A rapid, simple and sensitive spectrophotometric method for the determination of trace amounts of chromium (VI) was studied. The method is based on the reaction of chromium (VI) with promethazine forming a red colored species by chromium in hydrochloric acid medium and exhibits a maximum absorbance at 518 nm. A plot of absorbance with chromium (VI) gives a straight line indicating that Beer’s law has been obeyed over the range concentration of 0.05-4.0 µg/ml with a molar absorptivity of chromium(VI) 2.04  104 l.mol-1.cm-1 , Sandell’s sensitivity index of 0.0025 µg.cm-2 while the limit of detection (LOD) was found to be 0.0924 µg.ml-1 and a relative standard deviation of (0.63-1.24)%,depending on the concentration level. The method is developed for the determination of chromium (III) and has been successfully applied to the determination of chromium in various water samples, pharmaceutical preparations, synthetic alloys and standard rock sample of known composition (MRG-1).
Background: Mini implant stability is primarily related to local bone density; no studies have evaluated bone density related to mini implant placement for orthodontic anchorage between different age groups in the maxilla and the mandible. The present research aims to evaluate side, gender, age, and regional differences in bone density of the alveolar bone at various orthodontic implant sites. Materials and method: Fifty three individuals who were divided into two groups according to their age into: group I (ages 16-20 years) and group II (ages 21-29 years) had subjected to clinical examination, then 64-multislice computed tomography scan data were evaluated and bone density was measured in Hounsfield unit at 102 points (51 in the maxilla
... Show MoreThe question of estimation took a great interest in some engineering, statistical applications, various applied, human sciences, the methods provided by it helped to identify and accurately the many random processes.
In this paper, methods were used through which the reliability function, risk function, and estimation of the distribution parameters were used, and the methods are (Moment Method, Maximum Likelihood Method), where an experimental study was conducted using a simulation method for the purpose of comparing the methods to show which of these methods are competent in practical application This is based on the observations generated from the Rayleigh logarithmic distribution (RL) with sample sizes
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Each phenomenon contains several variables. Studying these variables, we find mathematical formula to get the joint distribution and the copula that are a useful and good tool to find the amount of correlation, where the survival function was used to measure the relationship of age with the level of cretonne in the remaining blood of the person. The Spss program was also used to extract the influencing variables from a group of variables using factor analysis and then using the Clayton copula function that is used to find the shared binary distributions using multivariate distributions, where the bivariate distribution was calculated, and then the survival function value was calculated for a sample size (50) drawn from Yarmouk Ho
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This paper investigated the treatment of textile wastewater polluted with aniline blue (AB) by electrocoagulation process using stainless steel mesh electrodes with a horizontal arrangement. The experimental design involved the application of the response surface methodology (RSM) to find the mathematical model, by adjusting the current density (4-20 mA/cm2), distance between electrodes (0.5-3 cm), salt concentration (50-600 mg/l), initial dye concentration (50-250 mg/l), pH value (2-12 ) and experimental time (5-20 min). The results showed that time is the most important parameter affecting the performance of the electrocoagulation system. Maximum removal efficiency (96 %) was obtained at a current density of 20 mA/cm2, distance be
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The purpose of this paper is to shed light on the concept of fuzzy logic ,its application in linguistics ,especially in language teaching and the fuzziness of some lexical items in English.
Fuzziness means that the semantic boundaries of some lexical items are indefinite and ideterminate.Fuzzy logic provides a very precise approach for dealing with this indeterminacy and uncertainty which grows (among other reasons) out of human behavior and the effect of society.
The concept of fuzzy logic has emerged in the development of the theory of fuzzy set by Lotfi Zadeh(a professor of computer science at the university of California) in 1965.It can be thought of as the application side of the fuzzy set theory. In linguistics, few scholars
By using the deacetylation method, chitin is converted into bioproduct chitosan. Deacetylation can be accomplished using chemical or biological mechanisms. Due to its biocompatibility, nontoxicity, biodegradability, natural origin, and resemblance to human macromolecules, it is useful in medicine. Chitosan may have antibacterial and antioxidant properties. Additionally, it could be used in biotechnology, agriculture, gene therapy, food technology, medication delivery, cancer therapy, and other fields. The objective of the current review was to list the most significant applications of Chitosan in the biomedical field.
Background: Diabetic cheiroarthropathy is a term derived from the Greek word “cheiros” meaning “of the hand”, It is characterized by stiff hands with distinctively thick, tight, and waxy skin, especially on the dorsal aspects of the hands. It is part of long term complication of diabetes and many suggest it is associated with microvascular complication. The aim of the study was to determine the prevalence of diabetic cheiroarthropathy in Iraqi patients with diabetes, and to study its association with diabetic retinopathy and glycemic control. Material and Methods: A cross-sectional study in which 110 diabetic patients and 110 non-diabetic healthy people who accepted to take part in the study were ran
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