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.
The researcher dealt with the importance of striking proverbs in the Holy Qur’an and their uses and benefits in Islamic education and ethics and between the types of proverbs, so it emerged through the study the following things that the proverbs are of three types: authorized, latent, and transmitted, and it has been shown through the current study that the proverb has conditions that the proverb is not valid except There are five: (realism, clarity, environmental, meaning injury, and good pronunciation). If the example violates these conditions, it is not an example. This study showed that proverbs have a prominent role in persuasion, argument, statement, education, clarity, approximation, education, refinement, correct belief, etc.
... Show MoreThe present study aims to show the importance of ESL reading ability in acquiring English as a second language. The study involves 92 college students (males and females) from the Department of English at Nizwa College of Applied Sciences, Sultanate of Oman. They represent two groups, the foundation year students and the first year English majors. A number of tests were used to measure students’ overall proficiency in English as well as their reading ability (i.e., the ability to contribute to the main idea of the text, scanning, skimming, to derive word meanings from context, to use a dictionary to find meanings, definitions, to identify prefixes, antonyms and synonyms). Students’ ability to read was correlated to their proficiency
... Show MoreVerapamil Hydrochloride (VH) has been determined spectrophotometrically by using Methyl Orange (MO). In our previous researches MO was used for determination of Mexiletine Hydrochloride [1]. The method was based on complexation between (MO and VH). After shaking and diluting the complex solution with D.W, the pH was adjusted with NaOH and HCl to pH 4. The colored complex formed between VH and the reagents were transferred into separating funnels and extracted using 4.5 ml CH2Cl2 and were shaken for (4 minutes). The extracted organic layer was used for the preparation of the calibration curves for spectrophotometric measurements of VH at 437nm. The blanks were carried out in exactly the same way throughout the whol
... Show MoreThe great raise and development of residential buildings in modern cities worldwide as a result of urban extends leads to environmental and social problems, that make the designers looking for more complicated and innovative solutions. To encounter these, most advanced technologies in construction had been used resulting buildings had become higher, which was moved away from the land called residential housing. And with the development of these buildings, increase in the inhabitants inside; generate distant from nature, which increased the need for interactive outdoor recreational spaces open green in its high sections, was an alternative or complementary option to outer space at the ground level. Therefore, the research problem has emer
... Show MoreThe problem of medical waste over the past tow decades has emerged as one of the most important issues.
Which have negative effects on health and the environment ,and as a result specialists looked into the field.
Public health and research issues . This phenomenon in all its dimensions and efforts made For their containment through the development of health and environmental controls for the disposal of such wastes.
In a safe manner starting form the source of these wastes and the various health organizations are finished The final treatment ,and this is why the producers of hazardous medical waste. &nb
... Show MoreThe Era of Henry VII is the king who established the Tudor as they ruled England for
(24) years .He made drasfic changes in British Economy and the state of the country was
stable and secure.
Thes economic achievement of make him Qualified to be called The founder of the
modern English History .
On the basis of that significance to study one of the development stages of one of the
developed societies presently, i.e. the English society, this thesis came under the title (The
Internal Policy in England 1509-1547) to examine the overall political, economic and social
positions England passed through. The thesis also indicated the intensive labor state suffered
by the English society with all its sections, especial
In this study, we conducted a series of polymerization studies of hexyl methacrylate in dimethyl sulfoxide with (0.1 - 0.4) mol dm-3 of monomer and (1 10-3 – 4 10-3) mol dm-3 of benzoyl peroxide as initiators at 70 °C. Using the well-known conversion vs. time technique, the effects of initiator and monomer concentration on the rate of polymerization (Rp) were studied. An initiator of order 0.35 was obtained in accordance with theory and a divergence from normal kinetics was detected with an order of 1.53 with respect to monomer concentration. The activation energy was determined to be (72.90) kJ mol-1, which does not correspond to the value of most thermally initiated m
... Show MoreBackground: Tumor associated tissue eosinophilia (TATE) has been described in a variety of neoplasms. In regard to squamous cell carcinoma, some studies worldwide done to assess stromal eosinophilia in oral and cervical squamous cell carcinoma. The objectives of this study is to evaluate the association of stromal eosinophilic infiltration of cutaneous squamous cell carcinoma and to detect the significance of this association.
Aim of the study
The aim of our study is to establish the relationship between the degree of stromal eosinophilia and the level of invasion and the histological grade in cutaneous squamous cell carcinoma.
Methods: In this retrospective study
... Show MoreAbstract
We produced a study in Estimation for Reliability of the Exponential distribution based on the Bayesian approach. These estimates are derived using Bayesian approaches. In the Bayesian approach, the parameter of the Exponential distribution is assumed to be random variable .we derived bayes estimators of reliability under four types when the prior distribution for the scale parameter of the Exponential distribution is: Inverse Chi-squar
... Show MoreThe design of the Graphic has recently taken a great variety in the curricula and design methods that have led to its applications for career advancement and aesthetic quality. This is due to the communicative role that it plays in the movement of human beings and their aspirations. Among these applications are the designs of magazine covers in different variations. The design of the cover is based on a structural system that requires awareness and skill from the designer, especially since the organizational structure in the design of the envelope is limited in both vocabulary and space, and in the neighborhood Many have the image of sovereignty and sometimes the other head line, and can lead color values are other.
In all
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