Sodium electrical resistivity

Commercial IX membranes have thicknesses of ca 0.15—0.5 mm and electrical resistances of ca 3-20 H-cm at 25°C when in equiUbrium with 0.5 W sodium chloride. The electrical resistances are somewhat higher in more dilute solutions because co-ions are more effectively excluded from the membrane by the IX resin. The electrical resistance decreases with increasing temperature at a rate of ca —1.9%/°C. The electrical resistance of an ED apparatus... 

This type, made by the General Electric Co., is resistant to sodium vapour and is used in sodiiun vapour discharge lamps. It has a very high boric oxide content, a low softening temperature, and a low electrical resistance. It is used as an internal layer in soda glass tubing X.8. ... 

CdSe, CdTe. CdSe films have been grown from complexed (with tartaric acid and triethanolamine) cadmium acetate or cadmium sulfate solutions and sodium selenosullale.1272 81 84 The films were amorphous or nanocrystalline with an average crystallite size of 6nm. The optical band gap was 1.8-2.1 eV, and the electrical resistivity was of the order 104-106Qcm. 

Grayish-white metal hody-centered cubic crystalline structure density 19.3 g/cm3 melts at 3,422°C vaporizes at 5,555°C vapor pressure 1 torr at 3,990°C electrical resistivity 5.5 microhm-cm at 20°C modulus of elasticity about 50 to 57 x lO psi (single crystal) Poisson s ratio 0.17 magnetic sus-ceptibilty +59 x 10-6 thermal neutron absorption cross section 19.2 + 1.0 barns (2,200m/sec) velocity of sound, about 13,000 ft/sec insoluble in water practically insoluble in most acids and alkabes dissolves slowly in hot concentrated nitric acid dissolves in saturated aqueous solution of sodium chlorate and basic solution of potassium ferricyanide also solubibzed by fusion with sodium hydroxide or sodium carbonate in the presence of potassium nitrate followed by treatment with water... 

Potassium and sodium are good conductors of heat.23 If the conductivity of silver be unity, that of sodium is 0 365. J. W. Hornbeck found the temp, coeff. of the thermal conductivity of potassium or sodium falls with rise of temp. The alkali metals are also good conductors of electricity 24 for example, the conductivity of sodium for heat and electricity is exceeded only by silver, copper, and gold. According to E. F. Northrup, the metals sodium, potassium, mercury, tin, lead, and bismuth have the same value for the ratio of the coeff. of electrical resistance to the coeff. of cubical expansion at the same temp. The electrical conductivity of lithium is nearly ll-4xl04 reciprocal ohms at 20°, that is, about 20 4 per cent, of the conductivity of hard silver of sodium at 2T 70, 22 4 XlO4 reciprocal ohms, that is, about 36 5 per cent, of the value of silver. 

Fig. 25.—Effect of Pressures on the Electrical Resistance of Solutions of Sodium Chloride.

When the calcium ion concentration is lowered in the fluids bathing nerve axons ifluids which are in very rapid equilibrium with the blood plasma) the electrical resistance ol the axon membrane is lowered, there is increased movement of sodium ions to ihe inside, and the ability ol ihe nerve to return io iis normal siale fallowing a discharge is slowed. Thus, on the one hand, there is hyperexcitabilily. Bui. the ability lor synaptic transmission is inhihited because the rate of acetylcholine liberation is a function ot ihe calcium ion concentration. The neuromuscular junction is... 

C. A. Kraus and W. W. Lucasse measured the electrical resistance of soln. of potassium and sodium in liquid ammonia. 

It is the presence of these tight junctions that occludes the aqueous paracellular diffusional pathway between the endothelial cells, and blocks the free diffusion of macromolecules, polar solutes, and ions from blood plasma into the ECF of the brain. It is this impediment to the movement of ions that results in the high in vivo electrical resistance of the BBB, of approximately 1800 fl cm2 [17]. This high electrical resistance or low conductance of the potential paracellular pathway emphasizes the extreme effectiveness of the tight junctions in occluding this pathway by effectively reducing the movement of ions. The radius of a sodium... 

This reaction gives high yield of carbon (44-80%) and can be easily scaled. Purifying of the raw material includes treatment of it with sodium carbonate solution with following treatment with acid. Surface area of nanocarbons obtained was 64-500 m2/g, specific electric resistance of powder 0.02-0.07 Ohm.cm. 

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