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Start Over Coverage 149-161

1. Oscillatory and asymptotic behavior of solutions of higher order damped nonlinear difference equations

Creator:
Thandapani, E., Ethiraju and Arul, R.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
math, higher order difference equation, and oscillation
Language:
English
Description:
The asymptotic and oscillatory behavior of solutions of mth order damped nonlinear difference equation of the form \[ \Delta (a_n \Delta ^{m-1} y_n) + p_n \Delta ^{m-1} y_n + q_n f(y_{\sigma (n+m-1)}) = 0 \] where $m$ is even, is studied. Examples are included to illustrate the results.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

2. Thermal dissipation during photosynthetic induction and subsequent dark recovery as measured by photoacoustic signals

Creator:
Buschmann, C.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
chlorophyll fluorescence, energy balance, heat production, induction kinetics, and photoacoustic spectroscopy
Language:
Multiple languages
Description:
The thermal photoacoustic signal (279 Hz) and the chlorophyll (Chl) fluorescence of radish cotyledons (Raphanus sativus L.) were measured simultaneously. The signals were recorded during a photosynthetic induction with actinic radiation of different quantum fluence rates [20, 200, and 1200 µmol(PAR-quantum) m-2 s-1]. The rise of these signals upon irradiation saturating photosynthesis was followed in the steady state of the induction and during the subsequent dark-recovery (i.e., in dark periods of 1, 5, 15, and 45 min after the induction). From these values various parameters (e.g., quantum yield, photochemical loss, different types of quenching coefficients) were calculated. The results show that heat dissipation detected by photoacoustic measurements is neither low, constant, nor always parallel to Chl fluorescence. Therefore, the thermal signal should always be measured in order to fully understand the way leaves convert energy taken up by PAR absorption. This helps in the interpretation of photosynthesis under different natural and anthropogenic conditions (stress and damage effects).
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public