The varied thermal conductivity (insulation) of silica aerogel with heating for different pH has been investigated, it has been depended on ambient pressure drying method in the preparing silica aerogel samples, also six different pH of samples (1, 2, 3, 7, 8 and 9) were treated under five degree of heating with (50,100,150,200 and 250) ᴼC. This technique is important to test the carry-outs hydrophobic silica to temperature without high-quality material changes in the basic characteristics. The hot-wire technique is used in this work to examine the thermal conductivity, Fourier Transform Infrared Spectroscopy (FTIR) depended to characterize the bonds and their artificial by heating. Results show that the samples affected by heating through decreasing the density leading to obtaining more insulation metal, moreover varied pH is an important role in thermal conductivity. The average thermal conductivity of all aerogel samples in this work is (0.01- 0.0061 mW m-10 C-1) this means that it is still below thermal conductivity for air equals to (0.02257) mW m-10 C-1 . Meanwhile, we concluded that the insulation property of silica aerogel is affected by heat treatment and gives it more thermal insulation property.
The study aims to identify the extent the academics in colleges of applied sciences are familiar with the themes of the national strategy of education 2040 in the Sultanate of Oman. The researchers used the descriptive approach, as well as they adopted a questionnaire with five dimensions as a tool for data collection, which was applied to (120) academics. The results showed that the academics of the applied colleges' familiarity with the National Strategy for Education 2040 in the Sultanate of Oman is average. The study also found that there were no statistically significant differences in the academics estimates of the extent of the Colleges of Applied Sciences academics’ familiarity with the themes of the National Education 2040 Str
... Show MoreThis research aimes to expose the levels of geometrical thinking among the students of mathematic department in Basic Education College at AL-Mustansiriyah University throughout their respondes on the test of geometrical thinking which consists (50) multi- choice items distributed on the first four levels of Van Hiele ( recognition – analysis – ordering – deduction ).
The validity and the reliability of the test have been investigated. Besides, the difficulty and its discrimination have been measured. The activity of the wrong variables has been measured.
The test has been applied on (180) male and female students of the first, second and third grades.
... Show MoreThis study aimed to identify the extent of teachers' application of professional standards from the point of view of supervisors and detecting differences in the means of their estimates that may be attributed to the variables of the study (sex, number of years of service, educational qualification).The study adopted a descriptive approach. In order to achieve the aims of the study, a questionnaire including four areas, namely: (professional features, academic knowledge and pedagogy, teaching and learning, and professional development) was constructed.
The questionnaire was applied to a population which consisted of 60 supervisors of all school subjects in the Directorates of Education in
... 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 .
The temperature control process of electric heating furnace (EHF) systems is a quite difficult and changeable task owing to non-linearity, time delay, time-varying parameters, and the harsh environment of the furnace. In this paper, a robust temperature control scheme for an EHF system is developed using an adaptive active disturbance rejection control (AADRC) technique with a continuous sliding-mode based component. First, a comprehensive dynamic model is established by using convection laws, in which the EHF systems can be characterized as an uncertain second order system. Second, an adaptive extended state observer (AESO) is utilized to estimate the states of the EHF system and total disturbances, in which the observer gains are updated
... Show MoreThis paper discusses the method for determining the permeability values of Tertiary Reservoir in Ajeel field (Jeribe, dhiban, Euphrates) units and this study is very important to determine the permeability values that it is needed to detect the economic value of oil in Tertiary Formation. This study based on core data from nine wells and log data from twelve wells. The wells are AJ-1, AJ-4, AJ-6, AJ-7, AJ-10, AJ-12, AJ-13, AJ-14, AJ-15, AJ-22, AJ-25, and AJ-54, but we have chosen three wells (AJ4, AJ6, and AJ10) to study in this paper. Three methods are used for this work and this study indicates that one of the best way of obtaining permeability is the Neural network method because the values of permeability obtained be
... Show MoreMetaphor is one of the most important linguistic phenomena of the artistic text, as it is the expression of the author’s emotions and evaluations, the result of a deep inner transformation of the semantic words and visual means of reflecting the national culture of each people. This paper examines the concept of linguistic metaphors and analyzes its types in the Russian and Arabic linguistics, provides a comparative analysis of metaphors in Russian and Arabic — all this allows to conclude that metaphorization is characteris- tic of different parts of speech. In the Russian language stylistic differentiation of the metaphors expressed more than in Arabic, so translation of many “sty- listic” metaphors from Russian into Arabic due to
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Man was closely associated with nature in its various forms, as it represented the incubator for him in all areas of his life, so writers often made it a material for their literature and a fertile ground for their productions, so it appeared in its various forms and man’s need for it, its good and its bad in literature throughout history, and the Arabs are like Other nations, since the pre-Islamic era, nature was an important outlet and a refuge for poets in the production and creativity of literature and to this day, and when we talk about a poet from the Fatimid state, we find that nature - especially spring and its flowers - in that period took its take from literature and represented a phenomenon for many Among the
... Show MoreWe studied, in this paper, the semiotics of the visual image of women in the discourse of empowerment, through three models of advertising images expressing the particularities of the Saudi Arabian environment.
We aim to know how the mark operates and how it is interpreted, as a semantic process in which the meaning ranges from description to interpretation, and we studied two hypotheses:
-The advertising image is a structure in which the mark corresponds to the reality and the discourse to the context.
-The significance is not found in the visual sign or in the textual sign of the advertising image, but in the creative event that opens up to the social, cultural, and psychological context, and creates a field of dia
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