Performance Test Research Articles

Seismic noise effect suppression for the performance testing of high-precision space electrostatic accelerometers using a torsion pendulum with differential configuration

Seismic noise effect suppression for the performance testing of high-precision space electrostatic accelerometers using a torsion pendulum with differential configuration

Interfacial linkage modulated amorphous molybdenum sulfide/bismuth halide perovskite heterojunction for enhanced visible-light-driven photocatalytic hydrogen evolution

Photocatalytic hydrogen evolution is a promising approach for direct solar-to-fuel conversion. Although significant research efforts have been put on the development of lead-free metal halide perovskites to reach excellent optoelectronic properties, their rational design for efficient heterojunction photocatalytic systems still poses challenges. Here, we report a new strategy to tailor the interface of hybrid tri(dimethylammonium) hexaiodobismuthate (DMA3BiI6) and amorphous molybdenum sulfide (a-MoSx) heterojunctions. Specifically, a-MoSx was prepared with abundant apical S2– or bridging S22– ligands to allow coupling with DMA3BiI6 via an interfacial Mo–S–Bi linkage. The as-obtained heterostructures were found to show an improved visible-light-driven photocatalytic hydrogen evolution in hydroiodic acid splitting under mild conditions reaching a superior hydrogen evolution rate of around 750 µmol g−1 h−1 and an apparent quantum efficiency (AQE) of 13.0 % at 420 nm. The high activity was kept after a long-term performance test for 3 days.

THE IMPACT OF PHET-ASSISTED EXPERIMENTAL LEARNING METHODS ON STUDENTS' SCIENCE PROCESS SKILLS IN SCIENCE TOPICS

The focus of this study is to find out how the PhET-assisted experiential learning technique affects students' Science Process Skills on energy-related material. A quantitative technique was applied in the research design, which was one group pretest posttest. This study will take place in SMP N 1 Sugio Lamongan. Purposive sampling was used in the sample selection process. There were 181 students in this study. The research included 66 students divided into two groups, class A and class B. However, data could not be gathered for 5 kids due to school activities, limiting the sample to 61 students. The insight gathering approach involves cognitive tests and observation of performance tests, followed by hypothesis evaluation with a paired simple t-test. The findings of this investigation show that learning using the PhET-assisted experimental approach to learning encounters a substantial impact on students' Science Process Skills in energy change material, with an average cognitive pretest score of 40.03, a posttest result of 78.95, and an N-gain value of 0.64, and obtained data from performance test observations with a pretest value of 35.65, a posttest result of 84.42, and an N-gain value of 0.75. The integration of experiential learning techniques aided by PhET has an impact on students' Science Process Skills, as evidenced by pretest posttest outcomes that have increased to the moderate level.

Multi-Physics Simulation and Optimization of Jet Electrodeposition for Ni–Diamond Composite Coatings

This work investigated the influence of current density, plating solution flow rate, and nozzle outlet-to-cathode distance on the properties of Ni–diamond composite coatings. A multi-physics field simulation was employed to analyze the interplay between current density, plating solution flow rate, and nozzle outlet-to-cathode distance on the flow field and electric field distribution. Additionally, particle tracing simulations were incorporated into the model to evaluate the incorporation efficiency of diamond particles during composite electrodeposition. It was found that when the inlet flow rate of the electrolyte was 5 L/min, the distance between the nozzle outlet and the cathode was 3 mm, and the current density was 60 A/dm2, the composite electrodeposited coating had a higher particle content and better uniformity. The simulation results were validated through experimental preparation and performance testing. This combined approach provides valuable insights for optimizing the jet electrodeposition process for Ni–diamond composite coatings with superior properties.

Development and validation of a 40 K liquid SNP array for the mud crab (Scylla paramamosain)

Genomic selection (GS) and genome-wide association studies (GWAS) have been widely implemented to accelerate the genetic improvement of important economic traits. Developing an efficient and reliable high-throughput genotyping tool is the premise and basis of implementing GS and GWAS on the mud crab (Scylla paramamosain). In this study, leveraging the whole-genome resequencing data of 146 mud crabs from the southeast coast of China, a total of 16,714,943 high-quality SNPs were discovered. Based on polymorphic information content and evenly distribution on 49 chromosomes, a total of 40,352 SNPs was selected to develop a 40 K liquid SNP array (named “Xiexin No. 1”) using the genotyping by target sequencing (GBTS) technology. The genotyping performance test showed that this SNP array had a high site polymorphism (over 92.70%) and individual calling rate (97.02%). Furthermore, the mean of SNP concordance, genotype concordance, non-reference sensitivity, and non-reference discrepancy between “Xiexin No. 1” SNP array and resequencing were identified to be 0.986, 0.954, 0.942, and 0.097, respectively. Using this SNP array data, the genomic heritabilities were evaluated as 0.887 ± 0.065, 0.643 ± 0.108, 0.599 ± 0.111, and 0.624 ± 0.111 for body weight (BW), carapace length (CL), carapace length (CW), and body height (BH) in a cultured population (233 crabs). Furthermore, six significant SNPs associated with growth traits were identified by GWAS. After annotation, one candidate gene (XP_027221997.1) associated with BW and two candidate genes (XP_027206468.1 and XP_027210446.1) associated with CW and BH were identified. Most importantly, the prediction accuracy of GBLUP for BW, BH, CL, and CW were 0.535 ± 0.064, 0.544 ± 0.101, 0.574 ± 0.087, and 0.585 ± 0.083, with the unbiasedness values of 0.988 ± 0.22, 1.015 ± 0.274, 1.011 ± 0.196 and 1.037 ± 0.235. In conclusion, the “Xiexin No. 1” SNP array provides an efficient and reliable platform for high-quality genotyping, which would greatly promote the genetic studies and thus accelerate the genetic improvement of mud crabs.

Timing Performance Testing and Regularity Analysis of eLoran System

Accurate time synchronisation is critical in modern communication, navigation, and scientific research. In this context, the eLoran receiver, which is an advanced timing device, has attracted increasing scholarly attention. This study aims to comprehensively analyse the performance and potential applications of eLoran systems for timing monitoring and to specifically explore the relevant indices of two eLoran receivers. To this end, we evaluated the performance of these receivers in receiving time signals through both simulated and empirical data and conducted a regularity analysis to uncover their potential value in practical applications. The findings demonstrate that the eLoran receiver excels at timing monitoring and provides highly accurate time information. An analysis of the timing performance of the eLoran system improved its accuracy and integrity.

Patterns of neural activity in prelimbic cortex neurons correlate with attentional behavior in the rodent continuous performance test.

Sustained attention, the ability to focus on a stimulus or task over extended periods, is crucial for higher level cognition, and is impaired in individuals diagnosed with neuropsychiatric and neurodevelopmental disorders, including attention-deficit/hyperactivity disorder, schizophrenia, and depression. Translational tasks like the rodent continuous performance test (rCPT) can be used to study the cellular mechanisms underlying sustained attention. Accumulating evidence points to a role for the prelimbic cortex (PrL) in sustained attention, as electrophysiological single unit and local field (LFPs) recordings reflect changes in neural activity in the PrL in mice performing sustained attention tasks. While the evidence correlating PrL electrical activity with sustained attention is compelling, limitations inherent to electrophysiological recording techniques, including low sampling in single unit recordings and source ambivalence for LFPs, impede the ability to fully resolve the cellular mechanisms in the PrL that contribute to sustained attention. In vivo endoscopic calcium imaging using genetically encoded calcium sensors in behaving animals can address these questions by simultaneously recording up to hundreds of neurons at single cell resolution. Here, we used in vivo endoscopic calcium imaging to record patterns of neuronal activity in PrL neurons using the genetically encoded calcium sensor GCaMP6f in mice performing the rCPT at three timepoints requiring differing levels of cognitive demand and task proficiency. A higher proportion of PrL neurons were recruited during correct responses in sessions requiring high cognitive demand and task proficiency, and mice intercalated non-responsive-disengaged periods with responsive-engaged periods that resemble attention lapses. During disengaged periods, the correlation of calcium activity between PrL neurons was higher compared to engaged periods, suggesting a neuronal network state change during attention lapses in the PrL. Overall, these findings illustrate that cognitive demand, task proficiency, and task engagement differentially recruit activity in a subset of PrL neurons during sustained attention.

Preparation and performance analysis of nano‐crosslinking agent for sulphonated guar gum fracturing fluid

AbstractIn order to solve the problems of poor temperature resistance and low crosslinking efficiency of crosslinking agent for sulphonated guar gum fracturing fluid, in this paper, nano‐silica was reacted with 3‐aminopropyltriethoxysilane to obtain surface‐modified nano‐silica, which was then reacted with boric acid and n‐butyl titanate to obtain nano‐silica‐based boron‐titanium composite crosslinking agent. Its physical properties and structure were characterized by infrared (IR), laser particle size analysis, X‐ray diffraction (XRD), and atomic force microscopy (AFM). The sulphonated hydroxypropyl guar gum fracturing fluids formed by nano‐crosslinking agent were analyzed: When the temperature was uniformly increased from 25 to 120°C and the shear rate was 170 s−1, the viscosity was finally constant at about 50 mPa · s, which indicated that the temperature and shear resistance were good; the system had a better filtration‐loss reduction performance; the average sedimentation rate of ceramic grains in the fracturing fluid system was 0.00872 cm · min−1, indicating that the system had good sand carrying performance; the damage rate of fracturing fluid filtrate to the core was 23.33%; the gel breaking performance test showed that the fracturing fluid had good gel breaking performance. By analyzing the performance of the fracturing fluid, it can be seen that the nano‐crosslinking agent has the advantages of good temperature resistance and high cross‐linking efficiency compared with the traditional boron and titanium cross‐linking agents.

Thinking about numbers in different tongues: An overview of the influences of multilingualism on numerical and mathematical competencies.

In an increasingly multilingual and multicultural world, understanding the interactions between language and mathematics is critical, especially when individuals must acquire and exercise their mathematical competencies in multiple languages. Indeed, research shows that, overall, L2 language learners are at an academic disadvantage compared to their L1 peers. The current article briefly overviews how multilingualism influences basic and advanced mathematical skills and interacts with mathematical learning difficulties. We first outline the traditional cognitive models of number learning and language processing. We then discuss the particularities of multilingualism and how it impacts numerical skills such as counting and building lexical-semantic associations, transcoding and arithmetic, mathematical word problems and mathematical performance tests, and dyscalculia diagnosis. We end this review by outlining challenges, recommendations, and solutions for multilingual educational settings. The article is intended as a guide for numerical cognition researchers who work with diverse populations and for mathematics educators and educational policy-makers facing the challenges of a multilingual classroom.

Integrative Learning Model in Pediatric and Sorches on Athletics Materials with Science Education Biology Materials for Junior High School Students

This research aims to produce an integrative learning model for junior high school students that is suitable for use. The integrative learning model is expected to be used by physical education teachers in teaching and learning activities. This development research was carried out by adapting the following research steps: data collection, analysis of the information collected, development of initial product draft, expert validation and revision, small-scale trials and revisions, large-scale field trials and revisions, and final product creation. A small-scale trial was carried out on 25 students of SMP Negeri 1 Samarinda. Large-scale trials were carried out on 31 students of SMP Negeri 2 Samarinda, SMP Negeri 3 Samarinda, and SMP Negeri 4 Samarinda. Data collection instruments are interview guides, field notes, validation value scales, teacher participation, student responses, performance tests and knowledge tests. Data analysis uses qualitative and quantitative descriptive analysis. The results of this research are in the form of a guidebook containing syntax (steps), assessment forms, 6 integrative games, and plans for implementing appropriate and effective learning.

Impact of frailty, early vascular decline and subclinical cognitive impairment in midlife adults: study protocol of the Toledo Study for Healthy Ageing in middle age.

Life expectancy has increased worldwide alongside a rise in disability prevalence during old age. The impact and interrelationship among the precursors of disability in midlife remain to be better understood. Furthermore, investigating whether lifestyle factors may potentially influence health outcomes and the prognosis of vascular disease could be especially relevant among the middle-aged population, which is a priority subpopulation when prevention is the goal. This is an observational, cross-sectional and population-based study. Participants, between 50 and 55 years old, are randomly selected from the municipality of Toledo (Spain). There are six non-consecutive days for the assessments, providing enough rest between evaluations. Participants perform the interview of the Toledo Study for Healthy Aging. Blood pressure monitoring and a resting electrocardiogram are also recorded. Then, resting peripheral and cerebral vascular measurements along with muscle size and architecture are assessed. Blood and urine samples, and body composition data are collected after an overnight fasting. On a different visit, physical performance and muscle function tests are performed. Additionally, brain magnetic resonance imaging is conducted. And finally, an accelerometer is given to the participants for a week. Frailty is evaluated by Frailty Trait Scale and Fried Frailty Phenotype. This project will shed light on the associations between frailty, early cognitive impairment, and vascular aging during midlife, and on the role that lifestyles play in their development. Lastly, this project will provide meaningful implications for public health strategies aimed at promoting healthy aging in later life.

Performance evaluation of the 3D-ring cadmium–zinc–telluride (CZT) StarGuide system according to the NEMA NU 1-2018 standard

BackgroundThe application of semi-conductor detectors such as cadmium–zinc–telluride (CZT) in nuclear medicine improves extrinsic energy resolution and count sensitivity due to the direct conversion of gamma photons into electric signals. A 3D-ring pixelated CZT system named StarGuide was recently developed and implemented by GE HealthCare for SPECT acquisition. The system consists of 12 detector columns with seven modules of 16 × 16 CZT pixelated crystals, each with an integrated parallel-hole tungsten collimator. The axial coverage is 27.5 cm. The detector thickness is 7.25 mm, which allows acquisitions in the energy range [40–279] keV. Since there is currently no performance characterization specific to 3D-ring CZT SPECT systems, the National Electrical Manufacturers Association (NEMA) NU 1-2018 clinical standard can be tailored to these cameras. The aim of this study was to evaluate the performance of the SPECT/CT StarGuide system according to the NEMA NU 1-2018 clinical standard specifically adapted to characterize the new 3D-ring CZT.ResultsDue to the integrated collimator, the system geometry and the pixelated nature of the detector, some NEMA tests have been adapted to the features of the system. The extrinsic measured energy resolution was about 5–6% for the tested isotopes (99mTc, 123I and 57Co); the maximum count rate was 760 kcps and the observed count rate at 20% loss was 917 kcps. The system spatial resolution in air extrapolated at 10 cm with 99mTc was 7.2 mm, while the SPECT spatial resolutions with scatter were 4.2, 3.7 and 3.6 mm in a central, radial and tangential direction respectively. Single head sensitivity value for 99mTc was 97 cps/MBq; with 12 detector columns, the system volumetric sensitivity reached 520 kcps MBq−1 cc−1.ConclusionsThe performance tests of the StarGuide can be performed according to the NEMA NU 1-2018 standard with some adaptations. The system has shown promising results, particularly in terms of energy resolution, spatial resolution and volumetric sensitivity, potentially leading to higher quality clinical images.

SPIKES: Skills and Performance Inventory as Kinesiological Assessment for Empowerment of Sepaktakraw Athletes

This research presents a comprehensive assessment of Sepaktakraw athletes at Batangas State University (BatStateU) TNEU, aiming to enhance athlete development through evidence-based methodologies. Recognizing the global trend towards universities' pivotal role in athlete development, the study addresses the diverse landscape of sports programs, particularly focusing on Sepaktakraw in the Philippines. BatStateU's visionary 5-year development plan emphasizes creating champion athletes, aligning with global trends and emphasizing sports infrastructure and training programs. However, the study identifies an opportunity to enhance training programs by introducing the SPIKES program, incorporating kinesiological assessments for a more scientific and tailored approach. Using a descriptive survey methodology, the research integrates Physical Fitness and Skill-specific Performance Tests to evaluate Sepaktakraw athletes comprehensively. Anthropometric profiling revealed diverse body compositions, while physical fitness assessments highlighted variations in speed, agility, strength, and more. Skill-specific performance evaluations in serving, spiking, and game-specific skills provided insights into athletes' proficiency levels. Results categorized athletes into four kinesiological profiles (A, B, C, D), guiding the design of personalized training programs. The Skill-Specific Training Program, unfolding over 12 weeks, targets specific improvements in physical fitness and skills. This evidence-based approach offers a systematic framework for optimizing Sepaktakraw athletes' performance, providing valuable insights for coaches, trainers, and athletes alike. The study not only enhances BatStateU's athlete development initiatives but also serves as a model for personalized and scientifically rigorous training programs in Sepaktakraw and potentially other sports.

Unleashing the Potential of β -cyclodextrin Inclusion Complexes in Bitter Taste Abatement: Development, Optimization and Evaluation of Taste Masked Anti-emetic Chewing Gum of Promethazine Hydrochloride.

Motion sickness also known as kinetosis is a condition in which there exists a disagreement between visually perceived movement and the vestibular system's sense of movement. Nausea, vomiting, dizziness, fatigue, and headache are the most common symptoms of motion sickness. This study mainly focuses on the taste masking of Promethazine Hydrochloride (PMZ) by inclusion complexation method, its formulation development in the chewing gum form by using directly compressible gum base HIG® and its quality and performance testing. Different molar ratios (1:1, 1:2, 1:3 and 1:4) of PMZ-cyclodextrin complexes were prepared by using β-Cyclodextrin(β-CD) as a taste masking agent. These complexes were evaluated for FTIR, DSC, % Entrapment Efficiency, % drug yield, and taste evaluation by E-Tongue. The optimized ratio was further evaluated by sophisticated analytical techniques such as Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD). A central composite design (CCD) (3 ^2) was utilized to examine the effects of independent variables (amount of gum-X1 and amount of plasticizer-X2) on dependent variables (%CDRY1 and hardness Y2). The prepared gums were evaluated for drug content, organoleptic properties, in-vitro dissolution testing by fabricated disintegration apparatus, texture analysis, etc. The optimization statistics showed that on decreasing the amount of gum, in- vitro drug release increases and hardness decreases. The optimized batch MCG-2 of Promethazine MCG showed 92.34 ± 0.92% of drug release, whereas for marketed formulation (Phenergan®-25mg) drug release value was 86.19 ± 1.88%. Results provided evidence that PMZ MCGs could be a better alternative to conventional tablet formulations with improved drug release, palatability and texture.

Grey matter ageing-related tau astrogliopathy: associations with brain pathologies and cognitive decline.

Grey matter ARTAG pathology is common in aged brains and detected in multiple brain regions. However, the associations of grey matter ARTAG with Alzheimer's disease (AD) and other common age-related proteinopathies, as well as clinical phenotypes including Alzheimer's dementia and cognitive decline remain unclear. We examined 442 decedents (mean age-at-death=90 years, males=32%) from three longitudinal community-based clinical-pathological studies. Using AT8 immunohistochemistry, grey matter ARTAG pathology was counted in the the superior frontal, anterior temporal tip, and amygdala and summarized as a severity score from 0 (none) to 6 (severe). AD and other common age-related neuropathologies were also evaluated. The diagnosis of Alzheimer's dementia was based on clinical evaluations; annual tests of cognitive performance were summarized as global cognition and five cognitive domains. Multivariable logistic regression tested the associations of grey matter ARTAG pathology with an array of age-related neuropathologies. To evaluate associations of grey matter ARTAG pathology with Alzheimer's dementia and cognitive decline, we employed logistic regression and linear mixed effect models. Grey matter ARTAG pathology was seen in 324 (73%) participants, of which 303 (68%) participants had ARTAG in the amygdala, 246 (56%) in the anterior temporal tip, and 137 (31%) in the superior frontal region. Grey matter ARTAG pathology from each of the three regions was associated with pathologic diagnosis of AD and LATE-NC but not with vascular pathology. In fully adjusted models that controlled for demographics, AD, and common age-related pathologies, an increase in severity of grey matter ARTAG pathology in the superior frontal cortex, but not in the amygdala or the anterior temporal tip, was associated with higher odds of Alzheimer's dementia and faster decline in global cognition, episodic memory, and semantic memory. These results provide compelling evidence that grey matter ARTAG, specifically in the superior frontal cortex contributes to Alzheimer's dementia and cognitive decline in old age.

Predicting performance in attention by measuring key metabolites in the PCC with 7T MRS

The posterior cingulate cortex (PCC) is a key hub of the default mode network and is known to play an important role in attention. Using ultra-high field 7 Tesla magnetic resonance spectroscopy (MRS) to quantify neurometabolite concentrations, this exploratory study investigated the effect of the concentrations of myo-inositol (Myo-Ins), glutamate (Glu), glutamine (Gln), aspartate or aspartic acid (Asp) and gamma-amino-butyric acid (GABA) in the PCC on attention in forty-six healthy participants. Each participant underwent an MRS scan and cognitive testing, consisting of a trail-making test (TMT A/B) and a test of attentional performance. After a multiple regression analysis and bootstrapping for correction, the findings show that Myo-Ins and Asp significantly influence (p < 0.05) attentional tasks. On one hand, Myo-Ins shows it can improve the completion times of both TMT A and TMT B. On the other hand, an increase in aspartate leads to more mistakes in Go/No-go tasks and shows a trend towards enhancing reaction time in Go/No-go tasks and stability of alertness without signal. No significant (p > 0.05) influence of Glu, Gln and GABA was observed.

Development and thermal performance testing of radiant conditioning ceiling panels

The past decades have seen an advancement from heavyweight radiant floors to lightweight conditioning ceiling systems. However, the performance of these lightweight systems are seldom comprehensively discussed in an informative manner for designers. This paper reviews lightweight radiant ceiling panel designs and conducts instrumental experiments to examine the thermal performance of different designs. Four distinct capillary hydronic panels have been designed and developed to assesses their thermal performance via empirical testing and measurement. Prototypes were built and integrated into a suspended ceiling system where they were tested in cooling mode. The response time, surface temperature, and energy transfer of the different panel designs were investigated. The experiment results show that higher thermal mass yields higher heat transfer and better surface temperature, but longer response time. A better thermal connection between the capillary tubes and the radiant surface also results in better conduction, faster response times, and improved surface temperature.

Research on flexural mechanical properties and mechanism of green ecological coir fiber foamed concrete (CFFC)

To explore the effect and mechanism of coir fiber on the performance of foamed concrete, the flexural performance test, pore characteristics and microstructure test of coir fiber foamed concrete with different content were carried out. First, Image-Pro Plus (image processing software) was used to study the pore morphology, porosity, average pore diameter, and pore roundness of CFFC with various fibers dosage (0, 0.5%, 1.0%, 1.5%, 2.0%, 2.5%) by binarization processing method. Then, a total of eighteen specimens, divided into six groups, were used to investigate the effect of CF dosage on flexural strength, toughness, energy absorption, and failure patterns of FC through a three-point flexural test. Furthermore, the microscopic properties of coir fiber foamed concrete (CFFC) were observed by scanning electron microscope (SEM) and energy dispersive X-ray detector (XRD) to explain the influence mechanism of CF on FC flexural properties. According to the research, CF can affect the pore characteristics of CFFC and improve its flexural performance. When CF content is 1.5–2.0%, the porosity, diameter and roundness of CFFC have lower values of 68.6%, 1.96 mm and 1.29. After the fiber dosage reaches 1.5%, the CFFC failure mode changed to plastic damage, the flexural strength increased from 0.33 to 0.73 MPa, and the toughness energy absorption value was increased from 0.05 to 1.4 J. The optimum dosage of coir fiber is 2.0% for improving the flexural mechanical properties of FC. CF affects the process of hydration reaction of CFFC, but does not change the type of hydration product. However, the flexural performance of FC would decrease with excessive dosage of CF (> 2.0%) due to accelerating the formation of Ca(OH)2. CFFC can solve problems such as brittleness and easy cracking existing in traditional foamed concrete, and it can be used in the field of pavement engineering, foundation backfill and lightweight wall structure with CF dosage of 15–2.0%.

Innovative strategy for the facile construction of active multifunctional coating on inert thermal insulation surface

Ethylene propylene diene monomer rubber is highly attractive as a thermal insulation material for solid rocket motors but is plagued by its inherent low wettability. Existing methods have been used to solve this problem by manually or mechanically sanding the surface, which is environmentally hazardous. Herein, a multifunctional composite coating is constructed on the surface of inert thermal insulation materials using a two-step low temperature plasma surface treatment via an efficient hydrogen-bonding assembly strategy. The resultant composite coating exhibits excellent adhesion to the inert thermal insulation substrate. Benefitting from this, the coating retained its superhydrophilicity after 80 abrasion cycles and 12 h of agitation scrubbing with saturated salt water. Due to the superhydrophilicity of the coating, a self-cleaning effect for oils of different viscosities on the surface can be achieved by the simple action of water. Besides the adiabatic performance tests showed that the average top surface temperature of the coated thermal insulation was 30.9 °C lower than that of the original thermal insulation. Char residue analysis showed that the coating formed a more complete char layer at high temperatures, resulting in improved adiabatic performance. Our work would afford a new frontier to fabricate solid rocket motor thermal insulation materials with excellent surface comprehensive properties in a simple, eco-friendly and sustainable way, opening new possibilities for the advancement of high-performance inert materials.

Development of high-strength geopolymer mortar based on fly ash-slag: Correlational analysis of microstructural and mechanical properties and environmental assessment

Given the insufficient mechanical performance of existing fly ash-based geopolymer mortars under ambient curing conditions, this study is dedicated to developing a high-strength geopolymer mortar that meets the requirements of modern structural engineering. Based on the rheological performance tests of the fresh geopolymer mortar, the evolution of its rheological characteristics was revealed. Through macroscopic mechanical performance tests, the influence of slag content on the compressive and flexural strength of geopolymer mortar was clarified. Employing microstructural performance testing methods such as Thermogravimetric and Mercury Intrusion Porosimetry, the micro-mechanisms behind the improvement of mechanical properties were revealed. Utilizing the grey relational analysis method, a framework was established to analyze the correlation between the microstructural and macroscopic mechanical properties of geopolymer mortar. Additionally, an assessment system for evaluating environmental and economic benefits was developed using statistical analysis methods. The results show that increasing slag content enhances the yield stress and plastic viscosity of geopolymer mortar. Optimizing slag content boosts the compressive strength of fly ash-based geopolymer mortar, reaching up to 88.13 MPa under ambient curing conditions. An optimal amount of slag also promotes gel formation during polymerization, improving the internal pore structure. Furthermore, the content of reaction products correlates more strongly with macroscopic mechanical properties than pore structure characteristics. Geopolymer mortar also presents significant environmental and economic advantages over traditional cement-based materials, with its carbon and economic intensity indices at only 5.50 % and 10.80 %, respectively, of those in cement-based materials.