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The rheological properties of coating suspensions containing a blend of clay and CaCO3 as a pigment have been evaluated at 22°C, using a rheometer with shear rates from 0.5 to 100rpm. The state of dispersion of the pigment, the structure viscosity of the suspension as a result of pigment‐pigment or pigment‐binder interactions, and its behaviour by changing the solid content and ionic strength, were limited from the examination of the flow curves. The flow parameters for each suspension were calculated. The results showed that changes in solid content and ionic strength by the addition of divalent simple electrolyte (CaCl2) and pH level have a more profound effect on the flow parameters than that obtained by the addition of monovalent simple electrolyte (NaCl) or polyelectrolyte soluble polymers (CMC) with different degrees of substitution. The type of acid used to adjust the pH of the suspension also has a great influence on the flow parameters.

The purpose of this study is to perform quantum chemical calculations based on the DFT method on four bipyrazoles used as corrosion inhibitors for the plain carbon (“mild”) steel in acid media to determine the relationship between inhibition efficiency and the molecular structure of inhibitors.

Several quantum chemical parameters, such as the charge distribution, energy and distribution of highest occupied molecular orbital and lowest unoccupied molecular orbital, the absolute electronegativity (χ) values and the fraction of electrons (△N) transferring from inhibitors to the steel surface, were calculated and correlated with inhibition efficiencies.

The results showed that the inhibition efficiency of bipyrazole increased with the increasing in EHOMO, and the areas containing N atoms were the most probable sites to donate electrons for adsorbing the inhibitor molecules onto the metal surface.

It is a useful method to investigate the mechanisms of reaction by calculating the structure and electronic parameters, which can be obtained by means of theoretical quantum theory. Thus, the behavior and mechanism of the organic inhibitors can be obtained. Quantum chemical method can also be used to guide the selection and molecular design of inhibitors.

The present work aims to prepare biocomposites blend based on linear low density polyethylene/ starch without using harmful chemicals to improve the adhesion between two phases. Also, the efficiency of essential oils as green plasticizers and natural antimicrobial agents were evaluated.

Barrier properties and biodegradation behavior of linear low density polyethylene/starch (LLDPE/starch) blends plasticized with different essential oils including moringa oleifera and castor oils wereassessed as a comparison with traditional plasticizer such as glycerol. Biodegradation behavior forLLDPE/starch blends was monitored by soil burial test. The composted samples were recovered then washed followed by drying, and weighting samples after 30, 60, and 90 days to assess the change in weight loss. Also, mechanical properties including retention values of tensile strength and elongation at break were measured before and after composting. Furthermore, scanning electron microscope (SEM) was used to evaluate the change in the morphology of the polymeric blends. In addition to, the antimicrobial activity of plasticized LLDPE/starch blends films was evaluated using a standard plate counting technique.

The results illustrate that the water vapor transition rate increases from 2.5 g m⁻² 24 h⁻¹ for LLDPE/5starch to 4.21 g m⁻² 24 h⁻¹ and 4.43 g m⁻² 24 h⁻¹ for castor and moringa oleifera respectively. Also, the retained tensile strength values of all blends decrease gradually with increasing composting period. Unplasticized LLDPE/5starch showed highest tensile strength retention of 91.6% compared to the other blends that were 89.61, 88.49 and 86.91 for the plasticized LLDPE/5starch with glycerol, castor and M. oleifera oils respectively. As well as, the presence of essential oils in LLDPE/ starch blends increase the inhibition growth of escherichia coli, candida albicans and staphylococcus aureus.

The objective of this work is to develop cost-effective and environmentally-friendly methods for preparing biodegradable polymers suitable for packaging applications.

This paper introduces an audio encryption algorithm based on permutation of audio samples using discrete modified Henon map followed by substitution operation with keystream generated from the modified Lorenz-Hyperchaotic system. In this work, the audio file is initially compressed by Fast Walsh Hadamard Transform (FWHT) for removing the residual intelligibility in the transform domain. The resulting file is then encrypted in two phases. In the first phase permutation operation is carried out using modified discrete Henon map to weaken the correlation between adjacent samples. In the second phase it utilizes modified-Lorenz hyperchaotic system for substitution operation to fill the silent periods within the speech conversation. Dynamic keystream generation mechanism is also introduced to enhance the correlation between plaintext and encrypted text. Various quality metrics analysis such as correlation, signal to noise ratio (SNR), differential attacks, spectral entropy, histogram analysis, keyspace and key sensitivity are carried out to evaluate the quality of the proposed algorithm. The simulation results and numerical analyses demonstrate that the proposed algorithm has excellent security performance and robust against various cryptographic attacks.

The purpose of this study is to analyse the magnetic field effect on Fe₃O₄/H₂O Ferrofluid flowing in a sudden expansion tube, which has specific behaviour in terms of rheology, with convex dimple fins. Because the investigation of flow separation is a prominent application in performance, the effect of magnetic field and convex dimple on the thermo-hydraulic performance of sudden expansion tube are examined, in detail.

During the solution of the boundary conditions of the sudden expansion tube, finite volume method was used. Analyses have been conducted considering the single-phase solution, steady-state, incompressible fluid and no-slip condition of the wall under forced convection conditions. In the analyses, it has been assumed that the flow was developing thermally and has been fully developed hydrodynamically.

The present study focuses on exploring the influence of the magnetic field, nanofluid concentration and convex dimple fins on the thermo-hydraulic performance of sudden expansion tube. The results indicate that the strength of the magnetic field, nanofluid concentration and convex dimple fins have a positive effect on the convective heat transfer in the system.

The authors conducted numerical studies, determining through a literature search that no one had yet investigated enhancing heat transfer on a sudden expansion tube using combinations of magnetic fields, nanofluids and convex dimple fins. The results of the numerical analyses provide valuable information about the improvement of heat transfer and system performance in electronic device cooling and heat exchangers.

The purpose of this paper is to investigate the long-run impact of foreign aid and workers’ remittances on Jordanian economic growth using time series data for the period 1970–2014. Following the most recent literature, the author also assess whether economic policy enhances economic growth and whether aid effectiveness is conditional on levels of economic policy.

The author employs unit root tests that allow for endogenously determined structural breaks (Perron, 1997) and properly utilize the autoregressive distributed lag (ARDL) or bounds testing approach to cointegration by applying both the F- and the t-test statistics (Pesaran et al., 2001). The analysis is applied to 12 different models that incorporates the various types and sources of foreign aid.

Empirical results suggest that aid and its various components, and workers’ remittances have had a positive and significant long-run impact on economic growth. Empirical results also show: no evidence supporting the hypothesis that aid is only or more effective in spurring economic growth during periods of “good” macroeconomic policy, i.e., when Jordan has undertaken World Bank Structural Adjustment Programs (SAPs); no robust evidence supporting the World Bank’s claim that SAPs are growth enhancing. Moreover, the author found strong empirical evidence suggesting that exports and human capital are also major determinants of long-run growth in Jordan.

Although Jordan and the region at large have experienced periods of major political instability that may have had a varying impact on the economy, lack of a reliable and lengthy time series measure that accounts for political instability is not available to include in the study.

Using cointegration analysis, our empirical evidence reveals that foreign aid, labor remittances, exports and human capital have had a robust positive long-run impact on economic growth. Hence, the Jordanian government should promote policies that encourage donor countries and agencies to further extend aid to Jordan. Moreover, policies that promote exports and facilitate labor mobility to neighboring countries should also be encouraged and promoted.

Despite receiving a significant amount of foreign aid and labor remittances in the last 50 years, the author found no time series study that tested the long-run impact of these external financing sources on growth in Jordan. This study fills that gap and extends the analysis to test whether macroeconomic policy is growth enhancing and whether aid (and several of its components) are only effective or more effective in promoting growth during periods of “good” macroeconomic policy, i.e., when Jordan has undertaken a World Bank SAP.

The study aims to tackle Egypt's rising electricity consumption due to climate change and population growth, focusing on the building sector, which accounts for up to 60% of the issue, by developing new energy-efficient design guidelines for Egyptian buildings.

This study comprises six key steps. A literature review focuses on energy consumption and efficiency in buildings, monitoring a single-family building in Cairo, using Energy Plus for simulation and verification, performing multi-objective optimization, comparing energy performance between base and controlled cases, and developing a localized version of the Passive House (PH) called Energy Efficiency Design Criteria (EEDC).

The research shows that applying the (EEDC) suggested by this study can decrease energy consumption by up to 58% and decrease cooling consumption by up to 63% in residential buildings in Egypt while providing thermal comfort and reducing greenhouse gas emissions. This can benefit users, alleviate local power grid strain, contribute to Egypt's economy, and serve as a model for other countries with similar climates.

To date, no studies have focused on developing energy-efficient design standards tailored to the Egyptian climate and context using the Passive House Criteria concept. This study contributes to the field by identifying key principles, design details, and goal requirements needed to promote energy-efficient design standards for residential buildings in Egypt.