Experiments have been conducted to study the local and average heat transfer by mixed
convection for hydrodynamically fully developed, thermally developing and fully developed
laminar upward air flow in an inclined annulus with adiabatic inner cast iron tube and uniform
heated outer aluminum tube with an aspect ratio ( Ω = 0.72) and (L/Dh≈40) for both calming and
test sections). A wide range of Reynolds number from 859 to 2024 has been covered, and heat
flux has been varied from 159 W/m2 to 812 W/m2 (these values of heat flux and Reynolds
number gave Richardson number range from 0.03 to 0.٣٨), with angles of annulus inclination
φ =0o (horizontal position), φ =60o (inclined position), and φ =90o (vertical position). The hydrodynamically fully developed condition has been achieved by using aluminum annulus
(calming section) has the same dimensions as test section and has connected with it by Teflon
piece. The average Nusselt numbers have been correlated with the product of (Richardson
number and Reynolds number) and compared with available literature and showed satisfactory
agreement. The temperature and local Nusselt number profiles results have revealed that the
secondary flows created by natural convection have a significant effect on the heat transfer
process.
Inelastic transverse and longitudinal form factors of same parity have
been studied for B 10 nucleus in the frame work of the shell model for
many particles, by using He 4 as an inert core and the remaining
particles were distributed in 3 / 2 1 / 2 1p ,1p which form the model
space. The calculations of the present work based on the harmonic
oscillator potential with fixed size parameter (b). Here we use the
first order correction for the perturbation theory and the interaction
from Cohen-Kurath (CK). Adding the core-polarization effects to
form factors calculations gave a good agreement with the
experimental data. Calculations have been performed for the
transverse excited states of: (1 ,0 )at ( E 0.178M
The thermal properties (thermal transfer and thermal expansion coefficient) of the enhanced epoxy resin (MWCNT / x-TiO2) were studied by weight ratios with the values (0%, 3%, 5%, 7% and 10%) and a constant ratio of 3% of MWCNT. The ultrasonic technology was used to prepare the neat and composites which were then poured into Teflon molds according to standard conditions. Thermo-analyzer sensor technology was used to measure thermal transfer (thermal conductivity, thermal flow, thermal diffusion, thermal energy and heat resistance). The thermal conductivity, flow, and thermal conductivity values were increased sequentially by increasing the weight ratio of the filler while the results of stored energy values an
... Show MoreGH and IGF-2 were examined histologically in the present study on adult hens to learn more about the organs’ responses to GH and IGF-2. Cardiac protein synthesis is stimulated by GH and IGF-2, according to microscopic examination. The recent research found a considerable amount of adipose tissue in the cardiac muscle bundles, which is linked to the metabolic process. In addition, GH and IGF-2 were shown to promote protein synthesis and mitosis in liver and gizzard tissues, according to the research. In addition, the apoptosis, regeneration, and secretory activity of gizzard glands are increased by the aforementioned hormones.
This research aims to study the effect of microwave furnace heat on the mechanical properties and fatigue life of aluminum alloy (AA 2024-T3). Four conditions were used inside microwave furnace (specimens subjected to heat as dry for 30 and 60min. and specimens subjected to heat as wet (water) for 30 and 60 min.), and compared all results with original alloy (AA 2024-T3). Tensile, fatigue, hardness and surface roughness tests were used in this investigation. It is found that hardness of dry conditions is higher than wet conditions and it increases with increasing of time duration inside microwave furnace for dry and wet conditions. Also, tensile strength has the same behavior of hardness, but it increases with decreasing
... Show MoreThe current study examines the combined impacts of ultrasonic waves and nano silica (NS) on reducing the viscosity Sharqy Baghdad heavy crude oil with an API gravity of 20.32. NS of an average particle size of 59.93 nm and 563.23 m²/g surface area were produced utilizing the sol-gel technique from Iraqi sand. The XRD analysis indicates the existence of an amorphous silica, the SEM analysis showed that NS tends to agglomerate, and the FTIR spectra exhibited the presence of siloxane and silanol groups. In addition, the TGA analysis demonstrated a total weight loss of 15.62%, validating the thermal stability of the NS. The experiments included a study of the impact of ultrasonic power, exposure time, duty cycle, temperature, and the c
... Show MoreThe current study examines the combined impacts of ultrasonic waves and nano silica (NS) on reducing the viscosity Sharqy Baghdad heavy crude oil with an API gravity of 20.32. NS of an average particle size of 59.93 nm and 563.23 m²/g surface area were produced utilizing the sol-gel technique from Iraqi sand. The XRD analysis indicates the existence of an amorphous silica, the SEM analysis showed that NS tends to agglomerate, and the FTIR spectra exhibited the presence of siloxane and silanol groups. In addition, the TGA analysis demonstrated a total weight loss of 15.62%, validating the thermal stability of the NS. The experiments included a study of the impact of ultrasonic power, exposure time, duty cycle, temperature, and the c
... Show MoreObjective: The study aimed to screen the prepubertal children for idiopathic scoliosis at earlier stages, and find
out the relationship between idiopathic scoliosis and demographic data such as age, sex, body mass index,
heavy backpacks, and heart & lung diseases.
Methodology: A descriptive study was conducted on screening program for prepubertal children in primary
schools at Baghdad city, starting from 24th of February to the end of October 2010. Non- probability
(purposive) sample of 510 prepubertal children were chosen from primary schools of both sides of Al-Karkh
and Al-Russafa sectors. Data was collected through a specially constructed questionnaire format include (24)
items multiple choice questions, and
This study found that one of the constructive, necessary, beneficial, most effective, and cost-effective ways to meet the great challenge of rising energy prices is to develop and improve energy quality and efficiency. The process of improving the quality of energy and its means has been carried out in many buildings and around the world. It was found that the thermal insulation process in buildings and educational facilities has become the primary tool for improving energy efficiency, enabling us to improve and develop the internal thermal environment quality processes recommended for users (student - teacher). An excellent and essential empirical study has been conducted to calculate the fundamental values of the
... Show MoreThis research was aimed to study the exposure of Razzazah Lake to major hydrological changes in recent years as a result of natural climatic changes and drought, high evaporation in lake due to stop discharge from Habbaniyah Lake by Al- majera channel. During 2019, we collected surface water samples at three locations, and three samples from groundwater, in addition one samples from each location Imam Ali Drop and Sewage water of Karbala. The Results show that the heavy isotopes in lake and groundwater well are enriched during the warm period, and depleted during the cold period. Chemically, The dominant cations and anions in Al-Razzaza lake water are mainly of in Order Ca > Na > Mg and Cl>SO4 and the water
... Show MoreVariation order plays an important role in calculating the final cost and time. The paper aims to determine the causes of variation orders in projects performed between 2007-2014 in Erbil governorate projects. Data was collected from contract documents. Performed in the Erbil governorate projects from 2007-2014. The study seeks to identify the most significant causes of delays by assessing the common causes of delays in terms of frequency, severity and
important indices of owners, consultants and contractors related to&n
... Show More