183 research outputs found

    A Novel Nanoparticle Associated Polymer for Enhanced Oil Recovery in Harsh Conditions

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    Despite the high efficiency of polymer flooding as a chemical enhanced oil recovery (CEOR) technique, the low thermal stability and poor salt resistance of widely applied partially hydrolyzed polyacrylamide (HPAM) limited the application of this technique in oil reservoirs at harsh reservoir conditions of high–temperature and high–salinity (HTHS). These inadequacies of HPAM, result in the urge for environmentally friendly polymer with good viscosifying properties and a substantial effect on mobility ratio at HTHS reservoir condition. This research has introduced an assessment for the valorisation of a high acid value waste vegetable oil (WVO) into novel environmentally benign, thermo-responsive amphoteric nanocomposite for enhanced oil recovery (EOR) application at HTHS reservoir conditions. Two green reaction routes have been proposed to synthesize a novel oleic phenoxypropyl acrylate (OPA) thermosensitive monomer from high acid value WVO using different catalytic processes involve homogenous and heterogenous catalysts. A novel green copper-silica oxide/reduced graphene oxide (CuO-SiO2/RGO) multifunctional heterogeneous nanocatalyst derived from pomegranate peel extract has been synthesized and assessed for the direct conversion of high acid value WVO into OPA thermosensitive monomer via a single-step reaction. The prepared catalyst has been characterized using Fourier Transform Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX). Response surface methodology (RSM) via Box-Behnken Design (BBD) has been utilized to derive the optimum OPA monomer yield at minimum reaction conditions for each reaction route, where the influence of the process variables and their interactions on the OPA yield has been evaluated. The reactive acryloyl double bond in the synthesized OPA monomer has been copolymerized with acrylamide (AM), acrylacyloxyethyltrimethyl ammonium chloride (DAC) and 2-acrylamido-2-methylpropane sulfonic acid (AMPS) in presence of dimethylphenylvinylsilane via free radical emulsion polymerization for the synthesis of a novel thermo-responsive amphoteric green polymer functionalized silica nanocomposite (AGPC) for EOR application at HTHS conditions. RSM based on central composite design (CCD) has been utilized to tailor-make the feed composition of the synthesized AGPC nanocomposite. Further, the synthesized AGPC has been extensively characterized by different techniques. The results indicated that the optimal conditions of OPA monomer synthesis using 4- (dimethylamino)pyridine (DMAP) homogenous catalyst have been developed at 2- hydroxy-3-phenoxypropyl acrylate to methyl ester (HPA:FAME) molar ratio of 7.8:1, reaction temperature of 45 ºC, catalyst loading of 1.72 % (w/w) in 5.8 hours reaction time for 92.6 % OPA yield. However, for OPA monomer synthesis using CuO-SiO2/RGO nanocatalyst the optimal conditions have been developed at hydroxy-3-phenoxypropyl acrylate to WVO (HPA:WVO) molar ratio of 7.8:1, catalyst loading of 2.5 % (w/w) and reaction temperature of 94 ºC in 9.5 hours for 95.6 % OPA yield. The synthesized nanocomposite solution exhibited a pouncing thermo-thickening behaviour and superior viscosifying properties even at ultra-low polymer concentration of 400 ppm as the temperature increased from 25 to 100 ºC, with increasing salinity from 10,000 to 230,000 mg.L-1TDS as well as salt-free solutions. The nanocomposite solutions exhibit high resistance factor (Rf) and residual resistance factor (Rrf) values of 11.61 and 7.88, respectively at a low polymer concentration of 1000 ppm which proves its ability to improve the sweeping efficiency. Flooding experiments demonstrated that oil recovery factor reached 15.4 %, 22.6 % and 25 % using low nanocomposite concentrations of 400 ppm, 600 ppm and 1000 ppm, respectively evaluated under hostile conditions of 100 ºC and a salinity about 230,000 mg.L-1TDS. Therefore, this research offers a new direction for the synthesis of a novel green, high molecular weight thermo-responsive nanocomposite for EOR application at extreme harsh reservoir conditions via WVO valorisation

    Synthesis of green thermo-responsive amphoteric terpolymer functionalized silica nanocomposite derived from waste vegetable oil triglycerides for enhanced oil recovery (EOR)

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    Despite the high efficiency of polymer flooding as a chemical enhanced oil recovery (CEOR) technique, the low thermal stability and poor salt resistance of widely applied partially hydrolyzed polyacrylamide (HPAM) limited the application of this technique in oil reservoirs at harsh reservoir conditions of high–temperature and high–salinity (HTHS). These inadequacies of HPAM, result in the urge for an environmentally friendly polymer with good viscosifying properties and a substantial effect on mobility ratio at HTHS reservoir conditions. In this research, a high oleic acid waste vegetable oil (WVO) is utilized to synthesize a novel environmentally benign, thermo-responsive amphoteric nanocomposite for EOR applications at HTHS reservoir conditions. A green route transesterification reaction has been utilized to synthesize a novel thermo-sensitive monomer from WVO. The existence of unsaturated fatty acids isolated double bonds and acryloyl functional groups in the synthesized monomer has been confirmed using different characterization methods. The reactive acryloyl double bond in the synthesized monomer has been copolymerized with acrylamide, acrylacyloxyethyltrimethyl ammonium chloride, and 2-acrylamide-2-methylpropane sulfonic acid in presence of dimethylphenylvinylsilane via free radical emulsion polymerization. The synthesized nanocomposite has been characterized by FTIR, 1H NMR, SEM, EDX, TEM, and DLS. The thermal stability of the nanocomposite has been evaluated by TGA and DTA analysis. The results indicated that nanocomposite solution exhibited a pouncing thermo-thickening behaviour and superior viscosifying properties even at an ultra-low polymer concentration of 0.04 wt.% as the temperature increased from 25 to 100 °C, with increasing salinity from 10,000 to 230,000 ppm as well as salt-free solutions. Flooding experiments demonstrated that the oil recovery factor reached 15.4 ± 0.1% using low nanocomposite concentrations of 0.04 wt.%, 22.6 ± 0.3% using nanocomposite concentrations of 0.06 wt.% and 25 ± 0.2% using 0.1 wt.% nanocomposite concentrations evaluated under hostile conditions of 100 °C and salinity of about 230,000 ppm. This research offers a new direction for the synthesis of a novel green, high molecular weight thermo-responsive nanocomposite for EOR application at extremely harsh reservoir conditions via WVO valorization

    Synthesis and characterization of a novel amphoteric terpolymer nanocomposite for enhanced oil recovery applications

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    Water-soluble polymers are highly applied to increase the recovery from oil reservoirs. The application of these polymers in enhanced oil recovery (EOR) has some limitations regarding chemical, thermal and mechanical degradation at harsh reservoir condition. In this research, a novel stable terpolymer has been synthesised by preparing and grafting vinylbenzyl starch with poly (acrylamide/ acrylic acid/ acrylacyloxyethyltrimethyl ammonium chloride) in the presence of silica nanoparticles via free radical emulsion polymerization. Different stability investigations have been applied for the synthesised polymer including temperature, salinity and shear stability analyses at harsh conditions. The chemical structure of the novel polymer has been characterized using numerous methods including proton nuclear magnetic resonance (1H NMR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy and high-resolution transmission electron microscope (TEM). Thermal properties have been evaluated by thermal gravimetric analysis (TGA). The rheological properties have been studied at harsh reservoir conditions in terms of formation water salinity, temperature, and shear rate. The results have shown that the introduction of vinylbenzyl starch has significantly enhanced the thermal and chemical stability of the prepared polymer. Moreover, flooding experiments conducted on sandstone core have shown that the synthesised terpolymer can enhance the oil recovery up to 43% at polymer concentration of 3 g/L

    Assessment of the association of serum progranulin with autophagy in diabetic patients

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    Introduction: Progranulin (PGRN) has newly arisen as an important regulatory protein of glucose metabolism and insulin sensitivity. Progranulin expression is interrelated with lysosomal function strongly linked to autophagy pathway. We aimed to evaluate the correlation between PGRN protein and microtubule-associated protein light chain 3B (LC3B) expression level in diabetic patients. Material and methods: Blood samples of 70 type 2 diabetic Egyptian patients were provided for analysis of concentrations of serum progranulin and interleukin 6 (IL-6) using ELISA, and quantifying expression of LC3B RNA level using qPCR. A group of 20 healthy volunteers were also enrolled. Results: Serum levels of PGRN and IL-6 as well as LC3B gene expression levels were markedly higher in type 2 diabetic patients. Additionally, our study revealed a cut-off value of 18.14 ng/mL for progranulin serum level and 3.23 for LC3B expression level, with sensitivities of 83.6% and 75.4% and specificities of 83.8% and 58.3%, respectively. Circulating PGRN levels are positively correlated with body mass index (BMI), glucose concentration, and IL-6. Conclusion: Our results support the hypothesis that progranulin is introduced as a novel marker of chronic inflammatory response in type 2 diabetes that aggravates insulin resistance via activated autophagy, indicating the importance of this novel adipokine in the regulation of glucose metabolism and as a promising therapeutic target in the treatment of diabetes. Key words: diabetes; progranulin; autophagy; microtubule-associated proteins light chain 3B; interleukin

    A review on polymer flooding in enhanced oil recovery under harsh conditions

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    Polymer flooding is a commercially verified technology to enhance the recovery of residual oil from oil reservoirs. Polymers are used to increase the viscosity of the displacing phase. Accordingly, they resulted in a significant reduction in the mobility ratio between the water and oil. Due to the decrease in the mobility ratio, the sweep efficiency will significantly increase compared to water flooding. This paper aims to provide a comprehensive review on thermal and chemical stability and the rheological properties of various water-soluble polymers used in sandstone and carbonate reservoirs. The properties of conventional and novel water-soluble polymers applied in enhanced oil recovery (EOR) are discussed along with their limitations. Moreover, field and laboratory core flooding data of different water-soluble polymers are presented. This review covers current research studies on the application of polymer flooding to high-temperature and high-salinity reservoirs. It also provides recommendations for future work on synthesis of novel polymers with higher stability under harsh reservoir conditions

    The effectiveness of minimally-invasive corticotomy-assisted orthodontic treatment of palatally impacted canines compared to the traditional traction method in terms of treatment duration, velocity of traction movement and the associated dentoalveolar changes: A randomized controlled trial [version 1; peer review: 2 approved]

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    Objective: To evaluate the effectiveness of a minimally-invasive corticotomy-assisted treatment of palatally impacted canines (PICs) compared with the traditional method by evaluating treatment time, the velocity of movement, and the associated dentoalveolar changes. Materials and methods: Forty-six patients with palatally or mid-alveolar upper impacted canines were recruited and distributed into two groups: the corticotomy-assisted traction group (CAT group, mean age: 20.39±2.27 years) and the traditional treatment group (TT group, mean age: 20.26±2.17 years). The closed surgical approach was used in both study groups. The velocity of traction movement, traction duration and overall treatment duration were evaluated clinically. In addition, the bone support ratios and the amount of root resorption were assessed on cone-beam computed tomography (CBCT) images. Results: At the end of treatment, significant differences were found between the two groups regarding the velocity of traction movement, traction time, and overall treatment time (P<0.05). The mean velocity of traction movement in the CAT group was greater than the TT group (x velocity =1.15±0.35 mm/month; 0.70±0.33 mm/month, P=0.027, respectively). The duration of the active traction and the overall orthodontic treatment in the CAT group were significantly shorter than the TT group by 36% and 29%, respectively. The mean bone support ratios of the aligned canines did not differ significantly between the two groups (88% vs. 89% in the CAT and TT groups, respectively). No significant differences were found between the two groups regarding the mean amount of root resorption on the adjacent laterals (x resorption = 1.30±1.18 mm; 1.22±1.02 mm, P=0.612, in CAT and TT groups, respectively). Conclusions: The traction movement velocity of the palatally impacted canines can be increased using minimally-invasive corticotomy-assisted orthodontic treatment. The side effects of the acceleration procedure were minimal and almost similar to those of the traditional technique

    Revival-collapse phenomenon in the fluctuations of quadrature field components of the multiphoton Jaynes-Cummings model

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    In this paper we consider a system consisting of a two-level atom, initially prepared in a coherent superposition of upper and lower levels, interacting with a radiation field prepared in generalized quantum states in the framework of multiphoton Jaynes-Cummings model. For this system we show that there is a class of states for which the fluctuation factors can exhibit revival-collapse phenomenon (RCP) similar to that exhibited in the corresponding atomic inversion. This is shown not only for normal fluctuations but also for amplitude-squared fluctuations. Furthermore, apart from this class of states we generally demonstrate that the fluctuation factors associated with three-photon transition can provide RCP similar to that occurring in the atomic inversion of the one-photon transition. These are novel results and their consequence is that RCP occurred in the atomic inversion can be measured via a homodyne detector. Furthermore, we discuss the influence of the atomic relative phases on such phenomenon.Comment: 17 pages, 4 figure

    Perspectives for a mixed two-qubit system with binomial quantum states

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    The problem of the relationship between entanglement and two-qubit systems in which it is embedded is central to the quantum information theory. This paper suggests that the concurrence hierarchy as an entanglement measure provides an alternative view of how to think about this problem. We consider mixed states of two qubits and obtain an exact solution of the time-dependent master equation that describes the evolution of two two-level qubits (or atoms) within a perfect cavity for the case of multiphoton transition. We consider the situation for which the field may start from a binomial state. Employing this solution, the significant features of the entanglement when a second qubit is weakly coupled to the field and becomes entangled with the first qubit, is investigated. We also describe the response of the atomic system as it varies between the Rabi oscillations and the collapse-revival mode and investigate the atomic inversion and the Q-function. We identify and numerically demonstrate the region of parameters where significantly large entanglement can be obtained. Most interestingly, it is shown that features of the entanglement is influenced significantly when the multi-photon process is involved. Finally, we obtain illustrative examples of some novel aspects of this system and show how the off-resonant case can sensitize entanglement to the role of initial state setting.Comment: 18 pages, 9 figure
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