Fast fluorescence dynamics in non-ratiometric calcium indicators

A fluorescence decay of high-affinity non-ratiometric Ca2+ indicator Oregon Green BAPTA-1 (OGB-1) is analyzed with unprecedented temporal resolution in the two-photon excitation regime. A triple exponential decay is shown to best fit the fluorescence dynamics of OGB-1. We provide a new model for accurate measurements of the free Ca2+ concentration and dissociation constants of non-ratiometric calcium indicators.Comment: 3 pages, 2 figures, figures revised, added chi-square goodness of fi

PROBLEMATIC ASPECTS OF FINANCIAL RISK ASSESSMENT METHODOLOGY IN STEVEDORING COMPANIES

The study is dedicated to identification of problematic aspects of financial risk assessment methodology on the example of stevedoring companies. In research established the list of issues for improvement the methodology of financial risk assessment both in theoretical and practical aspects. Formulated industry features of the stevedoring companies’ activity, relevant factors from the perspective of financial risk impact on results of activity, among which are distinguished: loss of net sales, exchange rate instability and decrease of financial stability. It was found that the loss of net income from the sale of state stevedoring companies of Ukraine occurred: due to the failure to fulfill the plan of cargo processing by reducing the number of the number of ship-measures and change of the nomenclature of cargo towards the less profitable and instability of the US dollar. Particular attention is paid to assessing the level of financial stability of state-owned stevedoring companies in Ukraine and identifies a downward trend in recent years. It is argued that the definition of factors that affect financial risks should be conducted using factor analysis, mathematical models that require comprehensive consideration of uncertainty factors and related to the peculiarities of stevedoring companies operation. The feasibility of drawing up a financial risk map and the options of management's response to their presence have been proved.The study is dedicated to identification of problematic aspects of financial risk assessment methodology on the example of stevedoring companies. In research established the list of issues for improvement the methodology of financial risk assessment both in theoretical and practical aspects. Formulated industry features of the stevedoring companies’ activity, relevant factors from the perspective of financial risk impact on results of activity, among which are distinguished: loss of net sales, exchange rate instability and decrease of financial stability. It was found that the loss of net income from the sale of state stevedoring companies of Ukraine occurred: due to the failure to fulfill the plan of cargo processing by reducing the number of the number of ship-measures and change of the nomenclature of cargo towards the less profitable and instability of the US dollar. Particular attention is paid to assessing the level of financial stability of state-owned stevedoring companies in Ukraine and identifies a downward trend in recent years. It is argued that the definition of factors that affect financial risks should be conducted using factor analysis, mathematical models that require comprehensive consideration of uncertainty factors and related to the peculiarities of stevedoring companies operation. The feasibility of drawing up a financial risk map and the options of management's response to their presence have been proved

Computer simulation of operation plant effective modes for water disinfection by electrical discharges in gas bubbles

Purpose. Determination by means of computer simulation of the most efficient modes of operation of the installation for water disinfection using discharges in gas bubbles, in which (modes) the amplitude of voltage pulses at the processing unit and on the layer of treated water is not less than the voltage amplitude immediately after the switching discharger. Methodology. To achieve this goal, we used computer simulation using Micro-Cap 10. We used two different electrical circuits that simulate the operation of the experimental setup in two different modes: in a mode with a restoring electrical strength of the discharge gap in the gas bubble between two adjacent voltage pulses on the discharge node and in the mode without restoring this dielectric strength. In computer simulation, we varied the following factors: the maximum simulation step, inductances, capacitances, active resistances, wave resistance of a long line, and the delay time for the operation of a spark gap simulating a discharge gap in a gas bubble. Results. Computer modeling has shown that in order to increase the voltage amplitude at the treatment unit and on the layer of treated water, it is necessary to reduce the load capacitance – the capacitance of the water layer in the treatment unit to 10 pF or less, to increase the active resistance of the water layer to 500 W or more. An important factor for increasing the voltage and electric field strength in the discharge unit and, consequently, for increasing the efficiency of treated water disinfection is the discharge delay time in gas bubbles. The most rational delay time for the operation of the arrester, which is the gap in the gas bubble inside the water, under the conditions considered by us is 4–5 ns. It is with this delay time that the amplitude of voltage pulses at the node of disinfecting water treatment and on the layer of treated water is maximum, all other things being equal. Furthermore, with such a delay time this amplitude of voltage pulses significantly exceeds the voltage amplitude directly after the main high-voltage discharger, switching energy from the high-voltage capacitive storage to the processing unit through a long line filled with water. Originality. Using computer simulation, we have shown the possibility of increasing the voltage at the discharge unit of the experimental setup by 35 % without increasing the voltage of the power source. This provides a higher efficiency of microbiological disinfection of water by nanosecond discharges in gas bubbles and lower specific energy consumption. Practical value. The obtained results of computer simulation confirm the prospect of industrial application of installations using nanosecond discharges for disinfection and purification of wastewater, swimming pools and post-treatment of tap water.Мета. Визначення за допомогою комп’ютерного моделювання найбільш ефективних режимів роботи установки для знезараження води за допомогою розрядів у газових бульках, при яких (режимах) амплітуда імпульсів напруги на вузлі обробки та на шарі води, що обробляється, не менше амплітуди напруги безпосередньо після комутуючого розрядника. Методика. Для досягнення поставленої мети ми використовували комп’ютерне моделювання за допомогою Micro-Cap 10. Ми використовували дві різні електричні схеми, що моделюють роботу експериментальної установки в двох різних режимах: в режимі з електричною міцністю, що відновлюється, розрядного проміжку в газовій бульці між двома сусідніми імпульсами напруги на розрядному вузлі та у режимі без відновлення цієї електричної міцності. При комп’ютерному моделюванні варіювалися такі фактори: максимальний крок при моделюванні, індуктивності, ємності, активні опори, хвильовий опір довгої лінії, час затримки спрацьовування розрядника, що моделює розрядний проміжок у газовому міхурі. Результати. Комп’ютерне моделювання показало, що для збільшення амплітуди напруги на вузлі обробки і на шарі води, що обробляється, слід зменшувати навантажувальну ємність – ємність шару води у вузлі обробки до 10 пФ і менше, збільшувати активний опір шару води до 500 Ом і більше. Важливим чинником збільшення напруги і напруженості електричного поля в розрядному вузлі і, отже, збільшення ефективності знезараження оброблюваної води є час затримки розряду в газових бульбашках. Найбільш раціональний час затримки спрацьовування розрядника, яким є зазор у газовій бульці всередині води, у розглянутих умовах становить 4-5 нс. Саме при такому часі затримки амплітуда імпульсів напруги на вузлі знезаражувальної обробки води і на шарі оброблюваної води є максимальною за інших рівних умов і істотно перевищує амплітуду напруги безпосередньо після основного високовольтного розрядника, що комутує енергію з високовольтного ємнісного нагромаджувача у вузол обробки. Наукова новизна. За допомогою комп’ютерного моделювання показана можливість підвищення напруги на розрядному вузлі експериментальної установки на 35 % без збільшення напруги джерела живлення, що забезпечує більш ефективне мікробіологічне знезараження води за допомогою наносекундних розрядів у газових бульбашках за малих питомих витрат енергії. Практична значущість. Отримані результати комп’ютерного моделювання підтверджують перспективу промислового застосування установок з використанням наносекундних розрядів для знезараження та очищення стічних вод, басейнів та доочищення водопровідної води

Photoproduction off the nucleon revisited: Evidence for a narrow N(1688) resonance?

Revised analysis of $\Sigma$ beam asymmetry for the $\eta$ photoproduction on the free proton reveals a structure at $W\sim 1.69$ GeV. Fit of the experimental data based on the E429 solution of the SAID partial wave analysis suggests a narrow ($\Gamma \leq 25$ MeV) resonance. Possible candidates are $P_{11}, P_{13}$, or $D_{13}$ resonances. The result is considered in conjunction with the recent evidence for a bump-like structure at $W\sim 1.67 - 1.68$ GeV in the quasi-free $\eta$ photoproduction on the neutron.Comment: Contribution to the Workshop on the Physics of the Excited Nucleons NSTAR2007, Bonn, Germany, Sept. 5 - 8 2007. To be published in Eur.Phys.J.

Tools for building production and woodworking made from the perforated steel wastes

ArticleThe rising of efficiency of the building and construction production is an actual task. One of the possible ways to ensure higher efficiency is using innovative tools and facilities of small-scale mechanization, which increase productivity and enchase working condition. Most observable influence of such strategy is on concrete works, plastering and earthworks. Another important tendency in production engineering, building and construction production is recycling of the technological wastes, which sufficiently reduce cost of the products and improve ecology. The goal of the present paper is to offer new possibility for recycling of the technological wastes, i.e. perforated steel tapes achieved after stamping of fine parts, by producing from mentioned perforated tapes the building tools and facilities of small-scale mechanization. In particular, the technological wastes of the JSC ‘Ditton’ (Daugavpils, Latvia) – perforated steel tapes – received after stamping of the elements of driving chains for different apparatus were used in this research. The prototypes of the scrapers for the finishing building work, as well as cutting edges and circular coronas for the woodworking were elaborated and offered in this work. The results of approbation of elaborated prototypes of the tools are offered. It was proven, that proposed innovative tools could be used effectively in building production and woodworking

Photogrammetry and ballistic analysis of a high-flying projectile in the STS-124 space shuttle launch

A method combining photogrammetry with ballistic analysis is demonstrated to identify flying debris in a rocket launch environment. Debris traveling near the STS-124 Space Shuttle was captured on cameras viewing the launch pad within the first few seconds after launch. One particular piece of debris caught the attention of investigators studying the release of flame trench fire bricks because its high trajectory could indicate a flight risk to the Space Shuttle. Digitized images from two pad perimeter high-speed 16-mm film cameras were processed using photogrammetry software based on a multi-parameter optimization technique. Reference points in the image were found from 3D CAD models of the launch pad and from surveyed points on the pad. The three-dimensional reference points were matched to the equivalent two-dimensional camera projections by optimizing the camera model parameters using a gradient search optimization technique. Using this method of solving the triangulation problem, the xyz position of the object's path relative to the reference point coordinate system was found for every set of synchronized images. This trajectory was then compared to a predicted trajectory while performing regression analysis on the ballistic coefficient and other parameters. This identified, with a high degree of confidence, the object's material density and thus its probable origin within the launch pad environment. Future extensions of this methodology may make it possible to diagnose the underlying causes of debris-releasing events in near-real time, thus improving flight safety.Comment: 26 pages, 11 figures, 3 table

Band structures for binding and holding of objects made from recycled metallic materials

ArticleThe aim of the present research is the investigation of the possibility and effectiveness of using the band structures made from recycled metallic materials for binding and holding of objects (in particular, tubular objects as pipelines or shells). The using of band elements and structures as such is a perspective way to increase the safety and bearing capacity of the pipelines and vessels. Nowadays during repair works the outer surfaces of the mentioned objects are braided by the steel tapes, i.e. the objects are strengthened by the binding. The mentioned steel bands are specially produced for binding purpose. From the other hand after stamping of smallsize details (like the elements of supply chains for different apparatus) the metallic waste in the shape of perforated metallic tapes are received and needs to be reused in compliance with the good practice in effective resource using and recycling. The band structures for binding and holding of tubular objects, produced from the perforated metallic tape by the longitudinal profiling, multilayer and spiral winding are presented. It is proposed to apply in industry the composite band structures made from perforated metallic materials and epoxy matrix for binding and holding of tubular objects as pipelines or shells, which allows simplifying and speeding up the repair works especially in the cases of the local damages