Vortex distribution in a confining potential

We study a model of interacting vortices in a type II superconductor. In the weak coupling limit, we constructed a mean-field theory which allows us to accurately calculate the vortex density distribution inside a confining potential. In the strong coupling limit, the correlations between the particles become important and the mean-field theory fails. Contrary to recent suggestions, this does not imply failure of the Boltzmann-Gibbs statistical mechanics, as we clearly demonstrate by comparing the results of Molecular Dynamics and Monte Carlo simulations

Isothermal adsorption of polyampholytes on charged nanopatterned surfaces

We investigate the adsorption of neutral polyampholytes on charged nanopatterned surfaces. The surfaces have charged domains but are overall neutral. To perform efficient simulations, we use an approach which combines the explicit form of the interaction potential between the polyampholyte monomers and the surface with a 3d Ewald summation method. We observe that the amount of adsorption and the structure of the adsorbed polyampholytes depend strongly on the surface pattern, the relative size of the surface domains, and the charge distribution along the polyampholyte backbone

A importância da evidência

Evidence-based Medicine (EBM) has become a major source of medical knowledge. It handles complexities of virtually every method or technique used in research. The knowledge on how the EBM researcher retrieves information, judges for relevance and analyzes derived data is invaluable for the skillful reader of medical scientific reports

Effects of the dielectric discontinuity on the counterion distribution in a colloidal suspension

We introduce a new method for simulating colloidal suspensions with spherical colloidal particles of dielectric constant different from the surrounding medium. The method uses exact calculation of the Green function to obtain the ion-ion interaction potential in the presence of a dielectric discontinuity at the surface of the colloidal particle. The new method is orders of magnitude faster than the traditional approaches based on series expansions of the interaction potential

Weak and Strong Coupling Theories for Polarizable Colloids and Nano-Particles

A theory is presented which allows us to accurately calculate the density profile of monovalent and multivalent counterions in suspensions of polarizable colloids or nano-particles. In the case of monovalent ions, we derive a weak-coupling theory that explicitly accounts for the ion-image interaction, leading to a modified Poisson-Boltzmann equation. For suspensions with multivalent counterions, a strong-coupling theory is used to calculate the density profile near the colloidal surface and a Poisson-Boltzmann equation with a renormalized boundary condition to account for the counterion distribution in the far-field. All the results are compared with the Monte Carlo simulations, showing an excellent agreement between the theory and the simulations

Simulations of Coulomb systems with slab geometry using an efficient 3D Ewald summation method

We present a new approach to efficiently simulate electrolytes confined between infinite charged walls using a 3d Ewald summation method. The optimal performance is achieved by separating the electrostatic potential produced by the charged walls from the electrostatic potential of electrolyte. The electric field produced by the 3d periodic images of the walls is constant inside the simulation cell, with the field produced by the transverse images of the charged plates canceling out. The non-neutral confined electrolyte in an external potential can be simulated using 3d Ewald summation with a suitable renormalization of the electrostatic energy, to remove a divergence, and a correction that accounts for the conditional convergence of the resulting lattice sum. The new algorithm is at least an order of magnitude more rapid than the usual simulation methods for the slab geometry and can be further sped up by adopting a particle–particle particle–mesh approach

Visualização em tempo real de um modelo esparso de mistura paramétrica para síntese da BTF

As funções de textura bidirecionais (Bidirectional Texture Functions - BTF) permitem visualizações de alta qualidade de materiais reais, que exibem detalhes complexos na sua aparência, e que não podem ser fielmente representados por funções paramétricas mais simples. Representações fíeis deste tipo de materiais requerem grandes quantidades de dados, dificultando a sua visualização em tempo real. A compressão de BTFs constitui um compromisso entre qualidade visual e tempo de síntese. Este artigo apresenta um visualizador a correr integralmente no GPU, usando um motor de ray tracing, de uma representação recente para BTFs, o Modelo Esparso de Mistura Paramétrica (Sparse Parametric Mixture Model - SPMM). A escalabilidade com o número de BTFs e o número de luzes é também estudado.Fundação para a Ciência e Tecnologi

Landslide risk profiles for municipal land use planning in Portugal

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Free Non-vascularized Toe Phalangeal Transfers in Symbrachydactyly: Outcome Analysis

Free nonvascularized toe phalangeal transfer is an established surgical option for the reconstruction of hypoplastic digits. The purpose of the present study was to evaluate our experience with this procedure and to assess bone growth and digit function as well foot morbidity. Material and Methods We retrospectively evaluated the clinical records for all children with symbrachydactyly submitted to free nonvascularized toe phalangeal transfer between 2002 and 2017. A total of 8 patients were included. We summoned the patients to na appointment to clinically assess the range ofmotion, the stability, and the alignment of the neo-joint. We radiographically measured the final length and the expected percentage of growth of the transferred phalanx. We also evaluated the foot for comorbidities. Results The mean age at the time of the first surgery was 19 months (range: 8–42 months). A total of 20 phalanges were harvested: 16 total proximal phalanges, 2 middle phalanges, 1 subtotal proximal phalanx, and 1 accessory thumb phalanx. The distal part of one proximal phalanx was trimmed because the skin pocket was too tight. Two patients underwent a secondary procedure to release the syndactyly. One transfer required revision surgery due to distal tip necrosis and exposition of the transferred phalanx. In the present series, the overall clinical and radiographic outcomes were compatible to those reported in other studies. Discussion The main limitation of the nonvascularized toe phalanx transfer is the preexisting soft tissue envelope of the finger and the limited growth potential of the transferred bone. Conclusion Irrespective of the amount of growth achieved in the transferred phalanx, the actual transfer and growth attained should not be viewed as the end result, but rather as a means of providing a stable and functional joint.La transferência no vascularizada y libre de la falange del pie es una opción quirúrgica establecida para la reconstrucción de dedos hipoplásicos. El objetivo de este estudio fue analizar nuestra experiencia con este procedimiento y evaluar el crecimiento óseo y la función digital, así como la morbilidad del pie. Material y Métodos Analizamos retrospectivamente el proceso clínico de los niños (n ¼ 8) con simbraquidactilia que se sometieron a una transferencia no vascularizada y libre de la falange del pie entre 2002 y 2017. Hicimos una consulta para evaluar clínicamente el rango de movilidad, la estabilidad, y la alineación de la nueva articulación. Medimos la longitud final y el porcentaje de crecimiento esperado de la falange transferida. Evaluamos el pie para la comorbilidad. Resultados La edad media al momento de la cirugía fue de 19 meses (rango: 8–42 meses). Se recogieron un total de 20 falanges: 16 falanges proximales totales, 2 falanges medianas, 1 falange proximal subtotal, y 1 falange accesoria del pulgar. La parte distal de una falange proximal se sacrificó porque la envoltura de la piel estaba demasiado apretada. Dos pacientes se sometieron a un procedimiento secundario por la liberación de sindactilia. Una transferencia requirió revisión debido a la necrosis de la porción distal y la exposición de la falange transferida. En la presente serie, los resultados clínicos y radiográficos generales fueron compatibles con los descritos por otros estudios. Discusión Las principales limitaciones de la transferencia no vascularizada y libre de las falanges del pie son la envoltura preexistente de tejidos blandos y el potencial de crecimiento limitado del hueso transferido. Conclusión Independientemente del crecimiento obtenido con la transferencia de la falange, esto no debe verse como el resultado final, sino como un medio paramejorar la estabilidad y la funcionalidad de la nueva articulación.info:eu-repo/semantics/publishedVersio