991 resultados para open-top chambers
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This paper discusses the use of a university spin-out firm to bring a potentially disruptive technology to market. The focus for discussion is how a spin-out can build a technology ecosystem of providers of complementary resources to enable partner organizations to build competence in a novel and potentially disruptive technology. The paper uses the illustrative case of Cambridge Display Technology Ltd (CDT) to consider these issues from the perspective of the literature on open innovation (with particular emphasis on the role of partnerships between start-ups and established firms), the commercialization of university IP, and the commercialization of disruptive technologies. © World Scientific Publishing Company.
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© 2014 IEEE. This exploratory study addresses a gap in management literature by addressing the role of location in the continuously expanding field of open innovation research. In this context, we analyze potential negative effects of absolute geography and relative proximity on open innovation practices in high-tech small and medium-sized enterprises (SMEs) in the United Kingdom. Drawing upon cluster theory and business ecosystem literature, the analysis from three SME case studies in the East of England suggests that presumed 'favorable' location variables, such as close relative proximity between partners and the presence of economic clusters, can have certain negative effects on open innovation practices.
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A twin-shaped constructed wetland (CW) comprising a vertical flow (inflow) chamber with Cyperus alternifolius followed by a reverse-vertical flow (outflow) chamber with Villarsia exaltata was assessed for decontamination of artificial wastewater polluted by heavy metals. After application of Cd, Cu, Pb, Zn over 150 days, together with Al and Mn during the final 114 days, no heavy metals with the exception of Mn could be detected in either the drainage zone at the bottom, shared by both chambers, or in the effluent. The inflow chamber was, therefore, seen to be predominantly responsible for the decontamination process of more toxic metal species with final concentrations far below WHO drinking-water standards. About one-third of the applied Cu and Mn was absorbed, predominantly by lateral roots of C. alternifolius. Lower accumulation levels were observed for Zn (5%), Cd (6%), Al (13%). and Pb (14%). Contents of Cd, Cu, Mn, and Zn in soil were highest in top layer, while Al and Pb were evenly distributed through the whole soil column. Metal species accumulating mainly in the top layer can be removed mechanically. A vertical flow CW with C. alternifolius is an effective tool in phytoremediation for treatment of water polluted with heavy metals. (C) 2002 Elsevier Science B.V. All rights reserved.
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Electrically pumped, edge-emitting, singlemode operation of a two-dimensional photonic crystal distributed feedback (PCDFB) quantum cascade laser emitting at similar to 7.8 mu m is demonstrated. The two-beam holographic technique combined with wet-etching process is successfully used to de. ne a square-lattice PCDFB structure on the top grating layer of the laser. This simple PC fabrication method may open exciting opportunities for the wide application of PCDFB lasers.
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In the optical network, the quick and accurate alignment with wavelength is an important issue during the channel detection. At this point, a filter having flat-top response characteristic is an effective solution. Based on multiple-step-type Fabry-Perot cavity structure, a novel all-Si-based thermooptical tunable flat-top filter with narrow-band has been fabricated, using our patent silicon-on-reflector bonding technology. The device demonstrated a 1-dB flat-top width of 1 nm, 3-dB band of 3 nm, free spectra range of 8 nm, and the tuning range of 4.6 nm was obtained under the applied voltage of 4 V.
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The effect of implanting nitrogen into buried oxide on the top gate oxide hardness against total irradiation does has been investigated with three nitrogen implantation doses (8 x 10(15), 2 x 10(16) and 1 x 10(17) cm(-2)) for partially depleted SOI PMOSFET. The experimental results reveal the trend of negative shift of the threshold voltages of the studied transistors with the increase of nitrogen implantation dose before irradiation. After the irradiation with a total dose of 5 x 10(5) rad(Si) under a positive gate voltage of 2V, the threshold voltage shift of the transistors corresponding to the nitrogen implantation dose 8 x 10(15) cm(-2) is smaller than that of the transistors without implantation. However, when the implantation dose reaches 2 x 10(16) and 1 x 10(17) cm(-2), for the majority of the tested transistors, their top gate oxide was badly damaged due to irradiation. In addition, the radiation also causes damage to the body-drain junctions of the transistors with the gate oxide damaged. All the results can be interpreted by tracing back to the nitrogen implantation damage to the crystal lattices in the top silicon.
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A 40-channel 0.8-nm-spaced flat-top silica-based arrayed waveguide grating (AWG) with a tapered multimode interferometer (MMI) at the end of its input waveguide has been experimentally demonstrated for the first time. By adding the MMI, the 1-dB and 3-dB bandwidths are increased to 0.45 and 0.62 nm, respectively. The insertion loss (IS) of the device ranges from 3.8 to 6.8 dB. The IS uniformity is better than 3.0 dB. The crosstalk is better than -25 dB. Compared to the AWG with a rectangular MMI, the AWG with a tapered MMI shows better IS, crosstalk, and ripple. (c) 2006 Society of Photo-Optical Instrumentation Engineers.
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By viewing the non-equilibrium transport setup as a quantum open system, we propose a reduced-density-matrix based quantum transport formalism. At the level of self-consistent Born approximation, it can precisely account for the correlation between tunneling and the system internal many-body interaction, leading to certain novel behavior such as the non-equilibrium Kondo effect. It also opens a new way to construct time-dependent density functional theory for transport through large-scale complex systems. (c) 2006 Elsevier B.V. All rights reserved.
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This paper reports the study on a field-aided collection in p-on-n GaInP2 top cells. The cells were produced by metalorganic vapor phase epitaxy at a low gas pressure. In order to optimize the device configuration, numerical simulations have been performed for the impacts of field-aided collection on the performance of the top cells. On the basis of the modeling results, a modified p(+)-p(-)-n(-)-n(+) configuration is introduced for GaInP2 top cells. This modification has brought out improved photovoltaic performance of the top cells, with conversion efficiency EFF = 14.26% (AM0, 2 x 2 cm(2), 25degreesC). (C) 2003 Elsevier B.V. All rights reserved.
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Reliable messaging is a key component necessary for mobile agent systems. Current researches focus on reliable one-to-one message delivery to mobile agents. But how to implement a group communication system for mobile agents remains an open issue, which is a powerful block that facilitates the development of fault-tolerant mobile agent systems. In this paper, we propose a group communication system for mobile agents (GCS-MA), which includes totally ordered multicast and membership management functions. We divide a group of mobile agents into several agent clusters,and each agent cluster consists of all mobile agents residing in the same sub-network and is managed by a special module, named coordinator. Then, all coordinators form a ring-based overlay for interchanging messages between clusters. We present a token-based algorithm, an intra-cluster messaging algorithm and an inter-cluster migration algorithm to achieve atomicity and total ordering properties of multicast messages, by building a membership protocol on top of the clustering and failure detection mechanisms. Performance issues of the proposed system have been analysed through simulations. We also describe the application of the proposed system in the context of the service cooperation middleware (SCM) project.
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High speed visualizations and thermal performance studies of pool boiling heat transfer on copper foam covers were performed at atmospheric pressure, with the heating surface area of 12.0 mm by 12.0 mm, using acetone as the working fluid. The foam covers have ppi (pores per inch) from 30 to 90, cover thickness from 2.0 to 5.0 mm, and porosity of 0.88 and 0.95. The surface superheats are from -20 to 190 K, and the heat fluxes reach 140 W/cm(2). The 30 and 60 ppi foam covers show the periodic single bubble generation and departure pattern at low surface superheats. With continuous increases in surface superheats, they show the periodic bubble coalescence and/or re-coalescence pattern. Cage bubbles were observed to be those with liquid filled inside and vented to the pool liquid. For the 90 ppi foam covers, the bubble coalescence takes place at low surface superheats. At moderate or large surface superheats, vapor fragments continuously escape to the pool liquid. Boiling curves of copper foams show three distinct regions. Region I and II are those of natural convection heat transfer, and nucleate boiling heat transfer for all the foam covers. Region III is that of either a resistance to vapor release for the 30 and 60 ppi foam covers, or a capillary-assist liquid flow towards foam cells for the 90 ppi foam covers. The value of ppi has an important effect on the thermal performance. Boiling curves are crossed between the high and low ppi foam covers. Low ppi foams have better thermal performance at low surface superheats, but high ppi foams have better one at moderate or large surface superheats and extend the operation range of surface superheats. The effects of other factors such as pool liquid temperature, foam cover thickness on the thermal performance are also discussed.