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Previous studies have indicated that hydratable magnesium carboxylate (HMC) exhibits potential as an MgO‐based binder, but its limited medium‐temperature strength has hindered its widespread industrial application. In this study, the incorporation of MgO fumes into castables is intended to react with microsilica to form magnesium–silicate–hydrate (M–S–H), and the synergistic effect of HMC and M–S–H is anticipated to improve the mechanical properties of castables at intermediate temperatures. The effects of MgO fumes on the properties of HMC‐bonded castables were comprehensively investigated. The results demonstrate that incorporating MgO fumes into castable serves multiple functions. The ionized MgOH+ from MgO fumes hinders the hydration process of HMC, prolonging the final setting time from 13 to 98 min and improving the workability of castables. The incorporation of MC‐1100 enhanced mechanical properties at medium temperature due to the synergistic effects of brucite, HMC, and M–S–H. Specifically, the CMOR increased 20% after sintering at 800°C. Furthermore, adding MC‐1100 increases the residual strength rate of castable by 10% compared to those without MgO fumes. This can be attributed to enhanced spinel formation resulting from adding MgO fumes that improves elastic modulus and reduces elastic strain energy generation during thermal shock, thus increasing crack propagation resistance. [ABSTRACT FROM AUTHOR]

In order to reduce carbon emissions,MgO-C refractories were prepared using fused magnesia, flake graphite,Al-Si composite powder and a-AI2O3 micropowder as raw materials,and new environmental friendly complex magnesium-aluminum cementing agent (abbreviated as W powder) and phenolic resin (abbreviated as PF) as binders, respectively. The physical properties and thermal shock resistance of the MgO-C refractories were compared. The results show that: (1) after different temperature treatment, W powder bonded samples have higher linear change rate and apparent porosity but lower bulk density and cold compressive strength than PF bonded samples; (2) W bonded samples have better thermal shock resistance than PF bonded samples, and the cold modulus of rupture of the sample bonded with W after one thermal shock is increased by 19.2%. [ABSTRACT FROM AUTHOR]

High temperature alloys are an important guarantee for the development of aviation engines and gas turbines. Precision casting is the main technology for manufacturing high-temperature alloy castings. Due to the severe working conditions, such as high temperature, high vacuum and frequent temperature fluctuation as well as the existence of active metal elements in high-temperature alloys, high requirements to crucibles for casting are needed. There are many types of crucibles for precision casting of high-temperature alloys, showing different application problems. Crucibles made of different materials for precision casting of high-temperature alloys and their research status were summarized. The research direction of crucibles for precision casting of high-quality high-temperature alloys was prospected. [ABSTRACT FROM AUTHOR]

Dry skin and pressure injuries in older persons have become global health care problems. This was a multicentre, prospective cross‐sectional study in 44 hospitals and 8 long term care institutions from 20 provinces, autonomous regions and municipalities in China and aimed to explore the relationship between the two skin problems in older patients. We mainly found 11 602 cases with dry skin and 1076 cases with pressure injuries in a total of 33 769 valid participants. The overall prevalence of dry skin and pressure injuries was 34.4% (95% confidence interval [CI] 33.9–34.9) and 3.1% (95% CI 2.9–3.3). Stage 2+ pressure injuries were the most (32.9%), followed by stage 1 (32.4%). The patients with dry skin had more pressure injuries than ones without dry skin (50.0% vs 33.9%). The patients with very severe and severe dry skin had more pressure injury risk (OR 2.22 and 1.90) and more stage 2+ pressure injury risk (OR 2.83 and 1.63). Other nine predictors associated with overall pressure injuries and stage 2+ pressure injuries. The area under receiver operating characteristic (ROC) curve of the predictive models of overall pressure injuries and stage 2+ pressure injuries were 0.89 (95% CI 0.88–0.90) and 0.91 (95% CI 0.90–0.92), respectively. [ABSTRACT FROM AUTHOR]