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Measuring electrical properties of batteries at ultra-long timescales
No full textQuantifying battery behavior is critical to development of new battery technologies and energy storage systems. While it is straightforward to measure properties such as impedance at short timescales (i.e. frequencies larger than ~1 Hz) the relevance of this is questionable since rechargeable batteries in normal usage are often cycled on timescales of hours or days. Making measurements at these timescales, for example impedance measurements below ~1 mHz, is more challenging. In this paper we discuss approaches to quantifying battery behavior at timescales from hours to weeks (frequency scales of ~0.1 mHz down to ~1 μHz). We present frequency domain measurements and time domain measurements, achieved through four-point measurements with a Keysight 66332A at around 100 mA RMS. At low frequencies significant charge is shifted in a measurement cycle, complicating interpretation. The digitization of a sine-wave may introduce errors such as constant current offsets that build in significance with time. The operating point (DC voltage level) of the battery should be controlled since it influences impedance at the lowest frequencies as a result of the voltage-dependent nature of different electrochemical processes. We relate the voltage-dependent effects to time-domain measurements such as cyclic voltammetry and incremental capacity analysis
Risk assessment for family violence aggressors in Aotearoa New Zealand
Get PDFIn recent decades Family Violence (FV) researchers have developed risk assessment instruments to enable practitioners to identify the people who are most likely to commit FV in the future, and the families who are most likely to experience ongoing harm. Indeed, risk assessments have become a standard procedure for FV practitioners who are frequently required to make decisions with potential ramifications for families’ safety and wellbeing. Yet, despite considerable developments in risk assessment research and practice, risk assessment instruments have limitations that curb their value to FV practice. In addition, such instruments should be empirically validated, but there is limited evidence for the validity of risk assessment instruments used by agencies that respond to FV in Aotearoa New Zealand. Therefore, in this thesis, we examined the risk assessment procedures that New Zealand Police and the Integrated Safety Response (ISR) used for FV, with the purpose of contributing to the evidence base about risk assessment for FV in New Zealand and identifying strengths, weaknesses, and opportunities for improvement.
This thesis contains three manuscripts either published in or submitted to peer-reviewed academic journals; as well as supplementary chapters that support, extend, and integrate the research findings. In the first manuscript, we examined the predictive validity of risk categories from the Dynamic Risk Assessment for family violence (DYRA) and Static Assessment of Family Violence Recidivism (SAFVR)—the two risk assessment instruments that New Zealand Police use when responding to FV cases—for a sample of 2,115 cases with FV episodes reported to police in Waikato and parts of Canterbury between 1 November – 9 December 2018 (1,817 of which had complete risk categories). We examined the instruments’ ability to predict recurrence (i.e., a further FV-related call for police service) at three intervals (3 days, 12 weeks, and 24 weeks), and found both instruments had a poor ability to discriminate between aggressors who had a recurrence and those who did not, with the SAFVR outperforming the DYRA, and the DYRA performing especially poorly for non-intimate partner cases, and aggressors who were Māori or women.
In the second manuscript, we explored the risk assessments that Integrated Safety Response (ISR) triage team members conducted for a sub-sample of 842 cases with FV episodes reported to police between 1 – 14 November 2018. We examined the relationship between the factors triage teams recorded during their risk assessments and the risk categories the teams assigned, then tested the association of both the factors and categories with recurrence and physical recurrence within 24 weeks. The predictive validity of ISR triage teams’ risk categories was comparable to the results produced for the DYRA and SAFVR in manuscript one. The ISR risk categories again performed poorly for aggressors who were women, Māori, and for non-intimate partner cases; and overall, fewer than half of the factors triage teams recorded were associated with recurrence or physical recurrence. Then, in an additional chapter, we explored the triage teams’ factors’ utility for case management and found the factors could be used to create three sub-groups of cases with potential implications for their treatment and management.
Finally, in the third manuscript, we modeled the behavioral patterns of 2,115 aggressors with a FV episode reported to police in Waikato and parts of Canterbury between 1 November – 9 December 2018, by collecting reports for further FV episodes involving those aggressors during the two years after the index episode. We used this information to describe three latent states behind the information reported to police and identified four common pathways through the latent states over time. We concluded this manuscript by discussing changes that could contribute to improvements in how risk for FV aggressors is conceptualized, assessed, and communicated in practice.
In each chapter, we discussed the theoretical and practical implications of the findings, before integrating those findings and implications in a general discussion chapter. Taken together, the results presented herein indicate that the risk assessment instruments used in New Zealand can predict risk for FV recurrence better than chance, but that those assessments should be further developed to improve their value to FV practice and ensure they adequately capture risk for different types of FV cases and groups of people. This thesis advanced our understanding of the limitations of—and opportunities in—risk assessment research and contributed to the evidence base for risk assessment for FV in New Zealand
Establishing conversion of the 16-item Informant Questionnaire on Cognitive Decline in the Elderly scores into interval-level data across multiple samples using Rasch methodology
Get PDFBACKGROUND: The 16-item Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE-16) is a well-validated and widely-used measure of cognitive changes (CCs) among older adults. This study aimed to use Rasch methodology to establish psychometric properties of the IQCODE-16 and validate the existing ordinal-to-interval transformation algorithms across multiple large samples.
METHODS: A Partial Credit Rasch model was employed to examine psychometric properties of the IQCODE-16 using data (n = 918) from two longitudinal studies of participants aged 57-99 years: the Older Australian Twins Study (n = 450) and the Canberra Longitudinal Study (n = 468), and reusing the Sydney Memory and Ageing Study (MAS) sample (n = 400).
RESULTS: Initial analyses indicated good reliability for the IQCODE-16 (Person Separation Index range: 0.82-0.90). However, local dependency was identified between items, with several items showing misfit to the model. Replicating the existing Rasch solution could not reproduce the best Rasch model fit for all samples. Combining locally dependent items into three testlets resolved all misfit and local dependency issues and resulted in the best Rasch model fit for all samples with evidence of unidimensionality, strong reliability, and invariance across person factors. Accordingly, new ordinal-to-interval transformation algorithms were produced to convert the IQCODE-16 ordinal scores into interval data to improve the accuracy of its scores.
CONCLUSIONS: The findings of this study support the reliability and validity of the IQCODE-16 in measuring CCs among older adults. New ordinal-to-interval conversion tables generated using samples from multiple independent datasets are more generalizable and can be used to enhance the precision of the IQCODE-16 without changing its original format. An easy-to-use converter has been made available for clinical and research use
Green space justice amid COVID-19: Unequal access to public green space across American neighborhoods
Get PDFCountries around the world have resorted to issuing stay-at-home orders to slow viral transmission since the COVID-19 pandemic. During the lockdown, access to public park plays a central role in the public health of surrounding communities. However, we know little about how such an unprecedented policy may exacerbate the preexisting unequal access to green space (i.e., green space justice). To address this research void, we used difference-in-difference models to examine socioeconomic disparities, urban-rural disparities, and mobility disparities in terms of public park access in the United States. Our national analysis using the weekly mobile phone movement data robustly suggests the following three key findings during COVID-19: (1) The elderly, non-college-educated people, poor people, and blacks are less likely to visit public parks frequently, while unemployed people appear to be the opposite. (2) Compared to rural areas, populations in urban neighborhoods appear to visit public parks more frequently and they generally go to larger parks to minimize the risk of infection. (3) Populations in neighborhoods with higher private vehicle ownership or those with a higher density of transit stops would more frequently visit and travel a longer distance to public parks during the stay-at-home order. Our results imply that conventional inequality in green space access may still exist and even become worse during COVID-19, which could negatively impact people's health during isolation. We suggest that special attention should be paid to park-poor neighborhoods during the pandemic and in the post-pandemic recovery phase
Differentiating the temperature response of soil fungi and bacteria
Get PDFThe decomposition of soil organic matter (SOM) may be accelerated under increasing temperatures from climate change, which could create feedback loops that result in the loss of soil carbon (C) stocks. Fungi and bacteria regulate the decomposition of SOM, each having their own unique adaptations that allow them to fulfill different roles in the decomposition process. However, fungi and bacteria may respond to temperature differently which could complicate soil C cycling dynamics. To date, few studies have attempted to differentiate the temperature response of fungal and bacterial respiration.
The aim of this research was to differentiate the temperature optima (Tₒₚₜ) and inflection point temperatures (Tᵢₙբ) of fungal and bacterial respiration. The Tₒₚₜ is the temperature at which respiration is maximal whereas the Tinf is the point at which respiration is most sensitive to temperature.
Soils were collected from different locations along a geothermal temperature gradient (that had average temperatures between ~13-39 °C). The selective inhibition method was used to differentiate the temperature response of fungal and bacterial respiration by treating soils with streptomycin and cycloheximide, respectively. Soils were also treated with and without glucose to determine the non-substrate limited respiration response of fungal and bacterial respiration. Treated soils were incubated in a temperature block that allowed the incubation of soils at temperatures ranging between ~5-52 °C for five hours. Headspace samples were taken from each treatment tube and injected into an infrared gas analyser (IRGA) to measure carbon dioxide (CO₂) concentrations and respiration rates. Macromolecular rate theory (MMRT) was used to model the temperature response of the respiration curves to derive the Tₒₚₜ and Tᵢₙբ of fungal and bacterial respiration, allowing the comparison of the temperature responses of fungal and bacterial respiration.
An additional aim of this research was to measure changes in fungal and bacterial biomass along the geothermal temperature gradient using phospholipid fatty acid (PLFA) analysis. Soil samples were collected from the same sampling locations along the geothermal temperature gradient as those used in the selective inhibition experiments. A modified Bligh and Dyer method was used to extract phospholipids from soil samples, which were used as biomarkers to differentiate the biomass of different fungal and bacterial groups.
Results from selective inhibition experiments showed that respiration rates decreased from streptomycin and cycloheximide treatment, allowing an estimation of fungal and bacterial contributions to total soil respiration, respectively. Fungal contributions to soil respiration (~55%) were greater than bacterial contributions (~21%), suggesting that fungi contribute more to soil C decomposition than bacteria. Furthermore, the Tₒₚₜ of fungal respiration was found to decrease with environmental temperature at a rate of -0.396 °C °C-1 whereas the Tₒₚₜ of bacteria and the microbial community was not correlated with environmental temperature. Additionally, the Tₒₚₜ and Tᵢₙբ of fungal respiration (38.6 °C and 22.1 °C, respectively) was not significantly different from the Tₒₚₜ and Tᵢₙբ of microbial respiration (37.0 °C and 21.7 °C, respectively) but was significantly greater than the Tₒₚₜ and Tᵢₙբ of bacterial respiration (30.4 °C and 19.0 °C, respectively). Results from PLFA analysis showed that gram-positive bacteria and general bacteria dominated total microbial biomass and biomass from identified fungal and bacterial groups peaked at ~19-21 °C. Fungal-to-bacterial (F:B) ratios decreased with increasing environmental temperature, indicating a proportional decrease in fungal biomass relative to bacteria at higher temperatures. These results suggest that fungi were excluded with increasing environmental temperature as they were unable to adapt their metabolism and growth as environmental temperatures increased.
The selective inhibition method presented a range of limitations that may have constrained interpretation of the results. First, inhibitors were not equally effective across the range of incubation temperatures. Inhibition from cycloheximide showed a clear temperature optimum where inhibition was greatest within ~45-50 °C. In contrast, inhibition from streptomycin declined at temperatures above ~30 °C. Secondly, percent inhibition of microbial respiration from streptomycin increased as total bacterial biomass increased, providing evidence that streptomycin was effective in targeting bacteria. In contrast, percent inhibition of microbial respiration from cycloheximide was not correlated with fungal biomass, indicating that cycloheximide may not have been effective in selectively targeting fungi.
Overall, these results indicate that fungi may be more at risk from increasing temperatures under climate change, though it is unknown as to how this could translate to soil C stocks. This was likely the first study that attempted to differentiate the temperature response of fungi and bacteria by selectively inhibiting fungi and bacteria and incubating them across a range of temperatures. However, caution should be taken when interpreting results as a range of methodological constraints were uncovered regarding the veracity of the selective inhibition method. While previous studies have reported some limitations of the selective inhibition method, these issues have likely been under-reported as researchers may not publish inconclusive or negative results. Therefore, this study also highlights the importance of critically assessing methods that may be ineffectual
Video quality assessment considering the features of the Human Visual System
Get PDFNowadays, numerous video compression quality assessment metrics are available. Some of these metrics are “objective” and only tangentially represent how a human observer rates video quality. On the other hand, models of the human visual system have been shown to be effective at describing spatial coding. In this work we propose a new quality metric which extends the peak signal to noise ratio metric with features of the human visual system measured using modern LCD screens. We also analyse the current visibility models of the early visual system and compare the commonly used quality metrics with metrics containing data modelling human perception. We examine the Pearson’s linear correlation coefficient of the various video compression quality metrics with human subjective scores on videos from the publicly available Netflix data set. Of the metrics tested, our new proposed metric is found to have the most stable high performance in predicting subjective video compression quality
When the law is unclear: challenges and opportunities for data and information exchange in the Tigris-Euphrates and Indus river basins
Get PDFData and information exchange are vital for long-term transboundary water cooperation. However, many transboundary river basins lack regular data exchange between riparian States. In many cases, this is simply a feature of the generally fragmented nature of transboundary water cooperation; in others, transboundary river basin data sharing may be withheld for geopolitical reasons. The Tigris-Euphrates and Indus river basins are among the most highly politicized river basins globally. Cooperation between riparians is complicated by a lack of certainty regarding data, information exchange and legal obligations, as upper riparians in both basins have persistently objected to the customary law of international watercourses. With reference to international water law, this article ascertains the level of data and information exchange in these two basins, both through formal and informal structures, as well as prevalent obstacles and the institutional and technological responses to them. Despite significant challenges, the authors argue that technological advances can stimulate enhanced riparian cooperation
Mental Rehearsal Improves Passing Skill and Stress Resilience in Rugby Players.
Get PDFPURPOSE: Mental rehearsal is commonly employed, with positive visualization proposed to enhance complex skill performance. Additionally, video stimulus has been associated with enhanced kinesthetic sensations and rapid hormone fluctuations that may contribute to enhancing mental rehearsal and the conscious and unconscious emotional state for skill execution. Here, we assessed the impact of a 15-minute mental rehearsal intervention on rugby-specific tasks and the associated hormone profile. METHODS: Professional rugby players (N = 10) volunteered for a randomized crossover study. They completed three 15-minute preparatory phases (positive or negative video-guided mental rehearsal or self-directed mental rehearsal alone) prior to an exercise stressor and rugby-specific passing task. Salivary testosterone and cortisol were monitored to assess stress responses. RESULTS: Performance during the rugby passing task was improved following the positive video condition (91% [7.4%]) compared to the negative video (79% [6.0%]; ES: 1.22 ± 0.75) and self-visualization (86% [5.8%]; ES: 0.58 ± 0.75), with a significant correlation observed between passing performance and salivary testosterone (r = .47 ± .34, P = .0087). Positive video imagery prior to an exercise stressor also significantly enhanced physiological stress resilience (r = .39 ± .36, P = .0352). CONCLUSIONS: This pilot study demonstrates that mental rehearsal was enhanced by appropriate, context-specific video presentation. We propose that the interaction between sex steroids, the adrenal axis, and subsequent conscious and unconscious behaviors may be relevant to competitive rugby. Specifically, we suggest that relatively elevated free testosterone imparts a degree of stress resilience, which may lead to enhanced expression of competitive behaviors and provide an enhanced state for rugby skill execution
The inherent liminality of lesbian detectives: Shifting spaces and lesbian crime fiction 1984-2022
Get PDFThis thesis studies lesbian detective fiction and specifically considers this genre in its early decades (1980s-1990s) from the United States, United Kingdom, Australia, and New Zealand. This thesis postulates that out of a sample pool of a hundred novels, there are recurring patterns of behaviours and attitudes among the protagonists of this genre within certain physical and metaphorical spaces. These patterns demonstrate a destabilised identity, as the lesbian sleuth never ceases to explore and test the boundaries of her authority as an enforcer of law and order and of her suppressed spatiality as a member of a sexual minority. This causes her to live in a perpetual state of Insider/Outsider liminality and it causes queer trauma to be a fundamental aspect of her character. This thesis considers this concept as the result of long-standing, systemic homophobia and heterosexist normativity, and utilises the notion of queer trauma to interpret the way the lesbian sleuth is inescapably stuck between a sense of duty and justice and a yearning for belonging and self-affirmation. The interpretive process is supported by an extensive and in-depth theoretical research into the fields of history, culture, geography, feminist criticism, gender, and sexuality studies for the selected subject matter. The spaces selected and analysed in this thesis are the queer closet, the medical establishment, domestic settings, and the gay bar. These spaces have been chosen for the significant, emblematic ways in which the lesbian detectives interact with them and have been analysed in order of their importance for the protagonists’ characterisation. The introduction includes introductory statements and the theoretical framework, the first chapter overviews major detectives in the history of crime literature from a spatial perspective; the second chapter discusses the queer closet; the third chapter considers the space of the clinic and the topics of queer trauma and of the pathologisation of homosexuality; the fourth chapter analyses the domestic settings of the protagonists; the fifth chapter examines the context of the gay bar and its history; finally, the conclusion offers closing statements about the focus and originality of this thesis. The originality of this thesis lies in its focus on spaces and on the relationship between the protagonist and society, law and order, and Self and Other. This thesis contributes to the knowledge of queer literature by specifically considering the unescapable liminality of the lesbian/Outsider detective/Insider
A systematic review of volcanology learning and teaching in higher education
Get PDFWe present a systematic map of the volcanology higher education literature (1983–2020) consisting of 47 peer-reviewed full texts. The literature describes curricula in varied formats and settings, namely: simulated, in-person, and field-based learning. The phenomena that students are learning about commonly include volcanic processes and landforms, applicable to learning within various geoscience subdisciplines. Frequently published research includes volcano misconceptions and simulated eruptions. However, most texts focus on practitioner wisdom and lack research information, empirical evidence, and/or a research-oriented methodology. A lack of research orientation is a documented phenomenon within the broader field of geoscience education, which is young compared to other discipline-based education research fields. Based on our findings, we recommend future research in conceptual learning of volcanology, instructional strategies, volcanology and society interactions, volcanology education equity and inclusion, volcanology cognition, quantitative learning, affective learning, and institutional change in volcanology