The lead has adverse effects in contamination the aquatic environment, for this reason, a laboratory simulation was conducted using kaolinite collected from the Ga’ara Formation at western Iraq to be considered as a natural sorbent material that can be addressed Pb2+ from the aqueous environments. The Energy-Dispersive X-ray Spectroscopy and atomic absorption spectroscopy clarifying very fine grains and pure phase with a very little quantity of quartz and has a number of active sites for adsorption. The sorption of kaolinite for the Pb2+ has been carefully tested by several designed laboratory experiments. Five lead solutions of different concentrations (25, 50, 75, 100 and 125 ppm) were tested under different values of pH (1.3-9). The best sorption has been recorded at pH 9, with an equilibrium reaction time 40 m and the solid-liquid ration 1.25 gm:50 ml. The sorption reaction is endothermic with two main mechanisms were identified, the rapid ion exchange which gets at the beginning of the reaction during the first 10 m, and ion exchange, which gets slow later due to form ionic complexes
Specific microorganisms can produce bacterial nanocellulose (BNC), with acetic acid bacteria (AAB) being the most active producer. The family Acetobacteraceae includes the obligate aerobic, motile acetic acid bacteria. The BNC has attracted a lot of interest across a wide range of industries, including pharmaceuticals, due to its flexible characteristics, properties, and advantages. The present study was conducted to purify and characterize BNC produced from AAB isolated from apple vinegar. Bacterial nanocellulose was synthesized using a natural date palm liquid medium at pH 6 at 30°C for 8–10 days. The bacterial cellulose produced was then purified using a technique involving 0.1 M sodium hydroxide. To ascertain the surface mor
... Show MoreAcinetobacter baumannii ability to form biofilm makes it to be opportunistic pathogen causing of nosocomial infections and to be good survivor in adverse environmental conditions including medical devices and hospital environments. Six isolates of A. baumannii were isolated from drinking water and tested to investigate biofilm formation capacity on three different type of abiotic surface, also several factors were examined such as hydrophobicity, PH and temperature. All A. baumannii isolates displayed a positive biofilm on congored aga test CRA (pigmented colonies with black color) and Christensen's test (adhesive layer of stained material to the inside surface of the tube).The obtained data of microbial adhesion to hydrocarbons assay (MATH
... Show MoreViscosity (η) of solutions of 1-butanol, sec-butanol, isobutanol and tert-butanol were investigated in aqueous solution structures of ranged composition from 0.55 to 1 mol.dm-3 at 298.15 K. The data of (η/η˳) were evaluated based on reduced Jone - Dole equation; η/η˳ =BC+1. In the term of B value, the consequences based on solute-solvent interaction in aqueous solutions of alcohols were deliberated. The outcomes of this paper discloses that alcohols act as structure producers in the water. Additionally, it has shown that solute-solvent with interacting activity of identical magnitude is in water-alcohol system
The present work investigated the effect of distance from target surface on the parameters of lead plasma excited by 1064nm Q-switched Nd:YAG laser. The excitation was conducted in air, at atmospheric pressure, with pulse length of 5 ns, and at different pulse laser energies. Electron temperature was calculated by Boltzmann plot method based on the PbI emission spectral lines (369.03 nm, 416.98 nm, 523.48, and 561.94 nm). The PbI lines were recorded at different distances from the target surface at laser pulse energies of 260 and 280 mJ. The emission intensity of plasma increased with increasing the lens-to-target distance. The results also detected an increase in electron temperature with increasing the di
... Show MoreAbstract
This study aims to identify the most prominent factors that lead to bullying of students with intellectual disabilities in primary and middle schools from the perspectives of special education teachers. A quantitative descriptive approach was utilized. A questionnaire was used as a tool for data collection. The sample consisted of (72) male and female teachers from the Asir region in the Kingdom of Saudi Arabia. The results revealed the most prominent factors that lead to bullying as follows: factors associated with the school and its policies, factors associated with peers, factors associated with students with intellectual disabilities, and factors associated with general education teachers. The findin
... Show MoreThe present research aims to measure concentration of lead Pb214 in soil using remote sensing and GIS, associated radiological hazards in Baghdad, Iraq. Concentration of specific radioactivity of radioactive elements was measured and analyzed naturally and artificially in 48 soil samples for separate sites from Baghdad, Iraq using crystalline spectroscopy to detect germanium. The average radioactivity concentrations of lead were found, as it was found to have varying values from one site to another, as most of them exceeded the international permissible limit, as the highest concentration was recorded at 180 Bq in the sample H28 in Waziriyah district. Battery Lab (1), and the lowest concentration valu
... Show MoreIn this work, the mass attenuation coefficient, effective atomic number and half value layer parameters were calculated for silicate (SiO2) mixed with various levels of lead oxide and iron oxide as reinforced materials. SiO2 was used with different concentrations of PbO and Fe2O3 (25, 50 and 75 weight %). The glass system was prepared by the melt-quenching method. The attenuation parameters were calculated at photon energies varying from 1keV to 100MeV using the XCOM program (version 3.1). In addition, the mass attenuation coefficient and half value layer parameters for selected glass samples were experimentally determined at photon energies 0.662 and 1.28 MeV emitted from radioactive sources 137Cs and 22Na respe
... Show MoreIn this paper, the bi-criteria machine scheduling problems (BMSP) are solved, where the discussed problem is represented by the sum of completion and the sum of late work times simultaneously. In order to solve the suggested BMSP, some metaheurisitc methods are suggested which produce good results. The suggested local search methods are simulated annulling and bees algorithm. The results of the new metaheurisitc methods are compared with the complete enumeration method, which is considered an exact method, then compared results of the heuristics with each other to obtain the most efficient method.