Lanczos exact diagonalization study of field-induced phase transition for Ising and Heisenberg antiferromagnets

Using an exact diagonalization treatment of Ising and Heisenberg model Hamiltonians, we study field-induced phase transition for two-dimensional antiferromagnets. For the system of Ising antiferromagnet the predicted field-induced phase transition is of first order, while for the system of Heisenberg antiferromagnet it is the second-order transition. We find from the exact diagonalization calculations that the second-order phase transition (metamagnetism) occurs through a spin-flop process as an intermediate step.Comment: 4 pages, 4 figure

O PIBID de li como ferramenta para a melhora da oralidade: relato de uma intervenção

Anais do II Seminário Seminário Estadual PIBID do Paraná: tecendo saberes / organizado por Dulcyene Maria Ribeiro e Catarina Costa Fernandes — Foz do Iguaçu: Unioeste; Unila, 2014O presente trabalho tem como objetivo apresentar uma sequência didática desenvolvida pelos alunos do Programa Institucional de bolsas à iniciação à docência de uma universidade estadual localizada no norte do Paraná no 9o ano de um colégio da rede básica de ensino, nível ensino médio. Com a finalidade de antecipar o vínculo entre futuros professores e a sala de aula da rede pública bem como tornar o ensino mais efetivo e prazeroso, desenvolvemos em nossa sequência a oralidade por meio do gênero música, uma vez que é um gênero presente no cotidiano do nosso público alvo. A partir do exposto e com base no referencial teórico do Interacionismo Sociodiscursivo (BRONCKART, 2009) e da sequência didática a (DOLZ, NOVERRAZ, SCHNEWLY, 2004) contribuímos com a ampliação do vocabulário, aperfeiçoamento da pronúncia, além de outras aptidões específica

Mixing of Ground States in Vertex Models

We consider the analogue of the 6-vertex model constructed from alternating spin n/2 and spin m/2 lines, where $1\leq n<m$. We identify the transfer matrix and the space on which it acts in terms of the representation theory of $U_q(sl_2)$. We diagonalise the transfer matrix and compute the S-matrix. We give a trace formula for local correlation functions. When n=1, the 1-point function of a spin m/2 local variable for the alternating lattice with a particular ground state is given as a linear combination of the 1-point functions of the pure spin m/2 model with different ground states. The mixing ratios are calculated exactly and are expressed in terms of irreducible characters of $U_q(sl_2)$ and the deformed Virasoro algebra.Comment: 12 pages, LaTeX, typos correcte

Supersymmetric quantum mechanics with nonlocal potentials

We consider supersymmetric quantum mechanical models with both local and nonlocal potentials. We present a nonlocal deformation of exactly solvable local models. Its energy eigenfunctions and eigenvalues are determined exactly. We observe that both our model Hamiltonian and its supersymmetric partner may have normalizable zero-energy ground states, in contrast to local models with nonperiodic or periodic potentials.Comment: 4 pages, REVTeX, Minor revisions for clarificatio

Maxwell Chern-Simons Solitons from Type IIB String Theory

We study various three-dimensional supersymmetric Maxwell Chern-Simons solitons by using type IIB brane configurations. We give a systematic classification of soliton spectra such as topological BPS vortices and nontopological vortices in $\mathcal{N}=2,3$ supersymmetric Maxwell Chern-Simons system via the branes of type IIB string theory. We identify the brane configurations with the soliton spectra of the field theory and obtain a nice agreement with field theory aspects. We also discuss possible brane constructions for BPS domain wall solutions.Comment: 23 pages, Latex, 4 figures; (q_1,q_2)-string convention changed, minor correction

Do differences in profiling criteria bias performance measurements? Economic profiling of medical clinics under the Korea National Health Insurance program: An observational study using claims data

<p>Abstract</p> <p>Background</p> <p>With a greater emphasis on cost containment in many health care systems, it has become common to evaluate each physician's relative resource use. This study explored the major factors that influence the economic performance rankings of medical clinics in the Korea National Health Insurance (NHI) program by assessing the consistency between cost-efficiency indices constructed using different profiling criteria.</p> <p>Methods</p> <p>Data on medical care benefit costs for outpatient care at medical clinics nationwide were collected from the NHI claims database. We calculated eight types of cost-efficiency index with different profiling criteria for each medical clinic and investigated the agreement between the decile rankings of each index pair using the weighted kappa statistic.</p> <p>Results</p> <p>The exclusion of pharmacy cost lowered agreement between rankings to the lowest level, and differences in case-mix classification also lowered agreement considerably.</p> <p>Conclusions</p> <p>A medical clinic may be identified as either cost-efficient or cost-inefficient, even when using the same index, depending on the profiling criteria applied. Whether a country has a single insurance or a multiple-insurer system, it is very important to have standardized profiling criteria for the consolidated management of health care costs.</p

Defining the optimal dose of radiation in leukemic patients with extramedullary lesions

<p>Abstract</p> <p>Background</p> <p>Analysis of the clinical response of extramedullary lesions in leukemic patients treated with radiation therapy (RT) and defining the optimal dose of radiation.</p> <p>Methods</p> <p>Forty-two extramedullary lesions found in 24 leukemic patients treated with RT were reviewed. The radiation was delivered usually 2 Gy/day, up to a median of 20 Gy (range: 18.0-40.8). The clinical response and symptom palliation effect were analyzed. The factors affecting the response were also included in the analysis.</p> <p>Results</p> <p>After a median time of 7.9 weeks, the overall response rate was 76.2%. A complete response (CR) was achieved in 35.7%, a partial response in 40.5%. The symptom was relieved in 85.7% sites. The overall response rate was better in patients whose initial tumor size was smaller than 10 cm²(<it>p = 0.010</it>) or who were treated with more than 25 Gy (<it>p = 0.031</it>). The overall CR rate was also higher in those who had smaller tumors (smaller than 6 cm or 30 cm²) (<it>p = 0.015)</it>, or when the tumor was located in soft tissue (<it>p = 0.029</it>).</p> <p>Conclusions</p> <p>Extramedullary lesions in leukemic patients can be successfully treated with RT. The tumor response rate was excellent and symptom relief was achieved in almost all patients. There was a better response to treatment when the tumor was small or it was located in soft tissue. Although, there was no definite correlation between volume reduction and total dose, it seems that higher total dose more of than 25 Gy is needed for better response.</p