The Boltzmann distribution and molecular gases

“The Boltzmann distribution and molecular gases” explains why an “ordinary” gas has its molecules Boltzmann-distributed. The most concentrated Fermi–Dirac gas, helium 3 at its boiling point, is still in a “dilute limit”, dilute enough to be approximately Boltzmann. Similarly, the most concentrated Bose–Einstein gas, helium 4 at its boiling point, is also approximately Boltzmann.

PLASMA NEW SELECTIVE PROPERTIES FOR EFFICIENT USE IN ELECTRONICS AND TELECOMMUNICATIONS

In terms of active and passive electronic counteraction, detection of geophysical phenomena of artificial andnatural origin is becoming increasingly important. Discovering new properties of plasma enables to improve the informationcomponent of radio signals more effectively and use the obtained properties in related fields. Elementary processes in thelongitudinal and transverse directions of the discharge, depending on natural and artificial conditions, under different typesof gaseous medium used; at different gas pressures and different pulse-periodic application of an electric field is studied inthe article. The difference of discharge properties in inert and molecular gases with different designs and electrodes of thelaboratory device is shown. It is established that the change of functional purpose between the cathodes and the anodes doesnot change the shape of the discharge. The presence of ambipolar diffusion of charge carriers acting on a large area of plasmawas determined. Partial charge carrier homogeneity has been established, which is observed only along the plasma surface,and homogeneity is violated in the perpendicular direction. The difference in energy input in the discharge, depending on thedesign of the electrodes other things being equal is determined. The identified properties of plasma enable them to be usedmore effectively for practical implementation in the field of electronics and telecommunications and other industries.

Thermochemistry of Combustion in Polyvinyl Alcohol + Hydroxylammonium Nitrate

A mixture of polyvinyl alcohol (PVA) and hydroxylammoniun nitrate (HAN) forms a gummy solid known as a plastisol, which is ionically conducting. When an electrostatic potential of 200 V DC is applied across the plastisol, it ignites. Combustion ceases upon removal of the applied voltage. The products of PVA + HAN combustion are known to include the molecular gases carbon monoxide, carbon dioxide, water, nitrogen, and hydrogen. When the electric field within the plastisol is spatially uniform, combustion occurs preferentially at the anode. The fact that HAN is an ionic conductor suggests that the mechanism of combustion is electrolytic in origin. Consistent with the preference for combustion at the anode and the known gaseous products, we consider two reaction mechanisms. One involves atomic oxygen as the oxidizing agent at the anode and hydroxyl radical as the oxidizing agent at the cathode. The other involves ozone as the oxidizing agent at the anode and hydrogen peroxide as the oxidizing agent at the cathode. Each mechanism is applied to a scenario where the products are rich in the carbon oxides and to a second scenario where the products are poor in the carbon oxides. In the rich case, the heat of the overall reaction is −808.33 kJ per mole of HAN consumed and the electrical energy is converted to thermal energy with an efficiency of 4.2%. In the poor case, the corresponding figures are −567 kJ per mole of HAN and efficiency is 2.9%. The combustion reactions at the electrodes are uniformly exothermic with the exception of the reaction involving hydrogen peroxide at the cathode. When the products are poor in the carbon oxides, this reaction is actually endothermic.

The effect of hydrophobic gases on the water fleaDaphnia magna

It is well known that some hydrophobic atomic and molecular gases provoke anaesthetic effects in mammal animals. Depending on the gas, there is a Minimum Alveolar Concentration (MAC) to produce anaesthesia. The gas enters in the lungs, dissolve in the blood and reaches the brain. Where are the targets and which are the action mechanisms are subjects not fully understood yet. Very recently, we reported the effects of local anaesthetics on the swimming behaviour of the water fleaDaphnia magna(STOTEN691, 278-283, 2019). Our aim now is to report new studies on the behaviour of this aquatic invertebrate in the presence of three hydrophobic gases: xenon, nitrous oxide and krypton. However, if local anaesthetics easily dissolve in water, these gases do not. Therefore, we designed a chamber to dissolve the gases using pressures up to 50 atmospheres. Simultaneously, we were able to measure in real time the response of the animals through transparent windows able to support such high pressures. Xenon and nitrous oxide effectively induce lack of movement in the daphnids. The effective pressures EP50for xenon and nitrous oxide were and 5.2 atmospheres, respectively. Krypton does not present clear effects on the motile suppression, even after the exposure to 44 atmospheres. Our findings provide insight on the physiological effects important gases used in human medicine produce in aquatic invertebrate animals considered as potential models to study anesthesia.