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 tube consisted of smooth carbon steel tube of
(2400mm) long and (52mm) internal diameter. This test tube instrumented to derive local heat
transfer coefficient and local flue gasses static pressure.The experimental results show that for the
same fuel consumption, twisted tape insert with (H/D = 11.15) enhanced the mean Nusselt number
in (75.2%), (68.8%), (49.8%), (40.3%), and (16.7%) for fuel consumption (7kg/h), (6.16kg/h),
(4.5kg/h), (3.24kg/h), and (1.6kg/h) respectively.A set of empirical correlations that permit the
evaluation of the mean Nusselt number (for developing and fully developed region), and average
Nusselt number (for developed region) for empty and inserted tube are generated for engineering
applications.
The research risk of flooding on six water basins located in the eastern part of the western plateau, reached total area of the basin (22,998.9 km 2), has reached all the Basin area (basin to time 7056.1 km2 basin by 3585 km 2, Bath Alheiazi 6404 km 2, Abu beasts 544.1 km2 basin Abu Shannan 144.6 km 2, Bath Valley Faraj 5265.1 km 2), where it was specifically spatial degree of this risk by studying some of the hydrological basin transactions directly related to operations spate runoff study area and the occurrence of flood risks on the surface of ponds.
Two samples of (Ag NPs-zeolite) nanocomposite thin films have been prepared by easy hydrothermal method for 4 hours and 8 hours inside the hydrothermal autoclave at temperatures of 100°C. The two samples were used in a photoelectrochemical cell as a photocatalyst inside a cell consisting of three electrodes: the working electrode photoanode (AgNPs-zeolite), platinum as a cathode electrode, and Ag/AgCl as a reference electrode, to study the performance of AgNPs-zeolite under dark current and 473 nm laser light for water splitting. The results show the high performance of an eight-hour sample with high crystallinity compared with a four-hour sample as a reliable photocatalyst to generate hydrogen for renewable energies.
This study includes analytical methods for the determination of the drug amoxicillin trihydrate (Amox.) in some pharmaceutical preparations using Cobalt ion (Co(II)) as complexing metal. The best conditions for complexation were: the reaction time was 20 minutes, pH=1.5 and the best temperature of reaction was 70 ËšC. Benzyl alcohol was the best solvent for extraction the complex.
Keywords: Amoxicillin, Cobalt(II), Complex, Molar ratio.
The cross section evaluation for (α,n) reaction was calculated according to the available International Atomic Energy Agency (IAEA) and other experimental published data . These cross section are the most recent data , while the well known international libraries like ENDF , JENDL , JEFF , etc. We considered an energy range from threshold to 25 M eV in interval (1 MeV). The average weighted cross sections for all available experimental and theoretical(JENDL) data and for all the considered isotopes was calculated . The cross section of the element is then calculated according to the cross sections of the isotopes of that element taking into account their abundance . A mathematical representative equation for each of the element
... Show MoreObjective(s): To assess nurses' practices for neurological unconscious patients in intensive care units.
Methodology: A descriptive study was conducted that included (50) nurse who are working in intensive care
units in hospitals and departments of the nervous system in (4) hospitals (neuroscience hospital, teaching
neurosurgical hospital, surgical specialist hospital, and sheck zaied hospital) in Baghdad city from March, 30th
,
2009 to July, 30th 2009 for the purpose of assessing their skills towards unconscious patients. A purposive "nonprobability
sample" was selected that consisted of (50) nurse who are working in intensive care units. A
questionnaire format and observational checklist were used which consist of
Due to the importance of egg parasitoids inthe natural and biological control of economically important insects, including egg parasitoid Pseudoligositaba bylonica Viggiani on dubas bug, the spread of the parasitoid and population distribution of parasitoid, In order to estimate the role of parasitoid as one of the biological factors in decreasing population density of dubas bug on date palm. Some aspects of the life of parasitoids were also studied, including the role of insect parasitoids in organizing the population of their families, geographical distribution and hosts range of genus Pseudoligosita, seasonal presence of parasitoid Pseudoligositaba bylonica Viggiani (Hymenoptera: Trichogrammatidae) , life studies and percentages
... Show MoreThe right of the patient to know the medical risks surrounding the medical intervention is one of the most prominent rights based on the principle of "physical safety", which has undergone several stages of development until it reached the development of the patient's independence in making medical decision without relying on the doctor, The patient's prior informed consent is informed of his / her medical condition. We will study this development in accordance with the French March 4, 2002 legislation on the rights of patients in the health system, whether it was earlier and later. We will highlight the development of the patient's right to "know the medical risks surrounding medical intervention" The legislation and its comparison with th
... Show MoreExtension of bandwidth for high reflectance zone for the spectral region (8-14pm) was studied adapting the concept of contiguous and overlapping high reflectance stacks. Computations was carried out using the modified characteristic matrix theory restricted to near-normal incidence of light on dielectric , homogenous and isotropic symmetrical stack. Certain precautions must be taken in the choice of stacks to avoid deep —reflectance minima from developing within the extended high reflectance region. Results illustrate that the techniques of extending the high reflectance regions are applicable not only to mirrors , but also to short-and long-edge filter and to narrow band pass filters.