18,302 research outputs found
Phase Transitions for Belousov-Zhabotinsky Reactions
The main objective of this article is to study the dynamic phase transitions
associated with the spatial-temporal oscillations of the BZ reactions, given by
Field, Koros and Noyes, also referred as the Oregonator. Two criteria are
derived to determine 1) existence of either multiple equilibria or
spatiotemporal oscillations, and 2) the types of transitions. These criteria
gives a complete characterization of the dynamic transitions of the BZ systems
from the homogeneous states. The analysis is carried out using a dynamic
transition theory developed recently by the authors, which has been
successfully applied to a number of problems in science
AN ILLUMINATIVE EVALUATION OF ARABIC LANGUAGE AND ISLAMIC VALUES EDUCATION (ALIVE) PROGRAM IN THE PHILIPPINES: THE CASE OF FIVE (5) ELEMENTARY SCHOOLS IN THREE CITIES
The study examined the Arabic Language and Islamic Values Education (ALIVE) Program in the Philippines through the lens of illuminative evaluation. The topic was born out of the researcher’s interest in Islam and its believers. In 2005, in its desire to promote better relations between the Philippine government and Muslim Filipinos, the Philippine government through the Department of Education launched ALIVE. Almost 14 years in the public school system, the curriculum/program has been studied and evaluated but by a limited number of individuals and institutions only. Moreover, evaluations of ALIVE often looked at the actual conduct of the program/curriculum, usually focused on the instructional system such as teachers and the facilities. The researcher felt that this focus was not broad enough to shed light on the actual implementation of the program. Through illuminative evaluation approach which considers both the instructional system and the learning milieu as the main elements that can affect a program, the researcher found a means to better study the program.
The study involved five (5) public elementary schools located in the cities of Manila, Sta. Rosa, and Baguio. Data gathering in the form of several observations and interviews were conducted in November 2017-February 2018. In the study, it was established that the success or failure of ALIVE’s implementation lies primarily on the dedication and effectiveness of the ALIVE Ustadz, leadership of the principal, and the mobilized community support given to the program. The last two factors were significantly influenced by their knowledge and understanding of Islam and Muslims which in turn affect their views on the program. Almost 15 years as a program in public schools, ALIVE is still replete with challenges from the instructional system and learning milieu that can be remedied or solved if the school leadership and the DepEd wish to
Carbon-fiber tips for scanning probe microscopes and molecular electronics experiments
We fabricate and characterize carbon-fiber tips for their use in combined
scanning tunneling and force microscopy based on piezoelectric quartz tuning
fork force sensors. An electrochemical fabrication procedure to etch the tips
is used to yield reproducible sub-100-nm apex. We also study electron transport
through single-molecule junctions formed by a single octanethiol molecule
bonded by the thiol anchoring group to a gold electrode and linked to a carbon
tip by the methyl group. We observe the presence of conductance plateaus during
the stretching of the molecular bridge, which is the signature of the formation
of a molecular junction.Comment: Conference Proceeding (Trends in NanoTechnology 2011, Tenerife
SPAIN); Nanoscale Research Letters, (2012) 7:25
The diverse evolutionary paths of simulated high-z massive, compact galaxies to z=0
Massive quiescent galaxies have much smaller physical sizes at high redshift
than today. The strong evolution of galaxy size may be caused by progenitor
bias, major and minor mergers, adiabatic expansion, and/or renewed star
formation, but it is difficult to test these theories observationally. Herein,
we select a sample of 35 massive, compact galaxies (
M, M/kpc) at in the
cosmological hydrodynamical simulation Illustris and trace them forward to
to uncover their evolution and identify their descendants. By , the
original factor of 3 difference in stellar mass spreads to a factor of 20. The
dark matter halo masses similarly spread from a factor of 5 to 40. The
galaxies' evolutionary paths are diverse: about half acquire an ex-situ
envelope and are the core of a more massive descendant, a third survive
undisturbed and gain very little mass, 15% are consumed in a merger with a more
massive galaxy, and a small remainder are thoroughly mixed by major mergers.
The galaxies grow in size as well as mass, and only 10% remain compact by
. The majority of the size growth is driven by the acquisition of ex-situ
mass. The most massive galaxies at are the most likely to have compact
progenitors, but this trend possesses significant dispersion which precludes a
direct linkage to compact galaxies at . The compact galaxies' merger rates
are influenced by their environments, so that isolated or satellite
compact galaxies (which are protected from mergers) are the most likely to
survive to the present day.Comment: 19 pages, 10 figures, MNRAS accepted version including 2 new figure
Analysis of Highly Directive Cavity-Type Configurations Comprising of Low Profile Antennas Covered by Superstrates
In this paper we present a technique for designing antenna/superstrate composites to produce enhanced directivities. As a first step, we study the underlying mechanism that governs the performance of theses antennas by studying the canonical problem of a line source in a rectangular waveguide. The above problem is solved by constructing the Green’s function corresponding to the line source in the rectangular guide, one of whose walls is partially reflecting, that is can leak electromagnetic energy into the space external to the guide. The Green’s function for this problem can be constructed by aggregating the multiple reflections from the two walls. Although the above model is only two-dimensional, we show that it can be used to predict the performance of antenna/superstrate composites. We demonstrate this by modeling several highly directive antennas and show that indeed the required characteristics of this type of antennas can be determined from the analysis of the cutoff behavior of the rectangular guide
Neutrino mixing and CP-violation
The prospects of measuring the leptonic angles and CP-odd phases at a
neutrino factory are discussed in two scenarios: 1) three active neutrinos as
indicated by the present ensemble of atmospheric plus solar data; 2) three
active plus one sterile neutrino when the LSND signal is also taken into
account. For the latter we develop one and two mass dominance approximations.
The appearance of wrong sign muons in long baseline experiments and tau leptons
in short baseline ones provides the best tests of CP-violation in scenarios 1)
and 2), respectively.Comment: 22 pages, LaTeX2e, 17 eps files, use package epsfi
Four species neutrino oscillations at -Factory: sensitivity and CP-violation
The prospects of measuring the leptonic angles and CP-odd phases at a {\em
neutrino factory} are discussed in the scenario of three active plus one
sterile neutrino. We consider the \nu_\mu \raw \nu_e LSND signal. Its
associated large mass difference leads to observable neutrino oscillations at
short ( km) baseline experiments. Sensitivities to the leptonic angles
down to can be easily achieved with a 1 Ton detector. Longer baseline
experiments ( km) with a 1 Kton detector can provide very clean tests
of CP-violation especially through tau lepton detection.Comment: 15 pages, LaTeX2e, 14 eps files, use package epsfi
Language-Grounded Control for Coordinated Robot Motion and Speech
Recent advancements have enabled human-robot collaboration through physical
assistance and verbal guidance. However, limitations persist in coordinating
robots' physical motions and speech in response to real-time changes in human
behavior during collaborative contact tasks. We first derive principles from
analyzing physical therapists' movements and speech during patient exercises.
These principles are translated into control objectives to: 1) guide users
through trajectories, 2) control motion and speech pace to align completion
times with varying user cooperation, and 3) dynamically paraphrase speech along
the trajectory. We then propose a Language Controller that synchronizes motion
and speech, modulating both based on user cooperation. Experiments with 12
users show the Language Controller successfully aligns motion and speech
compared to baselines. This provides a framework for fluent human-robot
collaboration.Comment: Under review in ICRA 202
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