Theoretical Estimation of Maximum Ellipsoidal Magnitude of a Low-Viscosity Droplet in a Parallel Gas Stream

2015 ◽  
Vol 31 (6) ◽  
pp. 727-732
Author(s):  
Z.-B. Wang ◽  
H.-F. Bai ◽  
J.-X. Xia ◽  
H.-Q. Zhong ◽  
Y.-C. Li

ABSTRACTMaximum ellipsoidal magnitude of the droplet is an important basic parameter for calculating drag force, droplets axial-velocity and dispersed-phase pressure gradient in an annular-mist pipe flow. An analytical correlation to predict the maximum ellipsoidal magnitude of a low-viscosity droplet in a parallel gas stream based on energy conservation and volume conservation. Stagnant pressure distribution on droplet surface is revised from Flachsbart's formula. The proposed correlation has clear physical meaning and easy to use. The correlation captures the deformation mechanism with an average absolute percent error of 9.53%. The effect of stagnant pressure distribution on the proposed correlation's accuracy is discussed.

Author(s):  
Alexander I. Kartushinsky ◽  
Efstathios E. Michaelides

Results from the mathematical modeling of gas-solid particle flow in an upward pipe flow performed in the framework of RANS are presented. The aim of the study is to implement an original model of closure for the transport equations of dispersed phase along with particles involvement into the turbulence motion into further developed the modeling description using the RANS approach. It allows the retention of the diffusive terms in both streamwise and radial directions. The numerical simulations show that the RANS method captures the main characteristics and overall behavior of the particle and gas-phase motion in the pipe.


2009 ◽  
Vol 25 (3) ◽  
pp. 253-267 ◽  
Author(s):  
Hidesada Kanda ◽  
Kenshuu Shimomukai

2018 ◽  
Vol 156 ◽  
pp. 08001
Author(s):  
Nita Aryanti ◽  
Richard A. Williams

Membrane emulsification is a technique utilising a novel concept of generating droplet ‘drop by drop’ to produce emulsions. The technique has several distinctive advantages over the conventional emulsification techniques.This paper concerns on the development of membrane emulsification (Rotating Membrane Reactor, RMR) which utilizes rotating tubular membrane to initiate droplet detachments. The RMR uses a rotating stainless steel tubular membrane with laser drilled pores (100 μm pore diameter) and a syringe pump to drive the dispersed phase through the membrane at a given flow rate. O/W formulations were prepared with low viscosity of paraffin wax, two types of emulsifiers, different membrane rotation rate and dispersed phase flow rate. The emulsion droplets exhibited a coefficient of variation of 9% and 81μm droplet size. In this research, the pore size/droplet size ratio could achieve 0.8. This value was below than other membrane emulsification processes. The effects of principal system operating parameters on both the average droplet diameter and droplet uniformity were discussed. In addition, a multiple (W/O/W) emulsion formulation was investigated as well.


Author(s):  
Edward D. De-Lamater ◽  
Eric Johnson ◽  
Thad Schoen ◽  
Cecil Whitaker

Monomeric styrenes are demonstrated as excellent embedding media for electron microscopy. Monomeric styrene has extremely low viscosity and low surface tension (less than 1) affording extremely rapid penetration into the specimen. Spurr's Medium based on ERL-4206 (J.Ultra. Research 26, 31-43, 1969) is viscous, requiring gradual infiltration with increasing concentrations. Styrenes are soluble in alcohol and acetone thus fitting well into the usual dehydration procedures. Infiltration with styrene may be done directly following complete dehydration without dilution.Monomeric styrenes are usually inhibited from polymerization by a catechol, in this case, tertiary butyl catechol. Styrene polymerization is activated by Methyl Ethyl Ketone peroxide, a liquid, and probably acts by overcoming the inhibition of the catechol, acting as a source of free radical initiation.Polymerization is carried out either by a temperature of 60°C. or under ultraviolet light with wave lengths of 3400-4000 Engstroms; polymerization stops on removal from the ultraviolet light or heat and is therefore controlled by the length of exposure.


Author(s):  
Fred E. Hossler

Preparation of replicas of the complex arrangement of blood vessels in various organs and tissues has been accomplished by infusing low viscosity resins into the vasculature. Subsequent removal of the surrounding tissue by maceration leaves a model of the intricate three-dimensional anatomy of the blood vessels of the tissue not obtainable by any other procedure. When applied with care, the vascular corrosion casting technique can reveal fine details of the microvasculature including endothelial nuclear orientation and distribution (Fig. 1), locations of arteriolar sphincters (Fig. 2), venous valve anatomy (Fig. 3), and vessel size, density, and branching patterns. Because casts faithfully replicate tissue vasculature, they can be used for quantitative measurements of that vasculature. The purpose of this report is to summarize and highlight some quantitative applications of vascular corrosion casting. In each example, casts were prepared by infusing Mercox, a methyl-methacrylate resin, and macerating the tissue with 20% KOH. Casts were either mounted for conventional scanning electron microscopy, or sliced for viewing with a confocal laser microscope.


Author(s):  
S. Lehner ◽  
H.E. Bauer ◽  
R. Wurster ◽  
H. Seiler

In order to compare different microanalytical techniques commercially available cation exchange membrane SC-1 (Stantech Inc, Palo Alto), was loaded with biologically relevant elements as Na, Mg, K, and Ca, respectively, each to its highest possible concentration, given by the number concentration of exchangeable binding sites (4 % wt. for Ca). Washing in distilled water, dehydration through a graded series of ethanol, infiltration and embedding in Spurr’s low viscosity epoxy resin was followed by thin sectioning. The thin sections (thickness of about 50 nm) were prepared on carbon foils and mounted on electron microscopical finder grids.The samples were analyzed with electron microprobe JXA 50A with transmitted electron device, EDX system TN 5400, and on line operating image processing system SEM-IPS, energy filtering electron microscope CEM 902 with EELS/ESI and Auger spectrometer 545 Perkin Elmer.With EDX, a beam current of some 10-10 A and a beam diameter of about 10 nm, a minimum-detectable mass of 10-20 g Ca seems within reach.


Author(s):  
S.L. White ◽  
C.B. Jensen ◽  
D.D. Giera ◽  
D.A. Laska ◽  
M.N. Novilla ◽  
...  

In vitro exposure to LY237216 (9-Deoxo-11-deoxy-9,11-{imino[2-(2-methoxyethoxy)ethylidene]-oxy}-(9S)-erythromycin), a macrolide antibiotic, was found to induce cytoplasmic vacuolation in L6 skeletal muscle myoblast cultures (White, S.L., unpubl). The present study was done to determine, by autoradiographic quantitative analysis, the subcellular distribution of 3H-LY237216 in L6 cells.L6 cells (ATCC, CRL 1458) were cultured to confluency on polycarbonate membrane filters (Millipore Corp., Bedford, MA) in M-199 medium (GIBCO® Labs) with 10% fetal bovine serum. The cells were exposed from the apical surface for 1-hour to unlabelled-compound (0 μCi/ml) or 50 (μCi/ml of 3H-LY237216 at a compound concentration of 0.25 mg/ml. Following a rapid rinse in compound-free growth medium, the cells were slam-frozen against a liquid nitrogen cooled, polished copper block in a CF-100 cryofixation unit (LifeCell Corp., The Woodlands, TX). Specimens were dried in the MDD-C Molecular Distillation Drier (LifeCell Corp.), vapor osmicated and embedded in Spurrs low viscosity resin. Ultrathin sections collected on formvar coated stainless steel grids were counter-stained, then individually mounted on corks. A monolayer of Ilford L4 nuclear emulsion (Polysciences, Inc., Warrington, PA) was placed on the sections, utilizing a modified “loop method”. The emulsions were exposed for 7-weeks in a light-tight box at 4°C. Autoradiographs were developed in Microdol-X developer and examined on a Philips EM410LS transmission electron microscope. Quantitative analysis of compound localization employed the point and circle approach of Williams; incorporating the probability circle method of Salpeter and McHenry.


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