Gas hydrate formation is considered one of the major problems facing the oil and gas industry as it poses a significant threat to the production, transportation and processing of natural gas. These solid structures can nucleate and agglomerate gradually so that a large cluster of hydrate is formed, which can clog flow lines, chokes, valves, and other production facilities. Thus, an accurate predictive model is necessary for designing natural gas production systems at safe operating conditions and mitigating the issues induced by the formation of hydrates. In this context, a thermodynamic model for gas hydrate equilibrium conditions and cage occupancies of N2 + CH4 and N2 + CO4 gas mixtures at different compositions is proposed. The van der Waals-Platteeuw thermodynamic theory coupled with the Peng-Robinson equation of state and Langmuir adsorption model are employed in the proposed model. The experimental measurements generated using a cryogenic sapphire cell for the pressure and temperature ranges of (5-25) MPa and (275.5-292.95) K, respectively, were used to evaluate the accuracy of this model. The resulting data show that increasing nitrogen mole percentage in the gas mixtures results in decreasing of equilibrium hydrate temperatures. The deviations between the experimental and predictions are discussed. Furthermore, the cage occupancies for the gas mixtures in hydrate have been evaluated. The results demonstrate an increase in the cage occupancy for both the small and large cavities with pressure.
New compounds containing heterocyclic units have been synthesized. These compounds include 2-amino 5- phenyl-1,3,4-thiadiazole (1) as starting material to prepare the Schiff bases 2N[3-nitrobenzylidene -2 hydroxy benzylidene and 4-N,N-dimethyl aminobenzylidene] -5-phenyl-1,3,4-thiadiazole (2abc) , 2N[3-nitrophenyl, 2-hydroxyphenyl or 4-N,N-dimethylaminophenyl] 3-]2-amino-5-phenyl-1,3,4-thiadiazole]-2,3-dihydro-[1,3]oxazepine-benzo-4,7-dione] (3abc), 2N[3-nitrophenyl,2-hydroxyphenyl,4-N,N-dimethylaminophenyl]-3-[2-amino-5-phenyl-1,3,4-thiadiazole-2-yl]-2,3-dihydro-[1,3]oxazepine-4,7-dione[(4abc), 2-N-[3-nitrophenyl, 2-hydroxyphenyl or 4-N,N-dimethylaminophenyl]-3-[2-amino-5-phenyl-1,3,4-thiadiazole-2yl]-1,2,3-trihydro-benzo-[1,2-e][1,3] diaz
... Show MoreThe performance of single and two stage solar concentrator were studied ' " The ratio of the primary to the secondary mirrors diameter is taking to be 0.5, depending on the theoretical calculation for the accumulated energy by the concentrator with ratio between 0.0 to 0.9. The design of the systems were designed and examined by using a ray-tracing program. The efficiency of the single and the two stage concentrators are calculated and compared with and without cooling systems.
The research studies the sculptural formation in the third millennium: styles and trends, by taking the most important results of sculpture in the third millennium. The problem of the research is to search for the new sculptural formation in what it constitutes of social and human importance, and what are the important factors in forming the contemporary sculptural structure, and what is the mechanism of showing and producing the new formation. The research requires the study of the most important thing that the (sculptural formation in the third millennium styles and trends) represents. The importance of research depends on the importance of the sculptural formation after the twentieth century and the importance that the for
... Show MoreThe research is divided into three chapters, the first of them to the research problem and its importance and its purpose and its limits, while the second chapter review of contemporary sculpture as a vision and concept, The third chapter came to view the most important results reached by the search.
Contemporary Media Stylistics permits readers to explore a variety of methodological applications to data analysis. Recent developments in technology and media communication provide linguists and stylisticians with authentic data for analysis based on real-life communication.
HLA genes are associated with more than 100 diseases, including infectious diseases like HIV, and some cancers. Some autoimmune conditions, including diabetes and multiple sclerosis, are also linked to specific variations in the HLA. In MS, the immune system fails to distinguish between the body's tissues and foreign proteins resulting in it attacking myelin as if it were foreign. Several HLA genes have been found to influence the risk of developing MS. Some variants make an individual more likely to develop MS, whereas others may have a protective effect and decrease the risk. Although the precise genes involved in the development of multiple sclerosis are still not fully understood, research has identified one HLA gene that is mor
... Show MorePregnancy at an early age of life is a major challenge. The consequences of this problem have an impact on the quality of life of the young mother and her family, and determines an important risk for her offspring. The son of a teenage mother has, in general, greater risks than that of a mother of more than 20 years. The aim of this study is to determine the prevalence and outcome of teenage pregnancy. A descriptive data base study was conducted at Al-Elwia Maternity Teaching hospital in the period from January 1, 2019 to the end of June 2019 within the age between 12 and 19 years old. The mean age of the mother was 17.4 ±1.5 years. The mean age of the father was 23.9 ± 5.7 years with (69.5%) with Vaginal delivery and most of the
... Show MoreThe overlap between science and knowledge is a feature of the 21st century. This integration, which crosses the traditional boundaries between academic disciplines, has occurred because of the emergence of new needs and new professions. This overlap has overshadowed the arts in general and design in particular. The Design achievements have not been far away from the attempts of integration of more than one type or design application to produce new outputs unique in its functional and aesthetic character, including the terms of internal graphic design.
The researcher raises the question of the functional dimension of graphic design in the internal space, in order to answer it through the methodological framework, which includes th
... Show MoreThe research aims to identify the reasons that lead to asymmetry of information between economic unity administration and the parties that use accounting information such as shareholders, So, the ability to reach to the solutions that would reduce this problem, these factors have been divided into two types: the first one is the internal factors which represent the administration's desire in order to expand the self-interest of getting the profits and increase the value and competitive entity and investors to obtaining greater returns for their shares, so the second type is the external factors, which represent the failer that occurs in the laws and regula
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