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Effect of united expanding admixture on autogenous shrinkage and early age mechanical properties of high-strength engineered cementitious composites
No full textHigh-strength engineered cementitious composites (HS-ECCs) have garnered significant attention for their superior mechanical properties and ductility. However, their high autogenous shrinkage, caused by a low water-to-binder ratio, high cementitious content, and lack of coarse aggregate, often results in early-age cracking, limiting their broader use in civil engineering. Incorporating iron sand in HS-ECCs has enhanced their mechanical properties, reduced the carbon footprint, and moderately decreased shrinkage strain compared to traditional silica sand; however, the shrinkage strain remains substantial. This study aims to reduce the autogenous shrinkage of HS-ECCs further by incorporating united expanding admixtures (UEAs)—calcium oxide-based (CEA) and magnesium oxide-based (MEA) expansive agents—in varying amounts (3% to 10% by mass of cement). This study also examines the impact of these admixtures on the workability and mechanical properties of HS-ECCs. The results show that increasing the UEA content significantly reduces autogenous shrinkage strain, achieving a 40.66% reduction at 10% UEA, from 1007.31 με to 647.18 με. While higher UEA content decreases workability, as indicated by lower fluidity and penetration depth, the compressive strength remains largely unaffected. The tensile strength peaks at 12.38 MPa with 3% UEA but declines at higher contents, with higher UEA content effectively minimizing crack formation. The novelty of this research lies in the combined use of waste iron sand and UEA, optimizing the balance between workability, mechanical properties, and autogenous shrinkage reduction in HS-ECCs. These findings support the broader application of HS-ECCs in civil engineering projects requiring high mechanical properties and low shrinkage
Cannabinoids in integumentary wound care : a systematic review of emerging preclinical and clinical evidence
No full textThis systematic review critically evaluates preclinical and clinical data on the antibacterial and wound healing properties of cannabinoids in integument wounds. Comprehensive searches were conducted across multiple databases, including CINAHL, Cochrane library, Medline, Embase, PubMed, Web of Science, and LILACS, encompassing records up to May 22, 2024. Eighteen studies met the inclusion criteria. Eleven were animal studies, predominantly utilizing murine models (n = 10) and one equine model, involving 437 animals. The seven human studies ranged from case reports to randomized controlled trials, encompassing 92 participants aged six months to ninety years, with sample sizes varying from 1 to 69 patients. The studies examined the effects of various cannabinoid formulations, including combinations with other plant extracts, crude extracts, and purified and synthetic cannabis-based medications administered topically, intraperitoneally, orally, or sublingually. Four animal and three human studies reported complete wound closure. Hemp fruit oil extract, cannabidiol (CBD), and GP1a resulted in complete wound closure in twenty-three (range: 5–84) days with a healing rate of 66–86% within ten days in animal studies. One human study documented a wound healing rate of 3.3 cm2 over 30 days, while three studies on chronic, non-healing wounds reported an average healing time of 54 (21–150) days for 17 patients by oral oils with tetrahydrocannabinol (THC) and CBD and topical gels with THC, CBD, and terpenes. CBD and tetrahydrocannabidiol demonstrated significant potential in reducing bacterial loads in murine models. However, further high-quality research is imperative to fully elucidate the therapeutic potential of cannabinoids in the treatment of bacterial skin infections and wounds. Additionally, it is crucial to delineate the impact of medicinal cannabis on the various phases of wound healing. This study was registered in PROSPERO (CRD42021255413)
[In Press] Predictors of post-exercise affect : a self-determination theory approach considering physical, social, and psychological factors
No full textBackground: Studies have shown increases in affect after acute exercise. However, the specific aspects of an exercise experience that predict or contribute to post-exercise affect remain relatively unknown. This study aimed to determine which physical (i.e., duration and intensity), contextual (i.e., social context and time of day), and psychological factors (i.e., motivation and need satisfaction) predicted post-exercise affect. Methods: In 2021, 296 gym users self-reported affect before and immediately after exercising at a gym facility. Participants also reported situational motivation towards exercise, need satisfaction (i.e., autonomy, competence, and relatedness), who they exercised with (social interaction), and the duration and perceived intensity of their exercise session. We first conducted a paired samples t-test to identify whether affect significantly increased from before to after exercise, and then a hierarchical regression model to determine which factors predicted post-exercise affect. Results: Affect significantly increased from before to after exercise (t[291] = 8.116, p <.001). Autonomous motivation (β =.23, p = <.001), autonomy satisfaction (β =.15, p = <.05), and relatedness satisfaction (β =.19, p = <.01) significantly predicted post-exercise affect, whereas duration, perceived intensity, social interaction, and time of day did not. Conclusions: People should be encouraged to engage in activities that satisfy their need for autonomy and relatedness during leisure-time (i.e., not during the workday). So What?: This approach to physical activity promotion may lead to better affective outcomes and increased adherence compared to focusing on how long, how intense, or with whom people exercise
Health-related quality of life assessment in health economic analyses involving type 2 diabetes
No full textAim: Incorporating health-related quality of life (HRQoL) measures into health economic analyses can help to provide evidence to inform decisions about how to improve patient outcomes in the most cost-effective manner. The aim of this narrative review was to assess which HRQoL instruments have been used in economic evaluations of type 2 diabetes management including in Indigenous communities. Method: MEDLINE (Ovid), Embase (Ovid) and Cochrane were searched from inception to June 2022. Studies included patients with type 2 diabetes; economic evaluations, derived scores from direct questioning of individuals; and were in English. Records were assessed for bias using the JBI critical appraisal tools. Results: A total of 3737 records were identified, with 22 publications meeting the criteria for inclusion. Across those 22 articles, nine HRQoL instruments had been utilised. Generic tools were most frequently used to measure HRQoL, including EQ-5D (−3 L and −5 L) (n = 10, 38%); SF-12 (n = 5, 19%); and SF-36 (n = 4, 15%). Two tools addressing the specific stressors faced by people with type 2 diabetes were utilised: Problem Areas In Diabetes tool (n = 1, 4%) and Diabetes Distress Scale (n = 1, 4%). Two publications reported whether the study population included Indigenous peoples. Conclusion: A wide range of HRQoL instruments are used in economic evaluations of type 2 diabetes management, with the most frequent being varying forms of the EQ-5D. Few economic evaluations noted whether Indigenous peoples were featured in the study population. More research into HRQoL in people living with type 2 diabetes is urgently needed to improve evidence on effectiveness and cost-effectiveness of interventions
Twisted tape inserts in parabolic trough solar collectors : assessment of energy, exergy, and environmental impacts
No full textThe parabolic trough solar collector is a solar technology extensively employed to focus and harness solar energy for diverse heating purposes. One effective technique to enhance its thermal performance involves the insertion of swirl generators within its absorber tube. In this research, experimental investigation on performance enhancement of parabolic trough solar collector using single twisted tape and dual twisted tape insert across Reynolds number values ranging from 1,000 to 9,000 is performed. Collector efficiency, Nusselt number, friction factor, performance improvement factor, and exergy efficiency are examined for single twisted tape inserts with pitch to width ratios (y/w) of 1, 1.5, 2, 2.5, and 3, and dual twisted tape inserts with y/y0 ratios of 2, 3, and 4. Maximum enhancement in collector efficiency is reported at the lowest flow rate for both inserts. The single twisted tape insert with pitch to width ratio of 1 and the dual twisted tape insert with a pitch ratio of 2 exhibit the most notable enhancements in the evaluated performance parameters. Specifically, at lower flow rates (Re < 4400), the dual twisted tape insert (y/y0 = 2) outperforms the single twisted tape insert (y/w = 1). This dual twisted tape insert configuration provides a thermal efficiency enhancement of 14 %, while the Nusselt number and friction factor enhancement are found to be 372 % and 1600 % compared to bare tube. Additionally, the exergy efficiency exhibits a peak increase of 20.8 % at the lowest flow rate using the dual twisted tape insert (y/y0 = 2). This improvement translates to an annual CO2 reduction between 1.53 tons/year offering a highest enviro-economic benefit of 22.19 US dollars per year
Patient factors and health outcomes associated with illness perceptions in people with gout
No full textObjective: Illness perceptions are views and beliefs formed in response to a health threat, and they may influence self-management behaviours and chronic disease outcomes. Despite effective medication, sub-optimal outcomes in gout are common. This study aimed to quantitatively investigate illness perceptions in gout to examine how illness perceptions relate to health outcomes. Methods: Data were obtained from a randomized controlled trial in which people with gout (n ¼ 493) completed surveys measuring illness perceptions [Brief Illness Perception Questionnaire (B-IPQ)], gout flares, medication adherence, health-related quality of life, health-care utilization, and productivity, alongside serum urate blood tests at baseline, and at 6- and 12-month follow-ups. Multivariable linear regression identified patient factors independently associated with each B-IPQ item score. Logistic and linear regression, adjusted for age and sex, determined whether baseline B-IPQ items could predict current and future health outcomes. Results: Younger individuals and those with severe gout were more likely to experience pessimistic illness perceptions at baseline. Optimistic ill- ness perceptions were associated with lower odds of having had at least one flare in the preceding 6 months. Every 1-point increase in B-IPQ treatment control, indicating an increasingly optimistic view that gout is treatable, decreased the odds of a recent flare prior to baseline by 33% [odds ratio (OR): 0.67; 95% CI: 0.53, 0.85; P < 0.001] and prior to the 12-month follow-up by 15% (OR: 0.85; 95% CI: 0.76,0.96; P ¼ 0.01). Pessimistic illness perceptions also predicted poorer medication adherence, health-related quality of life, and productivity, but not serum urate levels. Conclusion: Modifying pessimistic illness perceptions, including, but not limited to, patient education, may promote prudent self-management behaviours and better outcomes in gout
Clinical outcomes in people with diabetes-related foot infections : analysis from a limb preservation service infection database
No full textBackground: Diabetes-related foot infections are common and represent a significant clinical challenge. There are scant data about outcomes from large cohorts. The purpose of this study was to report clinical outcomes from a large cohort of people with diabetes-related foot infections. Methods: A tertiary referral hospital limb preservation service database was established in 2018, and all new episodes of foot infections were captured prospectively using an electronic database (REDCap). People with foot infections between January 2018 and May 2023, for whom complete data were available on infection episodes, were included. Infection outcomes were compared between skin and soft tissue infections (SST-DFI) and osteomyelitis (OM) using chi-square tests. Results: Data extraction identified 647 complete DFI episodes in 397 patients. The data set was divided into two cohorts identifying each infection episode and its severity as either SST-DFI (N = 326, 50%) or OM (N = 321, 50%). Most infection presentations were classified as being moderate (PEDIS 3 = 327, 51%), with 36% mild (PEDIS 2 = 239) and 13% severe (PEDIS 4 = 81). Infection resolution occurred in 69% (n = 449) of episodes with failure in 31% (n = 198). Infection failures were more common with OM than SST-DFI (OM = 140, 71% vs. SST-DFI = 58, 29%, p < 0.00001). In patients with SST-DFI a greater number of infection failures were observed in the presence of peripheral arterial disease (PAD) compared to the patients without PAD (failure occurred in 30% (31/103) of episodes with PAD and 12% (27/223) of episodes without PAD; p < 0.001). In contrast, the number of observed infection failures in OM episodes were similar in patients with and without PAD (failure occurred in 45% (57/128) of episodes with PAD and 55% (83/193) of episodes without PAD; p = 0.78). Conclusions: This study provides important epidemiological data on the risk of poor outcomes for DFI and factors associated with poor outcomes in an Australian setting. It highlights the association of PAD and treatment failure, reinforcing the need for early intervention to improve PAD in patients with DFI. Future randomised trials should assess the benefits of revascularisation and surgery in people with DFI and particularly those with OM where outcomes are worse
[In Press] SME supply chain resilience in disruptive times : the effects of supply chain robustness, access to government assistance and disruption intensity
No full textPurpose – This study investigates the antecedents of supply chain resilience of small and medium-sized enterprises (SMEs) and the effects of government assistance and disruption intensity in long-term disruptions. Design/methodology/approach – This study collected data from 626 SMEs in Australia in 2022 and analysed data using partial least squares structural equation modelling. Findings – The study empirically confirms that digital capabilities, prior experience in disruptions, supplier proximity and relationships are antecedents of supply chain resilience of SMEs, with supply chain robustness as a mediator. It further confirms that SMEs’ access to government assistance positively moderates the relationship between digital capabilities and supply chain robustness. The disruption intensity moderates the relationships between supplier proximity and supply chain robustness with supply chain resilience. Severe disruptions weaken the effects of prior disruption experiences and supplier relationships on supply chain resilience. Practical implications – The findings inform SME practitioners of the importance of building supply chain robustness, leveraging their prior experience, supplier proximity and relationships and capabilities and flexibility for dynamic supply chain structures when disruptions are intense. Originality/value – The novelty of our study is the use of the Contingent Resource-Based View to understand the effects of firm and supply chain-level antecedents on supply chain robustness and resilience, considering the contextual contingencies of disruption intensity and government assistance. The focus on long-term disruptions extends the conventional supply chain resilience studies on supply and demand disruptions of small scale. We also explore the firm-level effects of government assistance, which extends the commonly tested economic-level effects. Furthermore, we investigate supply chain robustness and resilience as different but connected constructs, deviating from common approaches. The finding that the relationship between digital capabilities and supply chain robustness, not the relationship between digital capabilities and supply chain resilience, becomes stronger with higher access to government support shows the importance of this approach to investigating specific effects
Teaching and researching the world in South Africa
No full textThis reflective article offers an argument for the importance of making international connections for historical research regardless of where one is based. For students in South Africa to gain further knowledge of the world, universities in the field of history need to offer global coverage in subject offerings and research strengths. The National Research Foundation in South Africa offers tremendous help in this regard through research funding calibrated to publication output. The challenge is less that an historian who specializes on history outside South African history faces limitations but rather that those faculty will have challenges recruiting students who are not narrowly focused on South African history to the exclusion of other regions of Africa and the globe. Since the best universities in the world strive for global coverage of topics a winning strategy would be for universities in South Africa to do the same. The SAHJ plays a vital role in solving this dilemma. This article argues that the SAHJ should build on its impressive focus on South African history while casting at the same time a broader net, offering history faculty and students in South Africa the resource of scholarship that emphasizes South Africa's global connections and influence on the world
Exploratory factor analysis for willingness to accept social robot recommendations scale
No full textThe paper discusses exploratory factor analysis of Willingness to Accept Social Robot Recommendations (WASRR) in a hospitality setting. The first four stages of the scale development will be discussed: literature review, thesaurus search, expert panel interviews and exploratory factor analysis. The study will adopt Churchill (1979) and Devillis (1991) to develop the scale, which will provide a diagnostic assessment of social robot recommendations