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

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

Monitoring cellular Guanosine triphosphate (GTP) and GTP associated proteins

Guanosine-5'-triphosphate (GTP) is an essential molecule for cell survival and function. Although free GTP plays a crucial role in several cellular processes, most studies focus solely on the protein bound GTP and its association with cancer. Efficient methods for determining cellular GTP concentration are currently lacking. Chromatography or capillary electrophoresis are commonly utilized for separation and mass spectrometry (MS) for quantification of GTP in biological samples. For monitoring GTPases and their interactions with ligands, differential scanning fluorimetry, differential scanning calorimetry, or differential static light scattering are typically utilized. However, these methods either lack sensitivity or throughput. In this PhD project, the Protein-Probe method, based on a Eu3+-chelate peptide probe that interacts with the hydrophobic core of the protein, has been developed and applied for studying different factors that affect the thermal stability of small GTPases, such as inhibitors, buffer ions and nucleotides. Furthermore, the method was explored for a better understanding of the binding specificity of the recent Food and Drug Administration approved KRASG12C covalent inhibitors to RAS GTPases. Additionally, a novel dual-labeled Förster Resonance Energy Transfer (FRET)-based peptide probe was introduced and compared to the Protein-Probe method in the thermal stability assay. The FRET-Probe technique was also applied to determine the chemical stability of proteins with different chemical denaturants. For measuring cellular GTP level, a homogenous high throughput assay was developed to measure the amount of GTP in cells utilizing a highly GTP-specific antibody. The assay yielded comparable results to those obtained with CE/MS, demonstrating a similar level of accuracy, while also exhibiting a substantial enhancement in throughput. In conclusion, this thesis work aimed at developing novel and robust methods to address the current limitations in monitoring cellular GTP concentration and to study small GTPases. The focus of the study was free GTP, recognizing its essential role in various cellular processes.------ Guanosiini-5'-trifosfaatti (GTP) on välttämätön molekyyli solujen selviytymiselle ja toiminnalle. Vaikka vapaalla GTP:llä on ratkaiseva rooli useissa soluprosesseissa, suurin osa tutkimuksista keskittyy vain GTPaaseihin sitoutuneeseen GTP:hen ja sen linkittymisessä syövän kehittymiseen. Tällä hetkellä solun GTP-konsentraation määrittämiseksi ei ole tehokkaita menetelmiä. Käyttämällä kromatografiaa tai kapillaarielektroforeesia (CE) erotukseen ja massaspektrometriaa (MS) kvantifiointiin voidaan biologisten näytteiden GTP-pitoisuutta seurata, mutta se on melko työlästä. GTPaasien ja niiden vuorovaikutusten seurantaan käytetään tyypillisesti differentiaalista pyyhkäisyfluorimetriaa, differentiaalista pyyhkäisykalorimetriaa tai differentiaalista staattista valonsirontaa. Kaikilta näistä menetelmistä puuttuu kuitenkin herkkyys tai suorituskyky. Tästä syystä tämän opinnäytetyön tavoitteena oli kehittää uusia herkkiä ja toimintavarmoja menetelmiä GTP-pitoisuuden seurantaan ja GTPaasien tutkimiseksi uudesta näkökulmasta. Solujen GTP-tasojen mittaamiseksi kehitettiin homogeeninen tehoseulontaan yhteensopiva määritys käyttämällä GTP-spesifistä vasta-ainetta. Määritys tuotti samanlaisia tuloksia kuin vertailumenetelmänä käytetty CE/MS, mutta huomattavasti nopeammin ja helpommin. Tässä väitöskirjatyössä esiteltiin myös uusi kaksoisleimattu FRET-pohjainen peptidikoetin, jota käytettiin yhdessä aiemmin kehitetyn ”Protein-Probe” menetelmän kanssa. FRET-Probe tarjoaa saman korkean herkkyyden kuin Protein-Probe tekniikka, mutta se mahdollistaa proteiinin stabiilisuuden mittaamisen neutraalissa pH:ssa ja yhdessä vaiheessa. Protein-Probe menetelmää käytettiin pienten GTPaasien ja niiden lämpöstabiilisuuteen vaikuttavien tekijöiden tutkimiseen. Lisäksi kehitettyjä menetelmiä käytettiin FDA:n äskettäin hyväksymien kovalenttisten KRAS(G12C) inhibiittorien sitoutumisspesifisyyden, toiminnan ja resistenttiyden muodostumismekanismien tutkimiseen. FRET-Probe-tekniikkaa ei sovellettu ainoastaan proteiinien lämpöstabiilisuuden seurantaan, vaan sen osoitettiin soveltuvan myös proteiinien isotermaalisen kemiallisen stabiilisuuden seurantaan

Phytochemical and Biological Investigation of some Endemic Plants of Egypt with Development of a New HPTLC-β- Glucuronidase Inhibition Assay

St. Catherine region is located in Sinai Peninsula of Egypt, where two continents, Asia and Africa, are geographically connected. The area has a characteristic floristic diversity, within which a number of endemic plant species grow. So far, the biological and/or chemical analysis of many of these endemic species has not thoroughly reported. Accordingly, this study aimed at biological and chemical investigation of two plant species, P. boveana and A. pubescens, growing endemically in St. Catherine. The bacterial/ChE inhibition activities of P. boveana (leaf) and P. veris (flower) extracts were evaluated via HPTLC-EDA hyphenation. Identification of the active metabolites was based on the HPTLC-MS and NMR analysis. The active metabolites were identified as linoleic and linolenic acids (in P. veris) and unsubstituted flavone, 2'-methoxy-, 2'-hydroxy-, and 5,6,2',6'-tetramethoxyflavone (in P. boveana). In A. pubescens, the HPTLC-AChE inhibition activity screening of the 80% alcoholic extract of the plant led to determination of three active metabolites. Their characterization was based on the analysis of the collected mass and NMR data. Two of these metabolites were defined as newly isolated natural compounds; were elucidated to be 6-O-, 6'-O-di-trans-cinnamoylantirrhinoside and 5-O-, 6-O-difoliamenthoyl-antirrhinoside, while the previously known compound was determined as 6-O-foliamenthoyl-(6ꞌ-O-cinnamoyl)-antirrhinoside. In the third part of the study, a new HPTLC-β-glucuronidase inhibition assay was developed. The method was optimized and also verified using two botanical materials. The new hyphenation allowed, for the first time, the direct determination of the β-glucuronidase inhibitors present in complex mixtures. The fourth part of the study reported the HPLC-HRMS (/MS) analysis of the 80% alcoholic extract of P. boveana. A total of 25 metabolites have been tentatively identified as flavonoid compounds. The metabolites included, glycoconjugated flavonoids and flavonoid aglycones. Overall conclusion, the study supported the herbal-evidenced based medicine through establishment of important bioactivities to some plant species. It also confirmed the potential of chromatography/biological activity/chemical analysis hyphenation in evaluation of biological samples present in few amounts

Le marketing relationnel international des distributeurs : cas des hypermarchés français au Moyen-Orient

L'objectif de cette recherche est d'explorer comment les hypermarchés français orientent et développent leur stratégie marketing relationnelle dans le marché du Moyen-Orient. Il s'agit alors de comprendre si la standardisation personnalisée du marketing relationnel d'un point de vente favorise son intégration au marché local. Une étude qualitative a été menée auprès de vingt-deux directeurs d'hypermarchés français en Arabie Saoudite, aux Emirats Arabes Unis et en Egypte. Les résultats mettent en évidence que les enseignes françaises appliquent toutes le marketing relationnel domestique en y apportant de relatives adaptations au marché local. L'adoption d'une standardisation personnalisée s'avère être un compromis entre la volonté de maintenir la notoriété de l'enseigne et la nécessité de s'adapter à la demande locale

In Vivo Spectral Absorption Analysis Enabling the Classification of Pigmented Cutaneous Lesions: Investigating System Design and the Role of Faculative Melanin in the Spectral Determination of Skin Type Classification

A spectroradiometer was designed and built to record in vivo absorption characteristics of the lateral elbow. An analysis of variance of spectral characteristics between 400 and 1100 nanometers of faculative melanin to skin types one two and three was performed. The hypothysis that skin type could be differentiate by spectral recordings of in vivo faculative melanin was rejected. Further research is required to correlate constitutional melanin to skin type classification, in order to form a reference for pigmented cutaneous lesion classification

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

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