54,801 research outputs found
The effects of Peru's push to improve education
From the mid-1950s to the 1960s, the Government of Peru undertook a major expansion of public education, increasing the number of schools, requiring primary schools that offered an incomplete cycle to add grades, and increasing school inputs (principally teachers and textbooks). The paper examines the effects of Peru's educational policies, and the effects of family background and community characteristics on the schooling levels of a number of adults. Data on males and females were analyzed seperately by birth cohort.Teaching and Learning,Primary Education,Gender and Education,Health Monitoring&Evaluation,Education Reform and Management
Dielectric molding apparatus Patent
Dielectric apparatus for heating, fusing, and hardening of organic matrix to form plastic material into shaped produc
Model for the unidirectional motion of a dynein molecule
Cytoplasmic dyneins transport cellular organelles by moving on a microtubule
filament. It has been found recently that depending on the applied force and
the concentration of the adenosine triphosphate (ATP) molecules, dynein's step
size varies. Based on these studies, we propose a simple model for dynein's
unidirectional motion taking into account the variations in its step size. We
study how the average velocity and the relative dispersion in the displacement
vary with the applied load. The model is amenable to further extensions by
inclusion of details associated with the structure and the processivity of the
molecule.Comment: 10 pages, 5 figure
Spectral evidence for carbonates on Mars: Hydrous carbonates
Although many of the spectral features of the Martian samples studied are not unique mineralogical indicators, much of the current spectral data is consistent with (possibly abundant) hydrous carbonates on the surface of Mars. The absorption features in the measured samples were quite weak compared with those of anhydrous carbonates. The weak features imply that significantly more hydrous carbonates can be incorporated onto the surface before becoming spectrally evident; however, exact limits have yet to be determined. The stability of these materials in the Martian environment is not known, but their formation and occurrence in low temperature terrestrial environments makes them appealing candidates for weathering products on Mars
High Redshift Standard Candles: Predicted Cosmological Constraints
We investigate whether future measurements of high redshift standard candles
(HzSCs) will be a powerful probe of dark energy, when compared to other types
of planned dark energy measurements. Active galactic nuclei and gamma ray
bursts have both been proposed as potential HzSC candidates. Due to their high
luminosity, they can be used to probe unexplored regions in the expansion
history of the universe. Information from these regions can help constrain the
properties of dark energy, and in particular, whether it varies over time.
We consider both linear and piecewise parameterizations of the dark energy
equation of state, , and assess the optimal redshift distribution a
high-redshift standard-candle survey could take to constrain these models.
The more general the form of the dark energy equation of state being
tested, the more useful high-redshift standard candles become. For a linear
parameterization of , HzSCs give only small improvements over planned
supernova and baryon acoustic oscillation measurements; a wide redshift range
with many low redshift points is optimal to constrain this linear model.
However to constrain a general, and thus potentially more informative, form of
, having many HzSCs can significantly improve limits on the nature of
dark energy.Comment: Accepted MNRAS, 27 Pages, 15 figures, matches published versio
Development of a mechatronic sorting system for removing contaminants from wool
Automated visual inspection (AVI) systems have been
extended to many fields, such as agriculture and the food, plastic
and textile industries. Generally, most visual systems only inspect
product defects, and then analyze and grade them due to the lack
of any sorting function. This main reason rests with the difficulty of
using the image data in real time. However, it is increasingly important
to either sort good products from bad or grade products into
separate groups usingAVI systems. This article describes the development
of a mechatronic sorting system and its integration with a
vision system for automatically removing contaminants from wool
in real time. The integration is implemented by a personal computer,
which continuously processes live images under the Windows
2000 operating system. The developed real-time sorting approach
is also applicable to many other AVI systems
Revealing the Archetype: The Journey of a Trecento Madonna and Child at the National Museum of Scotland
The National Museums Scotland Madonna and
Child project sought to uncover and document
the history of a fine polychrome wood carving
attributed to The Master of the Gualino St
Catherine and to prepare it for display. A new
body of knowledge has been assembled by
the interdisciplinary team. The conservation
treatment was informed by this work and led
to further discoveries: the removal of overpaint
exposing a previously hidden underdrawing.
The ethics of the treatment decisions, including
the removal of the Christ Child’s 1960s’ fingers required team dialogue and was opened up for
the public to respond to in a series of blogs.
The discovery of a rich polychromy including
gold and glazed tin has led to further plans to
produce a 3-D colour reconstruction. The collaborations
developed during this project will
facilitate future joint ventures for polychrome
sculpture in Scottish collections
New spectral observations of Callisto and leading/trailing hemisphere distinctions
In December 1989 and January 1990, new observations of the leading and trailing edges of Callisto were made from the NASA Infrared Telescope Facility on Mauna Kea in Hawaii. Using the Cool Grating Array Spectrometer, spectral coverage was obtained from 1.89 to 2.46 microns and from 2.8 to 4.2 microns for both the leading and trailing hemispheres. In addition, spectral coverage of the leading hemisphere was obtained from 1.30 to 2.55 microns and from 4.2 to 4.8 microns. Interpretations of the data are given
On character generators for simple Lie algebras
We study character generating functions (character generators) of simple Lie
algebras. The expression due to Patera and Sharp, derived from the Weyl
character formula, is first reviewed. A new general formula is then found. It
makes clear the distinct roles of ``outside'' and ``inside'' elements of the
integrity basis, and helps determine their quadratic incompatibilities. We
review, analyze and extend the results obtained by Gaskell using the Demazure
character formulas. We find that the fundamental generalized-poset graphs
underlying the character generators can be deduced from such calculations.
These graphs, introduced by Baclawski and Towber, can be simplified for the
purposes of constructing the character generator. The generating functions can
be written easily using the simplified versions, and associated Demazure
expressions. The rank-two algebras are treated in detail, but we believe our
results are indicative of those for general simple Lie algebras.Comment: 50 pages, 11 figure
String-Inspired Triplet See-Saw from Diagonal Embedding of SU(2)_L in SU(2)_A x SU(2)_B
Motivated by string constructions, we consider a variant on the Type II
see-saw mechanism involving the exchange of triplet representations of SU(2)_L
in which this group arises from a diagonal embedding into SU(2)_A x SU(2)_B. A
natural assignment of Standard Model lepton doublets to the two underlying
gauge groups results in a bimaximal pattern of neutrino mixings and an inverted
hierarchy in masses. Simple perturbations around this leading-order structure
can accommodate the observed pattern of neutrino masses and mixings.Comment: 8 pages; uses RevTe
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