15,454 research outputs found

    Precision testing the Standard Model

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    Internal consistency of the most sensitive electroweak measurements within the standard model framework is examined. Confirming an earlier observation on the separation of Z-pole asymmetry measurements into {\em hadronisation- free}and {\em hadronisation-sensitive}, the electroweak mixing angle derived using the former is in perfect agreement with the precision W mass. These two complimentary measurements of weak radiative corrections, when combined with the lower limit on Higgs mass, are incompatible with the measured top quark mass. To overcome this inconsistency, a scenario readily testable in Run-II at Tevatron is envisaged: an upward shift of the top quark mass by about 10 GeV (∼2σ\sim 2\sigma). If, however, the improved top quark mass remains at its current value or the lower limit on Higgs mass moves up substantially, then abandoning the SM may become inevitable.Comment: 7 pages, 4 figure

    Recycling and the Environment: a Comparative Review Between Mineral-based Plastics and Bioplastics

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    Since their conception in the 1950s, mineral-based plastics have completely revolutionised our society with production reaching record highs year upon year. This cheap, and durable material has seen usage across a plethora of diverse industries and products, replacing traditional materials such as metals and wood. However, our reliance on mineral-based plastics has led to their improper disposal across the global, affecting our environments and ecosystems. As a response, different methods have been developed to help dispose of the large amounts of plastic waste produced, such as incineration or dumping in landfill sites, but these methods are not without their drawbacks including release of toxic substances into the air and leachate into the soil and waters respectively. Consequently, much interest is generated and channelled in recent years to the introduction of several types of biopolymers. These include plastics based on cellulosic esters, starch derivatives, polyhydroxybutyrate and polylactic acid. These biopolymers have been viewed as a suitable replacement for mineral-based plastics, and their production a good strategy towards sustainable development as they are mainly composed of biocompounds such as starch, cellulose and sugars. This short review article provides an overview as to whether biopolymers can rival mineral-based plastics considering properties such as mechanical strength, Young’s modulus and crystallinity and could they be regarded as a suitable material to reduce our reliance on mineral-based plastics, whilst simultaneously reducing non-renewable energy consumption and carbon dioxide emissions

    [re]locate (binaural mix): Racism and the Sonic Representation of Stephen Lawrence's Story

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    [re]locate revisits the tragic real-life story of the racist murder of Stephen Lawrence near a bus stop in southeast London in 1993. In its original form - a darkened space, approx. 5 x 8 metres in dimension - the six-speaker sound installation exploits the unique qualities of immersive or spatialised audio to place the audience at the centre of events. On entering the darkened installation space, members of the audience take on the role of ‘pedestrians’ or ‘passers-by’ and encounter a reconstruction of events from different perspectives. The experimental audio mix, presented at the conference, is a binaural representation of the immersive multi-channel audio installation for listening with headphones

    Asymmetry measurements at LEP/SLC revisited

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    We examine the fermion asymmetry measurements at LEP and SLC leading to effective weak mixing angle, sin2.theta.eff. We notice very interesting regularity in these measurements. All asymmetry measurements fall in two classes. Class A measurements where hadronisation effects are not relevant for the final result and class B measurements where hadronisation effects can not be avoided and can only be corrected with whatever understanding of these phenomena we have. In each of these classes there is excellent agreement between LEP and SLC results. However the two classes are distinctly apart by more than 3.sigma.. We suggest that for precision test of the standard model the class A measurements should be preferred

    Air pollution and livestock production

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    The air in a livestock farming environment contains high concentrations of dust particles and gaseous pollutants. The total inhalable dust can enter the nose and mouth during normal breathing and the thoracic dust can reach into the lungs. However, it is the respirable dust particles that can penetrate further into the gas-exchange region, making it the most hazardous dust component. Prolonged exposure to high concentrations of dust particles can lead to respiratory health issues for both livestock and farming staff. Ammonia, an example of a gaseous pollutant, is derived from the decomposition of nitrous compounds. Increased exposure to ammonia may also have an effect on the health of humans and livestock. There are a number of technologies available to ensure exposure to these pollutants is minimised. Through proactive means, (the optimal design and management of livestock buildings) air quality can be improved to reduce the likelihood of risks associated with sub-optimal air quality. Once air problems have taken hold, other reduction methods need to be applied utilising a more reactive approach. A key requirement for the control of concentration and exposure of airborne pollutants to an acceptable level is to be able to conduct real-time measurements of these pollutants. This paper provides a review of airborne pollution including methods to both measure and control the concentration of pollutants in livestock buildings

    Thermal finite-element analysis of space shuttle main engine turbine blade

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    Finite-element, transient heat transfer analyses were performed for the first-stage blades of the space shuttle main engine (SSME) high-pressure fuel turbopump. The analyses were based on test engine data provided by Rocketdyne. Heat transfer coefficients were predicted by performing a boundary-layer analysis at steady-state conditions with the STAN5 boundary-layer code. Two different peak-temperature overshoots were evaluated for the startup transient. Cutoff transient conditions were also analyzed. A reduced gas temperature profile based on actual thermocouple data was also considered. Transient heat transfer analyses were conducted with the MARC finite-element computer code

    Problems of Combining Absolute and Relative Points and Area Symbols, With Special Reference to Mapping Industrial Workers in North and West Sumatera, Indonesia

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    Abstract. The most important phase of cartographic processes is the selection of map symbols for data presentations, since the effectiveness of maps as a medium of communication depends on this selection. A great variety of map symbols can be chosen. This study shows how to utilize symbols in solving a typical problem of a map showing distribution.Sari. Salah satu tahap yang paling menentukan dalam proses kartografi adalah pemilihan simbol untuk memetakan data. Hal ini disebabkan oleh kenyataan bahwa symbol itu banyak sekali macamnya. Manfaat peta sebagai media komunikasi akan sangat terasa bila symbol yang dipilih tepat atau cocok dengan maksud serta tujuan pembuatan peta tadi. Tulisan ini membahas bagaimana cara memilih serta menggunakan symbol untuk suatu persoalan, khususnya yang menyangkut masalah distribusi

    Plastics and Environment: Is There a Happy Medium?

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    In 2013 alone, 56 million tons of Poly(ethylene terephthalate) (PET) was produced worldwide. It’s low cost of production, coupled with desirable properties such as high durability and plasticity has led to its extensive use in many different applications, from mobile phones to medical equipment to clothing. Demand for PET is steadily increasing year by year. However, PET is mineral-based and is a non-degradable material due to its synthetic nature. It accumulates within the environment globally, and this has led to collective global efforts for developing strategies to tackle the issue using various different options. Biopolymers such as Polyhydroxyalkanoate (PHA) present themselves as a possible solution and as suitable alternative to help manage the ever-rising global demand for plastics as well as alleviating the global environmental crisis arising from non-degradable plastics. Capable to be produced in an eco-friendly manner and possessing biodegradable properties, biopolymers should be set to replace non-degradable plastics, but despite extensive research on production of biodegradable plastics, the cost of their production is too high to lend them to large-scale production. This project focuses on economic production of PHAs. In this context, several approaches are adopted. Cheaper media such as orange peel, wheat bran, and spirulina with other quality enhancing ingredients have been tried; dual polymer production has been proved a possible option, and stage-wise fermentations, appart from fed-batch have been tried. Furthermore, downstream processing strategies such as planned time of harvest have the potential to attenuate adverse effects of extraction methods for PHA extraction. A holistic approach promises positive future for biopolymer industry
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