Characterization and Modeling of High Power Microwave Effects in CMOS Microelectronics

The intentional use of high power microwave (HPM) signals to disrupt microelectronic systems is a substantial threat to vital infrastructure. Conventional methods to assess HPM threats involve empirical testing of electronic equipment, which provides no insight into fundamental mechanisms of HPM induced upset. The work presented in this dissertation is part of a broad effort to develop more effective means for HPM threat assessment. Comprehensive experimental evaluation of CMOS digital electronics was performed to provide critical information of the elementary mechanisms that govern the dynamics of HPM effects. Results show that electrostatic discharge (ESD) protection devices play a significant role in the behavior of circuits irradiated by HPM pulses. The PN junctions of the ESD protection devices distort HPM waveforms producing DC voltages at the input of the core logic elements, which produces output bit errors and abnormal circuit power dissipation. The dynamic capacitance of these devices combines with linear parasitic elements to create resonant structures that produce nonlinear circuit dynamics such as spurious oscillations. The insight into the fundamental mechanisms this research has revealed will contribute substantially to the broader effort aimed at identifying and mitigating susceptibilities in critical systems. Also presented in this work is a modeling technique based on scalable analytical circuit models that accounts for the non-quasi-static behavior of the ESD protection PN junctions. The results of circuit simulations employing these device models are in excellent agreement with experimental measurements, and are capable of predicting the threshold of effect for HPM driven non-linear circuit dynamics. For the first time, a deterministic method of evaluating HPM effects based on physical, scalable device parameters has been demonstrated. The modeling presented in this dissertation can be easily integrated into design cycles and will greatly aid the development of electronic systems with improved HPM immunity

Creative Writing Research Benchmark Statement

The benchmark guidance for Creative Writing research from the National Association of Writers in Education, the subject association for creative writing

EMITTANCE MEASUREMENTS OF THE JEFFERSON LAB FREE ELECTRON LASER USING OPTICAL TRANSTION RADIATION

Charged particle accelerators, such as the ones that power Free Electron Lasers (FEL), require high quality (low emittance) beams for efficient operation. Accurate and reliable beam diagnostics are essential to monitoring beam parameters in order to maintain a high quality beam. Optical Transition Radiation Interferometry (OTRI) has shown potential to be a quality diagnostic that is especially useful for high brightness electron beams such as Jefferson Labs FEL energy recovery linac. The purpose of this project is to further develop OTRI beam diagnostic techniques. An optical system was designed to make beam size and divergence measurements as well as to prepare for experiments in optical phase space mapping. Beam size and beam divergence measurements were taken to calculate the emittance of the Jefferson Lab FEL. OTRI is also used to separate core and halo beam divergences in order to estimate core and halo emittance separately

The compositional and configurational heterogeneity of matrix habitats shape woodland carabid communities in wooded-agricultural landscapes

Landscape heterogeneity (the composition and configuration of matrix habitats) plays a major role in shaping species communities in wooded-agricultural landscapes. However, few studies consider the influence of different types of semi-natural and linear habitats in the matrix, despite their known ecological value for biodiversity. Objective To investigate the importance of the composition and configuration of matrix habitats for woodland carabid communities and identify whether specific landscape features can help to maintain long-term populations in wooded-agricultural environments. Methods Carabids were sampled from woodlands in 36 tetrads of 4 km2 across southern Britain. Landscape heterogeneity including an innovative representation of linear habitats was quantified for each tetrad. Carabid community response was analysed using ordination methods combined with variation partitioning and additional response trait analyses. Results Woodland carabid community response was trait-specific and better explained by simultaneously considering the composition and configuration of matrix habitats. Semi-natural and linear features provided significant refuge habitat and functional connectivity. Mature hedgerows were essential for slow-dispersing carabids in fragmented landscapes. Species commonly associated with heathland were correlated with inland water and woodland patches despite widespread heathland conversion to agricultural land, suggesting that species may persist for some decades when elements representative of the original habitat are retained following landscape modification. Conclusions Semi-natural and linear habitats have high biodiversity value. Landowners should identify features that can provide additional resources or functional connectivity for species relative to other habitat types in the landscape matrix. Agri-environment options should consider landscape heterogeneity to identify the most efficacious changes for biodiversity

Climate change: challenges and opportunities for global health.

IMPORTANCE: Health is inextricably linked to climate change. It is important for clinicians to understand this relationship in order to discuss associated health risks with their patients and to inform public policy. OBJECTIVES: To provide new US-based temperature projections from downscaled climate modeling and to review recent studies on health risks related to climate change and the cobenefits of efforts to mitigate greenhouse gas emissions. DATA SOURCES, STUDY SELECTION, AND DATA SYNTHESIS: We searched PubMed and Google Scholar from 2009 to 2014 for articles related to climate change and health, focused on governmental reports, predictive models, and empirical epidemiological studies. Of the more than 250 abstracts reviewed, 56 articles were selected. In addition, we analyzed climate data averaged over 13 climate models and based future projections on downscaled probability distributions of the daily maximum temperature for 2046-2065. We also compared maximum daily 8-hour average ozone with air temperature data taken from the National Oceanic and Atmospheric Administration, National Climate Data Center. RESULTS: By 2050, many US cities may experience more frequent extreme heat days. For example, New York and Milwaukee may have 3 times their current average number of days hotter than 32°C (90°F). High temperatures are also strongly associated with ozone exceedance days, for example, in Chicago, Illinois. The adverse health aspects related to climate change may include heat-related disorders, such as heat stress and economic consequences of reduced work capacity; respiratory disorders, including those exacerbated by air pollution and aeroallergens, such as asthma; infectious diseases, including vectorborne diseases and waterborne diseases, such as childhood gastrointestinal diseases; food insecurity, including reduced crop yields and an increase in plant diseases; and mental health disorders, such as posttraumatic stress disorder and depression, that are associated with natural disasters. Substantial health and economic cobenefits could be associated with reductions in fossil fuel combustion. For example, greenhouse gas emission policies may yield net economic benefit, with health benefits from air quality improvements potentially offsetting the cost of US and international carbon policies. CONCLUSIONS AND RELEVANCE: Evidence over the past 20 years indicates that climate change can be associated with adverse health outcomes. Health care professionals have an important role in understanding and communicating the related potential health concerns and the cobenefits from policies to reduce greenhouse gas emissions

Implementing Prenatal Diagnosis Based on Cell-Free Fetal DNA: Accurate Identification of Factors Affecting Fetal DNA Yield

Objective: Cell-free fetal DNA is a source of fetal genetic material that can be used for non-invasive prenatal diagnosis. Usually constituting less than 10% of the total cell free DNA in maternal plasma, the majority is maternal in origin. Optimizing conditions for maximizing yield of cell-free fetal DNA will be crucial for effective implementation of testing. We explore factors influencing yield of fetal DNA from maternal blood samples, including assessment of collection tubes containing cell-stabilizing agents, storage temperature, interval to sample processing and DNA extraction method used.Methods: Microfluidic digital PCR was performed to precisely quantify male (fetal) DNA, total DNA and long DNA fragments (indicative of maternal cellular DNA). Real-time qPCR was used to assay for the presence of male SRY signal in samples.Results: Total cell-free DNA quantity increased significantly with time in samples stored in K(3)EDTA tubes, but only minimally in cell stabilizing tubes. This increase was solely due to the presence of additional long fragment DNA, with no change in quantity of fetal or short DNA, resulting in a significant decrease in proportion of cell-free fetal DNA over time. Storage at 4 degrees C did not prevent these changes.Conclusion: When samples can be processed within eight hours of blood draw, K(3)EDTA tubes can be used. Prolonged transfer times in K(3)EDTA tubes should be avoided as the proportion of fetal DNA present decreases significantly; in these situations the use of cell stabilising tubes is preferable. The DNA extraction kit used may influence success rate of diagnostic tests

Motivating compliance: Juvenile probation officer strategies and skills

Juvenile probation officers aim to improve youth compliance with probation conditions, but questions remain about how officers motivate youth. The study’s purpose was to determine which officer-reported probation strategies (client-centered vs. confrontational) were associated with their use of evidence-based motivational interviewing skills. Officers (N = 221) from 18 Indiana counties demonstrated motivational interviewing skills by responding to scenarios depicting issues common to youth probationers. Results of a hierarchical multiple regression analysis indicated that, while officer endorsement of client-centered strategies was not associated with differential use of motivational interviewing skills, officers endorsing confrontational strategies were less likely to demonstrate motivational interviewing skills