2,587 research outputs found
An exploration of the pedagogies employed to integrate knowledge in work-integrated learning
This article describes a three‐sector, national research project that investigated the integration aspect of work‐integrated learning (WIL). The context for this study is three sectors of New Zealand higher education: business and management, sport, and science and engineering, and a cohort of higher educational institutions that offer WIL/cooperative education in variety of ways. The aims of this study were to investigate the pedagogical approaches in WIL programs that are currently used by WIL practitioners in terms of learning, and the integration of academic‐workplace learning. The research constituted a series of collective case studies, and there were two main data sources — interviews with three stakeholder groups (namely employers, students, and co‐op practitioners), and analyses of relevant documentation (e.g., course/paper outlines, assignments on reflective practice, portfolio of learning, etc.). The research findings suggest that there is no consistent mechanism by which placement coordinators, off‐campus supervisors, or mentors seek to employ or develop pedagogies to foster learning and the integration of knowledge. Learning, it seems, occurs by means of legitimate peripheral participation with off‐campus learning occurring as a result of students working alongside professionals in their area via an apprenticeship model of learning. There is no evidence of explicit attempts to integrate on‐ and off‐campus learning, although all parties felt this would and should occur. However, integration is implicitly or indirectly fostered by a variety of means such as the use of reflective journals
Oblique Parameter Constraints on Large Extra Dimensions
We consider the Kaluza-Klein scenario in which gravity propagates in the
dimensional bulk of spacetime and the Standard Model particles are
confined to a 3-brane. We calculate the gauge boson self-energy corrections
arising from the exchange of virtual gravitons and present our results in the
-formalism. We find that the new physics contributions to , and
decouple in the limit that the string scale goes to infinity. The oblique
parameters constrain the lower limit on . Taking the quantum gravity
cutoff to be ,
-parameter constraints impose TeV for at the 1
level. -parameter constraints impose TeV for .Comment: Version to appear in PR
Effect of the shear-to-compressive force ratio in puncture tests quantifying watermelon mechanical properties
a b s t r a c t Because texture is a primary driver of watermelon acceptability, the development of methods to test for small differences in texture between new cultivars would be of great utility to fruit breeding efforts. The objective was to investigate the effect of the shear-to-compressive force ratio in puncture tests on watermelon, then design new probes that would improve the test's sensitivity. A new hollow probe design of increased shear force (compactness = 11.6 mm 2 /mm 2 ) was more sensitive at quantifying watermelon tissue mechanical properties when compared to the industry standard Magness-Taylor probe (compactness = 1 mm 2 /mm 2 ). Compressive force applied is constant between the two. The hollow probe was more sensitive to differences between tissue types, though was not able to discriminate between cultivars, using the maximum force value. Based upon the improved performance of the hollow probe with tissue types, a high-shear 'snowflake' probe was designed and compared to the hollow and MagnessTaylor probes. The Magness-Taylor probe misclassified tissue types in 42% of samples tested, while the hollow and snowflake probes performed better, misclassifying 32% and 34% of samples, respectively. This was an improved accuracy over the Magness-Taylor, but the hollow and snowflake probes were not significantly different (a = 0.05) from each other. These results suggest that of the two, the hollow probe, due to its simplicity, offers an improvement over the industry standard Magness-Taylor in maximum force parameter applications
Effects of Extra Space-time Dimensions on the Fermi Constant
Effects of Kaluza-Klein excitations associated with extra dimensions with
large radius compactifications on the Fermi constant are explored. It is shown
that the current precision determinations of the Fermi constant, of the fine
structure constant, and of the W and Z mass put stringent constraints on the
compactification radius. The analysis excludes one extra space time dimension
below TeV, and excludes 2, 3 and 4 extra space dimensions opening
simultaneously below 3.5 TeV, 5.7 TeV and 7.8 TeV at the .
Implications of these results for future collider experiments are discussed.Comment: 12 pages including one figur
Phenomenology, Astrophysics and Cosmology of Theories with Sub-Millimeter Dimensions and TeV Scale Quantum Gravity
We recently proposed a solution to the hierarchy problem not relying on
low-energy supersymmetry or technicolor. Instead, the problem is nullified by
bringing quantum gravity down to the TeV scale. This is accomplished by the
presence of new dimensions of sub-millimeter size, with the SM
fields localised on a 3-brane in the higher dimensional space. In this paper we
systematically study the experimental viability of this scenario. Constraints
arise both from strong quantum gravitational effects at the TeV scale, and more
importantly from the production of massless higher dimensional gravitons with
TeV suppressed couplings. Theories with are safe due mainly to the
infrared softness of higher dimensional gravity. For , the six dimensional
Planck scale must be pushed above TeV to avoid cooling SN1987A and
distortions of the diffuse photon background. Nevertheless, the particular
implementation of our framework within type I string theory can evade all
constraints, for any , with string scale TeV. We also
explore novel phenomena resulting from the existence of new states propagating
in the higher dimensional space. The Peccei-Quinn solution to the strong CP
problem is revived with a weak scale axion in the bulk. Gauge fields in the
bulk can mediate repulsive forces times stronger than
gravity at sub-mm distances, and may help stabilize the proton.
Higher-dimensional gravitons produced on our brane and captured on a different
"fat" brane can provide a natural dark matter candidate.Comment: 51 pages, late
Stochastic Inflation Revisited: Non-Slow Roll Statistics and DBI Inflation
Stochastic inflation describes the global structure of the inflationary
universe by modeling the super-Hubble dynamics as a system of matter fields
coupled to gravity where the sub-Hubble field fluctuations induce a stochastic
force into the equations of motion. The super-Hubble dynamics are ultralocal,
allowing us to neglect spatial derivatives and treat each Hubble patch as a
separate universe. This provides a natural framework in which to discuss
probabilities on the space of solutions and initial conditions. In this article
we derive an evolution equation for this probability for an arbitrary class of
matter systems, including DBI and k-inflationary models, and discover
equilibrium solutions that satisfy detailed balance. Our results are more
general than those derived assuming slow roll or a quasi-de Sitter geometry,
and so are directly applicable to models that do not satisfy the usual slow
roll conditions. We discuss in general terms the conditions for eternal
inflation to set in, and we give explicit numerical solutions of highly
stochastic, quasi-stationary trajectories in the relativistic DBI regime.
Finally, we show that the probability for stochastic/thermal tunneling can be
significantly enhanced relative to the Hawking-Moss instanton result due to
relativistic DBI effects.Comment: 38 pages, 2 figures. v3: minor revisions; version accepted into JCA
Effects of Extra Dimensions on Unitarity and Higgs Boson Mass
We study the unitarity constraint on the two body Higgs boson elastic
scattering in the presence of extra dimensions. The contributions from exchange
of spin-2 and spin-0 Kaluza-Klein states can have large effect on the partial
wave amplitude. Unitarity condition restrict the maximal allowed value for the
ratio of the center of mass energy to the gravity scale to be less than
one. Although the constraint on the standard Higgs boson mass for of order
one is considerably relaxed, for small the constraint is similar to that in
the Standard Model. The resulting bound on the Higgs boson mass is not
dramatically altered if perturbative calculations are required to be valid up
to the maximal allowed value for .Comment: References added, RevTex, 9 pages with two figure
Fluxes and Warping for Gauge Couplings in F-theory
We compute flux-dependent corrections in the four-dimensional F-theory
effective action using the M-theory dual description. In M-theory the 7-brane
fluxes are encoded by four-form flux and modify the background geometry and
Kaluza-Klein reduction ansatz. In particular, the flux sources a warp factor
which also depends on the torus directions of the compactification fourfold.
This dependence is crucial in the derivation of the four-dimensional action,
although the torus fiber is auxiliary in F-theory. In M-theory the 7-branes are
described by an infinite array of Taub-NUT spaces. We use the explicit metric
on this geometry to derive the locally corrected warp factor and M-theory
three-from as closed expressions. We focus on contributions to the 7-brane
gauge coupling function from this M-theory back-reaction and show that terms
quadratic in the internal seven-brane flux are induced. The real part of the
gauge coupling function is modified by the M-theory warp factor while the
imaginary part is corrected due to a modified M-theory three-form potential.
The obtained contributions match the known weak string coupling result, but
also yield additional terms suppressed at weak coupling. This shows that the
completion of the M-theory reduction opens the way to compute various
corrections in a genuine F-theory setting away from the weak string coupling
limit.Comment: 46 page
Collider Implications of Kaluza-Klein Excitations of the Gluons
We consider an asymmetric string compactification scenario in which the SM
gauge bosons can propagate into one TeV-size extra compact dimension.
These gauge bosons have associated KK excitations that present additional
contributions to the SM processes. We calculate the effects that the KK
excitations of the gluons, 's, have on multijet final state
production in proton-proton collisions at the Large Hadron Collider energy. In
the case of dijet final states with very high , the KK signal due to
the exchanges of the 's is several factors greater than the SM
background for compactification scales as high as about 7 TeV. The
high- effect is not as dramatic for the direct production of a single
on-shell , which subsequently decays into - pairs, where
the KK signal significantly exceeds the SM three-jet background for
compactification scales up to about 3 TeV. We also present our results for the
four-jet final state signal from the direct production of two on-shell
's.Comment: 33 pages, LaTeX; added Figure 6 showing the dijet mass distribution
and corresponding discussion in a paragraph on page 11; some additionaal
discussions added; typos corrected; few references adde
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