Applications Aspects of the Diffusion of Slow Electrons in the Ionospheric Gases

The paper presents the results of precise of the calculations of the diffusion of slow electrons in ionospheric gases, such as, (Argon – Hydrogen mixture, pure Nitrogen and Argon – Helium – Nitrogen) in the presence of a uniform electric field and temperature 300 Kelvin. Such calculations lead to the value Townsend's energy coefficient (KT) as a function of E/P (electric field strength/gas pressure), electric field (E), electric drift velocity (Vd), momentum transfer collision frequency ( ), energy exchange collision frequency ( ) and characteristic energy (D/?). The following physical quantities are deduced as function s E/P: mean free path of the electrons at unit pressure, mean energy lost by an electron per collision, mean velocity of agitation and the collisional cross-section of the molecules. The results are presented graphically and in tabular form. This results appeared a good agreement with the experimental data

Mean Drift Length During a Semi Wave of the CW Radio-Frequency Field

In this work we study mean drift length during a semi wave of the CW radiofrequency field the behavior of the diffusion particles in the pure Helium gas whose plays important role in production of the lam ps such as glow lamps and gas lasers through the calculation of the transport parameters which are w, μ, and D by solving numerically transport equation and feeding it to computer program which is construction to calculate the following parameters: E/P300, S, DN, Dp, n, c , l, w, a, SE, (fn1P), (fn1P)-1, w/p and p/w for energy ranges 0.121´10-18 £ E/N £ 0.303 ´10-16 V.cm2 at temperature 300°K. These parameters represented as functions for their variables whose shows a good agreement with experimental and theoretical data

Study of Reactivity Effect on Reactor Power by Using the Neutronic- Thermohydrolic Coupling

The study deals with reactivity insertion linear and non linear and/or Ramp reactivity expressed as a polynomial in time in the presence of two Feedback mechanisms, using the neutronic-thermohydraulic coupling in order to predict the neutron behavior as a function of time in terms of reactor power. Also, a comparative study has been achieved in the case of the presence of the feedback mechanisms. Insertion of Ramp reactivities in terms of polynomial in time to study the behavior of power and reactivity as a function of time in the presence of two feedback mechanisms (fuel and coolant) has been carried out and the results are displayed as plots, and showed this results corresponding with international results. The present study shows that the simulation of neutron time behavior is a vital tool to predict the behavior of reactivity and/or power as a function of time in case of insertion of negative or positive and/or Ramp reactivities in power reactor core for the case including feedback mechanism. Also, the simulation may be considered a unique technique to predict unexpected incident and/or accident that may occur in reactor power core in case of the availability of accurated input data

Comprehensive analysis of heat transfer and pressure drop in square multiple impingement jets employing innovative hybrid nanofluids

This study presents a comprehensive analysis of heat transfer and pressure drop characteristics in square multiple impingement jets utilising a novel class of hybrid nanofluids. This study goes beyond the usual vertical impingement method by looking at the use of oblique impingement in a multiple impinging jet configuration with a hybrid nanofluid. Al2O3–Cu/water with different volume fractions () such as 0.1%, 0.33%, 0.75%, and 1.0% are employed as a working fluid. The purpose of the study is to clarify the impact of the jet angle (β), the jet Reynolds number (Re), extended jet height ), and different volume fraction () on the heat transfer behaviours of the curved target surface. The jet Reynolds number varies from 8000 to 24,000, and five different jet angles (β = 15 , 30°, 45°, 60°, 90 ) and three extended jet heights  = 0.2H, 0.4H, and 0.6H) are adopted. Outcomes disclosed that the highest values of Re and  greatly led to an increase in heat transfer rate and pressure drop of the system. It is uncovered that the heat transfer rate of binary hybrid nanofluids enhances with increasing volume fraction from for all jet angles and Re. Results also exposed that the angle of jet, which is 45°, gives a higher Nusselt number compared to other angles proposed in this study, and the maximum boost reaches 35%. Besides, despite the fact that reducing the height of the extended jet yields enhanced heat transfer rates in comparison to other methods, it concurrently results in an elevation in pressure drop. Finally, this research yielding insights that can be applied to improve the efficiency of heat transfer systems in practical applications.Validerad;2024;Nivå 1;2024-04-09 (joosat);Full text license: CC BY-NC-ND</p