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Start Over Coverage 293-299

1. Convergence to equilibria in a differential equation with small delay

Creator:
Pituk, Mihály
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
delay differential equation, equilibrium, and convergence
Language:
English
Description:
Consider the delay differential equation (1) ˙x(t) = g(x(t), x(t − r)), where r > 0 is a constant and g : 2 → is Lipschitzian. It is shown that if r is small, then the solutions of (1) have the same convergence properties as the solutions of the ordinary differential equation obtained from (1) by ignoring the delay.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

2. Local disturbing potential model with the use of geophysical gravity data inversion case study in the area of Poland

Creator:
Trojanowicz, Marek
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
geodetic application of geophysical techniques, disturbing potential model, and local quasigeoid modelling
Language:
English
Description:
The presented paper investigates the local quasigeoid modelling based on the geophysical gravity data inversion (GGI method). The calculations performed indicate a very high accuracy of the derived quasieoid model which is developed when the modelling process is carried out using a global geopotential model. In this case, the local model of disturbing potential (model of type A) is in the form of , where is the part of the model containing the density model, is the polynomial part and is the part determined from a global model. If the global model is not included in the calculations (this is a type B model), the disturbing potential will be . The accuracy of the quasigeoid in latter model is significantly worse. Both types of models contain information about Earth’s crust density changes; however, only for the type B model we can expect that they correspond to real changes; whereas in the type A model the main information about density changes is contained in the part. So the type B model can be seen as a local, integrated model of both the external gravity field and the density distribution of the Earth's crust. Let us note that the GGI method is only used as a quasigeoid modelling method without geophysical or geological interpretation of the density model parameters. Regarding this, we can notice two problems related to the further development of the GGI method. The first concerns the relation of the GGI density model with geological information. The second problem refers to the possibility of increasing the accuracy of the type B quasigeoid model to the level of the A-type model. For the first problem, we demonstrate that the borders of density changes for the masses lying between the geoid and the Moho surface reflect the geological units surprisingly well. The test calculations relating to second problem, consist of determining the type B model using a certain initial model . There were three initial models adopted in the analysis. Results of the analysis indicates that this procedure increases the accuracy of the type B quasigeoid model, although the accuracy of the A-type model is still better.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

3. Methods of studying self-consistent models of flat systems

Creator:
Petrou, maria
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
space esearch, galacies, and flat systems
Language:
Czech
Description:
From the study of orbits and models of galaxies in recent years, it has become clear that Jeans' theorem is not adequate for building self-consistent models of real galaxies. The non-classical integrals play an important role in the dynamics of the system and their non-global nátuře must be taken into consideration. This work is about a new method for constructing self-consistent models of galaxies, where the distribution function is a function of the actions and the stochastic orbits are properly taken into account. It has been applied to the čase of constructing a self-consistent model of a non-rotating bar, and the way by which this method can be used to construct any sort of disk model is discussed.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

4. Role of irradiance in the chilling injury of young maize plants studied by chlorophyll fluorescence induction measurements

Creator:
Janda, T., Szalai, G., Kissimon, J., Páldi, E., Marton, C., and Szigeti, Z.
Format:
print
Type:
model:internalpart and TEXT
Language:
Multiple languages
Description:
During cold treatment of Zea mays L. plants there was a decrease in the level of Fv/Fm and in the quantum yield of photosynthetic electron transport. The degree of damage depended on the ambient temperature and on the irradiance (I). The lower the temperature and the higher the 1, the more pronounced damage occurred. This suggests that photoinhibition has an important role in the cold damage to young maize. Although there was no damage in complete darkness even at low temperature, the repair processes needed a normal temperature.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public