In this work, the effect of vortex shedding on the solar collector performance of the parabolic trough solar collector (PTSC) was estimated experimentally. The effect of structure oscillations due to wind vortex shedding on solar collector performance degradation was estimated. The performance of PTSC is evaluated by using the useful heat gain and the thermal instantaneous efficiency. Experimental work to simulate the vortex shedding excitation was done. The useful heat gain and the thermal efficiency of the parabolic trough collector were calculated from experimental measurements with and without vortex loading. The prototype of the collector was fabricated for this purpose. The effect of vortex shedding at different operation condition

This study aims to suggest a technique for soil properties improvement of AL- Kadhimin shrine Minaret and to support the foundation, which has a tilt of roughly 80 cm from the vertical axis. The shrine of the AL- Kadhimin is made up of four minarets with two domes set in a large courtyard. The four minarets have skewed to varying degrees due to uncontrolled dewatering inside the shrine in recent years. However, the northeast minaret was the most inclined due to its proximity to the well placed inside shrine courtyard. When the well near the minaret is operated, the water level drops, increasing the effective stresses of the soil and causing differential settling of the minaret foundation. To maintain the minaret's foundation from potenti

     In this research, we study the dynamics of one parameter family of meromorphic functions . Furthermore, we describe the nature of fixed points of the functions in ,and we explain the numbers of real fixed points depending on the critical point . So, we develop some necessary conditions for the convergence of the sequence when .

The toxicity effect of some heavy metals (Lead, Cadmium, Copper, and Zinc) on the growth of alga Scenedesmus dimorphus which belongs to the Division of Chlorophyta was studied and depended on the total cell number . The growth rate and doubling time were also calculated accordingly in present of absent of the the heavy metals . There were differences in toxic effects of the metals (p<0.05) . The growth was decreased gradually with alga when exposured to Lead at 15,20 and 25 mg/l in comparison with the control , mean while 30 mg/l caused an acute decrease in growth . Treating the alga with 0.05,0.1,0.5 mg/l concentration of Cadmium the number of cells decreased while at 1 mg/l the effect was more pronounced . As for Copper the conc

The purpose of this study is designate quenching and tempering heat treatment by using Taguchi technique to determine optimal factors of heat treatment (austenitizing temperature, percentage of nanoparticles, type of base media, nanoparticles type and soaking time) for increasing hardness, wear rate and impact energy properties of 420 martensitic stainless steel. An (L₁₈) orthogonal array was chosen for the design of experiment. The optimum process parameters were determined by using signal-to-noise ratio (larger is better) criterion for hardness and impact energy while (Smaller is better) criterion was for the wear rate. The importance levels of process parameters that effect on hardness, wear rate and impact energy propertie

   The cytotoxic effect of different concentrations of Crude extracts of  Solanum melongena  , Curcuma longa and  Daucus carota  on  mice mammary adenocarcinoma cell line was  studied . The concentrations  used were 62.5 125 , 250, 500 Microgram/militer for 24,48 and 72 hour . These exracts were prepared by  using alcoholic and  hot water methods . The preliminary chemical tests revealed acidic pH of all  extracts. The results showed  a clear  toxic effect of all extracts in a time and dose –dependent manner . The Curcuma longa  had the highest effect on adenocarcinoma 94.61% , followed by Solanum melonga( 93.20%)   and the lowest effect was by Da

In this study, the effect of the thermal conductivity of phase change material (PCM) on the performance of thermal energy storage has been analyzed numerically. A horizontal concentric shell-and-tube latent heat thermal energy storage system (LHTESS) has been performed during the solidification process. Two types of paraffin wax with different melting temperatures and thermal conductivity were used as a PCM on the shell side, case1=0.265W/m.K and case2=0.311 W/m.K. Water has been used as heat transfer fluid (HTF) flow through in tube side. Ansys fluent has been used to analyze the model by taking into account phase change by the enthalpy method used to deal with phase transition. The numerical simulatio

Background: The aim of the study was to investigate the effect of surface treatments of zirconia (grinding and sandblast with 50μm, 100 μm) on shear bond strength between zirconia core and veneering ceramic. Material and methods: Twenty-eight presintered Y-TZP ceramic specimens (IPS e.max ZirCAD, Ivoclar vivadent) were fabricated and sintered according to manufacturer’s instructions. The core specimens were divided randomly in to 4 groups, group 1: no surface treatment, group2: zirconia specimens were ground with silicon carbide paper up to1200 grit under water cooling, group3: zirconia specimens were ground and sandblast with 100 μm alumina, group 4: zirconia specimens were ground and sandblast with 50 μm alumina. Surfa

This study aims to evaluate the effect of low power a semi-conductor He-Ne laser 4 mw power with 635 nm length on the growth and cell viability of dermatophyte Trichophyton mentagophytes. For this study, skin samples of 22 patents were collecting; those patients were suffering from dematophytsis caused by the dermatophytes, three isolates were diagnosed in dermatophytes group were T. mentagophytes.  Results showed that rays of semi-conductor laser with 635 nm wavelength of 4 mn power have affected the fungal growth T. mentagophytes (the ideal isolates) in sold media when exposed to laser radiation in different periods of 10-20 second duration, but the other two isolates gave negative results. The effects of He-Ne laser rays in dry w

    This work is an experimental study conducted to study the effects of iron oxide dust particles (Fe₂O₃) on the characteristics of DC discharge plasma in argon gas under vacuum. Electron temperature ( ) and electron density (n_e) were calculated by Boltzmann plots and Stark broadening, respectively. The results show that both the electron density and plasma frequency ( ) increased with the operating pressure. While,  and Debye length ( ) decreased with pressure. The glow discharge is more stable with the Fe₂O₃-dust particles; all dust plasma parameters have lower values  than those of the dust-free plasma.