Nanofluids (dispersion of nanoparticles in a base fluid) have been suggested as promising agents in subsurface industries including enhanced oil recovery. Nanoparticles can easily pass through small pore throats in reservoirs formations; however, physicochemical interactions between nanoparticles and between nanoparticles and rocks can cause a significant retention of nanoparticles. This study investigated the transport, attach, and retention of silica nanoparticles in core plugs. The hydrophilic silica nanoparticles were injected into limestone core as nanofluid of different nanoparticles size (5 nm, and 20 nm), concentration (0.005 – 0.1 wt% SiO2), and base fluid salinity (0 – 3 wt% NaCl) at different temperatures (23, and 50 °C). Deposition and transport of nanoparticles were measured via nanoparticle concentration of effluent fluid, and energy distractive spectroscopy (EDS) measurement on the limestone core. It was found that silica nanoparticles dispersed in brine (NaCl) solutions are increasingly retained in limestone core as the solution ionic strength increases. On the other hand, less significant retention was measured when the nanoparticles were dispersed in DI water. The EDS measurements also reported the same trend of increased nanoparticles retention with salinity due to larger aggregates that result from the screening effect of the electrolyte on repulsive forces between nanoparticles. Thus, the observed change in surface wettability from oil to water-wet and the increase in oil production that reported in many core flooding laboratory studies are mainly related to the high adsorption rate of hydrophilic silica nanoparticles on carbonate surfaces.
Bac kground: The transfer of the tibialis posterior tendon to the anterior aspect
of the ankle not only replaces the function of the paralyzed muscles, but also
removes the deforming force on the medial aspect of the foot.
Objec t i ves : In this study, we evaluated patients who underwent tibialis
posterior tendon transfer for the treatment of foot drop, and comparison through
interosseous membrane route versus anterior to lower tibia route of tibialis
posterior tendon transfer, with evaluation of the results according to carayon
criteria
Methods: Nine patients with foot drop secondary to different causes treated with
tibialis posterior tendon transfer from January 2011 to January 2012 were
followed up for a
Esterification reaction is most important reaction in biodiesel production. In this study, oleic acid was used as a suggested feedstock to study and simulate production of biodiesel. Batch esterification of oleic acid was carried out at operating conditions; temperature from 40 to 70 °C, ethanol to oleic acid molar ratio from 1/1 to 6/1, H2SO4 as the catalyst 1 and 5% wt of oleic acid, reaction time up to 180 min. The optimum conditions for the esterification reaction were molar ratio of ethanol/oleic acid 6/1, 5%wt H2SO4 relative to oleic acid, 70 °C, 90 min and conversion of oleic 0.92. The activation energy for the suggested model was 26625 J/mole for forward reaction and 42189 J/mole for equilibrium constant. The obtained results s
... Show MoreThe study aimed to reach the best rating for the views and variables in the totals characterized by qualities and characteristics common within each group and distinguish them from aggregates other for the purpose of distinguishing between Iraqi provinces which suffer from deprivation, for the purpose of identifying the status of those provinces in the early allowing interested parties and regulators to intervene to take appropriate corrective action in a timely manner. Style has been used cluster analysis Cluster analysis to reach the best rating to those totals from the provinces that suffer from problems, where the provinces were classified, based on the variables (Edu
... Show MoreThe organizational structure of relations between states is among the main features that distinguished the twentieth century as the era of international organization, especially after the increase in the number of political units after World War II in which regionalism was crystallized as a phenomenon. It is not modern, as there are many blocs such as the European Union that have developed in it, the idea of regional bloc is prominent, especially in Europe, as it emerged after a controversy revolved around what was called globalism in the face of Globalism vs. Regionalism. Regional, as the proponents of the global orientation saw the establishment of a global organization that includes all countries, as the best way to achieve inte
... Show MoreThe Main Outfall drain pumping station in Nassiriyah is an important part in operation system of the Main Outfall Drain (MOD) where it reduces the water levels in the U/S area of its and converted through Syphon freely under the Euphrates, its consists of several parts: U/S Basin, Station Building which contains 12 pumps, and Head Basin with Syphon, This station suffers from high levels especially in D/S area due to the current situation which is represented by establishing of dyke with pipes on MOD which located at 24 km from D/S of pumping station and Al-Khamisiyah Canal which located at 2.3 km from the U/S of dyke which feeds(Al Hammar Marsh) during drought season, several scenarios were adopted in order to expl
... Show MoreBackground: Sonographic examination is an important tool in assessment of normal and abnormal cervical lymph nodes. The aim of the study is to assess the distribution and the characteristic features of normal cervical lymph nodes in a sample of Syrian population. Materials and Methods: Fifty healthy Syrian subjects (25 men and 25 women) with an age of 20 -60years old, who had their cervical lymph nodes examined by ultrasound. Three hundred and two lymph nodes were detected. Lymph nodes were evaluated for their number, size, site, echogenic hilus, shape, as well as for the border sharpness. The subjects were categorized by age into four groups, (20 -30, 31 - 40 , 41 - 50 , 51- 60 years ). Statistical analysis of data was done using SP
... Show MoreMolecular interactions between 2-isopropenylnaphthalene-methacrylic acid (IPNMA) block copolymer( as a model for water- soluble polymer) and methanol at several temperatures were studied using fluorescence techniques , Fluorescence spectrum for (IPNMA) exhibits two emission bands at around 342 nm and 387 nm corresponding to the monomer and the excimer bands , respectively .The fluorescence spectra of dilute solution of (IPNMA) in methanol were recorded in temperature range of 8- 45?C . Plot of the excimer to monomer intensity ratio Ie/Im versus temperature was obtained, which shows double lines with positive slopes crossing at 25?C , the increasing of slope value above this temperature is s
... Show MoreAbstract:
The problem of poverty is one of the most important development challenges facing developing countries including Sudan for several decades. Although many efforts have been made to reduce poverty, however, its rates are increasing, and public policies adopted by the government in this regard remain elusive in achievinging its main objectives or making any significant progress. The purpose of the present study is to analyse poverty in Sudan by identifying its measurement, causes and the factors that have contributed to the increasing poverty rates over the past two decades. Also this study aims at investigating the interim poverty reduction strategy in Sudan as well as evaluates that strategy throug
... Show Moreشهدت العالم منذ نهايات القرن الماضي وبدايات القرن الواحد والعشرين تطورات دراماتيكية على صعيد الادبيات التنموية ، اذ تحولت التنمية من المفهوم التقليدي الذي اهتم بالنمو الاقتصادي الى رؤية جديدة هي رؤية التنمية البشرية ومن ثم الى التنمية المستدامة التي اعطت للتنمية البعد الانساني وجعلت من مشكلات واحتياجات البشر منطلق لها لتحويل الفرد والمجتمع الى مرحلة جديدة تضمن له العيش الكريم وتحقق معه
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