272 research outputs found

    Developing a Homeland Security Curriculum: A Case Study in Outcomes-Based Education Using the Delphi Method

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    The field of homeland security is a nascent discipline, and as such does not have a national accreditation body to promulgate a standardized, outcomes-based curriculum for future homeland security professionals seeking university degrees. This qualitative study was designed to identify a set of program-level, learning-based outcomes for an undergraduate degree in homeland security. The research project used a case study methodology to examine and validate the results of earlier studies on homeland security (HS) curriculum development. A consensus-driven, iterative Delphi technique was used to survey a purposive, convenience sample of homeland security experts to ascertain their ideas on what elements (i.e., knowledge, skills, and abilities) should comprise an undergraduate degree in HS, and then compare and contrast the data to earlier research projects. In addition, a 5-point Likert scale survey was distributed to gather basic demographics on the panel and to gauge the respondents\u27 thoughts regarding additional elements that should be included in an HS degree. The participants in the study identified a list of 15 core academic areas (CAAs) with a set of 50 associated program-specific objectives (PSOs), and a list of eight overarching program objectives (OPOs) that could comprise a standardized model homeland security curriculum. The proposed curriculum developed by this study enables an institution of higher learning to offer a unified, outcomes-based curriculum that would achieve a measurable level of knowledge, skills, and abilities a student must have to perform successfully as a homeland security professional in the 21st century. Additionally, adoption of such a model curriculum would be a precursor for an institution seeking program accreditation from a national accrediting body in the field of academic homeland security

    Motion and equilibrium of a spheromak in a toroidal flux conserver

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    A number of experiments have been performed on spheromaks injected into the empty vacuum vessel of the Caltech ENCORE tokamak (i.e., without tokamak plasma) [Phys. Rev. Lett. 64, 2144 (1990); Phys. Fluids B 2, 1306 (1990)]. Magnetic probe arrays (in a number of configurations) have been used to make single shot, unaveraged, in situ measurements of the spheromak equilibrium. These measurements are important because (i) they reveal for the first time the equilibrium structure of spheromaks in a toroidal geometry, (ii) they provide a reliable estimate of magnetic helicity and energy of spheromak plasmas used in injection experiments [Phys. Rev. Lett. 64, 2144 (1990)], and (iii) they constitute the first measurements of spheromak motion across and interaction with static magnetic fields (which are useful in corroborating recent theories). Probe measurements in the tokamak dc toroidal field show for the first time that the spheromak exhibits a ``double tilt.''The spheromak first tilts while in the cylindrical entrance region, emerging into the tokamak vessel antialigned to the dc toroidal field, then expands into the tokamak vacuum vessel, and finally tilts again to form an oblate (nonaxisymmetric, m=1) configuration. In addition, the spheromak drifts vertically in the direction given by Jcenter×Btok, where Jcenter is the unbalanced poloidal current that threads the center of the spheromak torus. Probe arrays at different toroidal locations show that the spheromak shifts toroidally (horizontally left or right) in the direction opposite that of the static toroidal field. In the absence of toroidal flux, the m=1 object develops a helical pitch, the sense of the pitch depending on the sign of the spheromak helicity. The spheromak equilibrium in the toroidal vessel is well fit by a pressureless infinite cylindrical model; however, there is evidence of deviation from m=1 symmetry because of toroidal effects, nonuniform J/B profile, and finite beta. Experiments performed in a test facility consisting of the spheromak gun and a replica of the entrance region (with a closed end) show that the spheromak is generated with its axis coaxial with that of the gun. Coherent, m=2 magnetic modes are observed during the formation stage rotating in the E×B direction at about 125 kHz (rotation velocity corresponding to 40% of the Alfvén speed)
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