1,995 research outputs found

    Two HSCT Mach 1.7 low sonic boom designs

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    The objective of this study was to provide low sonic boom concepts, geometry, and analysis to support wind tunnel model designs. Within guidelines provided by NASA, two High Speed Civil Transport (HSCT) configurations were defined with reduced sonic boom that have low drag, high payload, and good performance. To provide information for assessing the feasibility of reduced sonic boom operation, the two designs were analyzed in terms of their sonic boom characteristics, as well as aerodynamics, weight and balance, and performance characteristics. Low drag and high payload were achieved, but both of the blended arrow-wing configurations have deficiencies in high lift capability, fuel volume, wing loading, balance, and takeoff gross weight. Further refinement of the designs is needed to better determine the commercial viability of low boom operation. To help in assessing low boom design technology, the two configurations were defined as wind tunnel models with altered aft-bodies for the wind tunnel sting mounting system

    Reducing Interconnect Cost in NoC through Serialized Asynchronous Links

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    This work investigates the application of serialization as a means of reducing the number of wires in NoC combined with asynchronous links in order to simplify the clocking of the link. Throughput is reduced but savings in routing area and reduction in power could make this attractiv

    Elliptic aspects of statistical mechanics on spheres

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    Our earlier results on the temperature inversion properties and the ellipticisation of the finite temperature internal energy on odd spheres are extended to orbifold factors of odd spheres and then to other thermodynamic quantities, in particular to the specific heat. The behaviour under modular transformations is facilitated by the introduction of a modular covariant derivative and it is shown that the specific heat on any odd sphere can be expressed in terms of just three functions. It is also shown that the free energy on the circle can be written elliptically.Comment: 22 pages. JyTe

    Identifying high-mobility tetracene derivatives using a non-adiabatic molecular dynamics approach

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    The search for conductive soft matter materials with significant charge mobility under ambient conditions has been a major priority in organic electronics (OE) research. Alkylated tetracenes are promising cost-effective candidate molecules that can be synthesized using wet chemistry methods, resulting in columnar single crystals with pronounced structural stability at and above room temperature. A remarkable characteristic of these materials is the capability of tuning the tetracene core intracolumnar stacking pattern and the crystal melting point via the side chain length and type modifications. In this study, we examine the performance of a series of alkylated tetracenes as hole conducting materials using a novel atomistic simulation technique that allows us to predict both the charge transport mechanism and mobilities. Our simulations demonstrate that molecular wires of alkylated tetracenes are capable of polaronic hole conduction at room temperature, with mobility values ranging up to 21 cm2 V−1 s−1, thus rendering such materials a highly promising choice for flexible OE applications. As regards the charge transfer robustness, two promising tetracene derivatives are identified with the capability of seamless inter-wire polaron delocalization, alleviating possible transfer bottlenecks due to local molecular defects. Our findings suggest that alkylated tetracenes offer an attractive route towards flexible columnar OE materials with unprecedented hole mobilitie

    Viral load, clinical disease severity and cellular immune responses in primary varicella zoster virus infection in Sri Lanka

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    Background In Sri Lanka, varicella zoster virus (VZV) is typically acquired during adulthood with significant associated disease morbidity and mortality. T cells are believed to be important in the control of VZV replication and in the prevention of reactivation. The relationship between viral load, disease severity and cellular immune responses in primary VZV infection has not been well studied. Methodology We used IFNγ ELISpot assays and MHC class II tetramers based on VZV gE and IE63 epitopes, together with quantitative real time PCR assays to compare the frequency and phenotype of specific T cells with virological and clinical outcomes in 34 adult Sri Lankan individuals with primary VZV infection. Principal Findings Viral loads were found to be significantly higher in patients with moderate to severe infection compared to those with mild infection (p<0.001) and were significantly higher in those over 25 years of age (P<0.01). A significant inverse correlation was seen between the viral loads and the ex vivo IFNγ ELISpot responses of patients (P<0.001, r = −0.85). VZV-specific CD4+ T cells expressed markers of intermediate differentiation and activation. Conclusions Overall, these data show that increased clinical severity in Sri Lankan adults with primary VZV infection associates with higher viral load and reduced viral specific T cell responses

    Reducing Interconnect Cost in NoC through Serialized Asynchronous Links

    Full text link
    This work investigates the application of serialization as a means of reducing the number of wires in NoC combined with asynchronous links in order to simplify the clocking of the link. Throughput is reduced but savings in routing area and reduction in power could make this attractiv

    Sensitization of tumour cells to lysis by virus-specific CTL using antibody-targeted MHC class I/peptide complexes

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    A number of cell surface molecules with specificity to tumour cells have been identified and monoclonal antibodies (mAb) to some of these antigens have been used for targeting tumour cells in vivo. We have sought to link the powerful effector mechanisms of cytotoxic T-cells with the specificity of mAb, by targeting recombinant HLA class I molecules to tumour cells using an antibody delivery system. Soluble recombinant MHC class I/peptide complexes including HLA-A2.1 refolded around an immunodominant peptide from the HIV gag protein (HLA-A2/gag) were synthesized, and the stability of these complexes at 37°C was confirmed by enzyme-linked immunosorbent assay using a conformation-specific antibody. MHC class I-negative lymphoma cells (Daudi) were labelled with a biotinylated mAb specific for a cell surface protein (anti-CD20) then linked to soluble biotinylated HLA-A2/gag complexes using an avidin bridge. Flow cytometry revealed strong labelling of lymphoma cells with HLA-A2/gag complexes (80-fold increase in mean channel fluorescence). CTL specific for HLA-A2/gag efficiently lysed complex-targeted cells, while control CTL (specific for an HLA-A2.1-restricted epitope of melan-A) did not. Similarly, SK-mel-29 melanoma cells were also efficiently lysed by HLA-A2/gag-specific CTL when HLA-A2/gag complexes were linked to their surface via the HMW-MAA specific anti-melanoma antibody 225.28s. With further consideration to the in vivo stability of the MHC class I/peptide complexes, this system could prove a new strategy for the immunological therapy of cancer. © 2000 Cancer Research Campaig

    Life cycle analysis of the embodied carbon emissions from 14 wind turbines with rated powers between 50Kw and 3.4Mw

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    In order to facilitate increased renewable energy production, there continues to be a global increase in wind turbine installation. When quantifying the carbon offsets from these installations, the production emissions are rarely accounted for. This paper reports on the embodied carbon emissions from the production of 14 wind turbines, rated between 50 kW and 3.4 MW. The embodied emissions were quantified from emission factors specific to each material involved in manufacture, transport to site, and installation of the turbines. The resulting trend was that higher-rated turbines had greater embodied carbon emissions with one 3 MW turbine incorporating 1046 tCO2eq compared to only 58 tCO2eq for an 80 kW turbine. However, the greater electricity output of the turbines offset these emissions more quickly with a recovery in 64 days for a 3.4 MW turbine compared to 354 days for a 100 kW one. This also resulted in lower carbon emissions per kilowatt hour of electricity generated and quicker payback as a percentage of lifetime of 0.9% for a 3.4 MW turbine compared to 4.3% and 4.9% for a 50 and 100 kW turbines, respectively. The findings of this analysis indicate that a preference for installation of higher-rated, over lower-rated, turbines should be favoured for greater environmental benefits
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