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Now showing items 1 - 16 of 112

  • Monolayer Doping of Si with Improved Oxidation Resistance

    O'Connell, John   Collins, Gillian   McGlacken, Gerard P.   Duffy, Ray   Holmes, Justin D.  

    In this article, the functionalization of planar silicon with arsenic- and phosphorus-based azides was investigated. Covalently bonded and well-ordered alkyne-terminated monolayers were prepared from a range of commercially available dialkyne precursors using a well-known thermal hydrosilylation mechanism to form an acetylene-terminated monolayer. The terminal acetylene moieties were further functionalized through the application of copper-catalyzed azide-alkyne cycloaddition (CuAAC) reactions between dopant-containing azides and the terminal acetylene groups. The introduction of dopant molecules via this method does not require harsh conditions typically employed in traditional monolayer doping approaches, enabling greater surface coverage with improved resistance toward reoxidation. X-ray photoelectron spectroscopy studies showed successful dialkyne incorporation with minimal Si surface oxidation, and monitoring of the C is and N is core-level spectra showed successful azide-alkyne cycloaddition. Electrochemical capacitance-voltage measurements showed effective diffusion of the activated dopant atoms into the Si substrates.
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  • Organo-arsenic Molecular Layers on Silicon for High-Density Doping

    O'Connell, John   Verni, Giuseppe Alessio   Gangnaik, Anushka   Shayesteh, Maryam   Long, Brenda   Georgiev, Yordan M.   Petkov, Nikolay   McGlacken, Gerard P.   Morris, Michael A.   Duffy, Ray   Holmes, Justin D.  

    This article describes for the first time the controlled monolayer doping.(ID) of bulk and nanostructured crystalline silicon with As at concentrations approaching 2 x 10(20) atoms cm(-3). Characterization of doped structures after the MLD process confirmed that they remained defect- and damage-free, with no indication of increased roughness or a,change in morphology. Electrical characterization of the doped substrates and nanowire test structures allowed determination of resistivity, sheet resistance, and active doping levels. Extremely high As-doped Si substrates and nanowire devices could be obtained and controlled using specific capping and annealing steps, Significantly, the As-doped nanowires exhibited resistances several orders of magnitude lower than the predoped materials.
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  • Marsh bird occupancy of wetlands managed for waterfowl in the Midwestern USA

    Bradshaw, Therin M.   Blake-Bradshaw, Abigail G.   Lancaster, Joseph D.   O'Connell, John   Jacques, Christopher N.   Eichholz, Michael W.   Hagy, Heath M.  

    Marsh birds (rallids, bitterns, and grebes) depend on emergent wetlands, and habitat loss and degradation are the primary suspected causes for population declines among many marsh bird species. We evaluated the effect of natural wetland characteristics, wetland management practices, and surrounding landscape characteristics on marsh bird occupancy in Illinois during late spring and early summer 2015-2017. We conducted call-back surveys following the North American Standardized Marsh Bird Survey Protocol three times annually at all sites (2015 n =3D 49, 2016 n =3D 57, 2017 n =3D 55). Across all species and groups, detection probability declined 7.1% +/- 2.1 each week during the marsh bird survey period. Wetlands managed for waterfowl (ducks, geese, and swans) had greater occupancy than reference wetlands. Marsh bird occupancy increased with greater wetland complexity, intermediate levels of waterfowl management intensity, greater proportions of surface water inundation, and greater proportions of persistent emergent vegetation cover. Wetland management practices that retain surface water during the growing season, encourage perennial emergent plants (e.g., Typha sp.), and increase wetland complexity could be used to provide habitat suitable for waterfowl and marsh birds.
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  • Revisiting Analysis of Phthalate Plasticizers Concentration in Poly(vinyl chloride)

    Krongauz, Vadim V.   Ling, Michael T. K.   O'Connell, John  

    The method of the efficient analysis of di(2-diethyl-hexyl) phthalate, tri(2-ethylhexyl) trimellitate, di(2-ethylhexyl) terephthalate, and other phthalate plasticizers concentrations in plasticized poly(vinyl chloride) (PVC) was developed. The method is based on quantitative dissolution of the PVC sample in methyl ethyl ketone with the consequent precipitation of PVC with hexane and concentration of phthalate in an organic layer. A capillary column-based gas chromatographic technique for phthalates separation and quantification was developed and used in conjunction with the PVC and phthalates dissolution technique. The developed method of phthalate plasticizers analysis proved to be relatively fast, reproducible, and straightforward. (C) 2014 Society of Plastics Engineers
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  • Small molecule inhibitors of HIV RT Ribonuclease H

    Olson, Matthew   Prashad, Amar S.   Bebernitz, Geraldine   Luckay, Amara   Mullen, Stanley   Hu, Yongbo   Krishnamurthy, Girija   Pitts, Keith   O'Connell, John  

    Two classes of compounds, thiocarbamates 1 and triazoles 2, have been identified as HIV RT RNase H inhibitors using a novel FRET-based HTS assay. The potent analogs in each series exhibited selectivity and were active in cell-based assays. In addition, saturable, 1: 1 stoichiometric binding to target was established and time of addition studies were consistent with inhibition of RT-mediated HIV replication. (C) 2009 Elsevier Ltd. All rights reserved.
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  • Sharing Enriched Multimedia Experiences across Heterogeneous Network Infrastructures

    Hesselman, Cristian   Abbadessa, Daniele   van der Beek, Wouter   Gorgen, Daniel   Shepherd, Keir   Smit, Sander   Guelbahar, Mark   Vaishnavi, Ishan   Zoric, Josip   Lowet, Dietwig   de Groote, Robert   O'Connell, John   Friedrich, Oliver  

    Today's consumers have a wide variety of interactive media and services at their disposal, for instance, through IPTV networks, the Internet, and in-home and mobile networks. A major problem, however, is that media and services do not interoperate across networks because they use different user identities, metadata formats, and signaling protocols, for example. As a result, users cannot easily combine media and services from different network infrastructures and share them in an integrated manner with their family and friends. In addition to limiting people's media experience, this also hinders the introduction of new services and business models as providers cannot easily develop and operate cross-network services. The goal of our work is to overcome this problem by means of an open and intelligent service platform that allows applications to easily combine media and services from different network infrastructures, and enables consumers to easily share them in an integrated way. The platform includes support for managing multi-user sessions across networks, context-aware recommendations, and cross-network identity management. While there has been prior work on platforms for converged media, our platform is unique in that it provides open, intelligent, and interoperable facilities for sharing media and services across network infrastructures. In addition, our work involves several specific innovations, for instance, pertaining to cross-network session management and synchronization. In this article we discuss the platform, its most important enabling services, and some of the applications we have built on top of it. We also briefly consider the new kinds of business models our platform makes possible.
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  • Regulated phase separation in nanopatterned protein-polysaccharide thin films by spin coating

    Banta, Russell A.   Collins, Timothy W.   Curley, Ricky   O'Connell, John   Young, Paul W.   Holmes, Justin D.   Flynn, Eoin J.  

    Patterned films are essential to the commonplace technologies of modern life. However, they come at high cost to the planet, being produced from non-renewable, petrochemical-derived polymers and utilising substrates that require harsh, top-down etching techniques. Biopolymers offer a cheap, sustainable and viable alternative easily integrated into existing production techniques. We describe a simple method for the production of patterned biopolymer surfaces and the assignment of each biopolymer domain, which allows for selective metal incorporation used in many patterning applications. Protein and polysaccharide domains were identified by selective etching and metal incorporation; a first for biopolymer blends. Morphologies akin to those observed with synthetic polymer blends and block-copolymers were realised across a large range of feature diameter (200 nm to - 20 mu m) and types (salami structure, continuous, porous and droplet-matrix). The morphologies of the films were tuneable with simple recipe changes, highlighting that these biopolymer blends are a feasible alternative to traditional polymers when patterning surfaces. The protein to polysaccharide ratio, viscosity, casting method and spin speed were found to influence the final film morphology. High protein concentrations generally resulted in porous structures whereas higher polysaccharide concentrations resulted in spherical discontinuous domains. Low spin speed conditions resulted in growth of protuberances ranging from 200 nm to 22 mu m in diameter, while higher spin speeds resulted in more monodisperse features, with smaller maximal diameter structures ranging from 300 nm to 12.5 mu m.
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    The invention focusses on providing services (3) originating from a plurality of services (3a, 3b) through one centrel network element (4), which may be integrated in a gateway. The network element performs a method comprising: - combining pluralities of independent service elements (3a, 3b) to form respective service compositions; - providing a plurality of service chaining applications, each of said service chaining applications being associated with one of said service compositions and defining a set of network and/or user events associated with actions for controlling the independent service elements (3a, 3b) of the corresponding service composition; wherein upon triggering of at least one service composition said method further comprises: - identifying and executing a corresponding service chaining application to manage instances of the independent service elements (3a, 3b) comprised in said service composition in accordance with current network and/or user events; and - managing said network resources and said network services in accordance with a totality of current instances of independent service elements (3a, 3b).
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    According to one aspect of the present invention, there is provided a method of charging a plurality of subscribers (102, 104, 106) of a communication system for shared use of a group service (204), each user being chargeable through a billing system (116, 118), comprising determining a charging policy to be applied during the use of the service, and causing a user (102, 104, 106) to be charged through their respective billing system (116, 118) for their respective use of the service in accordance with the charging policy.
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  • Service Delivery within an IMS Environment

    O'Connell, John  

    The IP Multimedia Subsystem (IMS) standard is being widely adopted by both wireline and wireless service providers to support the next wave of multimedia communication applications. As currently defined, that IMS standard proposes a detailed architecture for the transport and control layers of the next-generation telecommunication networks, but leaves many questions unanswered on how the application layer should be structured. A more structured approach to service delivery will be required in order to deliver new multi-media applications in an efficient and cost-effective way. An approach based on Service Delivery Platform (SDP) proposes a layered service architecture, with a strong emphasis on re-use of common service enablers and on open APIs. This paper describes work being undertaken within HP's IMS Experience Center to validate a horizontal service delivery architecture for next-generation IP multi-media applications.
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  • A Hybrid Integrated Services Digital Network-Internet Protocol Solution for Resident Education

    Erickson, Delnora   Greer, Lester   Belard, Arnaud   Tinnel, Brent   O'Connell, John  

    Objective: The purpose of this study was to explore the effectiveness of incorporating Web-based application sharing of virtual medical simulation software within a multipoint video tele-conference (VTC) as a training tool in graduate medical education. Materials and Methods: National Capital Consortium Radiation Oncology Residency Program resident and attending physicians participated in dosimetry teaching sessions held via VTC using Acrobat (R) Connect (TM) application sharing. Residents at remote locations could take turns designing radiation treatments using standard three-dimensional planning software, whereas instructors gave immediate feedback and demonstrated proper techniques. Immediately after each dosimetry lesson, residents were asked to complete a survey that evaluated the effectiveness of the session. At the end of a 3-month trial of using Adobe (R) Connect, residents completed a final survey that compared this teaching technology to the prior VTC alone method. Results: The mean difference from equality across all quality measures from the weekly survey was 0.8, where 0 indicated neither enhanced nor detracted from the learning experience and 1 indicated a minor enhancement in the learning experience. The mean difference from equality across all measures from the final survey comparing use of application sharing with VTC to VTC alone was 1.5, where 1 indicated slightly better and 2 indicated a somewhat better experience. Conclusions: The teaching efficacy of multipoint VTC is perceived by medical residents to be more effective when complemented by application-sharing software such as Adobe Acrobat Connect.
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  • Liquid-Phase Monolayer Doping of InGaAs with Si-,S-,and Sn-Containing Organic Molecular Layers

    O'Connell, John   Napolitani, Enrico   Impellizzeri, Giuliana   Glynn, Colm   McGlacken, Gerard P.   O'Dwyer, Colm   Duffy, Ray   Holmes, Justin D.  

    The functionalization and subsequent monolayer doping of In GaAs substrates using a tin-containing molecule and a compound containing both silicon and sulfur was investigated. Epitaxial InGaAs layers were grown on semi-insulating InP wafers and functionalized with both sulfur and silicon using mercaptopropyltriethoxysilane and with tin using allyltributylstannane. The functionalized surfaces were characterized using X-ray photoelectron spectroscopy (XPS). The surfaces were capped and subjected to rapid thermal annealing to cause in-diffusion of dopant atoms. Dopant diffusion was monitored using secondary ion mass spectrometry. Raman scattering was utilized to nondestructively determine the presence of dopant atoms, prior to destructive analysis, by comparison to a blank undoped sample. Additionally, due to the Asdominant surface chemistry, the resistance of the functionalized surfaces to oxidation in ambient conditions over periods of 24 h and 1 week was elucidated using XPS by monitoring the As 3d core level for the presence of oxide components.
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    A beverage product comprises a container holding a liquid beverage component and sufficient nitrogen gas to give a gas pressure in the head space of at least 3.3 bar at 5°C, said liquid beverage comprising an organoleptically acceptable foam-maintaining system such that when the liquid beverage is poured from the container a foam is generated,the volume of which is maintained at greater than 80% of its initial volume for a period of at least 10, preferably at least 30 minutes. The initial volume of the foam may be less than 20% of the volume of the liquid beverage. The foam-maintaining system may comprise octenylsuccinic acid modified starch, and at least one surface active agent selected from the group consisting of acyl lactylate salts, proteins, protein hydrolysates, sucrose esters, and mixtures thereof.
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    A beverage product comprises a container holding a liquid beverage component and nitrogen gas, said liquid beverage comprising octenylsuccinic acid modified starch, and at least one surface active agent selected from the group consisting of acyl lactylate salts, proteins, protein hydrolysates, sucrose esters and mixtures thereof.
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    Embodiments provide a communication method; the method comprising the steps of processing first data received from a first device; the data being associated with a first target device of an addressee; and processing second data received from the first device; the second data being associated with a second target device of an addressee. This method allows to convert the format of data exchanged between devices, e.g. between text and speech according to user preferences. It also allows to manage sessions spanning over several separated communication exchanges, including maintaining historical data associated with these exchanges.
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  • Fabrication of MoS2 Nanowire Arrays and Layered Structures via the Self-Assembly of Block Copolymers

    Chaudhari, Atul   Ghoshal, Tandra   Shaw, Matthew T.   O'Connell, John   Kelly, Roisin A.   Glynn, Colm   O'Dwyer, Colm   Holmes, Justin D.   Morris, Michael A.  

    The electronics industry is beginning to show interest in 2D molybdenum disulfide (2D-MoS2) as a potential device material due to its low band gap and high mobility. However, current methods for its synthesis are not "fab" friendly and require harsh environments and processes. Here, a novel method to prepare MoS2 nanowire arrays and layered structures via self-assembly of a block copolymer system is reported. Well-controlled films of microphase separated line-space nanopatterns have been achieved by solvent annealing process. The self-assembled films are used as "templates" for the generation of nonstoichometric molybdenum oxide by in situ inclusion technique following UV/Ozone treatment. Well-ordered array of MoS2 and a layered structure are then prepared by chemical vapor deposition using sulfur powder at lower temperature. The surface morphology, crystal structure, and phases are examined by different microscopic and spectroscopic techniques. This strategy can be extended to several other 2D materials systems and open the pathway toward better optoelectronic and nanoelectromechanical systems.
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