Assessment of the Recycled Concrete Aggregates Structural Suitability for Road Construction

In most aspects of modem life, there is a consensus among practitioners and decision makers of the importance of preserving the environment, and to find alternatives to the scarce natural materials. This can be accomplished by better utilization of the natural materials and/or recycling or reclaiming their waste, specially, if they are of finite resources. The recycled material could be an attractive alternative (both environmentally and economically) if its characteristics are proven to be close to those of the natural material. Utilizing recycled mineral aggregates in the construction field in general and in highway pavement in specific is somehow governed by its ability to meet its intended function as carrying component within the structure. In the area of pavement construction, the suitability of the recycled aggregates is primarily judged by its ability to carry the high traffic loads effectively. The primary objective of this thesis is to study the suitability of using the Recycled Concrete Aggregates (RCA) for pavement construction or rehabilitation. The RCA is intended to replace the virgin material in one of the pavement layers, namely the subabse. The general characteristics of the RCA material (such as the grade distribution) are compared against the subbase material specifications. A testing model is built to quantify the RCA-layered pavement performance under various load levels, and to comparatively assess its behavior against the virgin mineral aggregates. The model dimensions are set large enough to replicate the pavement structures in reality to ensure accurate analysis. Several experimental settings are considered to account for the possible variability in the pavement loads (generated by the various vehicle types), material gradation, composition and thickness. The performance of the RCA material is captured through the resulting load-deflection relationships of the various settings. The results of these experiments indicated the good potential of the RCA as a subbase material. The resulting load-deflection relationships of both the RCA- and virgin-materials indicated the superiority of the RCA-material as a subbase material. In general the deflection results of the experiments indicated that the pavement deflection under load is generally lesser with the RCA material

EFFECTS OF EXERCISE AND PHARMACOLOGICAL INTERVENTION ON ELECTROMECHANICAL FUNCTION OF THE HEART IN THE GOTO-KAKIZAKI TYPE 2 DIABETIC RAT

Type 2 diabetes mellitus accounts for more than 90% of cases of diabetes mellitus. Cardiovascular diseases are the major causes of morbidity and mortality in diabetic patients. A variety of diastolic and systolic dysfunctions have been reported. The severity of the abnormalities depends on the patients’ age and diabetes duration. The aim of the study was to investigate the age-dependent, exercise and pharmacological intervention on electromechanical function of the heart in the Goto-Kakizaki (GK) type 2 diabetic rat. mRNA expression was assessed in ventricular muscle with real-time RTPCR. Ventricular myocytes shortening, intracellular Ca2+ transport and L-type Ca2+ current were measured with video edge detection, fluorescence photometry and whole cell patch clamp techniques, respectively. In vivo biotelemetry was used to measure the electrocardiogram. In young GK (8-10 weeks) rat, mRNA expression of Atp1a3, Cacna1h, Scn1b and Hcn2 were upregulated and Slc9a1, Hcn4, Kcna2/4 and Kcnj2 were downregulated. Amplitude of ventricular myocyte shortening and intracellular Ca2+ transient were unaltered, time to peak shortening was prolonged and time to half decay of the Ca2+ transient was shortened in GK myocytes. Physical exercise is well established as a valuable form of non-pharmacological therapy. Experiments were performed in GK and control (10-11 months) following 2-3 months of treadmill exercise training. Expression of mRNA encoding Tpm2, Gja4, Atp1b1, Cacna1g, Cacnb2, Hcn2, Kcna3 and Kcne1 were upregulated and Gja1, Kcnj2 and Kcnk3 were downregulated in hearts of sedentary GK rats compared to sedentary controls. Gja1, Cav3 and Kcnk3 were upregulated and Hcn2 was down-regulated in hearts of exercise vii trained GK compared to sedentary GK controls. Amplitude of ventricular myocyte shortening, Ca2+ transients and L-type Ca2+ current were not significantly altered. The effects of the anti-diabetic drug Pioglitazone on ventricular myocyte shortening and Ca2+ transport in addition to electrocardiogram were also investigated. Pioglitazone (0.1-10) μM reduced the amplitude of shortening in ventricular myocytes from GK and control rats. Pioglitazone reduced the amplitude of the Ca2+ transient and modest reductions in L-type Ca2+ current in GK and control myocytes. Heart rate in GK rats was reduced. Although Pioglitazone reduced blood glucose in GK rats it had little effect on heart electrocardiogram

AN EVALUATION OF THE SCHOOL-BASED MANAGEMENT PRACTICES IN THE NEW SCHOOL MODEL: A STUDY ON AL AIN SCHOOLS

In 2005, the government of Abu Dhabi started a reform initiative by establishing the Abu Dhabi Education Council (ADEC). ADEC became responsible for efforts to improve the performance of schools and increase students’ achievement in the emirate. One way to do this was by creating the New School Model (NSM). Part of the NSM reform was a shift from the centralized system of managing the schools into a decentralized system that delegates and sometimes devolves decision-making authority to schools themselves. The purpose of this study is to investigate the degree to which School-Based Management (SBM) has been practiced in the New School Model (NSM) schools in Al Ain. The other purpose is to investigate the influence of staff position on the practices of the SBM. The third purpose is to identify the main areas of SBM practices that need improvement based on the perceptions of the participants. A descriptive quantitative research method in the form of a questionnaire was utilized to obtain the perceptions of 351 school staff. The conceptual framework for the SBM practices that guided this study was built from a synthesis of literature related to SBM and the features of NSM. The framework identified six critical areas of SBM practices: (a) effective school leadership, (b) budget allocation, (c) management strategies, (d) staff development, (e) curriculum and instruction, and (f) resources. ADEC grants authority in the areas of management strategies, staff development, curriculum and instruction, and resources. The areas of effective leadership and budget allocation have no or little authority. The results indicate that participation of school staff in SBM practices in areas where staff has more authority was greater than their participation in areas with no or little authority. In addition, the staff desire to participate in decision-making was strong and compatible with their actual participation in both areas. Moreover, the staff desire vii and actual participation was stronger in the areas that have direct relations to teaching than to the administrative tasks. The variable of position played a significant role in determining staff perceptions on practices in the areas of curriculum and instruction, management strategies, and resources. Finally, the study found that all areas of SBM need improvement, except for preparing school development plan, which has acceptable practice

INTEGRATING KANO MODEL WITH DATA MINING TECHNIQUES TO ENHANCE CUSTOMER SATISFACTION

The business world is becoming more competitive from time to time; therefore, businesses are forced to improve their strategies in every single aspect. So, determining the elements that contribute to the clients\u27 contentment is one of the critical needs of businesses to develop successful products in the market. The Kano model is one of the models that help determine which features must be included in a product or service to improve customer satisfaction. The model focuses on highlighting the most relevant attributes of a product or service along with customers’ estimation of how these attributes can be used to predict satisfaction with specific services or products. This research aims at developing a method to integrate the Kano model and data mining approaches to select relevant attributes that drive customer satisfaction, with a specific focus on higher education. The significant contribution of this research is to improve the quality of United Arab Emirates University academic support and development services provided to their students by solving the problem of selecting features that are not methodically correlated to customer satisfaction, which could reduce the risk of investing in features that could ultimately be irrelevant to enhancing customer satisfaction. Questionnaire data were collected from 646 students from United Arab Emirates University. The experiment suggests that Extreme Gradient Boosting Regression can produce the best results for this kind of problem. Based on the integration of the Kano model and the feature selection method, the number of features used to predict customer satisfaction is minimized to four features. It was found that either Chi-Square or Analysis of Variance (ANOVA) features selection model’s integration with the Kano model giving higher values of Pearson correlation coefficient and R2. Moreover, the prediction was made using union features between the Kano model\u27s most important features and the most frequent features among 8 clusters. It shows high-performance results

The Most Important Effective Leadership Characteristics of School Principals in Terms of their Significance and Implementation from Perspective of AL-Ain Education Office Teachers

This study aims to investigate about the school principal’s leadership characteristics in terms of their significance and implementation from the perspective Al-Ain schools teachers. Hence, the study employed the quantitative method to collect data about the principals descriptors reviewed in the previous studies. The sample consists of 500 teachers; 200 males and 300 females randomly selected from each school. The study investigated the significance of the principal’s descriptors as well as their significance and to what extent they are implemented by Principals. The study found out that the most significant descriptors of the principals are: keeping promises and punctuality, achieving targets and vision; encouraging teachers to try new methods in classroom, treating others with respect and appreciation, confidence in others capabilities; Following up others commitment of work standards, the leader’s positive attitude towards people from diverse cultures. The study also found that the school principal’s descriptors in terms of their significance and implementation were different according to the gender in favor of females who play more effective roles than males, in terms of the significance of the descriptors, the inspiration role of principals of the shared vision. Finally, there is statistical significance has been found between the effective the school principals descriptors in terms of their implementation and the nationality, in terms of implementation in favor of the UAE Nationals, but the open mind characteristics in favor of expatriates

Photocatalytic Hydrogen Generation from Seawater using High Performance Polymeric Materials

Recently, there has been renewed interest in the use of solar energy as a resource to meet the world’s energy needs in an environmentally sustainable way. Hence, our research focuses on the generation of hydrogen from non-fresh water using the sun as an energy source. The research aims to characterize, assess, and developed new research-grade materials and commercial photocatalysts that can achieve sunlight-driven unassisted photo-splitting of water. In this work, novel conjugated polymer nanoparticles were developed and characterized. The nanoparticles are composed of a donor-acceptor system where two acceptors (A1 and A2) were developed and tested, and different ratios of each donor-acceptor system were assessed. The use of platinum or molybdenum as co-catalysts was explored. Hydrogen evolution reactions with ascorbic acid as sacrificial reagent was performed using these materials and their performance was assessed. The results show that the first system consisting of acceptor A1 and the donor (A1/D) produces more hydrogen than the (A2/D) system. Furthermore, the best ratio of donor to acceptor was determined to be 10:90 for the (A1/D) system. The use of platinum as a co-catalyst was shown to result in a better performance in terms of hydrogen production compared to the use of molybdenum. Furthermore, the results show that the use of nanoparticles suspended in solution results in a higher hydrogen evolution rate compared to the use of films. Hydrogen production of 2018 micromole per hour of catalyst was achieved using the A1/D nanoparticle system with platinum, which represents the best result as initial findings. For future steps, optimization of the reaction will take place to generate more hydrogen