Aim. To study prevalence of arterial hypertension (AH), mean values of systolic and diastolic blood pressure (SBP, DBP), awareness of patients about their disease, medication consumption (MC) and efficacy of treatment in several regions of Russia.Material and methods. Representative selections were made in 9 regions of Russia: men (n=5563), women (n=9737) of 25–64 y.o., studied in 2012–2013 with the response 80%. Systematic stratified multilevel random selection was formed with localilty criteria (Kisch method). The Questionnaire on the presence of AH included: awareness of the patient about his disease, drug intake. BP measurement was performed on the right arm by automatic tonometer Omron in sitting position after 5 minutes resting. The mean value of two measurements was used. BP defined as SBP ≥140 mmHg, DBP ≥90 mmHg, or if the patient had taken antihypertensive therapy. Efficacy of treatment — the part of patients (in %) who reached target BP. Control group — part of patients (in %) with BP <140/90 mmHg. Statistic data calculation was done with computer-based statistic software — SAS with standardising by age stratification of Europe.Results. Mean SBP and DBP were 130,7±0,1 mmHg and 81,6±0,1 mmHg respectively. Prevalence of AH — 44%, higher in men (p<0,001). Prevalence of AH was higher in rural area citizens in men — 51,8% vs 47,5% (р<0,02) and in women — 42,9% vs 40,2% (р<0,05). Awareness was 67,5% in men, 78,9% in women. Medications were taken by 60,9% of women and 39,5% of men. Effectively treated were 53,5% of women and 41,4% of men. With the age the part of effectively treated decreases (p<0,0005). BP is under control only in 1/3 of women and 14,4% of men.Conclusion. The role of AH as one of the main modifiable risk factors of cardiovascular diseases is proved, however it is depressing that the percent of controlled AH is low. BP control is the main task of outpatient surveillance at every local outpatient department, where now less than a half of those affected are being observed.

The paper presents the results of systematic measurements of the thermal conductivity coefficient of nanofluids at room temperature. In total, more than fifty various nanofluids based on water, ethylene glycol, and engine oil containing particles of SiO2, Al2O3, TiO2, ZrO2, CuO, and diamond were studied. The nanoparticles volume concentration ranged from 0.25 to 8% and the particles size ranged from 10 to 150 nm. It is shown that the thermal conductivity of nanofluids is not described by the classical theories (Maxwell's and so forth). The nanofluid thermal conductivity coefficient is a complicated function not only of the particle concentration, but also the particles size, their material, and type of base fluid. Measured thermal conductivity coefficients almost always exceed the values calculated by the Maxwell's formula, though nanofluids with sufficiently small particles may have thermal conductivity coefficients even lower than those predicted by the Maxwell theory. However, in all cases, the nanofluid thermal conductivity coefficient enhances with increasing particle size. It is convincingly shown that there is no direct correlation between the thermal conductivity of the nanoparticle material and the thermal conductivity of nanofluid containing these particles. The base liquid also significantly influences the effective thermal conductivity of the nanofluid. It has been confirmed that the lower the thermal conductivity of the base fluid, the higher the relative thermal conductivity coefficient of the nanofluid.

The numerical investigation of the flow regimes in the T-shaped microchannels with different width-to-height aspect ratios of mixing channel was carried out. In the first case, the mixing channel width was varied from 200 m to 1000 m while its height was constant; in the second case, the mixing channel height was varied from 100 m to 2000 m, while its width was constant. The Reynolds number was varied from 5 to 700. The dependences of fluids mixing efficiency and the pressure drop on the Reynolds number at different width-to-height aspect ratios of mixing channel were numerically established. The correlations to determine the critical Reynolds number, as well as the friction factor at different widths and heights of the mixing channel, were proposed. The mixing efficiency, reduced to the pressure drop and the volume unit was analyzed for the first time. The optimal range of parameters in terms of the working efficiency of the micromixer was determined.