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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.
41

Surfactants and enhanced oil recovery

Pilc, J. January 1988 (has links)
A large number of commercial and some novel Brunel synthesised surfactants have been studied with a view to their potential usefulness for enhanced oil recovery (EOR) application. Ethoxylated phenols and their sulphonated derivatives were given especially high priority. The surfactants were well-characterised in order to understand their EOR potential. High pressure liquid chromatography, mass spectrometry, Raman spectrometry, nuclear magnetic resonance spectrometry and other quantitative techniques were used. Aspects of their behaviour (as single components and as blends with co-surfactants and co-solvents) which have been considered in terms of: (i) phase behaviour with brine and hydrocarbons (ii) adsorption onto various oxide surfaces (iii) interfacial properties such as surface tension, wetting, contact angles and viscosity (iv) stability Three different blends using sulphonated surfactants which: (i) produce a microeinulsion which is stable to high salinity brines over a large temperature range (ii) exhibit low adsorption onto reservoir rock (iii) interfacial tension as low as 10-2mNm-1 have been subsequently optimised. Core flooding tests carried out under reservoir conditions produced an additional 20% of the original-oil-in-place.
42

Factors affecting the performance of alkyl polyglucosides as potential adjuvants for agrochemicals

Hoyle, Edward R. January 1997 (has links)
No description available.
43

Neutron and X-ray scattering from interfaces

Su, Tsueu-Ju January 1996 (has links)
No description available.
44

The solution properties of hydrophobically modified guar gum derivatives

Young, Niall William George January 1997 (has links)
No description available.
45

Protein/polymer interactions investigated by surface plasmon resonance

Green, Rebecca J. January 1996 (has links)
No description available.
46

The pulmonary delivery of insulin

Nelson, Helen January 1996 (has links)
No description available.
47

Separation of mixed plastics by flotation

Chow, Ping-Sheng January 1996 (has links)
No description available.
48

Specular reflection from interfaces

Purcell, Isabella Pauline January 1994 (has links)
No description available.
49

Plan de negocios de una empresa productora y comercializadora de shampoo sólido para el mercado peruano / Business plan of a production and sell company of solid shampoo for the Peruvian market

Cruz Palacios, Erick Victor, De La Cruz Camargo, Jorge Alberto, Jeri Motta, Gioser Israel, Sotomayor Barzola, Guadalupe, Andrade Garro, Ernesto Alonso 27 September 2019 (has links)
El presente trabajo se enfoca en el desarrollo de un shampoo solido con ingredientes naturales, libre de insumos sintéticos y envase plástico. El principal problema encontrado es la ausencia de un shampoo natural que satisfaga las necesidades y brinde los beneficios requeridos por los consumidores peruanos, como problema secundario tenemos la contaminación ambiental producida por los plásticos de un solo uso. La actual oferta que se encuentra en el mercado se basa en shampoos comerciales elaborados con ingredientes sintéticos que aparentan brindar beneficios a los consumidores pero que a largo plazo lo que hacen es maltratar el cabello y cuero cabelludo. Todos los shampoos del mercado vienen contenidos en envases plásticos que, en su mayoría, al ser desechados. terminan en los mares y aportan a la contaminación ambiental. Por lo que se propuso como solución elaborar un shampoo que no presente envase de plástico y a su vez sea elaborado con ingredientes naturales tales como tensioactivos, aceites vegetales y aceites esenciales, los cuales aportaran sus propiedades naturales y brindaran los beneficios y resultados que los consumidores desean de manera eficiente y eficaz. En reemplazo del envase plástico se usarán cajas biodegradables, para ello el shampoo tendrá una apariencia sólida y no liquida. La marca se enfoca principalmente en comunicar a los consumidores los beneficios que brindan para el cabello y cuero cabelludo al tratarse de un producto elaborado con ingredientes naturales. / The present work focuses on the development of a solid shampoo with natural ingredients, free of synthetic inputs and plastic containers. The main problem encountered is the absence of a natural shampoo that meets the needs and provides the benefits required by Peruvian consumers, as a secondary problem we have the environmental pollution caused by single-use plastics. The current offer on the market is based on commercial shampoos made with synthetic ingredients that seem to provide benefits to consumers, but in the long term what they do is mistreat the hair and scalp. All shampoos on the market are contained in plastic containers that, for the most part, when discarded. They end up in the seas and contribute to environmental pollution. Therefore, it was proposed as a solution to develop a shampoo that does not have a plastic container and, in turn, is made with natural ingredients such as surfactants, vegetable oils and essential oils, which will provide their natural properties and provide the benefits and results that consumers want efficiently and effectively. In replacement of the plastic container biodegradable boxes will be used, for this the shampoo will have a solid and not liquid appearance. The brand mainly focuses on communicating to consumers the benefits they provide for hair and scalp, as it is a product made with natural ingredients. / Trabajo de investigación
50

A New Class of Nonionic Photosensitive Surfactants: Some Insights Concerning Conformations

Smith, Kenneth A., Hatton, T. Alan, Shang, Tiangang, Cicciarelli, Brad 01 1900 (has links)
We report on a new class of nonionic, photosensitive surfactants consisting of a polar di(ethylene oxide) head group attached to an alkyl spacer of between two and eight methylene groups, coupled through an ether linkage to an azobenzene moiety. Structural changes associated with the interconversion of the azobenzene group between its cis and trans forms as mediated by the wavelength of an irradiating light source cause changes in the surface tension and self-assembly properties. Differences in saturated surface tensions (surface tension at concentrations above the CMC) were as high as 14.4 mN/m under radiation of different wavelengths. The qualitative behavior of the surfactants changed as the spacer length changed, attributed to the different orientations adopted by the different surfactants depending on their isomerization states, as revealed by neutron reflection studies. The self-assembly of these photosensitive surfactants has been investigated by light scattering, small angle neutron scattering, and cryo-TEM under different illuminations. The significant change in the self-assembly in response to different illumination conditions was attributed to the sign change in Gaussian rigidity, which originated from the azobenzene photoisomerization. / Singapore-MIT Alliance (SMA)

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