119 research outputs found
Halvány égi rádióforrások szerkezetének nagy felbontású térképezése = High resolution imaging of weak celestial radio sources
No full textNagyon hosszú bázisvonalú rádió-interferométeres (VLBI) csillagászati méréseket végeztünk nemzetközi antennahálózatokkal. A halvány extragalaktikus rádióforrások felmérését céló DEVOS programunkat beindítottuk. A kvazárok szerkezetét néhány ezred-ívmásodperces (mas) szöfelbontással tanulmányoztuk 5 GHz frekvencián, égi pozícióikat ~1 mas pontossággal határoztuk meg. A létrejövő minta kozmológiai, galaxisfejlődési, asztrometria célokra használható. A DEVOS-hoz újszerű VLBI megfigyelési módszert alkalmaztunk, s célpontjaink előzetes kiválasztására olyan eljárást dolgoztunk ki, amelynek alapján igen kedvező (közel 90%-os) detektálási arányt biztosíthatunk. Foglalkoztunk a DEVOS adatbázis, és a megfigyelési technika egyes alkalmazásaival. Bekapcsolódtunk egy nemzetközi programba, amelynek célja a közeljövő hatalmas optikai teleszkópjai pontos asztrometriai kalibrációjának megoldása VLBI mérések segítségével. A világegyetem legtávolabbi (z=5,77) ismert rádiókvazárját mas skálán feltérképeztük. Publikáltuk az AO 0235+164 blazárra vonatkozó űr-VLBI észleléssorozatunk eredményeit. Különösen nagy vöröseltolódású (z>3) kvazárokat kutattunk űr-VLBI technikával. Részt vettünk a nagyszámú aktív galaxismag űr-VLBI felmérését célzó programban. Foglalkoztunk a közepes tömegű fekete lyukak VLBI technikával való detektálhatóságával. Mosoni L. a futamidő alatt védte meg a DEVOS programban végzett kutatómunkájával kapcsolatban készített PhD értekezését. | We conducted radio interferometric astronomical experiments with Very Long Baseline Interferometry (VLBI), using international telescope networks. Our Deep Extragalactic VLBI?Optical Survey (DEVOS) aims at constructing a large sample of faint compact radio-emitting active galactic nuclei (AGNs). We imaged the radio structures of AGNs at a few milli-arcsecond (mas) angular resolution at 5 GHz. The positions of the sources are determined with mas accuracy. The sample will be invaluable for cosmological, astrophysical and astrometric studies. For DEVOS, we applied a novel observing technique and developed a target selection method thet provides nearly 90% VLBI detection rate. We studied some applications of the DEVOS data and the observing technique itself. We joined an international endeavour to prepare for the sufficiently precise astrometric calibration of next-generation large-aperture optical telescopes, with the help of VLBI. We imaged the most distant (z=5.77) radio-loud quasar known in the Universe. We published the results of our space VLBI monitoring observations of the blazar AO 0235+164. We studied quasars at extremly high redshifts (z>3) with space VLBI. We took part in the 5-GHz VSOP Survey Program. We investigated the possibility of detecting intermediate-mass black holes with the current VLBI networks. One of the participants, L. Mosoni obtained his PhD degree for his work with the DEVOS pilot study during the reported period
Probing the temporal and spatial variations of dust emission in the protoplanetary disk of DGTau with VLTI/MIDI: Preliminary results
No full textThe signatures of dust processing and grain growth - related to the formation of rocky planets - are easily seen in midinfrared spectral features. One important diagnostic tool in this context is the silicate feature in the spectra of young stellar objects (YSO). The low-mass YSO, DG Tau shows unique temporal variations in its silicate feature. We conducted multi-epoch observations of DG Tau with the MID-Infrared Interferometric instrument of the Very Large Telescope Interferometer to obtain the spectra of the inner and outer disk regions in order to investigate where the previously reported variations of the silicate feature originate from. Here we present the preliminary results of the first two epochs of observations. We found that on a time-scale of two months, the source showed significant brightening. At the same time the mid-infrared emitting region expanded. While the identification of the silicate feature is difficult, our results qualitatively agree with the scenario explaining the varying silicate feature with dust lifted up above the disk. ((c) 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Interferometry in radio and infrared
No full textIn this paper I give three brief examples, two astrophysical applications and an image reconstruction study for a future instrument, of interferometric projects in which Hungarian groups are involved
Reactivity of aluminum sulfate and silica in molten alkalimetal sulfates in order to prepare mullite
No full textWith the aim of preparing mullite, reactions between aluminum sulfate and silica in appropriate proportions and molten sulfate media M2SO4 (M=Na and/or K) were performed at different temperatures. The powders obtained were characterized by XRD, FT-IR, SEM and TEM. The reactivity was the same in Na2SO4 and (K,Na)2SO4 media. The best results in terms of yield (98.3%) and weight of mullite produced (95%) were obtained in Na2SO4 at 950 °C. The mullite phase exhibits an acicular morphology (75×0.75 μm) and a specific surface area close to 20 m2/g. In K2SO4 medium, a potassium alumino silicate is formed as well as mullite
A comprehensive review of key cyber-physical systems, and assessment of their education challenges
No full textL
2nd WORKSHOP OF Young Researchers in Astronomy & Astrophysics Hungary, January 2002
No full textContents
Preface
List of Participants
Application of (Magneto)hydrodynamics
Emese Forgács-Dajka:
A possible model for the fast solar tachocline
Dániel Marik and Róbert Erdélyi:
Numerical Simulations of Blinker Events
Róbert Szabó and Zoltán Csubry:
RR Lyrae variables: pulsation and evolution
Celestial Mechanics
András Pál and Zsolt Sándor:
On the Stability of Habitable Zones in Exoplanetary Systems
Zsolt Sándor:
Some aspects of the chaotic diffusion of Trojan asteroids
Áron Süli and Rudolf Dvorak:
The fundamental frequencies of N-body Systems
András Széli, B. A. Steves, A. E. Roy:
Numerical Investigation of the Caledonian Problem
Extragalactic Astronomy
Sándor Frey and László Mosoni:
VLBI imaging of weak extragalactic radio sources
Zsuzsanna Győry:
Model Galaxy Spectra and Photometric Redshift Estimation
Csaba Kiss:
The Cosmic Far-infrared Background
László Mosoni:
1546+027: high resolution radio structure of a compact quasar
Zsolt Paragi:
The radio colour-colour diagram of Van der Laan Bubbles
Interstellar Matter
Zoltán Kiss and L. Viktor Tóth:
Cold cloud cores in the Cepheus Flare region
Vera Könyves and Csaba Kiss:
The large scale structure of the ISM in the 2nd and 3rd GQs
Attila Moór and Csaba Kiss:
Supershell around Cas OB5
Variable Stars
Tamás Borkovits and Szilárd Csizmadia:
Period Variations in IM Aurigae
Szilárd Csizmadia and László Patkós:
A new distance determination with W UMa-stars
Zoltán Csubry:
Time-frequency Analysis of Variable Star Light Curves
Zsolt Kővári:
Photometric Cycles and Starspot Tracking on LQ Hya
Miklós Pócs:
Period changes of high-amplitude δ Scuti stars
Gábor Ribárik:
Analysis of multicolor light curves of active star
Make mission impossible feasible: The experience of a multidisciplinary team providing treatment for alcohol use disorder to homeless individuals
No full textAim: People experiencing homelessness are often excluded from treatment programs for alcohol use disorder (AUD). The goal of this study was to describe the impact of a multidisciplinary treatment program on alcohol consumption and social reintegration in individuals with AUD experiencing homelessness. Methods: Thirty-one individuals with AUD experiencing homelessness were admitted to an inpatient unit for 5–6 days for clinical evaluation and to treat potential alcohol withdrawal syndrome. A group of volunteers, in collaboration with the Community of Sant’Egidio, provided social support aimed to reintegrate patients. After inpatient discharge, all patients were followed as outpatients. Alcohol intake (number drinks/day), craving and clinical evaluation were assessed at each outpatient visit. Biological markers of alcohol use were evaluated at enrollment (T0), at 6 months (T1) and 12 months (T2). Results: Compared with T0, patients at T1 showed a significant reduction in alcohol consumption [10 (3–24) vs 2 (0–10); P = 0.015] and in γ-glutamyl-transpeptidase [187 (78–365) vs 98 (74–254); P = 0.0021]. The reduction in alcohol intake was more pronounced in patients with any housing condition [10 (3–20) vs 1 (0–8); P = 0.008]. Similarly, compared with T0, patients at T2 showed significant reduction in alcohol consumption [10 (3–24) vs 0 (0–15); P = 0.001], more pronounced in patients with any housing condition [10 (3–20) vs 0 (0–2); P = 0.006]. Moreover, at T2 patients showed a significant reduction in γ -glutamyl-transpeptidase [187 (78–365) vs 97 (74–189); P = 0.002] and in mean cell volume [100.2 (95–103.6) vs 98.3 (95–102); P = 0.042]. Conclusion: Patients experiencing homelessness may benefit from a multidisciplinary treatment program for AUD. Strategies able to facilitate and support their social reintegration and housing can improve treatment outcomes
Potentiometric studies on interactions of α-L-glutamic acid oligomers with Cu(II) in aqueous solutions
No full textInternational audienc
Madelung's disease and acute alcoholic hepatitis: case report and review of literature
No full textN/
- …
