Due to the broad range uses of chromium for industrial purposes, besides its carcinogenic effect, an efficient, cost effective removal method should be obtained. In this study, cow bones as a cheap raw material were utilized to produce active carbon (CBAC) by physiochemical activation, which was characterized using: SEM to investigate surface morphology and BET to estimate the specific surface area. The best surface area of CBAC was 595.9 m2/gm which was prepared at 600 ᵒC activation temperature and impregnation ratio of 1:1.5. CBAC was used in aqueous chromium ions adsorption. The investigated factors and their ranges are: initial concentration (10-50 mg/L), adsorption time (30-300 min), temperature (20-50 ᵒC) and solution pH (2-11). Isotherm of adsorption and its kinetics were studied. The adsorption process was modeled statistically and was represented by an empirical model. Equilibrium data were fitted to the Langmuir and Freundlich isotherm models and the data best represented by Freundlich isotherm. Pseudo- first order and pseudo- second order kinetic equations were utilized to study adsorption kinetics, where chromium adsorption on CBAC fitted pseudo- second order fitted the data more adequately. The best removal efficiency was found to be 94.32%.
ABSTRACTBackground : Acne vulgaris is a
common skin disease, affecting more than 85% of
adolescents and often continuing into adulthood.
People between 11 and 30 years of age and up to
5% of older adults. For most patients acne remains
a nuisance with occasional flares of unsightly
comedones, pustules and nodules. For other less
fortunate persons, the sever inflammatory response
to Propionibacterium acnes (P.acnes) results in
permanent
Methods: Disfiguring scars. (1, 2) Stigmata of sever
acne cane lead to social ostracism, withdrawal
from society and severe psychologic
depression (1-4).
Result Pathogenesis of acne Traditionally, acne
has been thought of as a multifactorial disease of
the fo
Abstract
The study deal with two main variables:- the dimensions of distribution, and the customer loyalty . the researcher has chosen samples of Iraqi newspapers like (AL Sabah, AL Mada, AL Bayna aljdeida newspaper), because this product depends greatly on the consumption of customers so as to achieve the success. After studying the dimensions of these variables ( cost, flixibilty & deliver time ) which concerns the distribution, and for these dimensions ( marketing relationship, customer perception, customer experience, brand, & product quality) which relate to the customer loyalty . the problem has been identified in a number of remarks concerning the extent of awareness that the administration
... Show MoreThe current research deals with the specificity of the interior design of the classes of art education in the schools of excellence for the province of Muthanna and its center of the city of Samawah. In the first chapter، the problem of research was determined by the lack of internal spaces of the classes of art education to designs that meet the requirements and needs of students in these educational stages. The importance of the research in being an addition to knowledge in the field of interior design and engineering department of the general directorates of the Ministry of Education. The objectives of the research were determined through.
- Identifying the reality of the halls of art education for sch
The childhood stage is considered the most important stage of all the stages through
the human being’s life. In this stage the human being will be more affected by the various
factors that surround him/her. The first five years of his/her life leave a great impact not only
on the human being personality, but also on his/her whole life. Therefore, it is worthwhile tobe concerned with and focus at the raising up and the teaching of the child during the
childhood stage.
The mission of raising up children in this era - the era of globalization and information
bursting or news flooding – has become a very difficult or even an impossible mission.
Furthermore, not only in the Arabic world, but also all over the world, t
The relationship between the elements of the climate and the productivity of citrus (kg
/ tree) in the province of Karbala has been determined through the use of simple correlation
coefficient of Pearson (rp) and (t) test. The result for each of oranges, limes and tangerine had
all shown moral and relevant statistical indications; except for relative humidity, which were
not linked to a moral relationship with productivity of tangerine, oranges and limes.As for the
relationship between climatic factors and yield of bitter orange were all not significant
statistically and very weak.
In order to determine the strength of the correlation between fluctuations in the
climatic elements and fluctuations in the productivi
The current research aims to identify the level of extension of the sense of self and the cognitive style (complexity - simplification) among university students, as well as the significance of the difference according to gender (males - females), as well as the correlation between the two variables, and in order to verify this, the researcher has constructed The measure of the extension of the sense of self based on the theory of Alport 1961, as the number of its final paragraphs reached (28) paragraphs, and the cognitive style scale (complexity - simplification) prepared by (Abdullah 2017) was adopted, as the scale consisted of (32) paragraphs in its final form. To verify their psychometric properties, and the two tools were applied to
... Show MoreThe process of evaluating and measuring tax performance is critical to support the tax collection process. The comparison of the amount of revenue collection with what is expected and the process of measuring tax performance continuously by the tax administration leads to increase the collection of tax, determine the size of deviations and stand and know the reasons and take the necessary measures to address them to get a better result in the future. According to the different tasks assigned to them, criteria and indicators for measuring the tax performance vary from one organization to another. These are indicators or criteria that measure tax revenue (i.e., amounts). One of the research's main findings was to raise the tax collection leve
... Show MoreThe effect of D phase polyamide (PA6)on the rheological properties, Young Modulus and the thermal expansion coefficient of two blends groups (bitumen-polyamide) were tested. The first group was for bitumen-PA6 blends and the second group for bitumen blended with polymer resulted from the crystallization of PA6-formic acid solution in water(PAFW).The obtained results proved that adding both types of polyamide has led to a rise in toughness and softening point temperature while the penetration Index approached -3 after adding the polyamide. So, all these changes make bitumen-polyamide blends more suitable for use in hot climate regions. The blends properties were explained according to the reaction that takes place between the polyamide and
... Show More