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Full-Text Articles in Engineering
Pure And Binary Adsorption Equilibrium Of Nitrogen And Oxygen In Lilsx Zeolite, Himabindu Gandra
Pure And Binary Adsorption Equilibrium Of Nitrogen And Oxygen In Lilsx Zeolite, Himabindu Gandra
ETD Archive
Chemical products are made by combination of processes that includes synthesis, separation and purification. Separation processes comprises a large portion in these industries and are considered to be critical as most of the applications in chemical industries involves mixtures. Traditional separation methods such as distillation, evaporation, drying etc., requires high energy. For example, air separation to produce nitrogen and oxygen was previously practiced by cryogenic distillation that involves high pressure units and large energy requirement. On other hand, adsorption processes utilize less energy resources and is unique among separation methods. The phase separation is achieved by the existence of a …
Evaluation Of Mass Transfer Rate In Column Of Small Lilsx Particles, Mihikumar S. Patel
Evaluation Of Mass Transfer Rate In Column Of Small Lilsx Particles, Mihikumar S. Patel
ETD Archive
Air separation using zeolite based adsorption processes is a widely-studied topic. Proper process modeling is a key requirement to simulate the process. Conventional process modeling for air separation is designed for large scale adsorption processes using a long cycle time. However, advanced technology now permits to use of a short cycle time using small particles, which significantly reduces the size of the process.
Traditional process models were mostly developed for large particles (dp > 1.5 mm). Typically, it is safely assumed that intra particle diffusion controls the rate of the process while axial dispersion has a much smaller effect. This is …
Effect Of Convection Associated With Cross-Section Change During Directional Solidification Of Binary Alloys On Dendritic Array Morphology And Macrosegregation, Masoud Ghods
ETD Archive
This dissertation explores the role of different types of convection on macrosegregation and on dendritic array morphology of two aluminum alloys directionally solidified through cylindrical graphite molds having both cross-section decrease and increase. Al- 19 wt. % Cu and Al-7 wt. % Si alloys were directionally solidified at two growth speed of 10 and 29.1 µm s-1 and examined for longitudinal and radial macrosegregation, and for primary dendrite spacing and dendrite trunk diameter.
Directional solidification of these alloys through constant cross-section showed clustering of primary dendrites and parabolic-shaped radial macrosegregation profile, indicative of “steepling convection” in the mushy-zone. The degree …
Influence Of Cross-Section Change During Directional Solidification On Dendrite Morphology, Macrosegregation And Defect Formation In Pb-6 Wt Sb Alloy, Claudine Lacdao
Influence Of Cross-Section Change During Directional Solidification On Dendrite Morphology, Macrosegregation And Defect Formation In Pb-6 Wt Sb Alloy, Claudine Lacdao
ETD Archive
The purpose of this research is to examine the dendrite array morphology, macrosegregation, and defect formation caused by the fluid flow at the abrupt cross-section changes during directional solidification of Pb-6% Sb alloy. Four 24-cm long cylindrical alloy samples were directionally solidified in graphite crucibles: two having a constant diameter (9-mm) grown at 10.4 and 63.1 μm s-1 , one having an abrupt cross-section decrease (from 12.7 to 6.35 mm) and one having an abrupt increase (from 6.35 to 12.7 mm) by pulling down the alloy containing cylindrical graphite crucibles from the upper hot-zone of a stationary vertical furnace into …
Evaluation Of A Microfluidic Mixer Utilizing Staggered Herringbone Channels: A Computational Fluid Dynamics Approach, Brian Hama
ETD Archive
Microfluidic platforms offer a variety of advantages including improved heat transfer, low working volumes, ease of scale-up, and strong user control on parameters. However, flow within microfluidic channels occurs at low Reynolds numbers, which makes mixing difficult to accomplish. Adding V-shaped ridges to channel walls, a pattern called the staggered herringbone design (SHB), might alleviate this problem by introducing transverse flow patterns that enable enhanced mixing. However, certain factors affecting the SHB mixer’s performance remain largely unexplored.
In this work, a microfluidic mixer utilizing the SHB geometry was developed and characterized using computational fluid dynamics based simulations and complimentary experiments. …
Effect Of Surface Oxidation On The Mechanics Of Carbon Nanotube Laden Interfaces, William Daniel Ivancic
Effect Of Surface Oxidation On The Mechanics Of Carbon Nanotube Laden Interfaces, William Daniel Ivancic
ETD Archive
Single and multi-walled carbon nanotubes (SWCNT & MWCNT) have been studied over the past three decades because of their excellent properties, including their mechanical strength and large electrical and thermal conductivities. Incorporating CNTs into phases necessary for use in consumer or industrial products has been challenging because of strong attractive interactions, heterogeneity, and lack of separation techniques for these nanomaterials. Moreover, there are further challenges incorporating CNTs into multiphase materials because of the many remaining open questions regarding the properties of an interface with CNTs adsorbed or nearby. In the present work, the mechanics and microstructure of a water/air interface …