656 research outputs found
Medial dorsal cutaneous nerve entrapment following inversion ankle sprain
The medial dorsal cutaneous nerve is one of the terminal branches of the superficial peroneal nerve that provides sensory innervation to the dorsum of the foot. It may be prone to injury by direct blow, iatrogenic surgical lesion or in rare situations secondary to ankle sprains. The authors report a case of persistent ankle pain in a female patient caused by a post- traumatic compressive neuropathy of the medial dorsal cutaneous nerve secondary to an ankle sprain which was successfully surgically treated with complete resolution of the symptoms
Ambipolar diffusion in the Bifrost code
Ambipolar diffusion is a physical mechanism related to the drift between
charged and neutral particles in a partially ionized plasma that is key in many
different astrophysical systems. However, understanding its effects is
challenging due to basic uncertainties concerning relevant microphysical
aspects and the strong constraints it imposes on the numerical modeling. Our
aim is to introduce a numerical tool that allows us to address complex problems
involving ambipolar diffusion in which, additionally, departures from
ionization equilibrium are important or high resolution is needed. The primary
application of this tool is for solar atmosphere calculations, but the methods
and results presented here may also have a potential impact on other
astrophysical systems. We have developed a new module for the stellar
atmosphere Bifrost code that improves its computational capabilities of the
ambipolar diffusion term in the Generalized Ohm's Law. This module includes,
among other things, collision terms adequate to processes in the coolest
regions in the solar chromosphere. As a key feature of the module, we have
implemented the Super Time-Stepping (STS) technique, that allows an important
acceleration of the calculations. We have also introduced hyperdiffusion terms
to guarantee the stability of the code. We show that to have an accurate value
for the ambipolar diffusion coefficient in the solar atmosphere it is necessary
to include as atomic elements in the equation of state not only hydrogen and
helium but also the main electron donors like sodium, silicon and potassium. In
addition, we establish a range of criteria to set up an automatic selection of
the free parameters of the STS method that guarantees the best performance,
optimizing the stability and speed for the ambipolar diffusion calculations. We
validate the STS implementation by comparison with a self-similar analytical
solution.Comment: Accepted in A&A, 10 pages, 7 figure
The subjective body of nursing academic: dimensions of sensoperception
Objetivo: identificar a maneira como acadêmicos de enfermagem visualizam o próprio corpo a partir do tato. Metodologia: estudo descritivo, de abordagem qualitativa com destaque para a subjetividade, feito com 33 alunos de graduação em enfermagem da Universidade Federal do Rio Grande do Norte/UFRN. Resultados: as respostas obedecem a um roteiro céfalo-caudal frente a um modelo anatomicamente incorporado para o exame físico. Os acadêmicos manifestaram gostar das partes que se situam na cabeça, tronco e não gostar daquelas referentes aos membros inferiores configurando um esquema corporal idealizado frente um corpo concreto e não aceito, embora tenha que conviver com o mesmo. Conclusão: mediante o estudo foi possível avaliar o quão importante é a relação desses estudantes com seu corpo e sua influência de cunho psicossocial e, ainda num sentido projetivo reflete a relação frente ao corpo dos portadores de transtornos mentais e comportamentais, objeto do seu cuidado
Molecular Identification Of Cultivable Bacteria From Infected Root Canals Associated With Acute Apical Abscess
The objective of this study was to investigate the bacterial composition present in root canals of teeth associated with acute apical abscess by molecular identification (16S rRNA) of cultivable bacteria. Two hundred and twenty strains isolated by culture from 20 root canals were subjected to DNA extraction and amplification of the 16S rRNA gene (PCR), followed by sequencing. The resulting nucleotide sequences were compared to the GenBank database from the National Center of Biotechnology Information through BLAST. Strains not identified by sequencing were submitted to clonal analysis. The association of microbiological findings with clinical features and the association between microbial species were also investigated. Fifty-nine different cultivable bacteria were identified by 16S rRNA gene sequencing, belonging to 6 phyla, with an average number of 6 species per root canal. Molecular approaches allowed identification of 99% of isolates. The most frequently identified bacteria were Prevotella spp., Pseudoramibacter alactolyticus, Parvimonas micra, Dialister invisus, Filifactor alocis, and Peptostreptococcus stomatis. Positive association was found between Prevotella buccae and Pseudoramibacter alactolyticus and between Parvimonas micra and Prevotella nigrescens (both p<0.05). It was concluded that the microbiota of infected root canals associated with acute apical abscess is diverse and heterogeneous, composed mainly of anaerobic Gram-negative bacteria, with the great majority belonging to the phyla Firmicutes and Bacteroidetes.27331832
On the effect of the wall slip boundary conditon
This work describes the implementation and assessment
of the wall slip boundary condition in a 3D numerical
modelling code, based on the finite volume method, that
is being developed by the research team. Several
phenomenological models relating the velocity and the
shear stress at the wall were implemented. The
capabilities of the new numerical code are illustrated
with three case studies where the wall slip boundary
conditions play an important role, namely the flow in a
smooth contraction, the stick-slip phenomenon an the
flow in a profile extrusion die. The results obtained are
qualitatively in accordance with the theoretical
expectations and evidence the importance of wall slip
Preparo de soluções.
Introdução; Cuidados gerais no preparo das soluções; Concentração de soluções; Diluição de soluções; Transformações mais usadas; exercicios sobre calculos de soluções;bitstream/CNPA-2009-09/14619/1/CIRTEC42.pd
Setting the optimal sheet thickness distribution for plastics thermoforming by multi-objective optimization
Thermoforming is a thermoplastic processing technique commonly used in the rigid packaging industry. The process comprises a heating stage, which aims at allowing the sheet to acquire the required deformability, a deformation stage, in which the sheets conform to the mould surface, and, finally, a cooling stage, which allows the part to be extracted from the mould without distorting. Since there are several processing variables associated with those stages, optimizing the thermoforming process is a complex task. In this work, a multi-objective optimization evolutionary algorithm is proposed to optimize the plastics thermoforming process. For that purpose, the thickness distribution of the final part was optimized considering that it is manufactured from uniform temperature sheets with different thickness distributions, such as constant and spline and concentric profiles. The aims were to minimize the sheet volume, as it implies less material use; assure a minimum value for the part thickness distribution, to avoid hindering its mechanical behavior; and minimize the thickness heterogeneity, i.e., the difference between the thickness of the part and a reference thickness. The Pareto optimal solutions found by the algorithm correspond to different thickness profiles for the three different sheet shapes. In all cases, an improvement of the different profiles along the successive generations of the evolutionary algorithm was obtained, which are related to the objectives considered. Moreover, the initial sheet thickness distribution was found to clearly influence the optimization process. The results obtained for these three different initial sheet shapes indicate that the proposed methodology is valid, providing solutions with physical meaning and with great potential to be applied in more complex cases
Slip flows of Newtonian and viscoelastic fluids in a 4:1 contraction
This work presents a numerical study of the 4:1 planar contraction flow of a viscoelastic fluid described
by the simplified Phan-Thien–Tanner model under the influence of slip boundary conditions at the channel
walls. The linear Navier slip law was considered with the dimensionless slip coefficient varying in the
range ½0; 4500. The simulations were carried out for a small constant Reynolds number of 0.04 and Deborah
numbers (De) varying between 0 and 5. Convergence could not be achieved for higher values of the
Deborah number, especially for large values of the slip coefficient, due to the large stress gradients near
the singularity of the reentrant corner.
Increasing the slip coefficient leads to the formation of two vortices, a corner and a lip vortex. The lip
vortex grows with increasing slip until it absorbs the corner vortex, creating a single large vortex that
continues to increase in size and intensity. In the range De = 3–5 no lip vortex was formed. The flow is
characterized in detail for De ¼ 1 as function of the slip coefficient, while for the remaining De only
the main features are shown for specific values of the slip coefficient.The authors gratefully acknowledge funding by COMPETE, FEDER and Fundacao para a Ciencia e a Tecnologia (FCT) through projects PEst-C/CTM/LA0025/2013 (Strategic Project - LA 25 - 2013-2014, PTDC/EME-MFE/113988/2009 and PTDC/EME-MFE/114322/2009. AMA would also like to thank FCT for the financial support through the scholarship SFRH/BPD/75436/2010
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