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%.
The main challenge of military tactical communication systems is the accessibility of relevant information on the particular operating environment required for the determination of the waveform's ideal use. The existing propagation model focuses mainly on broadcasting and commercial wireless communication with a highs transceiver antenna that is not suitable for numerous military tactical communication systems. This paper presents a study of the path loss model related to radio propagation profile within the suburban in Kuala Lumpur. The experimental path loss modeling for VHF propagation was collected from various suburban settings for the 30-88 MHz frequency range. This experiment was highly affected by ecological factors and existing
... Show Moreلم تولد الجماهيرية العالية للسينما من فراغ، إنّما تحققت من إيمان المتلقي العميق، بأن الفيلم أبعد من محاولة للترفيه، فالسينما هي فلسفة العصر، التي تتناول القضايا المهمة لتقدمها عبر حكايتها مؤطّرة بمنطق محدّد ومدفوعة ببناء عاطفي مؤثر، يهيئ المتلقي للاهتمام بهذه القضايا واستيعابها، والتغير المناخي واحد من أهم المواضيع التي بدأت السينما في الحقبة السابقة بتبنيها وتقديمها ضمن بنى حكائية تزيد من وعي المتل
... Show MoreIn this paper the reinforced materials manufactured from steel continues fibers are used in Aluminum matrix to build a composite material. Most of researches concentrated on reinforced materials and its position in the matrix according to its size and distribution, and their effects on the magnitude of different kinds of the stresses, so this paper presents and concentrate on the geometrical shape of reinforced material and its effects on the internal stresses and strains on the composite strength using FEM as a method for analysis after loaded by certain force showing the deference magnitudes of stresses according to the different geometrical shapes of reinforced materials.
Chilled ceilings systems offer potential for overall capital savings. The main aim of the present research is to investigate the thermal performance of the indirect contact closed circuit cooling tower, ICCCCT used with chilled ceiling, to gain a deeper knowledge in this important field of engineering which has been traditionally used in various industrial & HVAC systems. To achieve this study, experimental work were implemented for the ICCCCT use with chilled ceiling. In this study the thermal performances of closed wet cooling tower use with chilled ceiling is experimentally and theoretically investigated. Different experimental tests were conducted by varying the controlling parameters to investigate their effects
... Show MoreThe analytical study of optical bistability is concerned in a fully
optimized laser Fabry-Perot system. The related phenomena of
switching dynamics and optimization procedure are also included.
From the steady state of optical bistability equation can plot the
incident intensity versus the round trip phase shift (φ) for different
values of dark mistuning
12
,
6
,
3
,
1.5
0 , o
or finesse (F= 1, 5, 20,
100). In order to obtain different optical bistable loops. The inputoutput
characteristic for a nonlinear Fabry-Perot etalon of a different
values of finesse (F) and using different initial detuning (φ0) are used
in this rese
In this paper, a theoretical analysis of optimum bed thickness operates under mass transfer control for realizing a high efficiency and reaction conversion of an electrochemical reactor has been made based on flowthrough porous electrode (FTPE) configuration. Many models have been used to represent the optimum bed thickness by taking a look into previous works concerned and collecting all related information, data, and models. The parameters that affect the optimum bed thickness have been visualized and reviewed, and almost all of them have been examined by experimental data from different sources and based on the various models. It has been found that the increase in electrolyte flow rate, concentration, limiting current density, and sp
... Show MoreThe research aimed to diagnose and interpretation of impact nature between Communities of practice dimensions (participation and spreading knowledge, confidence, social capital build) deportation strategic change choices (reengineering business process, business re-structuring, business innovation) in construction companies in the Iraqi Ministry of Construction and Housing, the research tested 4 construction companies working in investing sector in Iraq, the research applied on a sample of 102 persons who participated in Communities of practice distributed in several administrative levels (directors, division directors, project directors and engineers) the research used questionnaire as a main tool for dat
... Show MoreA specific, sensitive and simple method was used for the determination of: vitamin B9 (Folic acid) in pure and pharmaceutical formulations using continuous flow injection analysis. The method is based on formation of ion pair compound between folic acid and ammonium molybdate in an aqueous medium to obtain a gray precipitate complex, using homemade; Ayah-6SX1-ST-2D solar cell CFI Analyzer. Optimum parameters was studied to increase the sensitivity for developed method. The linear range for the calibration graph was 0.01-0.6 mMol.L-1 of vitamin B9 and LOD was 131.994 ng/sample with correlation coefficient ( r ) of 0.9810, RSD% was lower than 0.1%, (n=9) for the determination of vitamin B9 at concentration (0.07and 0.5) mMol.L-1 respectiv
... Show MoreThe marketing of banking service is considered to be one of the impotent fields which showed a universal inebriates . He research showed the comparison between the application of marketing in ideas and application for loot government and private Iraqi bank. The research comets of four parts; Mythology / the concept and the importance of Banking Marketing / Research applichlion/ Conelnion and recommendation.
