The present work deals with an experimental investigation of charging and discharging processes in thermal storage system using a phase change material PCM. Paraffin wax was used as the PCM which is formed in spherical capsules and packed in a cylindrical packed column which acted as an energy storage system. Air was used as the heat transfer fluid HTF in thermal storage unit. The effect of flow rate and inlet temperature of HTF on the time of charging and discharging process were studied. The results showed that the faster storage of thermal energy can be made by high flow rate of heat transfer fluid HTF and high inlet temperature of heat transfer fluid. It was found that at 65°C HTF inlet temperature, the melting and solidification processes accelerated by 27.9% and 57.14% respectively, when the flow rate was increased from 9 to 24 L/s. Also, when the HTF inlet temperature changed from 65°C to 80°C, the time needed to complete melting process decreased by 38.8%.
Since the law is the tool for implementing the state’s public policies, it is natural that its provisions (or at least some of them) seek to preserve human dignity as the source on which all rights and freedoms are based. One of the examples of humanizing the provisions of the law in France is what is known as the winter truce. What is this truce, what are the justifications for granting it, what is its historical origin, how did the legislative treatment of it develop, what are the similarities and differences between it and other legal periods included in French law, what is the scope of its application, and what are the effects resulting from it. These questions and others are what we will try to answer through this research.
In this work the parameters of plasma (electron temperature Te,
electron density ne, electron velocity and ion velocity) have been
studied by using the spectrometer that collect the spectrum of
plasma. Two cathodes were used (Si:Si) P-type and deposited on
glass. In this research argon gas has been used at various values of
pressures (0.5, 0.4, 0.3, and 0.2 torr) with constant deposition time
4 hrs. The results of electron temperature were (31596.19, 31099.77,
26020.14 and 25372.64) kelvin, and electron density (7.60*1016,
8.16*1016, 6.82*1016 and 7.11*1016) m-3. Optical properties of Si
were determined through the optical transmission method using
ultraviolet visible spectrophotometer with in the range
(
(1)
this research concern with material function subject by using it in Baghdad education in formational places , because it considered as one of the most important spaces which needs a material presentation for the interior consistings that shares with prepairing the right mode for thos who use these spaces, regarding to that this research includes four chapters: Chapter one: concern with the research problem represented by the following question: can we use the material to place the hole spaces of information place ? So the aim of the research seems very obvious in functioning the material these places, and to take a close view on the importance of the research the theory , implementation and objective limits also concerning the terminolog
... Show More
The ejector refrigeration system is a desirable choice to reduce energy consumption. A Computational Fluid Dynamics CFD simulation using the ANSYS package was performed to investigate the flow inside the ejector and determine the performance of a small-scale steam ejector. The experimental results showed that at the nozzle throat diameter of 2.6 mm and the evaporator temperature of 10oC, increasing boiler temperature from 110oC to 140oC decreases the entrainment ratio by 66.25%. At the boiler temperature of 120oC, increasing the evaporator temperature from 7.5 to 15 oC increases the entrainment ratio by 65.57%. While at the boiler temperature of 120oC and
... Show More
(1)
(8)
(6)
The study of the laptop computer table is one of the important studies at the present time due to the importance of electronic computers that are used in work sites and homes for very long hours, so one of the most important basics of caring for the comfort of the user lies in the design of the laptop table in different shapes and sizes and multiple functions in addition to calculating the measurements of the human body and the extent Its compatibility with the design and measurements of laptop computer tables by taking into account the calculations and measurements of the dimensions of the user's body of all ages and their consistency and use with the general measurements of the tables and the importance of research comes through the es
... Show More
The electric energy is one of the most important renewable energies used in the world as it is the main source for sustainable development and economic development through its use in (production, transport and distribution), and in Iraq, the electric power sector has suffered from many problems and obstacles, as providing electric current is one of the most prominent difficulties and challenges That successive governments and residents have faced since the early nineties of the last century and are still ongoing, and that Iraq has all the climatic conditions for developing the work of the electricity system from renewable energies such as solar and hydroelectric energy, as well as gas fields that have become a Basic pillar of pow
... Show More
(1)