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Prediction and Correlations of Residual Entropy of Superheated Vapor for Pure Compounds
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Prediction of accurate values of residual entropy (SR) is necessary step for the
calculation of the entropy. In this paper, different equations of state were tested for the
available 2791 experimental data points of 20 pure superheated vapor compounds (14
pure nonpolar compounds + 6 pure polar compounds). The Average Absolute
Deviation (AAD) for SR of 2791 experimental data points of the all 20 pure
compounds (nonpolar and polar) when using equations of Lee-Kesler, Peng-
Robinson, Virial truncated to second and to third terms, and Soave-Redlich-Kwong
were 4.0591, 4.5849, 4.9686, 5.0350, and 4.3084 J/mol.K respectively. It was found
from these results that the Lee-Kesler equation was the best (more accurate) one
compared with the others, but this equation is sometimes not very preferable. It was
noted that SRK equation was the closest one in its accuracy to that of the Lee-Kesler
equation in calculating the residual entropy SR of superheated vapor, but it was
developed primarily for calculating vapor-liquid equilibrium and to overcome this
problem, efforts were directed toward the possibility of modifying SRK equation to
increase its accuracy in predicting the residual entropy as much as possible. The
modification was made by redefining the parameter α in SRK equation to be a
function of reduced pressure, acentric factor, and polarity factor for polar compounds
in addition to be originally function of reduced temperature and n parameter –which is
also function of acentric factor– by using statistical methods. This correlation is as
follows:

α =[1+n(γ)]2  , γ=-0.920338Pr-0.34091 +0.064049Tr4 ω +0.370002ω-Pr0.996932 Tr-4x
This new modified correlation decreases the deviations in the results obtained by
using SRK equation in calculating SR when comparing with the experimental data.
The AAD for 2791 experimental data points of 20 pure compounds is 4.3084 J/mol.K
while it becomes 2.4621 J/mol.K after modification. Thus SRK equation after this
modification gives more accurate results for residual entropy of superheated vapor of
pure 20 compounds than the rest of the equations mentioned above.

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Publication Date
Sun Sep 01 2013
Journal Name
Baghdad Science Journal
High performance liquid chromatographic method for the determination of guaifenesin in pharmaceutical syrups and in environmental samples
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A simple, precise, rapid, and accurate reversed – phase high performance liquid chromatographic method has been developed for the determination of guaifenesin in pure from pharmaceutical formulations.andindustrial effluent. Chromatography was carried out on supelco L7 reversed- phase column (25cm × 4.6mm), 5 microns, using a mixture of methanol –acetonitrile-water: (80: 10 :10 v/v/v) as a mobile phase at a flow rate of 1.0 ml.min-1. Detection was performed at 254nm at ambient temperature. The retention time for guaifenesin was found 2.4 minutes. The calibration curve was linear (r= 0.9998) over a concentration range from 0.08 to 0.8mg/ml. Limit of detection (LOD) and limit of quantification ( LOQ) were found 6µg/ml and 18µg/ml res

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Publication Date
Wed Jan 01 2025
Journal Name
Iraqi Journal Of Applied Physics
Structural and Morphological Characteristics of PEKK-Coated Titanium Disks by RF Magnetron Sputtering for Implant Osteointegration Application
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Pure grade II titanium disks were coated with a thin coating of polyetherketoneketone (PEKK) polymer by RF magnetron sputtering using either nitrogen or argon gas. Sputtering technique was employed at 50 W for one hour at 60°C with continuous flow of nitrogen or argon gas. Field-emission scanning electron microscopy (FE-SEM) showed a continuous, homogeneous, rough PEKK surface coating without cracks. In addition, cross-sectional FE-SEM revealed an average coat thickness of 1.86 μm with argon gas and 1.96 μm with nitrogen gas. There was homogenous adhesion between the coating layer and substrate. The elemental analysis of titanium substrate revealed the presence of carbon, titanium, and oxygen. The RF magnetron sputtering with argon or ni

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Publication Date
Tue Oct 24 2023
Journal Name
Environmental Engineering Research
Exploring electromembrane extraction and liquid membrane for efficient removal of heavy metals from aqueous solutions: An overview
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Environmental pollution is experiencing an alarming surge within the global ecosystem, warranting urgent attention. Among the significant challenges that demand immediate resolution, effective treatment of industrial pollutants stands out prominently, which for decades has been the focus of most researchers for sustainable industrial development aiming to remove those pollutants and recover some of them. The liquid membrane (LM) method, specifically electromembrane extraction (EME), offers promise. EME deploys an electric field, reducing extraction time and energy use while staying eco-friendly. However, there's a crucial knowledge gap. Despite strides in understanding and applying EME, optimizing it for diverse industrial pollutant

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Publication Date
Tue Nov 09 2021
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Murabaha for real estate and its reflection on the profitability of Al-Nahrain Islamic Bank: applied research
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The Islamic Bank of Al-Nahrain offers a formula for financing the purchase of real estate through a deferred sale contract, through Murabaha to the order to buy, and the payment of the price is in the form of instalments that include (the purchase price of the profit and the mutual agreement on the real estate). This research aims to show the reflection of real estate murabaha on the bank's investments, by measuring the effect of real estate murabaha on the profits achieved by the Islamic Bank of Al-Nahrain Bank. The growth of 'real estate murabaha' realized from the 'amounts granted by Bank X, in addition to analyzing the financial ratios of profitability indicators, including (return on deposits Y2) and for the years (2016 - 20

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Publication Date
Wed Jun 01 2022
Journal Name
Iranian Journal Of Chemistry And Chemical Engineering
The Thermal Pre-processing Technique of the Bio-waste for Contaminated Water Treatment: Histological and Experimental Study
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The current study suggested a thermal treatment as a necessary proactive step in improving the adsorption capacity of bio-waste for contaminants removal in wastewater. This approach was based on the experimental and histological investigation of biowaste pods shell. This investigation showed that these shells compose of parenchyma cells that store secondary metabolites compounds produced from cells were exhibited in present study. The results also reported that these compounds are extracted directly from the cells as soon as they are exposed to an aqueous solution, hampering their use as an adsorbent material. The increase in the weight of bio-waste adsorbent at unit liquid volume increases the production of secondary metabolites compounds

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Publication Date
Sat Jun 01 2013
Journal Name
Int. J. Nanoelectronics And Materials
Comparsion of the physical properties for CdS and CdS doped PVA thin films prepared by spray pyrolysis
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Publication Date
Tue Dec 01 2015
Journal Name
Journal Of Engineering
Calibration and Verification of the Hydraulic Model for Blue Nile River from Roseires Dam to Khartoum City
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This research represents a practical attempt applied to calibrate and verify a hydraulic model for the Blue Nile River. The calibration procedures are performed using the observed data for a previous period and comparing them with the calibration results while verification requirements are achieved with the application of the observed data for another future period and comparing them with the verification results. The study objective covered a relationship of the river terrain with the distance between the assumed points of the dam failures along the river length. The computed model values and the observed data should conform to the theoretical analysis and the overall verification performance of the model by comparing i

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Publication Date
Thu Nov 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Comparison of Multistage and Numerical Discretization Methods for Estimating Parameters in Nonlinear Linear Ordinary Differential Equations Models.
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Many of the dynamic processes in different sciences are described by models of differential equations. These models explain the change in the behavior of the studied process over time by linking the behavior of the process under study with its derivatives. These models often contain constant and time-varying parameters that vary according to the nature of the process under study in this We will estimate the constant and time-varying parameters in a sequential method in several stages. In the first stage, the state variables and their derivatives are estimated in the method of penalized splines(p- splines) . In the second stage we use pseudo lest square to estimate constant parameters, For the third stage, the rem

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Publication Date
Sun Jan 01 2023
Journal Name
E3s Web Of Conferences
Assessments and Historical Changes the Water Quality of Sawa Lake, Southern Iraq for the Period 1977-2020
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This investigation pertains to the evaluation of water quality in SAWA Lake, located in the Al-Muthanna province of Southern Iraq, from 1977 to 2020. Understanding the water quality and assessments of this Lake is of great importance. The Lake is home to small, transparent, blind fish measuring approximately 10 cm and is often referred to as the "wonderful" or "strange" Lake due to its many unique features. The study focuses on several elements to represent water quality, including total dissolved solids (TDS), electrical conductivity (EC), pH, and temperature (T), which were measured directly in the field. Additionally, scientific concepts such as K+, Ca2+, Cl-, HCO

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Publication Date
Fri Jan 24 2020
Journal Name
Petroleum And Coal
Evaluation of Geomechanical Properties for Tight Reservoir Using Uniaxial Compressive Test, Ultrasonic Test, and Well Logs Data
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Tight reservoirs have attracted the interest of the oil industry in recent years according to its significant impact on the global oil product. Several challenges are present when producing from these reservoirs due to its low to extra low permeability and very narrow pore throat radius. Development strategy selection for these reservoirs such as horizontal well placement, hydraulic fracture design, well completion, and smart production program, wellbore stability all need accurate characterizations of geomechanical parameters for these reservoirs. Geomechanical properties, including uniaxial compressive strength (UCS), static Young’s modulus (Es), and Poisson’s ratio (υs), were measured experimentally using both static and dynamic met

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