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Air Force Institute of Technology

Biological and Chemical Physics

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Full-Text Articles in Physics

Reinvigorating A Technical Countering Weapons Of Mass Destruction Distance Learning Graduate Certificate Program, James C. Petrosky, Gaiven Varshney, Jeremy Slagley, Sara Shaghaghi Oct 2021

Reinvigorating A Technical Countering Weapons Of Mass Destruction Distance Learning Graduate Certificate Program, James C. Petrosky, Gaiven Varshney, Jeremy Slagley, Sara Shaghaghi

Faculty Publications

Current Countering Weapons of Mass Destruction (CWMD) demands can be divided broadly into policy and science. The science of chemical, biological, and radiological/nuclear weapons informs the limits of development, production, employment, operation, detection, risk characterization, human and material protection, and medical intervention. In short, the science of weapons of mass destruction (WMD) should precede and inform the development of policy. It is to this end that the Air Force Institute of Technology (AFIT) CWMD program was re-established, providing a technical educational option for practitioners to understand the science behind a very technically challenging subject.

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Reference Dependence Of The Two-Determinant Coupled-Cluster Method For Triplet And Open-Shell Singlet States Of Biradical Molecules, Jesse J. Lutz, Marcel Nooijen, Ajith Perera, Rodney J. Bartlett Apr 2018

Reference Dependence Of The Two-Determinant Coupled-Cluster Method For Triplet And Open-Shell Singlet States Of Biradical Molecules, Jesse J. Lutz, Marcel Nooijen, Ajith Perera, Rodney J. Bartlett

Faculty Publications

We study the performance of the two-determinant (TD) coupled-cluster (CC) method which, unlike conventional ground-state single-reference (SR) CC methods, can, in principle, provide a naturally spin-adapted treatment of the lowest-lying open-shell singlet (OSS) and triplet electronic states. Various choices for the TD-CC reference orbitals are considered, including those generated by the multi-configurational self-consistent field method. Comparisons are made with the results of high-level SR-CC, equation-of-motion (EOM) CC, and multi-reference EOM calculations performed on a large test set of over 100 molecules with low-lying OSS states. It is shown that in cases where the EOMCC reference function is poorly described, TD-CC …

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Characterization Of Neutron And Proton Exposure On The Radiation Resistant Bacterium, Deinococcus Radiodurans, Ronald C. Lenker Mar 2017

Characterization Of Neutron And Proton Exposure On The Radiation Resistant Bacterium, Deinococcus Radiodurans, Ronald C. Lenker

Theses and Dissertations

Deinococcus radiodurans is a robust bacterium that is known for its extraordinary resistance to ionizing radiation. In general, many of the investigations of this bacterium's resistance have revolved around low linear energy transfer radiation, such as gamma and electron radiation. This study explored Deinococcus radiodurans's ability to survive high linear energy transfer radiation, specifically proton and neutron radiation. Deinococcus radiodurans was dehydrated to reduce the effects of low linear energy transfer radiation. The bacteria were exposed to both neutron and proton radiation of varying amounts and rehydrated. The resulting colonies were counted and compared to colonies of non-irradiated control samples …

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Combating Biological Terrorism From Imported Food, Jeffrey S. Nelson Mar 2011

Combating Biological Terrorism From Imported Food, Jeffrey S. Nelson

Theses and Dissertations

There is a threat that a terrorist or terrorist organization will use access to the US food supply to kill or sicken Americans by contaminating imported food products from Mexico. The food that Americans eat is coming more and more often from foreign countries such as Mexico. Foodborne diseases infect nearly fifty million people in the US each year, resulting in over three thousand deaths. There are many terrorist organizations that would like to deliberately contaminate American food. Drug cartels and terrorist organizations currently operate in Mexico, one of the leading food importers into the US. The purpose of this …

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Modeling Of Bacillus Spores: Inactivation And Outgrowth, Alexis X. Hurst Mar 2011

Modeling Of Bacillus Spores: Inactivation And Outgrowth, Alexis X. Hurst

Theses and Dissertations

This research models and analyzes the thermochemical damage produced in Bacillus spores by short, high-temperature exposures as well the repair process within damaged Bacillus spores. Thermochemical damage in spores is significantly due to reaction with water, hydrolysis reactions. Applying heat to the spore causes absorbed and chemically bound water molecules become mobile within the spore. These mobile water molecules react by hydrolysis reactions to degrade DNA and enzyme molecules in the spore. In order to survive the thermal inactivation, the spore must repair the damaged DNA during spore germination. The DNA repair process, as well as other germination functions, is …

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Thermal Inactivation Of Bacillus Anthracis Using Laser Irradiation Of Micro-Etched Platforms, Jeffrey B. Bacon Mar 2009

Thermal Inactivation Of Bacillus Anthracis Using Laser Irradiation Of Micro-Etched Platforms, Jeffrey B. Bacon

Theses and Dissertations

The purpose of this research was to determine the probability of kill for a thermal inactivation strategy for use against biological agents; specifically the resilient endospore of Bacillus anthracis (Ba). The effort focused on short durations (milliseconds to several seconds) and temperatures (300 to 1300 K) simulating the periphery effects after an explosion generated by conventional munitions. For an improved statistical counting, applied microlithography techniques were used to produce micro-etched glass platforms consisting of 532 circular sample wells, evenly spaced. Small carbon black radiators, which provide fast heating/cooling rate and confined temperature distribution, were produced by populating the etched wells …

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In Vitro Toxicity Of Silver Nanoparticles In Human Lung Epithelial Cells, Christina R. Kearns Mar 2009

In Vitro Toxicity Of Silver Nanoparticles In Human Lung Epithelial Cells, Christina R. Kearns

Theses and Dissertations

Nanotechnology is quickly becoming incorporated into everyday products and uses. Silver nanoparticles, specifically, are being used in commercial products, to include aerosols. The purpose of this research was to determine whether silver nanoparticles are toxic to human lung epithelial cells. Different types (coated vs. uncoated), concentrations (10, 50, 100, and 200 µg/mL) and sizes (coated 5 and 80nm, uncoated 10 and 80nm) of silver nanoparticles were used during this study. Toxicity measurements were completed through in vitro techniques. Another study was also completed on toxicity mechanisms by measuring the reactive oxygen species (ROS) generated. Results showed that silver nanoparticles induce …

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Detection Of Bacillus Spores By Aptamer Selectivity Using Atomic Force Microscopy, Nina M. Houtkooper Mar 2005

Detection Of Bacillus Spores By Aptamer Selectivity Using Atomic Force Microscopy, Nina M. Houtkooper

Theses and Dissertations

The anthrax attack of Oct 2001 demonstrates the need for a rapid detector for spores of Bacillus anthracis (BA). Current technology requires cultures of BA to be grown for 24 hours. Using aptamers, a type of nucleic acid ligand selective for a target molecule, to select BA spores for measurement without culturing is a possible solution for quicker detection. An aptamer having a specially selected structure is expected to selectively bind to the surface of its target spore, separating it from other material. An atomic force microscopy (AFM) method was developed to test this selectivity. Aptamers having structure selected to …

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Lethality Of Bacillus Anthracis Spores Due To Short Duration Heating Measured Using Infrared Spectroscopy, Kristina M. Goetz Mar 2005

Lethality Of Bacillus Anthracis Spores Due To Short Duration Heating Measured Using Infrared Spectroscopy, Kristina M. Goetz

Theses and Dissertations

There are a number of analytical and semi-empirical models that describe the behavior of particulate matter in the atmosphere. Many of these require modification for all types of weather, dry versus wet deposition, and overall effects can be quite non-linear. Rainfall (rate, drop size, etc.), snowfall (rate, flake size, etc.), humidity, pressure, temperature, and combination of these greatly affect particle settling and washout rates. To that end, a method for tracking released constituents using the Regional Atmospheric Modeling System (RAMS) microphysics package is developed by modifying one of the hydrometeor categories (hail) in the microphysics package. The RAMS microphysics package …

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Collisional Dynamics Of Bi2 A(0U+). I. Quantum-Resolved Vibrational Energy Transfer For V′=0–4, Robert E. Franklin, Glen P. Perram Oct 1999

Collisional Dynamics Of Bi2 A(0U+). I. Quantum-Resolved Vibrational Energy Transfer For V′=0–4, Robert E. Franklin, Glen P. Perram

Faculty Publications

Vibrational-to-translational energy transfer between the lowest vibrational levels (v′=0–4) of the A(0+u) state of Bi2 has been investigated using spectrally resolved, laser-induced fluorescence techniques. The small vibrational spacing (ω′e≃132 cm−1) leads to highly nonadiabatic conditions, particularly for the Bi2(A)–He collision pair. However, the Δv=−1 transition probabilities for collisions with the rare gases range from 0.75% to 1.75% per collision, considerably lower than would be anticipated from standard vibrational energy transfer theory. Multiquantum (Δv′=±2) transfer rates are low, consistent with the low anharmonicity of the A(0+u) state. The rates for …

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