Vapor Liquid Equilibria for Ionic Liquid/Ethanol/Water Systems and the Effect of Anion Hydrolysis

The performance of two tetrafluoroborate-based ionic liquids (ILs) as entrainers in the dehydration of water/ethanol azeotropic mixtures was evaluated. Isobaric vapor-liquid equilibrium (VLE) data were measured for the systems ethanol/water/1-butyl-3-methyl imidazolium tetrafluoroborate and ethanol/water /n-butylpyridinium tetrafluoroborate including the azeotropic region. VLE data for the ethanol/water, ethanol/IL, and water/IL binary mixtures were obtained at 100 kPa. The hydrolysis of the tetrafluoroborate anion was studied for both types of ILs by ¹⁹F NMR analysis. The hydrolysis of the tetrafluoroborate anion does not have much effect on the ethanol/water VLE. The ¹⁹F NMR analysis indicated that hydrolysis occurred at high mole fractions of water.     

Two safety coefficients for a typical 13 × 13 annular fuel assembly

Recently, annular fuel rods are proposed for both PWRs and BWRs to achieve more average power density and therefore many neutronic as well as thermal-hydraulics calculations have been made to find more performance in the future reactors. Also, some safety margins are studied for the proposed uranium-nitride (and/or other fissile materials) annular pins. Our aim herein is to study two important safety coefficient of the annular fuel core. These are “prompt reactivity” and “power coefficients”, where all investigations are made using MCNP-5 code. Also, a thermal resistance model for annular fuel heat transferring were given and then we have calculated its (a case) thermal resistance numerically.     

Effects of E‐beam irradiation and vacuum packaging on biogenic amines formation in common carp (Cyprinus carpio) fillets

The effects of vacuum packaging followed by E‐beam irradiation treatment on the shelf life of common carp (Cyprinus carpio) fillets were studied by measuring biogenic amines and sensory analysis. Samples were irradiated at doses of 0.10, 0.50, 1.0 and 2.0 kGy. Putrescine, cadaverine, histamine and tyramine showed very good correspondence with the irradiation dose and the time of storage. Spermine, spermidine, tryptamine and phenylethylamine did not show statistically significant changes with the time of storage. According to the sensory assessment and biogenic amines index (BAI), the shelf life of unirradiated common carp fillets was found to be approximately seven days. The 1 and 2 kGy irradiation doses extended the shelf life of samples up to 66 and 77 days, respectively. High values of correlation coefficients (r < ?0.86) between BAI and sensory evaluation indicated that BAI could be considered as a quality indicator of common carp fillets.     

Development of a Hybrid Data Driven Model for Hydrological Estimation

High and low stremflow values forecasting is of great importance in field of water resources in order to mitigate the impacts of flood and drought. Most of water resources models deal with the problem of not being flexible for modeling maximum and minimum flows. To overcome that shortcoming, a combination of artificial neural network (ANN) models is developed in this study for monthly streamflow forecasting. A probabilistic neural network (PNN) is used to classify each of the input-output patterns and afterward, the classified data are forecasted using a modified multi-layer perceptron (MMLP). In addition, the performance of the MLP and generalized regression neural network (GRNN) in streamflow forecasting are investigated and compared to the proposed method. The findings indicate that the R² associated with the suggested model is 46 and 80% higher compared to MLP and GRNN models, respectively.     

Investigation and numerical analysis of strain distribution in the twist extrusion of pure aluminum

The effects of performing three twist extrusion passes on high purity aluminum samples were studied in this paper in regard to numerical analysis and experimental studies. The finite element analysis of the von-Mises stress and the equivalent plastic strain in the outer longitudinal and transverse cross-sections, which are parallel and normal to the billet axis respectively, was carried out. The simulation results showed that the end of the workpiece underwent more equivalent plastic strains in contrast to the head of the sample. Moreover, the corner regions experienced more strains than the center zone did. However, the heterogeneity in strain distribution in both longitudinal and transverse cross-sections decreased by performing the sequential twist extrusion passes. The experimental outcomes such as microstructure evolutions, microhardness and tensile tests validated the simulation results.     

An analytical model for production data analysis of under saturated oil reservoirs subjected to edge aquifer

Analysis of production data is an important method for estimating recoverable reserves and probable life of the reservoirs. Robust techniques for analysis of production data have been developed and widely used for many years. These methods range from the traditional Arps decline method to modern production data analysis. The most recent techniques are based on material balance time to account for variable operating conditions. In these methods, production rate and flowing bottom hole pressure must be known. A major limitation of many existing modern techniques is volumetric assumption of the reservoir.This paper presents a new model that accounts for non-volumetric effects of edge aquifers on production data analysis of single phase oil reservoirs by defining a new material balance time function. This new time function and material balance time help us to introduce flowing material balance (FMB) equations for such reservoirs. Validity of these equations is justified using analytical solutions. For development of analytical solutions, special simplifying assumptions are considered. To justify these assumptions, comparison is made using a commercial numerical reservoir simulator across some ranges of reservoir parameters.Furthermore, based on the validated FMB equations and obtained analytical flow equations, specific procedures are developed for parameter estimation of such reservoirs. The use of these procedures in estimation of oil in place and reservoir external radius is demonstrated using synthetic examples. On the basis of the considered assumptions, the proposed procedures cannot be applied to multi-phase flow conditions, reservoirs with other types of aquifer (such as bottom aquifer), and gas reservoirs.We also show that the given FMB equations are applicable for any irregularly shaped reservoir which is partially contacted with a non-cylindrical limited edge aquifer. For such reservoir geometries, numerical solution is used for justification. This is followed by introducing a simple equation for predicting average reservoir pressure.     

Synthesis and characterization of new poly(ether–ester–imide)s as a generation of soluble and thermally stable polymers

A new-type of dicarboxylic acid 6 was synthesized from the reaction of 1,4-bis[4-aminophenoxy]butane 4 with trimellitic anhydride 5 in a solution of glacial acetic acid/pyridine (Py) at refluxing temperature. 1,4-Bis[4-nitrophenoxy]butane 3 was prepared by reaction of 4-nitrophenol 1 with 1,4-dibromo butane 2 in N,N-dimethylformamide (DMF) solution. Then dinitro 3 was reduced to 1,4-bis[4-aminophenoxy]butane 4 by using 10% Pd–C, ethanol, and hydrazine monohydrate. So six new thermally stable and organosoluble poly(ether–ester–imide)s (PEEIs) 8a–f with good inherent viscosities were synthesized by the direct polycondensation reaction of new 1,4-bis[4-(trimellitimido)phenoxy]butane 6 with several aromatic diols 7a–f through direct polycondensation using tosyl chloride (TsCl)/pyridine (Py)/DMF system as condensing agent. The resulted polymers were fully characterized by means of FTIR and ¹H NMR spectroscopy, elemental analyses, inherent viscosity, solubility tests, differential scanning calorimeter (DSC), thermogravimetric analysis (TGA), and derivative of thermogravimetric (DTG).