Specifications for a coupled neutronics thermal-hydraulics SFR test case

Coupling neutronics/thermal-hydraulics calculations for the design of nuclear reactors is a growing trend in the scientific community. This approach allows to properly represent the mutual feedbacks between the neutronic distribution and the thermal-hydraulics properties of the materials composing the reactor, details which are often lost when separate analysis are performed. In this work, a test case for a generation IV sodium-cooled fast reactor (SFR), based on the ASTRID concept developed by CEA, is proposed. Two sub-assemblies (SA) characterized by different fuel enrichment and layout are considered. Specifications for the test case are provided including geometrical data, material compositions, thermo-physical properties and coupling scheme details. Serpent and ANSYS-CFX are used as reference in the description of suitable inputs for the performing of the benchmark, but the use of other code combinations for the purpose of validation of the results is encouraged. The expected outcome of the test case are the axial distribution of volumetric power generation term (q'''), density and temperature for the fuel, the cladding and the coolant

Numerical study of laminar magneto-convection in a differentially heated square duct

Magnetohydrodynamic pressure drops are one of the main issues for liquid metal blanket in fusion reactors. Minimize the fluid velocity at few millimeters per second is one strategy that can be employed to address the problem. For such low velocities, buoyant forces can effectively contribute to drive the flow and therefore must be considered in the blanket design. In order to do so, a CFD code able to represent magneto-convective phenomena is required. This work aims to gauge the capability of ANSYS© CFX-15 to solve such cases. The laminar flow in a differentially heated duct was selected as validation benchmark. A horizontal and uniform magnetic field was imposed over a square duct with a linear and constant temperature gradient perpendicular to the field. The fully developed flow was analyzed for Gr = 10^5 and Hartmann number (M) ranging from 10^2 to 10^3. Both insulating and conducting duct walls were considered. Strong dampening of the flow in the center of the duct was observed, whereas high velocity jets appeared close to the walls parallel to the magnetic field. The numerical results were validated against theoretical and numerical results founding an excellent agreement

Magnetohydrodynamic flow and heat transfer around a heated cylinder of arbitrary conductivity

The interaction of the liquid metal with the plasma confinement magnetic field constitutes a challenge for the design of fusion reactor blankets, due to the arise of MHD effects: increased pressure drops, heat transfer suppression, etc. To overcome these issues, a dielectric fluid can be employed as coolant for the breeding zone. A typical configuration involves pipes transverse to the liquid metal flow direction. This numerical study is conducted to assess the influence of pipe conductivity on the MHD flow and heat transfer. The CFD code ANSYS CFX was employed for this purpose. The fluid is assumed to be bounded by rectangular walls with non-uniform thickness and subject to a skewed magnetic field with the main component aligned with the cylinder axis. The simulations were restricted to Re = (20, 40) and M = (10, 50). Three different scenarios for the obstacle were considered: perfectly insulating, finite conductivity and perfectly conducting. The electrical conductivity was found to affect the channel pressure penalty due to the obstacle insertion only for M = 10 and just for the two limiting cases. A general increment of the heat transfer with M was found due to the tendency of the magnetic field to equalize the flow rate between the sub-channels individuated by the pipe. The best results were obtained with the insulating pipe, due to the reduced electromagnetic drag. The generation of counter-rotating vortices close to the lateral duct walls was observed for M=50 and perfectly conducting pipe as a result of the modified currents distribution

Three-dimensional MHD flow and heat transfer in a channel with internal obstacle

The magnetohydrodynamic flow and heat transfer of a liquid metal in a channel past a circular cylinder with walls of non-uniform conductivity were investigated. The applied magnetic field was transversal to the forced flow (x-direction) and coplanar with the obstacle, featuring non-null components in both the z- and y-directions. Moreover, the cylinder was displaced by the duct centreline toward the bottom wall and its surface was at uniform temperature, so that a ΔT was present between the obstacle and the fluid at the inlet. Non-uniform thickness for the duct-bounding walls is considered which leads to the promotion of jets close to the less-conductive surfaces. The flow features and heat transfer for this case were numerically investigated for different values of the Reynolds number (20 ≤ Re ≤ 80) and Hartmann number (0 ≤ Ha ≤ 100). Their effects on the flow features, pressure drop and heat transfer are analysed and discussed in detail in the present paper. The additional pressure drop introduced by the cylinder presence is found to be independent by Re and decreasing with Ha. Enhanced heat transfer is observed for an increasing Ha with NuMHD/Nu = 1.25. at Ha = 100 due to the augmented mass flow rate in the bottom sub-channel

Creating the Health Care Team of the Future: The Toronto Model for Interprofessional Education and Practice

[Excerpt] In 2000, the Institute of Medicine\u27s landmark report To Err Is Human launched the contemporary patient safety movement with its clarion call to the health care systems all over the globe to act to prevent the errors that kill over 100,000 patients a year and harm many thousands more in the United States alone. Ten years later, in 2010, the World Health Organization\u27s (WHO) Framework for Action on Interprofessional Education and Collaborative Practice was released, as was the Lancet Commission report Health Professionals for a New Century: Transforming Education to Strengthen Health Systems in an Interdependent World. In fact, over the past decade or more, studies have documented that, far from improving, in countries such as the United States and Canada, there has been little progress in preventing patient deaths and harm. Original calculations such as those done by the Institute of Medicine in 2000 are now considered to have been dramatic underestimations of the harm done to patients in health care institutions around the world. Although the complexity of today\u27s high-tech health care systems is often used as a rationalization for the maintenance of the status quo, all these groundbreaking reports argue that team-based, or interprofessional, care is a key strategy to move our current underperforming health care systems toward a more safe, efficient, integrated, and cost-effective model. Contemporary health care institutions do indeed have a bewildering number of players. Despite this, the responsibility for ensuring that patients receive the right care at the right time from the right providers relies on a few basic principles: Practitioners need to understand they are part of a diverse team. Practitioners must communicate effectively with the patient and family, as well as with other members of their team. Practitioners need to know what other team members do to limit duplication and prevent gaps in care. Practitioners need to know how to work together to optimize care so that the patient journey from inpatient care to home care, or from primary care to the specialist clinic is experienced as seamless. Since 2000, the eleven health professional programs at the University of Toronto and the forty-nine teaching hospitals associated with them have developed an Interprofessional Education and Care (IPE/C) program that begins in the first year of a health professional student\u27s entry into his or her program, continues through various educational activities throughout their studies, and straddles the education/practice divide. Over the past decade, the university and teaching hospital partners have been engaged in the co-development and support of the IPE curriculum for learners. They are also investing in the development of faculty and the ongoing training of staff to support and model collaborative practice and team-based care. What we have come to think of as the Toronto Model is integrated across all sites and professions and includes classroom, simulation, and practice education

Characterization of Cardiovascular Risk Factors People Living with HIV in a Veteran Population

Background: CVD is the leading cause of death in PLWH. HIV positive individuals have a 1.5-2-fold greater risk of CVD compared to uninfected individuals, even if complete viral load suppression is achieved. HIV-associated CVD has tripled over the past 20 years, yet scant data is available describing this population. We have characterized CVD risk factors and treatment in PLWH in order to assess and improve cardioprotective treatment. Methods: A retrospective EMR review was conducted for HIV positive patients enrolled at the McGuire VAMC between 12/2018 and 12/2019. Patients were excluded if labs were older than one year from follow-up. Patient demographics was collected along with characterization and treatment of their HIV, hypertension, diabetes, and dyslipidemia. Patient CVD status and risk factors were analyzed, and cardioprotective agent appropriateness was assessed. Results: 242 patients were included in this study. Overall, 91% had HIV viral load ≤ 200. 25% of patients had diabetes, of which 51% were controlled. 86% of patients achieved a blood pressure goal of ≤ 140/90. 40% of patients achieved LDL ≤ 70, with 56% of patients on a statin. 14% of patients had past history significant for cardiovascular event. Conclusion: Characterization of CVD in PLWH should be a high priority and treatment should be closely monitored due to the rising disease state burden. Lack of large clinical trials outlining treatment strategies in this aging population has hindered appropriate patient care. Intensified and targeted cardioprotective strategies are needed due to a high proportion of patients with uncontrolled CVD risk factors.https://scholarscompass.vcu.edu/gradposters/1064/thumbnail.jp

A comparison of computational methods for estimating estuarine production and respiration from diel open water dissolved oxygen measurements

Diel dissolved oxygen (DO) data were used to characterize seasonal, inter-annual, and longitudinal variation in production and respiration for the James River Estuary. Two computational methods (Bayesian and bookkeeping) were applied to these data to determine whether inferences regarding DO metabolism are sensitive to methodology. Net metabolism was sensitive to methodology as Bayesian results indicated net heterotrophy (production \u3c respiration) while bookkeeping results indicated net autotrophy (production \u3e respiration). Differences in net metabolism among the methods was due to low seasonal variation in respiration using the Bayesian method, whereas bookkeeping results showed a strong correlation between production and respiration. Bayesian results suggest a dependence on allochthonous organic matter (OM) whereas bookkeeping results suggest that metabolism is dependent on autochthonous OM. This study highlights the importance in considering the method used to derive metabolic estimates as it can impact the assessment of trophic status and sources of OM supporting an estuary