Attrition in engineering programs continues to be an important issue for universities across the country. This study examined the connection between student performance in barrier courses and persistence in engineering. Quantitative results showed that high school academic experience, student behaviors (including study habits, work habits, coping strategies), students' perceptions about faculty behavior (including teaching styles and the "weedout" culture), the perceived culture of support in the engineering school, and motivation to succeed in engineering all impact students' performance in barrier courses. Qualitative results showed that motivation to succeed might be the reason why some students persist even when they "struggle" with barrier courses. 215
In surfactant flooding for enhanced oil recovery, adsorption of surfactants on the porous media of an oil reservoir is a major concern. It weakens the efficacy of the injected surfactant in reducing oil–water interfacial tension (IFT) and makes the oil recovery process uneconomical. Colloidal silica nanoparticles were found to adsorb at a lower rate than surfactant in porous media because of their charge density and high surface area. Silica nanoparticle surfaces with a negative surface charge are expected to adsorb onto the same active sites in the reservoir as anionic surfactant molecules used in enhanced oil recovery (EOR) applications. Experiments conducted in sandpack demonstrated that pre-treatment of the sandpack with silica nanoparticles at 80°C reduced surfactant adsorption by a factor of three when using artificial seawater as the injection fluid.
Tracer technology is a very efficient diagnostic tool for the oil and gas industry to obtain valuable information about reservoirs. The interpretation of tracers that have traversed the reservoir reveals reservoir characteristics such as inter-well connections, heterogeneities, and water movements that can be used to improve hydrocarbon recovery efforts. Commonly used tracers are radioactive elements and stable isotopes, chemicals, such as fluorescent dyes, and inorganic ions. Novel carbon quantum dots (CQDs)-based fluorescent tracers have been proposed for production and well monitoring. One-step electrochemical synthesis of CQDs from low molecular weight chemical precursors through electrochemical carbonization was developed. The doping of CQDs with heteroatoms such as nitrogen provides differentiated fluorescence emission signatures that can be used to monitor multiple stages of frac operations.
Tracers play an important role in the oil and gas industry by providing valuable information about reservoirs. In particular, tracers can help in mapping water movementfor determining information on water flooding that can be used to improve hydrocarbon recovery efforts. Some of the challenges associated with current chemical or dye-based tracer technology are thermal degradation over time, phase separation, and tedious detection processes. To overcome these drawbacks environmentally friendly, multicolor silica nanoparticles as tracershavebeen proposed toprovide simpler and faster detection through fluorescence spectroscopy.
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