Felhőfizikai folyamatok mezoskálájú modellezése = Numerical simulation of cloud physics in mesoscale processes

I. Mikrofizikai folyamatok számítógépes modellezése Megvizsgáltuk, hogy a sekélyrétegfelhőben lejátszódó csapadékképződést milyen mértékben befolyásolja az aeroszolrészecskék méret szerinti eloszlása és anyagi összetétele, valamint a jégképző részecskék koncentrációja. a) A csapadékképződéshez szükséges idő erősen függ a csapadékképződésben szerepet játszó aeroszolrészecskék (kondenzációs magvak) koncentrációjától. A csapadékképződést nem befolyásolja érdemben az 1 mikrométernél nagyobb óriás kondenzációs magvak jelenléte. b) Az aeroszolrészecskék vízben oldódó részének arányának csökkenése csökkenti az 50 mikrométernél nagyobb vízcseppek kialakulásához szükséges időt. A hatás annál jelentősebb, minél nagyobb az aeroszolrészecsekék koncentrációja. c) A jégképző részecskék koncentrációja hatással van a túlhűlt vízcseppek koncentrációjára. Ez a hatás annál jelentősebb, minél magasabb a vízcseppek koncentrációja. II. A felszín és a felhőfizikai folyamatok kapcsolata Esettanulmány segítségével igazoltuk, hogy a zivatarfelhők szerkezete és a belőlük hulló csapadék mennyisége érzékeny a talaj fizikai féleségére. III. Ultrarövidtávú, 6-12 órás előrejelzések készítése mezoskálájú modell segítségével. Kísérletek végeztünk a radar adatok numerikus modellekbe történő asszimilációjára. Az eredmények azt mutatják, hogy a módszerrel képesek vagyunk kényszeríteni a modellt arra, hogy a konvekciót ott indítsa be, ahol az a radarmérések alapján ténylegesen zajlik, sőt, egy erősebb behatással akár hevesebb eseményeket is gerjeszthetünk a modell állapotterében. | I. Numerical simulation of microphysics. Effect of the size distribution and chemical composition of the aerosol particles on the precipitation development in a shallow layer cloud was investigated. a) The time necessary for the development of the drizzle size drops (> 50 micron) strongly depends on the concentration of the aerosol particles. The precipitation formation is hardly affected by the presence of the giant nuclei (>1 micron). b) The lower water soluble fraction of the aerosol particles results in faster formation of drizzle. The larger the concentration of the aerosol particles is the larger the effect. c) The concentration of the aerosol particles what the ice crystals formed on affects the concentration of the supercooled water drops. This effect was found to be the largest in the case, where the drop concentration was the largest. II. The interaction between cloud physics and processes take place in the ground layer. A cased study was made to prove the effect of the soil type on the structure of the thunderstorms and on the precipitation formation in them. III. Application of the mesoscale model (MM5) for ultra short range forecast. Numerical experiments were made to study the effect of the radar data assimilation on the results of the numerical simulation of thunderstorm formation. It was found, that the assimilation of the radar data improves the accuracy of forecast of thunderstorm formation

Generation of Simulation Based Operational Database for an Acid Gas Removal Plant with Automatic Calculations

Computer aided process design is improving with newer and newer tools. One of such tools is the automatic calculation technique that enables the combination of different software tools to enhance the efficiency of the calculations. In our research work Aspen HYSYS model of a petrochemical plant is built in order to simulate responses of an existing plant to the changes in the composition and amount of feed material. The Aspen HYSYS is connected to Microsoft Excel program; simu-lated operational data are stored in an operational database and transported to Excel for further analysis. The automatic calculation completed with the two software tools mutually strengthens their merits and results in enhanced insight into the operational features of any plant. Comparison of the projected input parameters of the petrochemical plant studied shows that the extension of the plant is badly needed. Cash-flow analysis suggests that the extension is profitable

Observations of the relationship between sprite morphology and in-cloud lightning processes

[1] During a thunderstorm on 23 July 2003, 15 sprites were captured by a LLTV camera mounted at the observatory on Pic du Midi in the French Pyrénées. Simultaneous observations of cloud-to-ground (CG) and intracloud (IC) lightning activity from two independent lightning detection systems and a broadband ELF/VLF receiver allow a detailed study of the relationship between electrical activity in a thunderstorm and the sprites generated in the mesosphere above. Results suggest that positive CG and IC lightning differ for the two types of sprites most frequently observed, the carrot- and column-shaped sprites. Column sprites occur after a short delay (<30 ms) from the causative +CG and are associated with little VHF activity, suggesting no direct IC action on the charge transfer process. On the other hand, carrot sprites are delayed up to about 200 ms relative to their causative +CG stroke and are accompanied by a burst of VHF activity starting 25–75 ms before the CG stroke. While column sprites associate with short-lasting (less than 30 ms) ELF/VLF sferics, carrot sprites associate with bursts of sferics initiating at the time of the causative +CG discharge and persisting for 50 to 250 ms, indicating extensive in-cloud activity. One carrot event was found to be preceded by vigorous IC activity and a strong, long-lived cluster of ELF/VLF sferics but lacking a +CG. The observations of ELF/VLF sferic clusters associated with lightning and sprites form the basis for a discussion of the reliability of lightning detection systems based on VHF interferometry.Peer ReviewedPostprint (published version

Chromatic periodic activity down to 120 MHz in a Fast Radio Burst

Fast radio bursts (FRBs) are extragalactic astrophysical transients whose brightness requires emitters that are highly energetic, yet compact enough to produce the short, millisecond-duration bursts. FRBs have thus far been detected between 300 MHz and 8 GHz, but lower-frequency emission has remained elusive. A subset of FRBs is known to repeat, and one of those sources, FRB 20180916B, does so with a 16.3 day activity period. Using simultaneous Apertif and LOFAR data, we show that FRB 20180916B emits down to 120 MHz, and that its activity window is both narrower and earlier at higher frequencies. Binary wind interaction models predict a narrower periodic activity window at lower frequencies, which is the opposite of our observations. Our detections establish that low-frequency FRB emission can escape the local medium. For bursts of the same fluence, FRB 20180916B is more active below 200 MHz than at 1.4 GHz. Combining our results with previous upper-limits on the all-sky FRB rate at 150 MHz, we find that there are 3-450 FRBs/sky/day above 50 Jy ms at 90% confidence. We are able to rule out the scenario in which companion winds cause FRB periodicity. We also demonstrate that some FRBs live in clean environments that do not absorb or scatter low-frequency radiation.Comment: 50 pages, 14 figures, 3 tables, submitte

Elektronikus pénzügyi szolgáltatások a Takarékszövetkezeteknél

Szakdolgozatom az elektronikus pénzügyi szolgáltatások a Takarékszövetkezeteknél szól. Bevezetésben egy rövid történetben ismertetem a Takarékszövetkezeteket.Bemutatom a szolgáltatások kialakulását, majd részletezem őket. Végül a Takarékszövetkezetekről készítettem egy SWOT analízist.felsőoktatási szakképzésPénzügyi Szakügyintézővtv

Observations of the relationship between sprite morphology and in-cloud lightning processes

[1] During a thunderstorm on 23 July 2003, 15 sprites were captured by a LLTV camera mounted at the observatory on Pic du Midi in the French Pyrénées. Simultaneous observations of cloud-to-ground (CG) and intracloud (IC) lightning activity from two independent lightning detection systems and a broadband ELF/VLF receiver allow a detailed study of the relationship between electrical activity in a thunderstorm and the sprites generated in the mesosphere above. Results suggest that positive CG and IC lightning differ for the two types of sprites most frequently observed, the carrot- and column-shaped sprites. Column sprites occur after a short delay (<30 ms) from the causative +CG and are associated with little VHF activity, suggesting no direct IC action on the charge transfer process. On the other hand, carrot sprites are delayed up to about 200 ms relative to their causative +CG stroke and are accompanied by a burst of VHF activity starting 25–75 ms before the CG stroke. While column sprites associate with short-lasting (less than 30 ms) ELF/VLF sferics, carrot sprites associate with bursts of sferics initiating at the time of the causative +CG discharge and persisting for 50 to 250 ms, indicating extensive in-cloud activity. One carrot event was found to be preceded by vigorous IC activity and a strong, long-lived cluster of ELF/VLF sferics but lacking a +CG. The observations of ELF/VLF sferic clusters associated with lightning and sprites form the basis for a discussion of the reliability of lightning detection systems based on VHF interferometry.Peer Reviewe