1,459 research outputs found
-odometers and their almost 1-1 extensions
In this paper we recall the concepts of -odometer and -subodometer for
-actions, where is a discrete finitely generated group, which generalize
the notion of odometer in the case G=\ZZ. We characterize the -regularly
recurrent systems as the minimal almost 1-1 extensions of subodometers, from
which we deduce that the family of the -Toeplitz subshifts coincides with
the family of the minimal symbolic almost 1-1 extensions of subodometers.Comment: 18 page
Pipe joints reinforced in place with fitted aluminum sleeves
Installation of an aluminum sleeve, using specially designed tools, reinforces solder- sealed ferrule joints in installed small-diameter aluminum tubing. Tubing joints reinforced by this method withstand considerable torsional tensional, and vibrational stresses at moderately elevated temperatures
Importance of Grief and Loss Support
The capstone was implemented at the Safety Nest, a wellness center that provides socio-emotional and mental health services to all students within Everett Alvarez High School through the Positive Behavioral Interventions and Supports multi-tiered system. The school serves 2,664 students; 90.2% of Hispanic/Latino ethnicity, and it is part of the Salinas Union High School District. The social problem addressed by the project is that “There are too many high school students in California experiencing emotional distress, which can result in academic failure, substance use, or suicide”. The project consisted of collaborating with the NEST’s Behavioral Intervention Specialist to implement an eight-week long Grief/Loss Counseling group for EAHS students who have experienced a recent death/loss of a loved one. The group provides a safe space to support students experiencing grief/bereavement, learn about grief, coping skills, and how to express their emotions in healthy/constructive ways in order for the healing process to begin. The positive experience from the groups suggests the NEST continues to facilitate the Grief/Loss Counseling group through the practice of Ligia M. Houben’s book, “Counseling Hispanics Through Loss, Grief, and Bereavement: A guide for mental health professionals.
Quantum Gowdy Model: Schrodinger Representation with Unitary Dynamics
The linearly polarized Gowdy model is paradigmatic for studying
technical and conceptual issues in the quest for a quantum theory of gravity
since, after a suitable and almost complete gauge fixing, it becomes an exactly
soluble midisuperspace model. Recently, a new quantization of the model,
possessing desired features such as a unitary implementation of the gauge group
and of the time evolution, has been put forward and proven to be essentially
unique. An appropriate setting for making contact with other approaches to
canonical quantum gravity is provided by the Schr\"odinger representation,
where states are functionals on the configuration space of the theory. Here we
construct this functional description, analyze the time evolution in this
context and show that it is also unitary when restricted to physical states,
i.e. states which are solutions to the remaining constraint of the theory.Comment: 21 pages, version accepted for publication in Physical Review
Determination of biosorption mechanism in biomass of agave, using spectroscopic and microscopic techniques for the purification of contaminated water
[Abstract] Lead (Pb2+) and copper (Cu2+) are polluting metals due to their toxicity; however, the extraction of these metals is essential for economic development, so it is important to look for efficient and low-cost alternatives that can remove heavy metals from the various bodies of water. One of the alternatives used in this work is biosorption, for which an agroindustrial waste (epidermis from Agave atrovirens) was used to evaluate the affinity of removal of lead and copper in aqueous solutions; in addition, spectroscopy and microscopy techniques were used to elucidate and corroborate the removal and affinity capacity of the agave epidermis for both metals studied. The optimal pH value for the removal of both metals was 3. The adsorption isotherms yielded a qmax of 25.7 and 8.6 mg/g for lead and copper, respectively. Adjusting to the Langmuir-Freundlich model, the adsorption kinetics were pseudo-second order, and it was found that the equilibrium time was at 140 min. The spectroscopy and microscopy analyses corroborated the affinity between metals and functional groups of the agave, as well as with the elemental analysis, which reported 17.38% of lead and 4.25% of copper.[Resumen] El plomo (Pb2+) y el cobre (Cu2+) son metales contaminantes debido a su toxicidad; sin embargo, la extracciĂłn de estos metales es indispensable para el desarrollo econĂłmico, por lo que es importante buscar alternativas eficientes y de bajo costo que puedan remover metales pesados de los diversos cuerpos de agua. Una de las alternativas utilizadas en este trabajo es la biosorciĂłn, para la cual se utilizĂł un residuo agroindustrial (epidermis de Agave atrovirens), para evaluar la afinidad de remociĂłn del plomo y cobre en soluciones acuosas; adicionalmente, se emplearon tĂ©cnicas de espesctroscopĂa y microscopĂa que permitieron elucidar y corroborar la capacidad de remociĂłn y afinidad que tuvo la epidermis de A. atrovirens para ambos metales estudiados. El valor Ăłptimo de pH para la remociĂłn de ambos metales fue 3. Las isotermas de adsorciĂłn arrojaron una qmax de 25.7 y 8.6 mg/g para el plomo y cobre, respectivamente. Ajustando al modelo de Langmuir-Freundlich, las cinĂ©ticas de adsorciĂłn resultaron de pseudo-segundo orden, se encontrĂł que el tiempo de equilibrio es a los 140 min. El análisis espectroscĂłpico y microscĂłpico, corroborĂł la afinidad entre metales y grupos funcionales del agave, asĂ como con el análisis elemental, el cual reportĂł 17.38% de plomo y 4.25% de cobre
Fock quantization of a scalar field with time dependent mass on the three-sphere: unitarity and uniqueness
We study the Fock description of a quantum free field on the three-sphere
with a mass that depends explicitly on time, also interpretable as an
explicitly time dependent quadratic potential. We show that, under quite mild
restrictions on the time dependence of the mass, the specific Fock
representation of the canonical commutation relations which is naturally
associated with a massless free field provides a unitary dynamics even when the
time varying mass is present. Moreover, we demonstrate that this Fock
representation is the only acceptable one, up to unitary equivalence, if the
vacuum has to be SO(4)-invariant (i.e., invariant under the symmetries of the
field equation) and the dynamics is required to be unitary. In particular, the
analysis and uniqueness of the quantization can be applied to the treatment of
cosmological perturbations around Friedmann-Robertson-Walker spacetimes with
the spatial topology of the three-sphere, like e.g. for gravitational waves
(tensor perturbations). In addition, we analyze the extension of our results to
free fields with a time dependent mass defined on other compact spatial
manifolds. We prove the uniqueness of the Fock representation in the case of a
two-sphere as well, and discuss the case of a three-torus.Comment: 30 page
Regression with Linear Factored Functions
Many applications that use empirically estimated functions face a curse of
dimensionality, because the integrals over most function classes must be
approximated by sampling. This paper introduces a novel regression-algorithm
that learns linear factored functions (LFF). This class of functions has
structural properties that allow to analytically solve certain integrals and to
calculate point-wise products. Applications like belief propagation and
reinforcement learning can exploit these properties to break the curse and
speed up computation. We derive a regularized greedy optimization scheme, that
learns factored basis functions during training. The novel regression algorithm
performs competitively to Gaussian processes on benchmark tasks, and the
learned LFF functions are with 4-9 factored basis functions on average very
compact.Comment: Under review as conference paper at ECML/PKDD 201
Modelling of Surfaces of Engineering Products on the Basis of Array of Points
The method of designing elements of the surfaces\u27 frames based on array of points is suggested in the work. Elements of frames are contours that are received via interpolation of sets of points, which are selected from the initial array of points. The algorithms have been developed for design plane and spatial contours that represent the curves with specified geometrical properties with prescribed accuracy. Formed contours are used as elements of «Profile» and «Guide Curves» at forming the model of surface by means of function of «Lofted Surface» in CAD system. Using the method of designing elements of frames of the surfaces is actual for modeling of surfaces of technical items that function-interact with the environment. The developed method was proven while modelling functional surfaces that bound an impeller blade channel of a turbine compressor
Learning Disabilities in Children with Autism
Children with autism spectrum disorders often present signs of cognitive strategies that are not within the expected developmental profile. Therefore, it should be expected that the learning process of children with this disorder should be the focus of several studies regarding schooling and literacy. Unfortunately, that is not the real situation. In this chapter, the authors propose to present an overview of the available literature about learning, reading, and literacy in children with the autism spectrum disorders and report results of studies about the association between executive functions and reading abilities in children with autism spectrum disorders that attend to regular and special schools in Brazil
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