Statements of Pliny the younger about health and diseases

The article describes the selected statements about health and illnesses from «Letters of Pliny the Younger», an ancient Roman politician and writer. Pliny the Younger considers health as one of the most important human benefits. He did not separate the health from the soul and the health from the body. Despite the fact that Pliny considers the climate influence on the human condition to be the main one, he also notes the human qualities, without which it is impossible to maintain health – patience, temperance and moderation in everything. According to Pliny, all diseases must be endured steadily, using the same qualities. In Ancient Rome, people took care of their health and well-being. Pliny the Younger's advice on how to maintain health and how to relate to illnesses is useful to us in our timeВ статье описываются отобранные высказывания о здоровье и болезнях из «Писем Плиния Младшего» – древнеримского политического деятеля и писателя. Здоровье Плиний Младший считает одним из важнейших благ человека. Он не отделял друг от друга здоровье души и здоровье тела. Несмотря на то, что Плиний главным считает влияние климата на состояние человека, он отмечает и качества человека, без которых невозможно сохранить здоровье, терпение, воздержание и умеренность во всем. Все болезни по совету Плиния, нужно стойко переносить, используя те же качества. В Древнем Риме люди заботились о своём здоровье и благополучии. Советы Плиния Младшего о том, как сохранить здоровье и как относиться к болезням, полезны нам и в наше время

Ionization by bulk heating of electrons in capacitive radio frequency atmospheric pressure microplasmas

Electron heating and ionization dynamics in capacitively coupled radio frequency (RF) atmospheric pressure microplasmas operated in helium are investigated by Particle in Cell simulations and semi-analytical modeling. A strong heating of electrons and ionization in the plasma bulk due to high bulk electric fields are observed at distinct times within the RF period. Based on the model the electric field is identified to be a drift field caused by a low electrical conductivity due to the high electron-neutral collision frequency at atmospheric pressure. Thus, the ionization is mainly caused by ohmic heating in this "Omega-mode". The phase of strongest bulk electric field and ionization is affected by the driving voltage amplitude. At high amplitudes, the plasma density is high, so that the sheath impedance is comparable to the bulk resistance. Thus, voltage and current are about 45{\deg} out of phase and maximum ionization is observed during sheath expansion with local maxima at the sheath edges. At low driving voltages, the plasma density is low and the discharge becomes more resistive resulting in a smaller phase shift of about 4{\deg}. Thus, maximum ionization occurs later within the RF period with a maximum in the discharge center. Significant analogies to electronegative low pressure macroscopic discharges operated in the Drift-Ambipolar mode are found, where similar mechanisms induced by a high electronegativity instead of a high collision frequency have been identified

Interface Phonons and Polaron Effect in Quantum Wires

The theory of large radius polaron in the quantum wire is developed. The interaction of charge particles with interface optical phonons as well as with optical phonons localized in the quantum wire is taken into account. The interface phonon contribution is shown to be dominant for narrow quantum wires. The wave functions and polaron binding energy are found. It is determined that polaron binding energy depends on the electron mass inside the wire and on the polarization properties of the barrier material

Experimental benchmark of kinetic simulations of capacitively coupled plasmas in molecular gases

International audienceWe discuss the origin of uncertainties in the results of numerical simulations of low-temperature plasma sources, focusing on capacitively coupled plasmas. These sources can be operated in various gases/gas mixtures, over a wide domain of excitation frequency, voltage, and gas pressure. At low pressures, the non-equilibrium character of the charged particle transport prevails and particle-based simulations become the primary tools for their numerical description. The particle-in-cell method, complemented with Monte Carlo type description of collision processes, is a well-established approach for this purpose. Codes based on this technique have been developed by several authors/groups, and have been benchmarked with each other in some cases. Such benchmarking demonstrates the correctness of the codes, but the underlying physical model remains unvalidated. This is a key point, as this model should ideally account for all important plasma chemical reactions as well as for the plasma-surface interaction via including specific surface reaction coefficients (electron yields, sticking coefficients, etc). In order to test the models rigorously, comparison with experimental ?benchmark data? is necessary. Examples will be given regarding the studies of electron power absorption modes in O 2 , and CF 4 ?Ar discharges, as well as on the effect of modifications of the parameters of certain elementary processes on the computed discharge characteristics in O 2 capacitively coupled plasmas

Electron power absorption dynamics in capacitive radio frequency discharges driven by tailored voltage waveforms in CF4

The power absorption dynamics of electrons and the electrical asymmetry effect in capacitive radio-frequency plasmas operated in CF4 and driven by tailored voltage waveforms are investigated experimentally in combination with kinetic simulations. The driving voltage waveforms are generated as a superposition of multiple consecutive harmonics of the fundamental frequency of 13.56 MHz. Peaks/valleys and sawtooth waveforms are used to study the effects of amplitude and slope asymmetries of the driving voltage waveform on the electron dynamics and the generation of a DC self-bias in an electronegative plasma at different pressures. Compared to electropositive discharges, we observe strongly different effects and unique power absorption dynamics. At high pressures and high electronegativities, the discharge is found to operate in the drift-ambipolar (DA) heating mode. A dominant excitation/ionization maximum is observed during sheath collapse at the edge of the sheath which collapses fastest. High negative-ion densities are observed inside this sheath region, while electrons are confined for part of the RF period in a potential well formed by the ambipolar electric field at this sheath edge and the collapsed (floating potential) sheath at the electrode. For specific driving voltage waveforms, the plasma becomes divided spatially into two different halves of strongly different electronegativity. This asymmetry can be reversed electrically by inverting the driving waveform. For sawtooth waveforms, the discharge asymmetry and the sign of the DC self-bias are found to reverse as the pressure is increased, due to a transition of the electron heating mode from the α-mode to the DA-mode. These effects are interpreted with the aid of the simulation results

Multi-phonon transitions in II-VI quantum dot

The intensity of polaron exciton absorption in a spherical quantum dot is calculated. The localized electrons and holes are shown to interact with long-wavelength phonons with wave vectors $q \approx 1/R$, R being the radius of the dot. In the case of strong electron-phonon interaction, the polaron effect results in multiple phonon replicas of exciton optical transition. The broadening of different phonon replicas is shown to be less than their separation