Heat pipes and two‐phase thermosyphon systems are passive heat transfer systems that employ a two‐phase cycle of a working fluid within a completely sealed system. Consequently, heat exchangers based on heat pipes have low thermal resistance and high effective thermal conductivity, which can reach up to the order of (105 W/(m K)). In energy recovery systems where the two streams should be unmixed, such as airconditioning systems of biological laboratories and operating rooms in hospitals, heat pipe heat exchangers (HPHEs) are recommended. In this study, an experimental and theoretical study was carried out on the thermal performance of an air‐to‐air HPHE filled with two refrigerants as working fluids, R22 and R407c. The heat pipe he

Radiation therapy plays an important role in improving breast cancer cases, in order to obtain an appropriateestimate of radiation doses number given to the patient after tumor removal; some methods of nonparametric regression werecompared. The Kernel method was used by Nadaraya-Watson estimator to find the estimation regression function forsmoothing data based on the smoothing parameter h according to the Normal scale method (NSM), Least Squared CrossValidation method (LSCV) and Golden Rate Method (GRM). These methods were compared by simulation for samples ofthree sizes, the method (NSM) proved to be the best according to average of Mean Squares Error criterion and the method(LSCV) proved to be the best according to Average of Mean Absolu

It is well known that the rate of penetration is a key function for drilling engineers since it is directly related to the final well cost, thus reducing the non-productive time is a target of interest for all oil companies by optimizing the drilling processes or drilling parameters. These drilling parameters include mechanical (RPM, WOB, flow rate, SPP, torque and hook load) and travel transit time. The big challenge prediction is the complex interconnection between the drilling parameters so artificial intelligence techniques have been conducted in this study to predict ROP using operational drilling parameters and formation characteristics. In the current study, three AI techniques have been used which are neural network, fuzzy i

Radial density distribution function of one particle D(r1) was calculated for main orbital of carbon atom and carbon like ions (N+ and B- ) by using the Partitioning technique .The results presented for K and L shells for the Carbon atom and negative ion of Boron and positive ion for nitrogen ion . We observed that as atomic number increases the probability of existence of electrons near the nucleus increases and the maximum of the location r1 decreases. In this research the Hartree-fock wavefunctions have been computed using Mathcad computer software .

In this study, the global solar radiation for the locations of fourteen Iraqi metrological stations was studied and calculated. This was performed because most of the Iraqi stations lack solar radiation measuring devices. The equation postulated by Angström (1924) and modified by Prescott (1940) was utilized for the estimation of the solar radiation for the fourteen Iraqi metrological stations depending on sunshine duration measurements of these stations. Empirical constants of Angstrom-Prescott equation that are adopted by the Food and Agriculture Organization (FAO) were used for obtaining the results. The utilized data reported in this study were taken from the Republic of Iraq Meteorological Office (RIMO). The calculations and diag

The current study is concerned with the analysis of spatial and temporal to death the elderly population in the city of Baghdad and at the level of administrative units Minor (districts and the areas) depending on the general population census of the province of Baghdad, data for 1997 and data from the Ministry of Health Department of Health and Vital Statistics for 2013.
The study showed differing age and quality of mortality rates at the level of administrative units of the study area, and notes the high mortality rates of elderly people of all age groups in 2013 compared to 1997, and this is due to security conditions after the USA occupation, and the accompanying conditions have affected the increase in mortality rates.