Gas hydrate formation poses a significant threat to the production, processing, and transportation of natural gas. Accurate predictions of gas hydrate equilibrium conditions are essential for designing the gas production systems at safe operating conditions and mitigating the problems caused by hydrates formation. A new hydrate correlation for predicting gas hydrate equilibrium conditions was obtained for different gas mixtures containing methane, nitrogen and carbon dioxide. The new correlation is proposed for a pressure range of 1.7-330 MPa, a temperature range of 273-320 K, and for gas mixtures with specific gravity range of 0.553 to 1. The nonlinear regression technique was applied to develop the correlation based on 142 experimental data points collected from literature, validated with 85 data points not used for developing the correlation. The statistical parameters analysis showed an average absolute error (AAPE) of 0.2183, a squared correlation coefficient (R2) of 0.9978 and standard deviation (SD) of 0.2483. In addition, comparing the new correlation results with the experimental data and with those calculated by other correlations show an excellent performance for the investigated range.
This study was carried out in Baghdad (Al-Jadiriya) in 2006 by detecting ability of aquatic reed plant to remove heavy metals (Chromium) from waste water by batch process of adsorption with considering that acidic solution is best selection for such process with constant initial chromium concentration(60 mg/l),speed of shaking(300 rpm), temperature (30 Co) and constant contact time (4 h) but with different weights of adsorbent (reed) (0.5 ,1 ,2 ,3 and 4 )gm for each 100 ml volume of sample . The results showed that the percentage of the removed chromium were ( 8% ,17.5% ,31% ,40% and 50%) respectively for each sample according to the mass of adsorb
... Show MoreGas sensors based on titanium dioxide (TiO2) and zinc oxide (ZnO) nanocomposites are considered energy-saving devices that are utilized to find dangerous or harmful gases in an environment. The performance of nitrogen dioxide (NO2) gas sensors have been improved by spin-coating a TiO2 and TiO2:ZnO nanocomposite with varying concentrations (90TiO2:10ZnO, 70TiO2:30ZnO, and 50TiO2:50ZnO). To correlate structural properties with gas-sensing behavior, structural and morphological characterization has been done using FESEM, XRD, and EDX. Without any ZnO-specific crystalline phase, TiO2
... Show MoreWhen laser light incident on biological tissue, it is either reflected from the
surface of the tissue (e.g. the skin) or scattered inside the tissue or absorbed .The laser light will be
absorbed by water, hemoglobin and melanin. Absorption is also highly dependent on wave-length of
laser radiation. The absorbed light is converted into kinetic energy leading to laser effect that when
appropriately applied can produce reaction ranging from incision, vaporization to coagulation. Aim of
the study: To evaluate the efficiency of diode Laser 810 ± 20nm in treatment of oral lesions. Methods:
6 patients (2 females and 4 males) with different oral lesions were treated in the hospital of specialized
surgeries by the use of dio
Fracture pressure gradient prediction is complementary in well design and it is must be considered in selecting the safe mud weight, cement design, and determine the optimal casing seat to minimize the common drilling problems. The exact fracture pressure gradient value obtained from tests on the well while drilling such as leak-off test, formation integrity test, cement squeeze ... etc.; however, to minimize the total cost of drilling, there are several methods could be used to calculate fracture pressure gradient classified into two groups: the first one depend on Poisson’s ratio of the rocks and the second is fully empirical methods. In this research, the methods selected are Huubert and willis, Cesaroni I, Cesaroni II,
... Show MoreThe reduction in the rivers capacity is one the most important issue to give the decision maker an idea during the flood season. The study area included the rivers of the Al Atshan, Al Sabeel and Euphrates, which are surveyed with a length of 21, 5 and 20 km respectively. The Euphrates , the Atshan and Al Sabeel rivers were simulated by using HEC-RAS 5.0.3 software to study the real condition within the city of Assamawa. As well as the simulation was implemented by modifying the cross sections of the Euphrates and Al Sabeel rivers to increase their capacity to 1300 and 1200 m3/s respectively which are a flood discharges100 year return periods. The results showed that the maximum discharge capacity under real conditions o
... Show MoreThis research deals with the design and simulation of a solar power system consisting of a KC200GT solar panel, a closed loop boost converter and a three phase inverter by using Matlab / Simulink. The mathematical equations of the solar panel design are presented. The electrical characteristics of the panel are tested at the values of 1000 for light radiation and 25 °C for temperature environment. The Proportional Integral (PI) controller is connected as feedback with the Boost converter to obtain a stable output voltage by reducing the oscillations in the voltage to charge a battery connected to the output of the converter. Two methods (Particle Swarm Optimization (PSO) and Zeigler- Nichols) are used for tuning
... Show MoreDue to economic reasons or need for environmental conservatism or also preserve the natural resources; there has been an increasing shift towards the use of reclaimed asphalt pavement (RAP) materials in the pavement construction industry. Therefore, use the Reclaimed Asphalt Pavement (RAP) has been enormously increased in pavement construction and has been become common practice in many countries. Nevertheless, this is a relatively new concept in Iraq, and has to be remarked that is not used RAP in the production of HMA and this valuable material is mostly degraded. For this purpose, the reclaimed materials were collected from deteriorated pavement segments. The components of asphalt mixtures consist of: two asphalt penetration grades (40-5
... Show MoreIn the present study, free convection heat and mass transfer of fluid in a square packed bed enclosure is numerically investigated. For the considered geometrical shape, the left vertical wall of enclosure was assumed to be kept at high temperature and concentration while the opposite wall was kept at low temperature and concentration with insulating both the top and bottom walls of enclosure. The Brinkman– Forchheimer extended Darcy model was used to solve the momentum equations, while the energy equations for fluid and solid phases were solved by using the local thermal non-equilibrium (LTNE) model.Computations are performed for a range of the Darcy number from 10-5 to 10-1, the porosity from 0.5 to 0.9, and buoyancy ratio from -15 t
... Show MoreThe faujasite type Y zeolite catalyst was prepared from locally available kaolin. For prepared faujasite type NaY zeolite X-ray, FT-IR, BET pore volume and surface area, and silica/ alumina were determined. The Xray and FT-IR show the compatibility of prepared catalyst with the general structure of standard zeolite Y. BET test shows that the surface area and pore volume of prepared catalyst were 360 m2 /g and 0.39 cm3 /g respectively.
The prepared faujasite type NaY zeolite modified by exchanging sodium ion with ammonium ion using ammonium nitrate and then ammonium ion converted to hydrogen ion. The maximum sodium ion exchange with ammonium ion was 53.6%. The catalytic activity of prepared faujasite type NaY, NaNH4Y and NaHY zeolites