The Parametric Optimization of Voltage Multiplier

The evolutionary model of voltage multiplier parametric optimization which includes 5 diodes and 5 capacitors is reviewed. It executes the transformation of alternating into constant voltage using a five times larger amplitude. The valve work is modelled according to the scheme of an ideal key. The original mathematical model of voltage multiplier which includes additional logical variables is deducted. It aссepts binary meanings 0 and 1, where 0 corresponds to closed valve status and 1 corresponds to open. In order to receive such a model, it is necessary to indicate the amount of open and closed valve combinations. Then for each of them, it is necessary to write the system of differential equations. Comparing them with each other the single differential equation system with additional logical variables is written as a generalization. The evolutional model is used in order to select the capacitor volume meaning. The goal function forecasts two conditions: maximum meaning of output voltage 1 kV and its minimal fluctuations in the stable regime.

Positive experience in laser therapy of patients with polysystemic disorder syndrome with hvdmp using scanning beams through the vagina

Low-intensive laser therapy was carried out on 550 women aged 18 to 33 with syndrome of polysystemic disorders at chronic genital inflammations.Efficiency of frequency movement (301 patients) and stable regime (249 patients) of endovaginal low-intensive laser therapy has been studied by means of complex clinical, functional, instrumental, and laboratory examinations. Movement regime of laser application proved to stimulate sexual visceral reactions improving the state of female organism in case of syndrome of polysystemic disorders. Normalization of the sexualfunction as a result of movement regime in endovaginal laser therapy can be considered as pathogenic influence directed on normalizing and supporting physiological nervous-reflex connections of genital organs with other organs and systems of womens organisms.

Hydrochemical Characterization of Nabeghlavi Underground Mineral Waters

Georgia is rich in groundwater deposits, which renew over time and are characterized by the best indicators of water quality and a stable regime. Groundwater is one of the main natural productive forces of Georgia, which plays an important role in the economic development and export industry. During 2015–2020, chemical composition of the Nabeghlavi mineral waters has been studied by the means of the modern unified methods. Almost all data from previous chemical analyzes have also been retrieved and systematized/collated. Using mathematical statistical analysis, the maximum, minimum, and mean arithmetic values of the major and specific components of water and the empirical deviation from the arithmetic mean have been calculated. Though comparison of the recent and historic data on chemical composition, based on the results of statistical analysis of the major ions, the natural fluctuation limits of the waters and stability of waters from all exploitation drill holes have been shown. According to the chemical composition and total mineralization there are three groups of waters in fresh and low mineralized category. It is shown that chemical composition of water from all exploitation drill holes meets requirements for the natural mineral water category, both the normative document of Georgia and directive of the European Commission.

Analytical calculation of the parameters of light bullets propagating in the tunnel ionization regime

Analytic estimation of the parameters of light bullets formed in the anomalous group dispersion region of transparent dielectrics under conditions of tunneling photoionization was performed. For this purpose, the system of the ordinary differential equations for the laser pulse’s parameters such as amplitude, temporal duration, chirp parameter, temporal delay, frequency shift, radius and curvature were obtained. The stationary solution of this system and conditions of the quasi-stable regime of propagation were found.

AI-Based Well Ranking System for Hydraulic Fracturing Events

We are presenting a new, highly intelligent AI-based ranking system for selecting the most appropriate candidates for well treatment. The system is trained to predict flow rates after hydraulic fracturing (HF) and rank wells by the expected effect of the event with machine learning techniques. We demonstrate a significant effort for preprocessing the available field data to create a dataset for training machine learning (ML) models. The dataset included information about geology, transport and storage properties, depths, oil/liquid rates before fracturing for target and neighboring wells. Each ML model has been trained to predict monthly production of oil and liquid right after fracturing and after flow stabilization. Also, confidence intervals of the prediction have been provided. To study the dynamics of future oil rate decline after HF on a stable regime, we have trained several regression models to make predictions at each future point (6 next months after fracturing). To estimate the effect due to HF, we defined expected production "without fracturing." Typically, wells behave with a stable decline trend of production that is approximated by Arps function. The function is defined before HF, then extrapolated to the period after the event where it shows expected production without fracturing. One may conclude about the effectiveness of HF by calculating areas difference under the extrapolated curve (cumulative production without HF), and ML predicted cumulative production for future six months. Reservoir engineers could calculate these differences for each well and create a ranking list from the highest effect to the lowest. The developed system does this automatically for the required oilfield or its part. Therefore, one may easily define the list of best candidates for HF. Gradient Boosting algorithm has been applied to obtain results. Feature selection and tuning of hyperparameters have been provided with the application of cross-validation technique. To test the developed approach, we have divided the dataset from 8 conventional oil fields at a ratio of four to one. The total dataset included 700+ well interventions. Then we have trained and validated models for flow rate prediction on the major part and tested on the holdout part. For different oil field determination coefficients (R2) and normalized root mean square errors (n-RMSE) for oil rate predictions were around R2=0.8 and n-RMSE=0.35 correspondently. The proposed technique is a new approach for fast, accurate, and objective selection of the candidates for hydraulic fracturing based on real-time state of a field. Such AI-based system could become very handy assistant for reservoir engineer in addition to hydraulic fracturing and hydrodynamic simulators. The presented solution computationally efficient and does not require detailed information about HF design.

Towards the Stable Evolution of Dendrites in the Case of Intense Convection in the Melt

The solid-phase pattern in the form of a dendrite is one of the frequently met structures produced from undercooled liquids. In the last decades, an analytical approach describing the steady-state crystal growth in the presence of conductive heat and mass transport has been constructed. However, experimental works show that crystal patterns frequently grow in the presence of convection. In this paper, a theoretical description based on convective heat and solute concentration transport near the solid/liquid phase interface is developed. The stable regime of crystallization in the presence of vigorous convection near the steady-state crystal vertex is studied. The stability analysis, determining the stable growth mode, and the undercooling balance law have been applied to deduce the stable values for the growth rate and tip diameter. Our analytical predictions (with convective transport) well describe experimental data for a small melt undercooling. Moreover, we compare both convective and conductive mechanisms in the vicinity of the crystal vertex. Our theory shows that convective fluxes substantially change the steady-state growth of crystals.

A Magnetospheric Dichotomy for Pulsars with Extreme Inclinations

In this work, we expand on a comment by Lyne et al. (2017), that intermittent pulsars tend to congregate near a stripe in the logarithmic period versus period-derivative diagram. Such a stripe represents a small range of polar cap electric potential. Taking into account also the fact (already apparent in their Figure 7, but not explicitly stated there) that high-fraction nulling pulsars also tend to reside within this and an additional stripe, we make the observation that the two stripes further match the “death lines” for double- and single-pole interpulses, associated with nearly orthogonal and aligned rotators, respectively. These extreme inclinations are known to suffer from pair production deficiencies, so we propose to explain intermittency and high-fraction nulling by reinvigorating some older quiescent (no pulsar wind or radio emission) “electrosphere” solutions. Specifically, as the polar potential drops below the two threshold bands (i.e., the two stripes), corresponding to the aligned and orthogonal rotators, their respective magnetospheres transition from being of the active pair-production-sustained-type into becoming the electrospheres, in which charges are only lifted from the star. The borderline cases sitting in the gap outside of the stable regime of either case manifest as high-fraction nullers. Hall evolution of the magnetic field inside orthogonally rotating neutron stars can furthermore drive secular regime changes, resulting in intermittent pulsars.

Dyonic Reissner–Nordstrom black holes and superradiant stability

Black holes immersed in magnetic fields are believed to be important systems in astrophysics. One interesting topic on these systems is their superradiant stability property. In the present paper, we analytically obtain the superradiantly stable regime for the asymptotically flat dyonic Reissner–Nordstrom black holes with charged massive scalar perturbation. The effective potential experienced by the scalar perturbation in the dyonic black hole background is obtained and analyzed. It is found that the dyonic black hole is superradiantly stable in the regime $$0<r_{-}/r_{+}<2/3$$ 0 < r - / r + < 2 / 3 , where $$r_\pm $$ r ± are the event horizons of the dyonic black hole. Compared with the purely electrically charged Reissner–Nordstrom black hole case, our result indicates that the additional coupling of the charged scalar perturbation with the magnetic filed makes the black hole and scalar perturbation system more superradiantly unstable, which provides further evidence on the instability induced by magnetic field in black hole superradiance process.

Micrometeorological Aspects of Spraying within a Surface Inversion.

Pesticide applications during surface inversions can lead to spray drift causing severe damage up to several kilometers off-target. Current regulations in Australia prohibit spray application of certain agricultural chemicals when hazardous surface inversions exist. This severely limits spray opportunities.Surface inversions can be classified as weakly or strongly stable. In the weakly stable case, moderate to strong turbulent mixing is not supportive of long-distance concentrated drift. In the very stable case, weak turbulent mixing can support the transport of high concentrations of fine material over long distances. A review of the literature and our analyses indicate that if the turbulence, as measured by the standard deviation of the vertical wind speed σw, is greater than about 0.2 m/s then turbulence-driven mixing and dispersion is moderate to strong and conversely if σw is less than about 0.2 m/s then turbulence-driven mixing and dispersion is weaker (an order of magnitude). The concept of maximum downward heat flux as a natural division between the regimes is applied within Monin-Obukhov Stability Theory and it is shown that the observed mean σw of 0.2 m/s aligns with the ridge line of maximum heat flux in stable conditions. The level of turbulence in the weakly stable regime is comparable to the turbulence typically observed in near-neutral conditions which are recommended under current guidelines as suitable for spraying and is therefore seen as an acceptable prerequisite to avoid non-dispersive spraying conditions.

Optomechanically Induced Transparency and Slow–Fast Light Effect in Hybrid Cavity Optomechanical Systems

We theoretically investigate the optomechanically induced transparency (OMIT) phenomenon and the fast and slow light effects of a four-mode optomechanical system with the Kerr medium. The optomechanical system is composed of an array of three single-mode cavities and a mechanical oscillator. The three cavities are a passive cavity, a no-loss-gain cavity and a gain optical cavity, respectively. A Kerr medium is inserted in the passive cavity. We study the influence of the Kerr medium on the stability of the optomechanical system, and find that the stable regime of the optomechanical system can be adjusted by changing the Kerr coefficient. We demonstrate that the phenomenon of optomechanically induced transparency will appear when the Kerr medium exists in the optomechanical system and find that the frequency position of the absorption peak on the left increases linearly with the Kerr coefficient. In addition, we also investigate the fast and slow light effects in this system. The results show that we can control the fast and slow light by adjusting the Kerr coefficient, tunneling strength, and driving field strength. This study has potential application prospects in the fields of quantum optical devices and quantum information processing.