32 Contents

Volume 32 / C o n t e n t s
1.	Tsvetan Dachev, Jordanka Semkova, Borislav Tomov, Yury Matviichuk, Plamen Dimitrov, Nikolay Bankov, Rositza Koleva, Malina Jordanova, Maxim Litvak, Igor Mitrofanov, Dmitry Golovin Alexander Kozyrev, Alexey Malakhov, Maxim Mokrousov, Anton Sanin, Vladislav Tretyakov, Viacheslav Shurshakov, Victor Benghin, Olga Ivanova COMPARISON OF RADIATION MEASUREMENTS BY BTN AND R3DR INSTRUMENTS OUTSIDE INTERNATIONAL SPACE STATION DOI: https://doi.org/10.3897/arb.v32.e01	5
2.	*Antoaneta Frantzova* CLASSIFICATIONS AND TYPOLOGY OF THE NATURAL AND TRIGGERED TECHNOLOGICAL RISKS ACCORDING TO THE GDP AND PROBABILITY OF OCCURRENCE DOI: https://doi.org/10.3897/arb.v32.e02	21
3.	*Georgi Jelev* WATER SURFACE DYNAMIC’S OF THE STUDENA DAM, PERNIK USING SENTINEL 2A AND 2B SATELLITE DATA DOI: https://doi.org/10.3897/arb.v32.e03	34
4.	*Jordan Tzvetkov* SPATIAL MODELING OF ARCHAEOLOGICAL LANDSCAPES WITH UAV AND DIGITAL PHOTOGRAMMETRY DOI: https://doi.org/10.3897/arb.v32.e04	41
5.	*Stefan Kazakov, Valko Biserkov, Luchezar Pehlivanov, Stoyan Nedkov* TROPHIC STATUS ASSESSMENT OF SMALL TURBID LAKES COMPARING REMOTE SENSING AND IN SITU DATA: CASE STUDY AT LOWER DANUBE FLOODPLAIN DOI: https://doi.org/10.3897/arb.v32.e05	53
6.	*Milen Atanasov* MATHEMATICAL MODEL AND ALGORITHM OF OPERATION OF SYSTEM FOR RELEASE OF LOAD FROM AIRPLANE DOI: https://doi.org/10.3897/arb.v32.e06	64
7.	*Hristina Georgieva* AIRCRAFT NOISE LEVEL CALCULATION DURING TAKE-OFF DOI: https://doi.org/10.3897/arb.v32.e07	75
8.	*Konstantin Metodiev* STEADY FLOW ANALYSIS OF A SLENDER WING BY LIFTING SURFACE METHOD DOI: https://doi.org/10.3897/arb.v32.e08	88
9.	*Dimo Zafirov* LONG ENDURANCE ELECTRIC MULTIROTOR UNMANNED AERIAL VEHICLE DOI: https://doi.org/10.3897/arb.v32.e09	99
10.	*Bogdan Gherman, Oana Dumitrescu, Valeriu Dragan* TRANSONIC FLOW STUDY IN A CENTRIFUGAL COMPRESSOR USING PERFORATED AIRFOILS DOI: https://doi.org/10.3897/arb.v32.e10	110
11.	*Ion Malael, Ioana Octavia Bucur, Valeriu Dragan* 2.5D LES SIMULATION OF AN AIRFOIL SHOCK WAVE REDUCTION BY USING POROUS MEDIA DOI: https://doi.org/10.3897/arb.v32.e11	122
12.	*Svetoslav Zabunov* XZ-SERIES OF UNMANNED AERIAL VEHICLES IN 2020 DOI: https://doi.org/10.3897/arb.v32.e12	134
13.	*Assen Marinov, Georgi Yordanov, Martin Kambushev, Stefan Biliderov, Kiril Kambushev* QUANTITATIVE ASSESSMENT OF PILOTING TECHNIQUE BY FLIGHT DATA RECORDER DOI: https://doi.org/10.3897/arb.v32.e13	152
14.	*Nikolay Gueorguiev, Aleksandar Kolarov, Ilian Iliev* MODULE FOR WIRELESS COMMUNICATION IN AEROSPACE VEHICLES DOI: https://doi.org/10.3897/arb.v32.e14	160
15.	*Oleksandr Minai, Oleg Ivanov, Ihor Siedykh* INFLUENCE OF LONG-TERM STAY OF ELEMENTS OF CAPILLARY INTAKE DEVICES IN LIQUID PROPELLANT COMPONENTS ON THEIR PARAMETERS DOI: https://doi.org/10.3897/arb.v32.e15	175
16.	*Peter Getsov, Tsvetan Tsvetkov, Georgi Sotirov, Iliana Nacheva, Zoya Hubenova, Maria Doneva, Petia Metodieva* APPLICATION OF CRYOTECHNOLOGY IN THE CREATION OF SPACE FOODS FOR CREWS WORKING IN EXTREME CONDITIONS DOI: https://doi.org/10.3897/arb.v32.e16	193
17.	*Adelina Miteva, Valeria Stoyanova* ZEOLITES APPLICATION IN TERRESTRIAL AND SPACE INDUSTRY – A REVIEW DOI: https://doi.org/10.3897/arb.v32.e17	209
18.	Lachezar Filchev, Ioannis Manakos, Garo Mardirossian, Dimitar Dimitrov, Rainer Reuter, Tsveta Srebrova, Lubomira Kraleva, Kalliroi Marini, Andreas Rienow A REVIEW OF EARTH OBSERVATION RESOURCES FOR SECONDARY SCHOOL EDUCATION – PART 1 DOI: https://doi.org/10.3897/arb.v32.e18	224
	*New Books*
	*Boyko Ranguelov* A NEW EDITION OF A BOOK ABAUT THE NATURAL HAZARDS, PREVENTION AND PROTECTION DOI: https://doi.org/10.3897/arb.v32.e19	241