In the present investigation two different types of fiber reinforced polymer composites were prepared by hand lay-up method using three different parameters (curing temperature, pressing load and fiber volume fraction). These composites were prepared from the polyester resin as the matrix material reinforced with glass fibers as first group of samples and mat Kevlar fibers as the second group, both with different volume fractions (4%, 8%, and 12%) of fibers. They were then tested by tensile strength and impact strength. The main objective in this study is to use Taguchi method for predicting the better parameters that give the better tensile and impact strength to the composites, and then preparing composites at these parameters and comparing them with the randomly used once. The experimental and analytical results showed that the Taguchi method was successful in optimizing the parameters that give the highest properties and it can find the most influential parameter regardless of the material used. Also it showed that the volume fraction was the most influential parameter on the tensile and impact strength. The difference between these composites was in the properties values and that the Kevlar composites have higher tensile and impact strength.
عرف العرب ، منذ القدم ، الأحجار الكريمة وعنوا بإقتناء أنواعا عديدة منها ، حيث كانت من أهم واردات سكان بلاد وادي الرافدين من السومريين والبابليين ثم الآشوريين ، كما عرفها المصريون القدماء وغيرهم من الشعوب القديمة ، فوجدت في قبورهم ومدافنهم وخزائن كنوزهم، مثل الياقوت الأحمر واللازورد واللؤلؤ . بالإضافة إلى ذلك فقد كان معدني الذهب والفضة من المعادن الوفيرة في هذه البلاد ، ولها الأولوية في صناعة الحلي.
Andalucía, dentro del mapa lingüístico español, es una región con muchas variaciones dialécticas. En muchos casos contiene una gran variedad de términos propios de la zona, ya que en esta misma zona se pueden observar muchas subdivisiones dialectales.
En este trabajo, hemos seguido dos tipos de fuentes:
- Directa: Se trata de conseguir la información por medio de cuestionarios distribuidos a informantes de edades y localidades diferentes.
- Indirecta: Consultando libros para conseguir información y datos básicos del tema, e información sobre las voces y nombres dialectales en la geografía estudiada.
This research has targeted four aims related to the social morals of university students in terms of psychological aspect and Islamic field; they had been achieved as follow:
- It had been sought in the social morals concept in Islam in relation to the Holy Quran and Hadith sources.
- It had been built standard for the social morals of the university students through analyzing Hadith and adopting focus ratio to identify the number of ten social moral items; and they have been subjected to the statistical analysis then finding the psychometric indicators to identify their truth and validity.
- To identify the ratios of social morals at a sample of Isla
هذا البحث يعنى بدراسة بعض المظاهر اللسانية التي اثارها فخر الدين الرازي في تفسيره الكبير المعروف ب(مفاتيح الغيب) والوقوف عندما يعرف في اللسانيات المعاصرة بالصفة الخطية للكلام وقد
وقد اثبت البحث ان الرازي اكد ما نسطلح عليه اليوم ب(الصفة الخطية للكلام) اي ان الدال ذو طبيعة سمعيه وانه يجري في الزمن وحده
انصبت هذه الدراسة على قياس جودة الخدمة، وبوجه خاص ماهية أبعاد جودة الخدمة التي يجري قياسها للوصول إلى مستوى جودة الخدمة. وتم التطبيق على خدمة التعليم العالي الخاص، حيث جرى اختيار عينة من طلبة جامعة خاصة لتعبئة الاستبانة الخاصة بالدراسة. وكان هناك 360استبانة تم تحليل البيانات فيها من خلال مؤشرات الإحصاء الوصفي، وتحليل الارتباط، وتحليل الانحدار المتعدد. وقد توصلت الدراسة إلى وجود علاقة ارتباط بين مستويات
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This study discussed the effects of doping with silver (Ag) on the optical and structural properties of
CdO nanoparticles at different concentrations 0, 1, 2, 3, 4, 5 wt% prepared by the precipitation method. The
materials were annealed at 550˚C for 1 h. The structural, topographical, and optical properties were
diagnosed by X-ray diffraction analysis, atomic force instrument, and visible and ultraviolet spectrometers.
The results show that the average diameter of the grains depends on the percentage of added silver to the
material, as the diameter decreased from 88.8 to 59.7 nm, and it was found that the roughness increased from
5.56 to 26.5. When studying the optical properties, it was noted that th
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the shear strength parameters of the treated and untreated gypsum soil under the effect of four soaking and drying cycles has studied in this paper, moreover examined the effect of wetting and drying cycles on the collapse potential of the soil and comparing between the behavior of the treated and untreated gypsum soil under the effect of the two conditions. Gypsum soil sample brought from Sawa lake in Al Muthana governorate with the content of gypsum 65.5%, the polyurethane polymer (PP) was used with different percentages 3, 6, and 10% to enhance the mechanical properties of gypsum soil, model was prepared to achieve four soaking and drying cycle to the samples before testing, this model consists of an Aluminum plate base with dimensions 7
... Show MoreCopper oxide nanoparticles (CuO NPs) were synthesized by two methods. The first was chemical method by using copper nitrate Cu (NO3)2 and NaOH, while the second was green method by using Eucalyptus camaldulensis leaves extract and Cu (NO3)2. These methods easily give a large scale production of CuO nanoparticles. X-ray diffraction pattern (XRD) reveals single phase monoclinic structure. The average crystalline size of CuO NPs was measured and used by Scherrer equation which found 44.06nm from chemical method, while the average crystalline size was found from green method was 27.2nm. The morphology analysis using atomic force microscopy showed that the grain size for CuO NPs was synthesized by chemical and green methods were 77.70 and 89.24
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Praise be to God, Lord of the Worlds, and prayers and peace be upon the Master of Messengers, Muhammad and his family
The good and pure and after his companions
God Almighty said: ( ) Do they not contemplate the Qur’an? If it had been from other than God, they would have found in it much discrepancy. God Almighty has made the well-being of people and their lives linked to faith in it. So what is the need of people today to return to the Book of their Lord so that they may return to the right path that God intended for His servants so that they may attain sustenance? Security and the good life. How could it not be, when many of the nations of the world no longer see security or stability because their leaders and politic
... Show MoreBeing the meeting points of the world different languages and out of a scholarly perspective, comparative literature represents a cultural leap as well as an artistic and intellectual development or a global literary movement of both prose and poetry. Such homogenous literary structure requires a systematic and coherent study of the literary output of the people different cultures and civilizations. It also represents the theoretical approach of the present study that debates a systematic comparison between Ghassan Kanafani’s All That's Left to You and William Faulkner’s. The Sound and the Fury. Within the perspective of the descriptive analysis approach, the present paper discusses th
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