5,287 research outputs found

    Business Incubators: Creation of a Fit in Armenia

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    In this paper, we evaluate the extent to which business incubation services meet tenant’s needs. Additionally, we pose the question of whether the current business incubators actually cover the needs of a particular industry. Our empirical setting is a developing country in the Caucasian Region (Armenia) and we chose to research solely the IT industry. We employed a two stage procedure: first, we conducted interviews with pivotal people familiar with business incubation in Armenia; second, an electronic questionnaire survey was sent to the entire Armenian IT population. The results suggest a moderate need of IT companies for the typical business incubation services. Further, we show that incubated companies are generally satisfied with the services they enjoy albeit this satisfaction level decreases as the needs increase. Non-incubated companies, on the other hand, perceive incubation services to be valuable for their development and this value increases when their needs increase. Our study implies that a more extensive service provision is necessary to fully cover the needs of the Armenian IT industry for business incubation services

    New perturbative solutions of the Kerr-Newman dilatonic black hole field equations

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    This work describes new perturbative solutions to the classical, four-dimensional Kerr--Newman dilaton black hole field equations. Our solutions do not require the black hole to be slowly rotating. The unperturbed solution is taken to be the ordinary Kerr solution, and the perturbation parameter is effectively the square of the charge-to-mass ratio (Q/M)2(Q/M)^2 of the Kerr--Newman black hole. We have uncovered a new, exact conjugation (mirror) symmetry for the theory, which maps the small coupling sector to the strong coupling sector (ϕ→−ϕ\phi \to -\phi). We also calculate the gyromagnetic ratio of the black hole.Comment: Revtex, 27 page

    Hearing in the Juvenile Green Sea Turtle (Chelonia mydas): A Comparison of Underwater and Aerial Hearing Using Auditory Evoked Potentials

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    Sea turtles spend much of their life in aquatic environments, but critical portions of their life cycle, such as nesting and hatching, occur in terrestrial environments, suggesting that it may be important for them to detect sounds in both air and water. In this study we compared underwater and aerial hearing sensitivities in five juvenile green sea turtles (Chelonia mydas) by measuring auditory evoked potential responses to tone pip stimuli. Green sea turtles detected acoustic stimuli in both media, responding to underwater stimuli between 50 and 1600 Hz and aerial stimuli between 50 and 800 Hz, with maximum sensitivity between 200 and 400 Hz underwater and 300 and 400 Hz in air. When underwater and aerial hearing sensitivities were compared in terms of pressure, green sea turtle aerial sound pressure thresholds were lower than underwater thresholds, however they detected a wider range of frequencies underwater. When thresholds were compared in terms of sound intensity, green sea turtle sound intensity level thresholds were 2–39 dB lower underwater particularly at frequencies below 400 Hz. Acoustic stimuli may provide important environmental cues for sea turtles. Further research is needed to determine how sea turtles behaviorally and physiologically respond to sounds in their environment

    Seismic topographic scattering in the context of GW detector site selection

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    In this paper, we present a calculation of seismic scattering from irregular surface topography in the Born approximation. Based on US-wide topographic data, we investigate topographic scattering at specific sites to demonstrate its impact on Newtonian-noise estimation and subtraction for future gravitational-wave detectors. We find that topographic scattering at a comparatively flat site in Oregon would not pose any problems, whereas scattering at a second site in Montana leads to significant broadening of wave amplitudes in wavenumber space that would make Newtonian-noise subtraction very challenging. Therefore, it is shown that topographic scattering should be included as criterion in the site-selection process of future low-frequency gravitational-wave detectors.Comment: 16 pages, 7 figure

    A statistical exploration of interval-deficient wind speed data for application to wind power assessments

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    Gathering quality wind speed data can be time-consuming and expensive. The present study established whether interval-deficient wind speed data could be rendered useful for wind power assessments. The effect of interval deficiency on the quality of the wind speed data was investigated by studying the behaviour of the Weibull scale and shape factors as the interval size between wind speed measurements increased. Five wind speed data sets obtained from the Southern African Universities Radiometric Network (Sauran) were analysed, based on a proposed procedure to find the true Weibull parameters from an interval-deficient wind speed data set. It was found that the relative errors in the Weibull parameters were, on average, less than 1%, compared with the Weibull parameters computed from a wind speed data set that complies with the IEC 61400-12-1:2005(E) standard. This finding may contribute to time and cost reduction in wind power assessments. It may also promote the application of statistical methods in the renewable energy sector

    Theoretical survey of tidal-charged black holes at the LHC

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    We analyse a family of brane-world black holes which solve the effective four-dimensional Einstein equations for a wide range of parameters related to the unknown bulk/brane physics. We first constrain the parameters using known experimental bounds and, for the allowed cases, perform a numerical analysis of their time evolution, which includes accretion through the Earth. The study is aimed at predicting the typical behavior one can expect if such black holes were produced at the LHC. Most notably, we find that, under no circumstances, would the black holes reach the (hazardous) regime of Bondi accretion. Nonetheless, the possibility remains that black holes live long enough to escape from the accelerator (and even from the Earth's gravitational field) and result in missing energy from the detectors.Comment: RevTeX4, 12 pages, 4 figures, 5 tables, minor changes to match the accepted version in JHE

    Injection of liquids into the soil with a high-pressure jet

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    With regard to injection fertilizing, the more general topic of liquid injection into the soil with the aid of a high-pressure jet is of great importance.  Injection fertilizing means that liquid fertilizer is injected into the soil near the plant roots.  This provides many agronomical advantages.  However, currently available mechanical injection fertilizing techniques in the field use have some disadvantages, such as very heavy wear on individual components.  Therefore, research on the direct, contactless injection of liquids into the soil with the aid of a high-pressure jet is being carried out at the Institute of Agricultural Machinery and Fluid Power of the Technische Universitaet of Braunschweig.  The potential and the possibilities of injection by a high-pressure jet are being examined in trials on a stationary test rig.  In these trials, different soils were used under different conditions (soil moisture, and soil density), and the possibilities of injecting pure water in the form of a high-pressure water jet were studied.  It was shown that the variation of different parameters of the high-pressure jet, such as water pressure, volume flow, etc., allow different injection depths in the soil to be realized.  Especially soil moisture has a very great influence on injection.  In dry soils, for example, the binding forces of the soil bodies (solid body bridges, van-der-Waals forces, etc.) are very strong so that only small injection depths can be reached.  The higher the degree of soil moisture is, the larger the injection depth becomes.  Depending on the soil type, average soil moisture, water pressure of 40 MPa, and speed of the nozzle over the ground of 2 m/s provide injection depths of 70 – 90 mm.  In addition to application in the area of injection fertilizing, the considered injection of liquids into the soil also shows great potential in plant protection, irrigation, as well as the injection of decontamination agents into contaminated soils.Keywords: injection of liquids, soil, fertilisation, high pressure, contactless, frictionles
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