The authors analysed so-called light-cut method which is suitable for the quick and accurate measurement of the profile. The main attention is paid to mathematical methods of evaluation of the laser spot centre on a measured surface. A novel method of centre evaluation is based upon approximation of laser spot intensity distribution by polynomial of second order. This method gives the best results from the point of view of minimizing measurement uncertainty. and Autori analyzovali metódu svetelného rezu, ktorá je vhodná pre rýchle a presné meranie profilu. Hlavná pozornosť je venovaná matematickým metódam vyhodnotenia stredu laserovej stopy na meranom povrchu. Nový spôsob vyhodnotenia stredu je založený na aproximácii rozloženia intenzity laserovej stopy polynómom druhého rádu. Tento spôsob dáva najlepšie výsledky z hľadiska minimalizácie neistoty merania.
The dedicated satellite gravity missions have provided homogeneous and uniformly accurate information on the long and medium wavelengths of the Earth’s gravity field. Since the launch of GOCE satellite gravimetry mission by the European Space Agency (ESA) in 2009, several global geopotential models (GGMs) have been published. This study evaluates the recent GOCE-based GGMs over the area of Poland. The evaluation has been performed with the use of the EGM08 as well as high-precision GPS/levelling control traverse consisting of 184 stations. One GOCE-only GGM, four GOCE/GRACE satellite-only GGMs, and one GOCE/GRACE GGM combined with terrestrial gravity data have been selected for the evaluation. The results of inter-comparison of the models as well as their accuracy assessment have been discussed., Walyeldeen Godah and Jan Krynski., and Obsahuje bibliografii
This study was carried out to determine the possible use of evapotranspiration estimation (combination) methods under different climatic conditions of Turkey. Reference evapotranspiration values were calculated according to Penman (1963; Original wind function), FAO-24 Corrected Penman, Penman (Daytime wind speed), Kimberly-Penman (1972), Kimberly-Penman (1982), FAO-PPP-17, Penman (Merva-Fernandez), Penman-Monteith and Penman-Monteith (FAO) for selected 20 locations with different climatic conditions. Reference evapotranspiration (ET0) assessments were analyzed according to their annually, 8 monthly (March-October) and 3 monthly (June-August) values. In all periods evaluated, almost the same significant differences (P<0.01) were found between locations and methods. High ET0 values were obtained in the locations with high wind speed and low relative humidity. Low ET0 values were observed in the locations with low daily sunshine duration. In conclusion, FAO-PPP-17, Penman (Merva-Fernandez), Penman-Monteith and Penman-Monteith (FAO) could be more efficiently used. Penman (Daytime wind speed) and FAO-24 Corrected Penman over-predicted ET0 values as compared to other methods. and Referát obsahuje výsledky výpočtu referenčnej evapotranspirácie pomocou kombinovanej metódy, aplikovanej na klimatické podmienky Turecka. Referenčná evapotranspirácia (ET0) - čo je potenciálna evapotranspirácia referenčného porastu - bola vypočítaná podľa Penmana (1963; Originálna ''vetrová'' funkcia), upravenou metódou Penmana, označenou ako FAO-24, modifikovanou metódou Penmana (bola použitá rýchlosť vetra len počas dňa), metódou Kimberly-Penman(1972), Kimberly-Penman (1982), metódou FAO-PPP-17, Penmana (podľa autorov Merva-Fernandez), Penmana-Monteitha a Penmana-Monteitha (podľa FAO). Vybrali sme 20 lokalít s rozdielnymi klimatickými podmienkami na území Turecka, ktorých klimatické charakteristiky boli použité v uvedených metódach výpočtu referenčnej evapotranspirácie. Referenčná evapotranspirácia (ET0) pre ročné, 8-mesačné (marec - október) a trojmesačné (jún - august) obdobia bola podrobená analýze, v závislosti na metóde, ktorou bola určená. Pre všetky analyzované obdobia boli nájdené skoro také isté rozdiely medzi lokalitami a metódami (P < 0,01). Vysoké hodnoty ET0 boli určené pre lokality s výskytom vysokej rýchlosti vetra a nízkej relatívnej vlhkosti vzduchu. Nízke hodnoty ET0 boli určené pre lokality s krátkym trvaním slnečného svitu. Možno zhrnúť, že niektoré metódy dávajú realistické výsledky - FAO-PPP-17, Penmanova metóda (verzia autorov Merva - Fernandez), metóda Penmana-Monteitha a Penmana-Monteitha (FAO). Metóda Penmanova (použitá rýchlosť vetra len počas dňa) a upravená metóda Penmana, označená ako FAO-24, v porovnaní s inými metódami vypočítanú referenčnú evapotranspiráciu výrazne nadhodnocujú.
The effectiveness of eight spectral reflectance indices for estimating chlorophyll (Chl) content in leaves of Eugenia uniflora L., a tropical tree species widely distributed throughout the world and a key species for ecosystem restoration projects, was evaluated. Spectral reflectance indices were tested using sun and shade leaves with a broad variation in leaf mass per area (LMA). Shortly after plants were exposed to chilling temperatures, there was a dramatic visible change in some sun leaves from green to red. Prior to testing Chl-related reflectance indices, the green and red leaves were separated according to the anthocyanin reflectance index (ARI). Slightly green to dark green leaves corresponded to an ARI value less than 0.11 (n = 107), whereas slightly red to red leaves corresponded to an ARI value greater than 0.11 (n = 35). To estimate leaf Chl, two simple reflectance indices (SR680 and SR705), two normalized difference indices (ND680 and ND705), two modified reflectance indices (mSR705 and mND705), a modified Chl absorption ratio index (mCARI705) and an index insensitive to the presence of anthocyanins (CIre) were evaluated. Good estimates of leaf Chl content were obtained using the reflectance indices tested regardless of the presence of anthocyanins and changes in LMA. Based on the coefficients of determination (r2) and the root mean square errors (RMSɛc) the best results were obtained with reflectance indices measured at wavelengths of 750 and 705 nm. Considering the performance of the models the best reflectance indices to estimate Chl contents in E. uniflora leaves with a broad variation in LMA and anthocyanin contents was SR705 and mCARI705., M. S. Mielke, B. Schaffer, A. C. Schilling., and Obsahuje bibliografii
From 29th March to 09th April 2006, the Morava catchment in the Danube River basin was hit by severe flooding caused by snow melting and rainfall. The floods affected settlements and agricultural lands in Slovakia, Czech Republic and Austria. In the downstream Morava, 100-year flood and more peak discharges were observed. The European Flood Alert System (EFAS), under development and running in pre-operational mode at the Joint Research Center of the European Commission, in partnership with Member States’ authorities and meteorological data providers, forecasted the event more than five days in advance. This paper investigates the performance of EFAS hydrologic forecasts for this event. Forecasts based on deterministic and probabilistic weather forecasts are presented and verified against observed data. The analysis showed that forecasts based on probabilistic weather ensembles were able to detect an earlier signal of the flood event. The lack of consistence between simulations based on different medium-range weather forecasts was the main reason for a late diffusion of EFAS forecasts to its partner in Slovakia, with an impact on the value of the forecasts as a pre-alert. The potential benefit of ensemble hydrologic forecasts to early flood warning and increased preparedness is highlighted. and V období 29. marca až 9. apríla 2006 zasiahla povodie Moravy, ktoré je súčasťou povodia Dunaja ničivá povodeň, zapríčinená prevažne topením sa snehu v kombinácii s pomerne výdatnou zrážkovou činnosťou. Povodeň spôsobila škody na obydliach a poľnohospodárskej pôde v Českej republike, Rakúsku a aj na Slovensku. V dolnej časti toku Morava bol zaznamenaný kulminačný prietok s dobou opakovania viac ako 100 rokov. Európsky povodňový varovný systém, vyvinutý a prevádzkovaný v tzv. predoperačnom režime JRC EU v spolupráci s členskými štátmi, ktoré sú aj poskytovateľmi hydrometeorologických údajov, prognózoval túto rozsiahlu povodňovú epizódu s predstihom 5 dní. Príspevok sa zameriava na skúmanie realizácie hydrologických predpovedí z EFAS systému pre uvedenú povodňovú udalosť. Predpovede vypočítané na základe deterministických a pravdepodobnostných predpovedí počasia sú verifikované pozorovanými údajmi. Analýza výsledkov ukázala, že predpovede robené na základe pravdepodobnostných ansámblových predpovedí vývoja počasia boli schopné dať signál, že sa povodňová udalosť stane, s väčším intervalom predstihu. V dôsledku nekonzistencie vyhodnocovaných predpovedí bola slovenskému partnerovi EFAS-u odoslaná oneskorene. Príspevok poukázal tiež na skutočnosť, že využitie ansámblov pre hydrologické predpovede a včasné varovanie pred nebezpečenstvom povodní umožňuje v dostatočnom predstihu zlepšiť pripravenosť na tieto udalosti.
The benefit of percutaneous transluminal angioplasty (PTA) of transplant renal artery stenosis for ischemic nephropathy may be adversely affected by rejection or other complications. As a result, assessment of the effect of PTA on renal function or blood pressure is often difficult. In this paper, we evaluated the effect of PTA using the method of integrated glomerular filtration rate (GFR) based upon the area under the curve over a follow-up period (AUC0-t), to express the level of GFR in a simple manner despite its significant fluctuations. A similar procedure was used to evaluate mean arterial pressure (MAP). The method was employed to assess the outcome in 20 individuals before PTA, and 1, 3, 6, 9 and 12 months after PTA. In eight cases, rejection was detected while there was one case of glomerulonephritis in the graft during the follow-up period. Evaluation (AUCCcr)0-12 related to the integrated pre-PTA value of Ccr [(Ccr)0 x 12] revealed a rise in GFR by more than 20 % in 65 % of cases. No improvement was observed in seven individuals with post-PTA complications. When assessing the integrated value of MAP, success of PTA (a reduction by at least 10 %) was found in 85 % of cases. No significant correlation was found between the relative changes of integrated GFR and MAP. Our data suggest that evaluation of the integrated value of GFR or MAP on the basis of AUC0-t allows to characterize, in a simple manner, the level of graft function and MAP throughout the follow-up period in individual cases. Furthermore, it may provide additional information on the average values obtained at different time intervals after the therapeutic procedure., J. Stříbrná, O. Schück, J.H. Peregrin, D. Krajíčková, J. Skibová., and Obsahuje bibliografii
Ionic environment is important in regulating photosynthetic reactions. The roles of cations, Mn2+, Mg2+, Ca2+, Na+, and K+ as cofactors in electron transport, energy transfer, phosphorylation, and carbon assimilation are better known than the roles of anions, except for chloride and bicarbonate. Only a limited information exists on the roles and effects of nitri formate, sulphate, and phosphate. In this review, we evaluate and highlight the roles of some specific anions on electron transport as well as on excitation energy transfer processes in photosynthesis. Anions exert significant effects on thyla membrane conformation and membrane fluidity, possibly by redistributing the thylakoid membrane surface charges. The anion/cation induced phase transitions in the hydrophilic domains of the thylakoid membranes are probably responsible for the various structural and co-related functional changes under stress. Anions are also important in regulation of energy distribution between the two photosystems. Anions do not only divert more energy from photosystem (PS) 2 to PS1, but can also reverse the effect of cations on energy distribution in a valence-dependent manner. Anions affect also the structure of the photosynthetic apparatus and excitation energy distribution between the two photosystems. and A. Jajoo, S. Bharti, P. Mohanty.
A suitability of the bladed disk design regarding the possibility of the resonant vibration excitation can be assessed on the basis of several approaches. Most information concernng the evaluation of the bladed disk design suitability is provided in theSAFE diagram but the possibility of exciting the action wheel resonant vibration can also be evaluated from the Campbell diagram. Further criterion is the assessment of the design suitability on the basis of a critical speed of the bladed disk. It expecially causes breakdowns of relatively flexible disks. The suitability of the bladed disk with the blades of the ZN340-2 type was evaluated. and Obsahuje seznam literatury
The convolution sum $$ \sum\limits_{\substack{m=1 \\ m\equiv a\pmod 4}}^{n-1} \sigma (m) \sigma (n-m) $$ is evaluated for $a\in
\{ 0,1,2,3\}$ and all $n \in \Bbb N$. This completes the partial evaluation given in the paper of J. G. Huard, Z. M. Ou, B. K. Spearman, K. S. Williams.
Several multiaxial fatigue criteria have been developed and improved within the last couple of decades, but they are not very widely used in industrial applications. Many engineers and designers still use simple uniaxial criteria for multiaxial load cases. In order to test and validate / discard these uniaxial criteria on the basis of multiaxial load cases, the present work presents a comparison between several uniaxial criteria applied to a large set of experimental results for smooth unnotched samples tested under multiaxial loading. The effect of mean stress is also evaluated in order to determinate how it affects the final results. and Obsahuje seznam literatury