3D Investigation of Droplet Generation in a Miniaturized Coflowing Device Using Micro-Computed Tomography

2020 ◽  
Author(s):  
Julia Schuler ◽  
Laura Maria Neuendorf ◽  
Kai Petersen ◽  
Norbert Kockmann
Keyword(s):  
Computed Tomography ◽  
Droplet Formation ◽  
Outer Diameter ◽  
Micro Computed Tomography ◽  
Flow Rates ◽  
Thin Polymer ◽  
Major Interest ◽  
Inner Diameter ◽  
The Subject ◽  
Polymer Tube

Abstract For many applications, such as liquid-liquid or gas-liquid reactions, the generation of monodisperse droplets is of major interest. Therefore, knowledge about the physics of droplet formation is essential and the subject of numerous studies. Droplet formation is usually investigated using optical cameras, which makes optical accessibility necessary. Furthermore, properties defining droplet evolution is obtained from 2D images. In this work, we present a methodology for the 3D investigation of droplet formation in the laminar regime using micro-computed tomography. A special imaging concept and image processing, incorporating the use of a convolutional neural network, is presented. Water droplets are injected into a continuous polydimethylsiloxane stream in a coflowing configuration using a cannula with an inner diameter di = 800 μm and an outer diameter do = 1050 μm that is centered in a thin polymer tube with an inner diameter di = 1600 μm. Volume flow rates of polydimethylsiloxane and water are varied between 0.2 and 0.3 mL min−1. Furthermore, the influence of cannula positioning on droplet formation is investigated. Different quantitative 3D properties are extracted from the CT scans, such as droplet volume and surface of the interface. Thereby, different stages of droplet formation can be identified and the physical understanding of droplet formation is improved.

scholarly journals Unusual Deviation of the Main Foramen from the Root Apex

2016 ◽  
Vol 27 (5) ◽  
pp. 589-591 ◽  
Author(s):  
Marco Aurélio Versiani ◽  
Hany Mohamed Aly Ahmed ◽  
Manoel Damião de Sousa-Neto ◽  
Gustavo De-Deus ◽  
Paul Michael Howell Dummer
Keyword(s):  
Computed Tomography ◽  
Short Communication ◽  
Root Apex ◽  
Micro Computed Tomography ◽  
Tooth Type ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Substantial Distance

Abstract The relationship of the main foramen to the anatomic root apex has been the subject of several studies. Although they are anatomically close, they rarely coincide, and their distance can vary according to age or tooth type, ranging from 0.2 to 3.0 mm. The aim of this short communication was to evaluate the distance between the main foramen of independent middle mesial canals (MMCs) and the anatomical mesial root apex of mandibular first molars using the micro-computed tomography. Twenty-five mandibular first molars with MMCs were scanned (resolution of 9.9 µm), and the distance from its main foramen to the anatomical apex was evaluated. Overall, the distance ranged from 0.2 to 2.4 mm; however, in 3 specimens the distance was greater than 3 mm. This report demonstrates that the exit of the main foramen of the MMC varies considerably and could approach a substantial distance from the anatomical apex greater than previously reported in the literature.

scholarly journals Cross-sectional analysis of tubular polymer semi-finished products using ultrasound in comparison with other measuring methods

2020 ◽  
Vol 6 (3) ◽  
pp. 151-154
Author(s):  
Olga Sahmel ◽  
Stefan Siewert ◽  
Wolfram Schmidt ◽  
Klaus-Peter Schmitz ◽  
Niels Grabow
Keyword(s):  
Wall Thickness ◽  
Biomedical Engineering ◽  
Measuring Method ◽  
Outer Diameter ◽  
Micro Computed Tomography ◽  
Cross Sectional ◽  
Biodegradable Poly ◽  
Ultrasonic Measuring ◽  
Inner Diameter ◽  
Sectional Analysis

AbstractIn the sector of biomedical engineering and implant technology, high-precision geometry is often decisive for successful end product functionalization. Especially in the production of tubular polymer semi-finished products, e.g. for stent fabrication, it is important to assure the desired parameters, such as inner and outer diameter and wall thickness. Within the current study we analyzed semifinished products for manufacturing of polymeric stents using three different methods. Biodegradable poly-L-lactide (PLLA) tubes were examined by means of micro computed tomography, ultrasonic scanning and scanning electron microscopy. The final evaluation presents clear advantages of the ultrasonic measuring method for the measurement of outer and inner diameter and wall thickness.

Model Calculations on Micropump Using Reciprocating Motion of Magnetic Material Ball

2014 ◽  
Author(s):  
Hiroshige Kumamaru ◽  
Hayata Fujiwara ◽  
Yoshihisa Nomura ◽  
Kazuhiro Itoh
Keyword(s):  
Experimental Data ◽  
Magnetic Material ◽  
Flow Rate ◽  
Maximum Flow ◽  
Outer Diameter ◽  
Reciprocating Motion ◽  
Model Calculations ◽  
Flow Rates ◽  
Pump Head ◽  
Inner Diameter

The authors are developing a micropump which combines reciprocating motion of a magnetic material ball in a pumping channel and four passive check valves. An additional experiment has been performed for one combination of the ball outer diameter and the channel inner diameter, and results of this experiment are presented in this paper. Including the previous experiments performed by the authors, the maximum pump head of ∼620 mm and the maximum flow rate of ∼7.5 mL/min have been obtained in the present micropump. Also, in this study, model calculations have been performed in order to predict the pump performance, i.e. the relation between pump head and flow rate. Calculated flow rates agree well with experimental data for larger gaps between the ball outer diameter and the pumping-channel inner diameter; however, calculated flow rates are larger than the experimental data for smaller gaps. Therefore, it is necessary to improve the calculation models, in particular by calculating leak flow rate in the pumping channel as a flow through a nozzle instead of that through an orifice.

A capillary and microchip-based nanoelectrospray emitter using a mesoporous membrane

2008 ◽  
Vol 86 (11) ◽  
pp. 1055-1062 ◽  
Author(s):  
Shuqin Su ◽  
Richard D Oleschuk
Keyword(s):  
Porous Membrane ◽  
Fused Silica ◽  
Porous Polymer ◽  
Outer Diameter ◽  
Microfluidic Chips ◽  
Flow Rates ◽  
Fused Silica Capillaries ◽  
Silica Capillaries ◽  
Fused Silica Capillary ◽  
Inner Diameter

A method is described for the fabrication of multipath electrospray emitters using hydrophobic porous polymer membranes. Polysulphone (PSF) and polycarbonate (PC) membranes, which possess pores with well-defined sizes, are glued onto the exit aperture of fused-silica capillaries or microfluidic chips to create multipaths to assist electrospray at moderate nano flow rates (e.g., 50–500 nL/min). A capillary-based multipath emitter fabricated with either PSF or PC membranes was prepared with a fused-silica capillary with 75 µm inner diameter and 360 µm outer diameter. Relative effects on electrospray performance at different flow rates, electrospray voltages, and solvent compositions are probed. The sensitivity and stability of electrospray signals were enhanced through spraying from multiple pores on the membrane. An embossed polycarbonate microchip was also interfaced to the mass spectrometer using the meso porous membrane approach.Key words: nanoelectrospray, membrane, emitter, multipaths, microchip.

Cortical and trabecular bone parameters from HR-Pqct images at the Tibia: a local comparison with synchrotron radiation micro-computed tomography

2013 ◽  
Author(s):  
Agnes Ostertag ◽  
Francoise Peyrin ◽  
Sylvie Fernandez ◽  
Jean-Denis Laredo ◽  
Vernejoul Marie-Christine De ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Synchrotron Radiation ◽  
Trabecular Bone ◽  
Micro Computed Tomography ◽  
Bone Parameters ◽  
Local Comparison

Morphology and Affinities of Ampelocissites Seeds (Vitaceae: Ampelopsis clade) from the Paleogene of Texas, USA

2020 ◽  
Vol 45 (3) ◽  
pp. 478-482
Author(s):  
Steven R. Manchester
Keyword(s):  
Computed Tomography ◽  
Cross Sections ◽  
Seed Coat ◽  
Ct Scanning ◽  
Seed Morphology ◽  
Early Eocene ◽  
Micro Computed Tomography ◽  
X Ray ◽  
Fossil Seeds ◽  
Fossil Genus

Abstract—The type material on which the fossil genus name Ampelocissites was established in 1929 has been reexamined with the aid of X-ray micro-computed tomography (μ-CT) scanning and compared with seeds of extant taxa to assess the relationships of these fossils within the grape family, Vitaceae. The specimens were collected from a sandstone of late Paleocene or early Eocene age. Although originally inferred by Berry to be intermediate in morphology between Ampelocissus and Vitis, the newly revealed details of seed morphology indicate that these seeds represent instead the Ampelopsis clade. Digital cross sections show that the seed coat maintains its thickness over the external surfaces, but diminishes quickly in the ventral infolds. This feature, along with the elliptical chalaza and lack of an apical groove, indicate that Ampelocissites lytlensis Berry probably represents Ampelopsis or Nekemias (rather than Ampelocissus or Vitis) and that the generic name Ampelocissites may be useful for fossil seeds with morphology consistent with the Ampelopsis clade that lack sufficient characters to specify placement within one of these extant genera.

Comparison of the Aditus ad Antrum Diameter on CT between Patients with Chronic Otitis Media and Healthy Individuals

2019 ◽  
Vol 15 (10) ◽  
pp. 990-993 ◽  
Author(s):  
Elif Gündoğdu ◽  
Uğur Toprak
Keyword(s):  
Computed Tomography ◽  
Otitis Media ◽  
Middle Ear ◽  
Healthy Subjects ◽  
Normal Values ◽  
Chronic Otitis Media ◽  
Healthy Individuals ◽  
Inner Diameter ◽  
Male Patients ◽  
The Right

Background: The middle ear cavity is ventilated through the aditus ad antrum. Aditus blockage contributes to the pathology of otitis media. Objective: To determine the normal values of the aditus ad antrum diameter on computed tomography and to investigate its relationship with chronic otitis media and related pathologies (tympanosclerosis and myringosclerosis). Methods: The temporal CT images of 162 individuals were evaluated retrospectively. In the axial sections, the inner diameter of the aditus was measured at the narrowest point at the cortex. The differences in diameter were compared between diseased and healthy ears. Results: In healthy individuals, the diameter was narrower in women. There was no difference between the right and left ears in healthy subjects. No correlation was found between age and diameter. In male patients with myringosclerosis, the diameter was slightly narrower on both sides but more marked on the left. In female patients with myringosclerosis, the diameter in both ears was slightly narrower. In cases of otitis media and tympanosclerosis, the diameter was less than that of healthy individuals, despite the lack of statistically significant result in all cases. Conclusion: The aditus ad antrum was narrower in diseased ears, indicating that a blocked aditus may contribute to the development of otitis media, as well as mucosal diseases.

INVESTIGATION OF AUBRITES THROUGH INTEGRATION OF 3D MODAL MINERALOGY WITH X-RAY MICRO-COMPUTED TOMOGRAPHY AND GEOCHEMISTRY

2018 ◽  
Author(s):  
Zoë E. Wilbur ◽  
◽  
Arya Udry ◽  
Arya Udry ◽  
Daniel M. Coleff ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Micro Computed Tomography ◽  
X Ray
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