84,399 research outputs found
Redefining engineering education: the reflective practice of product design engineering
The University of Glasgow and the School of Design at the Glasgow School of Art have joined forces to redefine the nature of an engineering curriculum and produce a degree program that is rich in both creative design culture and design engineering skills. Graduates of this program are able, creatively, to critically analyze, evaluate and solve a diverse range of design and engineering problems, including their own life-long learning. This innovative curriculum enables graduates to enter the workforce as true reflective practitioners. This paper examines what can be achieved as a result of breaking down traditional engineering education barriers
Layout tool Patent
Design and development of layout tool for machine shop use to locate point in precise reference to straight or bowed reference edg
Positron cooling and annihilation in noble gases
Understanding the dynamics of positron cooling in gases, including the
fraction of positrons surviving to thermalisation, is critical for accurate
interpretation of positron lifetime spectra, for the development of efficient
positron cooling in traps and accumulators, and for a cryogenically cooled,
ultra-high-energy-resolution, trap-based positron beam. Here, positron cooling
and annihilation in noble gases is simulated using accurate scattering and
annihilation cross sections calculated \emph{ab initio} with many-body theory.
It is shown that a strikingly small fraction of positrons survive to
thermalisation: 0.1 in He, 0 in Ne (due to cooling effectively
stalling in the relatively deep momentum-transfer cross-section minimum),
0.15 in Ar, 0.05 in Kr and 0.01 in Xe. For Xe, the
time-varying annihilation rate is shown to be highly
sensitive to the depletion of the distribution due to annihilation,
conclusively explaining the long-standing discrepancy between gas-cell and
trap-based measurements in Xe. The \emph{ab initio} calculations enable the
first simultaneous probing of the energy dependence of the the scattering cross
section and annihilation rate. Overall, the use of the accurate atomic data
gives in close agreement with experiment for all
noble gases except Ne, the experiment for which is proffered to have suffered
from incomplete knowledge of the fraction of positrons surviving to
thermalisation and/or the presence of impurities.Comment: Supplementary videos of positron cooling in He, Ne, Ar, Kr and Xe at
http://www.am.qub.ac.uk/users/dgreen09/coolingvideos.html ; This version
contains additional References, is significantly reduced in size and has
improved tex
An Introduction to Gauge Gravity Duality and Its Application in Condensed Matter
The past few years have witnessed a remarkable crossover of string
theoretical ideas from the abstract world of geometrical forms to the concrete
experimental realm of condensed matter physics. The basis for this ---
variously known as holography, the AdS/CFT correspondence or gauge-gravity
duality --comes from notions right at the cutting edge of string theory.
Nevertheless, the insights afforded can often be expressed in ways very
familiar to condensed matter physicists, such as relationships between response
functions and new sum rules.
The aim of this short, introductory review is to survey the ideas
underpinning this crossover, in a way that -- as far as possible -- strips them
of sophisticated mathematical formalism, whilst at the same time retaining
their fundamental essence. I will sketch the areas in which progress has been
made to date and highlight where the challenges and open questions lie.
Finally, I will attempt to give a perspective upon these ideas. What
contribution can we realistically expect from this approach and how might it be
accommodated into the canon of condensed matter theory? Inevitably, any attempt
to do this in such a rapidly evolving field will be superseded by events.
Nevertheless, I hope that this will provide a useful way to think about
gauge-gravity duality and the uncharted directions in which it might take us.Comment: Unedited version of article published in Contemporary Physics.
Intended for advanced final-year undergraduate
Probing positron cooling in noble gases via annihilation spectra
spectra for positron annihilation in noble-gas atoms are calculated
using many-body theory for positron momenta up to the positronium-formation
threshold. This data is used, together with time-evolving positron-momentum
distributions determined in [arXiv:1706.01434 (2017)], to calculate the
time-varying spectra produced during positron cooling in noble gases.
The -spectra and their and shape parameters are
shown to be sensitive probes of the time evolution of the positron momentum
distribution, and thus provide a means of studying positron cooling that is
complementary to positron lifetime spectroscopy.Comment: This version contains minor update to references, otherwise unchange
Women’s Decisions about Mental Health Treatment in the Perinatal Period
This study examined a mother’s decision-making process in regards to mental health treatment for emotional difficulties during pregnancy and/or in the postpartum period. The literature shows that different factors influence a woman’s ability and willingness to seek services, including demographic factors, cultural factors, and interactions with healthcare providers and acquaintances. A sample of women who experienced emotional difficulties in the perinatal period was recruited through social media. Participants answered an anonymous electronic survey; the quantitative data was analyzed through SPSS, and the qualitative data was aggregated by themes. Quantitative findings indicate that age might be an influencing factor for women deciding to speak to a healthcare provider, but the same was not true for socioeconomic status or having already discussed the matter with an acquaintance. Qualitative answers replicate previous findings that embarrassment and confusion about what is “normal” emotional behavior in the perinatal period are deterrents to seeking treatment
A tale of two cinnamons: A comparative review of the clinical evidence of Cinnamomum verum and C. cassia as diabetes interventions
Objective: This review investigates the effectiveness of two cinnamon species, Cinnamomum verum and C. cassia, in diabetes management; their impact on related health conditions and relevant parameters in healthy individuals and safety issues.
Methods: PubMed, Cochrane Library, and ScienceDirect were searched from 2000 up to April 2018 for clinical trials using either C. verum or C. cassia in controlling blood glucose and other diabetes-related parameters and conditions.
Results: A total of twenty-five studies (n=997) were included for reviewing clinical evidence. Among these trials, fifteen studies investigated the effects on type II diabetes mellitus (T2DM) patients (n=831), four investigated subjects with related clinical conditions (n=82), and six investigated healthy individuals (n=84). Nineteen studies used C. cassia and six used C. verum. Results suggested C. cassia helped manage diabetes at 3-6g, while the effectiveness of C. verum remained inconclusive. In addition, the chemical properties of C. cassia and C. verum differ considerably. Of note, C. cassia contains high levels of the potentially hepatotoxic constituent coumarin. A skin rash was the only adverse event reported.
Conclusion: While evidence supports the therapeutic benefit of C. cassia, interchangeability of C. cassia and C. verum remains inconclusive. Further research is warranted to address the effectiveness and safety of these cinnamon species. Given the potential hepatotoxicity of C. cassia, RCTs that include liver function tests are required. Robust RCTs on C. verum are recommended to establish if its efficacy can match its safety profile
-ray spectra and enhancement factors for positron annihilation spectra with core-electrons
Many-body theory is developed to calculate the -spectra for positron
annihilation with valence and core electrons in the noble gas atoms. A proper
inclusion of correlation effects and core annihilation provides for an accurate
description of the measured spectra [Iwata \textit{et al.}, Phys. Rev. Lett.
{\bf 79}, 39 (1997)]. The theory enables us to calculate the enhancement
factors , which describe the effect of electron-positron
correlations for annihilation on individual electron orbitals . We find
that the enhancement factors scale with the orbital ionization energy
(in electron-volt), as ,
where ~eV, ~eV and .Comment: 5 pages, 5 figure
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