607 research outputs found
A computationally efficient inorganic atmospheric aerosol phase equilibrium model (UHAERO)
A variety of thermodynamic models have been developed to predict inorganic gas-aerosol equilibrium. To achieve computational efficiency a number of the models rely on a priori specification of the phases present in certain relative humidity regimes. Presented here is a new computational model, named UHAERO, that is both efficient and rigorously computes phase behavior without any a priori specification. The computational implementation is based on minimization of the Gibbs free energy using a primal-dual method, coupled to a Newton iteration. The mathematical details of the solution are given elsewhere. The model also computes deliquescence and crystallization behavior without any a priori specification of the relative humidities of deliquescence or crystallization. Detailed phase diagrams of the sulfate/nitrate/ammonium/water system are presented as a function of relative humidity at 298.15 K over the complete space of composition
A new inorganic atmospheric aerosol phase equilibrium model (UHAERO)
A variety of thermodynamic models have been developed to predict inorganic gas-aerosol equilibrium. To achieve computational efficiency a number of the models rely on a priori specification of the phases present in certain relative humidity regimes. Presented here is a new computational model, named UHAERO, that is both efficient and rigorously computes phase behavior without any a priori specification. The computational implementation is based on minimization of the Gibbs free energy using a primal-dual method, coupled to a Newton iteration. The mathematical details of the solution are given elsewhere. The model computes deliquescence behavior without any a priori specification of the relative humidities of deliquescence. Also included in the model is a formulation based on classical theory of nucleation kinetics that predicts crystallization behavior. Detailed phase diagrams of the sulfate/nitrate/ammonium/water system are presented as a function of relative humidity at 298.15 K over the complete space of composition
Relativistic Effects in S-Wave Quarkonium Decay
The decay widths of S-wave quarkonia (\etc,\etb\to \gg{~~and~~}
\J,\U\to\ee) are calculated on the basis of a quasipotential approach. The
nontrivial dependence on relative quark motion of decay amplitude is taken into
consideration via quarkonium wave function. It is shown that relativistic
corrections may be large (10-50 %) and comparable with QCD corrections.Comment: 10 pages, no figure
Physician trainees' decision making and information processing: choice size and Medicare Part D.
Many patients expect their doctor to help them choose a Medicare prescription drug plan. Whether the size of the choice set affects clinicians' decision processes and strategy selection, and the quality of their choice, as it does their older patients, is an important question with serious financial consequences. Seventy medical students and internal medicine residents completed a within-subject design using Mouselab, a computer program that allows the information-acquisition process to be examined. We examined highly numerate physician trainees' decision processes, strategy, and their ability to pick the cheapest drug plan-as price was deemed the most important factor in Medicare beneficiaries' plan choice-from either 3 or 9 drug plans. Before adjustment, participants were significantly more likely to identify the lowest cost plan when facing three versus nine choices (67.3% vs. 32.8%, p<0.01) and paid significantly less in excess premiums (128.51, p<0.01). Compared to the three-plan condition, in the nine-plan condition participants spent significantly less time acquiring information on each attribute (p<0.05) and were more likely to employ decision strategies focusing on comparing alternate plans across a single attribute (search pattern, p<0.05). After adjusting for decision process and strategy, numeracy, and amount of medical training, the odds were 10.75 times higher that trainees would choose the lowest cost Medicare Part D drug plan when facing 3 versus 9 drug plans (p<0.05). Although employing more efficient search strategies in the complex choice environment, physician trainees experienced similar difficulty in choosing the lowest cost prescription drug plans as older patients do. Our results add further evidence that simplifications to the Medicare Part D decision environment are needed and suggest physicians' role in their patients' Part D choices may be most productive when assisting seniors with forecasting their expected medication needs and then referring them to the Medicare website or helpline
Direct air capture technology for carbon removal
Air pollution caused by harmful gases is a global problem. Direct
Air Capture invention created by Carbon Engineering company is a promising
method of cleaning air from toxic gas. The efficient DAC CO2 recycling technology
is presented
DISTRIBUTION OF QT DURATION ACCORDING TO AMBULATORY ECG MONITORING DATA IN PATIENTS WITH HYPERTENSION DEPENDING ON CLINICAL MANIFESTATIONS
The study was carried out to identify the distribution of QTc during ECG AM depending on clinical features of EH in 82 patients. As classified shortened was considered QTс 320 ms and 440 ms. Average, maximum and minimum QTc are registered in every patient during ECG AM. The results confirm low probability of short QTc and demonstrate presence of prolonged QTc in every patient during ECG AM. The largest duration of maximal QTc have adulthood male patients with obesity III st., with low and high circadian index, with II stage and mild EH, with for the first time diagnosed EH and with EH lasting more than 10 years, with mild cardiovascular risk, with diffuse cardiosclerosis, with I and II FC and I and IIA st of HF
Proton polarizability contribution to the hydrogen hyperfine splitting
The contribution of the proton polarizability to the hydrogen hyperfine
splitting is evaluated on the basis of modern experimental and theoretical
results on the proton polarized structure functions. The value of this
correction is equal to 1.4 ppm.Comment: 11 pages, LaTeX2.09, 7 figures, uses linedraw.sty, psfig.sty,
epsf.st
РАЗРАБОТКА И ИССЛЕДОВАНИЯ СВЕРХМОЩНОГО ТИРИСТОРНОГО МОДУЛЯ ДЛЯ МОЩНОГО ЧАСТОТНО-РЕГУЛИРУЕМОГО ЭЛЕКТРОПРИВОДА
This report presents developed fast thyristor module with voltage 2600 V and mean on-state current 1000 A with silicon wafers 3'' for inverter applications in power variable-frequency driveПредставлены результаты разработки тиристорного модуля с повышенным быстродействием на напряжение 2600 В и средний ток в открытом состоянии 1000 A с диаметром кремниевой структуры 3 дюйма для применения в преобразователях на основе автономного инвертора тока мощного частотно-регулируемого электроприводаНаведено розробки тиристорного модулю з підвищеною швідкодією на напругу 2600 В і середній струм у відкритому стані 1000 А з діаметром кремнієвої структури 3 дюйми для застосування в перетворювачах на основі автономного інвертора току потужного частотно-регулюваного електроприводу
Proton polarizability effect in the Lamb shift of the hydrogen atom
The proton polarizability correction to the Lamb shift of electronic and
muonic hydrogen is calculated on the basis of isobar model and experimental
data on the structure functions of deep inelastic lepton-nucleon scattering.
The contributions of the Born terms, vector-meson exchanges and nucleon
resonances are taken into account in the construction of the photoabsorption
cross sections for transversely and longitudinally polarized virtual photons
sigma_{T,L}.Comment: 11 pages, 3 figure
Time evolution of stimulated Raman scattering and two-plasmon decay at laser intensities relevant for shock ignition in a hot plasma
Laser–plasma interaction (LPI) at intensities 1015–1016 W cm2 is dominated by parametric instabilities which can be
responsible for a significant amount of non-collisional absorption and generate large fluxes of high-energy nonthermal
electrons. Such a regime is of paramount importance for inertial confinement fusion (ICF) and in particular for the
shock ignition scheme. In this paper we report on an experiment carried out at the Prague Asterix Laser System (PALS)
facility to investigate the extent and time history of stimulated Raman scattering (SRS) and two-plasmon decay (TPD)
instabilities, driven by the interaction of an infrared laser pulse at an intensity 1:2 1016 W cm2 with a 100 mm
scalelength plasma produced from irradiation of a flat plastic target. The laser pulse duration (300 ps) and the high
value of plasma temperature (4 keV) expected from hydrodynamic simulations make these results interesting for a
deeper understanding of LPI in shock ignition conditions. Experimental results show that absolute TPD/SRS, driven at
a quarter of the critical density, and convective SRS, driven at lower plasma densities, are well separated in time, with
absolute instabilities driven at early times of interaction and convective backward SRS emerging at the laser peak and
persisting all over the tail of the pulse. Side-scattering SRS, driven at low plasma densities, is also clearly observed.
Experimental results are compared to fully kinetic large-scale, two-dimensional simulations. Particle-in-cell results,
beyond reproducing the framework delineated by the experimental measurements, reveal the importance of filamentation
instability in ruling the onset of SRS and stimulated Brillouin scattering instabilities and confirm the crucial role of
collisionless absorption in the LPI energy balance
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