In this research, an organobentonite (HDTMA-BT) was prepared by modifying a jordanian bentonite (BT) with hexadecyltrimethylammonium bromide. By means of in situ free radical polymerization in THF with AIBN as the initiator, this organobentonite is used to prepare the polymethylmethacrylate-bentonite (PMA-HDTMA-BT) nanocomposite. Scanning electron microscopy (SEM), x-ray diffraction (XRD), energy dispersive spectrometer (EDS) and Fourier transform infrared (FTIR) spectroscopy were used to characterize both HDTMA-BT and PMA-HDTMA-BT. Those adsorbents were used in a batch process to remove Pb(II), Cr(III) ions, and p-chlorophenol (PCP) from aqueous solution. Investigated factors included adsorbent dosage, initial pH solution, contact time, and temperature. Adsorption data more fitted the Langmuir and D-R isotherms than the Freundlich isotherm. The maximum adsorption capacities, qmax, obtained from the Langmuir adsorption isotherm were 172.414 mg/g, 303.030 mg/g, 10.020 mg/g, 25.641 mg/g, 76.336 mg/g, and 163.934 mg/g for Pb/HDTMA-BT, Pb/PMA-HDTMA-BT, Cr/HDTMA-BT, Cr/PMA-HDTMA-BT, PCP/HDTMA-BT, and PCP/PMA-HDTMA-BT, respectively. The results on adsorption were found to be well-fit by the pseudo-second order kinetics model. The uptake of Pb(II), Cr(III) ions, or PCP onto HDTMA-BT and PMA-HDTMA-BT nanocomposite was primarily regulated by intraparticle diffusion, but boundary layer diffusion also took place in the adsorbate-adsorbent system. pH and temperature significantly influenced the adsorption process and negative values of suggest that the adsorption process was spontaneous and feasible.
Background: Dental erosion is a common oral condition which results due to consumption of high caloric and low pH acidic food such as carbonated drinks and fruit juices. It is expected that these food types can cause irreversible damage to dental hard tissues and early deterioration of the dental restorations. So, this study aimed to evaluate and compare the erosive potential effects of orange fruit juice and Miranda orange drink on the microhardness of an orthodontic composite material. Materials and methods: Thirty discs with a thickness of 2 mm and a diameter of 10 mm were prepared from orthodontic bonding composite. The prepared discs were equally divided into three groups (n=10). Microhardness analysis was carried out both prior to
... Show MoreThe current study was designed to investigate the effect of Tilletia smut spores on histopathological changes in liver and kidney in mice. Twenty animals were divided into two equal groups, 10 mice each, control group fed on normal diet and the treated groups were fed on a mixture of 50% normal diet with 50% wheat infected with Tilletia for 30 days. Histopathological sections taken from liver and kidney treated with Tilletia revealed several alterations. The changes in liver included, multiple granulomatous lesions, area of coagulation necrosis, vacuolar degeneration in the cytoplasm of hepatocytes, proliferation of hepatocytes with formation of pseudolobull which initiates for procancer. Whereas in the kidney, the changes included
... Show MorePositron annihilation lifetime (PAL) technique has been employed to
study the microstructural changes of polyurethane (PU), EUXIT 101
and epoxy risen (EP), EUXIT 60 by Gamma-ray irradiation with the
dose range (95.76 - 957.6) kGy. The size of the free volume hole and
their fraction in PU and EP were determined from ortho-positronium
lifetime component and its intensity in the measured lifetime spectra.
The results show that the irradiation causes significant changes in the
free volume hole size (Vh) and the fractional free volume (Fh), and
thereby the microstructure of PU and EP. The results indicate that
the γ-dose increases the crystallinity in the amorphous regions of PU
and increas
Art education is one among the fundamental subjects for elementary school students, because it contributes to assembling learners’ personalities and developing their technical skills. For this reason, this research comes, which aims to understand the effect of the task groups’ strategy in developing the performance of elementary school students in art education. to realize the goal of the research, the researcher put the subsequent hypotheses:
-There is not any statistically significant difference at the amount (5%) between the typical many students between the experimental group that studied consistent with the strategy of task groups and therefore the control group that studied in keeping with the same old method that they obt
E-commerce is the most important result of information technology in this day and age, has resulted in the use of commercial transactions to changes in economic, social, and psychological, and produced a new type of shopping, jobs, and create new job opportunities, and changed the traditional work environment. The challenge currently facing economic units is how to transfer this technology and its integration within the community, especially after the massive developments that have occurred in the areas of commercial and congested markets units, the economic and the products and services the many and varied and intensified competition among these units to achieve a profit, leading to the emergence of e-commerce as on
... Show MoreThe issue of peaceful coexistence between societies is the topic of the hour, as it is one of the important issues in this era, especially in days when conflicts and conflicts abound, and even wars in the name of religion, gender, race, language, and the like. The world, so that single-mindedness and adherence to one opinion and intolerance to it became the method of dialogue in our world today, as writing in the field of peaceful coexistence, peace-building, tolerance, pluralism, and acceptance of the other is one of the new fields of knowledge in Iraq in general and in Nineveh Governorate in particular, as peaceful coexistence is one of the basic needs And necessary for the presence of individuals in societies, and it requires the achi
... Show MoreThe Isolated Combustion and Diluted Expansion (ICADE) internal combustion engine cycle combines the advantages of constant volume combustion of the Otto cycle with the high compression ratio of the Diesel cycle. This work studies the effect of isolated air mass (charge stratification) on the efficiency of the cycle; the analysis shows that the decrease of isolated air mass will increase the efficiency of the cycle and the large dilution air mass will quench all NOx forming reactions and reduce unburned hydrocarbons. Furthermore, the effect of Fuel / Air ratio on the efficiency shows that the increase of Fuel / Air ratio will increase efficiency of the cycle.
This paper represents an experimentalattempt to predict the influence of CO2-MAG welding variables on the shape factors of the weld joint geometry. Theinput variables were welding arc voltage, wire feeding speed and gas flow rate to investigate their effects on the shape factorsof the weld joint geometry in terms of weld joint dimensions (bead width, reinforcement height, and penetration). Design of experiment with response surface methodology technique was employed to buildmathematical models for shape factors in terms of the input welding variables. Thepredicted models were found quadratic type and statistically checked by ANOVA analysis for adequacy purpose. Also, numerical and graphical optimizations were carried out
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