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alkej-509
Prediction of Equilibrium Mixing Index and Optimum Mixing Time for Three solid materials in Fluidized Column
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     Equilibrium and rate of mixing of free flowing solid materials are found using gas fluidized bed. The solid materials were sand (size 0.7 mm), sugar (size0.7 mm) and 15% cast iron used as a tracer. The fluidizing gas was air with velocity ranged from 0.45-0.65 m/s while the mixing time was up to 10 minutes. The mixing index for each experiment was calculated by averaging the results of 10 samples taken from different radial and axial positions in fluidized QVF column 150 mm ID and 900 mm height.

     The experimental results were used in solving a mathematical model of mixing rate and mixing index at an equilibrium proposed by Rose. The results show that mixing index increases with increasing air velocity and mixing time until it reaches an optimum value then decrease to an equilibrium value. The results also show the dependency of the mixing index on the particle size of the tracer component.

      The statistical analysis of the obtained theoretical mixing index versus the experimental mixing index shows that the standard error is 0.92 % (about 1 %) with the correlation coefficient of 0.9857 and the total residual of 0.002 for the ninth observation of the mixing index (theoretical versus experimental) over 95% confidence level.

 

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Publication Date
Wed Jul 01 2020
Journal Name
Iop Conference Series: Materials Science And Engineering
Increasing the Setting Time of Local Gypsum (Joss) by the Use of TGP additive
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Abstract<p>This research presents a study of using an additive for the objective of increasing the setting time of a material used in several aspects in the constructional field, this material is “Local-Gypsum” which is locally called “Joss”, and the additive used in this study is “Trees Glue Powder” denoted by “TGP”. Nine mixtures of Local-gypsum (joss) had been experimented in the current study to find their setting time, these mixes were divided into three groups according to their water-joss ratios (W/J) (0.3, 0.4 and 0.5), and each group was sub-divided into three sub-groups according to their TGP contents (0.0%, 0.3% and 0.6%). It was found that, when TGP is added with the </p> ... Show More
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Publication Date
Mon Oct 01 2012
Journal Name
Iraqi Journal Of Physics
The effect of the etching time on the electrical properties of nano structure silicon
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This work presents the study of the dark current density and the capacitance for porous silicon prepared by photo-electrochemical etching for n-type silicon with laser power density of 10mw/cm2 and wavelength (650nm) under different anodization time (30,40,50,60) minute. The results obtained from this study shows different chara that different characteristic of porous diffecteristics for the different porous Silicon layers.

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Publication Date
Sun Aug 30 2020
Journal Name
Journal Of Economics And Administrative Sciences
Comparison of the performance of some r- (k,d) class estimators with the (PCTP) estimator that used in estimating the general linear regression model in the presence of autocorrelation and multicollinearity problems at the same time "
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In the analysis of multiple linear regression, the problem of multicollinearity and auto-correlation drew the attention of many researchers, and given the appearance of these two problems together and their bad effect on the estimation, some of the researchers found new methods to address these two problems together at the same time. In this research a comparison for the performance of the Principal Components Two Parameter estimator (PCTP) and The (r-k) class estimator and the r-(k,d) class estimator by conducting a simulation study and through the results and under the mean square error (MSE) criterion to find the best way to address the two problems together. The results showed that the r-(k,d) class estimator is the best esti

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Publication Date
Mon Mar 13 2017
Journal Name
Journal Of Baghdad College Of Dentistry
A study to compare the internal fitness and marginal gap between single crowns and crowns within three-unite bridge of zirconia substructure fabricated by CAD-CAM system. (An In vitro study)
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ABSTRACT Purpose: the aim of this in vitro study was to compare the marginal gap and internal fitness between single crowns and the crowns within three-unit bridges of zirconium fabricated by CAD-CAM system. Materials and methods: A standard model from ivoclar company was used as a pattern to simulate three-units bridge (upper first molar and upper first premolar) as abutments used to fabricate stone models, eight single crowns for premolar and eight of three units bridges. Crowns and bridges fabricated by CAD-CAM system were cemented on their respective stone models then sectioned at the mid-point buccolingaully and misiodistaly and examined under stereomicroscope. Result: the marginal gap in premolar crowns and premolar within bridge we

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Publication Date
Mon Jun 19 2023
Journal Name
Journal Of Engineering
Study the Impact Behavior of the Prosthetic Lower Limb Lamination Materials Due to Low Velocity Impactor
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This work involves three parts ,  first part  is manufacturing different types of laminated below knee prosthetic socket materials with different classical laminated materials used in Baghdad center for prosthetic and orthotic (4perlon layers+2carbon fiber layer+4 perlon layers) , two suggested laminated materials(3perlon layers+2carbon fiber layer+3 perlon layers) and (3perlon layers+1carbon fiber layer+3 perlon layers) ) in order to choose perfect laminated socket . The second part tests (Impact test) the laminated materials specimens used in socket manufacturing in order to get the impact properties for each socket materials groups using an experimental rig designed especially for this purpose. The interface pressure between

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Publication Date
Sun Dec 09 2018
Journal Name
Baghdad Science Journal
A Comparative Efficiency Study of Two Adsorbent Materials to Remove Eosin Y Dye from Aqueous Solutions
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This study was done to find a cheap, available and ecofriendly materials that can remove eosin y dye from aqueous solutions by adsorption in this study, two adsorbent materials were used, the shells of fresh water clam (Cabicula fluminea) and walnut shells. To make a comparison between the two adsorbents, five experiments were conducted. First, the effects of the contact time, here the nut shell removed the dye quickly, while the C. flumina need more contact time to remove the dye. Second, the effects of adsorbent weight were examined. The nut shell was very promising and for all used adsorbent weight, the R% ranged from 94.87 to 99.29. However C. fluminea was less effective in removing the dye with R% ranged from 47.59 to 55.39. The thi

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Publication Date
Fri May 02 2025
Journal Name
مجلة كلية التربية الأساسية
التنبؤ بالانجاز الرقمي للوثب العالي بطريقة الفوسبري فلوب بدلالة قياسات أطوال الطرف السفلي للاعبين المتقدمين
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أن التركيب الهيكلي للجسم وقياساته الجسمية لها دورا ً كبيرا ً ومهما ً في الأداء الرياضي وتعتبر أحد أسس النجاح أو الفشل للفعالية التي يزاولها الرياضي ، كون توافر القياسات الجسمية الملائمة لمزاولة فعالية معينة تمنح الرياضي فرصة أكبر لإستيعاب الأداء الحركي السليم للمهارات ، ولكون فعالية الوثب العالي تعد واحدة من فعاليات ألعاب الساحة والميدان التي شملها التطور المتسارع في إنجازها لذا أرتأى الباحثون أن يتم أختي

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Publication Date
Wed Aug 30 2023
Journal Name
مجلة نسق
The Effectiveness of a Program Based on the Theory of the Five Minds in Developing Focused Reading and Extensive Reading Skills among Second-Year Middle School Students
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Publication Date
Fri Jan 01 2016
Journal Name
Applied Numerical Mathematics
Multiple time-dependent coefficient identification thermal problems with a free boundary
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Publication Date
Wed Jul 12 2023
Journal Name
Energies
Finite Time Disturbance Observer Based on Air Conditioning System Control Scheme
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A novel robust finite time disturbance observer (RFTDO) based on an independent output-finite time composite control (FTCC) scheme is proposed for an air conditioning-system temperature and humidity regulation. The variable air volume (VAV) of the system is represented by two first-order mathematical models for the temperature and humidity dynamics. In the temperature loop dynamics, a RFTDO temperature (RFTDO-T) and an FTCC temperature (FTCC-T) are designed to estimate and reject the lumped disturbances of the temperature subsystem. In the humidity loop, a robust output of the FTCC humidity (FTCC-H) and RFTDO humidity (RFTDO-H) are also designed to estimate and reject the lumped disturbances of the humidity subsystem. Based on Lyapunov theo

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