Free-space permeability

Flux density is calculated as the permeability of free space times the sum of the magnetic-field intensity and the induced magnetization... 

Other SI electrical units are determined from the first four via the fundamental constants eo and tiQ, the permittivity and permeability of free space respectively. The ampere is defined in terms of the force between two straight parallel infinitely long conductors placed a metre apart, and once this has been defined the coulomb must be such that one coulomb per second passes along a conductor if it is carrying a current of one ampere. 

The permeability (p) is a property of the material surrounding the conductor. The permeability of free space (p ) is... 

The ratio of the permeability of any material to the permeability of free space is termed the relative permeability (p ). 

Because the matrix has permeable characteristics, the ability of the molecules to diffuse will depend on the pore size of the permeable polymer and the available free space in the pores. Obviously, larger molecules would not be able to penetrate the matrix and complex with the NIR dye. As the amount of the dye-analyte complexes increase, the amount of free space into which other analytes can diffuse decreases. Therefore, a relation of the mobility with free space is defined as... 

In an effort to optimize the solvent-containing passive sampler design, Zabik (1988) and Huckins (1988) evaluated the organic contaminant permeability and solvent compatibility of several candidate nonporous polymeric membranes (Huckins et al., 2002a). The membranes included LDPE, polypropylene (PP), polyvinyl chloride, polyacetate, and silicone, specifically medical grade silicone (silastic). Solvents used were hexane, ethyl acetate, dichloromethane, isooctane, etc. With the exception of silastic, membranes were <120- um thick. Because silicone has the greatest free volume of all the nonporous polymers, thicker membranes were used. Although there are a number of definitions of polymer free volume based on various mathematical treatments of the diffusion process, free volume can be viewed as the free space within the polymer matrix available for solute diffusion. 

Salt Transport. The effects of ozone on membrane permeability can also be assessed by estimating salt leakage from treated tissue. In one study, susceptible bean plants were allowed to take up RbCl for 24 hr prior to ozone exposure. After exposure, leaf discs were placed in a desorption solution containing 0.5 M CaSOi and 2 mM KCl and the rate of Rb leakage into the desorption solution was determined. The initial loss was indistinguishable between treated and untreated plants and we assume that it represented exchange from free space. Then, for an extended period, treated tissue exhibited a linear loss of... 

A magnetic field produces lines of force that penetrate the medium to which the field is applied. These lines of force appear, for example, when you scatter iron filings on a piece of paper covering a bar magnet. The density of these lines of force is known as the magnetic flux density. In a vacuum, the magnetic field and the magnetic flux density are related by the permeability of free space, po-... 

Polypeptides obtained by the anionic polymerization of optically active N-carboxy-a-amino acid anhydrides are apt to have such an ordered structures as a-helices, which is useful for investigation on the relationship between the physical structure and the permeability of the membrane. Takizawa et al.44 46) studied the water permeation and solute separation through poly(n-alkyl L-glutamate) membranes 3. It was concluded that water molecules permeate through relatively large free spaces... 

The ratio of the magnetic moment of a magnetized body to its volume, expressed by the equation B = /z<)(H + 4jtM. where /tM is ihe permeability of free space. B is magnetic induction. H is (he exiemal... 

To consider the application of microwave irradiation for organic synthesis, the first step is to analyze the reaction components together with their dielectric properties among which of the greatest importance is dielectric constant (cr) sometimes called electric permeability. Dielectric constant (er) is defined as the ratio of the electric permeability of the material to the electric permeability of free space (i.e., vacuum) and its value can derived from a simplified capacitor model (Fig. 1.4). 

The summation is over the unpaired electrons which have spherical polar coordinates r, and and //0 is the permeability of free space. The angular averages over a 3d... 

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