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.
In the last few years, the use of artificial neural network analysis has increased, particularly, in geotechnical engineering problems and has demonstrated some success. In this research, artificial neural network analysis endeavors to predict the relationship between physical and mechanical properties of Baghdad soil by making different trials between standard penetration test, liquid limit, plastic limit, plasticity index, cohesion, angle of internal friction, and bearing capacity. The analysis revealed that the changes in natural water content and plastic limit have a great effect on the cohesion of soil and the angle of internal friction, respectively. . On the other hand, the liquid limit has a great impact on the bearing capacity and
... Show MoreThe present study was carried out in the experimental in the nursery at Al – Dorah (Baghdad). During spring 2015 under natural environmental conditions in plastic house to evaluated the effect of different concentrations of IBA (100, 300, 500, 700 and 1000( mg/1 on different cutting position (basal, sub terminal and terminal) for different dipping times (24, 48) hours, on Cassia surattensis Burm. stem cuttings rooting. After 2 months of planting the results demonstrated that the basal cutting treated with 1000 mg/l IBA in 48 hours dipping time showed the earlier rooted period (4) weeks compared with control treatment 8 weeks. The same treatment also gave the highest mean rooting numbers 1.56per cutting and the highest mean rooting leng
... Show MoreBackground: Immunoassays are one of the oldest techniques used in diagnostic virology where a number of serologic techniques, with different degrees of sensitivity and specificity, for the detection of HCV antigens and their specific antibodies, have been developed.
Materials and methods: One hundred and four sera samples were collected from National Center for Blood Transfusion, Gastroenterology and Liver Diseases Hospital, Central Public Health Laboratories and Teaching Laboratories. According to the manufacturers practical instructions, many available methods for detecting Anti-HCV antibodies, including enzyme linked immunosorbent assay (ELISA), immunochromatographic assay (ICA), recombinant immunoblot
المستخلص:
في هذا البحث , استعملنا طرائق مختلفة لتقدير معلمة القياس للتوزيع الاسي كمقدر الإمكان الأعظم ومقدر العزوم ومقدر بيز في ستة أنواع مختلفة عندما يكون التوزيع الأولي لمعلمة القياس : توزيع لافي (Levy) وتوزيع كامبل من النوع الثاني وتوزيع معكوس مربع كاي وتوزيع معكوس كاما وتوزيع غير الملائم (Improper) وتوزيع
... Show MoreIn this article, an inverse problem of finding timewise-dependent thermal conductivity has been investigated numerically. Numerical solution of forward (direct) problem has been solved by finite-difference method (FDM). Whilst, the inverse (indirect) problem solved iteratively using Lsqnonlin routine from MATLAB. Initial guess for unknown coefficient expressed by explicit relation based on nonlocal overdetermination conditions and intial input data .The obtained numrical results are presented and discussed in several figures and tables. These results are accurate and stable even in the presense of noisy data.
The study of vegetative change of cities is one of the most important studies related to human life because of its direct correlation with the temporal conditions that occur. These include the economic problems that force people to move and look for job opportunities in the city, which leads to an increase in the population density of cities, especially for cities with an important economic and administrative location as in the capital city of Baghdad. In this study, the effect of the increasing in population density was analyzed on the urban planning of Baghdad city. The decreasing in vegetation was due to the increasing of urban areas on the outskirts of the city, which led to an increase in its area. Moreover, urban cities increased t
... Show MoreA mineralogical study using X-ray diffraction supported by scanning electron microscopic examination on the Paleocene- Eocene Kolosh and Gercus formations from northern Iraq is conducted to show the distribution of clay minerals and their paleoenvironmental implications. Smectite palygorskite, kaolinite, illite, and chlorite are commonly present in varying proportions within the Kolosh and Gercus formations. Association of smectite and chlorite in the claystone of the Paleocene Kolosh Formation refers to marine environment of this formation, whereas development of palygorskite fibers from smectite precursor may relate to post-depositional diagenesis. In addition, the abundance of illite and kaolinite in the Eocen
... Show MoreThis study aimed to evaluate the effectiveness of a novel concrete-encased column (CE) using small circular steel tubes filled with cementitious grouting material (GFST) as the primary reinforcement instead of traditional steel bars. The research involved three different types of reinforcement: conventional steel bars, concrete-filled steel tubes with 30% of the reinforcement ratio of steel bars, and concrete-filled steel tubes with the same reinforcement ratio as steel bars. Twenty-four circular concrete columns were tested and categorized into six groups based on the type of reinforcement employed. Each group comprised four columns, with one subjected to concentric axial load, two subjected to eccentric axial load (with eccentrici
... Show More