FEDSM2003-45371 A STOCHASTIC REPRESENTATION OF PARTICLE BEHAVIOR IN GAS-LIQUID HORIZONTAL ANNULAR FLOW

ABSTRACT A stochastic method which uses a modified Langevin equation to represent the velocities of the fluid seen by a particle in a turbulent field is explored. Calculations of the dispersion of particles from a source on a wall agree with calculations at Re τ = 150 which use a DNS to represent the fluid velocity field. The paper demonstrates how wall source calculations can be used to analyze problems involving atomization and deposition, which are of interest in horizontal gas-liquid annular flows. INTRODUCTION A critical issue in developing a model for annular gasliquid flow in a horizontal system is the prediction of the effect of gravity on the spatial distribution of droplets, on the deposition constant and on the droplet turbulence. This paper presents the results of numerical experiments aimed at studying these phenomena. Because of gravity the liquid film on the wall has a nonuniform distribution. Droplets are torn from the film and undergo trajectories which depend on gravity and on the fluid turbulence. Eventually, they deposit on the wall. The drop concentrations are approximately constant in planes perpendicular to the gravity vector. They decrease in the vertical direction because of the effect of gravity. The local deposition rate depends on local concentration at the wall and on the local deposition constant. A discussion of the modeling of entrainment in a horizontal annular flow has been presented by Pan and Hanratty [1]. Baik and Hanratty [2] have recently explored a mechanism for the transition to annular flow in large diameter pipes which considers whether droplet mixing is sufficient to form a film on the top of the pipe. The results of this study are used to address theoretical issues raised in these papers. The simplified system that is considered is a horizontal channel for which droplets enter the field from the bottom wall. Most of them eventually deposit on the bottom wall. A smalle

Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)

Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

Enzymatic Saccharification and Ethanol Production of Xylem From Purwodadi Botanical Garden Trees

Recent studies have revealed that sengon (Paraserianthes falcataria) xylem consists of soft walls which are easily hydrolysable with a commercial cellulase preparation. We felt it important to determine the saccharification levels for Fast-growing tropical trees, of which sengon, one of the Fastest growing tree species in Indonesia, was used as the control wood species. The aim of this study was to screen and evaluate the xylem of Purwodadi Botanical Garden trees for saccharification in order to assess their potential usefulness in bioethanol production. Saccharification and fermentation were first examined in the xylem derived from the branches of 32 trees. The xylem was then milled into powder using a ball mill, and the powdered xylem was digested with a commercial cellulase preparation (Accelerase, Palo Alto, USA) derived from Trichoderma viride. The levels of enzymatic hydrolysis of cellulose and ethanol production were higher for Firmiana malayana and Pterocarpus indicus than for sengon