Азот-содержащие вещества в снеге районов падения ступеней ракеты-носителя «Протон» в 2009 – 2019 гг.

Азот-содержащие вещества в снеге районов падения ступеней ракеты-носителя «Протон» в 2009 – 2019 гг.

Иван Семенков

Abstract

Для оценки поступления компонентов ракетного топлива и продуктов их трансформации в ландшафты в результате пусков с космодрома Байконур в 2009 – 2019 гг. обобщены данные по 1477 пробам снега, собранным в районах падения ступеней ракеты-носителя (РН) «Протон» в Центральном Казахстане, юго-востоке Западной Сибири и Северо-Восточном Алтае. На 18 обследованных местах падения (МП) достоверное загрязнение снега от ракетно-космической техники установлено только на расстоянии не более 10 м от фрагментов ступени в безлюдных территориях районов падения Центрального Казахстана, куда проливаются компоненты ракетного топлива из фрагментов первой ступени РН «Протон». Концентрация несимметричного диметилгидразина (НДМГ) достигала 2.5 г/л, нитрозодиметиламина (НДМА) – 0.24 г/л, NO₃^– – 236 г/л, NH₄⁺– 0.67 г/л, NO₂^– – 0.48 г/л, тетраметилтетразена (ТМТ) – 5.5 мг/л, формальдегида – 6.0 мг/л. Величина рН снега варьировала от 0.9 ед. от загрязнения N₂O₄ до 10.3 ед. от загрязнения НДМГ при фоновых значениях 5.2–7.7 (10 и 90% персентили). На незагрязненных территориях Центрального Казахстана азотосодержащие соединения в снеге представлены (медиана→90% персентиль в мг/л): NO₃^– (1.6→13.8, n=104), NH₄⁺ (0.3→1.8, n=42) и в меньшей степени NO₂^– (0.0015→0.04, n=104), НДМГ и НДМА не встречаются. Химический состав снега районов падения второй ступени отражает фоновые уровни азотсодержащих соединений природного происхождения и отсутствие компонентов ракетного топлива. На Кетско-Тымской равнине и Северо-Восточном Алтае фоновое содержание (среднее и стандартное отклонение) азотсодержащих веществ уменьшалось от NO₃^– (0.36±0.28 и 0.47±0.59 мг/л) к NO₂^– (0.048±0.016 и 0.027±0.073) и NH₄⁺ (<0.05 и 0.20±0.27).

Keywords

цикл азота, фоновый геохимический мониторинг, загрязнение поверхностных вод,

About the Author

Иван Семенков

МГУ имени М.В.Ломоносова
Russian Federation

References

1. Morokov Yu.N. Modeling the fall in the atmosphere of rocket fuel residues. Vychislitel'nye tekhnologii. Computing technology. 2008, 12 (2): 52-59. [In Russian]

2. Kasimov N.S., Kondrat'ev A.D., Koroleva T.V., Krechetov P.P., Neronov V.V., Popik M.V., Smolenkov A.D., Fadeev A.S., Chernicova O.V., Shpigun O.A. Ekologicheskij monitoring raketno-kosmicheskoj deyatel'nosti (Environmental monitoring of rocket and space activities). Moscow: Restart, 2011: 472 p.

3. Fedorov L.A. Liquid missile propellants in the former Soviet Union. Environmental Pollution. 1999, 105: 157–161.

4. Koroleva T.V., Krechetov P.P., Semenkov I.N., Sharapova A.V., Lednev S.A., Karpachevskiy A.M., Kondratyev A.D., Kasimov N.S. The environmental impact of space transport. Transportation Research Part D: Transport and Environment. 2018, 58: 54–69. doi 10.1016/j.trd.2017.10.013

5. Sharapova A.V., Semenkov I.N., Koroleva T.V., Krechetov P.P., Lednev S.A., Smolenkov A.D. Snow pollution by nitrogen-containing substances as a consequence of rocket launches from the Baikonur Cosmodrome. Science of the Total Environment. 2020, 709: 136072

6. Kenessov B., Alimzhanova M., Sailaukhanuly Y., Baimatova N., Abilev M., Batyrbekova S., Carlsen L., Tulegenov A., Nauryzbayev M. Transformation products of 1,1-dimethylhydrazine and their distribution in soils of fall places of rocket carriers in Central Kazakhstan. Sci. Total Environ. 2012, 427–428:78–85. doi:10.1016/j.scitotenv.2012.04.017

7. Kosyakov D.S., Ul’yanovskii N.V., Bogolitsyn K.G., Shpigun O.A. Simultaneous determination of 1,1-dimethylhydrazine and products of its oxidative transformations by liquid chromatography–tandem mass spectrometry. Int. J. Environ. Anal. Chem. 2014, 94 (12): 1254–1263. doi: 10.1080/03067319.2014.940342.

8. Rodin I.A., Smirnov R.S., Smolenkov A.D., Krechetov P.P., Shpigun O.A. Transformation of unsymmetrical dimethylhydrazine in soils. Eurasian Soil Sci. 2012, 45(4: 386 – 391. doi:10.1134/S1064229312040096

9. Zhubatov Z.K., Kenessov B., Bakaikina N,, Bimaganbetova A.O., Akynbayev N., Bakhytkyzy I. Fast Determination of 1-Methyl-1H-1,2,4-triazole in Soils Contaminated by Rocket Fuel Using Solvent Extraction, Isotope Dilution and GC–MS . Chromatographia. 2016, 79(7–8): 491–499 doi:10.1007/s10337-016-3054-8

10. Kosyakov D.S., Ul’yanovskii N,, Pikovskoi I.I., Kenessov B., Bakaikina N,, Zhubatov Z., Lebedev A.T. Effects of oxidant and catalyst on the transformation products of rocket fuel 1,1-dimethylhydrazine in water and soil. Chemosphere. 2019, 228: 335–344. doi:10.1016/j.chemosphere.2019.04.141

11. Ul'yanovskii N.V., Lakhmanov D.E., Pikovskoi I. I., Falev D.I., Popov M.S., Kozhevnikov A.Yu., Kosyakov D.S. Migration and transformation of 1,1-dimethylhydrazine in peat bog soil of rocket stage fall site in Russian North. Science of The Total Environment. 2020, 726: 138483. doi:10.1016/j.scitotenv.2020.138483

12. Smolenkov A.D., Poputnikova T.O., Smirnov R.S., Rodin I.A., Shpigun O.A.Comparative assessment of toxicity of unsymmetrical dimethyl hydrazine and its decomposition products by bioassay methods. Teoreticheskaya i prikladnaya ekologiya. Theoretical and Applied Ecology. 2013, 2: 85 – 90.

13. Ushakova V.G., Shpigun O.N., Starygin O.I. Features of chemical transformations of UDMH and its behavior in environmental objects. Polzunovskij vestnik. Polzunovsky Bulletin. 2004 (4): 177-184. [In Russian].

14. Ermakov E.I., Panova G.G., Petrova Z.M., Ostapenko N.S., Bojcova L.V. The effect of asymmetric dimethylhydrazine on the state of the soil-plant system. Materialy nauchno-prakticheskoj konferencii RNC «Prikladnaya himiya» (Proc. of the scientific-practical conference of the RSC “Applied Chemistry”). Sank-Peterburg, RNC Prikladnaya himiya, 1996: 15 – 19. [In Russian].

15. Koroleva T.V., Krechetov P.P., Semenkov I.N., Sharapova A.V., Kondrat’ev A.D. Transformation of Chemical Composition of Snow in the Impact Areas of the First Stage of the Expandable Launch System Proton in Central Kazakhstan. Russian Meteorology and Hydrology. 2016. 41 (8): 585-591. doi:10.3103/S1068373916080094

16. Kottek M, Griesler J., Beck C., Rudolf B., Rubel F. World Map of the Köppen-Geiger climate classification updated. Meteorologische Zeitschrift. 2006, 15 (3): 259–263

17. Ekologicheskij pasport rajona padeniya otdelyayushchihsya chastej raket-nositelej №372 i sopredel'nyh territorij (Ecological passport of the region of the fall of the separating parts of launch vehicles No. 372 and adjacent territories), Moscow: Moscow State University, 2013: 60 p.

18. Koroleva T.V., Sharapova A.V., Krechetov P.P. A chemical composition of snow on areas exposed to space-rocket activity (Altai republic). Gigiena i sanitariia. 2017, 96 (5): 432–437.

19. Dolotov A.E., Kuznecov G.V., Nemova T.N. Modeling the process of evaporation of asymmetric dimethylhydrazine in the Earth’s atmosphere. Izvestiya Tomskogo politekhnicheskogo universiteta. News of Tomsk Polytechnic University. 2008, 313 (4): 23 – 25. [In Russian].

20. Sheremet'eva U.M. Modeling of the distribution of toxic fuel components during the operation of liquid rockets. Dissirtation. Tomsk: National Research Tomsk State University, 2006: 149 p. [In Russian].

21. Bulba E., Nemova T., Dyatchina A. The Temperature of the Dimethylhydrazine Drops Moving in the Atmosphere after Depressurization of the Fuel Tank Rockets. MATEC Web of Conferences. 2016, 72: 1–4. doi:10.1051/matecconf/20167201020

22. Koroleva T.V., Chernitsova O.V., Sharapova A.V., Krechetov P.P., Puzanov A.V., Gorbachev I.V.. Soil and Geochemical Characteristics of Mountain and Tundra Landscapes in Impact Zones Used for Landing Separated Parts of Launch Vehicles. Contemporary Problems of Ecology. 20147 (2): 151-157. doi: 10.1134/S1995425514020085

23. Koroleva T.V., Sharapova A.V., Kadetov N.G., Chernitsova O.V. Ecologo-geochemical investigations on territories experiencing the effects from rocket and space activity (Northwestern Altai). Geography and Natural Resources. 2015 36(1): 54–61. doi: 10.1134/S1875372815010084

24. Mrvić, V., Kostić-Kravljanac, L., Čakmak, D., Sikirić, B., Brebanović, B., Perović, V., Nikoloski, M. Pedogeochemical mapping and background limit of trace elements in soils of Branicevo Province (Serbia). J. Geochemical Explor. 2011, 109 (1 – 3): 18–25. doi:10.1016/j.gexplo.2010.09.005.

25. Ul'yanovskii N.V., Lakhmanov D.E., Pikovskoi I. I., Falev D.I., Popov M.S., Kozhevnikov A.Yu., Kosyakov D.S. Data on the spatial distribution of 1,1-dimethylhydrazine and its transformation products in peat bog soil of rocket stage fall site in Russian North. Data in Brief. 2020,30: 105614. doi:10.1016/j.dib.2020.105614

26. Aber J., McDowell W., Nadelhoffer K., Magill A., Berntson G., Kamakea M., McNulty S., Currie W., Rustad L., Fernandez I. Nitrogen Saturation in Temperate Forest Ecosystems. Bioscience. 1998, 48 (11): 921 – 934. doi:10.2307/1313296

27. Driscoll C., Whitall D., Aber J., Boyer E., Castro M., Cronan C., Goodale C., Groffman P., Hopkinson C., Lambert K., Lawrence G., Ollinger S. Nitrogen pollution: Sources and consequences in the U.S. Northeast. Environment. 2003, 45 (7): 8 – 22. doi:10.1080/00139150309604553

28. Selman M., Greenhalgh S. Eutrophication: Sources and drivers of nutrient pollution. Renewable Resources Journal. 2010, 26(4): 19-26.

29. Suddick E.C., Whitney P., Townsend A.R., Davidson E.A. The role of nitrogen in climate change and the impacts of nitrogen-climate interactions in the United States: Foreword to thematic issue. Biogeochemistry. 2013, 114: 1–10. doi:10.1007/s10533-012-9795-z

30. Onuchin A.A., Burenina T.A., Zubareva O.N., Trefilova O.V., Danilova I.V. Pollution of snow cover in the impact zone of enterprises in Norilsk Industrial Area. Contemporary Problems of Ecology. 2014. 7(6): 714-722. doi: 10.1134/S1995425514060080

31. Dinu M., Moiseenko T., Baranov D. Snowpack as indicators of atmospheric pollution: the example of the Valday Upland. Atmosphere. 2020, 462 (11). doi:10.3390/atmos11050462

32. Polesello S., Comi M., Guzzella L., Marinoni A., Pecci M., Roscioli C., Smiraglia C., Tartari G., Teti P., Valsecchi S., Vuillermoz E. 28 Chemical composition of fresh snow in the Himalaya and Karakoram. Dev. Earth Surf. Process. 2007, 10: 251–262. doi:10.1016/S0928-2025(06)10028-0

33. Schettler G., Shabunin A., Kemnitz H., Knoeller K., Imashev S., Rybin A. Seasonal and diurnal variations in dust characteristics on the northern slopes of the Tien Shan – Grain-size, mineralogy, chemical signatures and isotope composition of attached nitrate. J. Asian Earth Sci. 2014, 88: 257–276. doi:10.1016/j.jseaes.2014.03.019

34. Wake C.P., Mayewski P.A., Spencer M.J. A review of central Asian glaciochemical data. Ann. Glaciol. 1990, 14: 301 – 306. doi:10.3189/S026030550000879X

35. Informacionnyj byulleten' o sostoyanii okruzhayushchej sredy Respubliki Kazahstan (The newsletter on the state of the environment of the Republic of Kazakhstan). 2017, 9 (215): 188 p. [In Russian].

36. Honrath R.E., Guo S., Peterson M.C., Dziobak M.P., Dibb J.E., Arsenault M.A. Photochemical production of gas phase NOx from ice crystal NO3–. J. Geophys. Res. Atmos. 2000, 105 (D19): 24183–24190. doi:10.1029/2000JD900361

37. Jacobi H.W., Kleffmann J., Villena G., Wiesen P., King M., France J., Anastasio C., Staebler R. Role of nitrite in the photochemical formation of radicals in the snow. Environ. Sci. Technol. 2014, 48 (1): 165–172. doi:10.1021/es404002c

38. Van Dam B., Helmig D., Toro C., Doskey P., Kramer L., Murray K., Ganzeveld L., Seok B. Dynamics of ozone and nitrogen oxides at Summit, Greenland: I. Multi-year observations in the snowpack. Atmos. Environ. 2015, 123 (Part A): 268–284. doi:10.1016/j.atmosenv.2015.09.060

39. Warneck P., Wurzinger C. Product quantum yields for the 305-nm photodecomposition of NO3- in aqueous solution. J. Phys. Chem. 1988, 92 (22): 6278–6283. doi: 10.1021/j100333a02

40. Zhinzhakova L.Z., Gazaev M.A., Atabieva F.A. Study of the chemical composition of the snow cover on the territory of the Kabardino-Balkarian State High Mountain Nature Reserve. Izvestiya Kabardino-Balkarskogo nauchnogo centra RAN. News of the Kabardino-Balkarian Scientific Center of the RAS. 2009, 1 (27): 125–130. [In Russian].

41. Filippa G., Freppaz M., Williams M.W., Zanini E. Major element chemistry in inner alpine snowpacks (Aosta Valley Region, NW Italy). Cold regions science and technology. 2010, 64(2. P 158–166. doi: 10.1016/j.coldregions.2010.07.005

42. Nriagu J.O., Lawson G., Wong H.K.T., Cheam V. Dissolved trace metals in lakes Superior, Erie, and Ontario. Environ. Sci. Technol. 1996, 30: 178–187. doi: 10.1021/es950221i

43. Obzor sostoyaniya i zagryazneniya okruzhayushchej sredy v Rossijskoj Federacii za 2014 god (Review of the state and environmental pollution in the Russian Federation for 2014). Moscow: Federal Service for Hydrometeorology and Environmental Monitoring (Roshydromet), 2015: 199 p. [In Russian].

44. Свистов П.Ф, Талаш А.С., Семенец Е.С. О пространственно-временных изменениях кислотности атмосферных осадков. Климат и Природа. – 2016, 2 (19): 14–26.

45. Svistov P.F., Pershina N.A., Pavlova M.T. The phenomenon of acidity and chemical composition of precipitation in the Central Arctic. Mezhdunarodnyj zhurnal eksperimental'nogo obrazovaniya. International Journal of Experimental Education. 2015, 3 (2): 255.

46. Uvarova V.I. Quality characteristics of surface and groundwater in the Kondinsky Lakes Natural Park. Vestnik ekologii, lesovedeniya i landshaftovedeniya. Bulletin of ecology, forestry and landscape science. 2009, 9: 203 – 212. [In Russian].

47. Gosudarstvennyj doklad «O sostoyanii i ob ohrane okruzhayushchej sredy Rossijskoj Federacii v 2014 godu. (State report “On the State and Environmental Protection of the Russian Federation in 2014). Moscow: Ministry of Natural Resources and Ecology, 2015: 473 p. [In Russian].

48. Saaya CH.E., Ondar H.YU., Ondar U.V. Study of the chemical composition of the snow cover of some sections of the Ubsu-Nur basin. Materialy IV mezhdunarodnoj nauchno-prakticheskoj konferencii molodyh uchenyh, aspirantov i studentov, posvyashchennaya Godu gostepriimstva v Respublike Tyva (Proc. of the IV international scientific-practical conference of young scientists, graduate students and students, dedicated to the Year of Hospitality in the Republic of Tuva). Kyzyl: Tuvan State University, 2016: 191 – 192. [In Russian].

49. Belozertseva I.A., Vorobyeva I.B., Vlasova N.V., Lopatina D.N., Yanchuk M.S. Snow pollution in Lake Baikal water area in nearby land areas. Water Resources. 2017. 44(3): 471-484. doi: 10.1134/S0097807817030046

50. Blinov S.M., Menshikova E.A., Baturin E.N., Ushakova E.S., Zolotarev L.R. On a snow cover composition in the vicinity of the Verkhnekamsky Salt Deposit. Ice and Snow. 2015;55(1):121-128. [In Russian] doi:10.15356/2076-6734-2015-1-121-128

51. Dmitriev O.YU., Puzanov A.V., Sambros V.V., Balykin S.N., Gorbachev I.V., Alekseev I.A., SHesterkin V.P., Savelenok A.N. Ecological assessment of the state of the environment in the areas of the fall of the OH RN, planned for launch from the Vostochny spaceport. Materially II Vserossijskoi nauchno-prakticheskoj konferentsii (Proc. Of the II All-Russian scientific-practical conf). Blagoveshchensk: BGPU, 2013: 192–201. [In Russian].

52. Kozlov A.V., Mironova YU.I., Voroncova A.A., Akaf'eva D.V., Beresnev A.A., Bykov A.S., Davydov V.A., Zykov YA.V., Kalinicheva Z.S., Orekhova A.A. Ecological assessment of the cationic anionic composition and acidity of the snow cover from the territory of the Nizhny Novgorod highways. Успехи современного естествознания. 2018, 6: 78–83.

53. Koreckij V.E. Snow in the big city. Vodoochistka. Vodopodgotovka. Vodosnabzhenie. Water purification. Water treatment. Water supply. 2010, 1 (25): 4–11. [In Russian]

54. Krutskih N.V., Borodulina G.S., Kaznina N.M., Batova Yu.V., Ryazancev P.A., Ahmetova G.V., Novikov S.G., Kravchenko I.Yu. Geoecological basis for the organization of monitoring of the Northern urban areas (for example, Petrozavodsk). Trudy Karel'skogo nauchnogo centra RAN. Proceedings of the Karelian Scientific Center of the RAS. 2016, 12: 52–67. [In Russian]. doi: 10.17076/eco361

55. Lobkina V.A., Gensiorovskij Yu.V., Uhova N.N. Geoecological problems of snow-disposal areas in cities (by the example of Yuzhno-Sakhalinsk). Geoekologiya. Inzhenernaya geologiya. Gidrogeologiya. Geokriologiya. Geoecology. Engineering geology. Hydrogeology. Geocryology. 2016 (6): 510 – 520. [In Russian].

56. Meshkov N.A. Methodological basis for assessing the impact of the effects of rocket and space activities on the health of the population living near the fall regions of the separating parts of launch vehicles. Medline.ru. Rossijskij biomedicinskij zhurnal. Medline.ru. Russian Biomedical Journal. 2009, 10: 57-80. [In Russian]

57. Moskovchenko, D.V, Babushkin, A. G. Peculiarities of formation of chemical composition of snow waters (on example of Khanty-Mansi autonomous district). Earth’s Cryosphere, 2012, 16 (1), 71–81. [In Russian]

58. Pristova T.A., Vasilevich M.I. Chemical composition of snow cover in middle-taiga forest ecosystems in the Komi Republic. Geochemistry International. 2011. 49 (2): 199-206.

59. Prozhorina T.I., YAkunina N.I. Assessment of anthropogenic impact on the urban environment by pollution of the snow cover. Materialy Vserossijskoj nauchno-prakticheskoj konferencii (Proc. of the All-Russian Scientific and Practical Conference). Volgograd: Volgograd State University, 2014: 373–376. [In Russian]

60. Radomskaya V.I., Yusupov D.V., Pavlova L.M., Sergeeva A.G., Borodina N.A. Multivariate statistical analysis of element contents in the snow cover of Blagoveshchensk. Regional'naya ekologiya. Regional ecology. 2018, 2 (52): 15 – 28. [In Russian]. doi:10.30694/1026-5600-2018-2-15-28

61. Sabylina A.V., Efremova T.A. The chemical composition of ice and water under ice of Lake Onega (the case of Petrozavodsk Bay). Led i Sneg. Ice and Snow. 2018. 58 (3): 417–428. [In Russian]. doi: 10.15356/2076-6734-2018-3-417-428.

62. Semenec E.S. Svistov P.F., Talash A.S. The chemical composition of precipitation in the Russian Arctic. Izvestiya Tomskogo politekhnicheskogo universiteta. Inzhiniring georesursov. Bulletin of the Tomsk Polytechnic University. Geo-Resource Engineering. 2017, 328 (3): 27 – 36. [In Russian]

63. Stepanov E.G., Salimova F.A., Fasikov R.M., SHafikov M.A.,Parahin A.A, Muldasheva N.A. The influence of industrial enterprises of the city of Salavat on the pollution of snow, soil and crop products. Fundamental'nye issledovaniya. Basic researchs. 2004 5: 51–54. [In Russian].

64. Trubicina O.P. Analysis of the geoecological state of atmospheric air and precipitation in the North of the Russian Plain according to monitoring data. Vestnik Severnogo (Arkticheskogo) federal'nogo universiteta. Seriya: Estestvennye nauki. Bulletin of the Northern (Arctic) Federal University. Series: Natural Sciences. 2008 3: 35-42. [In Russian]

65. Ushakova E.S., Shchukova I.V. The chemical composition of the snow cover of Perm. Geologiya i poleznye iskopaemye Zapadnogo Urala. Geology and Minerals of the Western Urals. 2017, 17: 232 – 235. [In Russian]

66. Shesterkin V.P., Afanas'eva M.I. The salt composition of the snow cover of Khabarovsk and its environs. Modern problems of regional development. Materialy VII Vserossijskoj nauchnoj konferencii (Proc. of the VII All-Russian Scientific Conference). Birobidzhan: Institute or Complex Analysis of Regional Problems of the Far Eastern Branch of the RAS, 2018: 132 – 134. [In Russian]. doi: 10.31433/978-5-904121-22-8-2018-132-134

67. Yahnin E.YA., Tomilin A.M., Tomilina O.V., Popov B.A. Monitoring of snow cover pollution in the influence zone of Baltelktro JSC battery battery (Kirovsky district of St. Petersburg) in 1993 – 2010. Regional'naya ekologiya. Regional ecology. 2011, 1 – 3: 53 – 60. [In Russian]

68. Pozhitkov R., Moskovchenko D., Soromotin A. Kudryavtsev A., Tomilova E. Trace elements composition of surface snow in the polar zone of northwestern Siberia: the impact of urban and industrial emissions. Environmental Monitoring and Assessment. 2020, 192. doi: 10.1007/s10661-020-8179-4

Supplementary files

	1. текст статьи для слепого рецензирования
	Subject
	Type	Исследовательские инструменты
	Download (131KB)	Indexing metadata

	2. рис.1а
	Subject
	Type	Исследовательские инструменты
	View (4MB)	Indexing metadata

	3. рис.1б
	Subject
	Type	Исследовательские инструменты
	View (7MB)	Indexing metadata

	4. полный текст рукописи
	Subject
	Type	Исследовательские инструменты
	Download (131KB)	Indexing metadata

	5. рис.1в
	Subject
	Type	Исследовательские инструменты
	View (15MB)	Indexing metadata

	6. рис.2
	Subject
	Type	Исследовательские инструменты
	View (2MB)	Indexing metadata

	7. рис.3
	Subject
	Type	Исследовательские инструменты
	Download (13KB)	Indexing metadata

	8. рис.4
	Subject
	Type	Исследовательские инструменты
	View (3MB)	Indexing metadata

For citation: . Ice and Snow. 2021;61(2).

Refbacks

There are currently no refbacks.

This work is licensed under a Creative Commons Attribution 4.0 License.

ISSN 2076-6734 (Print)
ISSN 2412-3765 (Online)

Username
Password