The equilibrium adsorption of diazo dye C.I. Acid Red 97 (AR97) from aqueous solutions onto Yemen natural clay has been studied as a function of temperature and particle size range. The equilibrium data were correlated using Langmuir, Fruendlich, Temkin, Redlich-Peterson, and Sips isotherm models. Thermodynamic parameters such as standard enthalpy (?Hº), standard entropy (?Sº) and standard Gibbs free energy (?Gº) were calculated. It was found that the adsorption capacity of clay for AR97 decreases with increasing temperature and particle size range. The results show that Fruendlich and Sips isotherm models best fit the experimental data over the whole concentration range. The maximum adsorption capacity for Yemen natural clay was 196.7 (mg.g-1 ). The value of ?Hº was -20.5 (kJ.g-mol-1) indicating that the adsorption of AR79 onto Yemen natural clay is characterized by physical adsorption. ?Gº values obtained were all negatives indicating a spontaneous adsorption process.

In the supramolecular chemistry world, Polyoxometalates (POMs) are considered as a new family of inorganic molecular containers, construct itself by self-assembly reaction from very small units, to form a cluster with unique structural and properties. three structures reported in this paper - differ in their unit cell parameters and also differ from the well-known - as the result of reaction of the Na11H[H(2- x)Bi2W20O70(HWO3)x]·46H2O (x=1.4) with Ca ion at different pH conditions. These structures are [Ca(H2O)7]2[Na(H2O)2]2[HBi2W20O70(HWO3)].14H2O(1), H2[NH4]10[HBi2W20O70(HWO3)] (2), and [NH4]6[Na(H2O)4]2[Ca(H2O)4]2[W12O42].2H2O (3). The last one is bismuth-free and it is formed through reassembly of the precursor. Full structural characterization was made by multiple testing techniques such as single-crystal X-ray diffraction, UV-visible spectroscopy, FT-IR, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). The single-crystal X-ray diffraction results for the three compounds are as follows:(1), Triclinic, space group P-1, while (2) and (3) crystallize in monoclinic space groups C2/m and P21/n respectively.

In this study, the geometry optimizations, orbital energies (HOMO-LUMO) and relative stabilities of methylene cyclopentane and 1-methylcyclopentene were investigated by DFT calculations. 1-methylcyclopentene was found to be more stable than methylene cyclopentane isomer with enthalpy value H=18.518 kJ/mol. Also, the effect of substituents X (F, OH, CH3, NH2, CN, NO2, CHO and CF3) also studied on the relative stabilities of these two tautomers. The results showed that the stability of both isomers is increased by all substitutes. Gibbs free energy calculations have been used to find the effect of substituents X on the system.

The need for prediction and reference updating in feedback control of a wet granulation process is addressed. The granulation process is often modeled as a multi-input multi-output (MIMO) linear model with dead-time. Industrial implementation of granulation process poses strict constraints on the process inputs & outputs. The presence of dead-time and the physical necessity of the input-output constraints are the key challenges of the wet granulation control. These challenges motivated the use of model predictive control (MPC) for such processes. In this work, a Smith predictor-based proportional-integral (PI) controller is designed for the dead-time compensation. Accompanied with the reference updating method to handle the physical constraints. The regulation and reference tracking control problems are assessed via closed-loop simulations of the wet granulation model. The ability of the proposed control approach of dead-time compensation and coping with input/output constraints is rigorously proved. The current approach is compared to MPC of a similar granulation process and found superior in terms of output stability, performance and reference tracking.

The most important challenge in a natural gas liquefaction plant is to improve the plant energy efficiency. A process topology should be implemented, which results in a considerable reduction of energy consumption as the natural gas liquefaction process consumes a large amount of energy. In particular, system design focusing on configuring cold part cycle is an attractive option. In this study, various energy recovery-oriented process configurations and the potential improvements of energy savings for small- & midscale liquefied natural gas plants were proposed and compared with almost exclusively commercial trademarks processes. These improved simulation based investigations were validated under the variation in feed gas pressure, mixed refrigerant cooling reference temperature and the pinch temperature of cryogenic plate fin heat exchanger. The simulation results exhibited considerable reduction of specific total energy consumption. Therefore, the proposed liquefaction cycles have a simple topology, hence lower capital cost and compacter plant layout, which is compatible for power-efficient, offshore, floating liquefied natural gas liquefaction plants.

Adsorption is a widely used technique for the removal of pharmaceutical organic micro-pollutants. In this article, calcined gypsum (CaSO4.0.5H2O) was utilized for the removal of ibuprofen medicine from polluted water. Several factors including the adsorbent dose, contact time, and temperature were studied. The influence of the ions in the solution on the precipitation of gypsum and its setting time was investigated because it significantly affects the percentage removal. The fast the setting time gypsum, the lower the percentage removal precipitate. From thermodynamic parameters, the negative values of ?Go indicated a spontaneous and physisorption of ibuprofen onto the calcined gypsum surface. Kinetic study results showed that the adsorption of ibuprofen on gypsum follows pseudo-first-order kinetics.

Groundwater quality is an issue of national concern in Jordan since it is the main water source for drinking, agriculture and industrial purposes. In this context, an attempt has been made to determine the suitability of groundwater in the Yarmouk Basin in Jordan for drinking purposes using the weighted arithmetic water quality index approach with the respect to the Jordanian standards for drinking water. Groundwater quality records from 15 sampling stations spread across Yarmouk Basin during 2008- 2015 are used. Seven physical and chemical parameters are selected to calculate the water quality index. These parameters are pH, total dissolved solids, total hardness, sulfates (SO4 -2 ), chlorides (Cl- ), nitrates (NO3 - ), and sodium (Na+ ). The relationship between the selected groundwater quality parameters is evaluated using the correlation coefficient. A strong relationship is found between several parameters such as Cl- with Na+ , total dissolved solids with Na+ , Cl- , TH and SO4 -2 and total hardness with SO4 -2. A moderate relationship is found between SO4 -2 with Na+ , TH with Cl- and Na+ , SO4 -2 with Cl- , Cl- with NO3 - and NO3 - with Na+ . Also, the mean concentration values of the physical and chemical parameters are almost below the maximum allowable level based on Jordanian standards for drinking except for two sampling locations. According to water quality index scale classification, the groundwater quality of the studied locations is in the excellent to poor water range with computed mean water quality index values range from 26.3 to 107.93. Out of 15 studied locations, ten locations are classified in the ‘Excellent water’ class, four locations as a “Good water” class, one as a “Poor water” class. None of the studied locations are classified in the “Very poor water” class and “Water unsuitable for drinking purpose” class. Temporal variations and spatial distribution of groundwater quality in Yarmouk Basin based on WQI are also evaluated. The WQI spatial distribution map clearly showed the best locations for drinking water in the Yarmouk Basin. Water quality indices are used to provide theoretical support to water managers and policymakers for proper actions on groundwater quality management.

The aim of this study is to examine methanol poisoning cases from the medico-legal point of view. The records of the National Institute of Forensic Medicine (NIFM)-Jordan were reviewed retrospectively for all methanol poisoning from January 2007 to January 2008. It was found that methanol poisoning comprise 0.92% of all forensic autopsies (n: 16), 87.5% of the cases were males, the mean age of victims was 35, range 14-56 years, the largest age group was 30-39 years accounted for (31.25%, 5 cases) followed by the age group 40-49 years (25%, 4 cases). The methanol blood concentrations ranged widely from 56 to 400 mg/dL. There were 12 cases (75%) with the methanol blood concentrations over 100mg/dL. Fifteen cases were found dead and one was admitted to hospital before death. The main cause of death in all cases was due to methanol intoxication as underlining cause of death

Because Analogy is considered as a double-edged sword, thermal engineers should be cautious in analogical maneuvering between electrical and thermal domains in order not to be slipped into building misconceptions about thermal resistance concept. Composite wall thermal resistance (CWTR) modeling is one of the practical examples that illustrates the probability of misusing analogy. Heat transfer undergraduate textbooks coverage of CWTR suffers a lean towards “cookbook” coverage that reports concise statements that lack deep clarification and illustration. Transparent Thinking Approach (TTA) is employed to present a detailed calculation and illustration of a typical CWTR modeling based on isothermal and adiabatic assumptions. The calculation of a typical CWTR for different values of wall thermal conductivities shows that the difference in parallel walls thermal conductivity is creating a large discrepancy that may reach 80% between heat flows calculated based on isothermal and adiabatic assumptions. It is found that for a series-parallel arrangement of composite walls with high difference in parallel wall thermal conductivity values, the true value of heat flow is bracketed between the isothermal and adiabatic heat flow values. The transparent way of presenting CWTR modeling can be readily included in any standard heat transfer textbook and result in greatly enhancing CWTR modeling coverage.

A low-cost and enhanced thermal properties composite material for sensible heat storage in solar thermal energy storage applications is introduced. The proposed material is produced primarily for small scale solar thermal applications. However, it can be utilized for large scale solar thermal plants. The material has the advantages of high thermal conductivity and large energy storage density. The introduced material is composed of a mixture of cement and cast-iron particles. To obtain an optimal mixture, different samples of the material are prepared with different ratios of the cement-iron weights. The thermal conductivity of the produced samples is measured by using the linear heat conduction method. The specific heat capacity of the produced mixtures is calculated by using the Rule of the mixture. The obtained results show that the introduced material has a significant enhancement in thermal conductivity. Where, thermal conductivity as high as ~6.0 W/m.K and energy storage density as high as ~788 Joule/cm3 are achieved. The estimated volume energy density is ~89% higher than that of water. The produced material has the advantage of high energy volume density, being unhazardous, chemically stable, eco-friendly, easy to fabricate, and integrate with solar thermal energy systems and is a low-cost material.