Reducing global warming potential (GWP) of refrigerants is needed to the decrease of ozone-depleting of refrigeration systems leakages. Refrigerant R1234yf is now used to substitute R134a inside mobile air conditioning systems. Thermodynamic properties of R1234yf are similar to R134a. Also, it has a very low GWP of 4, compared to 1430 for R134a, making it a proper choice for future automobile refrigerants. The purpose of this research is to represent the main operating and performance differences between R1234yf and R134a. Experimental analysis was carried out on the automotive air conditioning system (AACS) with 3 kW nominal capacity, to test and compare the performance of R134a with R1234yf. Experiments were accomplish
... Show MoreThe research aims to recognize the impact of the training program based on integrating future thinking skills and classroom interaction patterns for mathematics teachers and providing their students with creative solution skills. To achieve the goal of the research, the following hypothesis was formulated: There is no statistically significant difference at the level (0.05) between the mean scores of students of mathematics teachers whose teachers trained according to the proposed training program (the experimental group) and whose teachers were not trained according to the proposed training program (the control group) in Pre-post creative solution skills test. Research sample is consisted of (31) teachers and schools were distribut
... Show MoreAbstract The painful history of slavery has profoundly affected the identities and social interactions of Afro-Caribbean migrants, whose descendants continue to contend with prejudice and socio-economic marginalization. Andrea Levy's semi-autobiographical novel, The Long Song (2010), traces the turbulent history of Jamaica in the nineteenth century through the lens of Miss Kitty, a character based on Levy's great-great-great grandmother, who was born a slave on the plantation Amity in Saint Catherine's parish. The narrative blends the historical with the fictional and depicts various environmental contexts, inscribed meanings, and human exchanges, including the prominence of social situations perceived through race and class tensions ironic
... Show MoreIn recent years, literary studies have witnessed a remarkable shift towards employing digital technologies, particularly artificial intelligence tools, in analyzing literary texts and exploring their linguistic and semantic structures. This trend has provided researchers with new possibilities for understanding texts in quantitative and qualitative ways that transcend traditional methods based solely on critical reading. The current research aims to introduce professors and students of Arabic to artificial intelligence tools that contribute to the analysis of literary texts, focusing on exploring their mechanisms for studying style, meaning, structure, and emotion. It also seeks to highlight the most prominent challenges facing researchers
... Show MoreThis paper is focused on orthogonal function approximation technique FAT-based adaptive backstepping control of a geared DC motor coupled with a rotational mechanical component. It is assumed that all parameters of the actuator are unknown including the torque-current constant (i.e., unknown input coefficient) and hence a control system with three motor control modes is proposed: 1) motor torque control mode, 2) motor current control mode, and 3) motor voltage control mode. The proposed control algorithm is a powerful tool to control a dynamic system with an unknown input coefficient. Each uncertain parameter/term is represented by a linear combination of weighting and orthogonal basis function vectors. Chebyshev polynomial is used
... Show MoreAbstract
The objective of this research is to identify the analysis of the ethics of the administration in the development of the social responsibility of one government organizations, and to achieve the objectives of the research was the use of a questionnaire developed for the purpose of data collection and distribution to the research sample, was chosen as a total sample population (50) individuals were relying on statistical package to do a statistical analysis for this research, user, ANSI (SPSS) simple regression analysis, standard deviation, Pearson correlation coefficient.
Research findings show the role of social responsibility in achieving the university's strategy,
... Show More