Rheological peculiarities of surfactants additives used to foaming

У разі використання поверхнево-активних речовин для отримання розчинів, застосовуваних у системах автоматичного пожежогасіння, розв'язання рівнянь руху рідин при розрахунку характеристик потоків нерозривно пов'язане з урахуванням реологічних властивостей добавок, що використовуються в якості піноутворювачів. У зв'язку з цим, актуальними є питання вирішення завдань ефективного використання реологічних особливостей розчинів зазначеного типу, а також факторів, що впливають на них. Робота присвячена зазначеним питанням, наведені результати проведених віскозиметричних досліджень полімерних добавок певної концентрації, застосовуваних у практиці пожежогасіння. У результаті досліджень отримані реологічні криві, зроблена їх обробка, яка дала можливість знайти відповідні їм реологічні закони. Дані наведених реологічних досліджень використовувалися при визначенні втрат енергії і при розрахунках пожежних стволів з різною формою поперечного перерізу.The usage of surface active substances for solute receiving, which are a rather inevitable part of automatic fire-extinguishing system and the solution of equations concerning the motion of liquids while calculating flow’s characteristics are inseparably connected with rheological additives accounting. Such additives are used as foaming agents. In connection with this fact, the questions of solving the tasks concerning the effectiveness of rheological peculiar properties of solute of definite type solution and all factors influenced on it are still of current interest. The research is devoted to the mentioned questions. Also the results of viscometric researches of polymeric additives of certain concentration, which are used in firefighting practice are highlighted in it. As the result of the work the rheological graphs were received. Their processing gave an opportunity to find corresponding rheological laws. The data of rheological researches presented was used in energy loss finding and also in fire barrel with various cross-sectional shapes calculations.В случае использования поверхностно-активных веществ для получения растворов, применяемых в системах автоматического пожаротушения, решение уравнений движения жидкостей при расчете характеристик потоков неразрывно связано с учетом реологических свойств добавок, используемых в качестве пенообразователей. В связи с этим, актуальными есть вопросы решения задач эффективного использования реологических особенностей растворов указанного типа, а также факторов, влияющих на них. Работа посвящена указанным вопросам, приведены результаты проведенных вискозиметрических исследований полимерных добавок определенной концентрации, применяемых в практике пожаротушения. В результате исследований получены реологические кривые, сделана их обработка, которая дала возможность найти соответствующие им реологические законы. Данные приведенных реологических исследований использовались при определении потерь энергии и при расчетах пожарных стволов с различной формой поперечного сечения

Investigation of influence of electromagnetic field on electrochemical behaviour of heavy metal ions in the presence of butanol

By the method of inversion voltamperometry the action of high-frequency electromagnetic field of radio-frequiency bandwidth on current of anode peak Zn(II), Cd(II) and Pb(II) in the presence of butanol, molecules of which are adsorbed on the electron surface decreasing its free surface has been studied. As a result of the field influence on electrode-electrolyte system removing of electrode processes inhibition is shown to take place, it is conditioned by desorbtion of adsorbate molecules from electron surface. Desorbing action of high-frequency current is proved by measuring degree of electrode filling with butanol molecules and Frumkin's adsorbtion equation parameters

Heteronuclear ionizing collisions between laser-cooled metastable helium atoms

We have investigated cold ionizing heteronuclear collisions in dilute mixtures of metastable (2 3S1) 3He and 4He atoms, extending our previous work on the analogous homonuclear collisions [R. J. W. Stas et al., PRA 73, 032713 (2006)]. A simple theoretical model of such collisions enables us to calculate the heteronuclear ionization rate coefficient, for our quasi-unpolarized gas, in the absence of resonant light (T = 1.2 mK): K34(th) = 2.4*10^-10 cm^3/s. This calculation is supported by a measurement of K34 using magneto-optically trapped mixtures containing about 1*10^8 atoms of each species, K34(exp) = 2.5(8)*10^-10 cm^3/s. Theory and experiment show good agreement.Comment: 8 pages, 6 figure

The anticonvulsant retigabine suppresses neuronal Kv2-mediated currents

Enhancement of neuronal M-currents, generated through K(V)7.2-K(V)7.5 channels, has gained much interest for its potential in developing treatments for hyperexcitability-related disorders such as epilepsy. Retigabine, a K(V)7 channel opener, has proven to be an effective anticonvulsant and has recently also gained attention due to its neuroprotective properties. In the present study, we found that the auxiliary KCNE2 subunit reduced the K(V)7.2-K(V)7.3 retigabine sensitivity approximately 5-fold. In addition, using both mammalian expression systems and cultured hippocampal neurons we determined that low μM retigabine concentrations had ‘off-target’ effects on K(V)2.1 channels which have recently been implicated in apoptosis. Clinical retigabine concentrations (0.3–3 μM) inhibited K(V)2.1 channel function upon prolonged exposure. The suppression of the K(V)2.1 conductance was only partially reversible. Our results identified K(V)2.1 as a new molecular target for retigabine, thus giving a potential explanation for retigabine’s neuroprotective properties

Massive Black Hole Binary Inspirals: Results from the LISA Parameter Estimation Taskforce

The LISA Parameter Estimation (LISAPE) Taskforce was formed in September 2007 to provide the LISA Project with vetted codes, source distribution models, and results related to parameter estimation. The Taskforce's goal is to be able to quickly calculate the impact of any mission design changes on LISA's science capabilities, based on reasonable estimates of the distribution of astrophysical sources in the universe. This paper describes our Taskforce's work on massive black-hole binaries (MBHBs). Given present uncertainties in the formation history of MBHBs, we adopt four different population models, based on (i) whether the initial black-hole seeds are small or large, and (ii) whether accretion is efficient or inefficient at spinning up the holes. We compare four largely independent codes for calculating LISA's parameter-estimation capabilities. All codes are based on the Fisher-matrix approximation, but in the past they used somewhat different signal models, source parametrizations and noise curves. We show that once these differences are removed, the four codes give results in extremely close agreement with each other. Using a code that includes both spin precession and higher harmonics in the gravitational-wave signal, we carry out Monte Carlo simulations and determine the number of events that can be detected and accurately localized in our four population models.Comment: 14 pages, 2 figures, 5 tables, minor changes to match version to be published in the proceedings of the 7th LISA Symposium. For more information see the Taskforce's wiki at http://www.tapir.caltech.edu/dokuwiki/lisape:hom

Vitamin D supplementation in cutaneous malignant melanoma outcome (ViDMe): a randomized controlled trial.

L

Single particle tracking in systems showing anomalous diffusion: the role of weak ergodicity breaking

Anomalous diffusion has been widely observed by single particle tracking microscopy in complex systems such as biological cells. The resulting time series are usually evaluated in terms of time averages. Often anomalous diffusion is connected with non-ergodic behaviour. In such cases the time averages remain random variables and hence irreproducible. Here we present a detailed analysis of the time averaged mean squared displacement for systems governed by anomalous diffusion, considering both unconfined and restricted (corralled) motion. We discuss the behaviour of the time averaged mean squared displacement for two prominent stochastic processes, namely, continuous time random walks and fractional Brownian motion. We also study the distribution of the time averaged mean squared displacement around its ensemble mean, and show that this distribution preserves typical process characteristic even for short time series. Recently, velocity correlation functions were suggested to distinguish between these processes. We here present analytucal expressions for the velocity correlation functions. Knowledge of the results presented here are expected to be relevant for the correct interpretation of single particle trajectory data in complex systems.Comment: 15 pages, 15 figures; References adde