This theoretical study examines the characteristics of a surface wave driven plasma monopole antenna using finite difference time domain method (FDTD) as well as commercial full wave simulator. The results show that the full wave simulator can be considered as an acceptable tool in simulation of a plasma antenna. Input impedance, radiation pattern, gain, efficiency and radar cross section of plasma antenna at plasma and collision frequency values are presented here using FDTD numerical method. Comparison between the achieved results with a conventional metallic antenna shows that the plasma antenna is an acceptable radiation tool in the first resonant region and can provide a dynamically reconfigurable antenna.

Background and Objective: Existing of fine clay in mines and small particles of copper have caused reduction in chemical and biologicalreactions of these source, also using them makes it impossible to used in mass leaching operation in hydrometallargy of copper.Materials and Methods: In this study colum bioleaching of minus 1 mm fraction size of agglomeration of column bioleaching operation were evaloated.Results: A column bioleaching test of agglomerated ore was run for 105 days along with a negative control using thymol as bactericide. At this stage,about 77.5% of copper was recovered while this amount in non-inoculated column was only 57%.Conclusion: The result showed that this procedure can be successfully used to obtain biologic copper in these resources.

In regard to wide piers, the pile group rather than single pile is used frequently to bear the loading of the structure in a particular arrangement; piles group composed of only one column of piles in the flow direction has a great effect on supporting the bridge deck. In this study, local scour at a single column arrangement of the piles group made up of four rows of piles characterized by different piles spacing was studied for clear-water conditions with two flow discharges of 20 and 35 l/s (the effect of increasing the flow depth with the same flow intensity). The results indicated that an increase in the flow depth not only greatly enhanced the scour depth and the width of the scour hole. Besides, the investigation of the relative flow depth on scour extent showed the need for revision in deep water conditions, as reported in the literature. The results of the pile group experiments revealed the noticeable impacts of piles spacing on the local scour. The bigger pile spacing caused a feeble interaction of wake-horseshoe vortices, leading to a decrease of the scour depth; the separate view of the scour holes was generated at individual piles. Finally, the results were compared with commonly used comprehensive models. The findings of this study can be applied for the appropriate selection and positioning for the countermeasure of the scour at bridge piers...

Guidance is necessary for leadership and Imamate, and the guides, with divine care and attention, consciously and steadfastly fulfill their role in this position. What is certain is that the necessity of such guidance includes special knowledge and understanding of all aspects of the world and the characteristics of human beings. The title of the column of light is indicative of one of the foundations and methods of the impeccable Imam's knowledge of hidden and unseen matters. Understanding the truth of the column of light and explaining its function and the reasons for using this title by the institution of Imamate are the three main axes of the present study, which has been organized in an analytical method and library approach. The result of the insight into the transferred knowledge in this area is that the column of light is a reality that signifies the relationship of angels with the center of guidance to achieve the issue of the Imam's knowledge to the actions of the servants, and therefore the internal guidance of the believers by the Imam, alongside other forms of guidance. The two issues of the Holy Spirit and challenge (Taḥaddī) also play a complete role in shaping the third side of the triangle, namely the column of light, and in fact, on the one hand, it provides the Imam with the benefit of a pure and sacred spirit and creates the ground for the angels' communication with them, and on the other hand, it provides the spiritual vessel of the Imam as a channel for the spiritual evolution of the believers.

Chador- malu mineral processing plant includes three similar and parallel production lines. The nominal production capacity of each line has been designed to be 1,700,000 tons per year. The final products are magnetite, hematite and phosphate concentrates. The magnetite and hematite concentrate productions are 216 and 50 tones per hour for each production line respectively. The hematite concentrate is produced in a flotation circuit including rougher, scavenger and cleaner stages. Sala mechanical flotation cells were employed in all stages. To make a prediction of results of column flotation of hematite, a laboratory test was designed. The laboratory column cell diameter and height were 7.6and 153cm respectively. Bubbles were generaled by using a vertical Internal sparger. A wash water system was employed to clean overflow concentrate. Hydrodynamic parameters of column cell were estimated by water manometers. Effects of parameters such as under flow rate, gas rate, wash water rate and collector-frother dosages on metallurgical and hydrodynamic cell performance were determined. The reasonable cell performance values for under flow rate, gas rate, wash water rate and collector-frother dosage were obtained. which is very close to plant production performance. It is predicted that by employing these results, all nine stages in mechanical flotation cell can be replaced with one column flotation stage.