Weakness Research Articles

Study on sewage erosion resistance of nano titanium modified coral concrete

Sewage environments can significantly erode and degrade coral concrete, impacting its structural longevity. Moreover, the curing water environment greatly influences coral concrete's resistance to sewage erosion. This study investigated the modification of coral concrete with nano TiO2 to enhance its sewage erosion resistance. Concrete specimens with four different mass fractions of nano TiO2 were prepared and cured in three environments. Tests for compressive strength, flexural strength, and mass loss were conducted before and after 180 days of sewage exposure, and a corrosion coefficient was defined to evaluate resistance to sewage corrosion. While nano TiO2 significantly improved the mechanical properties and sewage erosion resistance of coral concrete, oxalic acid and seawater environments had adverse effects. Furthermore, increasing the nano TiO2 mass fraction initially enhanced and then reduced strength and resistance, while mass loss rates first decreased and then increased. The optimal nano TiO2 dosage of 4% resulted in a maximum increase of 22.2% in compressive strength, 33.2% in flexural strength, a 0.06 increase in the compressive corrosion resistance coefficient, and a 0.1 increase in the flexural corrosion resistance coefficient. At this dosage, compressive strengths of coral concrete cured in oxalic acid and seawater were 97.8% and 93.9% of those in freshwater, while flexural strengths were 97.8% and 94.4%, respectively, with slight decreases in corrosion resistance coefficients, accompanied by higher mass loss rates. X-ray diffraction (XRD) and scanning electron microscopy (SEM) revealed that nano TiO2 promotes cement hydration, forming a dense structure by filling matrix pores. However, oxalic acid reacts with Ca(OH)2 to form calcium oxalate, slowing cement hydration, while MgCl2 in seawater reacts with Ca(OH)2, forming expansive Mg(OH)2, which increases internal concrete pores.

Modification of the polymeric admixture based on polycarboxylate ether using silica-derived secondary materials obtained from fly ash and the efficiency of its application in concrete

The rising energy prices and the costs of CO2 emissions into the atmosphere are forcing the construction industry to search for ways to reduce cement consumption in concrete technology by optimizing concrete mixtures and making greater use of chemical admixtures. The scientific problem lies in understanding how polymers modified with silica-derived secondary materials, such as those obtained from fly ash (e.g., synthetic zeolites, mesoporous silica), interact with the concrete matrix and influence their durability and strength. The present study investigated the effect of a polymeric admixture based on polycarboxylic ether (PCE) modified with silica-derived secondary materials obtained from fly ash (synthetic zeolites, mesoporous silica) on the physical and mechanical properties of concrete. The study considered the effect of the modified polymer admixture dosed in 3 different amounts (0.4%, 0.8% and 1.2%) by weight of cement on the fresh properties of the concrete mixture, i.e. consistency and air content. The research scope also included determining the physico-mechanical properties of the concretes and investigating the effect of the modified admixture on the frost durability of the cement composite. In order to study the modification of the concrete microstructure, XRD phase analysis and air pore structure analysis by MIP were carried out. The study showed an increase in compressive strength after 28 days of curing in concretes containing the modified polymer of about 8-12% compared to the reference concrete. In addition, it was observed that strength increased with increasing admixture dosage. The resulting pore structure, contributed to improving the frost resistance of the concretes by reducing compressive strength loss from about 14% in reference concretes to about 2-9% in concretes with the modified polymer after 150 cycles of alternating freeze-thaw. At the same time, it was observed that the use of the modified polymer resulted in an increase in weight absorption from 2% do 4.5%, a more than twofold increase in depth of penetration of water under pressure and a more than 70% increased total porosity. In conclusion, the polymer-modified MCM-41 can positively affect the mechanical and durability properties of concrete, but it causes a change in the pore structure, which could have a negative effect on water absorption and total porosity.

Mechanical Behavior of Origami-Based Inflatable Bistable Foldable Panels

Abstract Deployable structures are extensively used in engineering. A bistable panel structure, inspired by multistable origami, is proposed, capable of deployment and folding powered by air pressure. Prototypes were manufactured using planar laser etching technology based on geometric design. Mechanical behavior under out-of-plane compression, in-plane compression, and out-of-plane bending loads was analyzed through experiments. The foldable panel showed superior mechanical performance under out-of-plane compression, highlighting its potential as an ideal energy-absorbing material. In-plane compression and out-of-plane bending along the folding direction exhibited lower strength due to foldability, with failure modes involving rigidity loss from folding. The structure demonstrated good energy absorption characteristics during in-plane compression. As the angle of the unit increased during out-of-plane bending, mechanical performance improved, but the failure mode shifted to fracture. In in-plane compression and out-of-plane bending perpendicular to the folding direction, mechanical performance was enhanced, but the structure failed due to strength loss from fracture.

Current approach to the diagnosis of sarcopenia in cardiovascular diseases

Muscle wasting syndrome, also known as sarcopenia, is an age-related geriatric condition characterized by a gradual loss of muscle mass, strength, and function. Sarcopenia can be classified into primary and secondary types. Primary sarcopenia is primarily associated with aging, while secondary sarcopenia is caused by systemic diseases such as cancer, diabetes, liver cirrhosis, musculoskeletal disorders, and disuse changes. In recent years, increasing evidence suggests that cardiovascular diseases can promote the occurrence of sarcopenia through various pathophysiological mechanisms. Additionally, sarcopenia increases the risk of adverse outcomes in patients with cardiovascular disease such as rehospitalization and mortality. Therefore, screening and diagnosing sarcopenia are particularly important for patients with cardiovascular diseases. This article provides a brief overview of the research progress on diagnostic methods for sarcopenia in patients with cardiovascular diseases.

Impact of geopolymer aggregate on the mechanical properties and durability characteristics of concrete

This study examined the use of geopolymer aggregate (GPA), produced from slag and an alkaline solution, as a substitute for coarse aggregate in conventional concrete. The research aimed to evaluate how different proportions of GPA (25%, 50%, 75%, and 100% replacement) affect the durability and mechanical properties of concrete. A series of tests were conducted, including slump, compressive strength, flexural strength, chloride resistance, sulfate resistance, sorptivity, and water absorption. The results demonstrated significant improvements in concrete properties with the inclusion of GPA. The compressive strength of GPA concrete ranged from 31 to 38 MPa, showing a 10%–15% increase over that of standard concrete. Flexural strength improved by 6% at 7 days and 7.5% at 28 days compared to control mixes. Water absorption was reduced by 42.58%, and sorptivity decreased by 47.9% compared to ordinary aggregate concrete. GPA concrete also excelled in acid resistance, with a weight loss of 28.6% and a lower reduction in strength compared to traditional acidic aggregates. In sulfate resistance tests, GPA concrete showed a 31% reduction in both weight and strength loss. These results highlight the advantages of using GPA as an alternative to conventional coarse aggregates. GPA not only enhances the mechanical and durability properties of concrete but also presents a more sustainable option, contributing to reduced environmental impacts associated with traditional aggregate materials.

Association between sarcopenia and the foot-ankle function in type 2 diabetic foot ulcer.

The diabetic foot (DF) ulcer is the severe complication of type 2 diabetes mellitus (T2DM). Sarcopenia is characterized as the loss of muscle mass and strength, resulting in the increased risk of fracture and physical disability. Sarcopenia may affect the foot-ankle function in DF ulcer patients, compromise the quality of life. The aim was to clarify the effect of sarcopenia on foot-ankle function in patients with DF ulcer. In total of 108 T2DM patients with DF ulcer were enrolled. Based on the examination of muscle mass by dual energy X-ray absorptiometry (DXA) and grip strength and 5x sit-to-stand test, the DF patients were divided into sarcopenia and non-sarcopenia groups. The severity of DF ulcer was evaluated by Wagner classification. The foot-ankle function was evaluated by American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Score. DF patients with sarcopenia showed advanced age, lower BMI, longer duration of T2DM, and more severe Wagner classification, reduced appendicular skeletal muscle mass index (ASMI), grip strength, transcutaneous oxygenpressure (TcPO2) and prolonged time of 5X sit-to-stand test. The stratified comparison analysis indicated that severity of sarcopenia and DF ulcer, reduced TcPO2, and grip strength were aggravated with the impaired foot-ankle function (P < 0.05). Multivariate Logistic analysis showed that age, TcPO2, and severe sarcopenia were risk factors deteriorating the foot-ankle function. The sarcopenia is a key risk factor of decreasing foot-ankle function in patients with DF ulcer. Thus, the prevention of muscle mass and strength loss could be considered as part of comprehensive therapy for DF ulcer.

Methods for assessing the self-healing properties of asphalt concrete

The article presents the results of a study of the ability of asphalt concrete to independently restore the state of the structure or improve the operational state of the material. The quality indicators that reflect the degree of efficiency of the developed self-healing technology are: the degree of restoration of the operational state of the structure; timeliness of initiation of the self-healing process; the speed of the restoration process, as well as the durability of the operational state after self-healing. The article formulates requirements for new methods for testing the self-healing ability of materials with encapsulated modifiers. It is shown that the self-healing efficiency is significantly higher for asphalt concretes with encapsulated AR polymer than for SMA, which used encapsulated oil. With the optimal content of encapsulated oil, the loss of strength of asphalt concrete samples during repeated compression is 1.4 times less, and for encapsulated AR polymer it is 1.6–2.1 times less. For SMA with encapsulated oil, the failure rate is 1.05, and with encapsulated AR polymer 1.7. The coefficient values reflect that the achievement of the critical value of the strength limit for asphalt concrete with encapsulated AR polymer occurs later by 61.9% than for asphalt concrete with encapsulated oil. The speed of the self-healing process of asphalt concrete using encapsulated oil is 10% faster than asphalt concrete without capsules, and with the use of encapsulated AR polymer – by 23%.

Performance Research and Engineering Application of Fiber-Reinforced Lightweight Aggregate Concrete

Low strength and low impact toughness are two of the main issues affecting the use of lightweight aggregate concrete in harsh cold environments. In this study, the strength of concrete was improved by adding high-strength fibers to bear tensile stress and organize crack propagation. Four sets of comparative experiments were designed with freeze–thaw cycles of 0, 50, 100, and 150 to study the mechanical properties of fiber-reinforced lightweight aggregate concrete under freeze–thaw conditions. A detailed study was conducted on the effects of freeze–thaw on the compressive strength, flexural strength, impact toughness, and microstructure of concrete with different fiber contents (3, 6, and 9 kg/m3). The results show that for ordinary lightweight aggregate concrete, under the freeze–thaw cycle, the internal pore water of the concrete froze and generated expansion stress, resulting in tensile cracks inside the concrete. The cracks gradually accumulated and expanded, ultimately leading to cracking and damage of concrete structures. After 150 cycles, the strength loss rate exceeded 25%. When adding a reasonable amount of fiber (6 kg/m3), the fiber took on the tensile stress and hindered the development of internal cracks, significantly enhancing the splitting tensile strength, flexural strength, and impact toughness of lightweight aggregate concrete. And the failure pattern of concrete was significantly improved. At the beginning of the freeze–thaw cycle, the internal tensile stress was less than the fiber tensile strength and the fiber–matrix bonding strength, and the strength reduction rate of the concrete was slow. Relying on the friction absorption capacity between the fiber and the matrix, the fiber used its own deformation to resist the tensile stress. In the late stage of the freeze–thaw cycle, due to the destruction of the fiber–matrix transition zone structure, the bond strength decreased, the crack resistance and toughening effect decreased, and the strength of the concrete decreased rapidly. Moreover, the reduction in impact toughness was greater than the compressive strength and flexural strength under static load.

Effect of nano‐SiO2 dispersion on the mechanical properties and frost resistance of modified cement paste

AbstractThe dispersion of nano‐SiO2 (NS) in cement plays a critical role in enhancing the properties of cementitious materials. In this study, the combination of ultrasonic dispersion and polycarboxylic acid water reducing agent (PCE) was used to significantly improve the dispersion of NS. The effects of ultrasonic dispersion time, NS content, and PCE content on dispersion quality were investigated, alongside their impact on mechanical properties, electrical resistivity, and frost resistance. The results demonstrated that this synergistic method optimized the dispersion of NS, leading to superior mechanical properties and frost resistance. With an ultrasonic dispersion time of 40 min, NS content of 1.0 wt.%, and PCE content of 0.75 wt.%, the cement paste achieved its optimal performance. Compared to non‐dispersed samples, compressive strength increased by 33.7%. After 75 freeze–thaw cycles, the mass loss was 2%, the relative dynamic elastic modulus was 99.15%, and the strength loss was 13.74%.

Nicotinamide and pyridoxine stimulate muscle stem cell expansion and enhance regenerative capacity during aging.

Skeletal muscle relies on resident muscle stem cells (MuSCs) for growth and repair. Aging and muscle diseases impair MuSC function, leading to stem cell exhaustion and regenerative decline that contribute to the progressive loss of skeletal muscle mass and strength. In the absence of clinically available nutritional solutions specifically targeting MuSCs, we used a human myogenic progenitor (hMP) high-content imaging screen of natural molecules from food to identify nicotinamide (NAM) and pyridoxine (PN) as bioactive nutrients that stimulate MuSCs and have history of safe human use. NAM and PN synergize via CK1-mediated cytoplasmic β-catenin activation and AKT signaling to promote amplification and differentiation of MuSCs. Oral treatment with a combination of NAM/PN accelerates muscle regeneration in vivo by stimulating MuSCs, increases muscle strength during recovery, and overcomes MuSC dysfunction and regenerative failure during aging. Levels of NAM and bioactive PN spontaneously decline during aging in model organisms and inter-independently associate with muscle mass and walking speed in a human cohort of 186 aged people. Collectively, our results establish NAM/PN as a new nutritional intervention that stimulates MuSCs, enhances muscle regeneration, and alleviates age-related muscle decline with a direct opportunity for clinical translation.

Abstract 4115542: Female patients with Andersen-Tawil Syndrome are more prone to develop cardiac arrest.

Background: Andersen-Tawil Syndrome (ATS) is an autosomal dominant disorder characterized by a triad of dysmorphic features, periodic muscular weakness, and ventricular arrhythmias. We presented a meta-analysis of cardiologic-affected ATS patients. Objective: This study sought to compare the characteristic features of ATS according to their gender with a special focus on the cardiologic anomalies. Methods: To enable a meta-analysis, we searched literature reviews of reported cases or cohort studies with ATS between 1994 and 2024. Cases were selected if they presented a cardiologic affection alone or combined with morphologic features, periodic paralysis, or both. A gender comparison was made using the available information. Each variable was calculated using the validated percentage. Numerical variables are expressed as mean or median and SD. Categorical variables are expressed as percentages. Student’s t-test was used for numerical variables. Categorical variables were analyzed using chi-square. The results were expressed as an odds ratio (OR) with a 95% confidence interval (CI). Values of p &lt;0.05 were considered statistically significant. Results: The studied population consisted of 243 cardiologic-affected patients with ATS, 163 females, and 80 Males. Compared to males, females are less likely to present periodic paralysis (p = 0.03, OR = 0.54, 95% CI = 0.30-0.98). Analyzing cardiologic features, females had more syncope episodes than males (73% (n=52) vs. 22.4% (n=15). Only 45% of cases had a prolonged QTc. A longer QTc measure was reported in females (453 ± 52) compared to males (427 ± 55) (p = 0.004). Premature ventricular contractions (PVCs) were the most commonly reported arrhythmia, and bigeminy was the most common type of presentation. Polymorphic PVCs were more prevalent in females than males (p = 0.009, OR = 2.49, 95%CI = 1.24-4.99). Females reported more Ventricular tachycardias (VT) episodes than males, especially Bidirectional (p = 0.01, OR = 2.10, 95%CI = 1.17-3.78). Thirty-five patients had an episode of cardiac arrest, either non-fatal, fatal or in some cases non-fatal, followed by SCD after years. Females were more prone to develop cardiac arrest compared to males (n=29 vs. n=6, respectively; p = 0.03, OR = 2.66, 95%CI = 1.06-6.72). Conclusion: ATS females with cardiologic affection may require a closer follow-up due to the higher risk of developing life-threatening arrhythmias and cardiac arrest than males.

Phase Ib clinical and pharmacodynamic study of the TIE2 kinase inhibitor rebastinib with paclitaxel or eribulin in HER2-negative metastatic breast cancer.

Breast cancer cells disseminate to distant sites via Tumor Microenvironment of Metastasis (TMEM) doorways. The TIE2 inhibitor rebastinib blocks TMEM doorway function in the PyMT mouse model of breast cancer. We aimed to assess the safety and pharmacodynamics of rebastinib plus paclitaxel or eribulin in patients with HER2-negative metastatic breast cancer (MBC). This phase Ib trial enrolled 27 patients with MBC who received 50 mg or 100 mg of rebastinib PO BID in combination with weekly paclitaxel 80 mg/m2 (if ≤ 2 prior non-taxane regimens) or eribulin 1.4 mg/m2 on days 1 & 8 (if ≥ 1 prior regimen). Safety, tolerability and pharmacodynamic parameters indicating TIE2 kinase inhibition and TMEM doorway function were evaluated. No dose-limiting toxicities in cycle 1 or 2 were observed among the first 12 patients at either rebastinib dose level. The most common treatment-emergent adverse events (AEs) were anemia (85%), fatigue (78%), anorexia (67%), leukopenia (67%), increased alanine aminotransferase (59%), hyperglycemia (56%), nausea (52%), and neutropenia (52%). AEs attributed to rebastinib include muscular weakness and myalgias. Intraocular pressure increased at the 100 mg rebastinib dose level, whereas angiopoietin-2 levels increased at both dose levels, providing pharmacodynamic evidence for TIE2 blockade. Circulating tumor cells decreased significantly with the combined treatment. Objective response occurred in 5/23 (22%) evaluable patients. In patients with MBC, the recommended phase 2 dose of rebastinib associated with pharmacodynamic evidence of TIE2 inhibition is either 50 or 100 mg PO BID in combination with paclitaxel or eribulin.

‘No ability to choose freedom’: a qualitative study on people who use drugs’ experiences of compulsory isolation treatment

Background Extensive criminological literature has paid attention to the exacerbation of disadvantage due to compulsory treatment of drug use within vulnerable communities. However, understanding how compulsivity shapes users’ narrative framework and meaning construction of lives is still limited. Methods Based on an ethnography conducted at a Compulsory Isolation Treatment Center (CITC) in Central China, we collect in-depth interview data about how trainees who were convicted as drug dependents experienced and interpreted compulsory treatment in the context of life history. Our coding and case analysis of data illustrate four representative narratives on rehabilitation and reveal different ways of meaning-giving between each other. Results Our finding shows that the experience of incarcerated detoxification did not relieve the social disadvantages of people who use drugs. Instead, it was perceived as a negative encounter that intensified discrimination, deeply ingrained in social identity and constantly resurfaced in everyday life. Specifically, harmful experiences are generated by the punitive management of CITC, which underlines obedience between instructors (police officers) and trainees and encourages mutual distrust among peers. The crippling of interpersonal relationships prevents participants from developing social connections or restoring social skills. We also find trainees’ diverse coping strategies to the punitive institutions, ranging from showing physical weakness for board shelter catering to the standard of conduct for an early release to deciphering the intricacies of power relations in CITC. However, these temporary strategies cannot balance their permanent estrangement from public life and thus make them descend into the invisible confines of societal imprisonment. Implications Our ethnographic descriptions reveal the deliberated production of punishment and isolation in the process of compulsory isolation treatment and explicate the potential proximity between political correctives and drug treatment. We, thus, promote abolishing the compulsory isolation model in China, which stems not only from the inefficiency of the treatment at the medical level but also from the political motivations behind the institution and the superficiality of its moral reshaping.

Effectiveness of Ayush Rasayana A and B on the Quality of Life of Older Adults: Protocol for a Cluster Randomized Controlled Trial.

With advancing age among older adults, the associated debilities increase, indicating a deteriorating health status as there is a gradual loss of muscle mass, strength, and functionality. Ayush Rasayana A and B are coded Ayurvedic medicines developed from herbal extracts. This study has been planned to prevent debilitating conditions and improve the quality of life (QOL) in older adults. This study aimed to assess the effectiveness of Ayush Rasayana A and B on the QOL, quality of sleep, and functionality of older adults, along with the tolerability of the intervention. This was a multicenter, open-label, cluster randomized controlled trial conducted with 720 participants aged 60 to 75 years. The participants were divided into 2 groups (intervention and control), with both receiving Ayurvedic ancillary treatment for 3 months. The intervention group additionally received 10 g of Ayush Rasayana A orally once daily at bedtime for 6 days, followed by 1.5 g of Ayush Rasayana B orally twice daily before food for the remaining 84 days. The assessment criteria included the Older People's Quality of Life Questionnaire Brief, Katz Index of Independence in Activities of Daily Living, Pittsburgh Sleep Quality Index, Five Times Sit-to-Stand Test, and shoulder and scapular movements. Any change in hematological and biochemical parameters and occurrence of treatment-emergent adverse events were also assessed during the study period. The recruitment of the participants started in December 2023, and the final follow-up was completed in April 2024. Out of the total 720 enrolled participants, 686 (95.3%) completed the study up to the last follow-up. This study may provide evidence-based data to establish preventive treatment protocols for enhancing the QOL and functionality among older adults. The study results may also be helpful for the planning of interdisciplinary health policies for improving the health conditions of different populations. DERR1-10.2196/58186.

Transforming Tree Bark Waste into a Green Composite: Mechanical Properties and Biodegradability

In this study, a “green composite” material made from 60% tree bark and 40% polylactic acid (PLA) was fabricated and evaluated according to its mechanical properties and biodegradability. Biodegradation tests were performed in compost, simulated aquatic environments, and natural soil. In compost, the composite degraded steadily and reached 47% biodegradation after 11 weeks. In soil, the material quickly lost much of its tensile strength, and after 6 weeks, there were signs that the surface and the internal structure had started to deform. Biodegradation in aquatic environments also caused a loss of tensile strength after only a few weeks. Because of the high filler content, excellent biodegradability, and light weight, the composite material has a low environmental footprint. The material could be used in agricultural equipment such as plant pots.

Transition from afterglow to streamer discharge in an atmospheric capacitively coupled micro-plasma jet

This Letter focuses on the discharge mechanisms of an atmospheric pressure micro-plasma jet optimized for endoscopic applications in biology and medicine. This capacitively coupled plasma (CCP) features a concentric double flow allowing for shielding the Helium or Neon plasma gas with carbon dioxide from the humid ambient air. High-resolution optical emission spectroscopy allows for the analyses of the Stark effect of the He I 492.19 nm and the Hydrogen Hβ lines to determine the electric field (EF) and the electron density spatially resolved along the discharge expansion outside the source. EF in Neon at atmospheric pressure was reliably determined with the Stark shift measurement of the weak Ne I line at 515.196 nm. In both gases, the EF diagnostic revealed a steep transition from CCP afterglow to streamer discharge with a magnitude up to 30 kV/cm. This research is a significant step forward in the field of plasma medicine with a plasma source capable of delivering a reactive chemistry with or without an intense EF to the target.

An extended kinematic hardening constitutive model to include unsaturated behaviour for the prediction of soil deterioration

Linear geotechnical infrastructure undergoes seasonal volumetric changes due to climatic and hydrological cycles, leading to progressive failure of the soil mass and performance deterioration. The magnitude of the seasonal cycles of pore water pressure is expected to be increased by more extreme and frequent wet and dry events, leading to an accelerated deterioration process. Advanced constitutive models for unsaturated soils able to reproduce the observed behaviour are therefore required. A new advanced constitutive model for the hydro-mechanical behaviour of unsaturated soils is formulated and implemented within the framework of elasto-plasticity with internal variables. The effect of recent suction history is incorporated using a kinematic hardening constitutive model augmented by elements of bounding surface plasticity, initially developed for saturated soils, which is further extended to the unsaturated range through the inclusion of a loading collapse curve. The model permits the retention of information on recent stress history, allows prediction of irrecoverable stiffness and strength loss, and replicates the hysteretic response during cyclic loading. The model has been implemented in a constitutive driver using an implicit numerical scheme and its predictive capabilities are demonstrated by performing numerical simulations of a series of laboratory experiments involving complex sequences of isotropic loading, wetting, drying and shearing stages.

Mechanical properties of MoW–HfN surrogate cermet fuel for nuclear thermal propulsion

AbstractThe mechanical performance of MoW‐HfN, a surrogate cermet for MoW‐UN Nuclear Thermal Propulsion (NTP) fuel, was characterized from room temperature to 1600°C. The modulus of elasticity and flexure strength were obtained from four‐point bend tests. Those tests revealed a loss of stiffness with increasing temperature and systematic increase in ultimate strength up to about 1400°C. This was followed by loss of ultimate strength and the onset of plastic deformation, attributed to the increased ductility of the MoW matrix above 1400°C. Chevron notch tests show that failure originates from features with a critical flaw size of ∼30 εm, which is comparable to the mean particle size of the ceramic phase. X‐ray diffraction (XRD) and Williamson–Hall (WH) analysis suggest that residual stress may contribute to the observed strength‐versus‐temperature behavior.

Hardening properties, water resistance and associated micro-mechanism of nano-modified calcium sulphoaluminate cement

Calcium sulphoaluminate cement (CSA) is considered a sustainable alternative to traditional Portland cement to reduce CO2 emissions. To further improve the hardening properties and water resistance of CSA and advance its extensive special engineering application, nanoparticles including nano-SiO2 (NS), nano-MgO (NM) and nano-Al2O3 (NA) were used as nano-modifiers for CSA. The effects of nanoparticles dosage on the setting time, compressive strength and water resistance of nano-modified CSA were experimentally evaluated, and the micro-mechanisms were also clarified by conducting X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TG) tests. The results showed that incorporating nanoparticles into CSA obviously shortened the initial and final setting times. The appropriate addition of nanoparticles effectively enhanced the compressive strength of CSA, and the optimum dosages of NS, NM, and NA were respectively determined to be 0.5 %, 1.0 %, and 0.5 %. Water immersion decreased the bonding strength of CSA, and adding nanoparticles can effectively weaken this water-induced deterioration effect. Under water immersion environment, the optimum dosages of nanoparticles would be increased to obtain the highest residual water immersion strength and minimum strength loss rate. The generation of ettringite was mainly responsible for the compressive strength and water resistance improvements of nano-modified CSA. The hydration process of nano-modified CSA was clarified and the corresponding micro-mechanism model was proposed. Furthermore, the benefits and challenges of using nano-modified CSA were also analyzed, advancing its widespread application in rapid repair of special engineering.

How People Living With Amyotrophic Lateral Sclerosis Use Personalized Automatic Speech Recognition Technology to Support Communication.

Amyotrophic lateral sclerosis (ALS) is a progressive, ultimately fatal disease causing progressive muscular weakness. Most people living with ALS (plwALS) experience dysarthria, eventually becoming unable to communicate using natural speech. Many wish to use speech for as long as possible. Personalized automated speech recognition (ASR) model technology, such as Google's Project Relate, is argued to better recognize speech with dysarthria, supporting maintenance of understanding through real-time captioning. The objectives of this study are how plwALS and communication partners use Relate in everyday conversation over a period of up to 12 months and how it may change with any decline in speech over time. This study videoed interactions between three plwALS and communication partners. We assessed ASR caption accuracy and how well they preserved meaning. Conversation analysis was used to identify participants' own organizational practices in the accomplishment of interaction. Thematic analysis was used to understand better the participants' experiences of using ASR captions. All plwALS reported lower-than-expected ASR accuracy when used in conversation and felt ASR captioning was only useful in certain contexts. All participants liked the concept of live captioning and were hopeful that future improvements to ASR accuracy may support their communication in everyday life. Training is needed on best practices for customization and practical use of ASR technology and for the limitations of ASR in conversational settings. Support is needed for those less confident with technology and to reduce misplaced allocation of ownership of captioning errors, risking negative effects on psychological well-being.