In the present study, multi-walled carbon nanotubes (MWCNTs) with outside diameters of< 8 nm and 20−30 nm were covalently functionalized with β-Alanine using a novel synthesis procedure. The functionalization process was proved successful using Raman spectroscopy, FTIR, and TEM. Utilizing the two-step method with ultrasonication, the MWCNTs treated with β-Alanine (Ala-MWCNTs) with weight concentrations of 0.025%, 0.05%, 0.075%, and 0.1% were dispersed in distilled water to prepare water-based nanofluids. The aqueous colloidal dispersions of pristine MWCNTs were unstable. While for Ala-MWCNTs and after> 50 days from preparation, higher colloidal stability was obtained up to relative concentration of 0.955 and 0.939 for the 0.075-wt% samples of Ala-MWCNTs < 8 nm and Ala-MWCNTs 20−30 nm, respectively. The measured values of thermal conductivity were in very good agreement with the model of Nan, Birringer, Clarke and Gleiter and increased as temperature, specific surface area (SSA), and weight concentration increased, up to 14.74% for Ala- MWCNTs < 8 nm and 12.29% for Ala-MWCNTs 20−30 nm. The viscosity increased as weight concentration increased, up 25.69% for 0.1-wt% Ala-MWCNTs 20−30 nm, and decreased with the increase in temperature. Since the matching between the measured values of viscosity and the classical models of Batchelor, Brinkman, and Einstein was bad, a correlation was developed and revealed good agreement. The density and specific heat decreased as temperature increased. As weight concentration increased, the density slightly increased up to 0.065% for Ala-MWCNT < 8 nm while the specific heat decreased down to 0.95% for Ala-MWCNTs 20−30 nm, in comparison with water. The equations of (Pak and Cho) and (Xuan and Roetzel) were in good agreement with the measured values of density and specific heat, respectively. The aqueous colloidal dispersions of Ala-MWCNTs that were prepared in this work displayed robust candidature as successful substitutes for the conventional heat transfer fluids in different engineering applications for enhanced thermal performance.
Objectives: This study aims to broaden our knowledge of the role of eDNA in bacterial biofilms and antibiotic-resistance gene transfer among isolates. Methods: Staphylococcus aureus, E. coli, and Pseudomonas aeruginosa were isolated from different non-repeated 170 specimens. The bacterial isolates were identified using morphological and molecular methods. Different concentrations of genomic DNA were tested for their potential role in biofilms formed by study isolates employing microtiter plate assay. Ciprofloxacin resistance was identified by detecting a mutation in gyrA and parC. Results: The biofilm intensity significantly decreased (P < 0.05) concerning S. aureus isolates and insignificantly (P > 0.05) concernin
... Show MoreAbsorption, fluorescence, quantum yield and lifetime of rhodamine 6G in chloroform, methanol and dimethyl sulfoxide were measured. From a comparison of these quantities, with those for solid solutions (solid solutions are obtained by mixing constant volume proportions of dye at a concentration of 1*10-4M/l with different volume proportions from the concentrated solution of polymer in chloroform and dimethyl sulfoxide). The results showed that the addition of polymer to liquid concentrated solutions (1*10-4M/l )of rhodamine 6G dye from expecting [which leading to development active medium for laser dye at high concentration] increase the spectra shift toward high energies, and the luminescence quantum yield but decreasing radiative lifetim
... Show MoreMT Suhail, SA Hussein, MN Abdulhussein, WQ Abdaullateef, M khairallah Aid…, Migration Letters, 2024
Although the term' tautology' predicts negative connotation, it is often employed by poets and lyric writers to communicate more implied meanings. Through the use of tautological expressions, they exchange ideas, give more possibilities to readers to detect the meaning behind the tautological words and thus suggest details not openly communicated in the poem. Ten American song lyrics and ten American poems have been selected to be the data for the study. Data analysis is conducted on the basis of three steps:(i) identifying the type of tautology used ,(ii) detecting the syntactic realization of the tautology and (iii) finding the functions of the use of tautology in these lyrics and poems. The study concludes that song lyrics and p
... Show MoreBackground: Surgery is one and may be the most effective method to treat obesity. In the last decade, Laparoscopic Sleeve Gastrectomy is perceived to be less invasive, technically simple, less morbid and more popular form of bariatric surgery.
Objectives: This study aims to assess the effect of Laparoscopic Sleeve Gastrectomy on Fasting Blood Glucose Levels and Blood Pressure.
Methods: A prospective controlled study in which 50 obese patients were involved, 36 of patients have hypertension and type 2 diabetes mellitus , 7 patients have type 2 diabetes mellitus only, and 7 patients don’t have hypertension or type 2 diabetes. All patients were submitted to Laparosco
... Show MoreThis research deals with the perceived and the imagined in the texts of Yusef Al-Sayegh, considering language as the most important source in literature and theatrical criticism, and given the importance of the subject, the researcher monitored many philosophical and psychological opinions and theories related to (the perceived and the imagined), and they were discussed and their compatibility with the Iraqi theatrical t As for the second chapter, where (the theoretical framework), it included two topics, and the first topic was about the concept of the perceived and the imagined, and the second topic was about Youssef Al-Sayegh and the structure of the theatrical text.
In the third chapter, where (research procedures), the research
The present study aimed to evaluate the levels of total immunoglobulin E and percentage count of eosinophil in some of allergic disease. Blood sample collected from 210 patients (110 female, 100 male) with allergic disease (allergic asthma, allergic rhinitis, and urticaria) their age between 10-70 years and 50 healthy control their age between 23-52 years. A highly significant (P<0.01) increase in the mean serum total IgE in patients with asthma (503.54 ± 63.49 IU/ml), Allergic rhinitis (442.77 ± 95.76 IU/ml) and urticaria (489.53 ± 69.68 IU/ml) as a compared with healthy controls (23.67 ± 5.81 IU/ml).There was a significant difference in percentage count of eosinophil in patients groups allergic asthma 4.37 ± 0.52% ,allergic rhinitis
... Show More<p>The objective of this paper is to study the dynamical behavior of an aquatic food web system. A mathematical model that includes nutrients, phytoplankton and zooplankton is proposed and analyzed. It is assumed that, the phytoplankton divided into two compartments namely toxic phytoplankton which produces a toxic substance as a defensive strategy against predation by zooplankton, and a nontoxic phytoplankton. All the feeding processes in this food web are formulating according to the Lotka-Volterra functional response. This model is represented mathematically by the set of nonlinear differential equations. The existence, uniqueness and boundedness of the solution of this model are investigated. The local and global stability
... Show MoreRecently, Qatar, a well-known oil production country, has been convinced as a successful case in attracting foreign direct investment (FDI) as a smaller economy. This paper aims to investigate how FDI inflows affect Qatar’s business cycles. Time series data was selected from 1990 to 2010 as available. The VAR Impulse Responses and the Granger Causality test were mainly employed by using Eviews. The derived result shows that the FDI inflows and the economic growth in Qatar interact with each other in a relatively long term.