Box-Wilson experimental design method was employed to optimized lead ions removal efficiency by bulk liquid membrane (BLM) method. The optimization procedure was primarily based on four impartial relevant parameters: pH of feed phase (4-6), pH of stripping phase (9-11), carrier concentration TBP (5-10) %, and initial metal concentration (60-120 ppm). maximum recovery efficiency of lead ions is 83.852% was virtually done following thirty one-of-a-kind experimental runs, as exact through 24-Central Composite Design (CCD). The best values for the aforementioned four parameters, corresponding to the most restoration efficiency were: 5, 10, 7.5% (v/v), and 90 mg/l, respectively. The obtained experimental data had been utilized to strengthen a semi-empirical model, based on a second-degree polynomial, to predict recovery efficiency. The model was tested using ANOVA software (Design expert®) and found acceptable R-Squared were (0.9673). Yield responseurface and contour plots have been created using the developed model, which revealed the presence of high-recovery plateaus whose specs will be useful in controlling pilot or industrial scale future devices to ensure economic feasibility.
A numerical computation for determination transmission coefficient and resonant tunneling energies of multibarriers heterostructure has been investigated. Also, we have considered GaN/Al0.3Ga0.7N superlattice system to estimate the probability of resonance at specific energy values, which are less than the potential barrier height. The transmission coefficient is determined by using the transfer matrix method and accordingly the resonant energies are obtained from the T(E) relation. The effects of both well width and number of barriers (N) are observed and discussed. The numbers of resonant tunneling peaks are generally increasing and they become sharper with the increasing of N. The resonant tunneling levels are shifted inside the well by
... Show MoreThe current research seeks to know the difficulties in memorizing literary texts with fourth grade students from teachers’ point of view of and students
The research contains a community of (10,870) students from schools affiliated to the Directorate of Karkh, second and the number of schools for boys and girls (79) School and the number of teachers (349) who are specialized in teaching Arabic language to fourth grade preparatory students and there was a section of a randomly sample of each of the students, teachers and schools .
Some actions which can be listed below:-The survey which was done by the researcher for the views of the two samples from teachers and students as the number of teachers covered in this research (20) and
Background: The human face has its special characteristics. It may be categorized into essentially three kinds in horizontal and vertical directions: short or brachyfacial, medium or mesofacial and long or dolichofacial. The aim of this study was to describe several orofacial indices and proportions of adults, according to gender in Iraqi subjects by using cone beam computed tomography . materials and methods: This prospective study included 100 Iraqi patients (males and females) ranging from 20 to 40 years. All subjects attended the Oral and Maxillofacial Radiology Department of Health Specialist Center for Dentistry in AL Sadr city in Baghdad taking cone beam computed tomography scan for different diagnostic purposes from October 2016 to
... Show MoreFinancial Reporting Quality (FRQ) is one of the important topics in the financial management, it has the impact on the users decisions, it also effect on many other variables i.e dividend, therefore. This paper aims to provide a diameter of Financial Reporting Quality (FRQ) level for the companies listed on the Iraqi Stock Exchange. It also tries to show the FRQ effects on the dividend policy. The study sample was 13 listed companies in the Iraqi Stock Exchange for the period from 2007 to 2011. Kothari et al. 2005 model has been used to measure the FRQ, on the other hand the common stock share of the dividend was used to measure the dividend.
Many conclusions have been driven by the research
... Show MoreThe long – term behaviour of polyethylene products used out doors is affected by weathering. In the present work,
weathering test was carried out to find the effect of the environment conditions on the mechanical properties of
HDPE/LLDPE blends with different weight percents (0, 15, 30, and 45 %) relative to the LLDPE by increasing the
exposure times to (100, 150, 200, 250, 300) hr.
A series of tests (destructive), tensile, impact and hardness were carried out on the prepared samples, the results
obtained declare the changes on the material behaviour from ductile to brittle and the polymer shows a decline in the
mechanical properties with increasing the exposure times.
In the present work empirical equations were r
Nine new compounds of 2-amino-5-chlorobenzothiazole derivatives were synthesized. These new compounds were formed through the reaction of 2-amino-5-chlorobenzothiazole 1 with ethyl chloroacetate and KOH, which gave an ester derivative 2, followed by refluxing compound 2 with hydrazine hydrate to afford hydrazide derivative 3. The reaction of compound 3 with CS2 and KOH gave 1,3,4-oxadiazole-2-thiol derivative 4, and then the reaction of compound 2 with thiosemicarbazide to produce compound 5 then treated it with 4%NaOH led to ring closure to provide 1,2,4-triazole-3-thiol derivative
... Show MoreIn this research the activity of radon gas in air in Baghad governorate,Iraq, using “alpha-emitters track registration (CR-39) track detector were measured. This measurement was done for selected areas from Baghdad Governorate, The results obtained shows that the highest average concentrations for Rn-222 is (179.077 Bq/m^3) which was recorded within Al-Shaaib city and less average concentrations was (15.79 Bq/m^3) in the nearby residential area of Baghdad International Airport and the overall average concentrations is (86.508 Bq/m^3) for these regions. Then the radon concentration was measured annual effective dose calculated from radon concentration and found in range from 0.4031 mSv/y to 4.5179 mSv /y with an average value of 2.1824 m
... Show MoreRecent technological developments in the mass media a major paradigm shift in important segments of society, particularly among young people in particular social networking sites including (Facebook) .
it was able to link the sprawling parts of the world and paved the way for all the communities of convergence and exchange views, ideas and desires as provided by their ability to communicate through the use of video clips,pictures,share files, chat, communicate and direct interaction between the audience for this the means. Wondered problem Find the role that can be played using the university youth to the social networking site (Facebook ) to modify their attitudes or their interest in Iraqi society issues, With focused research objec
The attention of civil society organizations, governments and international non-governmental organizations in recent years has focused on the acute practices adopted by companies with the aim of reducing the tax burden, and the results of these practices have a negative impact on the tax revenues that the state uses to finance public needsThe aim of the research is to measure the impact of the voluntary disclosure of companies on tax planning for the period from 2011 to 2015 and the research community is in the General Tax Authority. The research sample is 6 companies within the private sector in the financial, banking, insurance and industrial fields. The research was based on a special model to measure the optional disclosure,
... Show MoreTwo‐dimensional buoyancy‐induced flow and heat transfer inside a square enclosure partially occupied by copper metallic foam subjected to a symmetric side cooling and constant heat flux bottom heating was tested numerically. Finite Element Method was employed to solve the governing partial differential equations of the flow field and the Local Thermal Equilibrium model was used for the energy equation. The system boundaries were defined as lower heated wall by constant heat flux, cooled lateral walls, and insulated top wall. The three parameters elected to conduct the study are heater length (7 ≤