521 research outputs found

    Flavor-Dependence and Higher Orders of Gauge-Independent Solutions in Strong Coupling Gauge Theory

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    The fermion flavor NfN_f dependence of non-perturbative solutions in the strong coupling phase of the gauge theory is reexamined based on the interrelation between the inversion method and the Schwinger-Dyson equation approach. Especially we point out that the apparent discrepancy on the value of the critical coupling in QED will be resolved by taking into account the higher order corrections which inevitably lead to the flavor-dependence. In the quenched QED, we conclude that the gauge-independent critical point αc=2π/3\alpha_c=2\pi/3 obtained by the inversion method to the lowest order will be reduced to the result αc=π/3\alpha_c=\pi/3 of the Schwinger-Dyson equation in the infinite order limit, but its convergence is quite slow. This is shown by adding the chiral-invariant four-fermion interaction.Comment: CHIBA-EP-72, 13 pages (including 1 Table), LaTex fil

    Mapeamento de processos para a otimização da gestão empresarial

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    Orientador : Jane Mendes FerreiraTrabalho de Conclusão de Curso (especialização) - Universidade Federal do Paraná, Setor de Ciências Sociais Aplicadas, Curso de Especialização MBA em Gestão EstratégicaInclui referênciasResumo : O mapeamento de processos é considerado uma ferramenta útil para melhorar a gestão empresarial, por auxiliar na transparência do processo, pois os trabalhadores podem visualizar e compreender os aspectos necessários e o status de uma operação em todos os momentos. Como a empresa em questão trabalha somente com projetos especiais e completamente diferentes uns dos outros, o excesso de informações em diversas áreas e a falta de padronização de processos internos fazem com que haja uma grande variação no que diz respeito ao atendimento, orçamento e execução dos projetos. O objetivo do presente trabalho é Identificar e mapear os principais processos da empresa a fim de documentar e estabelecer parâmetros de controle para uma gestão mais eficaz do negócio

    Dynamical Breakdown of Chirality and Parity in (2+1)-dimensional QED

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    In the (2+1)-dimensional QED with and without the Chern-Simons term, we find the non-local gauge in which there is no wavefunction renormalization for the fermion in the framework of the Schwinger-Dyson equation. By solving the Schwinger-Dyson equation in the non-local gauge, we find a finite critical value NfcN_f^c for the number of flavors NfN_f of four-component Dirac fermions, above which the chiral symmetry restores irrespective of presence or absence of the Chern-Simons term. In the same framework, we study the possibility of dynamical breakdown of the parity. It is shown that the parity is not dynamically broken. We discuss this reason from the viewpoint of the Schwinger-Dyson equation.Comment: 22 pages, LaTeX, to be published in Nucl. Phys.

    Mechanical Methods of Producing Biomaterials with Aligned Collagen Fibrils

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    Collagen has been used in various therapeutic medical devices, such as artificial dermis, bone, and cartilage, wherein the effectiveness of collagen mainly depends on its biological features of biocompatibility, biodegradability, bioresorbability, cell affinity, and weak antigenicity. Collagen is the main structural protein in the human body and is responsible for the mechanical properties of tissues and organs. The fundamental structural component of tendon tissue is uniaxially aligned collagen fibrils that run parallel to the geometrical axis. Thus, the fabrication of artificial tendons is an excellent example of developing biomaterials using collagen as a structural backbone. Previous attempts to construct aligned fibril-based biomaterials involved electrospinning, freeze drying, using a strong magnetic field, and mechanical methods, including shearing and tension during wet extrusion. Among these, mechanical methods have been extensively studied owing to their simplicity and effectiveness suitable for mass production. However, few review articles have focused on these mechanical methods. Thus, this article reviews the mechanical methods for creating biomaterials from aligned collagen fibril while discussing the other fabrication methods in brief

    Clinical Application of Unidirectional Porous Hydroxyapatite to Bone Tumor Surgery and Other Orthopedic Surgery

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    Unidirectional porous hydroxyapatite (UDPHAp) was developed as a remarkable scaffold characterized by a distinct structure with unidirectional pores oriented in the horizontal direction and connected through interposes. We evaluated the radiographic changes, clinical outcomes, and complications following UDPHAp implantation for the treatment of bone tumors. Excellent bone formation within and around the implant was observed in all patients treated with intralesional resection and UDPHAp implantation for benign bone tumors. The absorption of UDPHAp and remodeling of the bone marrow space was observed in 45% of the patients at a mean of 17 months postoperatively and was significantly more common in younger patients. Preoperative cortical thinning was completely regenerated in 84% of patients at a mean of 10 months postoperatively. No complications related to the implanted UDPHAp were observed. In a pediatric patient with bone sarcoma, when the defect after fibular resection was filled with UDPHAp implants, radiography showed complete resorption of the implant and clear formation of cortex and marrow in the resected part of the fibula. The patient could walk well without crutches and participate in sports activities. UDPHAp is a useful bone graft substitute for the treatment of benign bone tumors, and the use of this material has a low complication rate. We also review and discuss the potential of UDPHAp as a bone graft substitute in the clinical setting of orthopedic surgery

    Children with unilateral aural atresia

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    The effects of FM system fitted into the normal hearing ear (NHE) or a cartilage conduction hearing aid (CCHA) fitted into the affected ear (AE) on the speech recognition ability in noise were examined in children with unilateral congenital aural atresia (UCAA). In children with bilateral normal hearing (BNH), speech recognition score (SRS) was significantly decreased in the noisy environment of -5 dB signal-to-noise ratio (SNR), compared with those in quiet. In children with UCAA, SRS was significantly decreased in noisy environments of 0 and -5 dB SNR, compared with those in quiet. In noisy environments of 0 and -5 dB SNR, SRS in children with UCAA was significantly decreased, compared those in children with BNH. In the noisy environment of -5 dB SNR, SRS in UCAA children aided by FM system fitted into NHE was significantly better than those in unaided children in the same group. In the noisy environment of 0 dB SNR, SRS in UCAA children aided by CCHA into AE tended to be higher than those in unaided children in the same group. FM system and CCHA can be recommended as an audiological management for the improvement of speech recognition in children with UCHL in classrooms
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