Different atmospheric effects causing FSO link attenuation: experimental results and modelling in Czech Republic

2015 ◽  
Author(s):  
Ondrej Fiser ◽  
Vladimir Brazda ◽  
Otakar Wilfert
2000 ◽  
Author(s):  
Anton Kohnle ◽  
Ruland Neuwirth ◽  
Karin Stein ◽  
Karin Weiss-Wrana

2021 ◽  
Vol 3 ◽  
pp. 1-6
Author(s):  
Stanislav Popelka ◽  
Alena Vondrakova ◽  
Marketa Beitlova ◽  
Stanislava Drahosova

Abstract. The usage of road atlases is experiencing a decline due to the rise in popularity of modern GPS navigational systems. However, road atlases are still utilised by some individuals, both in combination with mobile navigation and separately when navigating during the trip. Therefore, road atlases continue to be published. They are regularly updated, and they do gradually change, such as when the map symbology changes or when the creation of maps takes new technological possibilities into account. The changes in map symbology are the main essence of the presented paper. Based on the assumption presented by an expert (head of the largest cartographic publishing house in the Czech Republic) during an expert discussion that the 20-year-old road atlas is easier to read and that the required information was more quickly accessible in the old atlas than in the new atlas, a scientific experiment was designed and performed. Within the comparison of the "old" and "new" atlases, three hypotheses were established: (1) Accuracy of responses will be higher for the "old" atlas, (2) Time for task completion will be lower for the "old" atlas, and (3) Orientation in the maps from the "old" atlas will be easier. The eye-tracking testing performed did not confirm the first hypothesis, but the statistics confirmed the second and third hypotheses. The reasons for the different results for the "old" and "new" atlases were sometimes obvious (change in the graphic variables of a particular map symbol). Still, other times the causes were not completely clear. All of the experimental results were provided to the publishing house for further use in practice.


2012 ◽  
Vol 66 (12) ◽  
Author(s):  
Jiří Kaláb ◽  
Zdeněk Palatý

AbstractBatch electrodialysis of aqueous solutions of oxalic acid was investigated using a laboratory electrodialyzer ED-Z mini equipped with ion-exchange membranes Ralex-AMH-PES and Ralex-CMHPES (Mega, Stráž pod Ralskem, Czech Republic). The paper presents a mathematical model which enables to predict changes in the oxalic acid concentrations in the diluate and concentrate compartments during the electrodialysis process under various conditions specified by combinations of the initial acid concentrations with current densities. The calculation proved a good agreement between the developed model and the experimental results.


2009 ◽  
Vol 96 (14) ◽  
pp. 26-35
Author(s):  
Jan Valentin ◽  
Petr Mondschein

1988 ◽  
Vol 102 ◽  
pp. 357-360
Author(s):  
J.C. Gauthier ◽  
J.P. Geindre ◽  
P. Monier ◽  
C. Chenais-Popovics ◽  
N. Tragin ◽  
...  

AbstractIn order to achieve a nickel-like X ray laser scheme we need a tool to determine the parameters which characterise the high-Z plasma. The aim of this work is to study gold laser plasmas and to compare experimental results to a collisional-radiative model which describes nickel-like ions. The electronic temperature and density are measured by the emission of an aluminium tracer. They are compared to the predictions of the nickel-like model for pure gold. The results show that the density and temperature can be estimated in a pure gold plasma.


Author(s):  
Y. Harada ◽  
T. Goto ◽  
H. Koike ◽  
T. Someya

Since phase contrasts of STEM images, that is, Fresnel diffraction fringes or lattice images, manifest themselves in field emission scanning microscopy, the mechanism for image formation in the STEM mode has been investigated and compared with that in CTEM mode, resulting in the theory of reciprocity. It reveals that contrast in STEM images exhibits the same properties as contrast in CTEM images. However, it appears that the validity of the reciprocity theory, especially on the details of phase contrast, has not yet been fully proven by the experiments. In this work, we shall investigate the phase contrast images obtained in both the STEM and CTEM modes of a field emission microscope (100kV), and evaluate the validity of the reciprocity theory by comparing the experimental results.


Author(s):  
A. Ourmazd ◽  
G.R. Booker ◽  
C.J. Humphreys

A (111) phosphorus-doped Si specimen, thinned to give a TEM foil of thickness ∼ 150nm, contained a dislocation network lying on the (111) plane. The dislocation lines were along the three <211> directions and their total Burgers vectors,ḇt, were of the type , each dislocation being of edge character. TEM examination under proper weak-beam conditions seemed initially to show the standard contrast behaviour for such dislocations, indicating some dislocation segments were undissociated (contrast A), while other segments were dissociated to give two Shockley partials separated by approximately 6nm (contrast B) . A more detailed examination, however, revealed that some segments exhibited a third and anomalous contrast behaviour (contrast C), interpreted here as being due to a new dissociation not previously reported. Experimental results obtained for a dislocation along [211] with for the six <220> type reflections using (g,5g) weak-beam conditions are summarised in the table below, together with the relevant values.


Author(s):  
Scott Lordi

Vicinal Si (001) surfaces are interesting because they are good substrates for the growth of III-V semiconductors. Spots in RHEED patterns from vicinal surfaces are split due to scattering from ordered step arrays and this splitting can be used to determine the misorientation angle, using kinematic arguments. Kinematic theory is generally regarded to be inadequate for the calculation of RHEED intensities; however, only a few dynamical RHEED simulations have been attempted for vicinal surfaces. The multislice formulation of Cowley and Moodie with a recently developed edge patching method was used to calculate RHEED patterns from vicinal Si (001) surfaces. The calculated patterns are qualitatively similar to published experimental results and the positions of the split spots quantitatively agree with kinematic calculations.RHEED patterns were calculated for unreconstructed (bulk terminated) Si (001) surfaces misoriented towards [110] ,with an energy of 15 keV, at an incident angle of 36.63 mrad ([004] bragg condition), and a beam azimuth of [110] (perpendicular to the step edges) and the incident beam pointed down the step staircase.


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