Electro-osmosis on anisotropic super-hydrophobic surfaces

We give a general theoretical description of electro-osmotic flow at striped super-hydrophobic surfaces in a thin double layer limit, and derive a relation between the electro-osmotic mobility and hydrodynamic slip-length tensors. Our analysis demonstrates that electro-osmotic flow shows a very rich behavior controlled by slip length and charge at the gas sectors. In case of uncharged liquid-gas interface, the flow is the same or inhibited relative to flow in homogeneous channel with zero interfacial slip. By contrast, it can be amplified by several orders of magnitude provided slip regions are uniformly charged. When gas and solid regions are oppositely charged, we predict a flow reversal, which suggests a possibility of huge electro-osmotic slip even for electro-neutral surfaces. On the basis of these observations we suggest strategies for practical microfluidic mixing devices. These results provide a framework for the rational design of super-hydrophobic surfaces.Comment: 4 pages, 4 figures; submitted to PRL Revised version: several references added, typos corrected. Supplementary file was restructured, the second part of the original EPAPS was removed and is supposed to be published as a separate pape

Studying the Effectiveness of Teacher Training in Organization of Open Education

The modern concept of open education modifies the traditional learning format through advanced information and communications technology. This fact imposes special requirements for all participants in the learning process and makes it necessary to reconsider the tasks and functions of students and teachers. This is relevant, therefore, to find a way of making a gradual transition to the model of open education. Based on an experiment with introductory training, the authors perform an empirical assessment of teachers’ preparedness to organize open education and use open educational resources (OER). The effectiveness of the introductory training of teachers was checked by means of interviewing and testing respondents. The research results showed that there were significant changes in the training criteria: according to the motivational and value-based criterion, virtually all teachers displayed a positive shift in their attitude to organization of open education; in terms of the cognitive criterion, the teachers acquired thorough knowledge of open education tools; according to the operational criterion, the teachers acquired the necessary skills in developing and introducing OER. In the process of observation, we recorded a rise in the number of teachers with a sufficient (by 60.5% compared with the verification stage) and high (by 16.6%) level of preparedness. The introductory training, therefore, is a principal component in the stable system of open education

β-Keto phosphonic and phosphinic esters - Communication 6. Products of the reaction of chloro- and bromo-acetone with diethyl ethylphosphonite and with sodium ethyl ethylphosphonite

1. The action of diethyl ethylphosphonite on chloroacetone results in the formation of ethyl isopropenyl ethylphosphonate. In the case of bromoacetone, as well as ethyl isopropenyl ethylphosphonate, ethyl acetonylethylphosphinate is formed. 2. The reaction of chloroacetone with sodium ethyl ethylphosphonite gives ethyl (1,2-epoxy-1-methylethyl)ethylphosphinate. 3. A study was made of the Raman spectra and ultraviolet absorption spectra of previously undescribed compounds. © 1961 Consultants Bureau

Esters of β -ketophosphonic acids. VII. The products of the reaction of α-chlorocyclohexanone with the diethyl ester of ethylphosphonous acid and the sodium salt of the monoethyl ester of ethylphosphonous acid

The action of diethyl ethylphosphonite on α-chlorocyclohexanone gives cyclohexen-1-yl-1 -ethyl ethylphosphonate, Cyclohenen-1-yl-1-ethyl ethylphosphonate is also obtained by the action of sodium monoethyl ethylphosphonite on a-chlorocyclohexanone. © 1961 Consultants Bureau

Aspectos metodológicos de la evaluación de la eficiencia de la política social regional en la superación de la orfandad social

Among the methodological issues of studying the problem of social orphanhood, an important place is occupied by the search for effective markers for assessing dynamics on the one hand, and the effectiveness of social policy in overcoming social orphanhood on the other. That attempt to systematically evaluate the scale and severity of the phenomenon, as well as the key factors that determine its dynamics. However, these approaches do not allow us to identify the connection between social work and the dynamics of improving the situation with social orphanhood in the region. The presented study proposes a new model for assessing the dynamics of social orphanhood. Its difference from other methodological approaches is that the main emphasis is on assessing the orientation of the complex of shifts in the processes of identifying, placement of orphans and canceling decisions on their transfer to families. This model allows us to assess the role of social policy in overcoming social orphanhood. In this model, we developed authoring methods for ranking the regions of Russia by the dynamics of indicators integrated into the "auspiciousness" index of changes in the social orphanhood. Also, the author presents a model that assesses the situation in the region from the point of view of the "social support efficiency index" to overcome the social orphanhood. The models used to assess the dynamics of social orphanhood have been tested as a tool for identifying key markers of the efficiency of social policy.Entre las cuestiones metodológicas de estudiar el problema de la orfandad social, un lugar importante está ocupado por la búsqueda de marcadores efectivos para evaluar la dinámica, por un lado, y la efectividad de la política social para superar la orfandad social, por el otro. Ese intento de evaluar sistemáticamente la escala y la gravedad del fenómeno, así como los factores clave que determinan su dinámica. Sin embargo, estos enfoques no nos permiten identificar la conexión entre el trabajo social y la dinámica de mejorar la situación con la orfandad social en la región. El estudio presentado propone un nuevo modelo para evaluar la dinámica de la orfandad social. Su diferencia con otros enfoques metodológicos es que el énfasis principal está en evaluar la orientación del complejo de cambios en los procesos de identificación, colocación de huérfanos y cancelación de decisiones sobre su transferencia a las familias. Este modelo nos permite evaluar el papel de la política social en la superación de la orfandad social. En este modelo, desarrollamos métodos de autor para clasificar las regiones de Rusia por la dinámica de los indicadores integrados en el índice de "auspiciosidad" de los cambios en la orfandad social. Además, el autor presenta un modelo que evalúa la situación en la región desde el punto de vista del "índice de eficiencia del apoyo social" para superar la orfandad social. Los modelos utilizados para evaluar la dinámica de la orfandad social se han probado como una herramienta para identificar marcadores clave de la eficiencia de la política social

Connection of Social Policy Implementation with the Dynamics of Social Orphanhood in Russian Regions

The problem of social orphanhood is one of the most important fmong the social problems of modern Russia, it is acute for a society. In the study of the problems of social orphanage, we used the author’s methods of ranking the regions of Russia according to the dynamics of indicators, an integrated index of “favorable” changes, as well as rating data and indicators of the development of regions of Russia implemented by subjects of social policy and the system of protecting children's rights. Based on the results of the study, the main problems in the social protection of families and citizens in difficult situations are identified. The problems lie in the areas of financial security of social programs, legislative regulation, information support. The results of the study can be used in the activities of social support services. The preventive of social orphanage should be measures of an active social policy

Nonlinear acoustic waves in channels with variable cross sections

The point symmetry group is studied for the generalized Webster-type equation describing non-linear acoustic waves in lossy channels with variable cross sections. It is shown that, for certain types of cross section profiles, the admitted symmetry group is extended and the invariant solutions corresponding to these profiles are obtained. Approximate analytic solutions to the generalized Webster equation are derived for channels with smoothly varying cross sections and arbitrary initial conditions.Comment: Revtex4, 10 pages, 2 figure. This is an enlarged contribution to Acoustical Physics, 2012, v.58, No.3, p.269-276 with modest stylistic corrections introduced mainly in the Introduction and References. Several typos were also correcte

Optical echo in photonic crystals

The dynamics of photonic wavepacket in the effective oscillator potential is studied. The oscillator potential is constructed on a base of one dimensional photonic crystal with a period of unit cell adiabatically varied in space. The structure has a locally equidistant discrete spectrum. This leads to an echo effect, i.e. the periodical reconstruction of the packet shape. The effect can be observed in a nonlinear response of the system. Numerical estimations for porous-silicon based structures are presented for femtosecond Ti:Sapphire laser pump.Comment: 4 page

Quaternionic factorization of the Schroedinger operator and its applications to some first order systems of mathematical physics

We consider the following first order systems of mathematical physics. 1.The Dirac equation with scalar potential. 2.The Dirac equation with electric potential. 3.The Dirac equation with pseudoscalar potential. 4.The system describing non-linear force free magnetic fields or Beltrami fields with nonconstant proportionality factor. 5.The Maxwell equations for slowly changing media. 6.The static Maxwell system. We show that all this variety of first order systems reduces to a single quaternionic equation the analysis of which in its turn reduces to the solution of a Schroedinger equation with biquaternionic potential. In some important situations the biquaternionic potential can be diagonalized and converted into scalar potentials