University of Jordan

About: University of Jordan is a education organization based out in Amman, Jordan. It is known for research contribution in the topics: Population & Health care. The organization has 7796 authors who have published 13764 publications receiving 213526 citations.

Glass transition activation energy, glass-forming ability and thermal stability of Se90In10−xSnx (x=2, 4, 6 and 8) chalcogenide glasses

Abstract: Differential scanning calorimeter (DSC) has been employed to investigate the glass transition activation energy Et, thermal stability and the glass-forming ability (GFA) of Se90In10−xSnx (x=2, 4, 6 and 8) chalcogenide glasses. From the dependence of the glass transition temperature Tg on the heating rate β, the Et has been calculated on the basis of Moynihan and Kissinger models. Results indicate that Tg and Et attain their minimum values at 6 at% of Sn. Thermal stability has been monitored through the calculation of the temperature difference Tc–Tg, the stability parameter S, the enthalpy released during the crystallization process Hc and the crystallization rate factor Kp. The GFA has been investigated on the basis of Hurby parameter Hr, which is a strong indicator of GFA, and the relaxation time. Results of GFA are in good agreement with the fragility index Fi calculation and indicate that Se90In4Sn6 is the best glass former. The compositional dependence of the above-mentioned parameters was discussed on basis of the topological model of Thorpe and Phillips and the critical composition found to occur at an average coordination number 〈z〉≈2.36, which is thermally most stable.

Extension of an Existing Model for Soil Water Evaporation and Redistribution under High Water Content Conditions

Abstract: Most crop, hydrology, and water quality models require the simulation of evaporation from the soil surface. A model developed by J.T. Ritchie in 1972 provides useful algorithms for estimating soil evaporation, but it does not calculate the soil water redistribution resulting from evaporation. A physically-based model using diffusion theory, described previously by Suleiman and Ritchie in 2003, provides effi cient algorithms for soil water redistribution and soil evaporation. However, the model is appropriate only for second stage drying when the soil in the entire profi le being simulated is below the drained upper limit (θ DUL ) and no more drainage occurs due to gravity. This paper extends the Suleiman–Ritchie model for soil water contents higher than θ DUL where soil evaporation rates are usually higher than second stage drying. New algorithms were developed for these wetter conditions that are functions of soil depth and the wetness of the near-surface soil. New model parameters were calibrated with data measured in laboratory soil column studies. The resulting model was integrated into DSSAT-CSM (Decision Support System for Agrotechnology Transfer Cropping Systems Model). Simulated soil evaporation rates and soil water contents obtained using the Suleiman–Ritchie model with the developed extensions and the previous DSSAT soil evaporation model were compared and evaluated with fi eld measurements of soil water content during several drying cycles for parts of 3 yr in North Central Florida. Computed soil water contents from the model agreed well with the measured soil water contents near the surface, and provided more accurate estimations than the original DSSAT soil evaporation model, especially for the 5-cm surface layer.

Impact of conflict in Syria on Syrian children at the Zaatari refugee camp in Jordan

Abstract: This paper describes a study performed to investigate the impact of the conflict in Syria on Syrian refugee children. The Zaatari refugee camp in Jordan was chosen for this task. Two control (comparison) groups of children were selected: one from the Jordanian Ramtha district, which is just across the border from Syria, and that indirectly feel the consequences of the Syrian conflict, and the other from Amman, the capital of Jordan, which is far away from the border. The study compared the Zaatari, Ramtha and Amman groups in terms of expressed anxiety and depression symptoms. They were also compared with respect to their gender and age. The Zaatari children were more distressed than the others, and the symptom ‘thoughts of ending your life’ was expressed only by this group. The Ramtha group also expressed some distress. The fact that this group indirectly experiences the consequences of violence emphasises the dire circumstances of children inside Syria who are trapped between fighting groups.

Numerical investigations on COVID-19 model through singular and non-singular fractional operators

Abstract: Nowadays, the complete world is suffering from untreated infectious epidemic disease COVID-19 due to coronavirus, which is a very dangerous and deadly viral infection So, the major desire of this task is to propose some new mathematical models for the coronavirus pandemic (COVID-19) outbreak through fractional derivatives The adoption of modified mathematical techniques and some basic explanation in this research field will have a strong effect on progressive society fitness by controlling some diseases The main objective of this work is to investigate the dynamics and numerical approximations for the recommended arbitrary-order coronavirus disease system This system illustrating the probability of spread within a given general population In this work, we considered a system of a novel COVID-19 with the three various arbitrary-order derivative operators: Caputo derivative having the power law, Caputo?Fabrizio derivative having exponential decay law and Atangana?Baleanu-derivative with generalized Mittag?Leffler function The existence and uniqueness of the arbitrary-order system is investigated through fixed-point theory We investigate the numerical solutions of the non-linear arbitrary-order COVID-19 system with three various numerical techniques For study, the impact of arbitrary-order on the behavior of dynamics the numerical simulation is presented for distinct values of the arbitrary power ?