899 resultados para critical exponents and amplitudes (experiment)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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The phase diagram of an asymmetric N = 3 Ashkin-Teller model is obtained by a numerical analysis which combines Monte Carlo renormalization group and reweighting techniques. Present results reveal several differences with those obtained by mean-field calculations and a Hamiltonian approach. In particular, we found Ising critical exponents along a line where Goldschmidt has located the Kosterlitz-Thouless multicritical point. On the other hand, we did find nonuniversal exponents along another transition line. Symmetry breaking in this case is very similar to the N = 2 case, since the symmetries associated to only two of the Ising variables are broken. However, for large values of the coupling constant ratio XW = W/K, when the only broken symmetry is of a hidden variable, we detected first-order phase transitions giving evidence supporting the existence of a multicritical point, as suggested by Goldschmidt, but in a different region of the phase diagram. © 2002 Elsevier Science B.V. All rights reserved.
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Pós-graduação em Física - IGCE
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The College of Arts and Sciences proudly presents the eighth issue of the Book of Abstracts, which highlights the work conducted by students in collaboration with faculty mentors. This collection of abstracts represents many hours of scholarly activity in which students further developed their research, critical thinking, and writing skills and engaged in learning well beyond the classroom.
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The College of Arts and Sciences proudly presents Undergraduate Scholarship in the College of Arts and Sciences Book of Abstracts, our ninth annual issue documenting the work conducted by students in collaboration with their faculty mentors. As you will see by the depth and variety of the projects, these students successfully used their research, critical thinking, and writing skills to produce scholarship that has been recognized by the larger scholarly community.
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The College of Arts and Sciences proudly presents the seventh Book of Abstracts, highlighting the undergraduate scholarship conducted by students in collaboration with faculty mentors. This collection of abstracts represents many hours of scholarly activity in which students further developed their research, critical thinking, and writing skills and engaged in learning well beyond the classroom. We congratulate the students and their faculty mentors for the quality of their work and their willingness to share it with the academic community through publications in refereed journals and presentations at regional, national, and international meetings. We also thank Evan Adams for editing the abstracts and Chris Richter, a visual communication design major, for designing the cover and producing the book.
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The College of Arts and Sciences proudly presents our fourth issue of Undergraduate Scholarship in the College of Arts and Sciences: Book of Abstracts, which highlights the work conducted by students in collaboration with faculty mentors. This collection of abstracts represents many hours of scholarly activity in which students further developed their research, critical thinking, and writing skills and engaged in learning well beyond the classroom.
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The College of Arts and Sciences proudly presents Undergraduate Scholarship in the College of Arts and Sciences, the third issue in our annual book of abstracts, containing the work conducted by students in collaboration with faculty mentors. As you will see by the depth and variety of the projects, these students successfully used their research, critical thinking, and writing skills to produce scholarship that has been recognized by the larger scholarly community. In fact, these collected works illustrate the students’ ability to communicate at a professional level; in many cases, these students have presented and defended their scholarship to the greater academic community at regional, national, and international meetings. We congratulate all the students and faculty mentors who are represented in this collection for their dedication to learning. This book is also the first designed and edited by Winthrop University undergraduate students. For their good work, we thank Kristen Jeffords for editing the abstracts, Paul Jones for creating the cover art, and Stephanie Sheldon for the book design and layout.
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Objective: Neuroimaging studies have highlighted important issues related to structural and functional brain changes found in sufferers of psychological trauma that may influence their ability to synthesize, categorize, and integrate traumatic memories. Methods: Literature review and critical analysis and synthesis. Results: Traumatic memories are diagnostic symptoms of post-traumatic stress disorder (PTSD), and the dual representation theory posits separate memory systems subserving vivid re-experiencing (non-hippocampally dependent) versus declarative autobiographical memories of trauma (hippocampally dependent). But the psychopathological signs of trauma are not static over time, nor is the expression of traumatic memories. Multiple memory systems are activated simultaneously and in parallel on various occasions. Neural circuitry interaction is a crucial aspect in the development of a psychotherapeutic approach that may favour an integrative translation of the sensory fragments of the traumatic memory into a declarative memory system. Conclusion: The relationship between neuroimaging findings and psychological approaches is discussed for greater efficacy in the treatment of psychologically traumatized patients.
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When a physical activity professional is teaching a motor skill, he evaluates the movement's learner and considers which interventions could be done at the moment. However, many times the instructor does not have such resources which could help him/her to evaluate the learner movement. The skill acquisition process could be facilitated if instructors could have an instrument that identifies errors, prioritizing information to be given to the learner. Considering that the specialized literature presents a lack of information about such tool, the purpose of this study was to develop, and to determine the objectivity and reliability of an instrument to assess the movement quality of the basketball free throw shooting. The checklist was developed and evaluated by basketball experts. Additionally, the checklist was used to assess 10 trials (edited video) from four individuals in different learning stages. Data were organized by the critical error and the error sum appointed by the experts in two different occasions (one week interval). Contrasting both evaluations, and also, contrasting different experts assessments, in sum and critical error, it was observed an average error of 16.9%. It was concluded that the checklist to assess the basketball free throw is reliable, and could help instructors to make a qualitative analysis. Moreover, the checklist may allow instructors to make assumptions on the motor learning process.
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Nickel oxide nonoparticles successfully synthesized by a polymer percursor method are studied in this work. The analysis of X-ray powder diffraction data provides a mean crystallite size of 22 +/- 2 nm which is in a good agreement with the mean size estimated from transmission electron microscopy images. Whereas the magnetization (M) vs. magnetic field (H) curve obtained at 5 K is consistent with a ferromagnetic component which coexists with an antiferromagnetic component, the presence of two peaks in the zero-field-cooled trace suggests the occurrence of two blocking process. The broad maximum at high temperature was associated with the thermal relaxation of uncompensated spins at the particle core and the low temperature peak was assigned to the freeze of surface spins clusters. Static and dynamic magnetic results suggest that the correlations of surface spins clusters show a spin-glass-like below T-g = 7.3 +/- 0.1 K with critical exponents zv = 9.7 +/- 0.5 and beta = 0.7 +/- 0.1, which are consistent with typical reported for spin-glass systems. (C) 2012 Elsevier B.V. All rights reserved.
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We have performed multicanonical simulations to study the critical behavior of the two-dimensional Ising model with dipole interactions. This study concerns the thermodynamic phase transitions in the range of the interaction delta where the phase characterized by striped configurations of width h = 1 is observed. Controversial results obtained from local update algorithms have been reported for this region, including the claimed existence of a second-order phase transition line that becomes first order above a tricritical point located somewhere between delta = 0.85 and 1. Our analysis relies on the complex partition function zeros obtained with high statistics from multicanonical simulations. Finite size scaling relations for the leading partition function zeros yield critical exponents. that are clearly consistent with a single second-order phase transition line, thus excluding such a tricritical point in that region of the phase diagram. This conclusion is further supported by analysis of the specific heat and susceptibility of the orientational order parameter.