2,784 research outputs found

    The use of soil analysis in the interpretation of an early historic landscape at Puxton in Somerset

    Get PDF
    Reproduced with permission of the publisher. Journal home page http://www.landscapestudies.com/index_files/Volumes.htmSoil samples taken from two adjoining fields close to the village of Puxton in the county of North Somerset, UK, were analysed in 1997 for heavy metals, phosphorus, magnetic susceptibility and loss on ignition as part of an archaeological investigation of the origins and development of a medieval settlement. It had been argued that an oval-shaped field next to the church was the nucleus of marshland reclamation during the early medieval period, though it was unclear whether the enclosure was occupied by a settlement or was simply an area of embanked agricultural land. Soil chemistry shows certain elements, including phosphorus and the heavy metals (Pb, Zn, Cd, Cu, etc), to be concentrated in a restricted part of the enclosure, which earthwork, resistivity and fieldwalking surveys suggest correlates with an area of human occupation associated with the dumping of midden material (a hypothesis confirmed through excavation). This paper demonstrates the value of multifaceted soil chemistry, alongside a range of other survey methods, for characterizing the nature of human activity on archaeological sites, and in the future may be used to locate previously unrecorded sites in more speculative landscape surveys

    On a class of linearizable Monge-Amp\`ere equations

    Full text link
    Monge-Amp\`ere equations of the form, uxxuyy−uxy2=F(u,ux,uy)u_{xx}u_{yy}-u_{xy}^2=F(u,u_x,u_y) arise in many areas of fluid and solid mechanics. Here it is shown that in the special case F=uy4f(u,ux/uy)F=u_y^4f(u, u_x/u_y), where ff denotes an arbitrary function, the Monge-Amp\`ere equation can be linearized by using a sequence of Amp\`ere, point, Legendre and rotation transformations. This linearization is a generalization of three examples from finite elasticity, involving plane strain and plane stress deformations of the incompressible perfectly elastic Varga material and also relates to a previous linearization of this equation due to Khabirov [7]

    Poverty Alleviation through Sustainable Strategic Business Models: Essays on Poverty Alleviation as a Business Strategy

    Get PDF
    How can the private sector serve the unmet needs of the world’s poor while, at the same time, attracting new business opportunities and advancing the standard of living of those living in poverty? One approach to this, known as the base-of the-pyramid, is for the private sector to develop towards including the poor as both producers and consumers. In this thesis we focus on some critical questions in base-of-the-pyramid research. In cooperation with NGOs, development organizations and micro finance institutions, we collected a unique dataset of 143 firms operating in base-of-the-pyramid markets in a total of 105 countries. Their focal group of customers, employees, suppliers, and/or distributors have an average daily purchasing power of $2 or less. Building upon this dataset, we develop an empirically derived classification of business challenges for firms at the base-of-the-pyramid, and examine differences with high-income markets. We also extend and test the central postulate that embedding social and environmental value in a firm’s business model drives a firm’s financial performance at the base-of-the-pyramid. Lastly, we build a management support model, which can be used to develop profitable pro-poor business models. We provide managers and entrepreneurs with the questions to ask, the framework to help formulate answers to these questions, and the qualities to search for in the answers. To this end, we clarify and conceptually advance the strategic business model concept, which provides the multi-theoretical approach necessary for disruptive innovation and augments our understanding of competitive advantage

    A Theoretical Inquiry Exploring Archetypal Art Therapy with Adolescent Clientele

    Get PDF
    This research seeks to answer the question: What is archetypal art therapy and how can it be applied in an art therapy context with adolescent clientele? An archetypal approach to art therapy is grounded in the theories of archetypal psychology, a post-Jungian school of thought founded by James Hillman. It approaches questions of psychology through imagination and the image. Three important ideas to practicing archetypal art therapy are the image’s structure and content, an imaginal approach, and metaphorical and poetic language. This research addresses the need for a recent, accessible survey of archetypal art therapy, and discusses how to utilize this approach with adolescent clientele. The findings of this paper can be applied to the creation of a new art therapy framework for working with adolescent clientele which addresses aspects of the soul and an understanding of experience that does not rely on development models or isolated pathologies

    Self-Similarity in Random Collision Processes

    Full text link
    Kinetics of collision processes with linear mixing rules are investigated analytically. The velocity distribution becomes self-similar in the long time limit and the similarity functions have algebraic or stretched exponential tails. The characteristic exponents are roots of transcendental equations and vary continuously with the mixing parameters. In the presence of conservation laws, the velocity distributions become universal.Comment: 4 pages, 4 figure

    Ferromagnetic resonance in periodic particle arrays

    Full text link
    We report measurements of the ferromagnetic resonance (FMR) spectra of arrays of submicron size periodic particle arrays of permalloy produced by electron-beam lithography. In contrast to plane ferromagnetic films, the spectra of the arrays show a number of additional resonance peaks, whose position depends strongly on the orientation of the external magnetic field and the interparticle interaction. Time-dependent micromagnetic simulation of the ac response show that these peaks are associated with coupled exchange and dipolar spin wave modesComment: 4 pages, 4 figure

    Thermalization of an anisotropic granular particle

    Full text link
    We investigate the dynamics of a needle in a two-dimensional bath composed of thermalized point particles. Collisions between the needle and points are inelastic and characterized by a normal restitution coefficient α<1\alpha<1. By using the Enskog-Boltzmann equation, we obtain analytical expressions for the translational and rotational granular temperatures of the needle and show that these are, in general, different from the bath temperature. The translational temperature always exceeds the rotational one, though the difference decreases with increasing moment of inertia. The predictions of the theory are in very good agreement with numerical simulations of the model.Comment: 7 pages, 6 Figures, submitted to PRE. Revised version (Fig1, Fig5 and Fig6 corrected + minor typos

    How to Determine the Increasing Returns Sensitivity of Your Industry?

    Get PDF
    Increasing returns means that self-reinforcing mechanisms are at work within firms and markets. These mechanisms come in four forms: scale effects, learning effects, network effects and social interaction effects. Some industries are more sensitive to increasing returns than others. It is important that managers are able to assess the increasing returns sensitivity of their industry. Therefore we have developed an analytical tool that allows managers to assess their industry’s sensitivity to increasing returns. Four case studies are used to illustrate this typology. The analytic tool shows that an industry has high increasing returns sensitivity if a combination of the following situations exists: 1) high fixed costs and low, or even zero, variable costs, indicating a high sensitivity to scale effects, 2) a high level of complexity of the business process and/or the products, indicating a high sensitivity to learning effects, 3) low product utility and high network utility, indicating a high sensitivity to network effects and finally, 4) a high degree of social involvement by customers and potential customers, indicating a high sensitivity to social interaction effects

    Citrate and malonate increase microbial activity and alter microbial community composition in uncontaminated and diesel-contaminated soil microcosms

    Get PDF
    Petroleum hydrocarbons (PHCs) are among the most prevalent sources of environmental contamination. It has been hypothesized that plant root exudation of low molecular weight organic acid anions (carboxylates) may aid degradation of PHCs by stimulating heterotrophic microbial activity. To test their potential implication for bioremediation, we applied two commonly exuded carboxylates (citrate and malonate) to uncontaminated and diesel-contaminated microcosms (10 000 mg kg−1; aged 40 days) and determined their impact on the microbial community and PHC degradation. Every 48 h for 18 days, soil received 5 µmol g−1 of (i) citrate, (ii) malonate, (iii) citrate + malonate or (iv) water. Microbial activity was measured daily as the flux of CO2. After 18 days, changes in the microbial community were assessed by a community-level physiological profile (CLPP) and 16S rRNA bacterial community profiles determined by denaturing gradient gel electrophoresis (DGGE). Saturated PHCs remaining in the soil were assessed by gas chromatography–mass spectrometry (GC-MS). Cumulative soil respiration increased 4- to 6-fold with the addition of carboxylates, while diesel contamination resulted in a small, but similar, increase across all carboxylate treatments. The addition of carboxylates resulted in distinct changes to the microbial community in both contaminated and uncontaminated soils but only a small increase in the biodegradation of saturated PHCs as measured by the n-C17 : pristane biomarker. We conclude that while the addition of citrate and malonate had little direct effect on the biodegradation of saturated hydrocarbons present in diesel, their effect on the microbial community leads us to suggest further studies using a variety of soils and organic acids, and linked to in situ studies of plants, to investigate the role of carboxylates in microbial community dynamics
    • …
    corecore