Adsorption and ion exchange are examples of fixed-bed sorption processes that show transient behavior. This means that differential equations are needed to design them. As a result, numerical methods are commonly utilized to solve these equations. The solution frequently used in analytical methods is called the Thomas solution. Thomas gave a complete solution that adds a nonlinear equilibrium relationship that depends on second-order reaction kinetics. A computational approach was devised to solve the Thomas model. The Thomas model's validity was established by conducting three distinct sets of experiments. The first entails the adsorption of acetic acid from the air through the utilization of activated carbon. Following this, zeolite-5A adsorbs trichloroethylene (TCE) from the air. Finally, activated carbon is employed for the purpose of adsorbing o-cresol from aqueous solutions. A study was done to estimate phase equilibria and interphase mass transfer rates. To find the kinetic mass-transfer coefficient (K) for gases, the phase coefficients for mass transfer in the fluid phase ( ) and the pore phase ( ) were added together. The estimation of (K) for liquid was performed using the mass transfer coefficient for the solid phase and togather. The results suggest that the adsorption of acetic acid from air on activated carbon gives a good agreement with the Thomas model. The other sets of data demonstrate a disparity due to the underlying assumptions inherent in the Thomas model.
Objective: The purpose of this study was to determine the association between caries related microorganisms in children’s saliva, such as Streptococcus mutans and lactobacilli, and their demographic factors. Methods: This study involved a sample of 135, both sexes with an age range between 3 and 10 years. Unstimulated saliva was obtained and diluted in normal saline. Saliva was then placed in selective media. Salivaris agar was used for mutans streptococci while Rogosa agar for lactobacilli. After incubation, Streptococcus mutans counting of CFU (colony forming units) with morphology characterization and numbers of CFU per milliliter of saliva for lactobacilli. Demographic factors information was collected using a questionnaire.
... Show MoreArray antennas have an interesting role in the radio astronomy field. The array antennas allow astronomers to obtain high-resolution signals with high sensitivity to weak signals. This paper estimates the meteors' positions entering the Earth's atmosphere and develops a simulation for array antenna radar to analyze the meteor's echoes. The GNU radio software was used to process the echoes, which is a free open-source software development toolkit that provides signal processing blocks to implement in radio projects. Then, the simulation determines the azimuth and elevation of the meteors. An improved Multiple Signal Classification (MUSIC) algorithm has been suggested to analyze these echoes. The detected power of each meteor echo has
... Show MoreThe genic variation analysis of Pseudomonas aeruginosa after filtering the spurious variation appeared that 222 variable loci out of 5572 loci were detected. The type of variation analysis revealed that single nucleotide polymorphism was highly significant compared with other types of variation due the fact that the genome variation was achieved on the level of microevolution. Moreover, the proportional effect of functional scheme showed that genes responsible for environmental information were the highest comparable to another scheme. The genes of environmental information processing locate on outer membrane and face the defense strategy of the host therefore change in proteins coded by these genes lead to escape the immune system defense
... Show MoreGypsum is one of the important construction materials in Iraq in plastering surfaces and gypsum board , the ability of gypsum to give a comfortable an aesthetic ambiance as a construction material increase the need of gypsum , The particle size , total surface area and particle size distribution were factors affecting plaster properties used for construction properties . In this study gypsum paste was used with different mixing ratios of particle size and studied the physical properties of these types of pastes named (standard consistency ,setting time ,density) and compressive strength . The results showed that the water to gypsum ratio increased with increasing the fineness of the gypsum to (0.75%) and the setting time to the maxi
... Show MoreIn this study 737 stool specimens were collected from people attending some primary health care centres and hospitals in North of Baghdad, during the period from beginning of April 2009 till the end of March 2010. Different factors were examined to be related with the prevalence of Cryptosporidiosis which were (number of family member, travelling history, source of drinking water and domestic animal present). Significant relations (p≤0.05) were observed between infection rate and the following factor: -Number of family member: The high percentage of Cryptosporidium spp positive cases were seen in families composed of (15-19) and (more than 20) individual which were 28.32% and 16.37% respectively when compared with other family clusters -T
... Show MoreThe bacterial isolates were obtained from Al-Kindi Hospital were diagnosed by the Vitek-2 system and re confirm by 16srRNA gene as S. aurous, the results were shown 20 isolates (66.7%) out of 30 isolates were positive to protease production. All bacterial isolates (100%) were sensitive to Gentamicin and Levofloxacin. but resistant (100%) to aztreonam. The best temperature for enzyme production from bacteria was 37 °C, and the best pH for enzyme production was 7. Partial purification of the bacterial enzyme (protease) was carried out using short steps included ammonium sulfate 65% saturation, ion exchange using DEAE- cellulose column and then applied on gel filtration chromatography using Sephadex G-200 column. The enzymatic activit
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