9,803 research outputs found
Parallel hybrid textures of lepton mass matrices
We analyse the parallel hybrid texture structures in the charged lepton and
the neutrino sector. These parallel hybrid texture structures have physical
implications as they cannot be obtained from arbitrary lepton mass matrices
through weak basis transformations. The total sixty parallel hybrid texture
structures can be grouped into twelve classes, and all the hybrid textures in
the same class have identical physical implications. We examine all the twelve
classes under the assumption of non-factorizable phases in the neutrino mass
matrix. Five out of the total twelve classes are found to be phenomenologically
disallowed. We study the phenomenological implications of the allowed classes
for 1-3 mixing angle, Majorana and Dirac-type violating phases.
Interesting constraints on effective Majorana mass are obtained for all the
allowed classes.Comment: Physical Review D (To appear
The eigenspectra of Indian musical drums
In a family of drums used in the Indian subcontinent, the circular drum head
is made of material of non-uniform density. Remarkably, and in contrast to a
circular membrane of uniform density, the low eigenmodes of the non-uniform
membrane are harmonic. In this work we model the drum head by a non-uniform
membrane whose density varies smoothly between two prescribed values. Using a
Fourier-Chebyshev spectral collocation method we obtain the eigenmodes and
eigenvalues of the drum head. For a suitable choice of parameters, which we
find by optimising a cost function, the eigenspectra obtained from our model
are in excellent agreement with experimental values. Our model and the
numerical method should find application in numerical sound synthesis
Effects of physical activity on debilitating behaviours in 13- to 20-year-old males with severe autism spectrum disorder
The presented study investigated the extent to which engaging in a therapeutic sporting programme in males with severe Autism Spectrum Disorder (ASD) improves the debilitating behaviours commonly associated with ASD. Furthermore, the views of parents of the autistic participants were assessed concerning the effectiveness of the programme. Participants were eight 13-20 year old males born in the UK from a school and sports college for pupils with severe learning difficulties. The selection was using volunteer sampling from the “Monday Club” initiative, run by Saracens Sports Foundation in partnership with a local School and specialist Sports College. The Gilliam Autism Rating Scale (GARS-3) was administered to identify and measure the severity of ASD behaviours at four time periods namely: at programme entry as the baseline (T1), a second time after 8 weeks (T2), a third time after sixteen weeks (T3) and a fourth time post programme (T4). The results showed that for the more severe cases of ASD (Autism Index >101) there was no positive change in subscale performance from Time1 to Time2. For milder cases (Autism Index 71-100) there were subtle non-significant improvements on the subscale scores from Time1 to Time2. Of the 6 subscales at Time2, Emotional Responses (ER), Cognitive Style (CS) and Maladaptive Speech (MS) approached significance at the p = 0.05 level. At Time3 and Time4, there was also no statistically significant improvement in ASD behaviours compared to the baseline for either condition. Finally parents’ were “very satisfied” with their child’s participation in the physical activity programme
Quantum and Classical Dynamics of a BEC in a Large-Period Optical Lattice
We experimentally investigate diffraction of a Rb-87 Bose-Einstein condensate
from a 1D optical lattice. We use a range of lattice periods and timescales,
including those beyond the Raman-Nath limit. We compare the results to quantum
mechanical and classical simulations, with quantitative and qualitative
agreement, respectively. The classical simulation predicts that the envelope of
the time-evolving diffraction pattern is shaped by caustics: singularities in
the phase space density of classical trajectories. This behavior becomes
increasingly clear as the lattice period grows.Comment: 7 pages, 6 figure
Vitamin changes in sweets with time and storage conditions
Vitamin changes assocd. with different temp. and period of storage were measured in sweets rasmalai and badam pista roll. A comparative study was done between these sweets from two different sweet marts. With std. colorimetric techniques the anal. was carried out and by applying statistical methods the variations were tabulated. The vitamin content (niacin and ascorbic acid) decreased with increase in temp. and storage period in accordance with moisture and pH
Hydrogeologisch matematisch model van het Nederlands-Belgisch grensgebied in de omgeving van de Kalmthoutse heide
Selection from read-only memory with limited workspace
Given an unordered array of elements drawn from a totally ordered set and
an integer in the range from to , in the classic selection problem
the task is to find the -th smallest element in the array. We study the
complexity of this problem in the space-restricted random-access model: The
input array is stored on read-only memory, and the algorithm has access to a
limited amount of workspace. We prove that the linear-time prune-and-search
algorithm---presented in most textbooks on algorithms---can be modified to use
bits instead of words of extra space. Prior to our
work, the best known algorithm by Frederickson could perform the task with
bits of extra space in time. Our result separates
the space-restricted random-access model and the multi-pass streaming model,
since we can surpass the lower bound known for the latter
model. We also generalize our algorithm for the case when the size of the
workspace is bits, where . The running time
of our generalized algorithm is ,
slightly improving over the
bound of Frederickson's algorithm. To obtain the improvements mentioned above,
we developed a new data structure, called the wavelet stack, that we use for
repeated pruning. We expect the wavelet stack to be a useful tool in other
applications as well.Comment: 16 pages, 1 figure, Preliminary version appeared in COCOON-201
Biot-Savart correlations in layered superconductors
We discuss the superconductor to normal phase transition in an
infinite-layered type-II superconductor in the limit where the Josephson
coupling between layers is negligible. We model each layer as a neutral gas of
thermally excited pancake vortices. We assume the dominant interaction between
vortices in the same and in different layers is the electromagnetic interaction
between the screening currents induced by these vortices. Our main result,
obtained by exactly solving the leading order renormalization group flow, is
that the phase transition in this model is a Kosterlitz--Thouless transition
despite being a three--dimensional system. While the transition itself is
driven by the unbinding of two-dimensional pancake vortices, an RG analysis of
the low temperature phase and a mean-field theory of the high temperature phase
reveal that both phases possess three-dimensional correlations. An experimental
consequence of this is that the jump in the measured in-plane superfluid
stiffness, which is a universal quantity in 2d Kosterlitz-Thouless theory, will
receive a small non--universal correction (of order 1% in
BiSrCaCuO). This overall picture places some claims
expressed in the literature on a more secure analytical footing and also
resolves some conflicting views.Comment: 16 pages, 2 figures; minor typos corrected, references adde
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