CARBONACEOUS NANOSIZED SURFACTANT CARRIERS AND OIL-INDUCED VISCOELASTIC FLUID FOR POTENTIAL EOR APPLICATIONS

This dissertation aims to advance the conventional tertiary oil recovery method, surfactant flooding process. Via injecting a finite slug of surfactant-only or mixture of surfactant/polymer solution into reservoir, surfactants are capable to dramatically reduce the residual oil/water interfacial tension (IFT) thus mobilize trapped oil. Despite the technical viability of surfactant flooding, this approach has some difficulties to be realized at large field scale, such as substantial adsorption loss, and unfavorable sweep efficiency of surfactant-only slug. This dissertation examined the feasibility of using carbonaceous nanoparticles, multiwalled carbon nanotube (MWNT), and carbon black as potential surfactant carriers in enhanced oil recovery. Stability of MWNT dispersion at high temperature high salinity levels, typical encountered in reservoir, as well as transport and fate of these stable nano-fluids in porous medium were first examined as a prerequisite for any field applications. MWNTs exhibited exceptional stability in 10 wt% brine by dispersing them with nonionic surfactant such as alkylphenol polyethoxylates with a large number of ethylene oxide (EO) groups. In the sandpack column test, a binary surfactant formulation, which consisted of a nonionic surfactant and an anionic surfactant in the proper ratios, exhibited an excellent capability to propagate MWNT, with 96% of the injected nanotubes recovered in the effluent. Chapter 2 presents the details of MWNT stability and transport in porous medium, which was previously published on Energy & Fuels. A successful surfactant delivery agent requires that surfactant ought to be released from the carriers once contact the target oil. In Chapter 3, batch adsorption tests indicated that competitive adsorption of surfactant on nanoparticles was beneficial to decrease adsorptive loss on Ottawa sand at equilibrium concentration below critical micelle concentration; microemulsions phase behavior proved spontaneous release of loaded surfactants from the treated MWNTs surfaces to oil/water interface; sand pack column tests carried out for an optimum surfactant formulation affirmed the advantage of adding nanoparticles into surfactant slug, as injection of MWNT-surfactant blend achieved faster and higher tertiary recovery than surfactant-only formulation. Chapter 3 was previously published on Fuel. An episode in the research of stable carbonaceous nanoparticles dispersion, reversed binary micellar interactions between anionic surfactant alpha olefin sulfonate (AOS) and nonionic surfactant nonylphenol polyethylene glycol ether (NPEs) were observed depending on the addition of electrolytes. In the absence of additional electrolytes, NPEs exhibited substantially higher activity in micelles than bulk solution; with growth of EO groups, shrinkage on the scale of synergistic interaction was evidenced. In contrary, with swamping amount of electrolytes, synergistic interactions enlarged with the rise of EO groups, and AOS activity in mixed micelles was found depending on both EO length and bulk mole fraction 〖(α〗_A). These findings are summarized in Chapter 4 and have been published on Colloids and Surfaces A: Physicochemical and Engineering Aspects. Chapter 5 discovered an oil-induced viscoelastic wormlike micellar solution. Wormlike micellar solution blends are important for industrial products where the high viscosity and elastic properties are exploited. However, wormlike surfactant micelles are extremely susceptible to oils; solubilization of paraffinic oils inside the micelle core leads to a disruption of wormlike micelles and loss of viscoelasticity. Oil-induced viscoelastic micellar fluid system is promising for various reservoir applications, such as proppant carrying fluids in hydraulic fracturing, and chemical slugs with built-in viscosity control in enhanced oil recovery. Chapter 6 presents some concluding remarks of this work and recommendations for the future studies

Comparative analysis of pre- and post-parasitic transcriptomes and mining pioneer effectors of Heterodera avenae

Additional file 2: Figure S2. Hierarchical layout of significantly enriched GOs of orthologous identified in H. avenae and 7 other nematodes. a Enriched GOs of orthologous present in H. avenae and all other 7 nematodes (Globodera pallida, Meloidogyne incognita, Meloidogyne hapla, Bursaphelenchus xylophilus, Caenorhabditis elegans, Pristionchus pacifics and Ascaris suum). b Enriched GOs of orthologous shared only by H. avenae and other plant-parasitic nematodes (G. pallida, M. incognita, M. hapla and B. xylophilus). c Enriched GOs of orthologous shared only by H. avenae and other sedentary plant-nematodes (G. pallida, M. incognita and M. hapla). d Enriched GOs of orthologous present only in cyst nematodes H. avenae and G. pallida. Light color represents significant enrichment (p < 0.1) and darker color represents more significant enrichment (p < 0.05)

Reactions of thiocarbamate, triazine and urea herbicides, RDX and benzenes on EPA Contaminant Candidate List with ozone and with hydroxyl radicals

Second-order rate constants of the direct ozone reactions (kO3,M) and the indirect OH radical reactions (kOH,M) for nine chemicals on the US EPA’s Drinking Water Contaminant Candidate List (CCL) were studied during the ozonation and ozone/hydrogen peroxide advanced oxidation process (O3/H2O2 AOP) using batch reactors. Except for the thiocarbamate herbicides (molinate and EPTC), all other CCL chemicals (linuron, diuron, prometon, RDX, 2,4-dinitrotoluene, 2,6-dinitrotoluene and nitrobenzene) show low reactivity toward ozone. The general magnitude of ozone reactivity of the CCL chemicals can be explained by their structures and the electrophilic nature of ozone reactions. The CCL chemicals (except RDX) are highly reactive toward OH radicals as demonstrated by their high kOH,M values. Ozonation at low pH, which involves mainly the direct ozone reaction, is only efficient for the removal of the thiocarbamates. Ozonation at high pH and O3/H2O2 AOP will be highly efficient for the treatment of all chemicals in this study except RDX, which shows the lowest OH radical reactivity. Removal of a contaminant does not mean complete mineralization and reaction byproducts may be a problem if they are recalcitrant and are likely to cause health concerns

Reactions of thiocarbamate, triazine and urea herbicides, RDX and benzenes on EPA Contaminant Candidate List with ozone and with hydroxyl radicals

Second-order rate constants of the direct ozone reactions (kO3,M) and the indirect OH radical reactions (kOH,M) for nine chemicals on the US EPA’s Drinking Water Contaminant Candidate List (CCL) were studied during the ozonation and ozone/hydrogen peroxide advanced oxidation process (O3/H2O2 AOP) using batch reactors. Except for the thiocarbamate herbicides (molinate and EPTC), all other CCL chemicals (linuron, diuron, prometon, RDX, 2,4-dinitrotoluene, 2,6-dinitrotoluene and nitrobenzene) show low reactivity toward ozone. The general magnitude of ozone reactivity of the CCL chemicals can be explained by their structures and the electrophilic nature of ozone reactions. The CCL chemicals (except RDX) are highly reactive toward OH radicals as demonstrated by their high kOH,M values. Ozonation at low pH, which involves mainly the direct ozone reaction, is only efficient for the removal of the thiocarbamates. Ozonation at high pH and O3/H2O2 AOP will be highly efficient for the treatment of all chemicals in this study except RDX, which shows the lowest OH radical reactivity. Removal of a contaminant does not mean complete mineralization and reaction byproducts may be a problem if they are recalcitrant and are likely to cause health concerns

Effect of overexpression of microRNA-124 on pulmonary vascular remodeling in rats with pulmonary arterial hypertension

Objective To evaluate the effect of overexpression of microRNA-124 （miR-124） on pulmonary vascular remodeling， and to unravel the potential mechanism in rats with pulmonary arterial hypertension （PAH）. Methods In the monocrotaline （MCT）-induced PAH rat models， intratracheal infusion of miR-124 carried by adeno-associated virus （AAV） was performed. The right ventricular systolic blood pressure （RVSP）， mean systolic arterial pressure and heart rate were recorded. The expression level of miR-124 in lung tissues of rats was detected by real-time quantitative PCR. The histological morphology of pulmonary arterioles was observed by van Gieson staining. The ratios of medium to outside diameter of pulmonary arterioles with vessel diameters in 25-50 μm and 51-100 μm were calculated. The expression levels of IL-6 and p-STAT3 protein in lung tissues were detected by Western blot. Results The expression level of miR-124 was down-regulated in pulmonary tissues of rats with PAH. RVSP was significantly decreased， the ratios of medium to outside diameter of pulmonary arterioles were significantly attenuated， and the expression levels of IL-6 and p-STAT3 proteins were significantly down-regulated by overexpression of miR-124. Conclusion AAV-mediated overexpression of miR-124 can significantly reduce RVSP and pulmonary vascular remodeling in rats with PAH， probably by down-regulating the expression levels of IL-6 and p-STAT3