Showing papers on "Conductance published in 1974"
TL;DR: The use of the voltage clamp technique is reported to compare the reversal potentials of the conductance increase produced by the excitatory transmitter and the application of L-glutamate at the insect neuromuscular junction.
Abstract: THERE is considerable evidence that L-glutamate is the excitatory transmitter both at the insect and crustacean neuromuscular junction1,2, and also in the vertebrate central nervous system3. Here we report the use of the voltage clamp technique to compare the reversal potentials of the conductance increase produced by the excitatory transmitter and the application of L-glutamate at the insect neuromuscular junction. We also investigated the ionic basis of the L-glutamate conductance increase using voltage clamping. These experiments could be carried out accurately because changes in resistance of the electrically excitable membrane caused by changes in membrane potential or by different ionic media do not affect the amplitude of the excitatory junctional currents or glutamate currents.
73 citations
TL;DR: A model incorporating the above properties of the EIM channels predicts the observed voltage dependence of ionic conductance and conductance relaxation time, which are also characteristic of natural electrically excitable membranes.
Abstract: The kinetics of the opening and closing of individual ion-conducting channels in lipid bilayers doped with small amounts of excitability-inducing material (EIM) are determined from discrete fluctuations in ionic current. The kinetics for the approach to steady-state conductance during voltage clamp are determined for lipid bilayers containing many EIM channels. The two sets of measurements are found to be consistent, verifying that the voltage-dependent conductance of the many-channel EIM system arises from the opening and closing of individual EIM channels. The opening and closing of the channels are Poisson processes. Transition rates for these processes vary exponentially with applied potential, implying that the energy difference between the open and closed states of an EIM channel is linearly proportional to the transmembrane electric field. A model incorporating the above properties of the EIM channels predicts the observed voltage dependence of ionic conductance and conductance relaxation time, which are also characteristic of natural electrically excitable membranes.
72 citations
TL;DR: The time and potential dependence of the conductance process (es) underlying the longlasting afterhyperpolarization (AHP) in the cat's a-motoneurones were studied and it was concluded that the AHP in mot oneurones is given by a potassium Conductance process with this complex S-shaped time course.
Abstract: The time and potential dependence of the conductance process (es) underlying the longlasting afterhyperpolarization (AHP) in the cat's a-motoneurones were studied. The conductance changes were determined by injection of short current pulses. The conductance time course was characterized by a longlasting exponential decay interrupted by a plateau corresponding to the slower hypcrpolarizing phase of the AHP. By displacing the membrane potential in the subthreshold region with the injection of longlasting current pulses it was found that the conductance was largely unaffected by membrane potential displacements. Similar characteristics were found when calculating the AHP conductance time course from the AHP voltage. It was concluded that the AHP in motoneurones is given by a potassium conductance process with this complex S-shaped time course. A mathematical expression describing this time course is given.
64 citations
TL;DR: By two independent techniques the transepithelial shunt contributes only 1/5 of the conductance of Necturus fundic gastric mucosa, which is a mucosa composed of two highly coupled cell types.
Abstract: Necturus fundic gastric mucosa was studied to define the magnitude of cellular and shunt conductance. Electrotonic coupling of surface epithelial cells by a low resistance pathway was shown by analysis of current spread within the epithelial sheet. From this analysis cellular conductance was found to be 4.18 ± 1.57 × 10−4 Ω−1 cm−2, and transepithelial shunt conductance was 1.1 × 10−4 Ω−1 cm−2. The ratio of cell-to-shunt conductance was 3.80. These results are confirmed by a second technique in which the Δp. d. across the serosal membrane of surface cells was compared to the transepithelial Δp. d. resulting from a Δ[K+] in the serosal solution. The data were analyzed using an electrical circuit equivalent to a mucosa composed of two highly coupled cell types. By this technique cell conductance was 3.07 × 10−4 Ω−1 cm−2, and transepithelial shunt conductance was 0.830 × 10−4 Ω−1 cm−2. The cell/shunt conductance ratio was 3.70. Thus, by two independent techniques the transepithelial shunt contributes only 1/5 of the conductance ofNecturus fundic gastric mucosa.
49 citations
TL;DR: The results indicate that the passive conductance pathway accounts for approximately 80% of the total tissue conductance and is cation-selective and the relative ionic permeabilities of this pathway, which is in all likelihood largely if not entirely extracellular, isPK≧PRb>PNa≫PCl.
Abstract: The unidirectional influxes of several monovalent ions into the epithelium ofin vitro rat jejunum were determined as a function of the transepithelial electrical potential difference using the technique described by Frizzell and Schultz (J. Gen. Physiol.
59:318, 1972). The results indicate that the passive conductance pathway accounts for approximately 80% of the total tissue conductance and is cation-selective. The relative ionic permeabilities of this pathway, which is in all likelihood largely if not entirely extracellular, isP
K≧P
Rb>P
Na≫P
Cl. The sequence of relative cation permeabilities corresponds most closely to Eisenman's sequence V suggesting that the route possesses a negative electrical field strength of intermediate intensity. The unidirectional influxes of lysine and tetraethylammonium (TEA) were unaffected over the range of ±50mV. These findings are consistent with the notion that the pasive conductance pathway is impermeable to solutes with an equivalent diameter greater than 8 A; however, the possibility that factors other than ionic size are responsible for the exclusion of TEA and lysine from the shunt pathway cannot be excluded. The diffusional influx of Na closely agrees with the transepithelial serosa-to-mucosa flux of Na suggesting that the latter is largely, if not entirely, mediated by the passive conductance pathway and may circumvent the limiting membranes of the epithelial cells.
40 citations
TL;DR: Properties of anion permeation through the membrane of skeletal muscle fibres of the stingray, Taeniura lymma, were studied with intracellular recording and polarization techniques.
Abstract: 1. Properties of anion permeation through the membrane of skeletal muscle fibres of the stingray, Taeniura lymma, were studied with intracellular recording and polarization techniques.
2. The Cl conductance of the resting membrane in the normal stingray saline at pH 7·7 is 8–10 times greater than the K conductance.
3. The Cl conductance decreases with decreasing external pH, with an apparent pK of 5·3, whereas the K conductance is independent of pH between 4 and 9.
4. The Q10 of the Cl conductance is about 2·0, compared with a value of 1·2–1·4 for the K conductance.
5. The Cl conductance is proportional to the external Cl concentration when observed after the fibre is equilibrated in the test solution.
6. The permeability sequence obtained by potential measurement is SCN > NO3 > Cl = Br > I > ClO3 and the permeability ratio is independent of the mole fraction of anions.
7. The conductance sequence determined by total replacement of the external Cl with other anion species differs from the permeability sequence and the conductance observed for partial replacement deviates significantly from that expected from the independence principle.
8. Possible mechanisms of anion permeation are discussed.
39 citations
TL;DR: The actual mechanism of lipid bilayer conductivity in the presence of tetrachlorotrifluoromethylbenzimidazole (TTFB) is determined and it is shown that the T2H− is not formed in aqueous phase but rather within the membrane, which does not explain the high current values obtained.
Abstract: The purpose of the work presented in this paper was to determine experimentally the actual mechanism of lipid bilayer conductivity in the presence of tetrachlorotrifluoromethylbenzimidazole (TTFB). The capacitance and conductance of lipid bilayers were measured with a current-clamp method, as a function of equal TTFB concentrations (10−7 to 5×10−5m) in the two aqueous phases. The voltage across the membrane was measured as a function of time during rectangular current pulses. If the hydrogen buffer capacity of the solution is low, the voltage response to long current pulses has two components. The slow component is due to hydrogen ion concentration changes in the unstirred layers. This component disappears if the buffer capacity is made high enough. Membrane capacitance and conductance can be determined from the fast component of the voltage response. The conductance increases with the square of TTFB concentration (pH 2 to 7) and the capacitance is 0.4 μF/cm2 for the range of concentration used. If solutions of low buffer capacity are used, shifts of hydrogen ion concentrations near the membrane give rise to a complicated dependence of the membrane potential on pH given a unit pH difference between the two aqueous solutions (protonic potential). This dependence can be explained if the membrane permeability for neutral uncoupler molecules (TH) is high enough. The membrane permeability coefficient is determined:PTH=10 cm/sec. In other experiments the dependence of short-circuit current on pH difference between the two solutions was also measured, with the pH value on one side fixed in a given experiment. These complicated nonmonotonic dependences can be described using a mathematical equation with only two parameters: (1) the dissociation constant of TTFB in water (pK=5.2), and (2) the proportionality factor between short-circuit current and TTFB concentration squared. These data can be formally interpreted to mean that the membrane is permeable only to T2H− and TH, where T is TTFB anion and H is hydrogen ion. However, this model does not explain the high current values obtained because of the limited rate constant of T2H− formation in aqueous solution. An alternative model is proposed. It is shown that the T2H− is not formed in aqueous phase but rather within the membrane. The T2H− can be the intramembrane charge carrier if its life-time is long enough. If the average life-time is short, current might be carried through the membrane by proton exchange between TH and T−, when they collide. This mechanism could also account for the action of uncouplers of oxidative phosphorylation other than TTFB.
37 citations
TL;DR: An experimental procedure is described for determining the six independent conductance coefficients that control the fluxes of ions and solvent in a system of a single salt and water through an ionic membrane and it is indicated that the postulate of local linear behaviour is obeyed.
Abstract: An experimental procedure is described for determining the six independent conductance coefficients that control the fluxes of ions and solvent in a system of a single salt and water through an ionic membrane. Some of the data required are electrical and have been published already. Additionally, measurements are needed on flows under a pressure gradient. A cell is described for measuring the volume and salt fluxes through the membrane in the pressure range up to 1 MN m -2 . Data are given at various concentrations up to 1 mol dm -3 , for NaBr, CsBr and SrBr 2 in the cation permeable membrane Zeo-Karb 315 at 25 oC. The calculation of the non-equilibrium thermodynamic conductance coefficients is described and their values tabulated. It is indicated that the postulate of local linear behaviour is obeyed for electrical potential and osmotic gradients. For pressure gradients, the filtration coefficients L p decreased by about 1% per atmosphere across a membrane 1.4 mm thick. This effect correlated reasonably well with the observed effect of pressure on the membrane thickness if an idealized capillary model was used to describe flow. The differential conductance coefficients are strong functions of solution concentration. This dependence effectively limits use of integral linear flux equations to extremely small concentration intervals across the membrane.
32 citations
TL;DR: In this article, a two dimensional adaptation of Motts formula using a localisation criterion close to theoretical estimates was used to estimate the minimum metallic conductance of a P channel MNOSFET.
29 citations
TL;DR: The crystal structure of 1,10-phenanthroline was determined and refined to an R-value of 0.051 in this article, where the coordination number and geometry were discussed in terms of 5coordinate tetragonal pyramidal and 4-coordinate square planar models.
Abstract: The crystal structure of cis-chlorobis(triethylphosphine)-1,10-phenanthrolineplatinum(II) fluoroborate has been determined and refined to an R-value of 0.051. The space group is P21/c and the cell dimensions are a = 0.9215(2), b = 1.1991(3), c = 2.6832(6) nm, β = 99.38(3)°, with 4 molecules per unit cell. The interatomic distances to Pt are: Pt—N(1), 213.7(19); Pt—N(2), 284.3(20); Pt—P(1), 223.9(7); Pt—P(2), 224.1(6); Pt—Cl, 236.1(6) pm.The coordination number and geometry is discussed in terms of 5-coordinate tetragonal pyramidal and 4-coordinate square planar models, the latter being regarded as the more acceptable.Monodentate o-phenanthroline is thus observed for the first time in the solid state. The structure of the complex in solution is discussed with the aid of conductance and nuclear magnetic resonance results which suggest the possibility of a novel fluxional system.
28 citations
TL;DR: Oxidized cholesterol lipid films were studied under voltage clamp conditions and went into a transition from a stable, relatively noise-free-current state to a gradually increasing current with a large noise component that generally signalled imminent breakdown but the membrane could spontaneously revert to the original high-resistance, low-noise state.
Abstract: Oxidized cholesterol lipid films were studied under voltage clamp conditions. Certain kinds of conductance phenomena closely resembling effects described in the literature and atributed to various additives were observed with unmodified lipid films. These include spontaneous conductance changes, multilevel conductance states and negative resistance phenomena in films formed from aged oxidized cholesterol-inhydrocarbon solutions. The multilevel conductance state manifests itself in the form of step changes in current under voltage clamp, the magnitudes of which correspond to conductance intervals of 5±2×10−10 mho and its multiples in 0.1n sodium chloride. These steps are attributed to channels that form in the film. Under certain conditions it has been observed that the action of the electric field was to close channels that were open at lower voltages. Under these conditions the current-voltage plot shows a distinct region of “negative differential” resistance. Films generated from freshly prepared oxidized cholesterol solutions did not exhibit multistable phenomena but under a prolonged voltage clamp the membrane conductance went into a transition from a stable, relatively noise-free-current state to a gradually increasing current with a large noise component. This sequence generally signalled imminent breakdown but the membrane could spontaneously revert to the original high-resistance, low-noise state. These kinds of intrinsic behavior sufficiently resemble certain effects produced by additives to merit special consideration during membrane reconstitution experiments.
TL;DR: In this article, conductance measurements are reported for potassiumm-benzenedisulfonate and ferricyanide, for calcium, strontium, barium, and manganese chloride, and for manganized and potassium sulfate in D2O at 25°C.
Abstract: Precise conductance measurements are reported for potassiumm-benzenedisulfonate and ferricyanide, for calcium, strontium, barium, and manganese chloride, and for manganese and potassium sulfate in D2O at 25°C. Measurements were also carried out in water at 10 and 25°C for all the salts with the exception of K3Fe(CN)6 at 10°C. Two runs are reported for sodium sulfate in water at 25°C. Limiting conductances of these ions are discussed in terms of solvent structural effects. The association constant for MnSO4 is found to be the same in H2O and D2O.
TL;DR: The membrane capacitance and slope conductance of sheep cardiac Purkinje tissue were examined under conditions of constant and slowly changing voltage within the potential range: −70 to −100 mV.
Abstract: 1. The membrane capacitance and slope conductance of sheep cardiac Purkinje tissue were examined under conditions of constant and slowly changing voltage within the potential range: -70 to -100 mV. Data were secured by applying constant current pulses, or by imposing ramp commands or small changes in holding potential under voltage clamp control.2. The electrical measurements, combined with light and electron microscopic data on preparation structure, were interpreted with the aid of a core-conductor model that permits quantitative representation of cleft- and lateral surface membranes for individual preparations (Hellam & Studt, 1974).3. The analysis led to the following conclusions. The slope conductance of unit membrane area (G(m)) is quite low in the normal resting potential range; at -80 mV the value is 0.09 mmho/cm(2). G(m) exhibits a marked decline with depolarization in the region positive to -88 mV, but only slight voltage-dependence at more negative potentials within the range of present observations. The capacitance of unit membrane area (C(m)), from voltage ramp data collected near -90 mV, is 0.9 muF/cm(2).4. Comparison with results of earlier studies indicates that the differences between present and previous experimental estimates of these membrane characteristics result from differences in modelling and structural analysis of tissue preparations.
TL;DR: In this paper, the electrical conductivity of the isobutyric acid + water critical system has been measured using a hybrid conductance/viscosity cell, a modified Ubbelhode viscometer, which allows almost simultaneous measurements of viscosity and conductance.
Abstract: The electrical conductivity of the isobutyric acid + water critical system has been measured for several concentrations including the critical. Measurements were made using a hybrid conductance/viscosity cell‐a modified Ubbelhode viscometer‐which permitted almost simultaneous measurements of viscosity and conductance. Absence of a conductivity anomaly was verified for T – Tc ≥ 0.03°C. The results of additional measurements made on a critical solution in which 2% of the protons were replaced by K+ ions clearly show that the absence of an anomaly is not simply due to the fact that, in this binary system, most of the current is carried by the proton. The possibility of an anomaly in the ac conductance quite unrelated to the viscosity anomaly and strongly dependent on bridge frequency, occurring (for audio frequencies) at smaller T – Tc values than those reached in this work, is discussed.
TL;DR: In this paper, a four-electrode cell was used to determine the d.c. conductance with a reasonable accuracy, provided that the resistance is less than several kiloohms.
TL;DR: The change in conductance of an amorphous silicon film due to a transverse electric field was observed in this article, where the films were electron-beam vacuum deposited at controlled rates of less than 5 A/sec onto Si-SiO2 substrates and then annealed for 4 h at 400 °C.
Abstract: The change in conductance of an amorphous silicon film due to a transverse electric field was observed. The films were electron‐beam vacuum deposited at controlled rates of less than 5 A/sec onto Si–SiO2 substrates and then annealed for 4 h at 400 °C. The results indicate that the Fermi level is not pinned at near midgap and that the localized states are nearly uniform over a 0.4‐eV section above and 0.4 eV below the Fermi level near the middle of the energy gap. Calculations show the density of localized states to be 1020/eV cm3 over this region and to be reduced as the deposition rate decreases.
TL;DR: A proteolipidic toxin, prymnesin, when added to the aqueous solutions around thin lipid membranes causes a marked increase in membrane conductance, which is inversely proportional to temperature, and the toxin-treated membrane is cation-permselective.
Abstract: A proteolipidic toxin, prymnesin, when added to the aqueous solutions around thin lipid membranes causes a marked increase in membrane conductance. The toxin-treated membrane is cation-permselective. The extent of cation permselectivity is dependent upon ionic strength of the aqueous solutions in a fashion similar to the dependence of cation permselectivity of a cation exchanger containing about 100mm of fixed negative sites. Dose-response relationship studies reveal a linear relation between log prymnesin concentration and log membrane conductance. The slope of the curve is around 3 if the toxin is applied to one side of the membrane and is around 7 if the toxin is applied to both sides of the membrane. The membrane treated with toxin on one side only is clearly asymmetric in its properties. These characteristics are expressed by an asymmetric current-voltage relationship, and by asymmetric sensitivity of membrane conductance to pH and to salt concentration. The conductance of the toxin-treated membrane is inversely proportional to temperature. It is suggested that aggregates of toxin moieties assemble in the membrane to form negatively charged aqueous pores. There is roughly a good correlation between the increase in membrane conductance and the increase in membrane permeability to urea if both were attributed to the formation of aqueous channels in the membrane.
TL;DR: In this article, Lanthanide chloride and isothiocyanate adducts of tetramethylmalonamide of compositions LnCl3. 2TMMA (Ln = LaLu, Y, except Pm and Tm), Ln(NCS)3. 3TMMA(Ln.
TL;DR: In this paper, the conductance of potassium perchlorate in mixtures of ethylene carbonate and acetonitrile covering the range 82.6 ≥ D ≥ 36.0 in dielectric constant has been measured.
Abstract: The conductance of potassium perchlorate in mixtures of ethylene carbonate and acetonitrile covering the range 82.6 ≥ D ≥ 36.0 in dielectric constant has been measured. The Walden products in these aprotic solvents are approximately one-half as large as the products for the same salt in isodielectric mixtures of water and tetramethylene sulfone. This alters the distribution between electrostatic and hydrodynamic terms in the theoretical conductance function in such a way that the calculated association constants for potassium perchlorate are much smaller in the aprotic mixtures.
TL;DR: It is shown that the conductance of the open configuration has a temperature dependence that is just that expected from the temperature dependence of the bathing electrolyte.
TL;DR: In this article, the change of electrical conductance of alkali metal solutions in hexamethylphosphoramide (HMPA) on freezing has been studied and a value of approximately 80 cm3 for the apparent molal volume of the solvated electron has been deduced.
Abstract: The dissolution of alkali metals in hexamethylphosphoramide (HMPA) causes a decrease in density and a value of approximately 80 cm3 for the apparent molal volume of the solvated electron has been deduced. The change of electrical conductance of alkali metal solutions in HMPA on freezing has been studied. Surprisingly, while the conductance of sodium solutions falls almost to zero on freezing, that of lithium solutions increases by a factor of about one hundred. The solid lithium solutions have a peak conductance at about –19°C; possible reasons for this behaviour are discussed. Thermionic- and photo-emission of electrons have also been measured. The dependence of thermionic current on concentration is unexpected; for both lithium and sodium solutions there is a pronounced maximum at concentrations of about 10–3 mol dm–3 and the current decreases to about 1/40 of the peak value at a concentration of 0.4 mol dm–3. The thermionic emission energy has been calculated from the temperature dependence of the thermionic current, and is about 0.74 eV at c∼ 10–3 mol dm–3, and 0.98 eV at c∼ 0.4 mol dm–3. The threshold energy for photo-emission calculated from the long wavelength limit for photo-emission from a 0.4 mol dm–3 solution is 1.05 eV.
TL;DR: In this paper, the indirect moving boundary method was applied for the first time for the determination of the transference numbers in polyelectrolyte solutions, which seems to be more precise than other methods used for this purpose.
Abstract: The indirect moving boundary method was applied for the first time for the determination of the transference numbers in polyelectrolyte solutions. The method seems to be more precise than other methods used for this purpose. Conductance and transference measurements of solutions of sodium polystyrenesulphonate were made in the concentration range from 0.002 to 0.1 equiv./ dm3. The experimental results are discussed in the light of the theory of counterion association. Introduction
TL;DR: In this article, it was shown that three and only three parameters are sufficient to generate a function Λ (c; Λ0, KA, R) which reproduces observed equivalent conductance Λ as a function of concentration c within experimental error up to concentrations of about 2 × 10-7D3 eq/liter (D = dielectric constant).
Abstract: It is shown that three and only three parameters are sufficient to generate a function Λ (c; Λ0, KA, R) which reproduces observed equivalent conductance Λ as a function of concentration c within experimental error up to concentrations of about 2 × 10-7D3 eq/liter (D = dielectric constant). The three parameters are: Λ0, the limit of Λ(c) at zero concentration; KA, the association constant; and R, a distance. Realization that conductance data can provide only one distance parameter suggests a model for electrolytic solutions in which R is defined as the radius of the sphere inside of which a unique partner can be found for a paired ion, and outside of which continuum theory may be applied. All system-specific effects (ion-ion and ion-solvent interactions, and the inherent spatial discontinuity of real solutions) appear within the spheres of radius R centered at the cations of the ion pairs. The association constant therefore depends not only on electrostatic attraction but also on the multiplicity of molecular parameters that are needed to describe short range interactions.
TL;DR: In this article, the effect of doping with 3D transition elements on the conductance of Al/Al oxide/Al and Al oxide/Ag tunnel junctions has been investigated, and the effect is greater with the Al than the Ag functions.
Abstract: The author reports the effect of doping with 3d transition elements on the conductance of Al/Al oxide/Al and Al/Al oxide/Ag tunnel junctions The conductance-voltage characteristics have been measured as a function of concentration of dopant, temperature and magnetic field The doping lowers the conductance G(V=0) approximately linearly with concentration, and G(V) becomes 'vee' shaped over a wide voltage range and the sides of the 'vee' are steeper at higher concentrations These effects are greater with the Al than the Ag functions
TL;DR: In this paper, bias and temperature dependence of tunneling structure was studied in Zn-doped $p$-type GaAs Schottky-barrier junctions over a doping range of 5.4 \ifmmode\times\else\texttimes\fi{} ${10}^{18}$-1.4
Abstract: The bias and temperature dependence of tunneling structure was studied in Zn-doped $p$-type GaAs Schottky-barrier junctions over a doping range of 5.4 \ifmmode\times\else\texttimes\fi{} ${10}^{18}$-1.4 \ifmmode\times\else\texttimes\fi{} ${10}^{19}$ Zn/${\mathrm{cm}}^{3}$. An increase in conductance with increasing temperature at the bias polarity for electron injection into the semiconductor is considered to be a consequence of impurity-assisted (two-step) tunneling via acceptor impurities. The reduction in the lifetime of electrons localized on acceptor sites by stimulated emission in a thermally populated phonon field is responsible for the temperature dependence. An enhancement of phonon-induced structure in the tunneling characteristics by Ar-ion bombardment of the semiconductor surface is observed. The magnitude of the zero-bias conductance minimum is found to vary as the logarithm of both bias voltage and temperature of higher biases and temperature, but to saturate at low values of these parameters. The magnitude of the conductance minimum depends strongly upon doping, but its functional dependence upon bias and temperature varies only slightly over the doping range investigated. These results and the observations of others are the basis for objections to the major models dealing with the conductance minimum. The strong correlation between the magnitude of the conductance minimum and impurity-band localization observed by others and the similarity of the bias and temperature dependence of the conductance minimum to that of the Appelbaum conductance maximum suggest the possibility of some form of exchange interaction as the cause of the conductance minimum.
TL;DR: In this paper, the Kapitza conductance of annealed and electropolished silver samples between 1 and 2 K was measured and the lowest results were reduced by about a factor of 5 with respect to those reported by other investigators.
TL;DR: The analysis of the dependence of the limiting equivalent conductance viscosity product on chain length of alcohol molecules shows that λ°H+η increases with increasing monomer concentration.
Abstract: Conductance measurements at 25°C on dilute solutions of hydrochloric acid in pentan-1-ol containing small amounts of water are reported. The data were analyzed with the 1965 Fuoss–Onsager conductance equation.The analysis of the dependence of the limiting equivalent conductance viscosity product on chain length of alcohol molecules shows that λ°H+η increases with increasing monomer concentration.This experimental evidence is qualitatively discussed with respect to current theories of the proton-transfer mechanism.
TL;DR: In this article, a model was proposed where the tunneling rate is stimulated whenever the relaxation and recombination phonon frequencies equal, and the most probable explanation seems to be a model where the tunability of electrons is very thickness dependent and the amplitude goes to zero within a narrow temperature range.
Abstract: Additional structure is seen in conductance versus voltage curves when electrons are tunneled into very thin superconducting films. This peak like structure has been detected in several materials; it is observed at multiples of the energy gap above the main conductance maximum. The peak amplitude is very thickness dependent. At roughly half the transition temperature of the ultrathin film the amplitude goes to zero within a narrow temperature range. Effects of magnetic field, an overlay of a non-superconductor, and annealing are less pronounced. The most probable explanation seems to be a model where the tunneling rate is stimulated whenever the relaxation and recombination phonon frequencies equal.
TL;DR: The conductances of aqueous solutions of the above compounds have been measured in the range of ionic strength between 5×10−4−10−1 at 25°C.
Abstract: The conductances of aqueous solutions of the above-mentioned compounds have been measured in the range of ionic strength between 5×10−4–10−1 at 25°C The decrease in equivalent conductance due to the increase in concentration always becomes smaller with increasing molecular weight of the tetraalkylammonium ions K4Fe(CN)6 is comparable to (Me4N)4Fe(CN)6, K4Mo(CN)6 is intermediate between the tetraethyl- and the tetra-n-propylammonium salts, and K3Co(CN)6 has a conductance larger than the tetra-n-butylammonium salt These results are compared with the kinetic salt effects due to the tetraalkylammonium ions