Study of Non-Equilibrium Electron Dynamics in Metals

Thermal phenomena, such as heat propagation, lattice melting, and ablation, are the result of energy deposition in metals. A fundamental understanding of the electron dynamics leading to these thermal phenomena would benefit many laser applications, such as laser deposition of thin films and laser processing. In this work, thin metal films were prepared using the resistive heating evaporation technique. High dynamic range autocorrelators were constructed to characterize the different laser systems used in this study. The nonequilibrium electron dynamics in single layer gold films, multi-layer gold-vanadium, and gold-titanium films were studied. The time evolution of the electron temperature was monitored using femtosecond time-resolved thermoreflectivity (ΔR/R) measurements. The validity of the Two-Temperature Model (TTM) in describing ultrafast laser heating processes was checked. The effect of the padding layer on the surface damage threshold was investigated. The experimental results revealed a reduction of the thermoreflectivity signal, ΔRmax, for the multi-layer film that signifies a reduction in the surface electron temperature. Multi-shot damage experiments, in contrast to the thermoreflectivity measurements and the results of Qiu et al., showed no evidence of surface damage in the case of the gold sample, whereas the multi-layer sample experienced an onset of surface damage at the same experimental conditions. The suitability of the Two-Temperature Model (TTM) in describing the transport and relaxation dynamics of hot electrons accurately was verified. A new methodology for the correction of the TTM to account for the internal thermalization of the electron gas and convolution effects was achieved

Using currency demand to estimate the Palestine underground economy: An econometric analysis

The existence of an underground economy may hide the official number of unemployed persons, their share in the labour force, and wages. It also gives rise to the economic and social conditions of individuals, household and countries, which are evaluated in a biased way if one relies on the official statistics. In this paper, we use the currency demand model of Tanzi to estimate the underground economy in Palestine over the period: (2008–2017). Toward that end, a group of econometric techniques of time series data was applied. The main empirical results show that the underground economy reached up to 28.6% in 2010 of the GDP with about USD 2676.227 million. The empirical study results also reveal that the explanatory variables listed in the study model suggested by economic theory and previous research have a significant impact on the dependent one, except the variable ratio of governmental wages and salaries to GDP. However, the money received by the government employees does not contribute to the underground economy.In preparation for this paper, I had to take the help of some respected professors in empirical economics, who deserve my deepest gratitude. As the completion of this paper gave me much pleasure, we would like to express my appreciation for all those who have directly and indirectly helped us in preparing this research paper

Ablative Fractional 10 600 nm Carbon Dioxide Laser Versus Non-ablative Fractional 1540 nm Erbium-Glass Laser in Egyptian Post-acne Scar patients

Introduction: Non-ablative fractional erbium-doped glass 1540 nm and fractional ablative 10600 nm carbon dioxide lasers are regarded as effective modalities for treating acne atrophic scars. In this study, we aimed to compare the effectiveness of fractional CO2 laser and fractional non-ablative 1540 nm erbium doped glass laser in treating post acne atrophic scars in Egyptian patients.Methods: Fifty-eight patients complaining of moderate and severe acne atrophic scars were randomly divided into 2 groups of 29 patients each. Both groups were subjected to 4 treatment sessions with 3 weeks interval and were followed up for 3 months. In group A, enrolled patients received CO2 laser, while in group B, patients were treated with 1540 nm erbium glass fractional laser.Results: Clinical assessment revealed that the mean grades of progress and improvement were higher with fractional 10600 nm CO2 laser but with non-significant difference between both treatments (P = 0.1). The overall patients’ satisfaction with both lasers were not significantly different (P = 0.44).Conclusion: Both fractional ablative CO2 and fractional non-ablative erbium glass lasers are good modalities for treating acne scars with a high efficacy and safety profile and good patient satisfaction. The fractional ablative laser showed higher efficacy while non-ablative laser offered less pain and shorter downtime

User acceptance and adoption of smart homes: A decade long systematic literature review

This survey aims to provide a coherent and bibliometric overview of the theories and constructs employed in smart homes acceptance and adoption literature. To achieve the study aims, we con-ducted a systematic search for every article related to the SH concept, services and applications, user acceptance and adoption, and integrated IoT home appliances and devices, in 10 major library databases, namely, IEEE Digital Library, ACM Digital Library, Association for Information Systems (AIS), Elsevier, Emerald, Taylor and Francis, Wiley InterScience, Springer, Inderscience, and Hindawi. These databases contain literature focusing on smart home adoption using IoT tech-nology. 40 research articles of journal and peer-reviewed conferences were found relating to our research objective, presented and distributed chronologically, by publisher, country, theory and model, key construct, and with full bibliometrics for each article. Additionally, this survey includes a word cloud and a taxonomy of the entire factors used to understand users’ acceptance and adoption of smart homes in different contexts and applications. This study has many ad-vantages in covering the current research gap in the literature and also the researchers identify theoretical and practical research implications, research limitations, and recommendations for improving the acceptance and usage of smart homes literature

Does Spending Matter in Improving Healthcare Across MENA Region

This study addresses the impact of healthcare spending on quality of health. Particularly, it investigates the impact of health budget allocation, health system performance, a nation’s income, and demographic aspects on prompting health quality across the MENA region. The yearly data sample used covers the period 1995–2016. The estimated model is tested using the appropriate GLS random effects method. The findings do not show support for public spending on healthcare to improve healthcare quality across the MENA region. However, higher private spending on healthcare leads to lower infant mortality rates, thus improving healthcare quality. The results also show that the improvement in income per-capita for oil-exporting countries leads to improved quality of healthcare as well as in non-oil-exporting countries, however the marginal benefit is lower for oil-exporting countries, compared to non-oil-exporting countries. This might suggest that oil-exporting countries have already reached a significant floor level of infant mortality rate that cannot be improved. However, non-oil-exporting countries still have potential to reduce the infant mortality rate and improve the quality of healthcare

Correlation Between the Total Small Bowel Length and Anthropometric Measures in Living Humans : Cross-Sectional Study

Open Access via Springer Compact AgreementPeer reviewedPublisher PD

Flash Flood Risk Estimation of Wadi Qena Watershed, Egypt Using GIS Based Morphometric Analysis

Flash flooding is one of the periodic geohazards in the eastern desert of Egypt where many parts of Upper Egypt, Sinai, and Red Sea areas were hit by severe flash floods, for example in 1976, 1982, 1996 and January 2010. The hazard degree for each sub-basin was determined using the approach developed by El-Shamy for assessing susceptibility of sub-basins to flash flooding risk. To identify at-risk sub-basins, two different methods were applied. The first method is based on the relationship between the drainage density and bifurcation ratio, and the second one uses the relationship between drainage frequency and bifurcation ratio. The three morphometric parameters (the bifurcation ratio, drainage density, and stream frequency) were extracted and calculated for each sub-basin of the watershed. Based on the final hazard degree resulting from the two methods, a detailed hazard degree map was extracted for all sub-basins. The results illustrate that there are no sub-basins with low risk of flooding. The sub-basins with the highest hazard degree are concentrated in the middle of the watershed although they have smaller areas compared with the surrounding sub-basins. The sub-basins located at the boundary of the watershed have an intermediate risk of flooding and moderate potential for groundwater recharge. This constructed map can be used as a basic data for assessment of flood mitigation and planning