In this study, the effect of intersecting ribs with inclined ribs on the heat transfer and flow characteristics of a high aspect ratio duct has been numerically investigated. The Relative roughness pitch (P/e) is 10 and the Reynolds number range from 35,700 to 72,800. ANSYS (Fluent-Workbench 18.0) software has been utilized to solve the Reynolds averaged Navier-Stokes (RANS) equations with the Standard k-ε turbulence model. Three ribbed models have been used in this study. Model 1 which is a just inclined ribs, Model 2 which has a single longitudinal rib at the center with inclined ribs and Model 3 which has two longitudinal ribs at the sides. The results showed that the heat transfer rate has been enhanced when the intersecting ribs are used. Model 3 has achieved the highest overall thermal performance. The increasing in Nusselt number ratio (Nu /Nus ) for Model 3 and 2, relative to Model 1, are 13.19% and 7.03%, respectively. Consequently, the hybridizing by intersecting ribs with inclined ribs is considered as an advantageous technique to enhance the heat transfer.
سمير خلف فياض * و محسن طالب د.نوال عزت عبد اللطيف*, مجلة الهندسة والتكنولوجيا, 2010
This research aimed to examine the effect of concentration of dyes stuff, contact time, temperature and ratio of adsorbent weight in (gm) to volume of solution in (ml) on the percentage removal. Two dyes were used; direct blue 6 and direct yellow and the adsorbent was the maize cob. Batch experiments were performed by contacting different weights of adsorbent with 50 ml of solution of desired concentration with continuous stirring at various temperatures. The percentage of removal was calculated and the maximum percentage of removal was 80%. And as the concentration of solution, contact time, temperature and the ratio of adsorbent to volume of solution increase the percentage of removal increase.
The purpose of this study was to examine the association of oral administration of Carbamazepine during pregnancy and the histological changes in the ovaries of mice. Timed-pregnant mice were divided into experimental and control groups. 60 mice in the experimental group received daily oral of 15 mg/kg of carbamazepine via intragastric tube on gestational days 0 to 18. 20 mice were used as control group. They received normal saline via the same route. Dams underwent laparotomy on pregnancy days 13, 15, and 18 and the ovaries were collected. Routine histological processing of the ovaries histology of paraffin sections stained with haemotoxylin and eosin, were conducted. The ovary under the effect of the drug, there was signs of degeneration
... Show MoreThe work demonstrates the effect of cold atmospheric plasma (CAP) on adult female rats suffering from osteoporosis, the used plasma was generated by a floating electrode-dielectric barrier discharge system with an electrode diameter of 3 cm. The output power was from (12-20) watts. The effect of non-thermal plasma was observed on rats with various exposure times of 20, 30, and 40 sec. It was noted that the blood calcium percentage of animals exposed to cold plasma increased, as well as an increase in the level of vitamin D3 at the same time, it is noted that there is no effect on parathyroid hormone level. For the thyroid gland, it is noticed an increase in the level of T3, and T4 hormones in the blood during the period of induction for
... Show MoreThe presence of residual antibiotics in water results in the development of antibiotics resistant genes. The available wastewater treatment systems are not capable of removing such antibiotics from sewage. Thus, antibiotics need to be removed before the discharge of wastewater. Adsorption is among the promising techniques for the wastewater treatment to aid the removal of a wide range of organic and inorganic pollutants. The present work is a contribution to the search for an economical method for the removal of low concentrations of amoxicillin (AMX) from water by adsorption on water treatment residue, WTR, taken from a local drinking water facility. The chemical composition and the adsorptive characteristics of the material were first
... Show MoreThe purpose of this study is to evaluate the hydraulic performance and efficiency of using direction diverting blocks, DDBs, fixed on the surface on an Ogee spillway in reducing the acceleration and dissipating the energy of the incoming supercritical flow. Fifteen types of DDB models were made from wood with a triangulate shape and different sizes were used. Investigation tests on pressure distribution at the DDBs boundaries were curried out to insure there is no negative pressures is developed that cause cavitation. In these tests, thirty six test runs were accomplished by using six types of blocks with the same size but differ in apex angle. Results of these test showed no negative pressures developed at the boundarie
... Show MoreIn recent decades, the identification of faces with and without masks from visual data, such as video and still images, has become a captivating research subject. This is primarily due to the global spread of the Corona pandemic, which has altered the appearance of the world and necessitated the use of masks as a vital measure for epidemic prevention. Intellectual development based on artificial intelligence and computers plays a decisive role in the issue of epidemic safety, as the topic of facial recognition and identifying individuals who wear masks or not was most prominent in the introduction and in-depth education. This research proposes the creation of an advanced system capable of accurately identifying faces, both with and
... Show MoreTransportation and distribution are the most important elements in the work system for any company, which are of great importance in the success of the chain work. Al-Rabee factory is one of the largest ice cream factories in Iraq and it is considered one of the most productive and diversified factories with products where its products cover most areas of the capital Baghdad, however, it lacks a distribution system based on scientific and mathematical methods to work in the transportation and distribution processes, moreover, these processes need a set of important data that cannot in any way be separated from the reality of fuzziness industrial environment in Iraq, which led to use the fuzzy sets theory to reduce the levels of uncertainty.
... Show More