Risk Assessment at the Beginning and the End of Strouma River in Bulgaria Using Integral Indices

The present work considers Strouma River on the Bulgarian territory using the integral method for evaluation of climatic and anthropogenic impacts on the average annual water volume and maximum and minimum water flow. The level of this impact and risk assessment is determined by the index Mmax, i for the deviation of the maximum water flow from the maximum flow norm Qmax, 0 and the index Mmin, i for the deviation of the minimum water flow from the minimum flow norm Qmin, 0. Using the dynamics of the integral indices Mmax, i, Mmin, i and information on extreme events from the past, a preliminary risk assessment of future extreme events such as floods and draughts could be made. This is done for the first time in risk assessment of extreme events and has been checked at Pernik (in the beginning) and Marino pole (at the border in Greece) for the period 1948 - 2006

On a Fluid Outflow from a Bottle Turned Upside-Down

An incompressible viscous as well as nonviscous fluid outflow from an axially symmetric bottle turned upside-down is considered. This problem relates the gravity acceleration and air bubbles inflow into the bottle and in the mathematical sense presents a very complicated task. The simplified setting of problem based on a one-dimensional approximation of the fluid flow is proposed and results of numerical experiments are discussed

Spectral Properties of an Operator Associated with Hartree Type Equations with External Coulomb Potential

The work treats the nonexistence of zero resonance for the linearization of the Hartree type equation with external Coulomb potential around the solitary type solutions

A New Model for Predicting the Drag and Lift Forces of Turbulent Newtonian Flow on Arbitrarily Shaped Shells on the Seafloor

Currently, all forecasts of currents, waves, and seafloor evolution are limited by a lack of fundamental knowledge and the parameterization of small-scale processes at the seafloor-ocean interface. Commonly used Euler-Lagrange models for sediment transport require parameterizations of the drag and lift forces acting on the particles. However, current parameterizations for these forces only work for spherical particles. In this dissertation we propose a new method for predicting the drag and lift forces on arbitrarily shaped objects at arbitrary orientations with respect to the direction of flow that will ultimately provide models for predicting the sediment sorting processes that lead to the variability of shell fragments on inner shelf seafloors. We wish to develop the drag force parameterization specifically for a limpet shell through the linear regression of force estimated from high-fidelity Reynolds-averaged Navier-Stokes (RANS) simulations in OpenFOAM

Open-path ozone detection by quantum-cascade laser

Open-path ozone measurements performed by mid-IR differential absorption spectroscopy are reported. Ozone spectrum was taken by fast repetitive sweeping of a quantum-cascade laser wavelength over a spectral feature from the ν3 absorption band of ozone, centered at 1031.2cm-1. Short (100ns) sweeping times were essential to prevent line-distortions caused by atmospheric turbulence. For fast wavelength sweeping, a technique that employed the thermal chirp during 140ns excitation pulses was used. The lowest detection limit of 0.3ppm.m was estimated from the minimum detectable differential absorption. We present the results from cell and open-path measurements over 440 and 5800m, together with experimental data regarding the tuning range, the tuning rate and the tuning linearity of the QCL while operated with 140ns excitation pulse

Solid Liquid Extraction of Phenolic and Flavonoid Compounds from Cotinus coggygria and Concentration by Nanofiltration

Extraction kinetics of polyphenols and flavonoids from plant material and their separation and concentration by nanofiltration were investigated. The kinetics experiments were carried out with Cotinus coggygria. The influence of the extraction solvent on the extraction rate was defined. Four different extraction solvents or mixtures were applied – methanol, azeotropic ethanol, 50/50 ethanol/water mixture, and pure water. The optimum extraction rate of flavonoids and polyphenols was achieved by using 50 % ethanol as a solvent for extraction. This solvent mixture was used for generating extracts for the nanofiltration experiments. Organic solvent nanofiltration membranes from DuraMemTM series with different pore sizes (200, 300 500 and 900 Da) were tested in dead-end and cross-flow filtration systems. Flux and rejection data were obtained for every membrane type. Very good separation and respectively concentration of the extracted useful compounds was achieved (rejection for polyphenols and flavonoids is 91 and 93 %, respectively). During a feed/extract concentration experiment, the constant polyphenols and flavonoids rejection was measured. The results suggest that the nanofiltration technology could be combined successfully with solid-liquid extraction for natural sourced valuable compounds enrichment

Sexually Transmitted Infections Management Legal Regulation in Bulgaria: Present Situation and Challenges

Introduction: Sexually transmitted infections (STIs) continue to be a significant public health problem with numerous health social, ethical and economic dimensions. The goal of this study is to present and discuss the Bulgarian legal framework dimensions related to the management of the spectrum of STIs, and associated public health challenges. An analysis of Bulgarian legislation normative documents connected with the presented problematic was applied. Results: For the effective STIs-spectrum management, the presented normative acts envisage a number of rules and requirements for conducting preventive, diagnostic and treatment activities. These rules are not sufficient and cannot cover all cases in the practical work of medical professionals most of them serve as general guides. The main problem that is emerging is the lack of financial resources and sources of funding. Conclusion: Despite the large legal framework, most documents are only a framework, without specifics in the organization and lack of funding for regulated activities

Lidar measurement of atmospheric aerosol extinction profiles: a comparison between two techniques-Klett inversion and pure rotational Raman scattering methods

Two lidar methods of determining an atmospheric extinction coefficient profile are compared. The methods are the Klett inversion method for elastic lidar return and the log-derivative method for rotational Raman backscattered signal processing. The comparison includes numerical modeling and processing of lidar measurements when both the elastic and the rotational Raman backscattered signals are measured simultaneously. The suggested idea is that such a comparison can be used as a criterion for the reliability of the results of lidar measurements, similar to the comparison between the results of lidar and contact measurements

Simultaneous measurement of atmospheric temperature, humidity, and aerosol extinction and backscatter coefficients by a combined vibrational-pure-rotational Raman lidar

Implementation of the pure-rotational Raman (PRR) lidar method for simultaneous measurement of atmospheric temperature, humidity, and aerosol extinction and backscatter coefficients is reported. The isolation of two wavelength domains of the PRR spectrum and the suppression of the elastically scattered light is carried out by a double-grating polychromator. Experiments involving elastic backscatter from dense clouds and a solid target confirm the high level of suppression of the elastic light in the corresponding acquisition channels of the two selected PRR domains. Calibration of the temperature channel was done both by comparison with an experimentally verified atmospheric temperature model profile and by inter-comparison with radiosondes. Night-time temperature profiles with high vertical resolution were obtained up to the lower stratosphere. The PRR temperature profile combined with the water vapor mixing ratio obtained from the ro-vibrational Raman channel is used to estimate the relative humidit