A metal mandrel was designed for manufacturing the cathodes of high power electron tube ( Tetrode ) used in broadcasting transmitting tubes type TH558 and CQS200.The cathodes were manufactured in the present work from thoriated tungsten wires ( 2? ThO2- W) with different diameters .These cathodes were carbonized in sequences of processes to determine the carbonization parameters (temperature, pressure, time, current and voltage).Then the carbonized cathodes dimension were accurately measured to determine the deviation due to the high temperature distortion effect at about 1800°C .the distorted cathodes due to the carbonization process was treated when it was subjected inside the vacuum chamber and heat treated again .The carbonized cathode distortions as a function of temperature were measured in the range of (1500°C-1800°C).The temperature was determined using an optical pyrometer and also calculated using Stephan's-Boltzmann relation.
This research aims to identify the cognitive distortion of kindergarten children and its relationship to their parenting reinforcement. The researcher used the descriptive approach, being the closest to reaching the study objectives, To measure the relationship between the research variables, the researcher prepared two questionnaire tools for this purpose, the first for measuring "cognitive distortion", And the second is to measure "parental reinforcement", and each tool consisted of (20) items.
After ensuring the validity and reliability of the two research tools and their suitabi
... Show MoreKrawtchouk polynomials (KPs) and their moments are promising techniques for applications of information theory, coding theory, and signal processing. This is due to the special capabilities of KPs in feature extraction and classification processes. The main challenge in existing KPs recurrence algorithms is that of numerical errors, which occur during the computation of the coefficients in large polynomial sizes, particularly when the KP parameter (p) values deviate away from 0.5 to 0 and 1. To this end, this paper proposes a new recurrence relation in order to compute the coefficients of KPs in high orders. In particular, this paper discusses the development of a new algorithm and presents a new mathematical model for computing the
... Show MorePyrolysis of high density polyethylene (HDPE) was carried out in a 750 cm3 stainless steel autoclave reactor, with temperature ranging from 470 to 495° C and reaction times up to 90 minute. The influence of the operating conditions on the component yields was studied. It was found that the optimum cracking condition for HDPE that maximized the oil yield to 70 wt. % was 480°C and 20 minutes. The results show that for higher cracking temperature, and longer reaction times there was higher production of gas and coke. Furthermore, higher temperature increases the aromatics and produce lighter oil with lower viscosity.
Discrete Krawtchouk polynomials are widely utilized in different fields for their remarkable characteristics, specifically, the localization property. Discrete orthogonal moments are utilized as a feature descriptor for images and video frames in computer vision applications. In this paper, we present a new method for computing discrete Krawtchouk polynomial coefficients swiftly and efficiently. The presented method proposes a new initial value that does not tend to be zero as the polynomial size increases. In addition, a combination of the existing recurrence relations is presented which are in the n- and x-directions. The utilized recurrence relations are developed to reduce the computational cost. The proposed method computes app
... Show MoreThe current search aims to identify First: To measure the level of authoritarian personality among the students of the sample as a whole. Second: Measurement of differences in the level of authoritarian personality among students in the middle school according to the following variables 0.Science (literary, scientific) 8. Sex (male - female) Third: the level of control site level among the students of the sample as a whole. Ra'aa: Measurement of differences in the level of the control site among junior students according to the following variables 0.Science (literary, scientific) 8. Sex (male - female) Fifth: Explain the relationship between the authoritarian personality and the locus of control among the students of the research sample.
... Show MoreThe effect of some environment faetor (different temperature and relative humidity) on the biology of the old world- screw worm, were studied under laboratory condition, the result showed that non of the eggs hatched at 15°c and under dried eondition which relative humidity between 20-40%, also result showed that the mature larvae needs one days to become pupa since it leaves the larval died at the temperature ranged between 25-40°C at different humidity rates. While it needs 3 days under lower temperature and different humidity to become pu^, on the other hand the results showed that either low temperature and dried condition or high temperature at different humidity rates cause non of pupa became adult. While low temperature (15-20) °c
... Show MoreIt is known that life is as series of variety of difficult problems that individual looks
forward to overcome so as to achieve adaptation and to reach the desired aims .The transition
of the students from the school stage to the stage of the university is actually regarded a
dramatic change where students face when they enter university life that differs from what
they lived in secondary school.
The executive functions are considered the main element that participate in solving the
problems of high orders , because it involves the mental abilities that assist individual to
think and initiative as well as solving problems .
These functions include operational planning and the activated memory and inhibition of
q
The study aims to examine the classroom activities of the developed English course (Flying High) for the high school first-grade students, identify creative thinking skills appropriate for this grade, and show the extent the classroom activities involve these skills from the female- teachers ‘point of view. The study adopted the descriptive survey method. The study community consists of all (50) English female-teachers who teach high school first grade in Arar city during the academic year (1440 -1441 A.H, the first semester). The study was applied to all respondents. The researcher used a questionnaire as a study tool. The study revealed that the female-teachers reported their disagreement and refusal of the classroom activities in th
... Show MoreThe research deals with a new type of high-performance concrete with improved physical properties, which was prepared by using metal additives minutes (Metakaolin) and by studing their impact on the properties of mortar and concrete high-performance through destructive and non destructive tests. This type of concrete is used broadly in public buildings and in other structures . The research involved a number of experiments such as finding the activity index of burned at a temperature of 750 º C according to the standard ( ASTM C-311/03), as well as casting models for the cubic mortar mixtures and concrete containers at different rates of metakaolin ranging between (5% - 20%) as an added part to the cement mix to get a high- compressive
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