Relation Between Color Index and Effective Wave Length from the Observations of Hertzsprung and Vanderlinden.

Herbicidal activity of foliar-applied oxyfluorfen [2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene] was light dependent in buckwheat (Fagopyrum esculentumMoench. ‘Tokyo’). Plants were not injured when placed in the dark for as long as 4 days after herbicide treatment. When these plants were brought to the light, injury occurred, albeit more slowly than when plants were placed in the light immediately after treatment. The rate of injury increased as light intensity increased. The most effective wave length was 565 to 615ηm, suggesting the involvement of a pigment with its absorption spectrum in this region. Chlorophyll content was not reduced by oxyfluorfen. Preliminary evidence suggests that photosynthesis was affected only after membrane integrity was disrupted.

Download Full-text

On the Determination of the Colour-equivalent of a Star, with special reference to the Effective Wave-length and its Relation to Spectral Class: A Review of the Different Methods

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/82.9.495 ◽

1922 ◽

Vol 82 (9) ◽

pp. 495-510

Author(s):

K. Lundmark ◽

W. J. Luyten

Keyword(s):

Special Reference ◽

Wave Length ◽

Class A ◽

Spectral Class ◽

Effective Wave

Download Full-text

Absorption of radium (B+C) gamma-rays

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1945.0007 ◽

1945 ◽

Vol 183 (994) ◽

pp. 338-355 ◽

Cited By ~ 3

Keyword(s):

Gamma Rays ◽

Electron Pair ◽

Gamma Ray ◽

Wave Length ◽

Photoelectric Effect ◽

Pair Formation ◽

Photoelectric Absorption ◽

Absorption Coefficients ◽

Length Range ◽

Effective Wave

New measurements of the absorption of filtered gamma-rays from radium (B + C) in aluminium, carbon and lead have been made. A small condenser type of ionization chamber has been used, which overcomes many of the difficulties usually inherent in this kind of measurement. Detailed consideration has been given to the corrections which must be applied to ionization measurements before absorption coefficients can be calculated. From the most recent theories of absolution by scattering, photoelectric effect, and electron pair formation, total absorption coefficients for lead over the wave-length range concerned have been calculated. The problem of the effective wave-length of a filtered heterogeneous gamma-ray beam is discussed in some detail, and a proposed method of estimation put forward. Comparison of the calculations of µ / ρ with the experimental figures indicates that the photoelectric absorption rises more rapidly with increasing wave-length than is predicted by theory.

Download Full-text

Quantitative X-Ray Fluorescence Analysis With Variable Take-Off Angle

Advances in X-ray Analysis ◽

10.1154/s0376030800011290 ◽

1969 ◽

Vol 13 ◽

pp. 68-79

Author(s):

H. Ebel

Keyword(s):

Unit Area ◽

Wave Length ◽

Fluorescence Analysis ◽

Sample Surface ◽

Primary Radiation ◽

Absorption Coefficients ◽

X Ray ◽

Fluorescence Radiation ◽

Effective Wave ◽

Simple Evaluation

A solution of the intensity equation of X-ray Fluorescence analysis is possible either by the assumption of an effective wave length or by a variation of the take-off angle. When the intensity of the fluorescence radiation is measured as a function of the take-off angle, the extrapolation of this curve against take-off parallel to the flat sample surface offers a simple evaluation of the intensity equation. Since the influence of the secondary excitation is also taken in to account the composition and the mass per unit area of samples can be investigated as well as mass absorption coefficients and mean wavelengths of the polychromatic primary radiation.

Download Full-text