Test Methodology Research Articles

Development and Optimization of Geopolymer-Based Artificial Angular Coarse Aggregate Using Cut-Blade Mechanism

This research introduces a novel approach to developing geopolymer-based artificial coarse aggregate using a cut-blade mechanism, providing an innovative approach to traditional aggregate. A modified concrete drum mixer equipped with additional cutting blades was employed to produce angular aggregates with consistent particle sizes ranging from 10mm to 20mm with rough surface texture. Compared to conventional techniques, this method ensures a more uniform aggregate shape, enhancing its mechanical interlocking properties in construction applications. The experimental results demonstrated abrasion values between (13.2% to 31.5%), impact value test (9.8% to 21.6%), water absorption rates of (2.62% to 4.2%), and specific gravity values ranging from (1.18 to 2.2). To further optimize the alkali activator dosage, a mathematical model was developed using the ANOVA test and Response surface methodology (RSM), achieving high regression predictive accuracy with R2 values > 0.93. The model demonstrated optimal results between experimental results and predicted results for specific gravity, impact value, abrasion value, and water absorption. Microstructural analysis via Scanning electron microscopy (SEM) reveals optimal pore distribution inside aggregates, while X-ray Fluorescence identifies significant intensities of Quartz, Ettringite, and calcium silicate hydrate gel. Overall, this research not only demonstrates the technical feasibility of producing high-performance artificial aggregate from waste materials but also underscores its potential to mitigate environmental impacts and promote sustainable construction practices.

Methodology of Testing for Aluminium Honeycomb Impact Attenuator in Quasi-Static Conditions and Influence of Supporting Structures

Methodology of Testing for Aluminium Honeycomb Impact Attenuator in Quasi-Static Conditions and Influence of Supporting Structures

Improving Turnaround Times for Routine Antimicrobial Sensitivity Testing Following European Committee on Antimicrobial Susceptibility Testing Methodology in Patients with Bacteraemia

Background/Objectives: Bacteraemia can be fatal without antibiotic intervention. Antibiotic Susceptibility Testing (AST) provides the necessary information for targeted antibiotic therapy; however, the traditional method using disc diffusion can take over two days from a positive blood culture. Inappropriate empiric therapy is associated with increased mortality and increased antibiotic resistance, highlighting the need for more rapid turnaround times for AST. By making changes to an established method, turnaround times can be reduced. Methods: Eighty-two patient positive blood culture samples were collected from January to April 2022, representing the range of common bacteria causing sepsis. This followed the normal methodology in the laboratory of inoculating agar from positive blood cultures in preparation for European Committee on Antimicrobial Susceptibility Testing (EUCAST) disc diffusion AST method. EUCAST methodology outlines that disc diffusion should be performed on isolates from an overnight culture of 16–24 h. This study looked at comparing disc diffusion results from cultures with 6 h of incubation to those with incubation times of 24 h, after organism identification by MALDI-ToF. Results from 6-h and 24-h cultures were compared by disc zone sizes and by interpreted susceptibility reading following EUCAST guidelines of sensitive, resistant, susceptible with increased exposure, or an area of technical uncertainty. Results: A total of 99.65% interpreted susceptibility readings matched across all organisms to all relevant antibiotics, with an average zone size difference of 1.08 mm between results from 6 h versus 24 h cultures. Conclusions: This method offers a non-automated way of using the traditional disc diffusion method, reducing turnaround times while still producing reliable and accurate results. This would mean validated ASTs can be set up in the same day as a blood culture flags positive rather than waiting for a longer culture. As this method is widely used within the laboratory already, it would mean that additional training is not required, as the process is the same, and only incubation time varies. This would positively impact patient outlook due to the shorter use of empiric therapy, and benefit antimicrobial stewardship (AMS).

Development of an experimental unit and methodology for ground-based experimental testing of two-phase thermoregulation systems for spacecrafts

Development of an experimental unit and methodology for ground-based experimental testing of two-phase thermoregulation systems for spacecrafts

Wood–Cement Composites: A Sustainable Approach for Mitigating Environmental Impact in Construction

The construction industry’s environmental impact has become a growing concern, largely due to the energy-intensive production of conventional building materials. This paper explores the potential of wood–cement composites as a more sustainable alternative through a comprehensive literature review, including a bibliometric and scientometric analysis of research trends. Our analysis traces the evolution of wood–cement composites from early studies focused on mechanical properties, to recent investigations into their environmental benefits and practical applications. Key findings suggest that optimal performance can be achieved by treating wood with tetraethyl orthosilicate, incorporating additives like cellulose nanocrystals or wollastonite, and using wood from species such as Pinus. While partial cement replacement with wood waste and ash offers significant environmental advantages, precise formulations are needed to maintain structural integrity. This study also acknowledges certain methodological limitations, such as the reliance on keyword-based filtering, which may have excluded some relevant studies. Future research should address long-term durability, economic feasibility, and standardized testing methodologies to facilitate the adoption of wood–cement composites in the construction industry. These materials, particularly suitable for non-structural applications and insulation, hold promise as viable, eco-friendly building solutions capable of reducing the construction industry’s carbon footprint.

Cognitive and behavioral response of mosquitofish (Gambusia affinis) to environmental factors: Microplastics, predator cues, and detour design methods.

Urban stream syndrome is the collective term used to describe the physical and ecological degradation of streams draining urban lands that poses substantial threats to freshwater ecosystems. Among various consequences of urban expansion, microplastic pollution and shifts in predator-prey dynamics are prominent alterations to natural habitat that could impact the cognitive and behavioral responses of aquatic species. To explore how symptoms of urban stream syndrome impact the cognitive and behavioral responses of fish, we conducted two experiments using a delayed detour test to measure risk-taking and inhibitory control in Gambusia affinis. In the first experiment, we hypothesized that G. affinis exposed to different concentrations of microplastics would show altered inhibitory control and risk-taking. In the second experiment, we hypothesized that exposure to predator chemical cues during the detour task would alter inhibitory control and risk-taking in G. affinis. We did not find significant differences in inhibitory control or risk-taking in G. affinis exposed to microplastics or predator cues. We then compared the effect size and confidence intervals (CI) of these results with published results that used the same detour test to study inhibitory control and risk-taking in G. affinis in response to different environmental conditions. Our investigations revealed that the CIs of the two studies presented here were larger than the CIs in the previously published studies. We consider potential changes to the experimental design that might have affected our ability to detect differences, such as the dimensions of the testing tanks. We also suggest extending the duration of the test to allow ample time for both exiting the starting chamber and solving the detour. We also propose considering the size and age of the species under study and adjusting the dimensions used in the detour paradigm design. Although our findings are specific to G. affinis, our results underscore the importance of considering aspects of the detour test design that are ecologically relevant to the study species when analysing cognitive and behavioral responses in fish. With our discussion, we contribute to the understanding of detour test methodologies and highlight potential ecological factors that could influence cognitive and behavioral outcomes.

Pine Needle of Pinus koraiensis (Siebold & Zucc) Essential Oil Through Liquid Nitrogen Quick-Freezing Assisted Solvent-Free Microwave Extraction Process for Antibacterial Application.

This study investigates the composition and antibacterial properties of essential oil extracted from Pinus koraiensis (Siebold & Zucc) pine needles using a liquid nitrogen freezing treatment combined with solvent-free microwave extraction (LNSFM). The aim is to develop a low-energy, high-efficiency extraction method for conifer essential oils, analyze their chemical composition, and evaluate their antibacterial efficacy. Pine needle samples were frozen with liquid nitrogen and subsequently crushed. The essential oil was extracted using solvent-free microwave technology. A single-factor test and response surface methodology were employed to optimize extraction parameters. The extraction efficiency of LNSFM was compared with traditional methods through kinetics, and the essential oil components were analyzed using gas chromatography-mass spectrometry (GC-MS). The antibacterial activity of the extracted volatile oil was tested against Escherichia coli and Staphylococcus aureus. LNSFM proves to be a green and efficient extraction method suitable for obtaining volatile oils from pine needles, which demonstrate significant antibacterial properties.

Immunofluorescence Use and Techniques in Glomerular Diseases – A Review

Background: Immunofluorescence (IF) studies play an essential role in the evaluation of medical renal biopsies. Particularly, in the study of renal glomerular diseases, where it provides fundamental data for the diagnosis, classification, and etiology of the glomerular pathologies. Diverse techniques may be used to optimize the utilization of IF studies, from variations on the test methodologies to expertise on the interpretation of the results and knowledge of potential pitfalls. Summary: This manuscript presents a brief review on the history of IF and its utilization in kidney pathology, followed by a description of the IF methods, including the use of immunofluorescence on paraffin embedded tissue (paraffin IF), and other novel techniques. Guidelines on how to best report IF findings are reviewed, along with a description of antibodies commonly used in glomerular diseases, highlighting their distribution within the normal kidney and potential pitfalls in interpretation. Finally, the use and interpretation of IF is discussed in more detail in individual entities on a range of glomerular diseases. Key Messages: Immunofluorescence is crucial for interpretation of renal biopsies and diagnosis of glomerular diseases. Knowledge of IF techniques, alternative procedures, its use and proper interpretation is essential for optimal utilization of IF in renal pathology, and this review proposes to serve as a simplified and practical guide on this topic.

Optimizing API Project Efficiency: Agile Configurations, Advanced Design Patterns, and Testing Strategies

In the rapidly evolving digital era, Application Programming Interfaces (APIs) have emerged as the cornerstone of modern software development, enabling seamless communication and data exchange between disparate systems. Optimizing API project efficiency is paramount for organizations aiming to stay competitive and agile in response to market demands. This paper explores strategies for enhancing API efficiency through agile configurations, advanced design patterns, and comprehensive testing methodologies. We delve into the significance of decoupling configurations to achieve agile adaptability, discuss various API design paradigms like RESTful APIs and GraphQL, and examine their specific use cases and benefits. Additionally, we emphasize the importance of robust testing and security practices, highlighting industry-standard tools and technologies that facilitate these processes. Real-world case studies are presented to illustrate practical implementations, and the tangible improvements achieved. By integrating these advanced strategies, organizations can enhance their API performance, scalability, and maintainability, thereby delivering superior value to users and stakeholders in an increasingly interconnected world. Keywords: API efficiency, agile adaptability, decoupling configurations, RESTful API, GraphQL, API testing, microservices, API gateway, performance optimization, configuration management, API security, authentication, automated testing, real-world case studies

Inference of Some Macroeconomic Variables on Nigeria Unemployment Rate

This research investigates the impact of foreign direct investment (FDI), government expenditure (GOE), and inflation rate (IFR) on the unemployment rate (UPR) in Nigeria from 1985 to 2021 through Autoregressive Distributed Lag (ARDL) modeling approach. An initial assessment to test the significance of signals between each independent variable and UPR was performed using rolling correlation analysis. Subsequently, the bounds test methodology to examine cointegration among between the FDI, GOE, IFR, and UPR was performed. Additionally, the causal relationship between these economic variables was performed through the Error Correction Model (ECM) approach. The estimated ARDL model parameters stability was determined using the cumulative sum (CUSUM) of squares chart. The Augmented Dickey Fuller unit root test suggests that the variables are stationary at first differences (I(1)). The bounds test revealed that the variables are cointegrated at 1%, 5%, and 10% indicating a long run relationship between UPR and FDI, GOE, and IFR. The ARDL results indicates that at 5%, a unit increase in FDI at lag one have a long run significant decreasing impact on UPR by 19.96%. But in the short run, the FDI at lag one has a significant increasing effect on UPR by 7.23%. However, the CUSUM of square chart shows unstable parameter estimation based on the Akaike Information Criteria selected model, ARDL (1, 3, 0, 0). The study concludes that UPR is being influenced by FDI in reducing UPR in the long run. Recommendation based on the findings is that FDI should be considered most important when policies are drafted for tackling the issue bordering UPR in Nigeria.

Detection of Cut-Out in Aluminum Plate Using Ultrasonic Guided Waves: A Finite Element Analysis

<div>Aluminum alloys serve a critical role in the aerospace industry, accounting for a significant amount of commercial aircraft weight. Despite the growing use of composite materials, aluminum remains important in airframe construction due to its lightweight, cost-effectiveness, and high strength potential. Structural integrity is critical in modern engineering, necessitating early diagnosis and localization of damage. To detect the flaws, cracks, and cut-out in the structures, structural health monitoring (SHM) systems are essential, with non-destructive testing (NDT) methodologies playing critical roles. Among these technologies, ultrasonic guided wave testing (UGWT) has gained popularity because of its capacity to propagate over long distances and detect subsurface faults. This article investigates the use of UGWs to identify cut-outs in aluminum plates. The numerical investigation has been carried out using commercially available finite element software Abaqus. The ultrasonic lamb waves are generated through the load. The results obtained in pristine and defected 2D aluminum plate has been compared with proper selection of actuation and sensing points. Further by changing the location of actuation and sensing points the shift of damage scattering components has been observed. After identification of reflected wave mode, the location of the cut-out can be predicted accurately.</div>

Modernizing Enterprise Development: Harnessing SAP CAPM and OData for Cloud-Native and Microservices Architectures

This article presents a comprehensive architectural approach for building a highly resilient system capable of processing 5-10 billion events daily. In response to the exponential growth of data generation across industries, we explore the design principles and technologies required to handle massive-scale event ingestion, real-time processing, and complex analytics. The article details the implementation of a solution utilizing managed services, microservices architecture, and cloud-native data warehousing, addressing key challenges such as scalability, low latency, fault tolerance, and cost-efficiency. We discuss the critical role of Infrastructure as Code (IaC) in maintaining consistency and enabling rapid scaling. The article also covers robust testing methodologies and performance validation strategies essential for ensuring system reliability at scale. By sharing real-world performance metrics and lessons learned, this article provides valuable insights for organizations aiming to build next-generation data processing systems that can drive real-time decision-making and maintain competitiveness in the data-driven economy.

Long-term skid resistance evolution and influence mechanism of asphalt pavement based on self-developed wear equipment

Skid resistance decay is the critical functional distress of asphalt pavement, directly restricting its safety and service life. In order to grasp the characteristics and mechanism of long-term skid resistance evolution, this study developed a laboratory wheel-accelerated wear equipment (WAWE) and its testing methodology for asphalt pavement and coarse aggregate. Five coarse aggregates and five gradations combinations were selected to investigate the evolution. The accuracy of the evolution model and the loading conversion relationship were analyzed based on the Research Institute of Highway (RIOH) Track. Finally, the pavement anti-skid texture tester (PATT) was used to investigate the evolution characteristics of coarse aggregate microtexture. Results showed that the Asymptotic evolution model could characterize the skid resistance under the influence of coarse aggregate and gradation. RIOH Track verified the model's accuracy and showed that a single WAWE wear was equivalent to 265 loading times on actual pavement. The long-term skid resistance could be improved by increasing the nominal maximum particle size and the gradation fractal dimension indexes D and Df. The microtexture roughness of the coarse aggregate decreased after wear, then stabilized and fluctuated, which showed "regeneration" characteristics. The study can guide asphalt mixture design and maintenance timing decisions based on long-term skid resistance.

Circular Economy for Transport Infrastructure: An Overview of the Sustainable Use of Recycled Asphalt Shingles in Asphalt Mixtures

In North America and Europe, asphalt shingle waste created during the installation of roofing membranes and tear-off shingles retrieved at the end of the membrane’s life cycle are two major sources of municipal solid waste. Since almost 15–35% of recycled asphalt shingles (RAS) consist of an asphalt binder, the effective recycling of RAS into asphalt mixtures could also allow a reduction in the consumption of non-renewable resources such as asphalt binders. In this context, several studies investigating the use of RAS in asphalt mixtures can be found in the literature, although they exhibit widespread and sometimes conflicting information about the investigated materials, the mix preparation and testing methodologies and the experimental findings. Given this background, this review paper aims at summarizing the existing information and research gaps, providing a synthetic and rational picture of the current literature, where similar attempts cannot be found. In particular, different research studies show that the use of RAS in asphalt mixtures is an economical as well as an eco-friendly option. RAS with up to 20% by weight of binder or 5% by weight of aggregate/mixtures (eventually in combination with 15% reclaimed asphalt pavement aggregate) were found to be relatively suitable to improve the performance properties of asphalt mixtures, both in the laboratory and in the field. Adding RAS to asphalt mixtures could enhance their stiffness, strength and rutting resistance (i.e., high-temperature properties), while negatively affecting the mixtures’ fatigue and thermal cracking resistance. However, the addition of specific biomaterials (e.g., bio-binders, bio-oils) or additives to asphalt mixtures can mitigate such issues, resulting in lower brittleness and shear susceptibilities and thus improving the anti-cracking performance. On the other hand, the literature review revealed that several aspects still need to be studied in detail. As an example, RAS-modified porous asphalt mixtures (fatigue, rutting, moisture susceptibility and thermal cracking) need specific research, and there are no comprehensive research studies on the effects of the RAS mixing time, size and mixing temperature in asphalt mixtures. Moreover, the addition of waste cooking/engine oils (biomaterials) as asphalt binder rejuvenators in combination with RAS represents an attractive aspect to be studied in detail.

Microbial Dynamics and Quality Monitoring in Biopharmaceutical Production

AbstractProkaryotic cells are pivotal in meeting the global demand for biopharmaceuticals. However, challenges such as the absence of advanced technology for real‐time monitoring, standardized testing methodologies, and quality risk assessment of microbial activity have led to increased production costs, delays, and shortages of biopharmaceutical products. A thorough understanding of how biomolecule production interacts with microbial population structure and function is vital for improving continuous manufacturing and process automation. In this review, we discuss the current microbiological techniques that meet good manufacturing practice requirements in industrial settings, explore the advantages of monitoring and measuring biomass growth efficiency and turnover rates beyond regulatory criteria for product release, and provide a critical assessment of the current state of knowledge on bioassays and engineering tools for biomolecule yield measurement and monitoring. Furthermore, we identify areas for future development, potential applications, and the need for interdisciplinary innovation to drive future research, including advancing bioassays for biopharmaceutical wastewater risk.

Testing ADAS/ADS – from critical scenarios to automated testing oracles

AbstractAutomated and autonomous driving systems are increasingly integrated into modern vehicles to support the vision of safe, efficient, and comfortable transportation. Given the complexity of these systems, thorough testing and close monitoring of their behavior is inevitable to prevent hazardous situations and unexpected behaviors. This paper presents different approaches for testing ADAS/ADS, focusing on generating critical scenarios for virtual validation and monitoring approaches applied during operation. Specifically, we provide a comprehensive overview of our previous work on combinatorial and search-based testing methodologies, highlighting their application in generating robust test suites. Additionally, we summarize our work on intelligent monitoring approaches to detect operational issues. Our findings emphasize the necessity of advanced testing solutions and continuous monitoring to identify and mitigate potential failures, demonstrating their applicability in enhancing the safety and trustworthiness of ADAS/AD.

3D Printed Orthodontic Aligners—A Scoping Review

This scoping review aims to provide a comprehensive summary of the current literature on 3D-printed orthodontic aligners. It was conducted following the Preferred Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines. An electronic literature search was conducted across the PubMed, Embase, and Web of Science databases. After applying the inclusion criteria, a total of 46 eligible studies published until September 2024 were selected for qualitative synthesis. To date, scientific evidence is primarily available for Tera Harz TC (Graphy, Seoul, Republic of Korea), which is the only studied material approved for orthodontic tooth movements. Although additional materials were identified during the literature search, there is a lack of scientific studies regarding their characteristics and clinical use. This review highlights that while material properties and biocompatibility are of critical importance, the clinical efficacy and long-term safety of 3D-printed aligners require further investigation. Many studies exhibit significant variability in testing methodologies, making substantiated comparisons challenging. Moreover, the existing literature primarily comprises in vitro studies, with limited clinical trials assessing the effectiveness of 3D-printed aligners. Given the current gaps in knowledge and the evolving nature of this field, further well-designed controlled clinical studies are necessary to evaluate the clinical performance and safety of 3D-printed aligners. The findings underscore the need for standardized protocols and comprehensive reporting to enhance the reliability of future research in this area.

Transcriptomic characterization of 2D and 3D human induced pluripotent stem cell-based in vitro models as New Approach Methodologies for developmental neurotoxicity testing

Transcriptomic characterization of 2D and 3D human induced pluripotent stem cell-based in vitro models as New Approach Methodologies for developmental neurotoxicity testing

The research of thermal environment test methodology for the Mars probe product

Abstract In order to ensure the success of the Mars exploration mission, it is necessary to accurately simulate the unique environment on the surface of Mars in a ground test and verify the effectiveness of the thermal control measures of the Mars rover. This paper proposes a thermal balance test method that can simultaneously simulate environmental factors such as Martian surface gas atmosphere, wind speed, pressure, solar radiation, and atmospheric temperature. This proposed test method meets the thermal design verification requirements of component-level products. Compared with similar large-scale facilities, the test cost is low, and the implementation efficiency is high. Furthermore, the influence of the Martian wind field on the surface temperature distribution of the product under both the Martian day and night environment was investigated using the proposed test method. The research results show that although the atmospheric pressure on the surface of Mars is much lower than the surface of the Earth, the Martian wind will still form forced convection heat transfer on the surface of the probe and its auxiliary products, which will affect the heat distribution of the products. In the thermal control design of the products, it is necessary to consider the impact of all the above environmental factors and carry out corresponding comprehensive environmental test verification.

Quaternary Ammonium Salt-Derived Carbon Dots for Antibacterial Efficacy and Tetracycline Sensing

Bacterial infections pose a significant threat to global health, necessitating the development of novel antibacterial materials. Tetracycline antibiotics (CTC, OTC, TC) are low-cost and widely abused in recent years. However, they were easily absorbed by the human body and long-term exposure to tetracycline could contribute to some adverse reactions and diseases. So there is a need for novel antimicrobial agents and a rapid, sensitive detection method of tetracycline antibiotics. In this study, we synthesized three carbon dots (CDs1, CDs2, CDs3) from quaternary ammonium salts via a hydrothermal method. Antibacterial assays against Staphylococcus aureus and Escherichia coli demonstrated their potent antibacterial activity with minimum inhibitory concentrations(MIC) determined as 39 μg/mL, 78 μg/mL, and 9.8 μg/mL, respectively. Notably, CDs3 exhibited the highest antibacterial effectiveness, attributed to its smaller size and higher chlorine content compared toCDs1 and CDs2. Additionally, CDs1, characterized by its high fluorescence quantum yield and stability, demonstrated remarkable specificity and robust anti-interference capabilities in detecting tetracycline antibiotics, including chlortetracycline (CTC), oxytetracycline (OTC), and tetracycline (TC). Leveraging the internal filtration effect mechanism, CDs1 exhibited detection limits of 0.18 μmol/L for CTC, 0.15 μmol/L for OTC, and 0.13 μmol/L for TC, respectively. The effectiveness of this detection method was further confirmed through validation in real milk samples, confirming the practical utility of CDs1 in food safety testing. The low toxicity of carbon dots were synthesized using a simple one-step hydrothermal method, which was fast, cost-effective, and easy to achieve large-scale production. Our findings underscore the potential of CDs derived from quaternary ammonium salts, demonstrating promising performance in antibacterial applications and providing insights into food safety testing methodologies.