Foundations supporting reciprocating engines, radar towers, turbines, large electric motors, and generators, etc. are subject to vibrations caused by unbalanced machine forces as well as the static weight of the machine. If these vibrations are excessive, they may damage the machine or cause it not to function properly. In the case of block foundation, if changes in size and mass of the foundation do not lead to a satisfactory design, a pile foundation may be used. In this study, the dynamic response of piles and pile Groups in dry sand is investigated experimentally. The analysis involves the displacement response under harmonic excitation. In addition, a numerical modeling by using finite element method with a three-dimensional formulation is adopted to simulate the experimental model. The results of the numerical model showed that a good agreement is achieved between the predicted dynamic response and that measured from the experimental model.
Phase change materials are known to be good in use in latent heat thermal energy storage (LHTES) systems, but one of their drawbacks is the slow melting and solidification processes. So that, in this work, enhancing heat transfer of phase change material is studied experimentally for in charging and discharging processes by the addition of high thermal conductive material such as copper in the form of brushes, which were added in both PCM and air sides. The additions of brushes have been carried out with different void fractions (97%, 94% and 90%) and the effect of four different air velocities was tested. The results indicate that the minimum brush void fraction gave the maximum heat transfer in PCM and reduced the time
... Show MoreThe efficient behavior of a low-concentrating photovoltaic-thermal system with a micro-jet channel (LCPV/T-JET) and booster mirror reflector is experimentally evaluated here. Micro-jets promote the thermal management of PV solar cells by implementing jet water as active cooling, which is still in the early stages of development. The booster mirror reflector concentrates solar irradiance into solar cells and improves the thermal, electrical, and combined efficiencies of the LCPV/T-JET system. The LCPV/T-JET system was tested under ambient weather conditions in the city of Bangi, Selangor, Malaysia, and all data was recorded between 10:00 a.m. and 4:00 p.m. Parametric studies were conducted to compare the performance of the LCPV/T-JET system
... Show MoreElectrochemical Grinding (ECG) process is a mechanically assisted electrochemical process for material processing. The process is able to successfully machine electrically conducting harder materials at faster rate with improved surface finish and dimensional control. This research studies the effect of applied current, electrolyte concentration, spindle speed and the gap between workpiece and tool on hardness and material removal rate during electrochemical grinding for stainless steel 316. The characteristic features of the electrochemical grinding process are explored through Taguchi-design-based experimental studies. The better hardness can be obtained at 10 A of the current, 150 g/l of the electrolyte concentration, 0.3 mm of gap an
... Show Morethe use of diffrent concectration of Na and Mg ions were shown to causes in increase in the bindings at oncentration
This paper is summarized with one of the applications of adsorption behavior; A UV-Vis method has been applied to survey the isotherm of adsorption. Results for experimental showed the applicability of Langmuir equation. The effect of temperature on the adsorption of cobalt (II) Complex by bentonite surface was studied. The results shown that the amount of adsorption was formed to increase, such as the temperature increase (Endothermic process). Cobalt (II) Complex has adsorption studies by bentonite surface at different pH values (1.6-10); these studies displayed an increase in adsorption with increasing pH. ∆G, ∆H, and ∆S thermodynamic functions of the cobalt (II) Complex for their adsorption have been calculated
This paper is summarized with one of the applications of adsorption behavior; A UV-Vis method has been applied to survey the isotherm of adsorption. Results for experimental showed the applicability of Langmuir equation. The effect of temperature on the adsorption of cobalt (II) Complex by bentonite surface was studied. The results shown that the amount of adsorption was formed to increase, such as the temperature increase (Endothermic process). Cobalt (II) Complex has adsorption studies by bentonite surface at different pH values (1.6-10); these studies displayed an increase in adsorption with increasing pH. ΔG, ΔH, and ΔS thermodynamic functions of the cobalt (II) Complex for their adsorption have been calculated.
Erbium, as optical probe, doped silicate sol-gel glass with
different Er concentrations was formed by wet chemical synthesis
method using ethanol, water and tetraethaylorthosilicate
[Si(OC2H5)4] precursor. Erbium ions were incorporated into silica
sol-gel matrix via dissolution of Erbium chloride solution into the
initial Si(OC2H5)4 precursor sol. Aluminum (Al) as a co-dopant was
added to the final precursor in the form of Aluminum chloride
(AlCl3) solution. The prepared samples were analyzed using atomic
absorption analysis, X-ray diffraction and spectroscopic tests. The
experimental results concerned with the transmission spectra suggest
that the final samples have a good transparency and homogeneity.
A
Virtual reality technology is the science of the embodiment of things and move spontaneously among non-real from one place to another with the full sense of the form, touch, sound, enables the user tried out and deal with it, like a real natural world and open up new worlds for human ambitious to let him overlooks the supposed world. Internet has become part of our daily lives, especially with the presence of mobile devices; that revolutionized the world of social networking. Access to information and build relationships change in the era of digital technology. The woman is not in isolation from this era; she found to herself a wide area for the production of ideas.
When we talk about woman in the modern means of communication, this a
تنتاب العلاقةَ الأمريكية الإيرانية تجاذباتٌ ومشاحنات أدخلت العالم في حالة من الغموض السياسي، وجعلت بعض المراقبين والمحللين السياسيين لا يستبعدون توجيه الولايات المتحدة الأمريكية أو إسرائيل ضربة عسكرية لإيران، إذ يرى المدقق في واقع تلك العلاقة المضطربة: أن الأمور كلما بلغت حافة الهاوية عادت من جديد إلى ساحة الحوار والمفاوضات، ويبدو: أن الإستراتيجية الأمريكية التي يتبعها الرئيس (باراك أو
... Show MoreBackground: For various reasons, inguinal hernia repair under local anaesthesia is not well accepted to both patients and surgeons. The patients fear from pain and surgeons need full relaxation and co-operation to do successful hernia repairMethods: purpose of this study is to evaluate the effectiveness of local anaesthesia in inguinal hernia repair.prospective study was made from January 2011-0ctober 2013 , on a total of 50 patients with inguinal hernia operated on under local anaesthesia. Patients were selected primarily on the basis of their willingness to accept the procedure after the technique was described to them.Results: In this study 50 patient and 58 herniorrhaphies done for them during a period of about 34months were evaluate
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