671 research outputs found
To Kick Against the Pricks: An Examination of the Oresteia and the Acts of the Apostles
The major themes found in the Oresteia and the books of Luke and Acts of the Apostles are compared. By focusing on the similarities found in the themes of Justice, Religion, and New versus Old, the reader may determine if the phrase in question is being used as a literary allusion in the book of Acts of the Apostles to the Oresteia trilogy. The author believes this to be the case and believes that to arrive at a full understanding of the literary meaning of the phrase in question, an understanding of the major themes of the Oresteia is necessary
Process Development for Batch Production of Micro-Milling Tools Made of Silicon Carbide by Means of the Dry Etching Process
Downsized and complex micro-machining structures have to meet quality requirements concerning geometry and convince through increasing functionality. The development and use of cutting tools in the sub-millimeter range can meet these demands and contribute to the production of intelligent components in biomedical technology, optics or electronics. This article addresses the development of double-edged micro-cutters, which consist of a two-part system of cutter head and shaft. The cutting diameters are between 50 and 200 μm. The silicon carbide cutting heads are manufactured from the solid material using microsystem technology. The substrate used can be structured uniformly via photolithography, which means that 5200 homogeneous micro-milling heads can be produced simultaneously. This novel batch approach represents a contrast to conventionally manufactured micro-milling cutters. The imprint is taken by means of reactive ion etching using a mask made of electroplated nickel. Within this dry etching process, characteristic values such as the etch rate and flank angle of the structures are critical and will be compared in a parameter analysis. At optimal parameters, an anisotropy factor of 0.8 and an etching rate of 0.34 µm/min of the silicon carbide are generated. Finally, the milling heads are diced and joined. In the final machining tests, the functionality is investigated and any signs of wear are evaluated. A tool life of 1500 mm in various materials could be achieved. This and the milling quality achieved are in the range of conventional micro-milling cutters, which gives a positive outlook for further development
Cell-based maximum entropy approximants for three-dimensional domains: Application in large strain elastodynamics using the meshless total Lagrangian explicit dynamics method
We present the cell-based maximum entropy (CME) approximants in E3 space by constructing the smooth approximation distance function to polyhedral surfaces. CME is a meshfree approximation method combining the properties of the maximum entropy approximants and the compact support of element-based interpolants. The method is evaluated in problems of large strain elastodynamics for three-dimensional (3D) continua using the well-established meshless total Lagrangian explicit dynamics method. The accuracy and efficiency of the method is assessed in several numerical examples in terms of computational time, accuracy in boundary conditions imposition, and strain energy density error. Due to the smoothness of CME basis functions, the numerical stability in explicit time integration is preserved for large time step. The challenging task of essential boundary condition (EBC) imposition in noninterpolating meshless methods (eg, moving least squares) is eliminated in CME due to the weak Kronecker-delta property. The EBCs are imposed directly, similar to the finite element method. CME is proven a valuable alternative to other meshless and element-based methods for large-scale elastodynamics in 3D. A naive implementation of the CME approximants in E3 is available to download at https://www.mountris.org/software/mlab/cme.Fil: Mountris, Konstantinos A.. Universidad de Zaragoza; EspañaFil: Bourantas, George C.. University of Western Australia; AustraliaFil: Millán, Raúl Daniel. Universidad Nacional de Cuyo. Facultad de Ciencias Aplicadas a la Industria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; ArgentinaFil: Joldes, Grand R.. University of Western Australia; AustraliaFil: Miller, Karol. Cardiff University; Reino Unido. University of Western Australia; AustraliaFil: Pueyo, Esther. Centro de Investigacion Biomedica En Red.; España. Universidad de Zaragoza; EspañaFil: Wittek, Adam. University of Western Australia; Australi
Biomechanical Simulation of Electrode Migration for Deep Brain Stimulation
International audienceDeep Brain Stimulation is a modern surgical technique for treating patients who suffer from affective or motion disorders such as Parkinson's disease. The efficiency of the procedure relies heavily on the accuracy of the placement of a micro-electrode which sends electrical pulses to a specific part of the brain that controls motion and affective symptoms. However, targeting this small anatomical structure is rendered difficult due to a series of brain shifts that take place during and after the procedure. This paper introduces a biomechanical simulation of the intra and postoperative stages of the procedure in order to determine lead deformation and electrode migration due to brain shift. To achieve this goal, we propose a global approach, which accounts for brain deformation but also for the numerous interactions that take place during the procedure (contacts between the brain and the inner part of the skull and falx cerebri, effect of the cerebro-spinal fluid, and biomechanical interactions between the brain and the electrodes and cannula used during the procedure). Preliminary results show a good correlation between our simulations and various results reported in the literature
A voxelized immersed boundary (VIB) finite element method for accurate and efficient blood flow simulation
We present an efficient and accurate immersed boundary (IB) finite element
(FE) method for internal flow problems with complex geometries (e.g., blood
flow in the vascular system). In this study, we use a voxelized flow domain
(discretized with hexahedral and tetrahedral elements) instead of a box domain,
which is frequently used in IB methods. The proposed method utilizes the
well-established incremental pressure correction scheme (IPCS) FE solver, and
the boundary condition-enforced IB (BCE-IB) method to numerically solve the
transient, incompressible Navier--Stokes flow equations. We verify the accuracy
of our numerical method using the analytical solution for the Poiseuille flow
in a cylinder, and the available experimental data (laser Doppler velocimetry)
for the flow in a three-dimensional 90{\deg} angle tube bend. We further
examine the accuracy and applicability of the proposed method by considering
flow within complex geometries, such as blood flow in aneurysmal vessels and
the aorta, flow configurations that would otherwise be difficult to solve by
most IB methods. Our method offers high accuracy, as demonstrated by the
verification examples, and high applicability, as demonstrated through the
solution of blood flow within complex geometry. The proposed method is
efficient, since it is as fast as the traditional finite element method used to
solve the Navier--Stokes flow equations, with a small overhead (not more than
5) due to the numerical solution of a linear system formulated for the IB
method.Comment: arXiv admin note: substantial text overlap with arXiv:2007.0208
Engagement and Learning from a team-based mini-project in mechatronic engineering
We outline our experiences with hidden and unsignposted learning by us and by our students arising from a team-based project activity in a 3rd-year undergraduate engineering module in the general Mechatronics area. We discuss the hidden learning achieved in areas such as team communications, team management, problem-solving skills, and communication through the media of student-produced video and presentations, as well as technical engineering reports. We describe the enablement of student reflection on their learning and its benefits and use these reflections to evidence various aspects of their learning. The work is situated within the literature on innovations and quality of STEM education
Charged rho meson production in neutrino-induced reactions at E_nu = 10 GeV
The neutrinoproduction of charged mesons on nuclei and nucleons is
investigated for the first time at moderate energies ( 10
GeV), using the date obtained with SKAT bubble chamber. No strong nuclear
effects are observed in and production. The fractions of
charged and neutral pions originating from decays are obtained and
compared with higher energy data. From analysis of the obtained and available
data on and (892) neutrinoproduction, the strangeness
suppression factor in the quark string fragmentation is extracted: . Estimations are obtained for cross sections of quasiexclusive
single and coherent neutrinoproduction on nuclei. The
estimated coherent cross section = (0.29 cm is compatible with theoretical predictions.Comment: 7 pages, 6 figure
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