1,411 research outputs found
Numerical simulations of flow and mass transport processes in the anterior chamber in the presence of an iris-fixated intraocular lens
Dual-PEEC Modeling of a Two-Port TEM Cell for VHF Applications
Two-port TEM cells with rectangular cross section are commonly used to produce plane electromagnetic waves with high electric field. The non-uniform structure makes the use of numerical methods extremely useful in the design phase in order to achieve a very good behavior of the TEM cell over a wide frequency range of operation. In this paper an extended version of PEEC is used to study a real device and results are compared with experimental ones
2D kinematics of the edge-on spiral galaxy ESO 379-G006
We present a kinematical study of the nearly edge-on galaxy ESO 379-G006 that
shows the existence of extraplanar ionized gas. With Fabry-Perot spectroscopy
at H-alpha, we study the kinematics of ESO 379-G006 using velocity maps and
position-velocity diagrams parallel to the major and to the minor axis of the
galaxy. We build the rotation curve of the disk and discuss the role of
projection effects due to the fact of viewing this galaxy nearly edge-on. The
twisting of the isovelocities in the radial velocity field of the disk of ESO
379-G006 as well as the kinematic asymmetries found in some position-velocity
diagrams parallel to the minor axis of the galaxy suggest the existence of
deviations to circular motions in the disk that can be modeled and explained
with the inclusion of a radial inflow probably generated by a bar or by spiral
arms. We succeeded in detecting extraplanar Diffuse Ionized Gas in this galaxy.
At the same time, from the analysis of position-velocity diagrams, we found
some evidence that the extraplanar gas could lag in rotation velocity with
respect to the midplane rotation.Comment: 61 pages, 15 figures. Accepted for publication in A
Increased flexibility in lab-on-chip design with a polymer patchwork approach
Nanofluidic structures are often the key element of many lab-on-chips for biomedical and environmental applications. The demand for these devices to be able to perform increasingly complex tasks triggers a request for increasing the performance of the fabrication methods. Soft lithography and poly(dimethylsiloxane) (PDMS) have since long been the basic ingredients for producing low-cost, biocompatible and flexible devices, replicating nanostructured masters. However, when the desired functionalities require the fabrication of shallow channels, the \u201croof collapse\u201d phenomenon, that can occur when sealing the replica, can impair the device functionalities. In this study, we demonstrate that a \u201cfocused drop-casting\u201d of h-PDMS (hard PDMS) on nanostructured regions, provides the necessary stiffness to avoid roof collapse, without increasing the probability of deep cracks formation, a drawback that shows up in the peel-off step, when h-PDMS is used all over the device area. With this new approach, we efficiently fabricate working devices with reproducible sub-100 nm structures. We verify the absence of roof collapse and deep cracks by optical microscopy and, in order to assess the advantages that are introduced by the proposed technique, the acquired images are compared with those of cracked devices, whose top layer, of h-PDMS, and with those of collapsed devices, made of standard PDMS. The geometry of the critical regions is studied by atomic force microscopy of their resin casts. The electrical resistance of the nanochannels is measured and shown to be compatible with the estimates that can be obtained from the geometry. The simplicity of the method and its reliability make it suitable for increasing the fabrication yield and reducing the costs of nanofluidic polymeric lab-on-chips
Uncertainty quantification in energy management procedures
Complex energy systems are made up of a number of components interacting together via different energy vectors. The assessment of their performance under dynamic working conditions, where user demand and energy prices vary over time, requires a simulation tool. Regardless of the accuracy of this procedure, the uncertainty in data, obtained both by measurements or by forecasting, is usually non-negligible and requires the study of the sensitivity of results versus input data. In this work, polynomial chaos expansion technique is used to evaluate the variation of cogeneration plant performance with respect to the uncertainty of energy prices and user requests. The procedure allows to obtain this information with a much lower computational cost than that of usual Monte-Carlo approaches. Furthermore, all the tools used in this paper, which were developed in Python, are published as free and open source software
A Source Identification Problem for the Electrical Activity of Brain During Hand Movement
A field source reconstruction of the dipoles modeling the activated area of the brain, while a subject performs the task of the voluntary motion of the hand, is solved. Experimental data resulting from fMRI are used for constraining the position of the equivalent dipole
A Validated Reversed-Phase HPLC Method for the Determination of Atorvastatin Calcium in Tablets
A Reversed-Phase Liquid Chromatographic (RP-LC) assay method was developed for the quantitative determination of atorvastatin calcium in the presence of its degradation products. The assay involved an isocratic elution of atorvastatin calcium in a LiChroCARTR 250*4 mm HPLC Cartridge LiChrospherR 100 RP-18 (5 ÎŒm) column using a mobile phase consisting of 0.1% acetic acid solution: acetonitrile (45:55, v/v), pH = 3.8. The flow rate was 0.8 mL/min and the analytes monitored at 246 nm. The assay method was found to be linear from 8.13 to 23.77 ÎŒg/mL. All the validation parameters were within the acceptance range. The developed method was successfully applied to estimate the amount of atorvastatin calcium in tablets.Fil: Simionato, Laura Daniela. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Departamento de TecnologĂa FarmacĂ©utica; ArgentinaFil: Ferello, L.. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Departamento de TecnologĂa FarmacĂ©utica; ArgentinaFil: Stamer. S.. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Departamento de TecnologĂa FarmacĂ©utica; ArgentinaFil: Repetto, M. F.. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Departamento de TecnologĂa FarmacĂ©utica; ArgentinaFil: Zubata, P. D.. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Departamento de TecnologĂa FarmacĂ©utica; ArgentinaFil: Segall, Adriana Ines. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Departamento de TecnologĂa FarmacĂ©utica; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay; Argentin
- âŠ