The dissertation thesis deals with the development of the Laser-Induced Breakdown Spectroscopy (LIBS) setup in the modification for the mobile remote material analysis (so called rLIBS). The experimental device is developed at the Institute of Physical Engineering, Faculty of Mechanical Engineering (FME), Brno University of Technology (BUT). Such a modification is possible due to the core principles of LIBS technique, i.e. using a laser for a sample excitation and plasma radiation for spectral analysis. The thesis is focused on the variation called Stand-Off LIBS with the target analyte in the distance of 6 meters. In this case the laser pulse and the plasma radiation are transmitted through the local environment (usually the air) and the direct device-to-sample visibility is expected. The motivation for this development is to avoid traditional processes of sample collection, preparation and transport that are time-consuming, expensive and sometimes even hard to realize. Stand-Off LIBS allows bringing all the LIBS technique benefits from the laboratory to the field, where fast, in-situ analysis can be carried out. The first part of the thesis focuses on the history and principles of the Atomic Emission Spectroscopy (AES), as it is the main principle of LIBS technique. The second part describes the history, theory, instrumentation and applications of LIBS as a modern analytical tool. This part also introduces the remote mobile modification – rLIBS, as well as the current state of knowledge and the state of the development in LIBS laboratories worldwide. The third part describes the individual stages of the rLIBS development at the Institute of Physical Engineering, FME BUT. This chapter details the focusing optics design, building of the collection optics, design and construction of the detection unit, motorized stage and mobile track. This section contains also the results of the test spectroscopy measurements and movement ability measurements.

京都大学 / 0048 / 新制・論文博士 / 博士(農学) / 乙第13181号 / 論農博第2860号 / 新制||農||1061(附属図書館) / 学位論文||H30||N5103(農学部図書室) / (主査)教授 小杉 緑子, 教授 北山 兼弘, 教授 舟川 晋也 / 学位規則第4条第2項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

With a growing desire to generate structural characteristics of late-successional conifer forests, managers are commonly seeking an approach to increase structural heterogeneity in otherwise simple second-growth stands. This study examined understory response to experimental thinning on the Olympic Peninsula of Western Washington. Variable-density thinning within the Olympic Habitat Development Study was found to have significant effects on both the density of seedling recruitment as well as early growth of western hemlock (Tsuga heterophylla (Raf.) Sarg.). In additional analysis, pre-commercial understory thinning, implemented by the Olympic National Forest, produced no observable acceleration in basal area growth. Results suggest that understory development is sensitive to previous management history as well as post-treatment stand structure. Better understanding the sources of variability in understory tree response to non-uniform thinning and understory density management will be principle in evaluating the efficacy of these treatments relative to traditional methods.

The Institute of Clean Energy Technology (ICET) at Mississippi State University was awarded a contract by the DOE to design, fabricate, assemble, and characterize a research grade test stand to assist in the development of ASME AG-1 Section FI Metal Media Filters. The major barriers to completing the code section is development of a test stand for collecting data necessary to specify performance requirements for use and for filter qualification. Currently there is not a test stand capable of performing this testing. Performance criteria for the FI test stand were developed by the Section FI project team and ICET. These performance criteria were used to create a test stand to collect the data necessary to get Section FI balloted and approved.

Switchgrass (Panicum virgatum), a high-yielding perennial C4 prairie grass species, is a top candidate as a bioenergy feedstock for cellulosic ethanol production. Seedling establishment is a primary concern given the inherent variability in switchgrass seed dormancy. Determining current states of seed quality in terms of emergence percentage is crucial for a successful stand establishment. A practical seed vigor test was conducted under greenhouse conditions to determine current emergence percentage. Three depths and three media types were conditions evaluated in the vigor test. To find correlation between emergence percentage in greenhouse test conditions and that in field conditions, results from the vigor test were applied in two separate field evaluations. Field evaluations showed that vigor test conditions of field soil at 1-cm depth yielded below the target, suggesting that this condition did not put enough stress on seedling emergence in the greenhouse vigor test. A 20% increase of vigor test results in the field soil/1 cm condition could accurately predict field emergence. Field results suggested that coarse sand at 5-cm accurately predicted field emergence of highly vigorous varieties and that coarse sand at 1-cm and fine sand at 3-cm predicted field emergence in moderately to least vigorous varieties.

Thesis advisor: Arthur Lewbel / This dissertation consists of three related chapters. A unifying feature throughout all is a focus on the issues in the economics of crime, specifically in how different factors affect different types of index crimes. The first chapter, a collaboration with Abby Hong, examines the role of the stand-your-ground law in driving first-degree and second-degree murder rates. The second chapter, a collaboration with Benjamin Ferri, examines how the two ends of the income distribution impact emotional gain crime and financial gain crime. Both chapters one and two examine how different variables affect crime, and both have a theoretical part and an empirical part. The third chapter looks into measurement issues in crime. Specifically, it considers the impact of a change in data collection methods on the Uniform Crime Report (UCR). The first chapter, “Self-defense Regulations and Crime: Evidence from the Stand Your Ground Law,” provides a theoretical model of crime escalation when governments relax self-defense regulations. We then test the model with an empirical analysis of the “stand-your-ground” (SYG) laws’ impact on planned and unplanned murders. The game theoretical model shows that relaxing self-defense regulations can increase the arming of crime victims. It also increases the arming of offenders in crimes that lead to unplanned murders. If planned murder offenders are over-confident, then their level of arms increases as well. We then use a difference-in-differences (DiD) model to test these implications. We find that consistent with the model, SYG laws in the US increase the planned murder rate by 7.6% and the unplanned murder rate by 10.4%, on average. Also, the effect size increases over time, highlighting the persistence of the impact. The paper illustrates how interactions between victims and offenders result in unintended consequences of self-defense regulations. It also encourages policymakers to take into account criminal behavior when making policy decisions. The second chapter, “The Distinct Roles of Poverty and Higher Earnings in Motivating Crime,” develops a new model that articulates how Poverty (the lower tail of the earnings distribution) and Earnings (the upper tail) enter into equilibrium crime rates. In our model, individuals in Poverty have less to lose in the context of criminal punishment, so are less averse to committing crimes in general. The presence of high Earnings (therefore things worth stealing) heightens the expected gain to offenders per crime - but specifically in terms of financial gain, not emotional gain. We estimate our model on a comprehensive panel of U.S. Commuting Zones (1980-2016), deploying novel Shift-Share instruments to correct for reverse causality (of crime on the earnings distribution). Corroborating our hypothesis, we find that high Earnings plays a much larger role in driving crimes that yield financial gain to the offender (various forms of theft) than it does for crimes of emotional gain; while Poverty is a driving force equally across both types of crime. In each case, not accounting for reverse causality would underestimate both effects, often by more than double. The third and final chapter, “Crime Reporting Standards and Reported Crime,” This paper explores data discrepancies in the Uniform Crime Report (UCR) before and after the adoption and conversion of the National Incident-Based Reporting System (NIBRS). The FBI starts publishing the UCR in 1930 to understand crime trends in the United States. The UCR is published under the Summary Reporting System (SRS) until the 1990s, when the NIBRS is developed to collect more detailed data. The NIBRS is then converted to “synthetic SRS” and concatenated to historical SRS data when it enters the UCR. It uses a staggered event study design based on the year in which the agency switches from the SRS to the NIBRS. I find two factors that contribute to a large and statistically significant increase in reported crime for agencies that adopt the NIBRS compared with agencies that have not: the data conversion process and a change in reporting practices. When I convert the NIBRS to synthetic SRS based on published criteria, I observe a smaller and statistically insignificant increase in assault cases. However, this alternative conversion process does not improve the difference-in-differences (DiD) effects for total crime, murder, robbery, burglary, and theft, highlighting the fact that data from the NIBRS is more complete and more timely. / Thesis (PhD) — Boston College, 2023. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Economics.

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Observations of Bromus tectorum L. (cheatgrass or downy brome) monocultures have shown that populations are susceptible to stand die-off or replacement failures. Die-offs, where the seed bank from the previous year fails to emerge, occurs in cheatgrass stands and it is unclear the trigger or cause. The fungus Fusarium has been identified in plant and seed samples from die-offs and may drive die-off activity through pathogenicity. Die-off recovery may take several years but cheatgrass populations eventually reestablish. The purpose of our study was to determine whether Fusarium is a potential player in a die-off, and understand how die-offs recover after multiple years of stand failure. Our objectives were to determine: 1- litter and water effects on die-off activity; 2- if fungal pathogens, such as Fusarium, decrease the proportion of cheatgrass emergence in a die-off; and 3- whether direct or broadcast seeding, water, and litter treatments increase establishment in recovering die-offs. Litter absent plots had significantly (P < 0.0001 and P < 0.001) more emergence at 49.2% and 41% compared to litter present plots 21.3% and 23.7%. The litter absent plots significantly (P = 0.0003 and P = 0.001) increased survival (82% and 52%) compared to litter present plots (70% and 41%). Direct planted versus broadcast seeding had significantly (P < 0.0001) more emergence, 36% to 11.9%. The addition of Fusarium inoculum to field plots did not effectively replicate anticipated disease levels. The fungicide treatment did not have a significant influence at either site. The results from the study indicate that nothing inhibits cheatgrass from establishing following a persistent die-off disturbance. A unique window may be available for land managers to revegetate natives in invasive populations as large quantities of cheatgrass seeds fail to emerge during die-off events.

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