The requirements of the airworthiness of aircraft

Cílem této práce je zjistit požadavky a postupy pro získání a zachování osvědčení letové způsobilosti letadel a výrobků letadlové techniky v rozsahu civilního letectví. Vyšetřované požadavky zahrnují normy týkající se požadavků na letovou způsobilost přes návrh, výrobu a provoz letadlové techniky.The focus of this study is to investigate the requirements and procedures for obtaining and maintaining a certificate of airworthiness of aircraft and aeronautical products within the scope of civil aviation. The requirements investigated include the standards regarding airworthiness requirements for large airplanes, helicopters, small airplanes, engines, and propellers. The procedures for certification and continuing airworthiness throughout the design, production and operating life of an aircraft are explained.

The Diverse Properties of GPS Sources

We discuss the morphology and kinematics of five gigahertz-peaked spectrum (GPS) sources that have been observed with the VLBA. We find a wide range of observed properties including core-jet structure, superluminal motion, variability, extended structure, and polarization, all of which appear to deviate from commonly-accepted GPS paradigms (e.g., O'Dea 1998). We suggest that the observed low frequency cutoff in GPS sources may be primarily due to free-free absorption rather than synchrotron self-absorption.Comment: Proceedings of the 6th European VLBI Network Symposium, Ros E., Porcas R.W., Lobanov, A.P., & Zensus, J.A. (eds), MPIfR, Bonn, Germany. (4 pages, 5 figures, needs evn2002.cls style file

Yearly licensing studies from 1997 to 2007 of the inactivated whole virus seasonal influenza vaccine fluval--a useful approach to pandemic vaccine development even in less well developed countries?

OBJECTIVE: Seasonal vaccination has been consistently shown to significantly reduce morbidity and mortality because of influenza epidemics, even in healthy, working adults. Here we report the results of the yearly licensing studies of the past 11 influenza seasons (1997-2007) with a trivalent, inactivated whole virus vaccine with an aluminum phosphate adjuvant system. METHODS: Sixty healthy volunteers per age group (18-60 years and 60 years and older) were enrolled to receive vaccination each year, thus, a total of 1080 subjects were studied. Serum antibody titers were measured by hemagglutination inhibition (HI). RESULTS: The vaccine met the criteria for licensing each year, meaning seroprotection (achievement of an HI titer of >1:40 in >70% of subjects); seroconversion, i.e. a >4-fold increase in HI antibody titer, or reaching a titer of >1:40, in >40% of subjects; and an increase in geometric mean titers by >2.5-fold. Side effects were rare and mild. The same method was used to produce a pre-pandemic vaccine against influenza A (H5N1), which has been shown to be safe and immunogenic in humans. CONCLUSIONS: We conclude that the method presented is safe, effective and may serve as a useful approach to seasonal and pandemic vaccine production even in less well-developed countries by means of technological transfer

VSOP observation of the quasar PKS 2215+020: a new laboratory for core-jet physics at z=3.572

We report results of a VSOP (VLBI Space Observatory Programme) observation of a high redshift quasar PKS 2215+020 (z=3.572). The ~1 milliarcsecond resolution image of the quasar reveals a prominent `core-jet' structure on linear scales from 5/h to 300/h pc ($H_0=100*h km/(s*Mpc). The brightness temperatures and sizes of bright features identified in the jet are consistent with emission from relativistic shocks dominated by adiabatic energy losses. The jet is powered by the central black hole with estimated mass of ~4*10^9 solar masses. Comparisons with VLA and ROSAT observations indicate a possible presence of an extended radio/X-ray halo surrounding 2215+020.Comment: 15 pages, 6 figures, aastex macros; accepted for publication in The Astrophysical Journal, V.546, N.2 *(January 10 2001

Observations of the bright radio sources in the North Celestial Pole region at the RATAN-600 radio telescope

A survey of the North Celestial Pole region using the RATAN-600 radio telescope at five frequencies in the range 2.3 to 21.7 GHz is described. Sources were chosen from the NVSS catalogue. The flux densities of 171 sources in the Declination range +75 to +88 are presented; typical flux density errors are 5-10 percent including calibration errors. About 20 percent of the sources have flat spectra or a flat component.Comment: 21 pages, 7 figures; to be published in Astronomy and Astrophysics (without last figure with the spectra of the observed sources

VLBI imaging of extremely high redshift quasars at 5 GHz

We present very long baseline interferometry (VLBI) images of ten very high redshift (z>3) quasars at 5 GHz. The sources 0004+139, 0830+101, 0906+041, 0938+119 and 1500+045 were observed in September 1992 using a global VLBI array, while 0046+063, 0243+181, 1338+381, 1428+423 and 1557+032 were observed in October 1996 with the European VLBI Network and Hartebeesthoek, South Africa. Most of the sources are resolved and show asymmetric structure. The sample includes 1428+423, the most distant radio loud quasar known to date (z=4.72). It is barely resolved with an angular resolution of about 2.0*1.4 mas.Comment: Astronomy and Astrophysics, in press, Latex2e, 10 pages, 3 figures (and lots of sub-figures

FIRST-based survey of Compact Steep Spectrum sources I. MERLIN images of arc-second scale objects

Compact Steep Spectrum (CSS) sources are powerful extragalactic radio sources with angular dimensions of the order of a few arcseconds or less. Such a compactness is apparently linked to the youth of these objects. The majority of CSSs investigated so far have been known since the early 1980s. This paper is the first in a series where we report the results of an observational campaign targeted on a completely new sample of CSSs which are significantly weaker than those investigated before. The ultimate goal of that campaign is to find out how ``weak'' CSSs compare to ``strong'', classical ones, especially with regard to the morphologies. Here we present an analysis of morphological and physical properties of five relatively large sources based on MERLIN observations at 1.6 and 5 GHz.Comment: 8 pages, 7 figures, A&A in pres

Predictions for high-frequency radio surveys of extragalactic sources

We present detailed predictions of the contributions of the various source populations to the counts at frequencies of tens of GHz. New evolutionary models are worked out for flat-spectrum radio quasars, BL Lac objects, and steep-spectrum sources. Source populations characterized by spectra peaking at high radio frequencies, such as extreme GPS sources, ADAF/ADIOS sources and early phases of gamma-ray burst afterglows are also dealt with. The counts of different populations of star-forming galaxies (normal spirals, starbursts, high-z galaxies detected by SCUBA and MAMBO surveys, interpreted as proto-spheroidal galaxies) are estimated taking into account both synchrotron and free-free emission, and dust re-radiation. Our analysis is completed by updated counts of Sunyaev-Zeldovich effects in clusters of galaxies and by a preliminary estimate of galactic-scale Sunyaev-Zeldovich signals associated to proto-galactic plasma.Comment: 12 pages, 14 figures, to be published in A&

The Overview of Propellers in General Aviation

Cílem této práce je sestavení přehledu konstrukčních řešení vrtulí používaných u letounů všeobecného letectví spolu s přehledem technických, provozních a ekonomických parametrů jednotlivých typů pohonných jednotek s důrazem na aplikované konstrukční řešení vrtule. Vyšetřované druhy vrtulí zahrnují pevné, na zemi stavitelné, dvoupolohové, manualné, automatické, a vrtule s konstantní rychlostí. Konstrukce, provoz a údržba každého z těchto systémů je vysvětlena a navzájem porovnána. Kromě toho jsou vyšetřované podporní systémy vrtule jako ochrana proti námraze a synchronizace, definována je základní teorie vrtule.The purpose of this study is to investigate the technical, operational, and economical aspects of various propeller systems in conjunction with their associated power plants within the scope of General Aviation. Types of propellers investigated include the fixed pitch, ground adjustable, two position, controllable pitch, automatic pitch changing, and the constant speed propeller. The construction, operation, and maintenance of each of these propeller systems is explained and compared. In addition, propeller auxiliary systems such as ice elimination and simultaneous control systems are investigated, and basic propeller theory is defined.

A kinematic study of the compact jet in quasar B3 1633+382

We present a study of the motion of compact jet components in quasar B3 1633+382. Through analyzing 14 epochs of VLBI observations of three components (B1, B2, and B3) at 22 GHz, we find two different possibilities of component classification. Thus two corresponding kinematical models can be adopted to explain the evolutionary track of components. One is a linear motion, while another is a helical model. Future observations are needed to provide new kinematical constraints for the motion of these components in this source.Comment: 7 pages, 3 figures; Accepted for publication in A&