3,957 research outputs found

    Garuda 5 (khyung lnga): Ecologies of Potency and the Poison-Medicine Spectrum of Sowa Rigpa’s Renowned ‘Black Aconite’ Formula

    Get PDF
    This article focuses on ethnographic work conducted at the Men-Tsee-Khang (Dharamsala, India) on Garuda 5 (khyung lnga), a commonly prescribed Tibetan medical formula. This medicine’s efficacy as a painkiller and activity against infection and inflammation is largely due to a particularly powerful plant, known as ‘virulent poison’ (btsan dug) as well as ‘the great medicine’ (sman chen), and identified as a subset of Aconitum species. Its effects, however, are potentially dangerous or even deadly. How can these poisonous plants be used in medicine and, conversely, when does a medicine become a poison? How can ostensibly the same substance be both harmful and helpful? The explanation requires a more nuanced picture than mere dose dependency. Attending to the broader ‘ecologies of potency’ in which these substances are locally enmeshed, in line with Sienna Craig’s Efficacy and the Social Ecologies of Tibetan Medicine (2012), provides fertile ground to better understand the effects of Garuda 5 and how potency is developed and directed in practice. I aim to unpack the spectrum between sman (medicine) and dug (poison) in Sowa Rigpa by elucidating some of the multiple dimensions which determine the activity of Garuda 5 as it is formulated and prescribed in India. I thus embrace the full spectrum of potency— the ‘good’ and the ‘bad,’ the ‘wanted’ and the ‘unwanted’—without presuming the universal validity of biomedical notions of toxicity and side effects

    Introduction | Approaching Potent Substances in Medicine and Ritual across Asia

    Get PDF
    Introduction to themed research articles on Approaching Potent Substances in Medicine and Ritual across Asia

    Reduction of nitrogen oxides by injection of urea in the freeboard of a pilot scale fluidized bed combustor

    Get PDF
    The ‘thermal deNOx’ process using urea has been investigated in a 1 MW fluidized bed combustor. NOx reductions of up to 76% were obtainable by using this method. The experimental results show that urea is at least as active as NH3, which is commonly used in this application, but which is far more toxic and corrosive. Emission levels of 200 mg m−3 for NOx could be achieved by injecting the urea at a height of 2 m above the distribution plate in a molar ratio urea:NOx = 1.5. The SO2 emission value also appeared to be reduced when the urea was injected at a urea: NOx molar ratio > 4

    Symplectic integration of space debris motion considering several Earth's shadowing models

    Full text link
    In this work, we present a symplectic integration scheme to numerically compute space debris motion. Such an integrator is particularly suitable to obtain reliable trajectories of objects lying on high orbits, especially geostationary ones. Indeed, it has already been demonstrated that such objects could stay there for hundreds of years. Our model takes into account the Earth's gravitational potential, luni-solar and planetary gravitational perturbations and direct solar radiation pressure. Based on the analysis of the energy conservation and on a comparison with a high order non-symplectic integrator, we show that our algorithm allows us to use large time steps and keep accurate results. We also propose an innovative method to model Earth's shadow crossings by means of a smooth shadow function. In the particular framework of symplectic integration, such a function needs to be included analytically in the equations of motion in order to prevent numerical drifts of the energy. For the sake of completeness, both cylindrical shadows and penumbra transitions models are considered. We show that both models are not equivalent and that big discrepancies actually appear between associated orbits, especially for high area-to-mass ratios

    NIMASTEP: a software to modelize, study and analyze the dynamics of various small objects orbiting specific bodies

    Full text link
    NIMASTEP is a dedicated numerical software developed by us, which allows one to integrate the osculating motion (using cartesian coordinates) in a Newtonian approach of an object considered as a point-mass orbiting a homogeneous central body that rotates with a constant rate around its axis of smallest inertia. The code can be applied to objects such as particles, artificial or natural satellites or space debris. The central body can be either any terrestrial planet of the solar system, any dwarf-planet, or even an asteroid. In addition, very many perturbations can be taken into account, such as the combined third-body attraction of the Sun, the Moon, or the planets, the direct solar radiation pressure (with the central body shadow), the non-homogeneous gravitational field caused by the non-sphericity of the central body, and even some thrust forces. The simulations were performed using different integration algorithms. Two additional tools were integrated in the software package; the indicator of chaos MEGNO and the frequency analysis NAFF. NIMASTEP is designed in a flexible modular style and allows one to (de)select very many options without compromising the performance. It also allows one to easily add other possibilities of use. The code has been validated through several tests such as comparisons with numerical integrations made with other softwares or with semi-analytical and analytical studies. The various possibilities of NIMASTEP are described and explained and some tests of astrophysical interest are presented. At present, the code is proprietary but it will be released for use by the community in the near future. Information for contacting its authors and (in the near future) for obtaining the software are available on the web site http://www.fundp.ac.be/en/research/projects/page_view/10278201/Comment: Astronomy & Astrophysics - Received: 25 November 2011 / Accepted: 27 February 2012 -- 14 pages, 4 figure

    Zonation, Competitive Displacement and Standing Crop of Northwest Iowa Fen Communities

    Get PDF
    Well developed Iowa fens contain three distinct vegetation zones (border zone, sedge mat zone and discharge zone). On the average, the above ground standing crop of these zones is 425, 197 and 528 g/m2 respectively. Species growing on these fens show three basic distributional patterns: (1) they grow in the border and discharge zones; (2) they grow primarily in the sedge mat zone or (3) they grow in all three zones. Individual plants of species growing in the border and/or discharge zone are on the average 1.6 to 2.7 times taller and weigh 1.8 to 5.4 times more than when they grow on the sedge mat zone. Species with primarily bimodal or ubiquitous distributions show the greatest decline in height and weight when found in the discharge zone. The three Iowa fen zones are a result of differences in environmental conditions, plus competitive displacement of the dominant sedge mat species from the border and discharge zones
    • …
    corecore