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Submolecular insights into the adsorption mechanism of imidazolium-based corrosion inhibitors: A novel quantum parameter for predicting inhibition superiority
Get PDFDespite extensive research, there are still debates about distinct aspects of corrosion inhibition by organic inhibitors. In this study, two novel ionic liquids (ILs) were synthesized and investigated as model inhibitors for mild steel in 0.5 M HCl. Electrochemical methods and surface characterization through FTIR, XPS, and FE-SEM, along with thermodynamic and first-principles calculations, were employed to evaluate inhibition efficacy and to unravel the underlying mechanism. Results revealed that, following a one-layer adsorption isotherm, the ILs predominantly exhibited anodic spontaneous physicochemical interactions with the corroding substrate. As a result, at least 84 % of the acidic corrosion was mitigated using 4 mM of the ILs, according to impedance studies. Furthermore, chloride-mediated cooperative (indirect) adsorption, apart from direct surface binding, was confirmed experimentally for the first time, providing better justification for the dominant anodic performance. Utilizing quantum calculations, it was demonstrated how the data computed for standalone inhibitors can contribute to estimate the most stable adsorption configurations. In addition, the role of each functional group and atomic constituent in the adsorptive corrosion inhibition was elaborated, given different possible adsorbate-adsorbent interaction modes. Finally, a novel quantum parameter was introduced, and its potential application as an indicator for identifying superior corrosion inhibition was described
A psychometric study of the Flourishing Scale for people living with dementia
Get PDFINTRODUCTION There are few validated strengths-based outcome measures for evaluations of psychosocial interventions in dementia and measurement of the concept of flourishing has not been directly explored. This study therefore examined the psychometric properties of the Flourishing Scale (FS)—an eight-item generic self-report measure of social-psychological well-being—and how it might be adapted for people with dementia. METHOD A secondary data analysis of baseline data from the Journeying Through Dementia study, a randomized controlled trial of a self-management intervention for older adults with dementia living in the community in the United Kingdom (n = 480). Confirmatory Factor Analysis (CFA), Item Response Theory (IRT) analyses, and convergent/discriminatory analyses were undertaken. RESULTS Moderate negative skew in total FS scores was noted and adjusted for. A good level of internal consistency reliability was evident (alpha = 0.83). Both CFA and IRT analyses verified the unidimensionality of the scale and there was evidence of item discrimination. Measurement precision appeared greater for lower to moderate levels of well-being, with some item-level variation. Total FS scores were significantly associated with quality of life, self-efficacy, and mood, supporting convergent validity. FS total scores were not associated with cognitive ability or time since diagnosis in this sample but were associated with living alone / with others. DISCUSSION These findings offer new avenues for strengths-based research and practice of psychosocial interventions for people with dementia in relation to the measurement social-psychological well-being. The FS shows promise as a valid and reliable self-report instrument for people with early-stage dementia but further validation research is needed to confirm optimum item content and responsiveness. The measurement of well-being of people living with moderate to severe cognitive impairments requires further research. Highlights Previous work suggests that well-being in dementia could align with the concept of flourishing—optimized social-psychological well-being—but valid and reliable measurement of flourishing in dementia has not yet been directly explored. The aim of this study was to investigate the psychometric properties of the Flourishing Scale, a brief measure of social-psychological well-being previously validated with older people and cross-culturally, for people living with dementia. We carried out a secondary analysis of baseline data (n = 480) from a previous randomized controlled trial of a self-management psycho-social intervention in dementia (the Journeying Through Dementia trial). Participants were living with early-stage dementia, were predominantly White/British, and 57.8% were male. We utilized Classical Test Theory and Item Response Theory methods to examine the reliability, uni-dimensionality, and validity of the Flourishing Scale as well as item characteristics. Findings indicate the Flourishing Scale is uni-dimensional and has adequate internal consistency and validity for measuring social-psychological well-being in dementia. The scale can discriminate between different levels of well-being in dementia, particularly at lower to moderate levels. Items concerned with active engagement appear most sensitive to measured levels of flourishing overall. People with dementia living alone may be most at risk of lower levels of social-psychological well-being. Levels of flourishing were not correlated with cognitive impairment. The Flourishing Scale measures eudaimonic dimensions of well-being and may be of value in future dementia studies focused on these. The measurement precision of the Flourishing Scale for people with dementia may be best at low-moderate levels and items may vary somewhat in terms of ability to discriminate levels of well-being. Further research should explore optimum item content and response format and investigate how reliable and valid the instrument is longitudinally and for people living with a range of cognitive impairments at different stages of dementia
High yield methane production from the hydrogenation of CO₂ using non-thermal plasma/catalysis
Get PDFIn this work, a dielectric barrier discharge (DBD) non-thermal plasma/catalytic reactor was used under a range of process conditions, designed to maximise the hydrogenation of CO₂ to methane. A Ni/Al₂O₃ catalyst was used in the plasma/catalysis reactor and the process parameters investigated were the effect of input plasma power, catalyst temperature, catalyst weight hourly space velocity (WHSV), and H₂/CO₂ ratio in relation to the methanation of CO₂. In addition, the effect of the catalyst active metal type (ruthenium, cobalt, and lanthanum) supported on Al₂O₃ under the optimum reaction conditions was investigated. The optimised system, using Ni/Al2O3, achieved a CO₂ conversion of 82.2 % with an energy efficiency of 22.5 gCO₂kWh−1, CH₄ selectivity of 90.2 % and energy efficiency of 7.4 gCH₄kWh−1 at the plasma input power of 70 W, catalyst temperature of 280 °C, catalyst WHSV of 768 ml/gcath, and H₂/CO₂ ratio of 4. The performance of the active catalyst metals in relation to CO₂ conversion to methane was Ru > Ni > Co > La
Catalytic conversion of biomass components and waste biomass for hydrogen/syngas production using biochar catalysts
Get PDFBiochar produced from the pyrolysis of waste biomass (sawdust) was used as a catalyst in the two-stage, pyrolysis-catalytic steam reforming of biomass components and waste biomass in a two-stage fixed bed reactor. The thermal degradation characteristics of cellulose, hemicellulose and lignin as representative biomass components and waste biomass were determined by thermogravimetric analysis. In addition, potassium and calcium metal salts were added to a mixture of the three biomass components to investigate the effect of the alkali and alkaline earth metals on the process. The results showed that among the three main components, the pyrolysis-catalytic steam reforming of lignin produced the highest hydrogen and syngas yields in the presence of biochar catalyst. Mixing cellulose, hemicellulose and lignin produced a synergistic effect in the pyrolysis-catalytic steam reforming process, significantly promoting hydrogen release. Adding K and Ca metals to the biomass component mixture further increased the hydrogen and carbon monoxide yields. The product yield from pyrolysis-catalytic steam reforming of the waste biomass indicated that the process for real biomass is not a simple superposition of individual components, highlighting the complexity of real biomass systems. The proposed mechanism of pyrolysis catalytic steam reforming demonstrated the unique role of biochar, including its self-gasification, which significantly contributed to hydrogen and syngas production. This study not only underscores the synergistic effects in co-pyrolysis but also reveals the practical potential of biochar as a sacrificial catalyst for efficient hydrogen production
Co-designing and testing the learn together guidance to support patient and family involvement in patient safety investigations: a mixed-methods study.
Get PDFBackground
There are multiple reasons for involving patients and families in incident investigations. Fiscally, costs due to clinical negligence claims approximate £4 billion annually. Logically, patients and families provide important information about patient safety incidents. Morally, involving harmed patients and families helps address their concerns. However, little United Kingdom-based evidence was available to support systematic involvement.
Objective
To co-design processes and resources to guide the involvement of patients and families in incident investigations at a national and local level, and to test these processes to understand their impact upon experience, learning and likelihood of litigation.
Design and methods
A mixed-methods programme of research was undertaken. Stage 1 comprised a scoping review of evidence for the experience of patients/families in incident investigations, and a documentary analysis of 43 National Health Service Trust incident investigation policies. Stage 2A extended this with 41 qualitative interviews with patients/families, healthcare staff and investigators. Stage 2B synthesised previous data to develop common principles and programme theory. Stage 3 involved a 6-month co-design phase with a ‘co-design community’ of > 50 stakeholders. In stages 4 and 5, co-designed guidance was evaluated in a 15-month ethnography, within four National Health Service Trusts and the national independent investigatory body. Twenty-nine investigations were followed in real time, including 127 interviews and 45 hours of observation. Four final co-design workshops supported iterations to the final guidance and website. A substudy explored meaningful involvement in, and learning from, investigations following suicide via interviews and a qualitative survey involving 32 people (healthcare staff, policy-makers and managers; people bereaved by suicide).
Findings
Stage 1 found stakeholders valued involvement, but it was not well supported by local policy, even though it likely reduces litigation. Stage 2A found a need for navigational support, and support for other needs. In stage 2B, 10 common principles and a programme theory were developed, emphasising the aim of reducing compounded harm, alongside promoting organisational learning. In stage 3, four draft guidance booklets and a training session were developed. Stage 4 found these to be feasible, with stakeholders positive about involvement, and generally agreed that it aided organisational learning. The guidance supported systematisation of involvement and encouraged relational working, but wider organisational challenges were highlighted. The substudy found that suicide was regarded as somewhat different to other safety events. Meaningful involvement was complicated by a range of factors and should be decoupled from postvention support.
Limitations
Undertaking research during the pandemic may have impacted sample representativeness in stage 2A. Ethnically minoritised and lower socioeconomic groups were under-represented across the programme.
Future research
Research should explore how people from minoritised groups experience investigations and any required adaptations to the approach. Research should also explore the possibilities for ‘harm-centred’ rather than ‘incident-centred’ responses to safety.
Conclusions
Investigations are complex, relational processes. Our guidance was found to be feasible, with stakeholders being positive about involvement and the impact on organisational learning. It may help to reduce the significant and long-lasting experience of compounded harm for patients and families. However, involvement may always be challenging due to the divergent needs of patients/families and organisations
Factors associated with the school exclusion gap for children with social work involvement: a retrospective cohort study using national administrative data
Get PDFChildren who receive social care services are known to have higher exclusion rates than those without social care involvement. However, there is limited evidence on which groups of children are most at risk of this exclusion gap. This article reports on a retrospective analysis of administrative data from the National Pupil Database in England, covering two age-based cohorts of children (n = 1.2 million) who took standardized tests in 2019. Children receiving social care services within the previous five years were compared with those with no social care involvement, focusing on rates of exclusion within a 12 month period. Regression models were estimated to examine how the relative likelihood of exclusion was associated with a range of covariates, including demographic characteristics, special educational needs and disabilities, categories of social care need, and various aspects of provision. Results showed that the gap in exclusions was wider for children with multiple episodes of social care involvement, some—but not all—types of special educational needs and disabilities, and for certain categories of social care needs. Implications for policy and practice are discussed, particularly with respect to children with behavioural difficulties
Computational fluid dynamics and shape analysis enhance aneurysm rupture risk stratification
Get PDFPurpose
Accurately quantifying the rupture risk of unruptured intracranial aneurysms (UIAs) is crucial for guiding treatment decisions and remains an unmet clinical challenge. Computational Flow Dynamics and morphological measurements have been shown to differ between ruptured and unruptured aneurysms. It is not clear if these provide any additional information above routinely available clinical observations or not. Therefore, this study investigates whether incorporating image-derived features into the established PHASES score can improve the classification of aneurysm rupture status.
Methods
A cross-sectional dataset of 170 patients (78 with ruptured aneurysm) was used. Computational fluid dynamics (CFD) and shape analysis were performed on patients’ images to extract additional features. These derived features were combined with PHASES variables to develop five ridge constrained logistic regression models for classifying the aneurysm rupture status. Correlation analysis and principal component analysis were employed for image-derived feature reduction. The dataset was split into training and validation subsets, and a ten-fold cross validation strategy with grid search optimisation and bootstrap resampling was adopted for determining the models’ coefficients. Models’ performances were evaluated using the area under the receiver operating characteristic curve (AUC).
Results
The logistic regression model based solely on PHASES achieved AUC of 0.63. All models incorporating derived features from CFD and shape analysis demonstrated improved performance, reaching an AUC of 0.71. Non-sphericity index (shape variable) and maximum oscillatory shear index (CFD variable) were the strongest predictors of a ruptured status.
Conclusion
This study demonstrates the benefits of integrating image-based fluid dynamics and shape analysis with clinical data for improving the classification accuracy of aneurysm rupture status. Further evaluation using longitudinal data is needed to assess the potential for clinical integration
Hierarchical political power and the value of cash holdings
Get PDFThis study examines the relationship between hierarchical political power and the value of cash holdings. To model the power structure, we utilize the hierarchical civil service system in China to distinguish between the holders of high- and low-level political power. We establish that directors with high-level political power increase the market value of cash, whereas those with low-level political power have no impact. Such effects are more pronounced in non-state-owned firms, in regions where politicians are subject to higher political pressure and in firms experiencing stronger agency conflicts. Further analysis shows that directors with high-level political power can increase the value of cash holdings through improved investment efficiency. Among directors with high-level political power, shareholders benefit most from the presence of those ranked at the Bureau-Department level. Our study provides original evidence that political hierarchy holds significance for investors’ valuation of cash holdings and emphasizes the importance of the heterogeneous nature of boards’ political capital in determining corporate value
Association between clinical outcomes and MRI-detected imaging findings for people with midfoot pain, a cross-sectional study
Get PDFBackground
Midfoot pain is common but poorly understood, with radiographs often indicating no anomalies. This study aimed to describe bone, joint and soft tissue changes and to explore associations between MRI-detected abnormalities and clinical symptoms (pain and disability) in a group of adults with midfoot pain, but who were radiographically negative for osteoarthritis.
Methods
Community-based participants with midfoot pain underwent an MRI scan of one foot and scored semi-quantitatively using the Foot OsteoArthritis MRI Score (FOAMRIS). Foot pain and disability were recorded using visual analog scales (VAS) and the Modified-Manchester Foot Pain Disability Index (MMFPDI). Associations were assessed for continuous data using Spearman’s Rho, and for categorical data, a Wilcoxon signed rank test. Linear regression was used to explore the association between participant-reported measures and MRI abnormalities, adjusted for age, sex and BMI.
Results
Sixty-one participants (70% female, mean age 48.5 years, median BMI 28.6 kg/m2) were included. Median VAS pain was 31/100 mm (IQR 21–47) and median disability was 30/48 (IQR 26–36). There was a moderate association between midfoot pain severity and the number of joints exhibiting joint space narrowing; adjusted results suggested 31% (95% confidence interval 3%–68%) worse VAS pain with each additional affected joint. Greater numbers of joints with cysts were associated with worse VAS pain [14% (0%–31%)] and disability [1.1 units (0–2.2)]. Effusion/synovitis was associated with MMFPDI pain. No other MRI abnormalities were associated with sex, body mass and foot pain/disability measures. Bone marrow lesions, joint space narrowing, cysts and osteophytes occurred more frequently with age. MRI abnormalities were common, particularly in the talo-navicular joint, first and second cuneo-metatarsal joints. Those with dorsal foot pain had more multi-joint involvement, bone marrow lesions, joint space narrowing and cysts and for those with pain on midfoot movement, bone marrow lesions and cysts were reported.
Conclusions
In people with midfoot pain, MRI-detected features of osteoarthritis and soft-tissue abnormalities were found, clustered in the medial and intermediate cuneiform joints. These features were more common with age but not associated with pain or disability measures. Younger people with dorsal midfoot pain exhibited early signs of bone and joint features of osteoarthritis and we recommend further imaging studies to determine the clinical and diagnostic significance
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