Numerical Investigation of Bubble Movement in Magnetic Nanofluids

Department of Mechanical EngineeringIn this study, the idea to generate electrical energy by using waste heat is suggested. In this idea, the electrical energy can be generated by a magnetic nanofluid and bubble movement. Thus, bubble movement in a magnetic fluid is numerically investigated using the commercial CFD package COMSOL Multiphysics for effective energy generation. The slug characteristics are also investigated because it can be generated by merging each bubble. The level-set method and phase-field method are used to simulate the bubble and slug movement, respectively. For the investigation, EFH1 and EFH3 are selected as working fluidsthey are commercial magnetic fluids manufactured by Ferrotec, and each fluid contains different amounts of magnetic particles. The solvers are validated by comparing the numerical results with previous research studies and experimental data for reliable results. The properties of a fluid can be changed by solid particles if the particles are dispersed in the fluid. These particles can affect the bubble and slug characteristics, such as shape, velocity and wake. Thus, the effect of solid particles is first studied by observing the bubble and slug movement in each magnetic fluid. In the slug investigation, the effects of some parameters are also studied, such as slug length and liquid backflow. The patterns of bubble and slug movement are investigated to predict the effective condition for the energy generation. The effective bubble and slug movements are predicted by evaluating the disturbance of the surrounding magnetic fluid for each flow pattern. A magnetic force can be created, and it can affect any phenomena when the magnetic field is applied to the system. Thus, the effect of the magnetic force is also investigated because the magnetic field should be applied to the system for the electrical energy generation. Finally, the important factor for energy generation is identified by comparing the results.ope

Multiscale Biofluidic and Nanobiotechnology Approaches for Treating Sepsis in Extracorporeal Circuits

Infectious diseases and their pandemics periodically attract public interests due to difficulty in treating the patients and the consequent high mortality. Sepsis caused by an imbalanced systemic inflammatory response to infection often leads to organ failure and death. The current therapeutic intervention mainly includes "the sepsis bundles," antibiotics (antibacterial, antiviral, and antifungal), intravenous fluids for resuscitation, and surgery, which have significantly improved the clinical outcomes in past decades; however, the patients with fulminant sepsis are still in desperate need of alternative therapeutic approaches. One of the potential supportive therapies, extracorporeal blood treatment, has emerged and been developed for improving the current therapeutic efficacy. Here, I overview how the treatment of infectious diseases has been assisted with the extracorporeal adjuvant therapy and the potential utility of various nanobiotechnology and microfluidic approaches for developing new auxiliary therapeutic methods

Combinatorics in N = 1 Heterotic Vacua

We briefly review an algorithmic strategy to explore the landscape of heterotic E8 \times E8 vacua, in the context of compactifying smooth Calabi-Yau three-folds with vector bundles. The Calabi-Yau three-folds are algebraically realised as hypersurfaces in toric varieties and a large class of vector bundles are constructed thereon as monads. In the spirit of searching for Standard-like heterotic vacua, emphasis is placed on the integer combinatorics of the model-building programme.Comment: 14 pages. An introductory review prepared for the special issue "Computational Algebraic Geometry in String and Gauge Theory" of Advances in High Energy Physic

Welfare Reform and the Devolution of Decision Making Authority: Changes in Administrative Infrastructure for TANF Implementation

The growing demand for welfare reform represented a devolution of authority from federal administration and enabled state governments to seek ways to improve efficiency and enhance coordination in managing Temporary Assistance for Needy Families (TANF) programs. This shift in authority from the federal government to the state and from the state to county administration empowered interagency collaboration and partnership by expanding organizational linkages between state agencies and local governments, nonprofit, and for-profit agencies for the shared goal of welfare reform.Based on a theoretical framework from New Public Management and governance theories, this research is a small-n comparative case study that explores how the shift in authority emerged at state and local administrative levels, and how states have changed TANF implementation structure in two states: New York and Pennsylvania. It also examines whether the evolution in TANF administrative infrastructure changed the decision making capacity of organizations at state and local welfare jurisdictions and contributed to economic self-sufficiency of TANF clients. The practices of Albany County, New York and Allegheny County, Pennsylvania are examined to explore how county government has implemented TANF programs in partnership with other organizations. This research conducts qualitative, quantitative, and network analysis using data from interviews, surveys, and archival records. It finds that state and county governments in New York and Pennsylvania have not substantially reinvented internal structures, but have expanded the collaboration and partnership with state or county sister agencies and nongovernmental organizations for improving efficiency. The experimentation of New York and Pennsylvania reveals that the involvement of other organizations made a substantial contribution to the decision making capacity of the organizations involved in TANF implementation. It did not yet contribute significantly to an increase in family income for TANF clients. The data also show that a larger proportion of TANF clients left welfare not for employment, but for other reasons. States sought to reduce welfare rolls without a thorough assessment of the impact of participation on the real lives of TANF clients and the reasons why clients left the program until the reauthorization in 2002. TANF clients still face difficult circumstances in becoming economically self-sufficient