In the present work, a closed loop circulation system consist of three testing sections was designed and constructed. The testing sections made from (3m) of commercial carbon steel pipe of diameters(5.08, 2.54 and 1.91 cm) . Anionic surfactant (SDBS )with concentrations of (50, 100, 150, 200 and 250 ppm) was tested as a drag reducing agent. The additive(SDBS)studied using crude oil from south of Iraq. The flow rates of crude oil were used in 5.08 and 2.54 cm I.D. pipes are (1 - 12) m3/hr while (1-6) m3/hr were used in 1.91 cm J .D. pipe . Percentage drag reduction (%Dr) was found to increase by increasing solution velocity, pipe diameter and additives concentration (i.e. increasing Renolds number). Also it was found that there is no change in apparent physical properties (viscosity) of crude oil after the addition of SDBS. The higher value of drag reduction of 54% in 5.08 cm I.D. was observed using 250 ppm SDBS surfactant dissolved in the used crude oil at flow rate of 12 m3/hr. Friction factor was calculated from experimental data. The friction factors values for pure solvent lies near or at Blasius asymptote suggested for flow of Newtonian fluids. After the addition of small amount of SDBS, the friction factor values were positioned below Blasius asymptote toward Virk maximum drag reduction asymptote, which was never reached.
In this research, the covariance estimates were used to estimate the population mean in the stratified random sampling and combined regression estimates. were compared by employing the robust variance-covariance matrices estimates with combined regression estimates by employing the traditional variance-covariance matrices estimates when estimating the regression parameter, through the two efficiency criteria (RE) and mean squared error (MSE). We found that robust estimates significantly improved the quality of combined regression estimates by reducing the effect of outliers using robust covariance and covariance matrices estimates (MCD, MVE) when estimating the regression parameter. In addition, the results of the simulation study proved
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Light has already becomes a popular means of communication, and the high-bandwidth data into free space without the use of wires. A great idea took us to design a new system for transmitting sound through free space at (650, 532) nm wavelengths using reflective mirrors under different atmospheric conditions. The study showed us the effect of various weather factors (temperature, wind speed and humidity) on these wavelengths for different distances. As well as studying the attenuation caused by long-distance laser and beam divergence, A reflective dish was used to focus the spot of the laser beam on the photocell. Results were discussed under the effect of these factors and the attenuation resulting from the beam divergence. Thus, the sys
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Finding the shortest route in wireless mesh networks is an important aspect. Many techniques are used to solve this problem like dynamic programming, evolutionary algorithms, weighted-sum techniques, and others. In this paper, we use dynamic programming techniques to find the shortest path in wireless mesh networks due to their generality, reduction of complexity and facilitation of numerical computation, simplicity in incorporating constraints, and their onformity to the stochastic nature of some problems. The routing problem is a multi-objective optimization problem with some constraints such as path capacity and end-to-end delay. Single-constraint routing problems and solutions using Dijkstra, Bellman-Ford, and Floyd-Warshall algorith
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Breast cancer is the most diagnosed form of malignant tumour in Iraqi women. Tamoxifen and trastuzumab are highly effective adjuvant therapy for breast cancer.
This study's objectives were to define the patient's belief in tamoxifen or trastuzumab when used as adjuvant therapy and to determine the variation in belief between the two medications in a sample of Iraqi breast cancer patients.
The cross-section survey was conducted using the BMQ-Specific questionnaire. Ninety-seven participants (sixty-seven tamoxifen, thirty trastuzumab) participated in this study.
The mean of specific-necessity scale for tamoxifen was (3.7) and for trastuzumab (4). The findings showed a high necessity for both medicines, and there wer
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The use of different materials in the art of ceramics is considered a new form of contemporary philosophical trends. That was introduced to art as a result of societal changes and transformations and rapid technological development. And it plays a very essential part in the beauty of the artistic structure. The contrast of using different materials in ceramics is considered a part of the old historical achievements since the art of ceramics used to follow strict standards. Which does not apply to contemporary ceramic, Because recently, it has become free from any religious and social control and created a whole new intellectual context, heading to new horizons in which it works with the newly added materials as a strategy to ensure the a
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In this work, we carried out an experimental study of thedusty
plasma by taking the dust material Fe3O4 with radius of the any grain
0.1μm - 0.5μm. In experiment we use air in the vacuum chamber
system under different low pressure (0.1-1) Torr. The results
illustrated that the present of dust particles in the air plasma did not
effect on Paschen minimum which is 0.5 without dust and with Fe3O4
dusty grains.
The effect of Fe3O4 dust particles on plasma parameters can be
notice in direct current system in glow discharge region. The plasma
parameters which were studied in this work represent plasma
potential, floating potential,electron saturation current, temperatu
A total of 258 voluntary blood donors (males 101; females 157) in the age range of 18-52 yr among males and 18-55 yr among females were examined for Toxoplasma gondii antibodies (IgG), and (IgM) by immunological technique (Enzyme linked Immunosorbant Assay) during the period from March 2009 to April 2010. This study covered a wide range of factors including immunological, age ,sex , place of residence and symptoms that may have a possible relationship with toxoplasmosis. Results presented in this study showed clearly that 38 (14.7%) of individuals participated in this study having IgG Toxoplasma Ab, among those 10 samples (9.9%) were males and 28 samples (17.8%) were females. Moreover, we found the prevalence of IgM seropositivity in th
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