Nanoparticle dispersion flow for enhanced oil recovery using micromodels

textThe injection of nanoparticles is a promising and novel approach to enhancing oil recovery in depleted fields. Nanoparticles have one dimension that is smaller than 100 nm and have many unique properties that are useful when it comes to oil recovery. Their small size and the ability to manipulate particle properties are a couple of the advantageous properties. The small size of nanoparticle allows them to easily pass through porous media. Manipulating nanoparticle properties allows for wettability modifications or controlled release of chemicals at a precise location in the formation. Injection of nanoparticle dispersions for secondary or tertiary recovery in corefloods has yielded positive results. Field tests using nanoparticles have also yielded positive results with increased oil recovery. While there has been a sizable amount of work related to corefloods, limited investigation has been reported using micromodels. Micromodels are valuable because they allow for pore scale viewing of the oil recovery, which is not possible with corefloods. In this research both polydimethylsiloxane (PDMS) and glass microfluidic devices were fabricated to test the EOR potential of different types of nanoparticles. Much of the work described in this thesis involved the use of a dead-end pore geometry to trap oil. First the pore space was filled with oil and then waterflooded. This left some oil trapped in the dead-end pores. PDMS micromodels proved difficult to trap oil in the dead-end pores; because of this glass micromodels were tested. After trapping oil, a nanoparticle dispersion was injected into the pore space to test the potential of the dispersion to reduce the residual oil saturation in the dead-end pores. The nanoparticle dispersion was injected at different flow rates (1 [mu]l/hr to 50 [mu]l/hr) to test the effect of flow rate on residual oil recovery.Petroleum and Geosystems Engineerin

Pyrolysis oil utilization in 50KWE gas turbine

The concept of using pyrolysis oil (PO) derived from biomass via a fast pyrolysis route for power and heat generation encounters problems due to an incompatibility between properties (physical and chemical) of bio-oil and gas turbines designed for fossil fuels. An extensive research has been performed on the production and improvement of pyrolysis oil but only few investigations were carried out on its utilization. The latter have shown a major difference in behavior of pyrolysis oil compared to fossil fuels during combustion processes. In this work, pyrolysis oil is co-fired with diesel in a 50 kWe gas turbine operating in idle mode. Stable mixtures with up to 20 wt.% of pyrolysis oil and diesel fuel were produced with utilization of a surfactant agent. To prevent feeding line deterioration due to acidic character of pyrolysis oil, a stainless steel nozzle was employed. Furthermore, the fuel emulsion was preheated up to maximum temperature of 80 oC in order to reduce the effect of high viscosity on the atomization process. Diesel distillate #2 was used as a reference fuel for a comparison of gas turbine performance and emissions with various PO content in the blends. During the combustion investigations, the amount of pyrolysis oil was gradually increased with simultaneous decrease of preheating temperature. In all investigated cases, the gas turbine was running stable at its maximum rotational speed (RPM). The CO level resulting from the study with different blends was generally slightly higher in relation to the diesel distillate fuel. NO emissions were in the range of few ppm and almost no detectable with common gas analyzing equipment. After a few hours of continuous operation, there were no signs of deterioration or contaminations inside the combustor. The study shows that pyrolysis oil gradually can be introduced in the market of fossil fuels and benefit to green power generation

Imaging of the Lymphatic Vessels for Surgical Planning:A Systematic Review

Background Secondary lymphedema is a common complication after surgical or radiotherapeutic cancer treatment. (Micro) surgical intervention such as lymphovenous bypass and vascularized lymph node transfer is a possible solution in patients who are refractory to conventional treatment. Adequate imaging is needed to identify functional lymphatic vessels and nearby veins for surgical planning. Methods A systematic literature search of the Embase, MEDLINE ALL via Ovid, Web of Science Core Collection and Cochrane CENTRAL Register of Trials databases was conducted in February 2022. Studies reporting on lymphatic vessel detection in healthy subjects or secondary lymphedema of the limbs or head and neck were analyzed. Results Overall, 129 lymphatic vessel imaging studies were included, and six imaging modalities were identified. The aim of the studies was diagnosis, severity staging, and/or surgical planning. Conclusion Due to its utility in surgical planning, near-infrared fluorescence lymphangiography (NIRF-L) has gained prominence in recent years relative to lymphoscintigraphy, the current gold standard for diagnosis and severity staging. Magnetic resonance lymphography (MRL) gives three-dimensional detailed information on the location of both lymphatic vessels and veins and the extent of fat hypertrophy; however, MRL is less practical for routine presurgical implementation due to its limited availability and high cost. High frequency ultrasound imaging can provide high resolution imaging of lymphatic vessels but is highly operator-dependent and accurate identification of lymphatic vessels is difficult. Finally, photoacoustic imaging (PAI) is a novel technique for visualization of functional lymphatic vessels and veins. More evidence is needed to evaluate the utility of PAI in surgical planning.</p

Pb-207 chemical shielding in lead molybdate and lead chloride: The effects of temperature and lattice expansion

The analysis of heavy-metal solids with NMR spectroscopy provides a means of investigating the electronic environment through the dependence of the chemical shift on structure. We have investigated the relation of the 207Pb NMR isotropic chemical shift, span, and skew of a series of solid Pb(II) compounds to lattice parameters. Complementary relativistic spin−orbit density functional calculations on clusters such as PbI64- that model the local environment in the dihalides show a dependence of NMR properties on the local structure in good agreement with experimental results

Metatarsophalangeal joint stability: A systematic review on the plantar plate of the lesser toes

Background: Instability of the metatarsophalangeal (MTP) joints of the lesser toes (digiti 2-5) is increasingly being treated by repair of the plantar plate (PP). This systematic review examines the anatomy of the plantar plate of the lesser toes, and the relation between the integrity of the plantar plates of the lesser toes and lesser MTP joint stability. Methods: The databases of Embase.com, Medline (Ovid), Web of Science, Scopus, Cochrane, Pubmed not medline, Cinahl (ebsco), ProQuest, Lilacs, Scielo and Google Scholar were searched in June 2015 from inception. Studies were included if they were in English, contained primary data, and had a focus on plantar plate anatomy of the lesser toes or on the relationship between integrity of the plantar plate and MTP joint (in)stability. Study characteristics were extracted into two main tables and descriptive anatomical and histological data were summarized into one schematic 3D drawing of the plantar plate. Results: Nine studies were included in this systematic review, of which five addressed plantar plate anatomy as such and four focused directly and indirectly on plantar plate integrity related to MTP joint stability. Conclusion: This is the first systematic review regarding plantar plate anatomy related to MTP joint stability of the lesser toes. This review iterates the importance of plantar plate anatomy and integrity for MTP joint stability, and it delineates the lack of primary data regarding plantar plate anatomy of the lesser toes and MTP joint stability