507 research outputs found

    Better to Give Than to Receive: Evaluating Recent IP Donation Tax Policy Changes

    Get PDF
    Over the past decade, charitable contributions of intellectual property have grown rapidly. This growth has coincided with tremendous abuse as firms have sought inflated valuations of donated intellectual property in order to claim larger tax deductions. In 2004, Congress responded by passing section 882 of the American Jobs Creation Act, which drastically changed the rules governing donations of intellectual property. This iBrief argues that Congress, in addressing overvalued intellectual property donations, went too far in its efforts by failing to fully consider the importance of positive donor incentives. After discussing other proposed policies, this iBrief suggests a hybrid policy that combines strong donor incentives with protective measures against overvaluation

    Sellars, Scientific Realism, and the Philosophy of Mind

    Get PDF
    My thesis is an analysis and application of Wilfrid Sellars’ philosophy of science. Twenty years after his death, his philosophical significance remains only partly understood. This is acutely true in the philosophy of mind, where Sellars’ proposals have directly shaped the contemporary problem space. I will show how the competing views of Paul Churchland, Daniel Dennett, and Jerry Fodor all find their conceptual and historical roots in Sellars’ work. Sellars is the source and watershed for their various conceptions of mind in the world. First, they all share a commitment to scientific realism (SR). The ways that the doctrine of SR impacts the philosophy of mind were first explored by Sellars in his famous Empiricism and the Philosophy of Mind (1956). In chapter one, I give a detailed account of SR and examine some empiricist alternatives to that view. I argue that Sellars’ view of science and theoretical explanation provides a comprehensive defense of SR’s central commitments. In chapter two, I highlight two important methodological claims inherited from Sellars. The first is that that the mind-body problem is “the problem of formulating a philosophically adequate account of the various mental phenomena within the context of the ontology provided by theoretical science.” (Loux, 1977) The second claim is that our knowledge of mind is theoretical knowledge. This groundbreaking claim stands in stark contrast to the Cartesian legacy which takes our knowledge of mind as immediate and incorrigible. In chapter three, I employ Sellars’ framework to analyze contemporary philosophy of mind. The methodological commitments of Sellars’ SR provide a rich philosophical model for evaluating various theories of mind. This conceptual apparatus casts into sharp relief the extent to which Churchland’s eliminative materialism, Dennett’s inter- pretivism, and Fodor’s intentional realism each betray and embody Sellars’ fundamental proposals

    Multiple Quantum Well Structures As Optical Waveguides

    Get PDF
    This thesis is concerned with the design, fabrication and characterisation of semiconductor optical waveguides in which the high index guiding layer is a multiple quantum well structure (MQWS), consisting of alternate layers of high and low band gap semiconductors with the electrons and holes in the MQWS being confined to the low band gap material. This confinement in two dimensions alters greatly the electronic and optical properties of the MQWS in comparison to the bulk properties of the constituent layers. The basic concepts involved in MQW waveguides are introduced using an elementary quantum mechanical analysis of quantum wells together with a brief description of the properties of dielectric waveguides, A more detailed treatment of the electronic and optical properties of MQWS and a review of published experimental work is used to show that the fundamental absorption edge is much more abrupt than that in the corresponding bulk material with strong excitonic characteristics being evident even at room temperature. In addition, the absorption edge is seen to be anisotropic with the fundamental energy gap being larger for light polarised perpendicular to the MQW layers. This anisotropic absorption edge, together with the layered dielectric nature of MQWS, makes them birefringent with a smaller refractive index for light polarised perpendicular to the MQW layers. The quantum confinement of carriers in MQWS also enhances their electroabsorption and electro-optic properties through the quantum confined Stark effect. Standard techniques used in the design, fabrication and analysis of bulk semiconductor waveguides are developed for application to MQW waveguides. These include analytical and numerical techniques for the design of dielectric waveguides; dry etching and metallisation processes for the fabrication of devices; and a laser/optics system to analyse the waveguide devices. To verify these techniques they are first applied to the well-understood case of n/n+ GaAs waveguides and are used to successfully fabricate and analyse single-mode, passive, rib waveguides at l=1.15mum. The electro-optic coefficient is also measured in an active, planar n/n+ waveguide and found to be close to that reported by other workers. The design techniques are then applied to MOWS waveguides resulting in the design of a MQW double heterostructure (MQW-DH), p-i-n diode which was predicted to produce the required Quantum properties (strong, room temperature, excitonic behaviour), waveguide properties (single-mode propagation up to the fundamental absorption edge) and electronic properties (a high reverse bias breakdown voltage and uniform applied electric field). Most of the theoretical work and all the experimental work included is devoted to MQWS in the (Al,Ga)As, III-V semiconductor alloy system. Accordingly, the methods available for growing MQWS in this system are reviewed with Molecular Beam Epitaxy (MBE) being found the most likely method to satisfactorily reproduce the desired structure. MQW-DH were grown at two establishments and are initially studied by photoluminescence and scanning electron microscopy before their planar optical waveguide characteristics are checked using the laser system. Only one sample is found to satisfy all the design requirements, and then only partially. Detailed analysis of the properties of MQW waveguides is therefore limited to this structure. Passive MQW-DH waveguides are demonstrated to exhibit an anisotropic absorption edge as predicted, and it is shown that the design and fabrication techniques developed can be successfully used to obtain single, double and multi-mode strip loaded waveguides. Single-mode waveguides are also used to fabricate passive directional couplers with coupling lengths in good agreement with theoretically predicted values. A semi-empirical model is put forward to describe the band edge electro-absorption of MQWS. Although simple, the model is in qualitative and approximate quantitative agreement with published results. (Abstract shortened by ProQuest.)

    Using earth observation and ground-based data to improve modelled CO2 and CH4 fluxes from peatlands

    Get PDF
    Peatlands are an important store of carbon; they contain ~15-30% of the world’s soil C while covering only ~3% of the land area. They are also the largest natural source of methane (CH4), but the global estimate is highly uncertain. Here, this issue is addressed by developing a combined data - modelling framework to provide optimal estimates of CO2 and CH4 fluxes from an upland UK peat site. An Observing Systems Simulation Experiment (OSSE), using a Bayesian inversion method, is implemented to investigate the CH4, NEP and soil moisture observation temporal frequency and uncertainty required to accurately constrain model parameters and to estimate model predictive uncertainty. The OSSE is used to examine the impact of parameter correlations, bias in low-resolution observations, and unknown model error. The highly model-sensitive parameters are constrained by almost all observations, with a corresponding improvement in model predictive uncertainty. However there is high degree of model equifinality. Biased observations and unaccounted-for model error can result in false confidence in inaccurate model predictions. The OSSE results demonstrate the importance of performing a synthetic experiment prior to using actual data. Finally, real data are used to calibrate the model, which is then used to determine the net CO2 and CH4 flux for the site. The results highlight a possible source of error in the model. It is suggested this is because of an inaccurate representation of the coupling between CO2 and CH4, due to an unaccounted for lag in the methanotrophic activity. This has significant implications for CH4 flux modelling, as many models use a similar formulation for CH4 dynamics. Results are compared with satellite and ground-based measurement characteristics and recommendations are made for the observation and modelling of ecosystems at small spatial scales. This information is useful for modellers, space agencies and field biologists

    A documentary edition of Alexander Craig's 'Pilgrime and Hermite,' 1631: print and manuscript culture across the Union of Crowns

    Get PDF
    This thesis presents the materials for a documentary edition of Alexander Craig’s ‘The Pilgrim and Hermite,’ the facsimiles of the manuscript, a diplomatic transcription of the manuscript & a transcription of the printed witness. These texts are found in Edward Raban’s 1631 print of Craig’s The Pilgrime and Heremite, in forme of a dialogue, and NLS Adv. MS 35.4.14 or The Thoirs Family Commonplace Book. This thesis presents the first available transcription from the manuscript and facilitates the comparison of both texts. The first objective of this project was to make the manuscript text available for further study. Prior to the text itself is an apparatus including a description of both the print and manuscript witnesses and a linguistic description of the manuscript, the data of which is available in the appendix. Secondly, the discussion of the text is evidenced in and commented upon by the culture surrounding the print and manuscript. I have provided the context of each witness and have begun work to document the transmission of the text, the findings of which will necessarily form a separate study. The project is a proof of concept for future work on Craig and editorial studies. Where the sixteen hundreds or, as Priscilla Bawcutt describes it, ‘the neglected seventeenth century’, in Scotland has been charged with detracting from the mastery of the Makars, it is now proving to be a critical area in forming narratives of literature in Scotland. Bringing texts from this period into contemporary literary theory, historical materialist approaches are proving fruitful and encouraging discoveries of networks of literary interests and practice, evidencing experimental and versatile uses of text. These literary pluralities are paralleled in the textual pluralities of the manuscript and print culture of Scotland. Through the further study of manuscript miscellanies, commonplace books, and anthologies, we are starting to form a picture of how texts were used and transmitted, and how they functioned and were understood

    Evaluating The Effect Of Alternative Carbon Allocation Schemes In A Land Surface Model (Clm4.5) On Carbon Fluxes, Pools And Turnover In Temperate Forests

    Get PDF
    How carbon (C) is allocated to different plant tissues (leaves, stem and roots) determines C residence time and thus remains a central challenge for understanding the global C cycle. We used a diverse set of observations (AmeriFlux eddy covariance tower observations, biomass estimates from tree-ring data, and Leaf Area Index (LAI) measurements) to compare C fluxes, pools, and LAI data with those predicted by a Land Surface Model (LSM), the Community Land Model (CLM4.5). We ran CLM for nine temperate (including evergreen and deciduous) forests in North America between 1980 and 2013 using four different C allocation schemes: i) Dynamic C allocation scheme (named D-CLM ) with one dynamic allometric parameter, which allocates C to the stem and leaves to vary in time as a function of annual Net Primary Production (NPP). ii) An alternative dynamic C allocation scheme (named D-Litton ), where, similar to (i) C allocation is a dynamic function of annual NPP, but unlike (i) includes two dynamic allometric parameters involving allocation to leaves, stem and coarse roots iii–iv) Two fixed C allocation schemes, one representative of observations in evergreen (named F-Evergreen ) and the other of observations in deciduous forests (named F-Deciduous ). D-CLM generally overestimated Gross Primary Production (GPP) and ecosystem respiration, and underestimated Net Ecosystem Exchange (NEE). In D-CLM, initial aboveground biomass in 1980 was largely overestimated (between 10527 and 12897 g Cm-2) for deciduous forests, whereas aboveground biomass accumulation through time (between 1980 and 2011) was highly underestimated (between 1222 and 7557 g Cm-2) for both evergreen and deciduous sites due to a lower stem turnover rate in the sites than the one used in the model. D-CLM overestimated LAI in both evergreen and deciduous sites because the leaf C-LAI relationship in the model did not match the observed leaf C-LAI relationship at our sites. Although the four C allocation schemes gave similar results for aggregated C fluxes, they translated to important differences in long-term aboveground biomass accumulation and aboveground NPP. For deciduous forests, D-Litton gave more realistic Cstem/Cleaf ratios and strongly reduced the overestimation of initial aboveground biomass, and aboveground NPP for deciduous forests by D-CLM. We identified key structural and parameterization deficits that need refinement to improve the accuracy of LSMs in the near future. That could be done by addressing some of the current model assumptions about C allocation and the associated parameter uncertainty. Our results highlight the importance of using aboveground biomass data to evaluate and constrain the C allocation scheme in the model, and in particular, the sensitivity to the stem turnover rate. Revising these will be critical to improving long-term C processes in LSMs, and improve their projections of biomass accumulation in forests

    Art and Symbolism: The Technique of Applying Hidden Meaning and Communicating Specific Ideas Through Art

    Get PDF
    Symbolism is an artistic style frequently used in the arts. Through the course of art history, it was its own artistic movement as well. The incorporation of specific symbols, shapes, colors, or identifiable images communicates to the viewer an intended message or statement. Frequently, symbolism appears to be hidden or initially unperceived by the intended audience. In some works, symbolism is so abstract that it needs explanation or clarification to be understood completely by the viewer. This thesis will analyze a few techniques of symbolism that can be incorporated in a work of art to communicate truth, entice thought, point the viewer to a particular concept, or draw out an intended emotion
    • 

    corecore