This article deals with estimations of system Reliability for one component, two and s-out-of-k stress-strength system models with non-identical component strengths which are subjected to a common stress, using Exponentiated Exponential distribution with common scale parameter. Based on simulation, comparison studies are made between the ML, PC and LS estimators of these system reliabilities when scale parameter is known.
This study aims to assess the concentrations of some Poly Aromatic
Hydrocarbons in water, in order to monitor effectively and provide possible
recommendations to improve the water quality in the aquatic ecosystem of Tigris
River near Al-Dora refinery. Distribution and concentration of the sixteen polycyclic
aromatic hydrocarbons (PAHs) were studied in surface water. Solid-phase extraction
was used for water samples, and then analyzed by HPLC. Results showed that the
highest and the most dominant (PAH) was ancephthlnene (3-ring PAH), with
concentration of (40.33 ng/l), while the lowest concentration was for Indeno (1, 2, 3-
cd) pyrene (5-ring PAH), with (0.33 ng/l). The highest and the lowest mean
concentrations
The aim of this study was to investigate the effect of operating variables on, the percentage of removed sludge (PSR) obtained during re-refining of 15W-40 Al-Durra spent lubricant by solvent extraction-flocculation treatment method. Binary solvents were used such as, Heavy Naphtha (H.N.): MEK (N:MEK), H.N. : n-Butanol (N:n-But), and H.N. : Iso-Butanol (N:Iso:But). The studied variables were mixing speed (300-900, rpm), mixing time (15-60, min), and operating temperature (2540, oC). This study showed that the studied operating variables have effects where, increasing the mixing time up to 45 min for H.N.: MEK, H.N.: n-Butanol and 30 min for H.N.: Iso-Butanol increased the PSR, after that percentage was decreased; increasing t
... Show MoreThe first studies on shocks and vibrations were carried out at the beginning of the 1930s to improve the behavior of buildings during earthquakes. Vibration tests on aircraft were developed from 1940 to verify the resistance of parts and equipments prior to their first use. Flutter is a well-known example of dynamic aero elasticity, where when oscillation of structure interacted with unsteady aerodynamic forces the flutter will occur. Vibration on any structure without damping means that self-harmonic oscillation will occur, and in most cases the oscillation may start to increase until structural failure. This behavior is very similar to resonance phenomena if only the oscillation is being studied as a vibration case. In vibration suppre
... Show MoreSix isolates of Bacillus thuringiensis were isolated from Iraqi soil characterized as non- insecticidal and non- hemolytic parasporal inclusion proteins. Bacterial isolates were propagated on nutrient broth. Then, the parasporal inclusion proteins were extracted and processed with proteinase K and trypsin. The major protein segments produced of 64KDa were characterized and tested for cytocidal activity against human leukemic T- cells (CLL) (Chronic lymphoid leukemia). Results indicated that the treated parasporal proteins of four isolates (Bt2, Bt3, Bt4 and Bt6) showed strong cytotoxicity with no significant differences between normal lymphocytes and leukemic lymphocytes. Two isolates BtA1 and BtA5 show discriminative cytotoxicity between n
... Show MoreBackground: Hyperthyroidism is a serious public concern, due the continuous increase in its prevalence and its impact on the mortality rates. Autoimmune hyperthyroidism is seen as a thyroid gland problem. Pro-inflammatory cytokines are crucial for the growth and development of hyperthyroidism, it was shown that the level of several pro-inflammatory cytokines were higher in the hyperthyroidism patients. Objective: This work was aimed to assessment the concentration of certain cytokine in hyperthyroid patients. Materials and Methods: Sixty hyperthyroidism patients and 30 healthy individuals with age range from (30-65) years old were enrolled in this study through their presence at the National Center for Diabetes Treatment and Research in Bag
... Show MoreOne of the most important challenges facing the development of laser weapons is represented by the attenuation of the laser beam as it passed through the layers of atmosphere.This paper presents a theoretical study to simulate the effect of turbulence attenuation and calculates the decrease of laser power in Iraq. The refractive index structure C_n^2 is very important parameter to measure the strength of the atmospheric turbulence, which is affected by microclimate conditions, propagation path, season and time in the day. The results of measurements and predictions are based on the Kolmogorov turbulence theory. It was demonstrated by simulations that the laser weapons in Iraq were severely affected due to the large change in temperatures,
... Show MoreThe quality of groundwater should be improved by keeping safe water sources from contaminants in protective way by doing regular measuring and checkup before it supplied for usage. Private Wells do not receive the same services that wells supplying the public do. Well owners are responsible for protecting their drinking water. This work was carried out in Badra city, Iraq from December 2017 to May 2018, six wells water were investigated to determine the general characteristics of wells as well as studying the effect of environmental factors on the quality of water. The average of six wells were eleven parameters that is out of permissible limits were EC, Sal., Alk., TH, TDS, Na, Ca, Cl, SO4, Fe, Zn (4402-5183 /cm, 2.76-3.9 ppt
... Show MoreWatermelon is known to be infested by multiple insect pests both simultaneously and in sequence. Interactions by pests have been shown to have positive or negative, additive or non additive, compensatory or over compensatory effects on yields. Hardly has this sort of relationship been defined for watermelon vis-à-vis insect herbivores. A 2-year, 2-season (4 trials) field experiments were laid in the Research Farm of Federal University Wukari, to investigate the interactive effects of key insect pests of watermelon on fruit yield of Watermelon in 2016 and 2017 using natural infestations. The relationship between the dominant insect pests and fruit yield were determined by correlation (r) and linear regression (simple and multiple) analys
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