The ceramic compound Mg1-xSixAl2O4 (x= 0, 0.1, 0.2, 0.3, 0.4) was prepared from nano powder of Al2O3 and MgO doped with Nano powder of SiO2 at different molar ratios. The specimens were prepared by standard chemical solid reaction technique and sintered at 1450 oC. Structure of the specimens was analyzed by using X-ray diffraction (XRD). The X-ray patterns of the specimens showed the formation of pure simple cubic spinel structure MgAl2O4 phase with space group of ̅ . The average grain size and surface topology were studied by atomic force microscopy. The results showed that the average grain size was about 73-90 nm. The DC electrical properties of the specimen were measured. The apparent density was found to increase and the porosity and water absorption were found to decrease with increase of Si addition. Mechanical properties were characterized by Vicker’s micro hardness and Brazilian fracture test to measure the fracture toughness of the samples. The micro hardness decreased with Si addition increase. Fracture toughness increased with the increase in Si addition.
The irony pushes us to inquire about what is in the text of contradiction, irony, suspense, and other acts of paradox, as well as a departure from what is logical, or familiar, that attracts the attention of the addressee, and this is what drives us to introspect the text and interrogate it in order to get to know the intended product of the text or its real or metaphorical intent. On the other hand, the irony is more in the literary text than in the scientific texts. Therefore, critics add the word literature to it in their definition.
As it is represented by the paradox, we will seek to study the paradox of the title and the problematic that it may pose as the beginning of the text, and i
... Show MoreThe nuclear structure included the matter, proton and neutron densities of the ground state, the nuclear root-mean-square (rms) radii and elastic form factors of one neutron 23O and 24F halo nuclei have been studied by the two body model of within the harmonic oscillator (HO) and Woods-Saxon (WS) radial wave functions. The calculated results show that the two body model within the HO and WS radial wave functions succeed in reproducing neutron halo in these exotic nuclei. Moreover, the Glauber model at high energy has been used to calculated the rms radii and reaction cross section of these nuclei.
Fear, harvesting, hunting cooperation, and antipredator behavior are all important subjects in ecology. As a result, a modified Leslie-Gower prey-predator model containing these biological aspects is mathematically constructed, when the predation processes are described using the Beddington-DeAngelis type of functional response. The solution's positivity and boundedness are studied. The qualitative characteristics of the model are explored, including stability, persistence, and bifurcation analysis. To verify the gained theoretical findings and comprehend the consequences of modifying the system's parameters on their dynamical behavior, a detailed numerical investigation is carried out using MATLAB and Mathematica. It is discovered that the
... Show MoreBaghdad Lake Touristic is suffering from a lake of tourism and entertainment services
efficiency provided to their visitors , knowing that this type of services as they are the basics
to achieve economic and socialist development because of their indicators where their goal is
to serve human in city as they represent lungs which population breathe within .
The Parks are resorted as human usually in search of quiet and funny places , away from
the noise of the city and its complex , as well as they give the city a beauty manifestations ,
that give happiness.
The study reached that there is deficiencies in service present, inability to provide
services and inadequate for the population and bad distribution. So the s
The neutron, proton, and matter densities of the ground state of the proton-rich 23Al and 27P exotic nuclei were analyzed using the binary cluster model (BCM). Two density parameterizations were used in BCM calculations namely; Gaussian (GS) and harmonic oscillator (HO) parameterizations. According to the calculated results, it found that the BCM gives a good description of the nuclear structure for above proton-rich exotic nuclei. The elastic form factors of the unstable 23Al and 27P exotic nuclei and those of their stable isotopes 27Al and 31P are studied by the plane-wave Born approximation. The main difference between the elastic form factors of unstable nuclei and the
... Show MoreThe present study was conducted to determine the optimum conditions required for lipase enzyme activity extracted from germinated sunflower seeds, including temperature, pH, agitation, time of incubation, enzyme concentration, substrate type, and concentrations of mineral salts and EDTA. Optimum pH, temperature and time of incubation required for lipase stability were also determined. The results showede optimum lipase activity (3.251U/ml) wasund at 30 ÌŠC and pH 7 after 20 minutes of incubation when using 1 ml lipase enzyme with 0.02 ml of CaCl2 (10 mM) at 100 rpm of agitation and in the presence of olive oil as the substrate for enzyme reaction. EDTA appeared to have inhibitory effects, while Ca+2 and Mg+2 have stimulatory effec
... Show MoreOur research subject (environmental impact in the cultural output of the civilizations of ancient East) the environmental impact on human civilization and how her and adapted to serve in various cultural aspects especially in ancient cultures whether punches or sculptures and other addresses as well as tracing precious stones and raw materials. It was the environment of the civilizations of Mesopotamia and Egypt and another effective impact in drawing ancient history through human interaction and responsiveness. The Iraqi environment was marked by poverty and cruelty on the one hand and on the other cultural elements contributed to the civilization in General and research dealing with technical and product sourcing raw materi
... Show Moreان من اهم القضايا التي تثيرها المعرفة البشرية في تجلياتها، وتعبيراتها المفاهيمية، تكمن في مدى تأصلها وانتمائها الى البنى والتشكيلات الموضوعية (في مستوياتها التاريخية) التي تسعى لتفسيرها وادراكها ومضاهاتها. فالينبوع الذي يغرف منه الفكر مادته هو الكيان الاجتماعي المتموضع خارج الوعي والايدولوجيا.
ان قدرة الوعي على ادراك الواقع الموضوعي بخصائصه العامة يشكل الشرط الضروري لاكتساب الوعي ل
... Show MoreThe study aimed to measure the phsycological tolerance and self-efficacy among the students of Baghdad university and knon the significant differences in psychological tolerance and self-efficacy according to the variables (Gender-Specialization)and the interaction between themas well as the study aimed to identify the strength and direction of the relationship between psychological tolerance and self-efficacy of the study sampleincluded asample of the current study(370) students from grades four ,the researcher used the measure of psychological tolerance and self-efficacy prepared by the researcher ,and the results showed that college students Generally have adegree of psychological tolerance and that there are statistically sig
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