• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2319
  • 1067
  • 583
  • 274
  • 103
  • 47
  • 38
  • 24
  • 23
  • 23
  • 18
  • 18
  • 11
  • 10
  • 8
  • Tagged with
  • 5202
  • 967
  • 823
  • 666
  • 594
  • 478
  • 409
  • 386
  • 368
  • 335
  • 311
  • 301
  • 275
  • 271
  • 263
  • 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.
331

Experimental Study of Solvent Based Emulsion Injection to Enhance Heavy Oil Recovery

Qiu, Fangda 2010 May 1900 (has links)
This study presents the results of nano-particle and surfactant-stabilized solvent-based emulsion core flooding studies under laboratory conditions that investigate the recovery mechanisms of chemical flooding in a heavy oil reservoir. In the study, bench tests, including the phase behavior test, rheology studies and interfacial tension measurement are performed and reported for the optimum selecting method for the nano-emulsion. Specifically, nano-emulsion systems with high viscosity have been injected into sandstone cores containing Alaska North Slope West Sak heavy oil with 16 API, which was dewatered in the laboratory condition. The experiment results suggest that the potential application of this kind of emulsion flooding is a promising EOR (enhanced oil recovery) process for some heavy oil reservoirs in Alaska, Canada and Venezuela after primary production. Heavy oil lacks mobility under reservoir conditions and is not suitable for the application of the thermal recovery method because of environmental issues or technical problems. Core flooding experiments were performed on cores with varied permeabilities. Comparisons between direct injection of nano-emulsion systems and nano-emulsion injections after water flooding were conducted. Oil recovery information is obtained by material balance calculation. In this study, we try to combine the advantages of solvent, surfactant, and nano-particles together. As we know, pure miscible solvent used as an injection fluid in developing the heavy oil reservoir does have the desirable recovery feature, however it is not economical. The idea of nano-particle application in an EOR area has been recently raised by researchers who are interested in its feature-reaction catalysis-which could reduce in situ oil viscosity and generate emulsion without surfactant. Also, the nano-particle stabilized emulsions can long-distance drive oil in the reservoir, since the nano-particle size is 2-4 times smaller than the pore throat. In conclusion, the nano-emulsion flooding can be an effective enhancement for an oil recovery method for a heavy oil reservoir which is technically sensitive to the thermal recovery method.
332

Preparation of Iron Nano-particles by Electrochemical Method

Hsiao, Yi-Hung 12 July 2005 (has links)
This thesis is to study on the preparation of iron nano-particles by electrochemical method in aqueous solution. The resultant particles are stabilized as a colloidal suspension by the use of cationic surfactants. The advantages include those high yield, low cost, and simple control of particle size by adjustment of the current density. It is revealed that current density, distance between electrodes, temperature, and surfactant concentration of aqueous solution play important roles on the preparation of nano-particles. The morphology, structure, composition, and optical properties of nano-particles are studied by Ultraviolet-Visible spectrophotometer (UV/Vis spectrophotometer), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The effect of particle size on the magnetic properties of nano-particles has been studied using superconducting quantum interference device (SQUID). According to the experimental results, the greater imposed current density is applied, the smaller the particle size is obtained. The absorption spectra of the particles exhibit that the characteristic peak of surface plasmon band is at 264 nm. The maghemite (£^-Fe2O3) phase is clearly confirmed by X-ray diffraction and TEM analysis. From the hysteresis loop studies, particles are paramagnetic at room temperature and they exhibited super-paramagnetic phenomenon. They become ferromagnetic at low temperature. The increase of the coercive force is due to the reduction of thermal vibration.
333

Synthesis, characterization and potential applications of FePt nanoparticles

Nandwana, Vikas. January 2009 (has links)
Thesis (Ph.D.)--University of Texas at Arlington, 2009.
334

I. Physical organic studies of an interfacial Diels-Alder reaction : II. A chemoselective approach to gold nanoparticles assembly and polymeric multilayer deposition on solid supports /

Chan, Eugene Wai Lun. January 2002 (has links)
Thesis (Ph. D.)--University of Chicago, Department of Chemistry, 2002. / Includes bibliographical references. Also available on the Internet.
335

Nanosize latex particles via miniemulsion polymerization /

Anderson, Christopher D. January 2002 (has links)
Thesis (Ph. D.)--Lehigh University, 2002. / Includes bibliographical references and vita.
336

Synthesis, characterization and properties of bioconjugated hydrogel nanoparticles

Debord, Justin, January 2004 (has links) (PDF)
Thesis (Ph. D.)--School of Chemistry and Biochemistry, Georgia Institute of Technology, 2004. Directed by Andrew Lyon. / Vita. Includes bibliographical references.
337

Bioprinted superparamagnetic nanoparticles for tissue engineering applications : synthesis, cytotoxicity assessment, novel hybrid printing system /

Buyukhatipoglu, Kivilcim. Clyne, Alisa Morss. January 2009 (has links)
Thesis (Ph.D.)--Drexel University, 2009. / Includes abstract and vita. Includes bibliographical references (leaves 160-177).
338

Environmentally benign mixing of nanoparticles

Sanganwar, Ganesh P. Gupta, Ram B. January 2009 (has links)
Dissertation (Ph.D.)--Auburn University, 2009. / Abstract. Includes bibliographic references.
339

Particle engineering for the formulation of smart functional fluids : novel synthesis, processing and comparative analysis of magnetic nanoparticles and fluids /

Sinha, Kaustav. January 2009 (has links)
Thesis (Ph. D.)--University of Nevada, Reno, 2008. / "December 2008." Includes bibliographical references. Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2009]. 1 microfilm reel ; 35 mm. Online version available on the World Wide Web.
340

Analysis of particulate matter concentration and size distribution in heavy-duty vehicle exhaust emissions

Xu, Zhuyun. January 2001 (has links)
Thesis (M.S.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains xi, 133 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 129-133).

Page generated in 0.0444 seconds