164 research outputs found

    Radiological and Chemical Toxicity Due to Ingestion of Uranium through Drinking Water in the Environment of Bangalore, India

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    Groundwater samples collected from 96 bore wells in the study area (city of Bangalore) were analysed for concentration of natural uranium using laser-induced fluorimetry. The risk to the population of the region associated with radiological and chemical toxicity of uranium due to its ingestion through drinking water over a lifetime was estimated. The concentration of uranium was found to be in the range 0.136 to 2027.5 μg L−1 with an average value of 92.42 μg L−1. In the present study, about 61% of the samples show concentrations of uranium within the safe limit of 30 μg L−1 as set by the world health organisation. The radiological risk estimated as lifetime cancer risk is in the range 4.3  ×  10−7 to 6.4  ×  10−3 with an average of 2.9  ×  10−4. The chemical toxicity risk measured as lifetime average daily dose is found to range from 0.005 to 75.42 μg kg−1 d−1. The reference dose estimated as 1.12 μg kg−1 d−1 was used to assess the chemical toxicity. The results indicate that the chemical toxicity due to ingestion of uranium through drinking water is of more concern than the radiological toxicity. The present study, being the first of its kind in this region, will augment the database of uranium in groundwater

    Further Thoughts on Mega-Accounting and the Need for Standards

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    This paper continues previous research (Mathews 1984, 1997b, 2000a, 2000b, 2003) into developinga proposal for a system of comprehensive reporting based on a concept called megaaccounting.The ideas in mega-accounting are similar to those behind GRI (2002) and triplebottom line (TBL) reporting (Elkington 1997), but with a different underlying philosophy, asocial contract approach compared to one based on organisational legitimacy or the need formanagement to drive sustainability and sustainable capitalism which is sometimes called ‘thebusiness case’. The paper attempts to develop the concept of mega-accounting by identifyingthe purpose underlying the reports, identifying the basis of a conceptual framework and providingan indication of the content that social and environmental accounting reports may include inthe future. Of necessity the research perspective is normative and deductive, as is much of theprocess of developing accounting standards, the model upon which it is argued social and environmentalaccounting should be based. The paper concludes by reiterating that the way forwardfor social and environmental accounting and reporting is for a conceptual framework to beagreed and standards developed via a normative-pragmatic process that will provide the basisfor comprehensive, audited, corporate reports encompassing the social, environmental and economicdimension. Furthermore, additional work is needed on the areas of macro-social accountingand externalities in order to develop a comprehensive framework. Copyright © www.iiste.or

    Towards the justification and development of a more socially relevant accounting

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    This thesis presents arguments in favour of the expenditure of resources on additional disclosures in both the private and public sectors, together with a system of organising the additional reports and other forms of accountability statements. The study is evolutionary rather than revolutionary and envisages the gradual development of a more socially relevant accounting which, on the whole, is guided by the basic principles of current Anglo-American accounting. The objective of the overall thesis is to enable a more socially relevant accounting to be developed, operationalised, practiced and taught within our basic accounting framework. [Continues]

    A Hedged Monte Carlo Approach to Real Option Pricing

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    In this work we are concerned with valuing optionalities associated to invest or to delay investment in a project when the available information provided to the manager comes from simulated data of cash flows under historical (or subjective) measure in a possibly incomplete market. Our approach is suitable also to incorporating subjective views from management or market experts and to stochastic investment costs. It is based on the Hedged Monte Carlo strategy proposed by Potters et al (2001) where options are priced simultaneously with the determination of the corresponding hedging. The approach is particularly well-suited to the evaluation of commodity related projects whereby the availability of pricing formulae is very rare, the scenario simulations are usually available only in the historical measure, and the cash flows can be highly nonlinear functions of the prices.Comment: 25 pages, 14 figure

    Testing Broken U(1) Symmetry in a Two-Component Atomic Bose-Einstein Condensate

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    We present a scheme for determining if the quantum state of a small trapped Bose-Einstein condensate is a state with well defined number of atoms, a Fock state, or a state with a broken U(1) gauge symmetry, a coherent state. The proposal is based on the observation of Ramsey fringes. The population difference observed in a Ramsey fringe experiment will exhibit collapse and revivals due to the mean-field interactions. The collapse and revival times depend on the relative strength of the mean-field interactions for the two components and the initial quantum state of the condensate.Comment: 20 Pages RevTex, 3 Figure

    Amplitudes With Different Helicity Configurations Of Noncommutative QED

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    The amplitudes of purely photonic and photon{2-fermion processes of non- commutative QED (NCQED) are derived for different helicity configurations of photons. The basic ingredient is the NCQED counterpart of Yang-Mills recursion relations by means of Berends and Giele. The explicit solutions of recursion relations for NCQED photonic processes with special helicity configurations are presented.Comment: 23 pages, 2 figure

    Prioritising prevention strategies for patients in antiretroviral treatment programmes in resource-limited settings

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    Expanded access to antiretroviral therapy (ART) offers opportunities to strengthen HIV prevention in resource-limited settings. We invited 27 ART programmes from urban settings in Africa, Asia and South America to participate in a survey, with the aim to examine what preventive services had been integrated in ART programmes. Twenty-two programmes participated; eight (36%) from South Africa, two from Brazil, two from Zambia and one each from Argentina, India, Thailand, Botswana, Ivory Coast, Malawi, Morocco, Uganda and Zimbabwe and one occupational programme of a brewery company included five countries (Nigeria, Republic of Congo, Democratic Republic of Congo, Rwanda and Burundi). Twenty-one sites (96%) provided health education and social support, and 18 (82%) provided HIV testing and counselling. All sites encouraged disclosure of HIV infection to spouses and partners, but only 11 (50%) had a protocol for partner notification. Twenty-one sites (96%) supplied male condoms, seven (32%) female condoms and 20 (91%) provided prophylactic ART for the prevention of mother-to child transmission. Seven sites (33%) regularly screened for sexually transmitted infections (STI). Twelve sites (55%) were involved in activities aimed at women or adolescents, and 10 sites (46%) in activities aimed at serodiscordant couples. Stigma and discrimination, gender roles and funding constraints were perceived as the main obstacles to effective prevention in ART programmes. We conclude that preventive services in ART programmes in lower income countries focus on health education and the provision of social support and male condoms. Strategies that might be equally or more important in this setting, including partner notification, prompt diagnosis and treatment of STI and reduction of stigma in the community, have not been implemented widely

    Pair Production of Neutral Higgs Bosons through Noncommutative QED Interactions at Linear Colliders

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    We study the feasibility of detecting noncommutative (NC) QED through neutral Higgs boson (H) pair production at linear colliders (LC). This is based on the assumption that H interacts directly with photon in NCQED as suggested by symmetry considerations and strongly hinted by our previous study on \pi^0-photon interactions. We find the following striking features as compared to the standard model (SM) result: (1) generally larger cross sections for an NC scale of order 1 TeV; (2) completely different dependence on initial beam polarizations; (3) distinct distributions in the polar and azimuthal angles; and (4) day-night asymmetry due to the Earth's rotation. These will help to separate NC signals from those in the SM or other new physics at LC. We emphasize the importance of treating properly the Lorentz noninvariance problem and show how the impact of the Earth's rotation can be used as an advantage for our purpose of searching for NC signals.Comment: 12 pages, 3 figures using axodraw.sty; v2: proof version in Phys. Rev. D, minor rewordin

    Recoil-Induced-Resonances in Nonlinear, Ground-State, Pump-Probe Spectroscopy

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    A theory of pump-probe spectroscopy is developed in which optical fields drive two-photon Raman transitions between ground states of an ensemble of three-level Λ\Lambda atoms. Effects related to the recoil the atoms undergo as a result of their interactions with the fields are fully accounted for in this theory. The linear absorption coefficient of a weak probe field in the presence of two pump fields of arbitrary strength is calculated. For subrecoil cooled atoms, the spectrum consists of eight absorption lines and eight emission lines. In the limit that χ1χ2\chi_{1}\ll \chi_{2}, where χ1\chi_{1} and χ2\chi_{2} are the Rabi frequencies of the two pump fields, one recovers the absorption spectrum for a probe field interacting with an effective two-level atom in the presence of a single pump field. However when χ1χ2\chi_{1}\gtrsim \chi_{2}, new interference effects arise that allow one to selectively turn on and off some of these recoil induced resonances.Comment: 30 pages, 8 figures. RevTex. Submitted to Phys. Rev. A, Revised versio

    The composition of the protosolar disk and the formation conditions for comets

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    Conditions in the protosolar nebula have left their mark in the composition of cometary volatiles, thought to be some of the most pristine material in the solar system. Cometary compositions represent the end point of processing that began in the parent molecular cloud core and continued through the collapse of that core to form the protosun and the solar nebula, and finally during the evolution of the solar nebula itself as the cometary bodies were accreting. Disentangling the effects of the various epochs on the final composition of a comet is complicated. But comets are not the only source of information about the solar nebula. Protostellar disks around young stars similar to the protosun provide a way of investigating the evolution of disks similar to the solar nebula while they are in the process of evolving to form their own solar systems. In this way we can learn about the physical and chemical conditions under which comets formed, and about the types of dynamical processing that shaped the solar system we see today. This paper summarizes some recent contributions to our understanding of both cometary volatiles and the composition, structure and evolution of protostellar disks.Comment: To appear in Space Science Reviews. The final publication is available at Springer via http://dx.doi.org/10.1007/s11214-015-0167-
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