4,978 research outputs found

    Wing flutter calculations with the CAP-TSD unsteady transonic small disturbance program

    Get PDF
    The application and assessment is described of CAP-TSD (Computational Aeroelasticity Program - Transonic Small Disturbance) code for flutter prediction. The CAP-TSD program was developed for aeroelastic analysis of complete aircraft configurations and was previously applied to the calculation of steady and unsteady pressures. Flutter calculations are presented for two thin, swept-and-tapered wing planforms with well defined modal properties. The calculations are for Mach numbers from low subsonic to low supersonic values, including the transonic range, and are compared with subsonic linear theory and experimental flutter data. The CAP-TSD flutter results are generally in good agreement with the experimental values and are in good agreement with subsonic linear theory when wing thickness is neglected

    Large-scale Victorian manufacturers: reconstructing the lost 1881 UK employer census

    Get PDF
    We present the first available - and near-complete - list of large UK manufacturers in 1881, by complementing the employer data from that year’s population census (recovered by the British Business Census of Entrepreneurs project) with employment and capital estimates from other sources. The 438 largest firms with 1,000 or more employees accounted for around one-sixth of manufacturing output. Examples can be found in most industries. Exploiting powered machinery, intangible assets, new technologies and venture capital, and generally operating in competitive markets, their exports about equalled domestic sales. The more capital-intensive accessed stock markets, more - and in larger firms - than in follower economies. Some alleged later causes of UK decline relative to the US or Germany cannot be observed in 1881. Indeed, contemporary overseas observers - capitalist and socialist - correctly recognized the distinctive features of UK manufacturing as its exceptional development of quoted corporations, professional managers and “modern,” scalable, factory production

    Environmental economics and valuation: towards a practical investment framework for Catchment Management Authorities in New South Wales

    Get PDF
    The Catchment Management Authorities in New South Wales have programs that are collectively investing $436 million over four years to achieve catchment-wide natural resource/environmental improvements. In this paper, we consider the question of how to best allocate these resources so as to increase the well-being of the public within catchments and the state. We consider the current approaches used by CMAs and make a case for Benefit-Cost Analysis as an alternative means of assessing ex ante questions of priority setting at the catchment level and for project appraisal. A major issue for BCA is the estimation of potential benefits from project investments, particularly the estimation of values that catchment communities and those living outside the catchments place on the non-use benefits associated with environmental improvements. We discuss alternative means of eliciting such values and propose the stated-preference method of Choice Modelling as a means of overcoming this Benefit-Cost Analysis shortcoming, because it incorporates advances in non-market valuation.environmental, economics, choice modelling, non-use values, investment framework, Environmental Economics and Policy,

    The Federal Trademark Dilution Act of 1995: Potent Weapon or Uphill Battle?

    Get PDF
    Following a brief discussion of the history of trademark infringement law, the events leading to the FTDA, and an overview of the FTDA, this paper discusses the major causes of the FTDA\u27s ineffectiveness. We will then review the application of the act, discuss its implications on the future of trademark ownership in business, and suggest improvements to the legal application of the act

    Transparent multi-zone crystal growth furnace and method for controlling the same

    Get PDF
    A crystal growth system, comprising: a furnace; a plurality of heating elements coupled to said furnace, each said plurality of heating elements defining a heat zone, each said heating element set to a desired temperature value; a plurality of thermocouples associated with respective heat zones to detect a temperature value; a translation system for passing an ampoule containing crystal growth material through said furnace into said heat zones and providing a positional location of said ampoule and; a multi-variable self-tuning temperature controller connected to said plurality of heating elements, said plurality of thermocouples and said translation system, said controller monitoring each said zone temperature value and upon considering the thermal interaction of heating zones and the moving thermal inertia of the ampoule, adjusting voltage input to said heat zones to obtain optimal crystal growth within said ampoule

    Evolution of entanglement within classical light states

    Full text link
    We investigate the evolution of quantum correlations over the lifetime of a multi-photon state. Measurements reveal time-dependent oscillations of the entanglement fidelity for photon pairs created by a single semiconductor quantum dot. The oscillations are attributed to the phase acquired in the intermediate, non-degenerate, exciton-photon state and are consistent with simulations. We conclude that emission of photon pairs by a typical quantum dot with finite polarisation splitting is in fact entangled in a time-evolving state, and not classically correlated as previously regarded

    Policy responses to invasive native species: issues of social and private benefits and costs

    Get PDF
    Farm and catchment managers in Australia face decisions about controlling invasive native species (or scrub) which may infest agricultural land. The treatment of this land to remove the infestation and re-establish native pastures is likely to be expensive for landholders. Yet there are potential social benefits from such remediation and so a policy question arises of what to do to about facilitating such change. New South Wales state government legislation addresses this issue through regulations, and the Catchment Management Authorities are responsible for administering public funds to achieve associated natural resource improvements. However, the extent of the private costs and social benefits associated with such changes are not known, which precludes benefit-cost analyses using the traditional welfare economics framework. This paper reports results of a social and private economic analysis of the impacts of a typical infestation remediation decision. We show that for the landholder the private costs exceed the benefits achieved from increased livestock productivity. However, there are social benefits expressed by the willingness to pay by members of the local catchment community for improvements in native vegetation and biodiversity. When these social benefits are included, the economic analysis shows a positive social net benefit. This raises questions of how to reconcile the public and private accounting, and whether any changes to policies, regulations or procedures for natural resource management in New South Wales are warranted.Invasive native scrub, environmental values, choice modelling, financial, economic, Namoi catchment,

    MECHANISMS OF GENETIC RESISTANCE TO FRIEND VIRUS LEUKEMIA IN MICE : I. ROLE OF89Sr-SENSITIVE EFFECTOR CELLS RESPONSIBLE FOR REJECTION OF BONE MARROW ALLOGRAFTS

    Get PDF
    Resistance to malignant erythropoiesis induced by Friend spleen focus-forming virus and resistance to marrow stem cell allografts are under genetic control. Strains of mice, e.g., C57BL/6 and B10.D2, which are homozygous for resistance at the Fv-2 locus, are also good rejectors of most bone marrow allografts. 89Sr, a bone-seeking isotope, irradiates marrow but not other lymphoid organs and abrogates resistance to marrow allografts without suppressing T- or B-cell functions. Thus, marrow-dependent effector cells (M cells) seem to resist allogeneic stem cells. To test if the genetic resistance to Friend virus (FV) is also mediated by M cells, B6 mice were treated with 89Sr using a dosage schedule known to abrogate resistance to allogeneic marrow cells. 9 days after FV infection of such mice, the spleens showed malignant erythroblastosis which could not be suppressed by prior hypertransfusion, a procedure which suppresses physiologic erythropoiesis. Such 89Sr-treated B6 mice also supported extensive virus replication, while control mice did not. FV markedly suppressed the ability of 89Sr-treated B6 mice to produce antisheep red blood cell (SRBC) antibodies, a feature seen normally only in genetically susceptible mice. Thus, 89Sr-treated B6 mice behaved in these respects as if they were susceptible to FV. When increasing doses of 89Sr were administered to B6 mice, a dose-related loss of resistance to FV was seen. Therefore, it appears that 89Sr-sensitive M cells mediate the genetic resistance to FV. The results of experiments with 89Sr indicated that genetically resistant mice would be expected to possess target cells which are susceptible to transformation by FV. To verify this corollary, bone marrow cells from B10.D2 (Fv-2rr) mice were transplanted into previously infected and lethally irradiated DBA/2 (Fv-2ss) recipients which share the same H-2d alleles. 5–15 days later, the spleens of DBA/2 primary recipients yielded transformed cells which were capable of producing splenic tumor colonies upon transplantation into adult, unirradiated B10.D2 secondary recipients. Various control experiments clearly indicated that the tumor colonies so induced were of B10.D2 marrow origin. This indicated that B10.D2 stem cells could be transformed when allowed to interact with FV in the spleens of susceptible DBA/2 mice. However, 30 days after transplantation of B10.D2 bone marrow cells into DBA/2 recipients, no transformed cells were detected. Apparently, in the 30-day interval precursors in the B10.D2 marrow gave rise to mature M cells which resisted the leukemic process. Since M cells recognize hybrid or hemopoietic histocompatability antigens expressed on primitive normal and transformed hematopoietic cells, we suggest that M cells may exert surveillance by rejecting leukemic cells. Thus, marrow transplantation from genetically resistant donors may provide a new mode of treatment for leukemia, by providing precursors of M cells and other immunocompetent cell types

    Parallel-propagating Fluctuations at Proton-kinetic Scales in the Solar Wind are Dominated by Kinetic Instabilities

    Get PDF
    We use magnetic helicity to characterise solar wind fluctuations at proton-kinetic scales from Wind observations. For the first time, we separate the contributions to helicity from fluctuations propagating at angles quasi-parallel and oblique to the local mean magnetic field, B0\mathbf{B}_0. We find that the helicity of quasi-parallel fluctuations is consistent with Alfv\'en-ion cyclotron and fast magnetosonic-whistler modes driven by proton temperature anisotropy instabilities and the presence of a relative drift between α\alpha-particles and protons. We also find that the helicity of oblique fluctuations has little dependence on proton temperature anisotropy and is consistent with fluctuations from the anisotropic turbulent cascade. Our results show that parallel-propagating fluctuations at proton-kinetic scales in the solar wind are dominated by proton temperature anisotropy instabilities and not the turbulent cascade. We also provide evidence that the behaviour of fluctuations at these scales is independent of the origin and macroscopic properties of the solar wind.Comment: Accepted for publication in ApJL. 6 Pages, 3 figures, 1 tabl
    • 

    corecore