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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

CO2 Capture on Porous Adsorbents Containing Surface Amino Groups

Esam, Odette Amana 01 December 2013 (has links) (PDF)
The potential impact of carbon dioxide as a major source of global warming has led to extensive research in order to mitigate the greenhouse effect. In this work, four adsorbents were synthesized and studied. The adsorbents were obtained by grafting and sol-gel of amino-containing molecules such as bis[3-(trimethoxysilyl)propyl]amine as monoamine and [3-(2-aminoethylamino)propyl]- trimethoxysilane as diamine on the surface of silica gel. CO2 passed through adsorbents at room temperature for its capture, then desorbed at moderate heating, and stored in the form of insoluble BaCO3. The adsorbent synthesized by sol-gel synthesis was found to be more efficient due to its high content of amino groups. A demonstration experiment on reversible adsorption of CO2 on mesoporous modified silica gel was developed. This experiment visualizes a technology of post-combustion CO2 sequestration from industrial emission gases and its storage.
2

Research of Two Types of Slippery Surfaces: Slippery Polydimethylsiloxane Elastomers and Polyelectrolyte Multilayers Slippery Surfaces

Liu, Yawen 14 September 2018 (has links)
No description available.
3

FACILE AND FAST FABRICATION OF FUNCTIONAL THIN FILMS VIA POLYELECTROLYTE LAYER-BY-LAYER ASSEMBLY

Cho, Szu-Hao 26 August 2020 (has links)
No description available.
4

Implicit representation of inscribed volumes

Sahbaei, Parto 01 May 2017 (has links)
We present an implicit approach for constructing smooth isolated or interconnected 3-D inscribed volumes which can be employed for volumetric modeling of various kinds of spongy or porous structures, such as volcanic rocks, pumice stones, Cancellus bones *, liquid or dry foam, radiolarians, cheese, and other similar materials. The inscribed volumes can be represented in their normal or positive forms to model natural pebbles or pearls, or in their inverted or negative forms to be used in porous structures, but regardless of their types, their smoothness and sizes are controlled by the user without losing the consistency of the shapes. We introduce two techniques for blending and creating interconnections between these inscribed volumes to achieve a great flexibility to adapt our approach to different types of porous structures, whether they are regular or irregular. We begin with a set of convex polytopes such as 3-D Voronoi diagram cells and compute inscribed volumes bounded by the cells. The cells can be irregular in shape, scale, and topology, and this irregularity transfers to the inscribed volumes, producing natural-looking spongy structures. Describing the inscribed volumes with implicit functions gives us a freedom to exploit volumetric surface combinations and deformations operations effortlessly / Graduate
5

ENERGY EFFICIENCY AND FLUX ENHANCEMENT IN MEMBRANE DISTILLATION SYSTEM USING NOVEL CONDENSING SURFACES

Yashwant S Yogi (9525965) 16 December 2020 (has links)
<p>The water crisis is increasing with every passing day due to climate change and increase in demand. Different desalination methods have been developed over the years to overcome this shortage of water. Reverse Osmosis is the most widely used desalination technology, but cannot treat many fouling-prone and high salinity water sources. A new desalination technology, Membrane distillation (MD), has the potential to purify wastewater as well as highly saline water up to a very high purity. It is a thermal energy-driven desalination method, which can operate on low temperature waste heat sources from industries, powerplants and renewable sources like solar power. Among the different configurations of MD, Air Gap Membrane Distillation (AGMD) is the most versatile and flexible. However, the issue that all MD technology, including AGMD face, is the low energy efficiency. Different sections of AGMD system have been modified and improved over the years through consistent research to improve its energy efficiency, but one section that is still new and unexplored, and has a very high potential to improve the energy efficiency of AGMD, is the ‘air gap’.</p><p> </p><p> </p><p>The aim of this research is to tap into the potential of the air gap and increase the energy efficiency of the AGMD system. It is known that decreasing the air gap thickness improves the energy efficiency parameter called Gained output ratio (GOR) to a great extent, especially at very small air gap thickness. The minimum gap thickness that maximizes the performance is smaller than the current gap thicknesses used. But it is difficult to attain such smaller air gap thickness (< 2mm) without the constant risk of flooding. Flooding can be prevented, and smaller air gap thickness can be achieved if instead of film wise condensation on the condensing surface, a different condensation flow regime is formed. This study tests different novel condensing surfaces like Slippery liquid infused porous surfaces (SLIPS) and Superhydrophobic surfaces (fabricated with different methods) inside the AGMD system with a goal of attaining smaller air gap thickness and improve the performance of AGMD system for the first time. The performance of these surfaces is compared with plain copper surface as well as with each other. Finally, numerical models are developed using the experimental data for these surfaces.</p><div><div><div> </div> </div> </div>

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