9,552 research outputs found

    Linear root water uptake by vegetation

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    The performance of a simple model with a linear root water extraction term that varies with time is presented in this paper. The research is based on the use of a one-dimensional form of Richard’s Equation for unsaturated moisture flow including a sink term. A numerical solution has been achieved via the finite element method for spatial discretisation along with a finite difference time-marching scheme. The model is assessed via a series of simulations of water uptake beneath uniform crop cover. A good correlation between the field data and simulated results has been achieved. This relatively straight forward approach is seemed more suitable for development and application to a range of geoengineering problems such as slope stability, shrinkage and heave prediction

    EQUAL PAY – THE TIME-BOMB UNDER PAY STRUCTURES IN ROMANIA

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    One of the major consequences of Romania joining the European Union is its obligation to implement European Directives with regard to employment protection. One aspect of that is likely to have major social and cost implications is the legislation regarding equal pay for men and women. The dimension of equal pay for work that is the same or broadly similar is relatively straightforward. The more complicated and more far reaching requirement is for equal pay for men and women for work of equal value. In determining whether jobs are of equal value regard has to had in particular to effort, skill and decision making. Comparisons are valid with other jobs in the same organisation but not between organisations. In addition comparisons are only legally valid if they are on the basis that a person of the opposite sex is being paid more for work of equivalent value. Such comparisons are subjective and often very complicated. Job evaluation schemes can help in creating a framework for comparison but being inherently subjective are open to challenge. The situation is further complicated by the fact that comparisons can also be made on any one element of the remuneration package. Experience in the U.K. and other member EU countries is that equal pay claims are very much on the rise, can take years to resolve and can be hugely expensive. Although legal costs can be significant the main costs are in settling group claims and the ‘knock-on’ effect on the rest of an organisation’s pay structure. Whilst it may take time for this development to gather pace in Romania now is the time for organisations to review their pay structures and take preventative action to try and reduce the conflict that will inevitably occur.employment protection, equal pay, equal pay for work of equal value, pay structures

    Fitting Pulsar Wind Tori. II. Error Analysis and Applications

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    We have applied the torus fitting procedure described in Ng & Romani (2004) to PWNe observations in the Chandra data archive. This study provides quantitative measurement of the PWN geometry and we characterize the uncertainties in the fits, with statistical errors coming from the fit uncertainties and systematic errors estimated by varying the assumed fitting model. The symmetry axis Ψ\Psi of the PWN are generally well determined, and highly model-independent. We often derive a robust value for the spin inclination ζ\zeta. We briefly discuss the utility of these results in comparison with new radio and high energy pulse measurementsComment: 15 pages, 3 figures, ApJ in pres

    Importance of an Astrophysical Perspective for Textbook Relativity

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    The importance of a teaching a clear definition of the ``observer'' in special relativity is highlighted using a simple astrophysical example from the exciting current research area of ``Gamma-Ray Burst'' astrophysics. The example shows that a source moving relativistically toward a single observer at rest exhibits a time ``contraction'' rather than a ``dilation'' because the light travel time between the source and observer decreases with time. Astrophysical applications of special relativity complement idealized examples with real applications and very effectively exemplify the role of a finite light travel time.Comment: 5 pages TeX, European Journal of Physics, in pres

    Tax Techniques of Bootstrap Acquisitions

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    Neutrinos from Early-Phase, Pulsar-Driven Supernovae

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    Neutron stars, just after their formation, are surrounded by expanding, dense, and very hot envelopes which radiate thermal photons. Iron nuclei can be accelerated in the wind zones of such energetic pulsars to very high energies. These nuclei photo-disintegrate and their products lose energy efficiently in collisions with thermal photons and with the matter of the envelope, mainly via pion production. When the temperature of the radiation inside the envelope of the supernova drops below 3×106\sim 3\times 10^6 K, these pions decay before losing energy and produce high energy neutrinos. We estimate the flux of muon neutrinos emitted during such an early phase of the pulsar - supernova envelope interaction. We find that a 1 km2^2 neutrino detector should be able to detect neutrinos above 1 TeV within about one year after the explosion from a supernova in our Galaxy. This result holds if these pulsars are able to efficiently accelerate nuclei to energies 1020\sim 10^{20} eV, as postulated recently by some authors for models of Galactic acceleration of the extremely high energy cosmic rays (EHE CRs).Comment: 16 pages, 3 figures, revised version submitted to Ap

    Seventy years of sex education in Health Education Journal: a critical review

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    This paper examines key debates and perspectives on sex education in Health Education Journal (HEJ), from the date of the journal’s first publication in March 1943 to the present day. Matters relating to sexuality and sexual health are revealed to be integral to HEJ’s history. First published as Health and Empire (1921 – 1942), a key purpose of the journal since its inception has been to share information on venereal disease and its prevention within the UK and across the former British Empire. From 1943 to the present day, discussions on sex education in the newly-christened HEJ both reflect and respond to evolving socio-cultural attitudes towards sexuality in the UK. Changing definitions of sex education across the decades are examined, from the prevention of venereal disease and moral decline in war-time Britain in the 1940s, to a range of responses to sexual liberation in the 1960s and 1970s; from a focus on preventing sexually-transmitted infections, teenage pregnancy and HIV in the 1980s, to the provision of sexual health services alongside sex education in the 2000s. Over the past 70 years, a shift from prevention of pre-marital sexual activity to the management of its outcomes is apparent; however, while these changes over time are notable, perhaps the most striking findings of this review are the continuities in arguments for and against the discussion of sexual issues. After more than 70 years of debate, it would seem that there is little consensus concerning motivations for and the content of sex education
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