1,637 research outputs found

    ESTIMATING REGIONAL ENERGY AND NATURAL RESOURCE FLOWS

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    Estimates of direct and indirect material and energy usage for New York State are derived from existing input-output and natural resource and energy databases. The work provides both a generally applicable methodology and an empirical example for estimating energy and material flow impacts at the regional level.Resource /Energy Economics and Policy,

    The flow of a Newtonian liquid on rotating inclined surfaces with application to atomization

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    Spinning cup atomizers are used industrially to produce an airborne spray. Often the size distribution of the spray is important. The size distribution of the spray depends on the physical dimensions of the cup, the operating-conditions and the physical properties of the fluid to be atomized. A spinning cup atomizer can be considered in the following way. The liquid to be atomized is fed centrally on to the surface of the cup where it begins to thin into a liquid film under the centrifugal action of the rotating cup. As the liquid flows film-wise to the lip of the cup, where atomization occurs, it obtains energy from the cup. Obviously, efficient atomization will occur if the liquid reaches the lip of the cup after it has picked up sufficient energy and if it was evenly distributed on the cup initially. [Continues.

    Quantum limit in resonant vacuum tunneling transducers

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    We propose an electromechanical transducer based on a resonant-tunneling configuration that, with respect to the standard tunneling transducers, allows larger tunneling currents while using the same bias voltage. The increased current leads to an increase of the shot noise and an increase of the momentum noise which determine the quantum limit in the system under monitoring. Experiments with micromachined masses at 4.2 K could show dominance of the momentum noise over the Brownian noise, allowing observation of the quantum-mechanical noise at the mesoscopic scale

    Unblocking high-value botanical value chains: Is there a role for blockchain systems?

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    Blockchain systems are a fast emerging and a currently widely discussed novel strategy for a decentralised cryptographically-enhanced digital ledger recording transactions among stakeholders. This perspective paper looks at its potential uses in the context of high value and mostly low volume botanical material traded globally and used as medicines, health foods, in cosmetics and other applications. We offer a perspective on key areas in the supply of such products globally and how blockchain systems may help in sustainable sourcing, quality assurance, and in tackling supply problems in cases of complex multiherbal preparations. Both open and closed blockchain systems are feasible, and it seems likely that, at least in the initial development, closed ones are the main ones to be utilized. While blockchain’s potential is not yet clear, the examples presented here highlight the opportunities of this new technology

    St John’s wort (Hypericum perforatum) products – an assessment of their authenticity and quality

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    St John’s wort products (Hypericum perforatum L.) are widely available for sale in many countries including the UK via the internet. In the UK, these products are required to hold either a marketing authorisation or Traditional herbal registration (THR) to be sold legally. The THR and other regulatory schemes help to ensure product safety and quality providing an example of best practice but there is a risk if both regulated and un-regulated products continue to be available to consumers. Aims: the project is embedded in a larger study aiming to investigate the quality of different herbal medicinal products along diverse value chains. Here we focus on a comparison of the quality of the finished products and assess phytochemical variation between registered products (THRs) and products obtained from the market without any registration. Methods: 47 commercial products (granulated powders and extracts) were sourced from different suppliers. We analysed these samples using high performance thin layer chromatography (HPTLC) and 1H-NMR spectroscopy coupled with multi-variate analysis software following a method previously developed by our group. Results: the consistency of the products varies significantly. Adulteration of the products (36%), possibly with other Hypericum species obtained from China or use of chemically distinct H. perforatum cultivars or chemotypes, and adulteration of the products (19%) with food dyes (tartrazine, amaranth, brilliant blue, sunset yellow) were the principle findings of this study. Conclusions: There is significant compositional variation among commercial finished products and two main causative quality problems were identified as adulteration by incorrect species or adulteration with food dyes. Generally, food supplements and unlicensed products were found to be of poorer quality than the regulated ones like registered THRs

    Chrysanthemum species used as food and medicine: Understanding quality differences on the global market

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    Background Chrysanthemum flowers [Ch. x morifolium (Ramat.) Hemsl. and Ch. indicum L.] are a globally used and pharmacologically interesting botanical drug, however, with variable product quality. Objective We aim at understanding the chemical variability of primary material available commercially based on different origins and associated quality problems like contamination with heavy metals. This needs to be assessed in the context of the current regulations for this botanical drug and associated problems. Material and Methods 15 C. indicum L. and 50 C. x morifolium (Ramat.) Hemsl., including a range of geographical cultivars recognized in China, samples from the USA, Europe and China were analyzed using High Performance Thin Layer Chromatography (HPTLC) to compare their general chemical profile. Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) was used to quantify heavy metal contamination. Results The: HPTLC fingerprints of C. indicum samples are clearly distinguishable from C. x morifolium. Fingerprints of samples from the same cultivars collected from markets in different countries (USA and China) show different patterns. Large variance of fingerprints within each cultivar group was observed. The heavy metal analysis showed excessive amounts of some harmful heavy metal in some commercial products with excessive cadmium being the most frequent problem. Conclusions The Chinese medicinal cultivars vary. Differences between samples sourced from the USA and China might be ascribable to geographical factors (e.g. soil composition), degradation during transport/storage or adulteration, but geographical differences should also be taken into account. Importantly, a much more detailed definition of the drug are needed for better quality control. In addition, with continuous contamination problem observed, a more widespread regulation is an essential requirement for better quality

    SPHERICAL VS CYLINDRICAL ENGINE BEARINGS

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    ABSTRACT Spherical bearings have been used successfully in engines for some years. The spherical bearing geometry allows a simplified axisymmetric piston design; gradual rotation of the piston and rings results in axisymmetric sidewall wear, temperature distribution and thermal expansion. A previouslydescribed concept engine design incorporating a spherical joint piston was based on an existing production engine with a conventional cylindrical piston pin. Previously-developed finite element lubrication analysis methods are applied to both designs and predictive comparisons made. INTRODUCTION Spherical bearings have been used successfully in engines for some years. The large (400 mm bore) Sulzer Z40 series medium speed 4-stroke Diesel engine has a spherical piston bearing which has been well-documented by its maker The spherical bearing design allows a simplified axisymmetric piston design; gradual rotation of the piston and rings results in axisymmetric sidewall wear, temperature distribution and thermal expansion. Development of a low heat rejection Diesel engine sponsored by the Department of Energy (DOE) and monitored by NASA-Lewis began at Cummins Engine Company in 1989 and ended around 1995 [3-8]. The LE-55 (Low Emission, 55% thermal efficiency) concept engine design incorporating a spherical joint piston was based on an existing Cummins L10 production engine with a conventional cylindrical piston pin. The Cummins L10 was a 10 liter 6 cylinder in-line Diesel engine produced for 15 years ending around 1998. The SCE (Single-Cylinder Engine) L10 version used for test purposes formed the basis for successful life tests of LE-55 hardware

    Dynamics of offset bearings: parametric studies

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    Novel "offset" designs offer greatly improved durability in applications fo

    Medicinal plants from the Himalayan region as potential novel antimicrobial and anti-inflammatory skin treatments

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    Background and Objectives: Adequate treatment of wounds remains one of the major medical needs globally, most notably in the regions with poor or limited access to health care. In many local and traditional systems of medicine, plants are often widely used for treating infected wounds. / Aim and objectives: The overarching aim of this project was selection of potential species for use in a future treatment by combining with plant resources with aspects of antimicrobial photodynamic therapy (aPDT). Specifically, we focussed on species used locally in the Himalayan region for the treatment of skin disorders and then assessed the existing pharmacological evidence for key species based on the published evidence available. / Methods: Database searches were performed to identify relevant publications describing local and traditional uses of plants in the Himalayan region of Bhutan, PR China, India, Nepal and Pakistan. Using the Global Biodiversity Information Facility (GBIF), species were researched in terms of their distribution including in different climatic regions, focussing on species mostly found in higher climatic zones (based on the Köppen–Geiger climate classification). For species used in three or more countries and restricted to the higher altitudes, data on safety, pharmacology, as it relates to dermatological conditions, and phytochemistry were retrieved. / Key findings: The study identified a total of 606 species that are used in the treatment of various skin conditions often associated with infections reported in 84 articles. Common weeds like Ageratum conyzoides and Bidens pilosa, widely used and cultivated species like Centealla asiatiaca and Prunus armenica were excluded. This ultimately led to the identification of a core group of five widely used species restricted to the Himalayan region (Cedrus deodara, Nardostachys jatamansi, Pinus wallichiana, Pinus roxburghii and Valeriana jatamansi). / Conclusions: Here we apply a novel approach comprising an assessment of the published information on the use of medicinal plants (i.e. local and traditional knowledge) in the context of their potential to be used in a biomedical form of clinical treatment – aPDT. Then, once sustainable sourcing based on access and benefit-sharing arrangements is in place, these species are investigated for their potential in wound treatment. Ultimately, the goal is to develop a new baseline for primary health care in some of the regions of the world with poor or limited access to health care
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