Analysis Of Non-Conventional Radiological Terrorism

Nuclear terrorism has been a risk since the dawn of the first atomic bomb. Though state sponsored nuclear weapons development is of concern for countries, non-state sponsored terrorism with radiological material can be of even greater concern. This stems from the fact that the material is under less stringent or no safeguards and can readily change hands between different terrorist groups or innocent civilians may accidently come into contact with the material. Within this paper an analysis of previous accidents using orphan radiological sources, malicious use of orphan radiological sources, and how these sources could be used by terrorists is analyzed. Literature pertaining to doses received during theoretical dirty bomb attacks is reviewed and compared to potential consequences to the human body. With this review of literature complete, a methodology is created to generate realistic scenarios in which a non-conventional nuclear terrorist attack using radiological material could be carried out. These scenarios are re-created in MCNP models to quantify dose estimates civilians would receive. These scenarios include a source placed under a metro seat, a particulate source distributed in a children’s sandbox, a source placed in a government building waiting room, and a source placed in a bush next to a line at a theme park. These scenarios are designed to analyze changing different aspects of the situation to show how different sources, shielding, time, and placement could affect the dose and effectiveness of a terrorist attack. The scenarios showed that the individuals in the subway model and waiting room models received the highest dose with the sandbox model receiving the third highest dose and the theme park line receiving the lowest dose. These results are later discussed and the potential impact an attack of this type could have to those exposed. This ranges from medical impacts, such as acute radiation sickness, birth defects, increased cancer rates, economic impacts to society, and civil turmoil from a distrustful public. Lastly, a means of countering such an attack is analyzed from detection to prevention. This in total provides a comprehensive review of how an attack could occur, motives for such an attack, the impact of said attack, and how to prevent or mitigate the consequences of the attack

Rebuilt and Remade: The Florida Citrus Industry, 1909-1939

Prior to orange juice concentrate, Florida citrus was already an industrialized agricultural sector. This thesis explores the early-20th-century Florida citrus industry and demonstrates that contemporary farming practices were influential in advancing how citrus was produced, processed, worked, marketed, and regulated in early-20th-century Florida. Restarted after devastating freezes in 1894-1895, resolute Florida growers rebuilt their groves into marvels of large-scale citrus fruit production. Continuing a legacy in experimental crossbreeding, improved varieties of citrus were developed to lengthen the season and markets. Advocated by nurserymen and university educators, biological innovation helped the citrus thrive in the 1910s and 1920s from adverse weather effects, pests, and diseases. Scientists were agents of modernization whose research influenced its industrialization. With the inclusion of machines in the processing of citrus, technological innovation materialized significantly in Florida\u27s packinghouses by the 1930s. These changes affected the lives of agricultural workers and small growers. Whether by prejudice or by resisting collective efforts, big growers gained power and influence in the industry, Their power concentrated into the Florida Citrus Codes and Florida Citrus Commission in 1935, which effectively allowed large-scale growers to direct the industry\u27s development into the rest of the 20th century. In all, this reexamination into Florida citrus exemplifies the remaking of this industry into a modern agricultural system as well as the gradualism of southern agricultural modernization in early-20th-century America

Effectiveness of Additive Correction Multigrid in numerical heat transfer analysis when implemented on an Intel IPSC2

The effectiveness of the Additive Correction Multigrid (ACM) algorithm, a line-byline Tri-diagonal Matrix Algorithm (TDMA), and simple Gauss-Seidel (GS) iteration in numerical heat transfer analysis is investigated on a conventional single processor computer and on a distributed memory parallel computer. The performance of these methods is studied by solving a two-dimensional, steady heat conduction problem. The execution time of ACM on a single processor is proportional to the number of unknowns to the 1.5 power. This is in contrast to the execution time of the TDMA for which the execution time is proportional to the number of unknowns to the 2.0 power. The GS , TDMA and ACM algorithms are adapted to a model IPSC2 Intel hypercube which has a 32 processing nodes each with 8 MBytes oflocal memory. Because GS is a local method, it has almost perfect speed up, but it also converges more slowly than TDMA, The TDMA, on the other hand, is affected by domain decomposition to a greater extent than GS. As the number of processors used to solve the problem is increased, the execution times for GS and TDMA are essentially equal. Solving the model problem with 32 processors on a 192x192 grid resulted in parallel efficiencies of 95%, 80% and 78% for the GS, TDMA, and ACM algorithms, respectively. Though the parallel efficiency of ACM was the lowest of the three, the parallel ACM algorithm required an order of magnitude less time to solve the model than either parallel GS or parallel TDMA without multigrid

The Use of Theatre to Develop Social and Communication Behaviors for Students with Autism

Social and communication behaviors are often a focus of instruction for individuals with autism. A theatre rehearsal and production process is challenging and joyful work that nurtures the development of social and language skills. This study evaluated and described social and language behaviors for students with autism both before and after a 10-week theatre experience. The results indicated that, when compared with a control group, the students with theatre experiences had significant and positive changes in the development of social and language skills. Most particularly, these students had significant improvement in social responsiveness, acknowledgement of the perspective of others, and participation and cooperation. The theatre experiences led to positive changes in social and communication behaviors for students with autism

Is the Cepheus E Outflow driven by a Class 0 Protostar?

New early release observations of the Cepheus E outflow and its embedded source, obtained with the Spitzer Space Telescope, are presented. We show the driving source is detected in all 4 IRAC bands, which suggests that traditional Class 0 classification, although essentially correct, needs to accommodate the new high sensitivity infrared arrays and their ability to detected deeply embedded sources. The IRAC, MIPS 24 and 70 microns new photometric points are consistent with a spectral energy distribution dominated by a cold, dense envelope surrounding the protostar. The Cep E outflow, unlike its more famous cousin the HH 46/47 outflow, displays a very similar morphology in the near and mid-infrared wavelengths, and is detected at 24 microns. The interface between the dense molecular gas (where Cep E lies) and less dense interstellar medium, is well traced by the emission at 8 and 24 microns, and is one of the most exotic features of the new IRAC and MIPS images. IRS observations of the North lobe of the flow confirm that most of the emission is due to the excitation of pure H2 rotational transitions arising from a relatively cold (Tex~700 K) and dense (N{H}~9.6E20 cm-2 molecular gas.Comment: 14 pages (pre-print format), including 6 figures. Published in ApJ Special Spitzer Issue (2004

Causality in Political Networks

As the study of political networks becomes more common in political science, greater attention to questions of causality is warranted. This essay explores competing visions of causality in political networks. Independent essays address issues of statistical model specification, identification of multi-step personal influence, measurement error, causality in historical perspective, and the insights of field experiments. These essays do not agree entirely on the nature of causality in political networks, though they commonly take seriously concerns regarding homophily, time- consistency, and the uniqueness of political network data. Serious consideration of these methodological issues promises to enhance the value-added of network analysis in the study of politics