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Wildfire Impacts on Water Quality and Implications for Disinfection Byproduct Formation
No full textForested watersheds are used worldwide as sources of high-quality drinking water. These areas have coevolved with wildfire, but climate change-induced increases in temperature and drought, plus mismanagement of forested areas are increasing the frequency and severity of wildfires. These can have adverse effects on drinking water quality by destroying vegetation, altering hydrologic regimes, and increasing erosion and nutrient loading into surface water. Another aspect of wildfire is the alteration of organic matter. Fire is known to increase the aromaticity of dissolved organic matter (DOM) and decrease its molecular weight. This affects various aspects of water treatment, including disinfection. The addition of disinfectants, such as chlorine, to water containing wildfire-affected DOM has been shown to increase concentrations of the regulated disinfection byproducts (DBPs) known as trihalomethanes (THMs) and haloacetic acids (HAAs), though questions remain about changes in the reactivity of fire-affected DOM to form these. Less attention has been paid to unregulated nitrogenous DBPs (N-DBPs), such as haloacetonitriles (HANs), and currently, no studies have investigated the effect of wildfire on haloacetamide (HAM) formation. This warrants further investigation to inform water utilities so that they may better treat these waters and protect public health.The aims of this dissertation were to 1) understand watershed-scale impacts of wildfire on water quality and DBP precursor loading in mountain streams and rivers during storm flushes and winter, spring, summer, and fall flow regimes, 2) investigate the effect of both oxygen concentration and temperature on DBP precursor transformation in soil, and 3) understand the effect of soil heating on DOM hydrophobicity, molecular weight, and the relation to DBP precursor reactivity. Watershed scale impairment of water quality and DOM changes caused by wildfire were confirmed at the bench scale. Wildfire and simulated wildfire conditions cause changes in the reactivity of DOM to form C- and N-DBPs. To identify the DOM fractions responsible for these changes, hydrophilic and hydrophobic DOM fractions were isolated to study their changes in DBP formation potential, optical properties, and molecular weight distribution after thermal alteration. Conclusions from this research may aid in tailoring treatment for improving public health and meeting regulatory requirements
Investigating population status, habitat, and ecological interactions for the Sand Mountain blue butterfly, one of North America's most geographically restricted butterflies
Get PDFEuphilotes pallescens arenamontana, the Sand Mountain blue butterfly, is a subspecies of the pallid blue and is endemic to Sand Mountain, a dune system in central Nevada, USA. Eriogonum nummulare, Kearney's buckwheat, is the larval host plant and primary nectar resource and can be found bordering the western edge of the dune system as well as in isolated pockets on the eastern side of the dunes. The butterfly is of conservation concern due to its small geographic range (a single locality) and restricted habitat association as well as recreational activities at Sand Mountain. Motivated by the rarity of the butterfly and associated concerns, we ask the following questions: 1) is the E. p. arenamontana population stable across years? 2) are there habitat features that predict the presence and abundance of caterpillar and adult life stages? 3) to what extent has the vegetation composition changed over the years at Sand Mountain? and 4) which insects at Sand Mountain are using and potentially pollinating E. nummulare? To address the population question, adult butterfly counts were conducted in the years 2006, 2022, and 2023 with meandering surveys at 27 sites along a 3 mile transect from the northeast end to the southwest extent of the dune complex at Sand Mountain. Variables that include the cover of E. nummulare, disturbance, and ant presence were quantified at 67 plots and used to examine habitat association for caterpillars and adult butterflies. A slight decline is apparent in the weekly average of butterflies seen between 2006 and the more recent years of 2022 and 2023. The best predictors for caterpillar presence in a plot are inflorescences of Kearney's buckwheat, the abundance of ants, and the total numbers of adult butterflies, while precent cover of the focal plant in a plot is the best predictor of adult butterfly presence. Vegetation composition appears to have changed over the years, comparing 2006 and 2024, with fewer E. nummulare plants and the presence of new plants including nonnative and invasive Bromus tectorum. Insects in the order Hymenoptera were found to be carrying the most E. nummulare pollen, and within that order the family Crabronidae was associated with the highest densities of pollen. We use these results to assess the conservation status of E. p. arenamontana and to consider whether additional protections are needed for this rare butterfly, its host plant, and mutualist ant partners
Challenging the Authoritarian Theory of the Press: Mostafa Amin and Press Freedom Under King Farouk's Rule in Egypt
Get PDFThis thesis examines the authoritarian theory of the press coined by Siebert et al. (1956), which proposes a strict control over the press, and its applicability on monarchical Egypt. It challenges the rigid categorization by presenting a case study of a famous Egyptian journalist Mostafa Amin and the ways in which he navigated the ostensible authoritarian rule of King Farouk, who ruled from 1936 to 1952. The thesis states that the authoritarian theory of the press can't be applied in every country or under every authoritarian regime, as Farouk's regime portrayed several libertarian themes. Moreover, the one-way linear progression of press systems that Siebert et al. predicted is also proven to be flawed as after Farouk, Egypt had a complete authoritarian rule under Nasser
Enhancing Tribological Performance of Engineered Plastic Oil with Solid Lubricant Additives
Get PDFPlastics are widely used in various applications due to their light weight, ease of production, and low cost. Despite their widespread usage, they have significant drawback of being non-biodegradable. If not disposed off appropriately, they cause extensive environmental pollution, posing health risks to living beings. To mitigate this issue, plastics can be recycled, and through chemical techniques, can be converted into useful products such as waste plastic oil (PO) lubricant. In this work, the lubrication performance of the PO was investigated. To further improve the lubrication performance, solid lubricant additives (SLAs) of graphene nano platelets (GNP), and hexagonal boron nitride (hBN), were separately added to the PO, forming nano lubricants. The incorporated SLAs suffered from sedimentation and inadequate dispersion stability. To address these issues, and further enhance the lubrication performance of the PO, an oleic acid surfactant based chemical functionalization process was carried out on the SLAs. The impact of functionalization on the lubricant's rheological properties, thermal degradation resistance, dispersion stability, friction, and wear performances were evaluated. The significant insights gained from this study can help boost the lubrication performance of the PO, lower dependence on virgin petroleum-based products, reduce environmental pollution, and promote its broader adoption in industrial applications
Tongue Pressures in Healthy Adults Aged Sixty to Seventy-Nine
Get PDFBackground: Tongue pressure is essential to normal tongue function. Tongue pressure influences mastication and swallowing. Aim: The study investigated the tongue pressure of healthy, English-speaking individuals aged 60 to 79 in the United States to establish an anterior and posterior tongue pressure database. The study examined sex differences in tongue pressure. In addition, the study established an anterior-to-posterior tongue pressure ratio. Population: Fifty healthy adults aged 60-79, balanced by sex (25 males; M = 67.48, SD = 5.01, 25 females; M = 67.84, SD = 5.29). Method: The Iowa Oral Performance Instrument was used to measure anterior and posterior maximum isometric tongue pressure and to establish an average anterior-to-posterior tongue pressure ratio based on maximum isometric pressure. Results: Statistical analyses included descriptive statistics, paired t-tests, and a linear regression. The mean MIP for the anterior is 46.48 kPa ( SD = 10.51) and for the posterior is 48.60 kPa ( SD = 10.49). Results revealed no statistically significant difference between anterior and posterior maximum isometric pressures ( p = 0.08) or between sexes for anterior ( p = 0.38) or posterior ( p = 0.70) maximum isometric pressures. A linear regression revealed a positive correlation between anterior and posterior tongue pressures per participant ( R 2 = 0.97). The average anterior-to-posterior tongue pressure ratio is .98 kPa ( SD =.17). A two-tailed t-test yielded no statistical difference in the APTR by sex ( p = 0.32)
Cracking Performance Evaluation of Asphalt Mixtures in Virginia
Get PDFAsphalt plays an essential role in various transportation and infrastructure projects worldwide. Throughout its production and service life, asphalt binder undergoes aging influenced by factors like temperature and exposure to oxygen. Oxidative aging, for instance, alters the properties of the asphalt binder, leading to increased stiffness and a consequent decrease in resistance to cracking. This study aims to establish a long-term aging protocol specifically tailored for evaluating the cracking resistance of asphalt mixtures in Virginia. The research comprised two phases. The first phase focuses on establishing a practical aging protocol for dense-graded surface mixtures (SM) A and D that can be implemented in mix design and acceptance. According to Virginia Department of Transportation (VDOT), the A designation corresponds to mixtures with an equivalent single axle load (ESAL) of 0 to 3 million while the D designation corresponds to an ESAL range of 3 to 10 million. The second phase aims to establish initial test criteria for the CT index based on the current criteria for short-term aged asphalt mixtures. Given the challenges with aging of compacted specimens (e.g., aging gradient within the specimen), loose asphalt mixture aging was employed in this study. Eleven SMs from Virginia were selected, each comprising different combinations of reclaimed asphalt pavement (RAP), asphalt binder grade and content, aggregate gradation, and recycling agent (RA). Preliminary observations from 3 of the 11 SMs suggest a critical aging duration of 1 day at 95°C following 4 hours of aging at compaction temperature (4H_1D). This aging level demonstrates the ability to differentiate between the cracking resistance of the evaluated asphalt mixtures. Equivalent accelerated aging durations of 6 and 8 hours at compaction temperature (6H_0D, 8H_0D) were evaluated and found to simulate the 4H_1D aging duration. To set the criteria for CTindex at the critical aging found in the study, a thorough analysis of the test data was done. This analysis involved a combination of test parameters obtained from the different binder and mixture testing. Glover-Rowe parameter (GRP) was plotted against the CTindex for all mixtures and the cracking limits were obtained in terms of CTindex limits. Additionally, the CTindex was plotted against the aging duration and the cracking limits were also found in terms of aging duration. The resulting CTindex limits for cracking were about 71 for an onset of cracking corresponding to a GRP of 180 kPa and 43 for significant cracking corresponding to a GRP of 600 kPa. Furthermore, the aging durations for cracking were 0.26 days (4 hrs at compaction temperature followed by 2.24 hrs at 95C) for onset of cracking (i.e., GRP equal to 180 kPa) and 1.41 days (4 hrs at compaction temperature followed by 29.84 hrs at 95C) for significant cracking (i.e., GRP equal to 600 kPa). The drop in CTindex after 4 hours of aging was calculated for each aging level and was found to have a strong correlation with the GRP of the recovered asphalt binder from the asphalt mixture at the respective aging level. A 10.8% drop in CTindex after 4 hours of aging corresponds to the asphalt binder onset of cracking (GRP of 180 kPa) and a further drop reaching 29.8% corresponds to the significant cracking level (GRP of 600 kPa). These preliminary findings will be verified in a follow up study using the remaining 8 SMs from Virginia
Zeroing in on Reducing Gun and Violent Crime
Get PDFFrom 2013 to 2017, the City of Reno experienced significant increases in gun and violent crime that impeded the safety of the community. The RPD obtained funding through a grant to reduce gun and violent crime by utilizing four intervention strategies: focused deterrence, hot spot policing, crime prevention through environmental design, and community outreach. This thesis examines and evaluates the intervention strategies implemented at specific geographic locations in Reno that experienced disproportionately higher levels of violence and gun crime. The results of this study provide partial support for the effectiveness of the intervention strategies. These findings are further contextualized in the discussion section with an emphasis on the implications for other law enforcement agencies looking to adopt similar evidence-based policing strategies in their cities
How to Grieve
No full textHow to Grieve is a short story collection of approximately 69,200 words. The nineteen stories cover themes of friendship, grief, and men's violence
Privacy and Security for Trustworthy AI/ML in Multi-Agent Critical Infrastructures: An Analysis of Adversarial Dynamics and Protective Strategies
Get PDFThis dissertation analyzes the pressing security and privacy challenges in Multi-Agent Critical Infrastructures ( MACIs ), which increasingly integrate cyber-physical system components like IoT devices, sensors, UAVs, and cloud technologies. These components are prolific data generators and are crucial for operational efficacy and enhanced decision-making across various artificial intelligence (AI) and machine learning (ML)�" driven MACI sectors. However, the integration of state-of-the-art AI/ML techniques in MACIs, although beneficial for predictive analytics and decision support, introduces significant vulnerabilities to sophisticated cyberattacks. The raw MACI data�"serving as the training data for these AI/ML frameworks�"often contain sensitive user and operational information, necessitating robust privacy and security measures to protect against unauthorized access and manipulation. Thus, there is a growing need for robust data privacy and security methods to be integrated into the information-sharing and learning process of these frameworks in order to preserve data confidentiality and authenticity. In this context, this dissertation analyzes the inherent vulnerabilities and threats to existing information exchange and techniques as well as their exploitation and impacts on the disclosure of private information and MACI operations. Central to our analysis is the scrutiny of differential privacy (DP), a prevalent method for safeguarding data privacy, which we find is susceptible to adversarial exploitation. Our analysis reveals that DP paradoxically introduces exploitable loopholes that adversaries can leverage to conduct stealthy attacks such as false data injection and poisoning in various learning frameworks including federated learning ( FL ) and cooperative multi-agent reinforcement learning ( CMARL ). To address these threats, the dissertation presents a comprehensive theoretical analysis from an adversarial perspective, developing a novel analytical framework that establishes a provable correlation between DP parameters and adversarial objectives to aid in designing robust, fault-tolerant systems. Particularly, we present novel adversarial strategies like differential privacy-exploited stealthy model poisoning (DeSMP) attacks in FL. Further investigation in this direction led us to develop an adaptive model poisoning through episodic loss memorization (α-MPELM) technique, which deceives state-of-the-art Norm , Accuracy , and Mix ( Norm + Accuracy ) anomaly detection algorithms by 6.8%, 12.6%, and 13.8%, respectively. In response to these challenges, we introduce a reinforcement learning (RL)-based DP level selection strategy, termed rDP, which dynamically adjusts the necessary level of DP noise�"small enough to keep the poisoning window tolerable; yet large enough to maintain a satisfactory level of data privacy. Addressing localized poisoning in CMARL, the dissertation proposes the privacy-exploited local poisoning attack (PeLPA), which exploits DP noise to hinder model convergence effectively, increasing steps to goal by up to 64.41% and prolonging convergence times by 1.38x. As a countermeasure, we developed reinforcing autonomous multi-agent protection through adversarial resistance in transportation (RAMPART), a generative adversarial network (GAN)-based defense mechanism that filters malicious data and generates synthetic samples to maintain model integrity, achieving an F1 score of 0.852 and an accuracy of 96.3%. Moreover, we analyze adversarial manipulation in CMARL's experience-sharing processes, where we introduce the Byzantine robust neighbor experience-sharing (BRNES) framework to mitigate Byzantine attacks through dynamic neighbor selection and weighted experience aggregation. BRNES is faster in response times by up to 8.32x compared to non-private frameworks. This comprehensive analysis of the aforementioned adversarial tactics and the development of several novel defensive measures in this dissertation will enable future researchers and developers to design, deploy, verify, and maintain trustworthy AI/ML frameworks for next-generation MACI operations. Additionally, it will benefit them to conduct further research and development to mitigate unprecedented and time-constrained adversarial techniques through neuroadaptive modeling, continual learning, and secured neurocognitive information exchange