EXPERIMENTS
Study of Compositions for Selective Water Isolation in Gas Wells
Al-Obaidi S.H. 1), Hofmann M.1), Smirnov V.I.1),
Khalaf F.H. 2), Alwan H.H. 2)
1)Mining Institute – Saint Petersburg (Russia)
2)Department of Petroleum Engineering, Knowledge University – Erbil (Iraq)
https://doi.org/10.53656/nat2021-6.04
Abstract. A hydrophobic composition containing water repellents and highly volatile solvents is shown in this study to isolate water from the bottomhole formation zone of gas wells and reduce as much as possible the saturation of pore spaces with water…
SCIENCE AND SOCIETY
Мутации и варианти на коронавируса SARS-CoV-2, причинител на COVID-19
Доц. д-р Лъчезар Карагьозов
Софийски университет „Климент Охридски“
https://doi.org/10.53656/nat2021-6.05
Резюме. През 2020 година коронавирусът SARS-CoV-2 предизвика пандемия с тежки последици за много страни.
FROM THE RESEARCH LABORATORIES
Semiempirical Quantum Chemical and Ab Intio Study of Co(Ii), Ni(Ii),Cu(Ii) and Zn(Ii) Complexes With The Azo Dye Derived From 4-Amino Antipyrine and 2,4-Dihydroxy Acetopheone
Satya Narayan Chaulia
Rajendra (Auto) College (India)
https://doi.org/10.53656/nat2021-6.03
Abstract. Semi-empirical quantum chemical calculation was made to study the nucleophilicity of the ligand and to study the mode of bonding between the ligand and the metal ions.
On the Sound, Produced by a Coin, Rolling In A Balloon
Denitsa Vasileva
Sofia High School of Mathematics “Paisiy Hilendarski” – Sofia (Bulgaria)
https://doi.org/10.53656/nat2021-6.06
Abstract. Balloons may be a thing children love playing with, but they also have different interesting physical properties such as the sound that is produced when something is put inside a balloon…
CURRICULUM MATTERS
Трудни теми в учебната програма по химия от гледна точка на учениците
Калин Чакъров, Александрия Генджова
Софийски университет „Св. Климент Охридски“
https://doi.org/10.53656/nat2021-6.02
Резюме. Химията често се възприема като труден предмет, а начинът, по който учениците възприемат ученето, влияе върху техните резултати…
NEW APPROACHES
Development of the Concept of Entropy: A Simpler Alternative to Carnot Cycle
Prof. Jamil Ahmad
University of Botswana (Botswana)
https://doi.org/10.53656/nat2021-6.01
Abstract. The relationship between entropy and reversible heat and temperature is developed using a simple cycle, in which an ideal gas is subjected to isothermal expansion and compression and heated and cooled between states…
