Planar Airy beam light-sheet for two-photon microscopy

We demonstrate the first planar Airy light-sheet microscope. Fluorescence light-sheet microscopy has become the method of choice to study large biological samples with cellular or sub-cellular resolution. The propagation-invariant Airy beam enables a ten-fold increase in field-of-view with single-photon excitation; however, the characteristic asymmetry of the light-sheet limits its potential for multi-photon excitation. Here we show how a planar light-sheet can be formed from the curved propagation-invariant Airy beam. The resulting symmetric light sheet excites two-photon fluorescence uniformly across an extended field-of-view without the need for deconvolution. We demonstrate the method for rapid two-photon imaging of large volumes of neuronal tissue.Comment: 7 pages, 4 figure

Search for neutral charmless B decays at LEP

A search for rare charmless decays of \Bd and \Bs mesons has been performed in the exclusive channels \Bd_{(\mathrm s)}\ra\eta\eta, \Bd_{(\mathrm s)}\ra\eta\pio and \Bd_{(\mathrm s)}\ra\pio\pio. The data sample consisted of three million hadronic \Zo decays collected by the L3 experiment at LEP from 1991 through 1994. No candidate event has been observed and the following upper limits at 90\% confidence level on the branching ratios have been set \begin{displaymath} \mathrm{Br}(\Bd\ra\eta\eta)<4.1\times 10^{-4},\,\, \mathrm{Br}(\Bs\ra\eta\eta)<1.5\times 10^{-3},\,\, \end{displaymath} \begin{displaymath} \mathrm{Br}(\Bd\ra\eta\pio)<2.5\times 10^{-4},\,\, \mathrm{Br}(\Bs\ra\eta\pio)<1.0\times 10^{-3},\,\, \end{displaymath} \begin{displaymath} \mathrm{Br}(\Bd\ra\pio\pio)<6.0\times 10^{-5},\,\, \mathrm{Br}(\Bs\ra\pio\pio)<2.1\times 10^{-4}. \end{displaymath} These are the first experimental limits on \Bd\ra\eta\eta and on the \Bs neutral charmless modes

Ionic liquids at electrified interfaces

Until recently, “room-temperature” (<100–150 °C) liquid-state electrochemistry was mostly electrochemistry of diluted electrolytes(1)–(4) where dissolved salt ions were surrounded by a considerable amount of solvent molecules. Highly concentrated liquid electrolytes were mostly considered in the narrow (albeit important) niche of high-temperature electrochemistry of molten inorganic salts(5-9) and in the even narrower niche of “first-generation” room temperature ionic liquids, RTILs (such as chloro-aluminates and alkylammonium nitrates).(10-14) The situation has changed dramatically in the 2000s after the discovery of new moisture- and temperature-stable RTILs.(15, 16) These days, the “later generation” RTILs attracted wide attention within the electrochemical community.(17-31) Indeed, RTILs, as a class of compounds, possess a unique combination of properties (high charge density, electrochemical stability, low/negligible volatility, tunable polarity, etc.) that make them very attractive substances from fundamental and application points of view.(32-38) Most importantly, they can mix with each other in “cocktails” of one’s choice to acquire the desired properties (e.g., wider temperature range of the liquid phase(39, 40)) and can serve as almost “universal” solvents.(37, 41, 42) It is worth noting here one of the advantages of RTILs as compared to their high-temperature molten salt (HTMS)(43) “sister-systems”.(44) In RTILs the dissolved molecules are not imbedded in a harsh high temperature environment which could be destructive for many classes of fragile (organic) molecules

Asymmetric Bipolar Membrane for High Current Density Electrodialysis Operation with Exceptional Stability

Bipolar membranes (BPMs) enable isolated acidic/alkaline regions in electrochemical devices, facilitating optimized environments for electrochemical separations and catalysis. For economic viability, BPMs must attain stable, high current density operation with low overpotentials in a freestanding configuration. We report an asymmetric, graphene oxide (GrOx)-catalyzed BPM capable of freestanding electrodialysis operation at 1 A cm-2 with overpotentials &lt;250 mV. Use of a thin anion-exchange layer improves water transport while maintaining near unity Faradaic efficiency for acid and base generation. Voltage stability exceeding 1100 h with an average drift of 70 μV/h at 80 mA cm-2 and 100 h with an average drift of −300 μV/h at 500 mA cm-2 and implementation in an electrodialysis stack demonstrate real-world applicability. Continuum modeling reveals that water dissociation in GrOx BPMs is both catalyzed and electric-field enhanced, where low pKa moieties on GrOx enhance local electric fields and high pKa moieties serve as active sites for surface-catalyzed water dissociation. These results establish commercially viable BPM electrodialysis and provide fundamental insight to advance design of next-generation devices

An experimental study of microwave stability near transition in the PSR

We have undertaken a study of microwave stability in the PSR storage ring under a variety of beam conditions near transition, including variable intensity and machine impedance, which can be independently controlled in the PSR. Results indicate that the general features of a linear stability model are valid, namely that the instability threshold becomes very small sufficiently close to transition. In addition, many nonlinear features are apparent and the results suggest an extended operating regime is possible with saturated, but otherwise benign, longitudinal fluctuations. Details of the linear model experimental results and corresponding simulations will be presented

Trends of credit service market development in Ukraine

Актуальність обраної теми підтверджується тим, що в Україні сформована банкоцентрична модель функціонування національного господарства, існує об’єктивна необхідність пошуку нових напрямків забезпечення стійкості банківської системи та зниження ймовірності прояву системних ризиків на основі диверсифікації напрямів діяльності банківських установ. Розширення спектра банківських послуг, що надаються клієнтам, дозволяє перерозподілити фінансові ризики, знижуючи рівень їх негативного впливу на ефективність роботи банку, сформувати нові канали надходження доходів. У результаті проведеного аналізу тенденцій розвитку банківської системи України виявлено, що з кожним роком кількість комерційних банків, які мають банківську ліцензію постійно зменшується, що в основному було спричинено важкою фінансово-економічною ситуацією в державі, кризовими явищами, веденням тимчасової адміністрації в банках та їх ліквідацією. Враховуючи високу ризиковість банківської діяльності, багато власників комерційних банків, особливо невеликих, можуть у майбутньому самоліквідуватись. У такому процесі актуалізуються питання підвищення обсягів надання кредитних послуг в Україні та зростання питомої ваги комісійних надходжень у загальній структурі доходів банківських установ. У статті проаналізовано сучасний стан розвитку ринку кредитних послуг в Україні, визначено особливості його функціонування. Оцінювання сучасного стану ринку кредитних послуг було проведено за допомогою аналізу класичних показників діяльності банківських установ в Україні, що дозволило визначити її базові особливості функціонування. Також були виявлені й труднощі проведення ґрунтовних досліджень їх надання клієнтам. Запропоновано методи впливу на ефективність процесу диверсифікації кредитних банківських послуг (визначення зовнішніх й внутрішніх умов диверсифікації кредитних банківських послуг і їх проектування на продуктову політику банку; типізація клієнтів та визначення перспективних цільових ринкових сегментів; визначення технологічних аспектів реалізації диверсифікації кредитних послуг комерційного банку; побудова прогнозних моделей продажів трансформованих продуктів та послуг комерційних банків; оцінка ефективності витрат на диверсифікацію кредитних банківських послуг).The importance of the chosen issue is confirmed by the fact that a bank-centered model of national economy functioning is formed in Ukraine, there is an objective need to find new directions for ensuring the stability of the banking system and reduce the probability of systemic risks manifestation on the basis of diversification of the banking institutions activity. Expansion of the banking services range provided to the customers makes it possible to redistribute financial risks, reducing the level of their negative impact on the bank operating efficiency, to form new revenue streams. Analysis of the trends of banking system development in Ukraine shows that every year the number of commercial banks having banking license is steadily decreasing, mainly as the result of difficult financial and economic situation in the country, crisis phenomena, temporary bank administration introduction and its dissolution. Taking into account high riskiness of banking activities, many commercial bank owners, especially small ones, can self-dissolve in the future. In such process, the problems of credit services volume increase in Ukraine and the growth of commission share in general income structure of banking institutions become actual. The current state of credit services market development in Ukraine is analyzed, the peculiarities of its functioning are identified in this paper. The evalution of the current state of credit services market is carried out due to the analysis of classical indicators of banking institutions activities in Ukraine making it possible to determine its basic functioning features. However, the difficulties of carrying out the profound research of their provision to the customers are also identified. Based on this, the methods of influence on the efficiency of credit banking services diversification process (definition of external and internal conditions of credit banking services diversification and their design on the bank product policy; customers typification and determination of promising target market segments; determination of technological aspects for implementation the commercial bank credit services diversification; construction of forecasting models for sales of commercial banks transformed products and services; estimation of cost effectiveness for credit banking services diversification) are proposed