Effective slip over superhydrophobic surfaces in thin channels

Superhydrophobic surfaces reduce drag by combining hydrophobicity and roughness to trap gas bubbles in a micro- and nanoscopic texture. Recent work has focused on specific cases, such as striped grooves or arrays of pillars, with limited theoretical guidance. Here, we consider the experimentally relevant limit of thin channels and obtain rigorous bounds on the effective slip length for any two-component (e.g. low-slip and high-slip) texture with given area fractions. Among all anisotropic textures, parallel stripes attain the largest (or smallest) possible slip in a straight, thin channel for parallel (or perpendicular) orientation with respect to the mean flow. For isotropic (e.g. chessboard or random) textures, the Hashin-Strikman conditions further constrain the effective slip. These results provide a framework for the rational design of superhydrophobic surfaces.Comment: 4+ page

Formation en langues étrangères des spécialistes dans les universités techniques

Les langues étrangères sont très importantes aujourd'hui pour un spécialiste. Une bonne connaissance de plusieurs langues étrangères est utile pour trouver un emploi, surtout s'il est populaire dans telles langues que l'anglais, l'allemand ou le français. Cela est dû non seulement au fait que la plupart des entreprises collaborent avec des partenaires et investisseurs étrangers, mais aussi parce que la connaissance des langues étrangères élargit considérablement le monde des spécialistes et les aide à s'améliorer

Total cardiovascular risk among native population of Kyrgyzstan with diabetes mellitus type 2 and impaired glucose tolerance in high- and low-altitude regions

Objective: In  diabetes  mellitus (DM) type 2, there  is  a  very  high  risk  of developing cardiovascular  (CV) events.  We aimed to study the total CV risk of the indigenous people of  Kyrgyzstan with  impaired carbohydrate metabolism (DM type 2 and impaired glucose tolerance, IGT), depending on  the region of residence (low and high altitudes), and to  develop targeted preventive measures. Methods: Overall, 248 families (992 people) in the Naryn (high-altitude) (study group) and 260 families (1041 people) in the Chui region (low-altitude) (control group) were surveyed and  363 people with DM type 2 and IGT were identified, of which: 138 people in the study group and 225 people in the control group. Results: In patients with DM type 2 and IGT, moderate CV risk was found in the low-altitude and high-altitude in men and women aged 46–65 years, the  leading risk factor in men is BMI&qt;25 kg/m2; in women, hypertension (HT)  and hypercholesterolemia. A high risk of  CV  complications was detected only in the low-altitude in men aged 46–65 years, the leading risk factor is HT. High and very high risk of CV complications  are rarely found both in the low-altitude and in the high-altitude. Conclusion: During stratification of total CV risk, 363 people with carbohydrate metabolism disorders (DM type 2 and IGT) of  2033 native population living in 2  regions  of Kyrgyzstan revealed features of the total CV risk: BMI&qt;25kg/m2 for men of  high- altitude  and  low-altitude,  HT  and hypercholesterolemia  for  women of high-altitude, and for men, low-altitude only HT. Both in the high-altitude and in the low-altitude, low and moderate CV risk are predominantly expressed, and high and very high CV risk are rare

The Minimum-Uncertainty Squeezed States for for Atoms and Photons in a Cavity

We describe a six-parameter family of the minimum-uncertainty squeezed states for the harmonic oscillator in nonrelativistic quantum mechanics. They are derived by the action of corresponding maximal kinematical invariance group on the standard ground state solution. We show that the product of the variances attains the required minimum value 1/4 only at the instances that one variance is a minimum and the other is a maximum, when the squeezing of one of the variances occurs. The generalized coherent states are explicitly constructed and their Wigner function is studied. The overlap coefficients between the squeezed, or generalized harmonic, and the Fock states are explicitly evaluated in terms of hypergeometric functions. The corresponding photons statistics are discussed and some applications to quantum optics, cavity quantum electrodynamics, and superfocusing in channeling scattering are mentioned. Explicit solutions of the Heisenberg equations for radiation field operators with squeezing are found.Comment: 27 pages, no figures, 174 references J. Phys. B: At. Mol. Opt. Phys., Special Issue celebrating the 20th anniversary of quantum state engineering (R. Blatt, A. Lvovsky, and G. Milburn, Guest Editors), May 201

Lung memory T-cell response in mice following intranasal immunization with influenza vector expressing mycobacterial proteins

Improving specific prevention of tuberculosis continues to be a top priority in phthisiology. “Prime-boost” vaccination schemes aim to maintain adequate levels of specific immunity while forming long-term protection. They are based on sequential use of BCG vaccine and new vaccine candidates expressing protective mycobacterial proteins. The development of new tuberculosis prevention approaches requires an understanding of how the anti-tuberculosis immune response forms and which mechanisms provide TB protection. Since tuberculosis is an airborne infection, vaccine effectiveness largely depends on mucosal immunity based on the formation of long-lived, functionally-active memory T-lymphocytes in the respiratory tract. We have previously shown that the influenza vector expressing ESAT-6 and Ag85A mycobacterial proteins (Flu/ESAT-6_Ag85A) in vaccination scheme of intranasal boost immunization resulted in significant increase of BCG's protective effect according to key indicators aggregate data in experimental tuberculosis infection. The aim of this work was to study the effect of intranasal immunization with the Flu/ESAT-6_Ag85A influenza vector on the formation of antigen-specific central and effector memory T cells and the cytokine-producing activity of effector T cells (TEM) in BCG standard and “BCG prime — influenza vector boost” vaccination schemes in mice. Intranasal immunization with the influenza vector has been shown to increase the proportion of antigen-specific CD4+ central memory T cells (TCM) in the pool of activated lymphocytes of lung and spleen reaching significant differences from the BCG group in the percentage of spleen CD4+ TCM (p < 0.01). In contrast to BCG, vaccination with the studied vaccine candidate was accompanied by accumulation of highly differentiated CD8 effector cells in lung, the target organ during tuberculosis infection. Comparative evaluation of the cell-mediated, post-vaccine immune response after immunization with influenzavector-based vaccine candidate (intranasal/mucosal) or BCG vaccine (subcutaneous) showed advantages in the mucosal group: in formation of functionally active subpopulations of effector CD4 and CD8 T lymphocytes (CD44highCD62Llow) in lungs secreting IL-2 as well as polyfunctional cells capable of coproducing two cytokines (IFNγ/TNFα or IFNγ/IL-2) or three cytokines (IFNγ/TNFα/IL-2). Due to their more pronounced effector function, polyfunctional T-lymphocytes can be considered to be potential immunological markers of protective immunity in tuberculosis

Load carrying capacity of a heterogeneous surface bearing

It has been shown before that liquids can slip at a solid boundary, which prompted the idea that parallel-surfaces bearings can be achieved just by alternating slip and non-slip regions in the direction of fluid flow. The amount of slip at the wall depends on the surface tension at the liquid–solid interface, which in turn depends on the chemical state of the surface and its roughness. In the present study a heterogeneous surface was obtained by coating half of a circular glass disc with a coating repellant to glycerol. A rotating glass disc was placed at a known/calibrated distance and the gap was filled with glycerol. With the mobile surface moving from the direction of slip to non-slip region it can be theoretically shown that a pressure build up can be achieved. The pressure gradient in the two regions is constant, similar to that in a Rayleigh step bearing, with the maximum pressure at the separation line. The heterogeneous disc was placed on a holder supported by a load cell thus the force generated by this pressure increase can be measured accurately. Tests were carried out at different sliding speeds and gaps and the load carried was measured and subsequently compared with theoretical calculations. This allowed the slip coefficient to be evaluated

Bacterial contamination of food products with violations in the technological process as a factor in the occurrence of acute intestinal infections

The aim of the study – to conduct a hygienic assessment of the results of laboratory studies of finished products (chicken semi–finished products) of the Reftinskaya poultry farm (hereinafter referred to as Reftinskaya PF) conducted within the framework of control and supervisory measures, to assess the frequency of occurrence of OKI depending on the safety of the products used by Reftinskaya PF.Цель исследования – провести гигиеническую оценку результатов лабораторных исследований готовой продукции (куриных полуфабрикатов) птицефабрики «Рефтинская» (далее – ПФ «Рефтинская), проведенных в рамках контрольно-надзорных мероприятий, оценить частоту возникновения ОКИв зависимости отбезопасностиупотребляемой продукции ПФ «Рефтинская»

Lifshitz formula by spectral summation method

The Lifshitz formula is derived by making use of the spectral summation method which is a mathematically rigorous simultaneous application of both the mode-by-mode summation technique and scattering formalism. The contributions to the Casimir energy of electromagnetic excitations of different types (surface modes, waveguide modes, and photonic modes) are clearly retraced. A correct transition to imaginary frequencies is accomplished with allowance for all the peculiarities of the frequency equations and pertinent scattering data in the complex $\omega$ plane, including, in particular, the cuts connecting the branch points and complex roots of the frequency equations (quasi-normal modes). The principal novelty of our approach is a special choice of appropriate passes in the contour integrals, which are used for transition to imaginary frequencies. As a result, the long standing problem of cuts in the complex $\omega$ plane is solved completely. Inconsistencies of some previous derivations of the Lifshitz formula are traced briefly. For completeness of the presentation, the necessary mathematical facts are also stated, namely, solution of the Maxwell equations for configurations under consideration, scattering formalism for parallel plane interfaces, determination of the frequency equation roots, and others.Comment: The version published in Phys. Rev. A 86, 052503 (2012); criticism of some previous derivations of the Lifshitz formula is diminished (Introduction) and emphasizing the authors achievements (Conclusion) is moderate

Evaluating methane inventories by isotopic analysis in the London region

A thorough understanding of methane sources is necessary to accomplish methane reduction targets. Urban environments, where a large variety of methane sources coexist, are one of the most complex areas to investigate. Methane sources are characterised by specific δ13C-CH4 signatures, so high precision stable isotope analysis of atmospheric methane can be used to give a better understanding of urban sources and their partition in a source mix. Diurnal measurements of methane and carbon dioxide mole fraction, and isotopic values at King’s College London, enabled assessment of the isotopic signal of the source mix in central London. Surveys with a mobile measurement system in the London region were also carried out for detection of methane plumes at near ground level, in order to evaluate the spatial allocation of sources suggested by the inventories. The measured isotopic signal in central London (−45.7 ±0.5‰) was more than 2‰ higher than the isotopic value calculated using emission inventories and updated δ13C-CH4 signatures. Besides, during the mobile surveys, many gas leaks were identified that are not included in the inventories. This suggests that a revision of the source distribution given by the emission inventories is needed