Heat transfer around a flat plate fin integrated with piezoelectric actuator used as oscillated fin in laminar flow has been studied experimentally utilizing thermal image camera. This study is performed
for fixed and oscillated single and triple fins. Different substrate-fin models have been tested, using fins of (35mm and 50mm) height, two sets of triple fins of (3mm and 6mm) spacing and three frequencies
applied to piezoelectric actuator (5, 30 and 50HZ). All tests are carried out for (0.5 m/s and 3m/s) in subsonic open type wind tunnel to evaluate temperature distribution, local and average Nusselt number (Nu) along the fin. It is observed, that the heat transfer enhancement with oscillation is significant compared to without oscillation for low air inlet velocity. Higher thermal performance of triple fins is obtained compared to the single rectangular fin, also triple fins with (height=50mm and fin
spacing=3mm) gives better enhancement as compared to other cases. This work shows that the piezoelectric actuator when mounted on the rectangular fins shows great promise for enhancing the heat transfer rate.
Purpose: Despite the high clinical accuracy of dynamic navigation, inherent sources of error exist. The purpose of this study was to improve the accuracy of dynamic navigated surgical procedures in the edentulous maxilla by identifying the optimal configuration of intra-oral points that results in the lowest possible registration error for direct clinical implementation. Materials and methods: Six different 4-area configurations were tested by 3 operators against positive and negative controls (8-areas and 3-areas, respectively) using a skull model. The two dynamic navigation systems (X-Guide® and NaviDent®) and the two registration methods (bone surface tracing and fiducial markers) produced four registration groups. The accuracy of the
... Show MoreThis research explores the obstacles teachers encounter in executing the smart schools initiative within the framework of Iraq, where educational facilities and digital preparedness are still at an early stage. Although worldwide trends reveal the growing use of smart technologies in education, Iraq has been hindered by systemic barriers, such as archaic curricula, restricted access to technologies, and an unqualified teaching staff. Data were collected using a validated questionnaire on 122 public school teachers working in Baghdad with a descriptive-analytical methodology. The study divided challenges into five areas: infrastructure, teacher preparedness, administrative support, curricular adaptation and cultural resistanc
... Show MorePure Cu (CZTSe) and Ag dopant CZTSe (CAZTSe) thin films with Ag content of 0.1 and 0.2 were fabricated on coring glass substrate at R.T with thickness of 800nm by thermal evaporation method. Comparison between the optical characteristics of pure Cu and Ag alloying thin films was done by measuring and analyzing the absorbance and transmittance spectra in the range of (400-1100)nm. Also, the effect of annealing temperature at 373K and 473K on these characteristics was studied. The results indicated that all films had high absorbance and low transmittance in visible region, and the direct bang gap of films decreases with increasing Ag content and annealing temperature. Optical parameters like extinction coefficientrefractive index, and
... Show MoreObjective(s): The aim of this study is to compare the impact strength of a heat cured denture-base acrylic resin
reinforced with metal wire and glass fibers.
Methodology: Forty five specimens were prepared from pink heat cure acrylic resin. Specimens were grouped into;
group-I (control group) which consists of 15 specimens with no reinforcement, group-II which consists of 15 specimens
reinforced with metal wire, and group-III consists of 15 specimens reinforced with glass fibers. Specimens were tested
by using charpy impact machine.
Results: The result showed that there was a highly significant difference in impact strength value among the testing
groups at (P < 0.001).
Conclusion: The impact str
... Show MoreThe present study aims at identifying the effect of organizational pressure with its aspects (management, work team, nature and conditions of work, external environment) on job performance in all its dimensions (commitment and effort made, capabilities and the rapidity of performance, motivation and job satisfaction, work environment) for the university teacher at the Faculty of Economics, Commercial and Management Sciences at the University of Djelfa, Algeria.
In this research, the descriptive analytical approach is used. Data was collected through the distribution of a questionnaire to a sample that included 130 permanent teachers before being analyzed using the (SPSS) statisti
... Show MoreThe importance of government Expenditure policy in economy come from its role leading to the mitigation and adjustment of fluctuations in macroeconomic variables caused by imbalance between aggregate demand and aggregate supply, It is associated with the efficient management of government Expenditure to reinforcement the relationship between government Expenditure and the overall economic system .
Regarding the Iraqi economy,the increasing in financial rentier after the political change in 2003 has led to finance the budgets Characterized by consumption,The government Expenditure employed to encourage government employment in services jobs, and find different channels for the distribution of
... Show MoreThe dangers of (Israel's) integration with Arab countries in the middle east region will threaten the Arab security structure dimension, which the latter makes the Arab regional system vulnerable for distortion due to its nominal and symbolic value which is far from the Arab self and questioning with its effectiveness in comparing with the real capabilities to Arab countries in achieving the common targets. So, how to assess the different problems that began to hit the structure of the Arab regional system? and how to pledge an allegiance after putting forward what is known as the American Deal of the Century for the administration of former US President Donald Trump for making another step toward normalization with (Israel)?. The reveal
... Show MoreAbstract
The current research aims to identify the effectiveness of concept maps in the academic achievement of the art of elegance and fashion for third vocational students. The current research is a quasi-experimental one. The research sample consisted of (74) female students in Al-Saydiyah secondary school for girls, they were divided into two groups: the experimental group and the control group. The following hypothesis was developed: There are no statistically significant differences at the level (0.05) between the average scores of the students who studied the subject using concept maps and the average scores of the students who studied the subject in the traditional method in the post-achievement test. The
... Show MoreThe study of the " Speech act " in grammatical codes reveals great efforts in the study of the elements of linguistic communication contained in their efforts, and is part of the study of the linguistics of heritage, and the research has been designed to identify the verbal act in the blog of Ibn al-Khabaz (guiding the shine) by studying its sections comprehensively; To the spirit of grammatical discourse as well as the combination of the concept of the semantic act already verbal according to Searle, and its response in the form of indirect verbal acts more than direct acts, as well as the pure formulas of the opinions of the violators in the speech of Ibn al-Khabaz other than the proven verbal formulas Approval and approval, the class
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