CARBON DIOXIDE MINIMUM MISCIBILITY PRESSURE ESTIMATION (CASE STUDY)

Carbon dioxide flooding is considered to be one of the most effective enhanced oil recovery methods for the light oil reservoirs. Depending on the operating pressure, the process might be miscible or immiscible. Minimum miscibility pressure (MMP) is the most important parameter for assessing the applicability of any miscible gas flood for an oil reservoir. The miscibility condition is determined by conducting displacement tests at various pressures and the recovery is expected to improve as the displacement pressure increases, and then stays almost constant above the MMP. In this study, the MMP of pure carbon dioxide and an Iranian oil reservoir is estimated using slim-tube test. The experiment is performed under constant CO2 injection rate anddifferent displacement pressures above the bubble point pressure; input and output pressures are continually monitored during the test; the effluent liquid is flashed to atmospheric conditions and produced gases are passed through gas chromatography for compositional analysis. Volumetric oil recovery is measured, and oil recovery is plotted against the injection pressure at a 1.2 pore volume of the injected fluid. The results show that the oil recovery is more than 90% of original oil in place for all the pressures with a constant slope above the bubble point pressure. Therefore, MMP is considered to be equal to the bubble point pressure. In addition to the plot of oil recovery versus pressure, miscibility is also confirmed by the effluent gas composition, slim-tube pressure drop, and visual observations of phase behavior. The single phase high pressure fluid at the outlet of slim-tube, the small pressure drop across it, and no methane bank in the composition of effluent gas indicate that the miscibility is completely achieved. The experimental results are validated by modeling the test using a fully compositional simulator. The effect of varying CO2 mole fraction in the injected fluid is also investigated. The results show that an increase in CO2 mole fraction of the injected gas significantly decreases MMP. </span

A Structural Model of Relationship between Posttraumatic Growth and Death Attitudes in People with Cancer with Mediating Role of Cognitive Flexibility

Background and Aim: Cancer is a fatal disease that can affect various aspects of life, including personal, family and social life, and can destroy a person's performance. The present study was conducted with the aim of investigating the mediating role of cognitive flexibility in the relationship between post-traumatic growth and attitude towards death in people with cancer. Materials and Methods: The present study was descriptive-correlational and structural equation modeling. The statistical population of the present study includes cancer patients in Tehran in 1401. Among these patients, 120 people were selected as a sample and they were asked to answer the post-traumatic growth questionnaire, death attitude scale and cognitive flexibility questionnaire. Results: The research results showed that the correlation coefficient between death attitude with cognitive flexibility (0.38) and post-traumatic growth (0.27) is significant at 0.01. Also, cognitive flexibility had a mediating role in the relationship between post-traumatic growth and death attitude in people with cancer. Conclusion: Based on this, in the relationship between post-traumatic growth and death attitude in people with cancer, cognitive flexibility had a mediating role. Therefore, post-traumatic growth through increasing the level of cognitive flexibility can help to improve the attitude towards death in people with cancer

Leisure Activities and Mental Health among Aging People in Tehran, Iran

Introduction: Leisure activities are common among the elderly, however the effect of such activities on their mental health is poorly defined and not underpinned by strong evidence. This study aims to determine the prevalence of leisure activities and its relation to mental health in the elderly. Methods: A cross- sectional study was conducted and 400 community dwelling older adults 60 years and more with appropriate cognitive function (Abbreviated Mental Test score 7 and more), were recruited through multi-stage stratified cluster sampling in Tehran, Iran . Data was gathered by demographic questionnaire and General Health Questionnaire (GHQ). The primary outcomes to measure were the prevalence of leisure activities, and GHQ score in subgroups. Data were analyzed by Kolmogorov-Smirnov test, ANOVA, independent t-test and multiple linear regressions. Results: Of participants 62% were in their 7th decade (60-74 years), 56% (224) were female with mean age of 66.98±8.22 , and 44% (176) male with mean age of 66.98±8.22. GHQ scores showed 65% of participants had good mental health (0-23) and 35% had mental health problems(24 and more).Mean of GHQ score in participants (n=377) was 21.8± 11.37 (0-28). watching TV(77%), reading books( 40.3%), walking (31.5%) and taking trip(36%) were more interesting leisure activities among older adults .Women, single, unemployed, alone and illiterate older adults had statistically significant(P&le0.05) upper  GHQ scores. Participating in active leisure activities such as taking trip and cultural classes, participating in NGO activities, going to parks and gym and walking had significant relationships with good mental health (P&le0.05).  Conclusion: Encouraging older adults to participation in active leisure activities would be an effective intervention in mental health improvement. On the other hand understanding of relationship between type of leisure activities and mental health, provides evidence for policy makers and health care planners to offer and facilitate a context in which older adults can improve participation  in active leisure activities