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Molecular dynamics simulations and experimental measurements of density and viscosity of phase change material based on stearic acid with graphene nanoplatelets
Get PDFUnderstanding the thermophysical properties of nano-enhanced phase change materials (NEPCMs) is crucial for developing thermal energy storage technologies. Thermal conductivity of NEPCMs is the most studied property, but investigations on density and viscosity are scarce. In this paper, the viscosity and density of pure stearic acid (SA) and stearic acid with 2 wt.%, 4 wt.%, and 6 wt.% graphene nanoplatelets (GNPs) of 6–8 nm thickness have been investigated from 343 K to 373 K at atmospheric pressure. The SA with GNP concentrations of 4 and 6 wt.% exhibits non-Newtonian behaviour, meaning that viscosity depends on shear rate. The viscosity and density for SA with 2 wt.% GNPs were measured, and the uncertainties for each property were calculated. Two empirical equations were used to correlate the viscosity and density data along the isotherms. Molecular dynamics simulations were performed to compute the density and viscosity and understand the molecular interaction of the GNP +SA system. A GNP nanoparticle (18-layer graphene nanoplate) embedded in 2123 SA molecules was simulated in a temperature range from 353 K to 378 K at a pressure of 0.1 MPa. The viscosity and density properties of a pure SA liquid and the GNP + SA system are compared with the experimental data. The orientation of the SA molecules for the pure SA and in the presence of GNP is investigated using the radial distribution function. The simulated density and viscosity exhibit the same trend as the experimental data. The simulations demonstrated that the GNP reorganises SA molecules on its surface, indicating a higher linear alignment of aliphatic chains of SA and, as a result, a greater local density of SA around the nanoplatelet
Creating a Cross-Race Effect Inventory to Postdict Eyewitness Accuracy
Get PDFObjective: The Cross-Race Effect (CRE) is a reliable and robust phenomenon, whereby individuals better recognize faces that belong to their race compared to another race. Our goal was to produce items for a self-report Inventory (i.e., CRE-I) that brings together known predictors of the CRE to improve the postdiction of cross-race eyewitness accuracy.Hypotheses: We expected a CRE for White and Asian participants. We anticipated that developed CRE-I subscales would correlate positively with extant (some modified) scales and predict accuracy. Method: Participants completed four trials (two White targets and two Asian targets). For each trial, they watched a mock crime video, performed a distractor task, made a sequential lineup decision (target-present or target-absent), and indicated confidence in their lineup decision. After all trials, participants completed the potential items for the CRE-I.Results: We replicated prior findings of a CRE for White participants but did not find a CRE for Asian participants. Exploratory factor analysis produced internally reliable scales for the CRE-I to be used with White eyewitnesses: general face recognition ability, race-specific face recognition ability, racial attitudes, quantity of contact, quality of contact, motivated individuation, and cognitive disregard. Responses to several scales predicted identification accuracy. In particular, three CRE-I scales predicted identification accuracy beyond the predictiveness of confidence: race-specific face recognition ability, racial attitudes towards White people, and motivated individuation of White people. Conclusions: Variables suggested separately by the perceptual expertise hypothesis and the social cognitive hypothesis predicted identification accuracy, providing support for integrative models of the CRE. The CRE-I contributes to the CRE literature both in terms of theory—by showing which factors among many may best relate to recognition—and practice—by improving evaluations of eyewitness reliability
Exploring Adolescent Contraceptive Use: The Voices of Parents/Guardians from a Selected Hospital in Lesotho
Get PDFSexual and reproductive health (SRH) services have drawn much attention in most African countries. Special focus had been directed toward the utilization of sexual and reproductive health services by adolescents aged 15 to 19 years old. However, little is known about parental and guardians' roles in optimizing the utilization of sexual and reproductive health services by adolescents 15 – 19 years in Leribe district, Lesotho. The study aimed to explore the perceptions and experiences of parents and guardians regarding contraceptive use by adolescents to prevent teenage pregnancy in the Leribe district. A qualitative exploratory study design was done using one-on-one semi-structured interviews with parents and guardians raising adolescents aged 15-19 years in their homes. Twelve parents and guardians attending healthcare services at the selected hospital were purposively selected to participate in the study. Data was analyzed using six steps of Thematic data analysis by Braun and Clarke. Six themes were identified from the study, parents and guardians knew about contraceptives and their use, contraceptive use was understood to prevent problems to the family, contraceptives were viewed as resulting in unfavorable behaviour to adolescents, experiences on sexual health communication were considered as significant and non-significant, outreach services were needed to reach vulnerable adolescents, and awareness about contraceptive use by adolescents. Participants were aware of the prevailing situation of teenage pregnancy and its consequences. That is why they advocated for contraceptive use by adolescents and engage in sexual health communication for their adolescents to make the right decisions concerning SRH issues
How do firms respond to climate change? Evidence based on ESG performance
Get PDFClimate change has become an unavoidable external force influencing firms’ operations by reshaping policy environments and raising societal expectations. As a result, firms are compelled to adopt measures to address these challenges. This study examines the causal relationship between climate change and firms’ ESG (Environmental, Social, and Governance) performance using data from Chinese manufacturing firms listed between 2009 and 2021, while controlling for firm-specific and climate-related factors. The findings reveal that temperature deviation (TD) significantly improves firms’ ESG performance, a result that remains robust across various tests. Moreover, TD enhances ESG performance primarily through reputation and costs channels, with stronger effects observed in firms with low reputations compared to high-reputation firms, and in high energy-consuming firms compared to those with low energy consumption. This study offers a novel perspective on how climate change impacts firms at the operational level and provides actionable recommendations for governments to support and promote improved ESG performance
The relationship between frailty syndrome and quality of life in patients with hypertension: a multidimensional analysis
Get PDFBackground: Hypertension is a common condition among the elderly and is frequently accompanied by frailty syndrome (FS). The coexistence of hypertension and FS poses significant challenges in patient management and negatively impacts the quality of life (QoL). This study aimed to analyze the relationship between FS and QoL in elderly patients with suspected hypertension. Methods: A cross-sectional study was conducted involving 201 patients aged 65 years or older, referred to a Hypertension Clinic for diagnostic evaluation. Frailty was assessed using the Tilburg Frailty Indicator (TFI), and QoL was evaluated with the World Health Organization Quality of Life Instrument (WHOQOL-BREF). Sociodemographic and clinical data were collected, and statistical analyses were performed to identify correlations between FS and QoL. Results: The study found that 79.60% of the patients were identified as frail (TFI ≥ 5). FS was significantly negatively correlated with all domains of QoL, including physical health (r = -0.634, p < 0.001), psychological health (r = -0.675, p < 0.001), social relationships (r = -0.528, p < 0.001), and environmental factors (r = -0.626, p < 0.001). Multivariate analysis revealed that physical (β = -0.091, p < 0.001) and psychological components of FS (β = -0.128, p = 0.016), as well as age (β = -0.022, p = 0.004), were significant predictors of lower QoL scores. Loneliness (β = -0.235, p = 0.049) was also a significant predictor of lower QoL. Conclusions: The study demonstrated a strong association between FS and reduced QoL in elderly hypertensive patients, emphasizing the need for comprehensive assessments and personalized management strategies. Routine evaluation of frailty and the implementation of targeted interventions aimed at improving physical, psychological, and social well-being could substantially enhance QoL in this vulnerable population. Clinical trial number: Not applicable
Neurosymbolic learning and domain knowledge-driven explainable AI for enhanced IoT network attack detection and response
Get PDFIn the dynamic landscape of network security, where cyberattacks continuously evolve, robust and adaptive detection mechanisms are essential, particularly for safeguarding Internet of Things (IoT) networks. This paper introduces an advanced anomaly detection model that utilizes Artificial Intelligence (AI) to identify network anomalies based on traffic features, explaining the most influential factors behind each detected anomaly. The model integrates domain knowledge stored in a knowledge graph to verify whether the detected anomaly constitutes a legitimate attack. Upon validation, the model identifies which core cybersecurity principles—Confidentiality, Integrity, or Availability (CIA)—are violated by mapping influential feature values. This is followed by an alignment with the MITRE ATT&CK framework to provide insights into potential attack tactics, techniques, and intelligence-driven countermeasures.By leveraging explainable AI (XAI) and incorporating expert domain knowledge, our approach bridges the gap between complex AI predictions and human-understandable decision-making, thereby enhancing both detection accuracy and result interpretability. This transparency facilitates faster responses and real-time decision-making while improving adaptability to new, unseen cyber threats. Our evaluation on network traffic datasets demonstrates that the model not only excels in detecting and explaining anomalies but also achieves an overall detection accuracy of 0.97 with the integration of domain knowledge for attack legitimacy. Furthermore, it provides 100% accuracy for threat intelligence based on the MITRE ATT&CK framework, ensuring that security measures are verifiable, actionable, and ultimately strengthen IoT environment defenses by delivering real-time threat intelligence and responses, thus minimizing human response time
A logic model and multinational consensus definition of primary palliative care in sub-Saharan Africa
Get PDFBackgroundThe number of people needing palliative care is rapidly increasing in sub-Saharan Africa (SSA) . Healthcare systems in SSA are heterogenous, so broadly defining and operationalizing primary palliative care is a major obstacle to achieving Universal Health Coverage. We aimed to conceptualize and operationalize primary palliative care in SSA by developing an evidence-based logic model and consensus definition.MethodsWe purposively sampled expert participants in a workshop in Harare, Zimbabwe. They collaboratively developed a logic model using the Centers for Disease Control and Prevention's guide for developing and using logic models and a consensus definition using modified nominal group technique.ResultsTwenty-four primary palliative care experts comprised of researchers (70.1%), physicians (37.5%) and nurses (29.2%) from 8 countries (7 in SSA) participated. Twenty (83.3%) participants fell into multiple role categories. Primary palliative care essential resources (i.e., medications, funding, health workers), activities (i.e., clinical guidelines and referral pathway development, education), outputs (i.e., care pathways, cost-benefit ratios), and outcomes (i.e., improved quality of life, skilled primary palliative care workforce, reduced health-related suffering) relevant for countries in SSA were identified. To define primary palliative care in SSA, participants identified and ranked crucial components, including holistic care (provided by health workers with role-appropriate training), culturally congruent delivery of care, and accessibility at the entry point of healthcare systems. The definition highlights that "primary" pertains to how people access care, rather than who or where it is provided.ConclusionThe identified essential components of primary palliative care address the region's specific context, challenges and strengths. Training the existing primary healthcare workforce in palliative care and providing necessary support and resources must be prioritized in order to improve outcomes in SSA
The Scottish Safe Staffing Act at Baseline: Quantitative Findings
Get PDFIntroduction: Amid a global nurse staffing crisis, in 2019 Scotland legislated the Health and Care (Staffing) (Scotland) Act to address health care workforce challenges. Instead of requiring patient-to-nurse ratios as legislated elsewhere, this Act requires staffing decisions according to guiding principles, duties, and a common staffing method. Measuring variation in hospitals’ adherence to the Act’s provisions at baseline is important for policymakers to evaluate fulfillment of the act’s requirements and goals. Results will inform policymakers about which provisions are achieved at baseline and which require support for employers to achieve. The purpose of the study was to establish the baseline of nurse staffing standards in Scotland at April 2024 implementation of the Act. Nurse reports of quality, safety, and their intent to leave were measured to complement assessment of the implementation status.Design/Methods: A cross-sectional study design was used. A convenience sample of registered nurses and nursing support workers was recruited through professional organizations and trade unions. Nurses were invited to complete an online survey between May 1 and July 31, 2024. The survey content included demographic and professional characteristics, international nursing metrics, the Act’s provisions, and job intentions. Descriptive statistics were calculated to describe the sample, Act’s provisions, and nurses’ job intentions.Results: The sample comprised 1,870 nurses, of whom 93% were registered nurses, from all regions with characteristics reflecting the Scottish nursing workforce. Regarding the Act’s provisions, 9% reported that nursing staffing is appropriate to provide safe, high-quality care every shift. Similarly, few nurses reported that quality of care was excellent (17%) or graded safety an A (10%). Most nurses disagreed that current staffing levels met the eight guiding principles. Most nurses reported that the common staffing method and duties regarding real-time staffing decisions were followed at best occasionally. Nearly half of nurses (45%) intend to stay in their current job over the next year. Among those intending to leave their current job, about half plan to leave the profession through retirement or another unspecified job change. The other half plan to seek another similar nursing job or promotion.Conclusion: Few nurses report that the Act’s overarching goal is being met at the point of implementation. Although most nurses see nursing as a long-term career, workforce disruption is anticipated through routine turnover, promotion, or retirement, requiring workforce retention policies. Whether the Act’s complex provisions can be achieved, and its goals fulfilled, may not reverse the trend of exiting nurses. The complexity of the approach will be a challenge to achieving the objective of safe staffing. Therefore, this approach to achieving safe staffing may be too complex to be recommended widely. These remain urgent questions for Scottish policymakers, nurse leaders, and researchers
Passivity theorems for input-to-state stability of forced Lur’e inclusions and equations, and consequent entrainment-type properties
Get PDFA suite of input-to-state stability results are presented for a class of forced differential inclusions, so-called Lur’e inclusions. As a consequence, semi-global incremental input-to-state stability results for systems of forced Lur’e differential equations are derived. The results are in the spirit of the passivity theorem from control theory as both the linear and nonlinear components of the Lur’e inclusion (or equation) are assumed to satisfy passivity-type conditions. These results provide a basis for the analysis of forced Lur’e differential equations subject to (almost) periodic forcing terms and, roughly speaking, ensure the existence and attractivity of (almost) periodic state- and output-responses, comprising another focus of the present work. One ultimate aim of the study is to provide a robust and rigorous theoretical foundation for a well-defined and tractable “frequency response” of forced Lur’e systems
Dynamic properties of a class of forced positive higher-order scalar difference equations: persistency, stability and convergence
Get PDFPersistency, stability and convergence properties are considered for a class of nonlinear, forced, positive, scalar higher-order difference equations. Sufficient conditions for these properties to hold are derived, broadly in terms of the interplay of the linear and nonlinear components of the difference equations. The convergence results presented include asymptotic response properties when the system is subject to (asymptotically) almost periodic forcing. The equations under consideration arise in a number of ecological and biological contexts, with the Allen-Clark population model appearing as a special case. We illustrate our results by several examples from population dynamics
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