Re-examination of price level differentials using economic freedom index

Findings reported in this paper provide improved explanation as to what factors are correlated with price levels across a large sample of 152 countries. The results are obtained from using a new set of variables called economic freedom indices, covering 19 years. Prior studies used income, trade openness, and productivity, which led to results with much less explanatory power compared to findings reported in this paper. We apply advanced panel data econometrics to obtain robust estimates of parameters, which, in our view, led to results with substantially high coefficient of variations close to 90%. The findings show that all the nine dimensions of economic freedom used in this study significantly account for the variations in national price levels

The Effect of Education Decentralization on School Leadership in the Vocational Schools: A Comparative Study between the German and the Egyptian Practice

Gershberg (1999) defines education decentralization as the transfer of some of the political, administrative, and/or financial authorities and responsibilities from the central government to the local governments, local units or the schools themselves. In this qualitative study the effect of education decentralization on vocational school leadership is explored. Through conducting structural interviews with 30 school principals in Germany and Egypt, the study was able to reach at three main conclusions. 1- Political decentralization encourages the adoption of participatory leadership by involving the stakeholders in the decision-making process and allowing the schools to set their goals and objectives discretionally. 2- Administrative decentralization encourages the adoption of shared instructional leadership by devolving authorities of teacher selection, evaluation, training and team-building to the schools. And 3- financial decentralization encourages the adoption of entrepreneurial leadership by encouraging the schools to raise funds and deploy the available resources discretionally

Influence of Quasiperiodic Gravitational Modulation on Convective Instability of Liquid-Liquid Polymerization Front

The influence of quasiperiodic gravitational modulation on convective instability of polymerization front with liquid monomer and liquid polymer is studied. The model includes the heat equation, the concentration equation, and the Navier-Stokes equations under the Boussinesq approximation. The linear stability analysis of the problem is carried out and the interface problem is derived. Using numerical simulations, the convective instability threshold is determined and the boundary of the convective instability is obtained for different amplitudes and frequencies ratio

Effect of planting methods of flax on garlic yield under different intercropping patterns

The purpose of this experiment was to investigate yield, yield components and economic evaluation of flax (Sakha 5) and garlic (Sids 40) under various planting methods and intercropping patterns. The experimental design was a split-plot design with four replicates. The main-plots were assigned to the three cultivating methods and the sub-plots were allocated to the four intercropping patterns. The results indicated that drilling as planting method achieved the highest values for most studied characters in both seasons for flax and garlic, except for number of cloves/plant and plant height in garlic. Intercropping system with low garlic density (100% flax + 12.5% garlic) produced the maximum values for stem diameter, straw yield, number of capsules and seed/plant, seed index and seed yield for flax and number of leaves and cloves/plant, head diameter and weight for garlic in both seasons. The highest bulb yield of garlic was achieved with intercropping 100% flax + 37.5% garlic in both seasons. It can be concluded that the most economic returns for both crops were obtained from drilling as planting method with intercropping pattern 100% flax + 37.5% garlic under the environmental conditions of North Delta of Egypt. Keywords: Intercropping, Land equivalent ratio (LER), Aggressivity (Ag), Relative crowding coefficient (RCC), economic evaluatio

Task Scheduling Approach in Cloud Computing Environment Using Hybrid Differential Evolution

Task scheduling is one of the most significant challenges in the cloud computing environment and has attracted the attention of various researchers over the last decades, in order to achieve cost-effective execution and improve resource utilization. The challenge of task scheduling is categorized as a nondeterministic polynomial time (NP)-hard problem, which cannot be tackled with the classical methods, due to their inability to find a near-optimal solution within a reasonable time. Therefore, metaheuristic algorithms have recently been employed to overcome this problem, but these algorithms still suffer from falling into a local minima and from a low convergence speed. Therefore, in this study, a new task scheduler, known as hybrid differential evolution (HDE), is presented as a solution to the challenge of task scheduling in the cloud computing environment. This scheduler is based on two proposed enhancements to the traditional differential evolution. The first improvement is based on improving the scaling factor, to include numerical values generated dynamically and based on the current iteration, in order to improve both the exploration and exploitation operators; the second improvement is intended to improve the exploitation operator of the classical DE, in order to achieve better results in fewer iterations. Multiple tests utilizing randomly generated datasets and the CloudSim simulator were conducted, to demonstrate the efficacy of HDE. In addition, HDE was compared to a variety of heuristic and metaheuristic algorithms, including the slime mold algorithm (SMA), equilibrium optimizer (EO), sine cosine algorithm (SCA), whale optimization algorithm (WOA), grey wolf optimizer (GWO), classical DE, first come first served (FCFS), round robin (RR) algorithm, and shortest job first (SJF) scheduler. During trials, makespan and total execution time values were acquired for various task sizes, ranging from 100 to 3000. Compared to the other metaheuristic and heuristic algorithms considered, the results of the studies indicated that HDE generated superior outcomes. Consequently, HDE was found to be the most efficient metaheuristic scheduling algorithm among the numerous methods researched

Flexural, shear, and mechanical behaviour of self-consolidating-rubberized concrete with/without steel fibres

This research program focuses on investigating the applicability of using crumb rubber (CR) as a replacement for fine aggregate in developing a novel eco-friendly concrete type suitable for structural applications, especially when self-consolidating concrete (SCC) is used. Four extensive experimental studies have been carried out on both small- and large-scale concrete specimens to accomplish the research objective. The first and second studies aimed to optimize a number of successful self-consolidating rubberized concrete (SCRC) and steel fibre SCRC (SFSCRC) mixtures with maximized percentages of CR and minimized reduction in the stability and strength. The first parametric study included 27 SCRC mixtures developed with different binder contents (500-550 kg/m³), supplementary cementing materials (SCMs) (metakaolin (MK), fly ash (FA), and ground granulated blast-furnace slag (GGBS)), coarse aggregate sizes (10-20 mm), and entrained air admixture. The second parametric study included 19 SFSCRC mixtures developed with different binder content (550–600 kg/m³), steel fibre (SF) volume fractions (0.35% and 0.5%), and lengths of SFs (35 and 60 mm). In this study (study 2), another three vibrated rubberized concrete (VRC) and four steel fibre VRC (SFVRC) mixtures were developed for comparison. In both study 1 and 2, the fresh and mechanical properties of the developed mixtures were evaluated using small-scale specimens. The fresh properties included flowability, passing ability, high-range water-reducer admixture (HRWRA) demand, coarse aggregate segregation, and CR distribution. On the other hand, the evaluation of mechanical properties in both study 1 and 2 included compressive strength, splitting tensile strength (STS), flexural strength (FS), modulus of elasticity, impact resistance, ultrasonic pulse velocity, and acoustic emission measurements. The third and fourth studies evaluated the structural performance (flexural and shear) of large-scale reinforced concrete beams made with SCRC, VRC, SFSCRC, and SFVRC. In these studies, a total of 36 optimized mixtures from study 1 and 2 were selected to cast 36 large-scale reinforced concrete beams to be tested in flexure and shear (24 beams in flexure and 12 beams in shear). The performance of some design codes and empirical equations in predicting the first cracking moment, flexural, and shear capacity of the tested beams was also evaluated in study 3 and 4. The results showed that using CR in SCRC helped to develop mixtures with improved impact resistance, acoustic absorption capacity, and lower self-weight, but their stability, fresh, and mechanical properties were decreased. However, using higher binder content, different SCMs, and entrained air in SCRC improved their fresh properties and allowed high percentages of CR to be used, successfully. Moreover, MK was found to be the most effective SCMs that could obviously improve the stability and strength of SCRC. Although using SFs in SCRC mixtures negatively affected the fresh properties of the mixtures, they proved to have a significant enhancement on the mixtures’ strengths, especially STS, FS, and impact resistance. Since the challenge to optimize mixtures with high flowability and passing ability was not a factor in developing vibrated mixtures, it was possible to develop SFVRC mixtures with higher percentage of CR and SFs. This high combination of CR and SFs provides a new concrete composite with further improvement in ductility, toughness, impact resistance, and with further reduction in self-weight. The results of the flexural testing conducted in study 3 indicated that increasing the CR appeared to narrow crack widths and improve deformability of SCRC and VRC beams at given load. The safe use of CR in structural applications was found to be 15%. Further increase in the CR content showed a significant reduction in the first cracking moment and ultimate flexural capacity of the tested beams, while the ductility and toughness did not show a confirmed effect for the higher percentages of CR. On the other hand, in SFVRC, the addition of 1% SFs (35 and 60 mm) helped to extend the possible safe content of CR to 35%, achieving successfully semi-lightweight concrete beams with a sufficient capacity, ductility, and toughness for multiple structural applications. In shear testing conducted in study 4, using CR in SCRC and VRC beams showed a reduction in their shear capacity, post-diagonal cracking resistance, and energy absorption. These reductions could be alleviated by inclusion of SFs. The composite effect of CR and SFs also helped to narrow the developed cracks and change the failure mode from a brittle shear failure to a ductile flexural failure, particularly for SFs volume of 1%. The comparisons between the predictions and the experimental results (obtained from study 3 and 4) indicated that most of the proposed equations can satisfactorily estimate the flexural and shear capacity, but the first cracking moment was overestimated