The present study explores numerically the energy storage and energy regeneration during Melting and Solidification processes in Phase Change Materials (PCM) used in Latent Heat Thermal Energy Storage (LHTES) systems. Transient two-dimensional (2-D) conduction heat transfer equations with phase change have been solved utilizing the Explicit Finite Difference Method (FDM) and Grid Generation technique. A Fortran computer program was built to solve the problem. The study included four different Paraffin's. The effects of container geometrical shape, which included cylindrical and square sections of the same volume and heat transfer area, the container volume or mass of PCM, variation of mass flow rate of heat transfer fluid (HTF), and temperatures difference between PCM and HTF were all investigated. Results showed that the PCMs in a cylindrical container melt and solidify quicker than the square container. The increase in mass flow rate and/or temperature difference decreases the time required for complete phase change. Paraffin's solidify quicker than they melt and store more energy than they release
In today's world, most business, regardless of size, believe that access to Internet is imperative if they are going to complete effectively. Yet connecting a private computer (or a network) to the Internet can expose critical or confidential data to malicious attack from anywhere in the world since unprotected connections to the Internet (or any network topology) leaves the user computer vulnerable to hacker attacks and other Internet threats. Therefore, to provide high degree of protection to the network and network's user, Firewall need to be used.
Firewall provides a barrier between the user computer and the Internet (i.e. it prevents unauthor
... Show MoreVanadium dioxide nanofilms are one of the most essential materials in electronic applications like smart windows. Therefore, studying and understanding the optical properties of such films is crucial to modify the parameters that control these properties. To this end, this work focuses on investigating the opacity as a function of the energy directed at the nanofilms with different thicknesses(1–100) nm. Effective mediator theories(EMTs), which are considered as the application of Bruggeman’s formalism and the Looyenga mixing rule, have been used to estimate the dielectric constant of VO2 nanofilms. The results show different opacity behaviors at different wavelength ranges(ultraviolet, visible, and infrared). The results depict that th
... Show MoreOne hundred thirty - five clinical specimens of urine, blood, teeth root canal and burns were obtained from patients in hospitals of Baghdad. The specimens were cultured on Pfizer Selective Enterococcus agar to purify Enterococci isolates. 20 E. faecalis isolates were identified biochemically by growing in 10Cº, 45Cº, 6.5% NaCl, at pH 9.6 and confirmed by VITEK. Determination of Vancomycin-Resistant E. faecalis isolates were done by the minimum inhibitory concentrations [MICs] using agar dilution method. Seventeen E. faecalis isolates were determined as Vancomycin-Resistant and Intermediate Resistant.
Extemporization is the ability of the actor to reflect his internal being. It gives a sort of confidence and an ability to show the personal countenance of the role away from tension and rigidity. By extemporization, it is possible to deal with and criticize the real living life so it is an intellectual, emotional, sensual, and perceptive process connected with the psychological energy and the emotional memory and all this goes under the control of the director and his instigations and instructions depending on what the text involves of intellectual, social and psychological motivators so it primarily depends on talent, chance and discussion. The research involves four chapters; the first contains the problem
... Show MoreIn recent decades, global obesity has increased significantly, causing a major health problem with associated complications and major socioeconomic issues. The central nervous system (CNS), particularly the hypothalamus, regulates food intake through sensing the metabolic signals of peripheral organs and modulating feeding behaviors. The hypothalamus interacts with other brain regions such as the brain stem to perform these vital functions. The gut plays a crucial role in controlling food consumption and energy homeostasis. The gut releases orexigenic and anorexigenic hormones that interact directly with the CNS or indirectly through vagal afferent neurons. Gastrointestinal peptides (GIP) including cholecystokinin, peptide YY, Nesf
... Show MoreTelevision is one of the best means of transmitting news, as it presents to us the events and facts in our homes in an integrated manner that depends in their formation on the two elements of sound and image, as they relate to the different emotions of each individual as long as he enjoys the blessings of hearing and sight, in addition to that the image is of great importance and is the basis of persuasion for the recipient, which is stronger An influence from the audio or readable word, at a time when the reader of the newsletter (the broadcaster) should have high performance and preventive skills and a distinguished profession in his work, and the only authority that has the right to judge this is the viewer himself. The performance an
... Show MoreWe describe here a case of a 70 yr old man with long-standing rheumatoid arthritis who presented with low grade fever, fatigue, loss of appetite and weight, bluish discoloration of the fingers and patches of gangrenous skin on the fingers. There was intense pain in the fingers which prevented him from sleep. Along with these symptoms he developed loss of sensation in the dorsum of left foot, then left foot drop. We give below full account of the case and review of the causes of vasculitis. We want to emphasize on the importance of identifying vasculitis as one of the complications of rheumatoid arthritis and intensive treatment of this complication, as it is a life-threatening complication.
In this study, In2O3 was prepared by Solvothermal technique in autoclave device, which is a simple and inexpensive technique to indicate the best condition. The reaction took place between indium chloride and urea. In(OH)3 as-prepared annealing at 100°C and convert to In2O3 at annealing temperatures 300, 500, 700 °C for 90 min .The physical properties of nanoparticles were characterized by XRD, SEM, AFM, UV/Visible and FTIR spectroscopy measurements. The examination results of XRD for In2O3 powder annealed at different temperature showed the formation of a cubic phase of nanoparticles with high intensity of plane (222). The lattice constant decreases with the increase of annealing temperature (from 10.07 to 10.04 Ǻ). AFM indicated an
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