4,455 research outputs found
The higher-order C_n dispersion coefficients for hydrogen
The complete set of 2nd, 3rd and 4th order van der Waals coefficients, C_n up
to n=32 for the H(1s)-H(1s) dimer are computed using pseudo-states to evaluate
the appropriate sum rules. A study of the convergence pattern for n<=16
indicates that all the C_n (n<=16) coefficients are accurate to 13 significant
digits. The relative size of the 4th-order C^4_n to the 2nd-order C^2_n
coefficients is seen to increase as n increases and at n=32 the 4th-order term
is actually larger.Comment: 5 pages under review PR
Positronic complexes with unnatural parity
The structure of the unnatural parity states of PsH, LiPs, NaPs and KPs are
investigated with the configuration interaction and stochastic variational
methods. The binding energies (in hartree) are found to be 8.17x10-4,
4.42x10-4, 15.14x10-4 and 21.80x10-4 respectively. These states are constructed
by first coupling the two electrons into a configuration which is predominantly
3Pe, and then adding a p-wave positron. All the active particles are in states
in which the relative angular momentum between any pair of particles is at
least L = 1. The LiPs state is Borromean since there are no 3-body bound
subsystems (of the correct symmetry) of the (Li+, e-, e-, e+) particles that
make up the system. The dominant decay mode of these states will be radiative
decay into a configuration that autoionizes or undergoes positron annihilation.Comment: 10 pages RevTeX, 6 figures, in press Phys.Rev.
Convergence of CI single center calculations of positron-atom interactions
The Configuration Interaction (CI) method using orbitals centered on the
nucleus has recently been applied to calculate the interactions of positrons
interacting with atoms. Computational investigations of the convergence
properties of binding energy, phase shift and annihilation rate with respect to
the maximum angular momentum of the orbital basis for the e^+Cu and PsH bound
states, and the e^+-H scattering system were completed. The annihilation rates
converge very slowly with angular momentum, and moreover the convergence with
radial basis dimension appears to be slower for high angular momentum. A number
of methods of completing the partial wave sum are compared, an approach based
on a Delta X_J = a/(J + 1/2)^n + b/(J + 1/2)^(n+1) form (with n = 4 for phase
shift (or energy) and n = 2 for the annihilation rate) seems to be preferred on
considerations of utility and underlying physical justification.Comment: 23 pages preprint RevTeX, 11 figures, submitted to PR
Evaluation of Effects of Wastewater Treatment Discharge on Estuarine Water Quality
This report marks the completion of a two-year project focused on observed and estimated effects of wastewater treatment facilities (WWTFs) on estuarine water quality within the New Hampshire (NH) Seacoast region. This study was designed and carried out in an effort to help the NH Department of Environmental Services (NHDES) and NH Estuaries Project (NHEP) evaluate the effects of WWTF effluent quality on bacterial and nutrient concentrations in New Hampshire’s estuarine waters, as well as to help NHDES/NHEP identify related WWTF infrastructure problems. An extensive database of bacterial and nutrient concentrations in effluent collected post-disinfection from 9 NH WWTFs and 2 Maine WWTFs that discharge into the Great Bay and Hampton/Seabrook estuaries was developed. The data were used to determine ratios between different bacterial indicators in WWTF effluent, estimates of in-stream bacterial concentrations following effluent discharge to receiving waters and estimates of nutrient loading from selected WWTFs
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Investigative Journalism and Human Rights
The early years of the twenty-first century may have brought a renewed global impetus to investigative journalism’s concern with human rights. Founded in normative views of journalism as a social watchdog, and the specificities of its investigative turn as combative and challenging, investigative journalism has been intimately connected with the recognition, promotion and protection of human rights over more than two centuries. The waxing of investigative journalism appears to occur when social disruption coincides with enhanced communication capabilities – from the early throes of modernisation to current processes of democratisation, globalisation and digitisation. Investigative journalism acts as a form of social conscience, exposing lapses in a commitment to human rights. At the same time, investigative journalism lays claim to its own right to freedom of expression
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A socially-responsible educational response to routine-biased technological change in journalism: Fostering employability among journalists in the United Kingdom
Journalism in the UK straddles the divide between high- and middle-skilled employment. Since the 1970s those determined to be middle-skilled have been vulnerable to increasing difficulty in finding employment, deepening insecurity of employment and limited opportunities for advancement as work has been routinized and off-shored. This is especially so for young people. Moreover, journalism is also a short-term career. However, at the same time, journalism has significantly upskilled through graduatisation, and currently the most favoured route into journalism is through a postgraduate taught (PGT) qualification, such as a Master’s degree. This study examines the career experiences of 889 alumni of a PGT newspaper journalism course and maps them to employment trends. It is argued that the socially responsible approach is to prepare alumni for life during and after journalism through the development of their employability, rather than focusing on their immediate employment prospects
Large dimension Configuration Interaction calculations of positron binding to the group II atoms
The Configuration Interaction (CI) method is applied to the calculation of
the structures of a number of positron binding systems, including e+Be, e+Mg,
e+Ca and e+Sr. These calculations were carried out in orbital spaces containing
about 200 electron and 200 positron orbitals up to l = 12. Despite the very
large dimensions, the binding energy and annihilation rate converge slowly with
l, and the final values do contain an appreciable correction obtained by
extrapolating the calculation to the l to infinity limit. The binding energies
were 0.00317 hartree for e+Be, 0.0170 hartree for e+Mg, 0.0189 hartree for
e+Ca, and 0.0131 hartree for e+Sr.Comment: 13 pages, no figs, revtex format, Submitted to PhysRev
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Developing professionalism in new IT graduates? Who needs it?
A new graduate may require a period of ‘acclimatisation’ through a process of ‘developing their professionalism’ to fit into their work environment. The e-Skills UK Technology Counts Insights 2010 report suggests that 110,500 new entrants a year are required to fill IT & Telecoms professional job roles, with 20,800 coming from education (predominantly graduate level and higher). However, 43% of recruiters were reporting a lack of suitable candidates for IT & Telecoms posts where growing importance will be placed on relationship management, business process analysis and design, project and programme management. IT & Telecoms professionals are increasingly expected to be multi-skilled, with sophisticated business and interpersonal skills as well as technical competence. As the report also says: ‘UK growth will continue to be primarily in high-value roles with an increasing need for customer and business-oriented skills as well as sophisticated technical competencies.’
The diverse needs and requirements of the IT sector, as specified by various employer groups and professional bodies including BCS, IET, eSkills, the CBI and the SFIA Foundation, are discussed. According to the CBI, ‘62% of entrants to the IT sector need to draw on managerial and professional business skills almost immediately.’ For organisations to succeed, their IT graduate recruits must supplement their IT skills with managerial and professional business skills. Well considered CPD will ensure that recent graduates can enhance their ‘academic’ skills with the necessary work-based skills for the benefit of both themselves and their new employer. The focus of the improvement will balance the student-centred needs for development and the engaging employer’s commercial needs
Effective oscillator strength distributions of spherically symmetric atoms for calculating polarizabilities and long-range atom-atom interactions
Effective oscillator strength distributions are systematically generated and
tabulated for the alkali atoms, the alkaline-earth atoms, the alkaline-earth
ions, the rare gases and some miscellaneous atoms. These effective
distributions are used to compute the dipole, quadrupole and octupole static
polarizabilities, and are then applied to the calculation of the dynamic
polarizabilities at imaginary frequencies. These polarizabilities can be used
to determine the long-range , and atom-atom interactions
for the dimers formed from any of these atoms and ions, and we present tables
covering all of these combinations
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