The present work presents a new experimental study of the enhancement of turbulent
convection heat transfer inside tubes for combined thermal and hydrodynamic entry length of one
popular “turbulator” (twisted tape with width slightly less than internal tube diameter) inserted for
fire tube boilers. Cylindrical combustion chamber was used to burn (1.6 to 7kg/h) fuel oil #2 to
deliver hot gases with ranges of Reynolds number (10500 to 21700), and (11400 to 24150) for both
empty and inserted tube respectively.A uniform wall temperature technique was used by keeping
approximately constant water temperature difference (25ºC) between inlet and exit cooling water in
parallel flow shell and tube heat exchanger. The test

Background: The vasoconstricting agents: nor-adrenaline and 5- hydroxytryptamine
(5-HT) have a stimulant action on smooth muscle contractility of the rat vas deferens.
Objective: This study aimed to investigate the effect of exposure to continuous
darkness and continuous light on the contractility of the vasa deferntia smooth
muscles from rats to applied nor-adrenaline and 5-HT.
Method: Male albino wistar rats were divided into 3 experimental groups. Group 1:
Control animals, were exposed to the ordinary photoperiod each day. Group 2: Rats
were kept in a dark room. Group 3: In a room under a bright artificial light.
All animals were killed after 4 weeks.
Results: Vasa deferentia preparations from continuous dar

Objective: To identify the effect of the cube model on visual-spatial intelligence and learning the skill of spikinging in volleyball for female students, The researchers used the experimental method by designing two equivalent groups with pre- and post-measurements. Research methodology: The main research sample of (30) female students was selected from the research community represented by second-stage students in the College of Physical Education and Sports Sciences - University of Baghdad for the academic year (2024-2025). The sample was divided equally into two control and experimental groups. The researchers conducted the sample homogenization process and the equivalence process between the two groups in the variables of visua

Autorías: Muayad Kadhim Raheem, Lina Fouad Jawad. Localización: Opción: Revista de Ciencias Humanas y Sociales. Nº. 21, 2019. Artículo de Revista en Dialnet.

Abstract

The current research aims to identify the effect of the proposed strategy in accordance with realistic mathematics on the achievement and mathematical Interrelation of third Intermediate students. Two samples were tested from the middle third grade in a school affiliated with the General Directorate of Baghdad- Rusafa, the first for the academic year (2022-2021). The experimental group is (30) students taught according to the proposed strategy, and the control group is (30) students based on the traditional method. To achieve the research objective, the researchers developed a test for achievement consisting of (30) items and a test of sports interconnection composed of (20) items. The results of the stu

Faujasite type NaY zeolite catalyst was prepared from locally available kaolin, then the prepared NaY zeolite have been modified by exchanging of sodium ion with ammonium to produce NH4Y zeolite. NH4Y zeolite was converted to HY zeolite by ion exchanging with oxalic acid. Zinc and nickel promoters have been added to the prepared HY zeolite catalyst, and the effect of these promoters on the catalytic activity of the prepared HY catalyst was studied in fluid catalytic cracking process using light gas oil as a feedstock. The experimental results show that the promoted catalyst gives higher gas oil conversion and gasoline yield than HY zeolite catalyst at the same reaction temperature and WHSV. It was also found that the promoted catalyst gi

The aim of this research is to find out the influence of Daniel's model on the skills of the twenty-first century among the students of the scientific-fifth grade at the secondary and preparatory government morning schools for the academic year 2022- 2023. Two groups were chosen out of five groups for the fifth-scientific grade, one of which represents the experimental group that is taught by the Daniel model, and the other is the control group that is taught in the traditional method. The equivalence of the two research groups was verified with a set of variables. As for the research tool, a scale was developed by the researchers for the skills of the twenty-first century, in which they adopted the framework of the Partnership Organizat

Vibration is a source of energy that can be beneficial or harmful based on the application. Vibration can affect the function of any structure; however, Ceramic matrix composite (CMC) is one of these structures. Whereby less studies have been concentrated on study its function specially when electromagnetic wave (microwave) exposed on its surface to perform its designed function. To address this concept, SiC composite has been fabricated which is designed to have a transparent characteristics to microwave. External vibration had been applied on its surface to monitor how much influence could nanoscale amplitude vibration damage the microwave interaction. The source of vibration was applied from piezoelectric and the vibration was monitored