The photo-electrochemical etching (PECE) method has been utilized to create pSi samples on n-type silicon wafers (Si). Using the etching time 12 and 22 min while maintaining the other parameters 10 mA/cm2 current density and HF acid at 75% concentration.. The capacitance and resistance variation were studied as the temperature increased and decreased for prepared samples at frequencies 10 and 20 kHz. Using scanning electron microscopy (SEM), the bore width, depth, and porosity % were validated. The formation of porous silicon was confirmed by x-ray diffraction (XRD) patterns, the crystal size was decreased, and photoluminescence (PL) spectra revealed that the emission peaks were centered at 2q of 28.5619° and 28.7644° for etching time 12 and 22 min, respectively. Studying the capacitance and resistivity during temperature increasing and decreasing for both itching times shows clearly that the prepared pSi as a thermal sensor is working better and in more selectivity for 20 min itching time
Low-temperature stratification, high-volumetric storage capacity, and less-complicated material processing make phase-changing materials (PCMs) very suitable candidates for solar energy storage applications. However, their poor heat diffusivities and suboptimal containment designs severely limit their decent storage capabilities. In these systems, the arrangement of tubes conveying the heat transport fluid (HTF) plays a crucial role in heat communication between the PCM and HTF during phase transition. This study investigates a helical coil tube-and-shell thermal storage system integrated with a novel central return tube to enhance heat transfer effectiveness. Three-dimensional computational fluid dynamics simulations compare the proposed d
... Show MoreInterested in many scholars and reseachers the subject of the media and means varied his roleinfluential in the definition of the public of issues and political, cultural, social and because of its spread wide and ability to address the people of all levels effect them in the formation consciousness of those issues and types of this awareness is an awareness of the tax, contribute to media formation consciousness tax through the definition of people what tax and importance of the role of its revenues to supplement the state budget by posting tax laws and regulations of applied and all what respect process account tax, to be in charge of the tax familiar enough about this, which avoid being cheated taxmisleading when rev
... Show MoreAll businesses seek to improve their levels of profits through various means, most notably their marketing channels, which ensure the delivery of their products to their customers in a safe manner in a timely manner. It considers losses to a minimum and that insurance companies place great interest in marine insurance losses because they often constitute huge amounts compared to other losses, hence the problem of research, which is centred on the type and size of the impact owned by the channel The Iraqi insurance company was chosen to be applied according to the intentional sample method because this company is closely related to the subject matter. The research has reached a set of conclusions, most notably that the choice of i
... Show Moreليكاند ازو جديد. 4-((3-formyl-2-hydroxyphenyl)diazenyl)-N-(5-methylisoxazol-3-yl)benzenesulfonamide, الليكاند المحضر استعمل لتحضير معقدات من ايونات معادن مختلفة مثل الكروم الثلاثي والمنغنيز الثنائي والحديد الثلاثي والبلاديوم الثنائي بنسب مولية (1:1) ( ليكاند : فلز) نتائج التشخيص للمركبات يتقنيات مطيافية الاشعة فوق البنفسجية الاشعة تحت الحمراء الرنين النووي المغناطيسي البروتوني والكربوني وطيف الكتلة والتحليل الدقيق للعناصر ومحتوى الفلز وال
... Show MoreSovereign wealth funds have attracted the attention of the governments of the oil and non-oil countries alike, with a variation of the size of those funds to those states, based on the size of the financial surpluses resulting from Alriadat oil or foreign reserves, or state revenues for other sovereign assets. Raj use these funds remarkably during the financial crises the world has seen, including the crisis of 2008-2007., And Iraq is a oil-producing countries, which has the third largest reserves of crude oil (Crude Oil) at the level of the Arab world and of 140 300)) million barrels after Saudi Saudi Arabia and the Islamic Republic of Iran, and the fourth reserves of crude oil in the world after issued Venezuela to the reserve
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Praise be to God, and may blessings and peace be upon the Messenger of God. As for:
The Noble Qur’an is the constitution of life, and a comprehensive educational approach that deals with individuals comprehensively, as it organizes worldly and eschatological life, and it is a curriculum concerned with organizing life starting with individuals and the family until the establishment of states, and from its comprehensiveness is reform, guidance and establishing boundaries. They have a disease in their hearts. They are exposed to this and are trying, by falsehood, to subjugate the Islamic world with man-made laws set by the West. Their aim is to distance people from
... Show MoreEstimation of mechanical and physical rock properties is an essential issue in applications related to reservoir geomechanics. Carbonate rocks have complex depositional environments and digenetic processes which alter the rock mechanical properties to varying degrees even at a small distance. This study has been conducted on seventeen core plug samples that have been taken from different formations of carbonate reservoirs in the Fauqi oil field (Jeribe, Khasib, and Mishrif formations). While the rock mechanical and petrophysical properties have been measured in the laboratory including the unconfined compressive strength, Young's modulus, bulk density, porosity, compressional and shear -waves, well logs have been used to do a compar
... Show MoreAlice Walker (1944) ranks among the greatest American writers of the twentieth century. Through her novels Meridian and the color Purple, Alice outlines many issues concerning the effect of authoritarian thinking upon its often innocent victims, and the possibility of meaningful, productive resistance. Walker's texts aim at giving a voice to those who have no voice especially those poor, rural black women who are robbed of power and the right to make decisions about their own lives by a range of forces standing against them. These texts also aim at clarifying how Walker's female protagonists, Meridian and Celia try to free themselves from oppression, misery , fear and underestimation
... Show MoreIn this investigation , borax (B) (additive I) and chlorinated paraffin (CP.) (additive II) ,were used as flame retardants for each of epoxy and unsaturated polyester resins in the weight ratios of 2,4,6, & 8% by preparing films of (130×130×3) mm dimensions. Also films of these resins with a mixture of [50%(B.)+50%(CP.)] (additive III) in the same weight ratios were prepared in order to study the synergistic effect of these additives on the flammability of the two resins . Three standard test methods were used to measure the flame retardation which are : 1-ASTM : D-2863 2-ASTM : D-635 3-ASTM : D-3014
... Show MoreIn this paper we generalize Jacobsons results by proving that any integer in is a square-free integer), belong to . All units of are generated by the fundamental unit having the forms
Our generalization build on using the conditions
This leads us to classify the real quadratic fields into the sets Jacobsons results shows that and Sliwa confirm that and are the only real quadratic fields in .