Evolution of the flow field in decaying active regions, Transition from a moat flow to a supergranular flow

We investigate the evolution of the horizontal flow field around sunspots during their decay by analysing its extension and horizontal velocity around eight spots using SDO/HMI Doppler maps. By assuming a radially symmetrical flow field, the applied analysis method determines the radial dependence of the azimuthally averaged flow field. For comparison, we studied the flow in supergranules using the same technique. All investigated, fully fledged sunspots are surrounded by a flow field whose horizontal velocity profile decreases continuously from 881 m s$^{-1}$ at 1.1 Mm off the spot boundary, down to 199 m s$^{-1}$ at a mean distance of 11.9 Mm to that boundary. Once the penumbra is fully dissolved, however, the velocity profile of the flow changes: The horizontal velocity increases with increasing distance to the spot boundary until a maximum value of about 398 m s$^{-1}$ is reached. Then, the horizontal velocity decreases for farther distances to the spot boundary. In supergranules, the horizontal velocity increases with increasing distance to their centre up to a mean maximum velocity of 355 m s$^{-1}$. For larger distances, the horizontal velocity decreases. We thus find that the velocity profile of naked sunspots resembles that of supergranular flows. The evolution of the flow field around individual sunspots is influenced by the way the sunspot decays and by the interplay with the surrounding flow areas. Observations of the flow around eight decaying sunspots suggest that as long as penumbrae are present, sunspots with their moat cell are embedded in network cells. The disappearance of the penumbra (and consequently the moat flow) and the competing surrounding supergranular cells, both have a significant role in the evolution of the flow field: The moat cell transforms into a supergranule, which hosts the remaining naked spot.Comment: accepted for publication in A&A, 11 pages, 6 figures, 3 tables; appendix with 9 figures and 8 online movie

Engineering tests of the C-141 telescope

Data on image quality, chopper performance, and the closed-loop operation of the 91 cm telescope of the Kuiper Airborne Observatory which were obtained in September 1977 are presented

Remote car monitoring

Cílem této práce je navrhnout levné a efektivní zabezpečovací zařízení do automobilu, jehož maximální proud v hlídacím stavu bude do 1mA. Je provedeno základní rozdělení autoalarmů a popsány jejich hlavní výhody a nevýhody. Jako nejlepší možnost je nakonec zvolena koncepce GPS/GSM autoalarmu. V následující části je rozebrán návrh spínaného zdroje, komunikace po RS232 s GSM a GPS modulem, I2C komunikace s akcelerometrem a timerem a návrh modulu displeje. Dále je zde vysvětleno, jak kódovat a dekódovat PDU formát sms zpráv. V další části jsou uvedeny změřené základní charakteristiky spínaného zdroje (účinnost, spínací frekvence atd.). Následně je vysvětlen vývojový diagram hlavní programové smyčky. Také je rozebrán tvar sms, kterou autoalarm pošle v případě ukradení vozu. Poté je ukázáno, jak nastavit timer, mez zrychlení a dobu mezi kontrolami ovládacích sms. Pátá část se zabývá instalací autoalarmu do vozu (konkrétně ukázáno na Škodě Favorit). V šesté části jsou uvedeny ceny jednotlivých součástí a vyčísleny celkové náklady na zařízení. V poslední části je návrh shrnut a jsou dány vylepšovací návrhy.The main goal of this work is to design an efficient and cheap car-alarm with an electricity consumption not exceeding 1mA in the stand-by mode. The first part focuses on the conception of the car-alarm. As the best option - GPS/GSM car-alarm conception is chosen. Then the design of the switching power supply, communication via RS232 with the GSM module, and GPS module, I2C communication with accelerometer and timer IC, and design of the display module are described. Furthermore, the process of how to code/decode sms into the PDU format is also discussed in this part. The second part provides some basic empirical characteristics of the switching power supply (efficiency, switching frequency etc.). Then the owchart of the main loop is explained, followed by an example of the sms which the car-alarm sends in case a car theft. Explanation of how to set up timer, acceleration threshold and the time between the check of the sms commads is the subject of the next section. Fifth part deals with the installation the car-alarm into a car which is illustrated on the Skoda Favorit example. Total costs and also different cost items are listed just before concluding and suggesting some potential improvements of the device.

Grammatik in Fragen und Antworten : Grammatische Hilfestellung im Internet

To reach even language users not acquainted to the use of grammars the Institut für Deutsche Sprache in Mannheim (Germany) looked for new way to handle grammatical problems. Instead of confronting users with abstractions frequent difficulties of German grammar are introduced in form of exemplary questions like „Which form should be used or preferred: Anfang dieses Jahre or Anfang diesen Jahres?” Looking through the long list of such questions even laymen may find solutions of grammatical problems they might not be able to formulate as such