Performance of efficient Q-switched diode-laser-pumped Nd:YAG and Ho:YLF lasers for space applications

Solid-state lasers pumped by continuous-wave diode lasers can be Q-switched to obtain high peak power output pulses. The dependence of laser-pulse energy, average output power, peak power, and pulse width on pulse-repetition frequency in Q-switched Nd:YAG and Ho:YLF lasers is determined and compared. At low pulse repetition rates, the much longer upper-stage lifetime in Ho:YLF gives a distinct advantage. At higher pulse rates, the overall laser efficiency and the stimulated emission cross section are more important parameters, leading to an advantage for Nd:YAG. The results are of significance for designing lasers for use in space optical communications and remote sensing systems

Wave Profile for Current Bearing Antiforce Waves

For fluid dynamical analysis of breakdown waves, we employ a one-dimensional, three-component (electrons, ions and neutral particles) fluid model to describe a steady-state, ionizing wave propagating counter to strong electric fields. The electron gas temperature and therefore the electron fluid pressure is assumed to be large enough to sustain the wave motion down the discharge tube. Such waves are referred to as antiforce waves. The complete set of equations describing such waves consists of the equations of conservation of mass, momentum and energy coupled with Poisson’s equation. Inclusion of current behind the wave front alters the set of electron fluid dynamical equations and also the boundary condition on electron temperature. For a range of experimentally observed current values, using the modified boundary condition on electron temperature, we have been able to integrate our modified set of electron fluid dynamical equations through the Debye layer. Our solutions meet the expected boundary conditions at the trailing edge of the wave. We present the wave profile for electric field, electron velocity, electron number density and electron temperature within the Debye layer of the wave

Phase behavior of UCST blends: Effects of pristine nanoclay as an effective or ineffective compatibilizer

The effects of unmodified nanoclay (natural montmorillonite) on the miscibility, phase behavior and phase separation kinetics of polyethylene (PE)/ethylene vinyl acetate copolymer (EVA) blends have been investigated. Depending on the blend composition, it was observed that the intercalated pristine nanoclay influences the biphasic morphology either as an effective compatibilizer or just as an ineffectual modifier. In spite of the presence of micrometer-sized agglomerated tactoids, natural nanoclay can play a thermodynamic role in reducing the interfacial tension of polymer components. The addition of clay nanoparticles was found to change the phase diagram slightly and diminishes the composition dependency of the binodal temperatures. Moreover, it was observed that a small amount of unmodified layered silicate slows down the phase separation process considerably and enhances the solubility of each polymer in the domains of its counterpart. The findings of this study verify that even poorly dispersed nanoclay with high surface tension can act as a conventional compatibilizer and change the immiscible PE/EVA blends to the partially miscible ones

Efficient Optimal Minimum Error Discrimination of Symmetric Quantum States

This paper deals with the quantum optimal discrimination among mixed quantum states enjoying geometrical uniform symmetry with respect to a reference density operator $\rho_0$. It is well-known that the minimal error probability is given by the positive operator-valued measure (POVM) obtained as a solution of a convex optimization problem, namely a set of operators satisfying geometrical symmetry, with respect to a reference operator $\Pi_0$, and maximizing $\textrm{Tr}(\rho_0 \Pi_0)$. In this paper, by resolving the dual problem, we show that the same result is obtained by minimizing the trace of a semidefinite positive operator $X$ commuting with the symmetry operator and such that $X >= \rho_0$. The new formulation gives a deeper insight into the optimization problem and allows to obtain closed-form analytical solutions, as shown by a simple but not trivial explanatory example. Besides the theoretical interest, the result leads to semidefinite programming solutions of reduced complexity, allowing to extend the numerical performance evaluation to quantum communication systems modeled in Hilbert spaces of large dimension.Comment: 5 pages, 1 Table, no figure

Effect of IT Application on Project Performance Focusing on the Mediating Role of Organizational Innovation, Knowledge Management and Organizational Capabilities

The purpose of this study is to examine the effect of IT application on project performance focusing on mediating role of organizational innovation, knowledge management and organizational capabilities using SEM. For this purpose, 194 managers, supervisors and experts of software developer companies participated in this study. Participants were asked to complete a questionnaire on each subject. SEM was used to analyze data using the LISREL software. Results are thoroughly discussed in this paper and the findings support the role of IT application, organizational innovation, knowledge management and organizational capabilities on project performance and project benefits

CANDELS Multi-wavelength Catalogs: Source Identification and Photometry in the CANDELS COSMOS Survey Field

We present a multi-wavelength photometric catalog in the COSMOS field as part of the observations by the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey. The catalog is based on Hubble Space Telescope Wide Field Camera 3 (HST/WFC3) and Advanced Camera for Surveys observations of the COSMOS field (centered at R.A.: 10^h00^m28^s, Decl.:+02^º12^'21^"). The final catalog has 38671 sources with photometric data in 42 bands from UV to the infrared (~ 0.3-8 µm). This includes broadband photometry from HST, CFHT, Subaru, the Visible and Infrared Survey Telescope for Astronomy, and Spitzer Space Telescope in the visible, near-infrared, and infrared bands along with intermediate- and narrowband photometry from Subaru and medium-band data from Mayall NEWFIRM. Source detection was conducted in the WFC3 F160W band (at 1.6 μm) and photometry is generated using the Template FITting algorithm. We further present a catalog of the physical properties of sources as identified in the HST F160W band and measured from the multi-band photometry by fitting the observed spectral energy distributions of sources against templates

Economic value added of intellectual capital on the market value of listed companies in Tehran Stock Exchange

The present research studies the effects of the economic value added (EVA) and the intellectual capital on value of the listed companies’ value in Tehran Stock Exchange. The research was based on an applicable goal and it is descriptive and post-event in terms of nature. The sample of the research consists of 89 companies listed in Tehran Stock Exchange and the research period was from 2004 to 2011. In order to examine the research hypothesis, a multivariate regression is utilized using panel data. The results indicate spontaneous use of intellectual capital variable and the remaining profit according to the accepted principles of accounting increase description power of the market value fluctuations of the corporate remarkably

Economic value added of intellectual capital on the market value of listed companies in Tehran Stock Exchange

The present research studies the effects of the economic value added (EVA) and the intellectual capital on value of the listed companies’ value in Tehran Stock Exchange. The research was based on an applicable goal and it is descriptive and post-event in terms of nature. The sample of the research consists of 89 companies listed in Tehran Stock Exchange and the research period was from 2004 to 2011. In order to examine the research hypothesis, a multivariate regression is utilized using panel data. The results indicate spontaneous use of intellectual capital variable and the remaining profit according to the accepted principles of accounting increase description power of the market value fluctuations of the corporate remarkably

Economic value added of intellectual capital on the market value of listed companies in Tehran Stock Exchange

The present research studies the effects of the economic value added (EVA) and the intellectual capital on value of the listed companies’ value in Tehran Stock Exchange. The research was based on an applicable goal and it is descriptive and post-event in terms of nature. The sample of the research consists of 89 companies listed in Tehran Stock Exchange and the research period was from 2004 to 2011. In order to examine the research hypothesis, a multivariate regression is utilized using panel data. The results indicate spontaneous use of intellectual capital variable and the remaining profit according to the accepted principles of accounting increase description power of the market value fluctuations of the corporate remarkably

Low Speed Current Bearing Anti-force Waves

For theoretical investigation of electrical breakdown of a gas, we apply a one-dimensional, steady profile, constant velocity, three-component (electrons, ions and neutral particles) fluid model. Our fluid model consists of the equations of conservation of mass, momentum and energy, coupled with the Poison’s equation. The set of equations is referred to as the electron fluid dynamical equations (EFD). This investigation involves breakdown waves with a substantial current behind the wave front, and waves for which the electric field force on electrons is in the opposite direction of the wave propagation (anti-force waves – lightning return stroke). Therefore, the set of electron fluid dynamical equations need to be modified. For a low wave speed, we intend to find current values, and also the maximum current, for which solutions for our set of electron fluid dynamical equations become possible