9,813 research outputs found
How to trace and hear from doctoral alumni
Currently, in the UK we have knowledge about doctoral holders’ employability and destinations (“doctoral leavers”) from official HESA data. This source assures to know where PhDs bred in the UK work, provided they remain in the UK or go to work in the EU. There is still a dearth of knowledge about those who end to work outside the EU/UK. Among these latter target, arguably the Chinese nationals are the lion share. The statistical relevance of this target of doctoral leavers, and the still poor knowledge of doctoral employability, both concur to the necessity to shed more light in this phenomenon. We are working on building an original dataset from public repositories (Ethos British Library + ORCID) to understand career trajectories of people who got a PhD in the UK some 10 years ago. The final step of this project is sampling some of these leavers. We shall send them a pilot questionnaire to understand, retrospectively, the importance of having attained a PhD in the UK and the respective skills and abilities they developed during doctoral years and afterwards
Noise Rectification and Fluctuations of an Asymmetric Inelastic Piston
We consider a massive inelastic piston, whose opposite faces have different
coefficients of restitution, moving under the action of an infinitely dilute
gas of hard disks maintained at a fixed temperature. The dynamics of the piston
is Markovian and obeys a continuous Master Equation: however, the asymmetry of
restitution coefficients induces a violation of detailed balance and a net
drift of the piston, as in a Brownian ratchet. Numerical investigations of such
non-equilibrium stationary state show that the velocity fluctuations of the
piston are symmetric around the mean value only in the limit of large piston
mass, while they are strongly asymmetric in the opposite limit. Only taking
into account such an asymmetry, i.e. including a third parameter in addition to
the mean and the variance of the velocity distribution, it is possible to
obtain a satisfactory analytical prediction for the ratchet drift velocity.Comment: 6 pages, 5 figures, to be published on Europhysics Letters; some
references have been adde
Mullus argentinae, the Surmullet of southern South America
http://deepblue.lib.umich.edu/bitstream/2027.42/56747/1/OP308.pd
Which is the temperature of granular systems? A mean field model of free cooling inelastic mixtures
We consider a mean field model describing the free cooling process of a two
component granular mixture, a generalization of so called Maxwell model. The
cooling is viewed as an ordering process and the scaling behavior is attributed
to the presence of an attractive fixed point at for the dynamics. By
means of asymptotic analysis of the Boltzmann equation and of numerical
simulations we get the following results: 1)we establish the existence of two
different partial granular temperatures, one for each component, which violates
the Zeroth Law of Thermodynamics; 2) we obtain the scaling form of the two
distribution functions; 3) we prove the existence of a continuous spectrum of
exponents characterizing the inverse-power law decay of the tails of the
velocity, which generalizes the previously reported value 4 for the pure model;
4) we find that the exponents depend on the composition, masses and restitution
coefficients of the mixture; 5) we also remark that the reported distributions
represent a dynamical realization of those predicted by the Non Extensive
Statistical Mechanics, in spite of the fact that ours stem from a purely
dynamical approach.Comment: 23 pages, 9 figures. submitted for publicatio
TG/FT-IR: An Analysis of the Conditions Affecting the Combined TG/Spectral Response
The results of TG/FT-IR measurements performed on hydrated beta-cyclodextrin at different heating rates and with different carrier gas fluxes are reported. It is shown that the shape of the spectral curve and the its degree of matching with the DTG curves depend on both the TG heating rate and the carrier gas flow rate
Interface pinning and slow ordering kinetics on infinitely ramified fractal structures
We investigate the time dependent Ginzburg-Landau (TDGL) equation for a non
conserved order parameter on an infinitely ramified (deterministic) fractal
lattice employing two alternative methods: the auxiliary field approach and a
numerical method of integration of the equations of evolution. In the first
case the domain size evolves with time as , where is
the anomalous random walk exponent associated with the fractal and differs from
the normal value 2, which characterizes all Euclidean lattices. Such a power
law growth is identical to the one observed in the study of the spherical model
on the same lattice, but fails to describe the asymptotic behavior of the
numerical solutions of the TDGL equation for a scalar order parameter. In fact,
the simulations performed on a two dimensional Sierpinski Carpet indicate that,
after an initial stage dominated by a curvature reduction mechanism \`a la
Allen-Cahn, the system enters in a regime where the domain walls between
competing phases are pinned by lattice defects.
The lack of translational invariance determines a rough free energy
landscape, the existence of many metastable minima and the suppression of the
marginally stable modes, which in translationally invariant systems lead to
power law growth and self similar patterns. On fractal structures as the
temperature vanishes the evolution is frozen, since only thermally activated
processes can sustain the growth of pinned domains.Comment: 16 pages+14 figure
Velocity fluctuations in a one dimensional Inelastic Maxwell model
We consider the velocity fluctuations of a system of particles described by
the Inelastic Maxwell Model. The present work extends the methods, previously
employed to obtain the one-particle velocity distribution function, to the
study of the two particle correlations. Results regarding both the homogeneous
cooling process and the steady state driven regime are presented. In particular
we obtain the form of the pair correlation function in the scaling region of
the homogeneous cooling process and show that some of its moments diverge. This
fact has repercussions on the behavior of the energy fluctuations of the model.Comment: 16 pages, 1 figure, to be published on Journal of Statistical
Mechanics: Theory and Experiment
Anisotropic excitonic effects in the energy loss function of hexagonal boron nitride
We demonstrate that the valence energy-loss function of hexagonal boron
nitride (hBN) displays a strong anisotropy in shape, excitation energy and
dispersion for momentum transfer q parallel or perpendicular to the hBN layers.
This is manifested by e.g. an energy shift of 0.7 eV that cannot be captured by
single-particle approaches and is a demonstration of a strong anisotropy in the
two-body electron-hole interaction. Furthermore, for in-plane directions of q
we observe a splitting of the -plasmon in the M direction that is absent in the
K direction and this can be traced back to band-structure effects.Comment: 10 pages, 4 figure
Upaya Peningkatan Hasil Belajar Pengukuran Waktu Melalui Media Jam Pintar Pada Siswa Kelas Iii-a Sdn Tlogomas 2 Kota Malang
Proses pembelajaran tanpa media yang konkret akan mengakibatkan siswa kesulitan untuk memahami suatu konsep sehingga media konkret sangat dibutuhkan dalam proses pembelajaran agar siswa lebih mudah memahami konsep. Selain itu, pemilihan media juga perlu dipertimbangkan. Pemilihan media yang tepat akan meningkat hasil belajar siswa dan membuat siswa lebih fokus selama proses pembelajaran. Penelitian ini membahas penggunaan Jam Pintar sebagai salah satu media konkret yang dapat digunakan sebagai upaya peningkatan hasil belajar siswa tentang pengukuran waktu. Penelitian ini menunjukkan penerapan Jam Pintar dpat meningkatkan hasil belajar siswa kelas III-A SDN Tlogomas 2 Kota Malang yang pada tahap pra siklus 16,6%, meningkat menjadi 56,6% pada siklus I dan meningkat menjadi 83,3% pada siklus II
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