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A Heuristic Approach to Operations and Control of BTM-DERS for Bill Management and Grid Services
No full textBehind-The-Meter (BTM) distributed energy resources (DERs) have emerged as a critical and transformative force within the energy sector. These decentralized energy assets, which include solar photovoltaic (PV) systems, battery energy storage systems (BESS), and thermostatically controlled loads (TCLs), are increasingly essential for empowering customers by granting them greater control over their energy production and consumption, thereby reducing reliance on centralized power sources. Additionally, they have the potential to play a pivotal role in enhancing grid resilience by providing grid services. This study investigates the management of customer electricity bills and grid services through the integration of various BTM-DERs, particularly solar photovoltaic (PV) systems, BESS, air conditioning systems with smart thermostats, and grid-interactive water heaters, under variable electricity rate. A heuristic optimization approach that leverages the coordinated operation and control of these DERs to minimize customer electricity costs and improve grid services is proposed. Recognizing the potential barrier of high upfront costs for residential customers, this research explores Energy-Storage-as-a-Service (ESaaS) as an alternative to individual BTM-BESSS ownership. Similar to community energy storage (CES), ESaaS provides virtual energy storage through a centralized system located in front of the meter, enabling customers to lease storage capacity. By effectively harnessing photovoltaic power generation, optimizing battery charging and discharging cycles, and strategically scheduling thermostat settings for controllable loads, this approach aims to achieve a balance between maximizing cost savings for customers and enhancing overall grid efficiency and reliability.This work presents practical mathematical models for rooftop photovoltaic (PV) systems, battery storage, air conditioners, and electric water heaters. Day-ahead forecasting techniques were then employed to predict customer generation and consumption profiles, which are crucial for planning DER control strategies. Local weather forecasts from the National Oceanic and Atmospheric Administration (NOAA) and customer smart-meter data were utilized as inputs for these predictions. The study addresses two key factors by formulating optimization functions subject to various constraints: Customer Bill Management (CBM) which aims to minimize the customer\u27s electricity bill under time-of-use electricity pricing which coincides with system Peak Load Management (PLM) as a grid service. To validate the effectiveness of the proposed approach, a case study is presented based on a local residential customer\u27s smart-meter data and appliance power consumption. Customer’s annual electricity bill is evaluated under both flat rate and time-of-use pricing after leasing an ESaaS block are presented to support the efficacy of the proposed approach
Internationally Trained Teachers: Filipinos Working with Children with Disabilities in the U.S.: A Multiple Case Study
No full textThe United States (U.S.) is a major destination for teacher migration, with teachers being hired to fill shortages in math, science, and special education. In fact, the nation’s shortage of special education teachers has hit critical levels, further exacerbated by high levels of attrition. For these reasons, some school districts hire teachers from outside the United States on J-1 visas, including the Philippines.
To ascertain the experiences of special education teachers from the Philippines working in the U.S. on J-1 visas, a multiple case study was conducted. The study was anchored in the transnationalism tenet of AsianCrit, allowing participants to reflect on their classroom and cultural experiences in the U.S. Participants were each analyzed as individual cases before a cross-case analysis examined similarities among cases. The analyses composed of three types of coding: open coding, searching for excerpts from the data that answered the research questions; axial coding, or examining the relationships among codes and assigning them to categories and themes; and selective coding, or tying the themes to the literature. Among the themes that emerged from the analyses were “knowledge of special education” and “different languages” for the in-class experiences and “cultural diversity” and “finances” for the lived experiences outside the classroom.
The current study filled a gap in the existing body of research. No known previous study has ascertained both the experiences of internationally trained special education teachers working outside their home countries and their perspectives of those experiences through the lens of their home culture. Implications for practice and recommendations for future research included cultural awareness for both the participants themselves and people that they work with, and further expansion upon relevant topics
Canine Parasites in Southern Nevada Urban Dog Parks: Paravec Study
No full textWhile dogs are one of humans’ greatest companions, they also serve as hosts for a multitude of parasites. Urban dog parks serve as environments where the transmission of diseases is likely to occur. Exposure to infective agents, contained within the soil, intermediate hosts (e.g., rodents, rabbits), and feces, can directly affect the health of dogs and their owners. Other factors that can further influence canine health include age, previous diagnoses of parasites/diseases, and migration. Many dog owners visit dog parks to encourage socialization and exercise. Such activities are meant to improve health, but unawareness of microbiological organisms can lead to detrimental health conditions if not prevented and treated at the early stages. Human populations, such as children, the elderly, pregnant women, and immunocompromised individuals, who are exposed to certain species of protozoa, helminths, and other parasites, may develop physical and neurological damage. In this study, n = 100 fecal samples from 16 Clark County, NV urban dog parks were collected from canine pets. After laboratory processing using fecal smear and fecal flotation procedures (i.e., sugar and salt), and microscopic observations, we found that canine parasites were present in n=50 (50%) of stool samples. Out of those that were observed, protozoan, nematode, and cestode species were identified, most of which have zoonotic potential. It is important that public health professionals encourage communities to monitor their pets’ health. For instance, appropriate vaccination, routine veterinary checkups, and proper hygienic practices can reduce the risk of transmission
Psychopathy and Moral Decision Making
No full textSince the 1800s, psychopathy has been regarded as the absence of morality. The goal of our study was to explore whether psychopathic traits can affect the moral decision-making process in sacrificial moral dilemmas. Participants completed multiple self-report measures of psychopathic traits, utilitarian tendencies, and 16 sacrificial moral dilemma vignettes. After each hypothetical vignette, participants decided whether they believed it was morally right, permissible, and whether they behaviorally intended to sacrifice one person to save five people. Positive correlations emerged among all variables, which allowed us to perform a mediation analysis. Instrumental Harm – the idea of sacrificing one individual to save a greater number – accounted for more than half of the relationship between Callous Affect traits and ratings of Permissibility and Behavioral Intent. Specifically, the bias corrected indirect effect for permissibility was 0.07 (95% CI [0.01, 0.14]), which represents 54.5% of the total effect. The bias corrected indirect effect for behavioral intent was 0.08 (95% CI [0.01, 0.15]), which represents 53.6% of the total effect. Results indicated that participants high on psychopathic traits find it permissible and had the intent to sacrifice one person to save five. These findings imply that the concept of “moral insanity,” long associated with psychopathy, may not be an accurate representation of this population. Instead, it seems that individuals with Callous Affect psychopathic traits find it more permissible and are more likely to act on behaviors that minimize suffering for the largest amount of people
Developing a Remote Gamma Spectra Collection System for Radiation Sciences at the University of Nevada, Las Vegas
No full textEducational institutions of all levels have been significantly impacted by the COVID-19 epidemic with none more so than higher education. The challenges faced by researchers are numerous while performing a study and have only increased since the pandemic. Many colleges or universities have halted research to cut off unnecessary contact in order to protect study participants and research personnel. In the Department of Health Physics and Diagnostic Sciences (DHPDS) at the University of Nevada Las Vegas, a solution was developed that would allow scientists and students alike to be able to analyze already prepared samples either in the lab or remotely from any computer that the admin allows to access the website. Particularly in cases in which spectra analysis is important such as health physics courses or research observing the composition of samples an automatic sampler can allow for flexibility in the case of being unable to meet for classes or a campus being shut down. This method utilizes a combination of nuclear detection equipment, python coding, a robotic arm, an automatic sampler changer, as well as a VPN to enable professors or researchers to determine who is able to access the results. The process requires samples to be placed in the automatic sample changer capable of holding up to 15 samples, from there a robotic arm transfers the sample into the high-purity germanium detector. A Lynx Digital Signal Analysis (DSA) module is connected to the detector providing analysis on the content of the sample. With a known standard, a calibration curve can be established to identify radioactive isotopes. Although niche automatic samplers already exist in certain fields the costs involved as well as the need for potentially complicated setups they require make them unfeasible for many laboratories; however this paper details the concept and implementation of a cost-effective and user-friendly version
Density-Driven Investigations of Ruthenium Binary Compounds RuX2 (X = O, S, N)
No full textExploration and fine-tuning of the energy landscape of materials can be accessed by means of changes in material density, a key principle of high pressure research. Density-driven changes impact variations in oxidation states and coordination numbers for the element constituents of a compound. Pressure-induced modification of intrinsic density can promote the formation of new materials, variations in physical properties, and transformations in crystallographic symmetry. With this as our foundation, we focus on ruthenium binary compounds - altering the anion species to change electronegativity while probing pressure and temperature effects. This led us to the present study of ruthenium oxide RuO2, nitride RuN2, and sulfide RuS2, wherein we measure the pressure response of physical properties and characterize corresponding crystal structures. We report the discovery of multiple new high pressure phases of RuO2, the first high pressure experiments on RuS2, and the formation of RuN2 while seeking to explore new materials through high-pressure, high-temperature synthesis. These works utilized a combination of high pressure synchrotron x-ray diffraction, in-house Raman spectroscopy, diamond anvil cell electrical transport, laser heating, and cryostat techniques, with additional support and insight from DFT simulations
The Effects of Non-Invasive Brain Stimulation on Excitability of the Primary Motor Cortices and Complex Motor Task Learning
No full textTranscranial direct current stimulation (tDCS) and transcranial alternating current stimulation (tACS) are promising non-invasive brain stimulation techniques, particularly for clinical applications involving altered or impaired motor function, such as in stroke and Parkinson’s disease. Although tDCS and tACS are different modalities, both forms of stimulation operate on the same principle - weak electrical currents are delivered through electrodes placed on the scalp in specific configurations known as “montages”. The most commonly used montage for targeting the primary motor cortex (M1) is the M1-SO configuration. This montage leverages the established observation that cortical regions directly beneath the anode generally increase in excitability, while those beneath the cathode generally decrease in excitability. Consequently, the M1-SO montage places the dominant M1 under anodal stimulation, with the cathode positioned on the contralateral supraorbital area. Many publications using the M1-SO montage report enhancements in motor performance, motor learning, skill retention, fatigue resistance, and increases in M1 excitability. However, despite the abundance of data collected using the M1-SO montage over the last 20 years, several important gaps in knowledge have recently emerged. 1) While many studies claim that twenty minutes of anodal stimulation to the dominant M1 produces an increase in cortical excitability, as quantified by MEPs, the changes that occur in the contralateral, non-stimulated M1 during this concurrent tDCS remain unclear. 2) It has been suggested that tACS does not increase cortical excitability as effectively as tDCS. However, due to its unique ability to induce neuronal entrainment, tACS may be more effective at modulating indirectly targeted brain regions, potentially enhancing clinical outcomes. This raises the question of what changes in cortical excitability, as quantified via MEPs, are observed in the contralateral, non-stimulated M1 when tACS is applied to the dominant M1 concurrently for twenty minutes. 3) While literature suggests that both tDCS and tACS can accelerate motor learning in both healthy and clinical populations, most studies erroneously infer these assumptions based on single-day stimulation protocols and often measure simple, single-joint motor skills as the basis of motor learning. Few publications explore the effects of brain stimulation, especially tACS, over multiple days of stimulation using a complex multi-joint motor skill. Therefore, it is critical to investigate whether multiple days of M1 anodal tACS can enhance motor learning of a complex multi-joint task, such as an overhand throw. In order to address the aforementioned gaps in current literature, the subsequent paragraphs will briefly summarize each chapter of this dissertation.Chapter 1 provides a comprehensive overview of the history, evolution, mechanisms, theories, and specific applications of non-invasive brain stimulation, and introduces relevant motor learning principles to establish a foundation of essential knowledge. The chapter is intentionally written in a clear, non-technical style to ensure that readers, regardless of their initial understanding of brain stimulation and motor learning, can grasp the technical content presented in chapters two through four. The study found in chapter 2 aimed to investigate the effect of tDCS applied to the dominant M1 on the excitability of the contralateral non-dominant M1. Utilizing a double-blind, randomized, SHAM-controlled, within-subjects, crossover design, eighteen young adults participated in two experimental sessions (tDCS and SHAM) in a counterbalanced order with a one-week washout period between sessions. Transcranial magnetic stimulation (TMS) was employed to measure the excitability of the contralateral M1 during 20 minutes of anodal tDCS at a current intensity of 1 mA. TMS assessments were conducted in five test blocks (Pre, D5, D10, D15, and Post). The Pre and Post test blocks were administered immediately before and after tDCS application, while the D5, D10, and D15 blocks were performed at 5, 10, and 15 minutes into the stimulation, respectively. The primary outcome was the 1 mV motor evoked potential (MEP) amplitude. Data were analyzed using a 2 condition (tDCS, SHAM) x 5 test (Pre, D5, D10, D15, Post) within-subjects ANOVA. Results showed no statistically significant main effects for condition (P = 0.213) or test (P = 0.502), nor was there a significant condition x test interaction (P = 0.860). These findings suggest that tDCS does not alter contralateral M1 excitability during or immediately following the stimulation under the tested parameters. Chapter 3 investigates the impact of tACS on the excitability of the non-dominant right M1 when tACS is applied to the dominant left M1. A double-blind, randomized, SHAM-controlled, within-subjects, crossover design was used. Eighteen young adults participated in both tACS and SHAM conditions on separate days in a counterbalanced order with a one-week washout period between sessions. Transcranial magnetic stimulation (TMS) was employed to measure the excitability of the contralateral right M1 while tACS was administered to the left M1. TMS measurements were taken in five blocks (Pre, D5, D10, D15, and Post) relative to a 20-minute session of tACS (70 Hz, 1 mA). The Pre and Post TMS blocks were conducted immediately before and after tACS, respectively, while the D5, D10, and D15 blocks occurred at 5, 10, and 15 minutes during the stimulation. The primary outcome was the 1 mV motor evoked potential (MEP) amplitude. A 2 condition (tACS, SHAM) x 5 test (Pre, D5, D10, D15, Post) within-subjects ANOVA was performed on the MEP data. Results showed no significant main effect for condition (P = 0.704) or for the condition x test interaction (P = 0.349). Although there was a significant main effect for test (P = 0.003), post hoc analysis revealed that none of the pairwise comparisons were statistically significant. These findings suggest that tACS applied to the left M1 does not significantly alter the excitability of the contralateral right M1 during or immediately following the stimulation, at least under the parameters used in this study. Finally, in chapter 4 the primary objective of this study was to evaluate the effect of M1-tACS applied over three consecutive days on the motor learning of a complex overhand throwing task in young adults. Additionally, the study aimed to investigate the impact of M1-tACS on M1 excitability. A double-blind, randomized, SHAM-controlled, between-subjects experimental design was employed. Twenty-four healthy young adults were assigned to either tACS or SHAM groups and participated in three identical experimental sessions. Each session involved blocks of overhand throwing trials with the right dominant arm while tACS was applied to the left M1. Performance was measured by endpoint error. To assess changes in M1 excitability, motor evoked potentials (MEPs) were recorded from the right first dorsal interosseous (FDI) muscle using transcranial magnetic stimulation (TMS). Results showed a significant reduction in endpoint error from pre-test to post-test across the three days of practice (P = 0.046), but no significant difference between the tACS and SHAM groups (P = 0.474). MEP amplitudes increased from pre-test to post-test (P = 0.003), yet these increases did not significantly differ between the groups (P = 0.409). Overall, the findings suggest that M1-tACS over multiple days does not enhance motor learning of a complex task more than practice alone (SHAM)
How Couples Navigate Interethnic Differences in Asian American Population: A Grounded Theory Approach
No full textSeveral studies have discussed the impact of cultural factors in Asian American families. Previous research has demonstrated useful strategies used in dealing with distress and relationship dissatisfaction regarding cultural differences. There is limited data or studies that explore additional challenges faced by interethnic couples, rather than interracial couples and the impact of family dynamics on these relationships. Each partner’s identity development process was influenced by their understanding of different cultural traditions and customs. These unique experiences shaped their understanding of roles and expectations within their relationship and parenting styles. Additionally, these family relationships and cultural backgrounds play a role in the assimilation and acculturation process impacting how these couples navigate these dynamics. There are many misconceptions and stereotypes regarding Asian populations, and it would be important to address these aspects to gain a better understanding of potential issues they may face. It is significant to understand the process in how Asian American couples navigate their interethnic differences regarding cultural expectations and child-rearing practices. Grounded Theory is a qualitative method that was implemented in the study to analyze the data from a semi-structured interview with heterosexual Asian American couples who are from different ethnic background in the United States. This approach provided the appropriate framework to construct a theory and exploring the process of how Asian American couples navigate the cultural factors within their relationship. The themes that emerged from the data show six themes that demonstrate the process of how Asian American couples navigate the unique cultural experiences coming from very distinct ethnic backgrounds. The themes are family dynamics, identity development, culture and community, communication, expectations, and strategies to manage some challenges. Some of the strategies that were applied to manage the challenges around cultural differences include cultural adaptability and sensitivity
Carbon Dioxide Adsorption Capacities of Unmodified Biochar Derived From the Great Basin Desert Ecosystem
No full textClimate change and wildfires are two interconnected crises that present a great danger to the American southwest. Anthropogenic greenhouse gases including carbon dioxide have warmed the earth, creating droughts and altering weather patterns so that wildfires have increased in severity and intensity within the region. Wildfires in turn release stored carbon from biomass into the atmosphere, creating a dangerous feedback loop that destroys vast swaths of land in areas including the Great Basin Desert of northern Nevada and surrounding states. Fuel breaks offer a method to slow the spread of wildfires but are costly and generate large amounts of waste biomass material. This material can be transformed into biochar (BC), a porous carbonaceous material that sequesters carbon and can adsorb CO2 to assist in stopping climate change. In this thesis, four materials found in the Great Basin Desert (pinyon pine wood and needles, big sagebrush, and cheatgrass) were transformed into biochar at pyrolysis temperatures of 500 C, 600 C, and 700 C and studied for their materials characteristics. These biochars were then tested for their CO2 adsorption abilities via thermogravimetric analysis (TGA) and a column study. Materials characterizations found that cheatgrass biochar had an especially high BET surface area (428.73 m2/g at 700 C), while pinyon pine needle biochar had a high nitrogen content, which is linked to increased material basicity. Additionally, Fourier transform infrared spectroscopy analysis indicated a decrease in the acidic oxygen functional group O-H bend (carboxylic acid) for all materials as pyrolysis temperature increased. TGA testing showed that all materials had similar adsorption properties at the same pyrolysis temperatures with adsorption increasing as temperature increased, while column studies measured lower adsorption values but suggested that cheatgrass BC had a significantly higher adsorption than the other tested materials. These results indicate that physisorption through high surface area and chemisorption through high basicity are both strong influencing factors to CO2 adsorption. Additionally, this study shows that higher pyrolysis temperatures are beneficial to adsorption for these four materials, with cheatgrass pyrolyzed at 700 C having the highest adsorption value of 73.3 mg CO2/g BC via TGA testing. This study can be expanded in the future to include a greater range of pyrolysis temperatures and times, an expanded column study, and adsorption testing under different gas conditions
The Assignment Despite Objection Construct: Its Efficacy and Utility in Measuring Nurse-Perceived Unsafe Staffing Events and Associated Outcomes
No full textPurpose: This three-manuscript approach provided a progressively built overview of Assignment Despite Objection as a construct used by nurses to document their perceptions of unsafe staffing events and as an unstudied concept in the staffing outcomes literature.
Background: All nurses have an ethical, legal, and professional responsibility to refuse or object to assignments they believe are unsafe for their well-being or their patient’s safety. Assignment Despite Objection being the only widely used construct nurses use to document these perceptual details. No studies have focused on Assignment Despite Objection as a construct or concept, leaving a complete gap in understanding its efficacy, practical utility, and accuracy as a measure of unsafe staffing events.
Methods: Each study’s results helped to elucidate a foundational view of Assignment Despite Objection. Study one, a qualitative descriptive study, identified content patterns associated with various nurse, patient, and work environment characteristics found on Assignment Despite Objection forms. Studies two and three used a quantitative descriptive design and secondary data. The unit of observation and analysis was the unit level. Statistical analyses included repeat linear regression, Poisson regression, and descriptive tests.
The study setting was the University Medical Center of Southern Nevada, a 541-bed integrated academic health system in Las Vegas, Nevada. The sample comprised 864 patient encounters over 17 medical-surgical and critical care nursing units and 511 Assignment Despite Objection submissions that met inclusion criteria between the second quarter of the calendar year 2017 and the third quarter of 2023.
Results: Content patterns involving nurse, patient, and work environment characteristics were identified, including narrative information, resourcing, and workload details. There is a positive association between Assignment Despite Objection and adverse patient safety events. The severity and reasons for Assignment Despite Objection, strongly predicted the overall incidence of medical emergency response team requests, patient transfer needs, and patient mortality.
Implications: Assignment Despite Objection offers a reasonable and accurate mechanism for nurses to identify and document unsafe staffing events. These findings guide pragmatic interventions and reinforce the need for granular research at the unit and shift levels using the voice of clinical nurses as expert stakeholders