Experimental study of multiphase flow of viscous oil, gas and sand in horizontal pipes

Thesis (M.S.) University of Alaska Fairbanks, 2017The oil and gas industry relies on multiphase flow models and correlations to predict the behavior of fluids through wells and pipelines. Significant amount of research has been performed on the multiphase flow of different types of liquids with gases to extend the applicability of existing models to field-specific fluid conditions. Heavy oil and gas flow research commenced in the past decade and new correlations have been developed that define their flow behavior/regimes. This study aims to plant a foot in the quite deficient area of multiphase flow research that focuses on a sufficiently common situation faced by many heavy oil producing fields: the presence of sand in wells and pipelines. This study will be the first recorded attempt to understand the multiphase flow of heavy oil, gas, and sand. A 1.5" diameter multiphase flow loop facility capable of handling solids was designed and constructed for the study. Data logging instruments were calibrated and installed to be able to withstand the erosive effects of sand. The flow loop was leak and pressure tested with water and air. Three oils of 150, 196 and 218 cP viscosities were utilized to gather 49 single phase liquid, 227 two-phase liquid- air and 87 three-phase liquid, air and solid multiphase flow data points which included differential and absolute pressures, fluid flow rates, temperatures, liquid and composite liquid- solid hold- up data and photo and videotaping of the observed flow regimes. Validation of the setup was performed using single phase flow of oil and two-phase flow of oil and air. Sand was added in three different concentrations to the 218 cP oil and three-phase oil, gas and sand multiphase flow tests were performed. Flow patterns were identified and flow pattern maps were created using acquired data. No change was observed on flow pattern transitions by changing oil viscosities. Liquid hold- up and differential pressures were compared to observe the effect of changing oil viscosity and the presence of sand in varying concentrations on the two-phase flow of oil and gas and the three-phase flow of oil, gas and sand respectively. An increase in differential pressures was observed with increasing viscosities and the addition of sand. No changes in hold-up were seen with changing oil viscosities rather flow patterns impacted liquid hold-up significantly. The slug flow pattern was analyzed. Composite liquid-solid hold-up in slug flow were physically measured and predicted. Liquid slug lengths were predicted and compared with observed lengths using photo and videography techniques. Differential pressures and liquid hold-up were compared with existing multiphase flow models in the PIPESIM multiphase flow simulator to test model predictions against observed flow data. The dependence of differential pressure gradients and liquid hold-up on dimensionless variables was realized by performing normalized linear regressions to identify the most significant dimensionless groups and the results were given a mathematical form by proposing correlations for differential pressure and hold-up predictions. To the best of our knowledge, this study is the first attempt at systematically measuring pressure drop and liquid hold up during the three-phase flow of oil, gas and sand

NOVEL MECHANISMS OF β-ADRENERGIC SIGNALING IN PROSTATE CANCER PROGRESSION

Prostate cancer is the second leading cause of cancer death among American men. The American Cancer Society estimates that 180,890 men will be will be diagnosed with prostate cancer in 2016 in the USA. (http://www.cancer.org/cancer/prostatecancer/detailedguide/prostate-cancer-key-statistics). Androgen deprivation therapy (ADT) is the standard treatment for early stage prostate cancer. But most patients relapse with aggressive variants of prostate cancer, with survival time between 1-3 years. In order to develop cure for such aggressive variants of prostate cancer, our present understanding of the mechanisms underlying its progression needs to be advanced. Recently, it has been found that activation of β-adrenergic signaling pathway leads to aggressive variants of prostate cancer. β-adrenergic signaling involves the activation of β-adrenergic receptors (ADRBs), eventually leading to increased activation of cAMP response element-binding protein (CREB). Downstream targets of CREB activation in neuroendocrine differentiation as well as in neoangiogenesis are largely unknown, indicating that the underlying mechanisms of β-adrenergic signaling in prostate cancer progression are far from completely understood. For instance, while the epigenetic regulation by histone deacetylases 2 (HDAC2) is necessary for stress to induce cardiac hypertrophy, its mechanism are unknown in cancer progression. Similarly, another regulator of β-adrenergic signaling, GRK3 was recently shown to be a new critical regulator of prostate cancer progressionand tumor angiogenesis. However, mechanisms of GRK3 in prostate cancer progression and its regulation by ADRB2 signaling remain unknown. Our hypothesis is that GRK3 and HDAC2 are critical downstream effectors of β-adrenergic signaling-activated CREB in promoting prostate cancer progression. Here, we show that CREB directly activates GRK3 transcription by binding to its promoter and this up-regulation of GRK3 expression by ADRB2/CREB pathway is sufficient as well as necessary to induce the neuroendocrine differentiation of prostate cancer cells. We also show that downstream of chronic stress and ADRB2, CREB binds to HDAC2 promoter and activates its expression. HDAC2 further suppresses the expression of thrombospondin 1 (TSP1) in order to induce angiogenesis, thus acting as a mediator for the β-adrenergic signaling pathway. Here, we have introduced two new pathways acting downstream of the ADRB2/CREB axis. We show that the CREB/GRK3 axis leads to neuroendocrine prostate cancer progression. We have introduced a new paradigm that β-adrenergic signaling and epigenetic gene expression regulation may be working synergistically resulting in cancer progression

On the graph on a weyl group being an interval graph

We consider the graph on a Weyl group whose associated root system is arbitrary. It is shown that such a graph is an interval graph only when the associated root systems are of some particular types

Generating evidence on antibiotic use across human and animal health sectors using the World Health Organization’s Access, Watch, Reserve (AWaRe) classification: Exploratory pilot study in rural Pune, India

Background and Aim: Human antibiotic formulations in animal feed for therapeutic and non-therapeutic purposes have contributed to antimicrobial resistance worldwide; however, little evidence is available in low- and middle-income countries. We aimed to generate evidence of antibiotic use across the human and animal health sectors by investigating the overlap in antibiotic use in community settings in rural blocks of Pune District, India, following the World Health Organization’s (WHO) Access, Watch, Reserve (AWaRe) classification. Materials and Methods: An exploratory pilot study using a cross-sectional design in two randomly selected rural blocks of the Pune district included 138 interviews with general physicians (GPs, n = 62), pharmacists (n = 60), and veterinary practitioners (n = 16) using semi-structured interview schedules and the WHO AWaRe classification. IBM-Statistical Package for the Social Sciences, Version 21.0 software was used for descriptive statistics and to calculate the proportions of the different antibiotic groups. The WHO AWaRe classification was used to describe antibiotic use by the study participants and to assess the overlap in antibiotic use. Results: Our study provides evidence of an overlap in human and animal antibiotic use in rural community settings across the human and animal health sectors. Amoxicillin (access group), penicillin (access group), and ofloxacin (watch group) were used in both human and animal health. Amoxicillin and penicillin were used to treat common bacterial infections, ofloxacin was used to treat skin infections in humans and animals, and ofloxacin was used to treat pneumonia in animals and urinary bladder infections in humans. In contrast, azithromycin (watch group), cefixime (watch group), and amoxicillin (Access Group), with or without other antibiotics, were the most commonly used antibiotics by GPs in humans. Conclusion: We confirmed the overlap in antibiotic use across the human and animal health sectors in rural community settings, suggesting the need for interventions following the One Health approach. Further, research is required to assess the patterns of this overlap, as well as behavior, knowledge, and potential solutions to help avoid this overlap and prevent the rampant use of antibiotics in the animal and human health sectors in rural community settings