrische Absorption von Benzolderivaten gemessen, die Amino- oder Hydroxylgruppen enthalten. Danach erfolgt die elektrische Dipolorientierung bei N, N'-Dimethylanilin, Diphenylamin und ver wandten Molekulen in der Art, das die drei Bindungen des Stickstoffs uber die ebene Anordnung hinweg umklappen. Ebenso kann auch das Relaxationsverhalten von Anilin beschrieben werden. Voraussetzung fur diese Inversion ist die mesomere Wechselwirkung zwischen dem Stickstoff und einem aromatischen ϕ-Elektronen-system. Dagegen ergeben die Meswerte keinen Hinweis darauf, das bei der Hydroxylgruppe auch eine s…
The emission reduction potentials of First Generation Electric Aircraft (FGEA) in Finland
2020
Under the looming climate crisis, aviation needs to find new solutions to cut its greenhouse gas emissions. One pathway towards zero emissions is the use of electric aircraft. While current battery technology will not allow for medium and long-haul flights at full capacity, on short-haul routes First Generation Electric Aircraft (FGEA) could play a significant role in the near future. Current FGEA under development could carry 9–19 passengers on distances of 400–1046 km by 2025. This study focuses on the emissions reduction potentials of FGEA in Finland. It compares the carbon dioxide equivalent (CO2-eq) emissions and real travel times (RTT) from door-to-door of FGEA on 47 routes with exist…
Protein/Hydration Water Dynamics in Hard Confinement: Dielectric Relaxations and Picoseconds Hydrogen Fluctuations
2011
In this review we report on some experimental studies on the dynamics of Myoglobin in a confined geometry, obtained by encapsulation in a porous silica matrix, at low hydration levels. After formation through the solgel method, the samples were left aging/drying in order to reach a condition where only one or two water layers surround the proteins. In order to put in evidence the specific effect of confinement in the silica host, we compared this system with another one (i.e. hydrated powder) where proteins are confined by other proteins. Using elastic neutron scattering we investigate the temperature dependence of the mean square displacements of non-exchangeable hydrogen atoms of sol-gel …
Studies on the interaction of C1q,a subcomponent of the first component of complement, with porins fromSalmonella minnesotaincorporated into artifici…
1990
AbstractPurified outer membrane proteins (OMP) of Salmonella minnesota, Re-form, were incorporated into liposomes. These induced in macrophages a chemiluminescence signal identical to that of the intact Re-form. This signal was abolished by preincubation of porin-containing liposomes with purified C1q. Incorporation of isolated OMP into black lipid membranes (BLM) resulted in channel-formation which could not be inhibited by isolated C1q. Additionally, incubation of OMP-containing liposomes with BLM resulted in pore-formation within the BLM. This was amplified when lipid A was present within the liposomes. Preincubation of OMP-containing liposomes with purified C1q abolished pore-formation …
Thermoelectric Radiation Detector Based on Superconductor-Ferromagnet Systems
2017
We suggest an ultrasensitive detector of electromagnetic fields exploiting the giant thermoelectric effect recently found in superconductor-ferromagnet hybrid structures. Compared with other types of superconducting detectors where the detected signal is based on variations of the detector impedance, the thermoelectric detector has the advantage of requiring no external driving fields. This is especially relevant in multipixel detectors, where the number of bias lines and the heating induced by them are an issue. We propose different material combinations to implement the detector and provide a detailed analysis of its sensitivity and speed. In particular, we perform a proper noise analysis…