In this work, solid random gain media were fabricated from laser dye solutions containing nanoparticles as scattering centers. Two different rhodamine dyes (123 and 6G) were used to host the highly-pure titanium dioxide nanoparticles to form the random gain media. The spectroscopic characteristics (mainly fluorescence) of these media were determined and studied. These random gain media showed laser emission in the visible region of electromagnetic spectrum. Fluorescence characteristics can be controlled to few nanometers by adjusting the characteristics of the host and nanoparticles as well as the preparation conditions of the samples. Emission of narrow linewidth (3nm) and high intensity in the visible region (533-537nm) was obtained.
In this study a new strain of mesophilic Bacillus subtilis AIK, recorded for the first time in Iraq, was used to remove nickel (Ni) from aqueous solutions. The factors that affect bioremediation include temperature, pH value and metal concentrations. The results showed that the highest removal efficiency (R%) was 54, 52 and 48% at 25⁰C and pH of 5, 7 and 9, and with 10 ppm Ni concentration respectively. Whereas the highest R% recorded was 47, 45 and 52% at 30⁰C and of pH 5, 7, and 9 with 1 ppm Ni concentration respectively. On the other hand, the highest R% at 40⁰C was 49, 46, 42 % at pH 5, 7 and 9, with 5, 10 and 10 ppm Ni concentrations respectively. The results also showed that the optimum pH value for Ni removal at bot
... Show MoreIn petroleum industry, there are two major operations that can potentially impact the environment: Drilling and production. Both activities generate a significant volume of wastes include drill cuttings contaminated with hydrocarbons, wide variety of chemical additives, produced water and air pollutants. The potential impact depends primarily on the material, its concentration after release, and the biotic community that is exposed.
In this study, many drilling locations and production facilities have been investigated and examined for their adverse effects on the environment. Contamination with hydrocarbons, heavy metals, salts, other associated wastes and air pollution were detected at many sits.
Understanding of drilling and pro
A total of nine swab samples were collected from inflamed teeth and gingiva of human’soral cavity from a dentist clinic in Baghdad. All specimens were cultured in Mitis Salivarius agar medium and the isolated bacterial pure colonies werethen identified by using VITEK2. Three samples were diagnosed and identified as Staphylococcus lentus. One of the three isolates which showed a distinctive heavy growth on the media was selected for further analysis in this study. Paper disk diffusion method was used to detect the antibacterial activityof three of mouthwash solutions (Zak, Colgate and Listerine). The results showed that “Colgate†was the most active solution with antibacterial activity compared with the other two soluti
... Show MoreAll-optical canonical logic units at 40 Gb/s using bidirectional four-wave mixing (FWM) in highly nonlinear fiber are proposed and experimentally demonstrated. Clear temporal waveforms and correct pattern streams are successfully observed in the experiment. This scheme can reduce the amount of nonlinear devices and enlarge the computing capacity compared with general ones. The numerical simulations are made to analyze the relationship between the FWM efficiency and the position of two interactional signals. © 2015 Chinese Laser Press
Coated sand (CS) filter media was investigated to remove phenol and 4-nitrophenol from aqueous solutions in batch experiments. Local sand was subjected to surface modification as impregnated with iron. The influence of process variables represented by solution pH value, contact time, initial concentration and adsorbent dosage on removal efficiency of phenol and 4-nitrophenol onto CS was studied. Batch studies were performed to evaluate the adsorption process, and it was found that the Langmuir isotherm effectively fits the experimental data for the adsorbates better than the Freundlich model with the CS highest adsorption capacity of 0.45 mg/g for 4-nitrophenol and 0.25 mg/g for phenol. The CS was found to adsorb 85% of 4-nitrophenol and
... Show MoreLow-level microbial activity due to the production of organic acids is a recognized problem during the initial phase of food waste composting. Increasing such activity levels by adjusting the pH values during the initial composting phase is the primary objective to be investigated. In this study, sodium acetate (NaoAc) was introduced as an amendment to an in-vessel composting system. NaoAc was added when the pH of the compost mixture reached a low level (pH < 5), the addition increased pH to 5.8. This had a positive effect on the degradation of organic materials i.e. the formation of methane gas compared to the results without NaoAc addition.
The results also proved that anaerobic-aerobic in-vessel composting could reduce the
... Show MoreThe fresh water green alga Chlorella vulgaris was selected to study its ability to degrade one of polycyclic aromatic hydrocarbon (PAHs)known is anthracene (ANT). ANT is widely used in artificial products such as wood preservatives; insecticides; dye and coating materials. This algae was cultivated in CH-10 medium under constant laboratory conditions and exposed to different concentrations (1, 3, and 5 mg/l) of anthracene for 3, 5, 7, 9 and 15 days, with the concentration of ANT measured by high performance liquid chromatographic analysis (HPLC). The results showed that C.vulgaris has high ability to reduce anthracene to 80% at 1mg/Lcon centration after 3 days and 100% after 5 days, while at 3 and 5 mg / L concent
... Show MoreThe importance of this research lies in assessing the current state of media in Iraq based on international indicators and standards set by the Research and Scientific Exchange Council and UNESCO. That is to measure the strength and durability of media after 9 April 2003. These indicators are divided into five objectives that measure and describe each of the five research objectives that we seek to test through the points system.
Based on the foregoing, researchers in Iraqi media find that these conditions may lead to further decline unless measures are taken to help avoid mistakes, provide the requirements for development and progress. In addition, care from the State is needed to support this process, which would
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