Magnetic Attenuation in Superconducting Cylinders by Beer-Lambert Modified Model

In this research, we study the magnetic attenuation of the superconducting cylinders by Beer-Lambert modified model. In optics, the Beer-Lambert model relates the absorption of light to the properties of the material through which the light is traveling. We modified Beer-Lambert model to describe behavior of magnetic field attenuation by superconducting cylinders. The penetrate field and London penetration depth are derived analytically. Finally, the attenuation of applied magnetic field is investigated and applied to cylindrical superconductors.

Canopy transmittance models for estimating forest leaf area index

Leaf area index was estimated in old-growth and young post-fire coniferous forests in northwestern Colorado. A line quantum sensor was used to measure canopy transmittance at different solar zenith angles. Leaf area indices were estimated from canopy transmittance data according to three different models and were subsequently compared with leaf area indices derived from existing allometric equations. Of the three canopy transmittance methods evaluated, a Beer–Lambert model adjusted for diffuse light and solar zenith angle was in closest agreement with allometric leaf area index estimates (11.5% average difference), followed closely by the Beer–Lambert model (14.4% average difference). Leaf area index predicted by a one-dimensional inversion model did not agree well with allometric estimates (30.6% average difference). Differences in methods of data processing were found to have significant effects on final results. Subtraction of diffuse photosynthetically active radiation increased the leaf area indices. Calculation of leaf area index at each sampled point and determination of a final mean leaf area index approximated the allometrically derived values more closely than did derivation of leaf area index only once from an averaged gap-fraction value. Leaf area index estimates varied with sun angle.