Search results
Results from the WOW.Com Content Network
The correlation should, however, be treated with caution. For instance, dichloromethane has a value of ε r of 9.08 (20 °C) and is rather poorly soluble in water (13 g/L or 9.8 mL/L at 20 °C); at the same time, tetrahydrofuran has its ε r = 7.52 at 22 °C, but it is completely miscible with water
Typical R-values are given for various materials and structures as approximations based on the average of available figures and are sorted by lowest value. R-value at 1 m gives R-values normalised to a 1 metre (3 ft 3 in) thickness and sorts by median value of the range.
The R-value is the building industry term [3] for thermal resistance "per unit area." [4] It is sometimes denoted RSI-value if the SI units are used. [5] An R-value can be given for a material (e.g. for polyethylene foam), or for an assembly of materials (e.g. a wall or a window). In the case of materials, it is often expressed in terms of R ...
Permittivity as a function of frequency can take on real or complex values. In SI units, permittivity is measured in farads per meter (F/m or A 2 ·s 4 ·kg −1 ·m −3 ). The displacement field D is measured in units of coulombs per square meter (C/m 2 ), while the electric field E is measured in volts per meter (V/m).
The construction industry makes use of measures such as the R-value (resistance) and the U-value (transmittance or conductance). Although related to the thermal conductivity of a material used in an insulation product or assembly, R- and U-values are measured per unit area, and depend on the specified thickness of the product or assembly. [note 2]
Thermal insulance (R-value) is a measure of a material's resistance to the heat current. It quantifies how effectively a material can resist the transfer of heat through conduction, convection, and radiation.
Higashi anomalies: The very high c values that are labeled as thermal conductivities in table III on page 100 would roughly fit the thesis of the paper if they came with lower orders of magnitude. The way that the dry soils get a lot lighter between Table I on page 99 and table IV on pages 102-3 is eventually explained by the fact that Table I ...
Some representative refractive indices; Name of material λ (nm) Refractive index no. n Reference Vacuum: 1 (by definition) Air at STP: 1.000273 [citation needed]Gases at 0 °C and 1 atm