CFD SIMULATION AND CHARACTERIZATION OF A DEVICE FOR POWDERED PHARMACEUTICALS AND BIOLOGICALS DELIVERY

2006 ◽  
Vol 06 (03) ◽  
pp. 285-297
Author(s):  
FANG LIU ◽  
WEI HE ◽  
CHUNLI CAO ◽  
YI LIU
Keyword(s):  
High Speed ◽  
Cfd Simulation ◽  
Biological Effects ◽  
Particle Interaction ◽  
Mean Velocity ◽  
Micro Particles ◽  
Venturi Effect ◽  
Underlying Principle ◽  
Wide Range

Advances in molecular biology have produced a wide range of protein and peptide-based drugs. Equally, it is required to explore various technologies and capabilities to deliver those drugs. A unique medical device, the hand-held biolistics, is developed for powdered pharmaceuticals/biologicals transdermal delivery. The underlying principle is to accelerate micro-particles by means of a high-speed helium gas to an appropriate momentum to penetrate the outer layer of the skin to elicit desirable pharmaceutical/biological effects. The novelty of this hand-held biolistics is using the venturi effect to entrain micron-sized protein and peptide drugs into an established quasi-steady transonic jet flow and accelerate them toward the target. In this paper, computational fluid dynamics is utilized to characterize prototype biolistic system. The key features of gas dynamics and gas–particle interaction are presented. The overall capability of the biolistic delivery system is discussed and demonstrated. The statistical analyses show that the particles have achieved a mean velocity of 628 m/s as representatives of extracellular vaccine delivery applications.

BWO-Characterization of Materials and Devices at Frequencies 100-1000 GHz.

2000 ◽  
Vol 631 ◽  
Author(s):  
A. A. Volkov ◽  
V. B. Anzin ◽  
Yu. G. Goncharov ◽  
B. P. Gorshunov ◽  
G. A. Komandin ◽  
...  
Keyword(s):  
High Speed ◽  
Open Space ◽  
Frequency Tuning ◽  
High Radiation ◽  
Phase Measurements ◽  
Spectral Technique ◽  
Wide Range ◽  
Characterization Of Materials ◽  
Space Measurement

ABSTRACTWe have developed multipurpose spectral technique for amplitude and phase measurements at frequencies 100–1000 GHz based on the use of backward wave oscillators (BWOs) as sources of probing radiation. It utilizes to the utmost all the remarkable advantages of BWOs such as high radiation intensity, monochromaticity, polarization, as well as high speed and wide range of frequency tuning. Extremely simple and flexible open-space measurement geometries are used. The developed technique seems to be the most appropriate and promising for the reliable, precise and mass characterization of materials and devices at millimeter-submillimeter waves.

F.05 Characterization of NBCA glue polymerization for embolization of brain AVM’s

2016 ◽  
Vol 43 (S2) ◽  
pp. S19-S20
Author(s):  
BH Wang ◽  
D Pelz ◽  
D Lee ◽  
MR Boulton ◽  
SP Lownie
Keyword(s):  
High Speed ◽  
Contact Angles ◽  
Polymerization Rate ◽  
Physical Interaction ◽  
Wide Range ◽  
Glue Injection ◽  
Glue Embolization

Background: Brain arteriovenous malformations (AVM’s) are abnormal connections between arteries and veins. Endovascular glue embolization with N-butyl cyanoacrylate (NBCA) is an accepted form of treatment, with most complications related to timing of polymerization. Current literature reports a wide range of polymerization times with large discrepancies between in-vivo and in-vitro results. Methods: Polymerization time was measured for mixtures of lipiodol/NBCA of 50/50, 60/40, 70/30. The influence of pH, temperature and presence of biological catalysts on polymerization rate was investigated in-vivo using submerged droplet tests. PVA-C, silicone and endothelium surfaces were compared and contact angles were measured to assess physical interaction with NBCA. High-speed video of glue injection through a microcatheter was captured to characterize coaxial flow. Results: Polymerization rate increases with pH and temperature. A hydrophilic substrate such as PVA-C provides surface properties that are most similar to endothelium. Endothelium provides a catalytic surface that increases the rate of polymerization. Blood products further increase the polymerization rate with RBC’s providing almost instantaneous polymerization of NBCA upon contact. Characterization of coaxial flow shows dripping to jetting transition with significant wall effect. Conclusions: We have successfully deconstructed and characterized the dynamic behavior of NBCA embolization. A refined understanding of NBCA behavior could help reduce embolization-related complications.

scholarly journals Aerodynamic Analysis of a Supersonic Transport Aircraft at Landing Speed Conditions

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6615
Author(s):  
Andrea Aprovitola ◽  
Pasquale Emanuele Di Nuzzo ◽  
Giuseppe Pezzella ◽  
Antonio Viviani
Keyword(s):  
High Speed ◽  
Cfd Simulation ◽  
Vortex Breakdown ◽  
Delta Wing ◽  
Research Effort ◽  
Static Stability ◽  
Commercial Aviation ◽  
Supersonic Flight ◽  
Supersonic Transport ◽  
Wide Range

Supersonic flight for commercial aviation is gaining a renewed interest, especially for business aviation, which demands the reduction of flight times for transcontinental routes. So far, the promise of civil supersonic flight has only been afforded by the Concorde and Tupolev T-144 aircraft. However, little or nothing can be found about the aerodynamics of these aeroshapes, the knowledge of which is extremely interesting to obtain before the development of the next-generation high-speed aircraft. Therefore, the present research effort aimed at filling in the lack of data on a Concorde-like aeroshape by focusing on evaluating the aerodynamics of a complete aircraft configuration under low-speed conditions, close to those of the approach and landing phase. In this framework, the present paper focuses on the CFD study of the longitudinal aerodynamics of a Concorde-like, tailless, delta-ogee wing seamlessly integrated onto a Sears–Haack body fuselage, suitable for civil transportation. The drag polar at a Mach number equal to 0.24 at a 30 m altitude was computed for a wide range of angles of attack (0∘,60∘), with a steady RANS simulation to provide the feedback of the aerodynamic behaviour post breakdown, useful for a preliminary design. The vortex-lift contribution to the aerodynamic coefficients was accounted for in the longitudinal flight condition. The results were in agreement with the analytical theory of the delta-wing. Flowfield sensitivity to the angle of attack at near-stall and post-stall flight attitudes confirmed the literature results. Furthermore, the longitudinal static stability was addressed. The CFD simulation also evidenced a static instability condition arising for 15∘≤α≤20∘ due to vortex breakdown, which was accounted for.

Generation of Uniform Liquid Droplets in a Microfluidic Chip Using a High-Speed Gaseous Microflow

2016 ◽  
Author(s):  
Pooyan Tirandazi ◽  
Carlos H. Hidrovo
Keyword(s):  
Microfluidic Chip ◽  
High Speed ◽  
Gas Flow ◽  
Gaseous Medium ◽  
High Surface ◽  
Liquid Droplets ◽  
Microfluidic Systems ◽  
Alternative Scheme ◽  
Micro Particles ◽  
Wide Range

Miniaturized laboratory-on-a-chip systems have been extensively developed over the past decade as promising tools for a wide range of applications, specifically in chemical synthesis and biomedical diagnostics. Droplet-based microfluidic systems have become ubiquitous in such applications by providing essential tools to perform rapid as well as high throughput measurements on small volumes of fluids. Thus far, the majority of the research endeavors have been focused on liquid-liquid systems for generating microscale drops (typically water in oil). Droplets generated in liquid-liquid microfluidic systems tend to be very uniform in size, and due to high surface area to volume ratio of micro-droplets, heat and mass transfer occurs at higher rates as compared to continuous-flow microfluidics. Generation of droplets in a gaseous medium, on the other hand, have been widely used in applications that involve open environment liquid spraying, such as ink-jet printers. However, usually in such applications there is no control over either the size or frequency of the generated droplets, and as a result droplets formed in these systems are widely distributed in size. Here we demonstrate an alternative scheme for controlled generation of liquid droplets in a microfluidic chip using a high speed gas stream. We have incorporated the inertial effect of a high-speed gaseous medium with the flow-focusing geometry, fabricated in a PDMS chip, in order to generate droplets with controlled size. Flow regimes involved in this scheme may be divided in three main regions i.e. co-flow, jetting, and dripping among which only dripping regime is capable of producing distinct aqueous droplets in the channel. It should be noted that poor surface conditions and high gas flow rates may result in generation of satellite droplets together with the main droplet in the dripping region, which substantially affects the monodispersity of the droplets. The generated drops were collected thereafter and it is shown that monodisperse droplets with known size ranging from 50 μm to 100 μm in diameter can be achieved within the dripping flow regime. We believe this method offers beneficial opportunities for the next generation of Lab-on-a-chip devices in which the introduction of a gaseous medium is required, namely oxidation, detection of airborne particles, and formation of micro-particles and micro-gels. Furthermore, the high speed droplets generated in this method represent the basis for a new approach based on droplet pair collisions for fast efficient micromixing which provides a significant development in modern LOC and mTAS devices.

scholarly journals SYNTHESIS, CRYSTAL STRUCTURE AND HIRSHFELD SURFACE ANALYSIS OF 1-ACETYL-5-(2-METHYLPROPYL)-2-THIOXO-IMIDAZOLIDIN- 4-ONE

2018 ◽  
Vol 15 (29) ◽  
pp. 292-299
Author(s):  
C. CHACÓN ◽  
J. A. HENAO ◽  
J. JAMALIS ◽  
P. RIVAS ◽  
W. VELÁSQUEZ ◽  
...  
Keyword(s):  
Biological Effects ◽  
Biologically Active ◽  
Acid Mixture ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
Therapeutic Drugs ◽  
Hirshfeld Surfaces ◽  
Wide Range ◽  
Prostate Cancers

The hydantoin and thiohydantoin heterocycles are present in a wide range of biologically active compounds including therapeutic drugs for the treatment of seizures and anti-tumor compounds. Thiohydantoins, have also been used as anti-convulsant agents and are present in fungicides, herbicides and natural products. However, the principal current interest comes from the application of thiohydantoins for the treatment of prostate cancers. Structural characterization of hydantoin and thiohydantoin are important to comprehend their effect mechanisms because of their considerable biological effects. In this work a thiohydantoin derivative, 1-acetyl-5-(2-methylpropyl)-2-thioxo-imidazolidin-4-one (I), has been obtained by the reaction of 2-amino-4-methylpentanoic acid with KSCN in acetic anhydride-acetic acid mixture. The heterocyclic compound was characterized by FTIR, NMR, powder and single-crystal X-ray diffraction analysis. This compound crystallizes in the triclinic system, space group P-1 (Nº2), Z=4, with two independent molecules in the unit asymmetric. The thiohydantoin (I) forms one-dimensional hydrogen bonded chains, via a single hydrogen bond between the carbonyl oxygens and the amine ring N3 position, that run along [100] direction, with graphset motif C(6). The nature of intermolecular interactions has been analyzed through Hirshfeld surfaces and 2D fingerprint plots.

A High-Speed Disk Rotor Rig Design for Tip Aerothermal Research

2020 ◽  
Author(s):  
S. Lu ◽  
Q. Zhang ◽  
L. He
Keyword(s):  
High Speed ◽  
Cfd Simulation ◽  
Optical Measurement ◽  
Design Concept ◽  
System Level ◽  
Tip Leakage Flow ◽  
Component Level ◽  
Tip Leakage ◽  
Rotor Design ◽  
Wide Range

Abstract The relative casing motion can greatly vary the Over-Tip-Leakage (OTL) flow structure and thermal performance. The existing tip experimental research facilities include stationary linear cascade, cascade rigs with low speed moving belt, or high-speed rotor rigs are either not capable of reproducing the high relative casing Mach number, or extremely expensive and still difficult for optical measurement. This paper presents a highspeed disk rotor design which can simulate the high casing relative speed. The unique feature of this rig design concept is that it enables full optical access of the tip surface under the engine-representative OTL flow condition. In this paper, the feasibility of the design concept is demonstrated and assessed by RANS CFD simulation, both in component level and whole rig system level. The design idea demonstrated in this paper can be useful for a wide range of tip leakage flow studies.

Electrical Characterization of FCBGA Package Based on Measurement Approach for High-speed SOC Applications

2006 ◽  
Vol 3 (4) ◽  
pp. 216-225
Author(s):  
Ming-Kun Chen ◽  
Cheng-Chi Tai ◽  
Yu-Jung Huang
Keyword(s):  
Transmission Lines ◽  
High Speed ◽  
Flip Chip ◽  
Equivalent Circuit Model ◽  
Electrical Characterization ◽  
Time Domain Reflectometry ◽  
Electronic Market ◽  
Wide Range ◽  
The Time Domain

With high-speed computers and wireless communications system become more popular in the electronic market, these communication-oriented products require high packaging densities, clock rates and higher switching speeds over Gb/s. A multilayer flip-chip Ball grid array (FCBGA) package used for applications running at more than 1 Gb/s has been characterized in this work. Electrical characterization of the package becomes essential beyond 1 GHz considering that the interconnections on the package behave not only just as interconnections but also as transmission lines. In this paper, we present the measurement and simulation results for interconnection of an FCBGA package using the time domain reflectometry (TDR) method. Simulation and measurement results are compared to establish a proper equivalent circuit model of the FCBGA interconnections. The parasitics of the power network can be measured through TDR, vector network analyzer (VNA) and impedance analyzer (IA). The complete models generated in this work are targeted for high-speed system-on-chip (SOC) devices that have a wide range of uses across commercial electronic applications.

CFD Simulation for Turbulent Flow Past NACA4412 Aerofoil

2020 ◽  
Vol 12 (4) ◽  
Author(s):  
C. Manjunath ◽  
G.H. Somesha ◽  
Sekhar Majumdar
Keyword(s):  
Fluid Dynamics ◽  
Reynolds Number ◽  
Turbulent Flow ◽  
High Speed ◽  
Cfd Simulation ◽  
Measurement Data ◽  
Curvilinear Coordinates ◽  
Flow Past ◽  
Wide Range ◽  
Low Reynolds

The complex fluid dynamics of different flow situations at low Reynolds number for natural flying objects like birds and insects, needs to be clearly understood for arriving at an optimum design for sizes ranging from the small man-made ones to very large size high speed commercial aircrafts or the fighter aircrafts. Airfoil performance at low Reynolds numbers impacts the performance of a wide range of systems. Computational Fluid Dynamics (CFD) tools have been around for a couple of decades now. With the superfast growth of computing power, speed and accuracy of these mathematical tools have improved to a considerable extent. However, any CFD simulation employing turbulence models needs to be validated against reliable and accurate measurement data obtained from wind tunnels. The present work focuses on 2D numerical simulation of turbulent flow past a symmetric NACA4412 aerofoil, using C- grid topology, for a Reynolds number of 1 million and 3 million. The computation uses the CFD code RANS3D, an implicit, pressure-based finite volume type Reynolds averaged Navier-stokes solver in generalized non-orthogonal curvilinear coordinates.

Comparison of Experimental and Simulated Grain Flows

1995 ◽  
Vol 62 (1) ◽  
pp. 131-135 ◽  
Author(s):  
T. G. Drake ◽  
O. R. Walton
Keyword(s):  
High Speed ◽  
Particle Interaction ◽  
Three Dimensional ◽  
Particle Diameter ◽  
Interaction Model ◽  
Mean Velocity ◽  
Drag Forces ◽  
Physical Experiments ◽  
Walled Channel ◽  
Simulation Parameters

Fully three-dimensional computer simulations of identical spheres flowing in an inclined glass-walled channel only slightly wider than a particle diameter successfully reproduce profiles of mean velocity, bulk density, and particle rotations as well as profiles of fluctuating quantities measured from high-speed motion pictures of physical experiments. All simulation parameters are measured experimentally. Both full simulations of the geometry of the physical experiments and simulations using periodic boundary conditions in the downchute direction are used to gather micromechanical information. For these collision-dominated flows, quantitative predictions of the simulations are relatively insensitive to details of the particle-interaction model and particularly the particle stiffness, but are relatively sensitive to extraneous fluid drag forces and the chute geometry.

Microfabrication research at the National Submicron Facility

1983 ◽  
Vol 41 ◽  
pp. 86-89
Author(s):  
E.D. Wolf
Keyword(s):  
Integrated Circuits ◽  
Particle Physics ◽  
High Speed ◽  
New Technology ◽  
High Energy ◽  
High Energy Particle ◽  
New Science ◽  
Wide Range ◽  
Intermediate Domain ◽  
Circuit Function

Most microelectronics devices and circuits operate faster, consume less power, execute more functions and cost less per circuit function when the feature-sizes internal to the devices and circuits are made smaller. This is part of the stimulus for the Very High-Speed Integrated Circuits (VHSIC) program. There is also a need for smaller, more sensitive sensors in a wide range of disciplines that includes electrochemistry, neurophysiology and ultra-high pressure solid state research. There is often fundamental new science (and sometimes new technology) to be revealed (and used) when a basic parameter such as size is extended to new dimensions, as is evident at the two extremes of smallness and largeness, high energy particle physics and cosmology, respectively. However, there is also a very important intermediate domain of size that spans from the diameter of a small cluster of atoms up to near one micrometer which may also have just as profound effects on society as “big” physics.

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