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Author: طه احمد الطيار عبد المحسن سعد الله شهاب مي عبد الحافظ العلاف
Journal: Tikrit Journal of Engineering Sciences مجلة تكريت للعلوم الهندسية ISSN: 1813162X 23127589 Year: 2008 Volume: 15 Issue: 4 Pages: 45-62
Publisher: Tikrit University جامعة تكريت

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Abstract

To define the biological features of phytoplankton in Mosul Dam Lake, monthly samples were collected along a year from September 2003 to August 2004. Consisting thermal stratification and turn over periods from four locations in the main lake and another location in the regulating lake. Total numbers of algae reached 2300 cell/ml in the main lake and 1100cell/ml in the regulating lake. Bacillariophyta were dominant with a maximum number of 1400 cell/ml in autumn. Chlorophyta were dominant in autumn also with 550 cell/ml. Ten genus of Chlorophyta were appeared in this water body: Cosmarium, Chlorella, Spirogyra, Scendesmus, Pediastrum, Tetraedron, Quadrigula, Ankiseradosm, Pandorina, and Straurastrum. Seven genus of Bacillariophyta were noticeable. Some genus of Cyanophyta was recorded as Aphanocapsa. In addition some Euglenophyta spp. were occurred in the main lake and the regulating lake also. On the basis of these algae abundance, the lake is undergoing cultural Eutrophication. It has passed in mesotrophic state (the middle trophic state of Eutrophication). Some genera which were appeared are the indication of eutrophic state.Total plate count bacteria ranged from 400-1700 cell/ ml in the main lake and 200-950 cell/ml in the regulating lake were also recorded. Coliform bacteria were founded with most probable number reached 460 cell/100ml in the main lake and 150 cell/100ml in the regulating lake. Therefore, the lake water is classified as moderate pure and considering a good source of raw water supply with all treatment units and safe for swimming and recreational uses.

تضمن البحث وصف بعض الخصائص البيولوجية لبحيرة سد الموصل المتكونة نتيجة حصر مياه نهر دجلة شمال مدينة الموصل للتعرف على حالة الإثراء الغذائي للبحيرة. تم جمع نماذج شهرية ولمدة سنه كاملة ابتداء من شهر أيلول 2003 ولغاية شهر آب 2004 ,مُتضمنا فترة التطبق الحراري وفترة الانقلاب الخريفي ومن أربعة مواقع في البحيرة الرئيسية وموقع خامس في البحيرة التنظيمية. أظهرت النتائج أن أعداد الطحالب الكلية بلغ 2300 نبته/ مللتر في البحيرة الرئيسية و1100 نبته/ مللتر في البحيرة التنظيمية. وكانت الدايوتومات والطحالب الخضر هي السائدة خلال فترة الدراسة , حيث وصلت أعداد الدايوتومات إلى أقصاها في فصل الخريف 1400 نبته/مللتر. وأعداد الطحالب الخضر إلى 550 نبته/ مللتر في فصل الخريف أيضا. تم ملاحظة عشرة أجناس من الطحالب الخضر: Cosmarium، Chlorella، Spirogyra، Scenedesmus،Pediastrum،Tetraedron، Quadrigula ، Ankiseradosm ، Pandorina ، Straurastrum ولم يكن أي منها سائدة. تم تشخيص سبعة أجناس من الدايوتومات , كما تم ملاحظة بعض أجناس الطحالب الخضر المزوقة في البحيرة الرئيسية والبحيرة التنظيمية, وشُخصٌت أجناس من النوع Euglenophyta في مواقع الدراسة المختلفة. إن بعض أجناس الطحالب التي شُخصت توجد في ألمياه ألملوثه, مما يدل على تدهور حالة البحيرة بيولوجيا. وبالاستناد إلى أنواع الطحالب الموجودة في البحيرة الرئيسية والبحيرة التنظيمية فأن البحيرة تتقدم في عملية الإثراء الغذائي Mesotrophic. تراوحت أعداد البكتريا الكلية بين 400 إلى1700خليه/مللتر في مياه البحيرة الرئيسية وما بين 200 الى 950خليه/مللتر في مياه البحيرة التنظيمية, فضلا عن تشخيص بكتيريا الكوليفورم بأعداد بلغت 460 خليه/100 مللتر في مياه البحيرة ألرئيسيه و150خليه/100مللتر في مياه البحيرة التنظيمية, وهو ما يصنف مياهها على إنها متوسطة النقاوة. ويجعلها صالحة كمصدر للمياه الخام في محطات الإسالة التي تتطلب مراحل التصفية التقليدية الكاملة كما ويجعلها صالحة للسقي و للسباحة في الوقت الحاضر.


Article
STABILITY ANALYSIS AND DESIGN OF PRESSURE CONTROL SYSTEM
تحليل الإستقرارية وتصميم منظومة السيطرة على الضغط

Authors: Aziz Abdul-Karim --- Dr. Salam K. Hassan --- Dr. Duraid Fadhel Ahmed
Journal: Tikrit Journal of Engineering Sciences مجلة تكريت للعلوم الهندسية ISSN: 1813162X 23127589 Year: 2008 Volume: 15 Issue: 3 Pages: 64-76
Publisher: Tikrit University جامعة تكريت

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Abstract

The performance of pressure control system and stability analysis was studied for different types of controllers. A theoretical model for closed-loop system is developed and dynamic behavior of the control system was studied by introducing a step change in the pressure of the inlet stream. The results show that the theoretical response is faster than the experimental response due to the lags of the control valve and measuring elements. The pressure control system is stable for all conditions and for different control action because the real parts of roots of characteristics equation are negative but the response at PID controller is oscillatory stable. when PID controller used the response is improve due to eliminate the offset and stabilizing effect of derivative allow the proportional gain to be increased and increasing the speed of response compared to proportional and proportional-integral controllers.

KEYWORDS: Pressure Control, Stability, PID Control.

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Article
EFFECT OF NOISE DISTURBANCES ON THE RESPONSEOF MEASURING DEVICES
تأثير توزيع الضوضاء على الاستجابة لأجهزة القياس

Authors: K. T. Rashed --- Dr. G. M. Alwan
Journal: Tikrit Journal of Engineering Sciences مجلة تكريت للعلوم الهندسية ISSN: 1813162X 23127589 Year: 2008 Volume: 15 Issue: 2 Pages: 50-61
Publisher: Tikrit University جامعة تكريت

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Abstract

The present work studies the effect of noise on the dynamic response of pH, conductivity and thermocouple sensors which used into several industrial processes.
Thermocouple would be proven had more stability against noise than conductivity and pH meter. The effect of noise on process signals could be condensate as low as possible by using suitable model of filter especially when the sensors were implemented to a digital computer

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Article
STUDY THE CREEP OF TUBULAR SHAPED FIBER REINFORCED COMPOSITES

Author: Dr. Najat j. Salah Dr. Adnan A. Abdul Razak , Hussein Ali Hamid AL-Abdly Hassen Sh. Majdi
Journal: Tikrit Journal of Engineering Sciences مجلة تكريت للعلوم الهندسية ISSN: 1813162X 23127589 Year: 2008 Volume: 15 Issue: 4 Pages: 27-44
Publisher: Tikrit University جامعة تكريت

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Abstract

In present work tubular –shaped fiber reinforced composites were manufactured by using two types of resins ( Epoxy and unsaturated polyester) and separately reinforced with glass, carbon and kevlar-49 fibers (filament and woven roving), hybrid reinforcement composites of these fibers were also prepared. The fibers were wet wound on a mandrel using a purposely designed winding machine, developed by modifying an ordinary lathe, in winding angle of 55 for filament. A creep test was made of either the full tube or specimens taken from it. Creep was found to increase upon reinforcement in accordance to the rule of mixture and mainly decided by the type of single or hybridized fibers. The creep behavior, showed that the observed strain tends to appear much faster at higher temperature as compared with that exhibited at room temperate. The creep rate also found to be depending on fiber type, matrix type, and the fiber /matrix bonding. The creep energy calculated from experimental observations was found to exhibit highest value for hybridized reinforcement.

في البحث الحالي تم تصنيع مواد متراكبة أنبوبيه باستخدام نوعين من الراتنجات وهي الايبوكسي و البولي استر غير المشبع وتم تسليح هذه الراتنجات بالألياف بصوره منفردة حيث استخدمت ألياف الزجاج, الكاربون و الكفلر49 (بشكل خيوط أو حصيره محاكه) كما تم استعمال هجين من هذه الألياف لاجل تسليح الراتنجات أيضا. تشمل عمليه تصنيع المتراكبات الانبوبيه بطريقه اللف الخيطي, تصميم و تصنيع قالب معدني للحصول على هذه الأشكال و بعدها تتم عمليه ترطيب الألياف أولا بأمرأرها خلال محلول الراتنج ثم لفها على قالب التشكيل باستخدام مخرطة حورت لهذا الغرض للحصول على الأشكال الانبوبيه المطلوبة و بزاوية لف 55 درجه للألياف .أظهرت اختبارت الزحف بان الانفعال في درجات الحراره العاليه اسرع بكثير عند مقارنته بتلك التي يظهرها بدرجه حراره الغرفه ، وهذا يحصل بصوره أساسيه بسبب ان جزيئات الماده البولميريه تكون اكثر حريه في الحركه في درجات الحراره العاليه واتي تودي الى سرعه حصول التشوهات في النماذج . ووجد كذلك ان معامل الزحف يعتمد على نوع الالياف ، نوع الراتنج وكذلك نوع التأصر بين الليف و الراتنج ، أعلى قيمه لطاقه الزحف المحسوبه من التجارب العمليه ظهرت عند أستخدام النماذج الهجينه .


Article
FEASIBILITY STUDY OF SEDIMENT FLUSHING FROM MOSUL RESERVOIR, IRAQ
الجدوى الفنية لعملية غسل الرسوبيات في خزان سد الموصل/العراق

Author: Thair Mahmood Al-Taiee
Journal: Tikrit Journal of Engineering Sciences مجلة تكريت للعلوم الهندسية ISSN: 1813162X 23127589 Year: 2008 Volume: 15 Issue: 2 Pages: 1-16
Publisher: Tikrit University جامعة تكريت

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Abstract

The Feasibility of sediment flushing from Mosul reservoir located northern iraq was conducted. Many upto date world criteria and indices for checking the efficiency of sediment flushing from reservoir which have been got through analyzing large amount of data from many flushed reservoirs in the world which were depended tested and applied in the present case study (Mosul Reservoir). These criteria and indices depend mainly on the hydrological , hydraulic and topographical properties of the reservoirs in-addition to the operation plan of the reservoirs. They gave a good indication for checking the efficiency of the sediment flushing process in the reservoirs. It was concluded that approximately the main criteria for the successful flushing sediment was verified in Mosul reservoir such as Sediment Balance Ratio (SBR) and the Long Term Capacity Ratio (LTCR),the shape factor of reservoir (W/L) and the hydraulic condition such as the percentage of (Qf/Qin) and (Vf/Vin). This gave an indication that the processes of flushing sediment in Mosul reservoir is probably feasible and may be applied in the future to maintain the water storage in the reservoir.
KEYWORDS: Flushing Sediment, Sluicing, Reservoirs

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Article
تحسين إعادة تنشيط المبادلات الأيونية السالبة
IMPROVING OF ANION EXCHANGERES REGENERATION

Author: د.مزهر مهدي إبراهيم شيماء علي حميد
Journal: Tikrit Journal of Engineering Sciences مجلة تكريت للعلوم الهندسية ISSN: 1813162X 23127589 Year: 2008 Volume: 15 Issue: 4 Pages: 1-13
Publisher: Tikrit University جامعة تكريت

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Abstract

In this study, Different basis [NaOH and KOH] of variable concentration are used to reactivate Anion exchangers employing different schemes .The Laboratory results showed large improvement in efficiency of these exchangers ( i.e operating time was increased from 12 to 42 hours ) .The results of this work showed that the environmental load (waste water) can be reduced greatly when using the proposed regeneration scheme .

تم دراسة عملية إعادة تنشيط عدة أنواع من المبادلات الأيونية السالبة ( الراتنجات السالبة ), إذ استخدمت القاعدة هيدروكسيد البوتاسيوم [KOH] بتراكيز وأنماط مختلفة لإعادة تنشيط المبادلات الأيونية السالبة , وبينت النتائج المختبرية تحسناً كبيراً في كفاءة هذه المبادلات لإزالة الأيونات غير المرغوبة , وكذلك تم استخدام القاعدة [NaOH] بتراكيز وأنماط مختلفة لرفع كفاءة المبادلات الأيونية السالبة . وقد تم زيادة وقت التشغيل من 12 الى 42 ساعة.بينت الحسابات المنجزة بأنه قد تم تقليل كمية القواعد والمياه القاعدية بنسبة تزيد عن 67% في حالة تطبيق نتائج البحث حقليا .

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Article
دراسة في المحاكاة النظرية لتحليل عمود فصل البنزين لمصنع انتاجالالكيل بنزين المستقيم باستخدام البرنامج الجاهز CHEMCAD
PROCESS SIMULATION OF BENZENE SEPARATION COLUMN OF LINEAR ALKYL BENZENE (LAB)PLANT

Authors: Omar Saed Latef --- Dr. Zaid A. Abdel-Rahman
Journal: Tikrit Journal of Engineering Sciences مجلة تكريت للعلوم الهندسية ISSN: 1813162X 23127589 Year: 2008 Volume: 15 Issue: 1 Pages: 17-29
Publisher: Tikrit University جامعة تكريت

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Abstract

CHEMCAD process simulator was used for the analysis of existing benzene separation column in LAB plant(Arab Detergent Company/Beiji-Iraq).
Simulated column performance curves were constructed. The variables considered in this study are the thermodynamic model option, top and bottom temperatures, feed temperature, feed composition & reflux ratio. Also simulated columns profiles for the temperature, vapor & liquid flow rates compositions, were constructed. Four different thermodynamic models options (SRK, TSRK, PR, and ESSO) were used, affecting the results within 1-25% variation for the most cases.
For Benzene Column (32 real stages, feed stage 14), the simulated results show that bottom temperature above 200 oC the weight fractions of top components, except benzene, increases sharply, where as benzene top weight fraction decreasing sharply. Also, feed temperature above 180 oC shows same trends. The column profiles remain fairly constant from tray 3 (immediately below condenser) to tray 10 (immediately above feed) and from tray 15 (immediately below feed) to tray 25 (immediately above reboiler). Simulation of the benzene separation column in LAB production plant using CHEMCAD simulator, confirms the real plant operation data. The study gives evidence about a successful simulation with CHEMCAD.

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Article
A STUDY OF PHASE EQUILIBRIUM OF H2S IN SEVERAL PHYSICAL SOLVENTS USING CHEMCAD SIMULATOR
دراسة اتزان الاطوار لغاز كبريتيد الهيدروجين (H2S) مع عدة مذيبات فيزياويةباستعمال برنامج المحاكاة الجاهز CHEMCAD

Author: Dr. Zaid A. Abdel-Rahman
Journal: Tikrit Journal of Engineering Sciences مجلة تكريت للعلوم الهندسية ISSN: 1813162X 23127589 Year: 2008 Volume: 15 Issue: 3 Pages: 38-48
Publisher: Tikrit University جامعة تكريت

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Abstract

CHEMCAD process simulator was used for the analysis of the literature experimental phase equilibrium data of H2S with three physical solvents (Sulfolane, Propylene Carbonate (PC), and N-Methyl-2-Pyrrolidone (NMP)) at different temperatures ( 298.15 oK , 323.15 oK, and 373.15 oK). Two thermodynamic models, Peng-Robinson (PR) and Soave-Redlich-Kwong (SRK), were used.
The equilibrium data of H2S- Sulfolane and H2S- Propylene Carbonate (PC) systems were successfully correlated using SRK thermodynamic model. The deviation was noticed only for H2S-Sulfolane system as the temperature increases to 373 oK, to give a deviation of less than 5% .
The thermodynamic models used in present study, PR, and SRK , built in CHEMCAD simulator and used as such without modification, fail to correlate the equilibrium data of H2S- NMP (N-Methyl-2-Pyrrolidone) system for all temperature range used.
Modifications of the thermodynamic models were performed by editing user defined binary interaction parameters (BIP) of the systems used, gives good results.

KEYWORDS
Vapor–Liquid Equilibria, H2S, Physical Solvents, CHEMCAD Simulator, Thermodynamic Models, Equation of state and correlation

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Article
ECONOMICAL DESIGN OF CIRCULAR FOOTINGS ADJACENT TO SLOPES ON SANDY SOILS
التصميم الإقتصادي للأسس الدائرية المجاورة للمنحدرات على الترب الرملية

Authors: وسام عامر علص --- ايمان موسى فرحان --- د. عدنان جايد زيدان
Journal: Tikrit Journal of Engineering Sciences مجلة تكريت للعلوم الهندسية ISSN: 1813162X 23127589 Year: 2008 Volume: 15 Issue: 3 Pages: 49-63
Publisher: Tikrit University جامعة تكريت

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Abstract

The analysis presented here introduces three optimization techniques namely, Hooke and Jeeves, Fletcher-Reeves and Davidon-Fletcher-Powell as applied to design of the circular footing adjacent to slopes. A computer program was developed to solve this design problem using the conventional structural design approach in conjunction with these methods, A simple study was performed to detect the sensitivity of the objective function to its design variables. A further parametric study was performed regarding the geometric configurations of the footing and loading conditions in order to provide the geotechnical engineer with some useful design curves. Hooke and Jeeves method has been proved to be very instructive in exposing the effect of the other methods.
It has been proved that the minimum cost of the circular footing increases with the increase of the load whereas it decreases as the angle of internal friction increases and the Dcl/B ratio (column diameter/diameter of footing).
Key words: optimization, conventional design, slope, circular footing, sandy soil.

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Article
ENHANCEMENT OF PHENOL REMOVAL EFFICIENCY IN DORA REFINERY WASTEWATER TREATMENT PLANT
تحسين كفاءة إزالة الفينول في محطة معالجة المياه الثقيلة في مصفى الدورة

Author: Dr. Salah F. Sharif
Journal: Tikrit Journal of Engineering Sciences مجلة تكريت للعلوم الهندسية ISSN: 1813162X 23127589 Year: 2008 Volume: 15 Issue: 3 Pages: 18-37
Publisher: Tikrit University جامعة تكريت

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Abstract

Because the sanctions imposed on Iraq by the United Nations, programmed maintenance and wearing parts replacement has not been performed according to schedules in DORA Refinery Wastewater Unit, which resulted in higher phenol content and BOD5 in effluents disposed to river. The investigations showed that two main reasons were behind this problem: Firstly, increased emissions of hydrocarbons in the complexity of refinery equipment and Secondly, the decreased efficiency of the aerators in the biological. During the last few months, phenol average concentration in the effluent, after biological treatment was found to be between 0.06-0.13 mg/L, while COD was exceeding 110 mg/L after treatment in the same period. Considerable enhancement, has been indicated recently, after the following performances: First: Recycling wastewater from some heat exchangers, and the segregation of low and high strength of wastewaters, Second: Minimizing emissions of hydrocarbons from fluid catalytic cracking and steam cracking, Third: Replacement of driving motors of the aerators in the biological treatment unit. After replacement of these units, a significant decrease in phenol concentration was obtained in purified water (0.03-0.05) mg/L and COD of 60 mg/L before the tertiary treatment. It is concluded that a better quality of effluents has been obtained after a series of emissions control and wastewater treatment unit equipment maintenance performances.

KEYWORDS
Waste water, aerator, phenolic compounds

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