Type-I superconductivity in ScGa3 and LuGa3 single crystals

We present evidence of type-I superconductivity in single crystals of ScGa3 and LuGa3, from magnetization, specific heat, and resistivity measurements: low critical temperatures Tc = 2.1-2.2 K; field-induced secondto first-order phase transition in the specific heat, critical fields less than 240 Oe; and low Ginzburg-Landau coefficients {\kappa} approx 0.23 and 0.30 for ScGa3 and LuGa3, respectively, are all traits of a type-I superconducting ground state. These observations render ScGa3 and LuGa3 two of only several type-I superconducting compounds, with most other superconductors being type II (compounds and alloys) or type I (elemental metals and metaloids).Comment: 5 pages, 6 figure

Law and politics of advisory opinions at the ICJ: The attitudes of the Soviet Union/Russia and the U.S.

https://www.ester.ee/record=b543923

Grain Import Dependency and Food Security in the South Caucasus

Although food security has improved during the transition period, the issue is still prevalent in the countries of the South Caucasus, which are heavily depending on wheat, the most important staple crop in the region, imported from Russia, and to a limited degree from Kazakhstan and Ukraine. Due to their favorable location next to the largest wheat exporting region, trade costs play a relatively small role and wheat markets in Armenia, Azerbaijan and Georgia are relatively well integrated with the Black Sea export market. Nevertheless, Armenia has the least diversified wheat imports among the South Caucasian countries due to its closed border with Azerbaijan. Despite the well-integrated markets, wheat imports and thus food security remain challenged by repeated restriction of wheat exports by the governments of Russia, Kazakhstan and Ukraine, most recently implemented as crisis policy during the COVID-19 pandemic

Thermotunnel refrigerator with vacuum/insulator tunnel barrier: A theoretical analysis

The authors use two insulator layers in thermotunnel refrigerator to modify the shape of the tunneling barrier so that electrons with high kinetic energy pass it with increased probability. Theoretical analysis show that the overall tunneling current between the electrodes contains an increased number of high kinetic energy electrons and a reduced number of low energy ones, leading to high efficiency. The particular case of vacuum gap and solid insulator layer is calculated using digital methods. Efficiency remains high in the wide range of the emitter electric field. The cooling coefficient is found to be as high as 40%-50% in the wide range of the emitter electric field.Comment: 9 pages, 3 figure