In this study, a different design of passive air Solar Chimney(SC)was tested by installing it in the south wall of insulated test room in Baghdad city. The SC was designed from vertical and inclined parts connected serially together, the vertical SC (first part) has a single pass and Thermal Energy Storage Box Collector (TESB (refined paraffin wax as Phase Change Material(PCM)-Copper Foam Matrix(CFM))), while the inclined SC was designed in single pass, double passes and double pass with TESB (semi refined paraffin wax with copper foam matrix) with selective working angle ((30o, 45o and 60o). A computational model was employed and solved by Finite Volume Method (FVM) to simulate the air induced through the test room by SC effect. The governing equation of Computational Fluid Dynamic (CFD) model was developed by the effective heat capacity method equation to describe the heat storage and release from PCM-CFM. Practical and computational Results referred to increase in thermal conductivity of the paraffin wax that supported by CFM than 10 times, while the ventilation effect is still active for hours after sun set amount. The maximum ventilation mass flow rate with TESB collector was 36.651 kg/hr., when the overall discharge coefficient equals 0.371. Also, the experimental results referred to the best working angle range 45~60o, while the highest approaching temperature (between air and collector) was appeared for the double passes flat plate collector. Results gave higher heat storage efficiency 47% when the maximum solar radiation 780 W/m2 at 12.00 pm, and the energy summation through duration of charging time was 18460 kJ. Double passes SC at 60o angle presented the highest efficiency with value approaching to 73%, while TESB collector efficiency depicted highest efficiency value 70% at 12:00 pm.
In this paper, new concepts which are called: left derivations and generalized left derivations in nearrings have been defined. Furthermore, the commutativity of the 3-prime near-ring which involves some
algebraic identities on generalized left derivation has been studied.
In this research, nanofibers have been prepared by using an electrospinning method. Three types of polymer (PVA, VC, PMMA) have been used with different concentration. The applied voltage and the gap length were changed. It was observed that VC is the best polymer than the other types of polymers.
In this paper we generalize some of the results due to Bell and Mason on a near-ring N admitting a derivation D , and we will show that the body of evidence on prime near-rings with derivations have the behavior of the ring. Our purpose in this work is to explore further this ring like behavior. Also, we show that under appropriate additional hypothesis a near-ring must be a commutative ring.
Background: Otitis media with effusion is characterized by accumulation of fluid in the middle ear in absence of acute inflammation and it is the most common cause of acquired hearing loss in children, and may negatively affect language development failure of medical treatment of middle ear effusion frequently require myringotomy and tympanostomy tube insertion.
Objectives: To determine tympanostomy tube complications of tube in children with chronic otitis media with effusion who were treated with Shah Grommet tube insertion.
Methods: The Medical records of 162 ears of 87 children (52 male and 35 female) were reviewed respectively, the patients ages wer
... Show MoreBackground: Laparoscopic surgery for
appendicitis is now a well established and
advanced method of performing general surgical
procedures.
Objectives: To compare the outcome of
laparoscopic and open appendectomies in terms
of operative time, analgesic requirement,
postoperative complications, hospital stay, return
to normal activity and condition of scar.
Methods: This prospective study was carried
out from 1stMay 2008-1st January 2010, involving
110 patients (45 male and 65 female) with
features suggestive of acute appendicitis were
divided into 45 patients laparoscopic
appendectomy (LA) group and 65 patients open
appendectomy (OA) group, after taking informed
consent. LA was done with the
In this paper, we study, in details the derivation of the variational formulation corresponding to functional with deviating arguments corresponding to movable boundaries. Natural or transversility conditions are also derived, as well as, the Eulers equation. Example has been taken to explain how to apply natural boundary conditions to find extremal of this functional.
The continuous growth in technology and technological devices has led to the development of machines to help ease various human-related activities. For instance, irrespective of the importance of information on the Steam platform, buyers or players still get little information related to the application. This is not encouraging despite the importance of information in this current globalization era. Therefore, it is necessary to develop an attractive and interactive application that allows users to ask questions and get answers, such as a chatbot, which can be implemented on Discord social media. Artificial Intelligence is a technique that allows machines to think and be able to make their own decisions. This research showed that the dis
... Show MoreA numerical method for the calculation of the three-dimensional wake rollup behind symmetric wings with ground effect and its aerodynamic characteristics for steady low subsonic flow have been developed. A non-planar quadrilateral vortex-ring method with vortex wake relaxation iterative scheme for lifting surfaces is obtained. A computer program was build to treat wings with breaks, span wise trailing edge flaps, local dihedral angle, camber, twist and ground effect. Forces and moments are obtained from vector product of local velocity and vortex strength multiplied by density. The program has been validated for a number of configurations for which experimental data is available. Good agreement has been obtained for these configurations. Al
... Show MoreIn this paper two modifications on Kuznetsov model namely on growth rate law and fractional cell kill term are given. Laplace Adomian decomposition method is used to get the solution (volume of the tumor) as a function of time .Stability analysis is applied. For lung cancer the tumor will continue in growing in spite of the treatment.