Curing of epoxy resin DER-331by Hexakis (4-acetamidophenoxy) cyclotriphosphazene and properties of the prepared composition

The method of optical wedge revealed that the optimum temperature for compatibility of hexakis(4-acetamidophenoxy)cyclotriphosphazene (ACP) and DER-331 epoxy resin is in the range of 220–260◦C. The interdiffusion time of components at these temperatures is about 30 min. The TGA and differential scanning calorimetry (DSC) methods revealed the curing temperature of 280◦C for thiscomposition. IRspectroscopyconfirmedthatthereactionbetweentheresinandACPiscompleted within 10 mi

Laser Irradiation as a Tool to Control the Resonance Energy Transfer in Bacteriorhodopsin–Quantum Dot Bio-Nano Hybrid Material

 Bacteriorhodopsin (BR) is a natural photosensitive protein which can be considered promising in photovoltaics and optoelectronics because of its ability to produce a pronounced electrochemical response and controllably change its absorption spectrum under light excitation. However, its applicability is limited by its narrow absorption spectrum and low values of the absorption cross sections. Semiconductor quantum dots (QDs), which have high one- and two-photon absorption cross-sections in a UVand NIR spectral regions, respectively, can significantly improve the light sensitivity of BR by means of Förster resonance energy transfer (FRET) from QD to BR. In this work, we demonstrate the possibility to control the efficiency of FRET from QD to BR within electrostatically bound complexes of QD and purple membranes (PM) containing BR. We show that laser irradiation of QDs at different wavelengths leads to distinct changes (rise or decrease) of QD luminescence quantum yield (QY) without changing of QD structure. Such photo-induced changes in the QY of QD lead to a corresponding change in the efficiency of FRET. We have estimated efficiencies of FRET from QD to BR in the PM complexes composed of irradiated and non-irradiated QDs and found the increase in FRET efficiency with irradiated QDs

Influence of the photon - neutrino processes on magnetar cooling

The photon-neutrino processes $\gamma e^{\pm} \to e^{\pm} \nu \bar \nu$, $\gamma \to \nu \bar \nu$ and $\gamma \gamma \to \nu \bar \nu$ are investigated in the presence of a strongly magnetized and dense electron-positron plasma. The amplitudes of the reactions $\gamma e^{\pm} \to e^{\pm} \nu \bar \nu$ and $\gamma \gamma \to \nu \bar \nu$ are obtained. In the case of a cold degenerate plasma contributions of the considering processes to neutrino emissivity are calculated. It is shown that contribution of the process $\gamma \gamma \to \nu \bar \nu$ to neutrino emissivity is supressed in comparision with the contributions of the processes $\gamma e^{\pm} \to e^{\pm} \nu \bar \nu$ and $\gamma \to \nu \bar \nu$. The constraint on the magnetic field strength in the magnetar outer crust is obtained.Comment: 8 pages, LaTeX, 2 PS figures, based on the talk presented by D.A. Rumyantsev at the XV International Seminar Quarks'2008, Sergiev Posad, Moscow Region, May 23-29, 2008, to appear in the Proceeding

QCL active region overheat in pulsed mode: effects of non-equilibrium heat dissipation on laser performance

Quantum cascade lasers are of high interest in the scientific community due to unique applications utilizing the emission in mid-IR range. The possible designs of QCL are quite limited and require careful engineering to overcome some crucial disadvantages. One of them is an active region (ARn) overheat, that significantly affects the laser characteristics in the pulsed operation mode. In this work we consider the effects related to the non-equilibrium temperature distribution, when thermal resistance formalism is irrelevant. We employ the heat equation and discuss the possible limitations and structural features stemming from the chemical composition of the AR. We show that the presence of alloys in the ARn structure fundamentally limits the heat dissipation in pulsed and CW regimes due to their low thermal conductivity. Also the QCL post-growths affects the thermal properties of a device only in (near)CW mode while it is absolutely invaluable in the pulsed mod

Diagnosis of Cervical Cancer Using Raman Spectroscopy

The aim of the study was to develop a method of detecting cervical cancer using Raman spectroscopy in the examination of biopsy and surgical material. Significant differences in the spectral characteristics between the tissues of the intact cervix and tissues with squamous cell carcinoma of the cervix have been revealed. Intensity of fluorescence in cervical cancer was higher than in intact cervical tissue.     Keywords: cervical cancer, squamous cell carcinoma, diagnosis of cervical cancer, fluorescence in cervical cancer, Raman spectroscopy for the diagnosis of cervical cance

Free-space subcarrier wave quantum communication

We experimentally demonstrate quantum communication in 10 dB loss outdoor atmospheric channel with 5 kbit/s bitrate using subcarrier wave coding method. Free-space link was organized by telescoping system with symmetric fiber-optic collimators

Organizational factors for manufacturing defects reduction in small batch production

The study is devoted to the defects organizational causes analysis in the machine building products production process. The companies with the small batch production were taken into consideration. Factors related to the time norms fulfilling percentage, the work rhythm, the consolidation of operations at one workplace, the new technologies introduction and equipment failures were chosen. A preliminary factors selection according to independence criteria allowed us to build a reliable regression model for the defects rate calculating. The main factors influencing the defects rate in small batch production are the time norms fulfilling percentage, the rate of consolidation of operations at one workplace, and the number of new technological processes introduced. This allowed us to offer recommendations on the machining sites work organization. The final operations and productswhich are made from expensive metals should be carried out at workplaces with a low rate of operations consolidation. Also, it is important that the wage system should not contribute to over-fulfillment of norms. The maintenance and repair system should prevent malfunctions during operations fulfilment. © Published under licence by IOP Publishing Ltd

Solving Grid Equations Using the Alternating-triangular Method on a Graphics Accelerator

The paper describes a parallel-pipeline implementation of solving grid equations using the modified alternating-triangular iterative method (MATM), obtained by numerically solving the equations of mathematical physics. The greatest computational costs at using this method are on the stages of solving a system of linear algebraic equations (SLAE) with lower triangular and upper non-triangular matrices. An algorithm for solving the SLAE with a lower triangular matrix on a graphics accelerator using NVIDIA CUDA technology is presented. To implement the parallel-pipeline method, a three-dimensional decomposition of the computational domain was used. It is divided into blocks along the y coordinate, the number of which corresponds to the number of GPU streaming multiprocessors involved in the calculations. In turn, the blocks are divided into fragments according to two spatial coordinates — x and z. The presented graph model describes the relationship between adjacent fragments of the computational grid and the pipeline calculation process. Based on the results of computational experiments, a regression model was obtained that describes the dependence of the time for calculation one MATM step on the GPU, the acceleration and efficiency for SLAE solution with a lower triangular matrix by the parallel-pipeline method on the GPU were calculated using the different number of streaming multiprocessors.The paper describes a parallel-pipeline implementation of solving grid equations using the modified alternating-triangular iterative method (MATM), obtained by numerically solving the equations of mathematical physics. The greatest computational costs at using this method are on the stages of solving a system of linear algebraic equations (SLAE) with lower triangular and upper non-triangular matrices. An algorithm for solving the SLAE with a lower triangular matrix on a graphics accelerator using NVIDIA CUDA technology is presented. To implement the parallel-pipeline method, a three-dimensional decomposition of the computational domain was used. It is divided into blocks along the y coordinate, the number of which corresponds to the number of GPU streaming multiprocessors involved in the calculations. In turn, the blocks are divided into fragments according to two spatial coordinates — x and z. The presented graph model describes the relationship between adjacent fragments of the computational grid and the pipeline calculation process. Based on the results of computational experiments, a regression model was obtained that describes the dependence of the time for calculation one MATM step on the GPU, the acceleration and efficiency for SLAE solution with a lower triangular matrix by the parallel-pipeline method on the GPU were calculated using the different number of streaming multiprocessors