A method of determination the apparent resistyvity of the ground’s near-surface la yers from measurements of the mutual impedance of a loop antenna system operating at a high frequency is presented. An analysis of the sensitivity of mutual impedance to variation in the parameters of conducting half space at different frequencies had been carried out. Additionally influence of displacement current on measured mutual impedance values was discussed. A frequency of measuring system was selected in order to obtain a high sensitivity of the measuring system to detection inhomogeneities characterised by small dimensions and low apparent resistyvity contrast. The measuring system and the method of interpreting measurement results were described. The results of field measurements were presented., Grzegorz Beziuk and Remigiusz Mydlikowski., and Obsahuje bibliografické odkazy
A method to determine the optical parameters of thin films deposited on the thick transparent substrate is proposed. The method is based on the calculation of probability amplitude by the Feynman sum over trajectories. We can reproduce quickly known relation used in optics of thin films by this method and it could be generalized to other cases. We have discussed theoretically an accuracy of the method developed by Manifacier et al. [2]. and Je navržena metoda určení optických parametrů tenkých vrstev nanesených na tlustém transparentním substrátu. Metoda je založena na výpočtu amplitudy pravděpodobnosti pomocí Feynmanovy sumace přes trajektorie. Stručně reprodukujeme známé relace z optiky tenkých vrstev touto metodou, které lze zobecnit na jiné případy. Teoreticky diskutujeme o přesnosti metody navržené Manifacierem et al. [2].
The article is aimed at identifying the basic approaches for assessing the economic efficiency of public projects and their application whilst assessing the efficiency of preventive anti-flooding measures. One of the important things when deciding about applying these measures is information on what value of real estate assets these measures protect and what level of potential damages they are able to prevent. Within the research assignment, therefore, the issue of property indicators in the area is dealt with, based on which the value of real estate assets in the area can be determined, and subsequently the amount of damage can be specified for when the area is hit by potential natural disasters (flood) by using damage curves processed for individual representatives of real estate property. This problem is solved in the ''Procedures for supporting decision-making in the field of securing the stability of the area in terms of possible flooding'' grant project No. 103/05/0016 with support of the Czech Science Foundation. More information about this methodology is on www.fce.vutbr.cz/ekr, the final report of this project will carried in February 2008 also on http://pala.gacr.cas.cz/. and Článek je zaměřen na identifikaci základních přístupů pro hodnocení ekonomické efektivnosti veřejných projektů a jejich uplatnění při posuzování efektivnosti preventivních protipovodňových opatření. Pro rozhodování o uskutečnění těchto opatření je mimo jiné důležitá informace, jakou hodnotu nemovitého majetku tato opatření chrání, případně jak vysokým škodám jsou schopna zabránit. V rámci výzkumného projektu je proto řešena problematika územních majetkových ukazatelů, na základě kterých lze stanovit hodnotu nemovitého majetku v území a následně při zasažení území potenciální živelní pohromou - povodní s využitím křivek poškození zpracovaných pro jednotlivé reprezentanty nemovitého majetku vyčíslit výši škody. Tato problematika je řešena v grantovém projektu č. 103/05/0016 s názvem ''Postupy pro podporu a rozhodování v oblasti stavebních investic při zajištění stability území z pohledu možného zaplavení'' za podpory Grantové agentury České republiky. Více informací o vyvinuté metodice lze nalézt na www.fce.vutbr.cz/ekr; závěrečná zpráva projektu bude uveřejněna také na http://pala.gacr.cas.cz/.
PSI trimer to monomer ratio in intact cyanobacterial cells and isolated thylakoids was analysed by two noninvasive, in vivo methods; low-temperature fluorescence emission and circular dichroism spectroscopy. We measured fluorescence emission spectra of cells upon chlorophyll (Chl, 436 nm) excitation. All three species - Synechocystis sp. PCC 6803, Anabaena sp. PCC 7120, and Spirulina platensis - showed shifted Chl peak, indicating they have different spectral properties. CD spectroscopy revealed the highest intensity at 515 nm (PSI peak) in Spirulina platensis cells, which may originate from PSI multi-oligomerisation. The most sensitive response to heat treatment in this strain was the oligomerisation of PSI RCs. PSI dimers and tetramers in Anabaena cells showed smaller changes of the CD signal upon the heat treatment compared to that of Synechocystis WT. The lack of γ-linolenic acid affected the filament morphology by the loss of the spiral shape and the PSI monomerisation in Spirulina I22., T. Zakar, L. Kovacs, S. Vajravel, E. Herman, M. Kis, H. Laczko-Dobos, Z. Gombos., and Obsahuje bibliografické odkazy
This study shows the test usage of Mobile Automated Astronomical System No. 1 (M AAS-1) in a local network with an are a of approximately 50 km sq. The network has been built-up especially for experimental purposes to compare the local quasigeoid model determined by three different methods, namely GNSS-levelling, astronomical levelling and gravimetry. The network consists of 34 core points where the astronomic and geodetic coordinates have been measured. Subsequently, the measured data have been processed to obtain vertical deflections and to determine the quasigeoid heights by astronomical levelling. Afterwards, the quasigeoid model has been independently determined also using gravimetric measurements and by the method of GNSS-levelling. In this paper the results of th e comparison of quasigeoid models are being presented. The overall agreement of independently determin ed quasigeoids is on the level of 3 mm. After an overall accuracy evaluation of resulting quasigeoid model authors discuss the benef its of astronomical measur ements using MAAS-1., Tomáš Volařík, Radovan Machotka, Michal Kuruc, Lukáš Puchrik and Josef Jurčík., and Obsahuje bibliografické odkazy
This paper presents a case study for the strength demonstration of a railway wagon welded node using the probability approach. The design variables were taken from the existing standardization for railway vehicles. The fatigue damage summation method for proving the satisfactory service life as well as the Goodman diagram method for verification of the unlimited service life was used for the node examination. The probability estimation was made using the Monte Carlo SBRA method with the help of the Anthill software. and Obsahuje seznam literatury
This paper describes the researches upon the precise short-time GPS solutions made in the Centre of Applied Geomatics, Military University of Technology. The data from ASG-EUPOS (Polish Active Geodetic Network) was processed using Bernese 5.0 software and EPN (EUREF Permanent Network) standards and models. In this study, the adopted 3-hour observation window is shifted every hour obtaining geocentric coordinates in ITRF2005 reference frame. The adjusted network consisted of over 130 stations from Poland and the neighbouring countries, the period covered observations collected from 8.06.2008 to 18.06.2010. These two years of observations allowed to examine short-period oscillations which we found as closely related to the tidal (dynamic) frequencies. The analysis of the residua from IERS2003 tidal model was performed using least squares method with the Eterna software upon the idea of Chojnicki. It confirmed existence of the significant energy in the frequencies corresponding to S1, K1 and K2. The effects in S1 frequency reflect thermal influences, but the reasons of K1 and K2 existence could be both: dynamic (liquid core resonance and non-linearity of K1 are very difficult for modelling as well as the annual modulation of S1) or artificial (GPS satellites’ orbiting period, dynamic changes of satellites’ constellation and network geometry, multipath, residual tropospheric and ionospheric errors etc.). Since the phase of K1 for all 130 sites is very inconsistent the local effects could be also taken into account as one of the possible reasons. The paper describes the idea of the data processing and analysis, presents the results of vertical (Up component) oscillations in main tidal frequency bands, but also includes the discussion on the possible explanation of existence of short period oscillations in GPS precise solutions., Janusz Bogusz and Jan Hefty., and Obsahuje bibliografii
Five methods for determination of the resonant frequencies of the flexural vibration of a sample are shown. A simplified differential partial equation is used to estimate the values of the frequencies. For an unknown sample the Lissajous figure method as well as the method using different lengths of samples are most suitable. For samples with a known elastic behaviour a comparison of the fundamental mode and the 1st overtone frequencies can be used or a calculation of the resonant frequency from the dimensions and the known Young’s modulus can be made. and V článku je uvedených päť metód na určovanie rezonančnej frekvencie ohybového kmitania vzorky. Na určenie frekvencií je použitá zjednodušená parciálna diferenciálna rovnica. Pre neznámu vzorku a materiál je najvhodnejšou metódou na určenie rezonančných frekvencií metóda Lissajousových obrazcov. Pre vzorky so známym modulom pružnosti môže byť použité porovnanie frekvencií základného a prvého módu, alebo výpočet rezonančnej frekvencie pomocou vzoriek rôznych rozmerov.
Using synthetic data we study the possibility of determining 1-D velocity models of the upper crust from P- and S-wave arrival times in the case of a narrow depth interval of seismic sources and sparse distribution of stations. The test is tailored to a similar real situation in one subregion of the western part of the Corinth Gulf, Greece. Two kinds of models are studied: (i) models composed of layers with constant velocity gradients, and (ii) models composed of homogeneous layers. To derive the structural models from arrival times, the Neighbourhood Algorithm of Sambridge (1999) is used, combined with the grid search for source locations. Weighted P- and S-wave arrival time residuals are used as the misfit function. Accurate and perturbed synthetic arrival times are used. The velocities at medium depths, with a fast velocity increase, are well determined in both models for the accurate data. However, the determination of velocity is less certain in the uppermost 5 km for the gradient model, and in the deepest layer for the model composed of homogeneous layers for the perturbed data. The presence or absence of hypocentres in the uppermost or in the second layer influences notably the obtained velocity in these layers in both models., Jaromír Janský, Vladimír Plicka and Oldřich Novotný., and Obsahuje bibliografii