Test Device Research Articles

Study on the Electromigration Organization and Mechanical Properties of Sn2.5Ag0.7Cu0.1RE/Cu Solder Joints

In this study, we designed and manufactured an ideal electromigration testing device for soldering joints to solve the reliability problems caused by temperature and current density changes in the electromigration processes of micro solder joints. We analyzed the effects of temperature and current density on the electromigration β-Sn (single-crystal β-Sn grain) of Sn2.5Ag0.7Cu0.1RE/Cu solder joints, the relationship between the grain orientation and interfacial IMC (intermetallic compound) growth of Sn2.5Ag0.7Cu0.1RE/Cu solder joints, and the mechanical properties of solder joints. The results showed that the angle θ between the c-axis of the β-Sn grain and the current direction for the Sn2.5Ag0.7Cu0.1RE/Cu solder joint gradually decreased to 8.2° when the temperature increased to 150 °C, which accelerated the diffusion of Cu atoms and Cu substrate dissolution. The recrystallization and grain growth of Cu6Sn5 (An intermetallic compound formed by the fusion of copper and tin in a ratio of six to five) grains in the anode region promoted electromigration polarity. Compared with the initial state, the shear strength decreased to 11 MPa, a decrease of 61.3%, the fracture position shifted from the top of the IMC at the cathode interface to the root of the IMC at the cathode interface, and the fracture mode changed from ductile fracture to brittle fracture. With an increase in the current density to 1.1 × 104 A/cm2, θ decreased to 3.2°. In addition, we observed the recrystallization of Cu6Sn5 grains in the anode region and an increase in the grain length and diameter to 6.8–31.9 μm, which further promoted electromigration polarity. Compared with the initial state, the shear strength decreased by 72.5% to 7.8 MPa, and the fracture position shifted from the top of the IMC at the cathode interface to the root of the IMC at the cathode interface. Additionally, the fracture mode changed from ductile to brittle fracture.

Design and Validation of a Testing Device for Sediment-Induced Erosion Based on Similarity Theory

Sediment-induced erosion is a primary cause of failure in the flow-passage components of Francis turbine units. This study adopted the Realizable k–ε turbulence model to numerically simulate the effects of sediment-induced erosion on the guide components of Francis turbines. Specifically, using flow similarity theory, a testing device suitable for studying the sediment-induced erosion behavior of turbine vanes was designed, and the similarity between the flow fields of actual vanes and testing device vanes was validated. The results revealed a high degree of consistency between the near-wall flow velocities and sediment volume fractions experienced by both vanes at 0.5 vane height. For instance, the midsection of the suction side of the stay and guide vanes exhibited relatively stable velocities of 12.5 m/s and 42 m/s, respectively. Further, sediment volume fractions at the leading edge of the stay and guide vanes reached 0.015, respectively, owing to the impact of sediment-laden flow. Overall, the proposed testing device design methodology can predict the operational lifespan of actual vanes and assess the wear resistance of various coating materials. These findings provide valuable scientific guidance for optimizing the design and operation of hydropower plants.

Multiplanar Semicircular New-Generation Implant System Developed for Proximal Femur Periprosthetic Fractures: A Biomechanical Study

Background and Objectives: The study aimed to evaluate a newly designed semicircular implant for the fixation of Vancouver Type B1 periprosthetic femoral fractures (PFFs) in total hip arthroplasty (THA) patients. To determine its strength and clinical applicability, the new implant was compared biomechanically with conventional fixation methods, such as lateral locking plate fixation and a plate combined with cerclage wires. Materials and Methods: Fifteen synthetic femur models were used in this biomechanical study. A Vancouver Type B1 periprosthetic fracture was simulated by osteotomy 5 mm distal to the femoral stem. The models were divided into three groups: Group I (lateral locking plate fixation), Group II (lateral locking plate with cerclage wires), and Group III (new semicircular implant system). All fixation methods were subjected to axial loading, lateral bending, and torsional force testing using an MTS biomechanical testing device. Failure load and displacement were measured to assess stability. Results: The semicircular implant (Group III) demonstrated a significantly higher failure load (778.8 ± 74.089 N) compared to the lateral plate (Group I: 467 ± 68.165 N) and plate with cerclage wires (Group II: 652.4 ± 65.474 N; p < 0.001). The new implant also exhibited superior stability under axial, lateral bending, and torsional forces. The failure load for Group III was more robust, with fractures occurring at the screw level rather than plate or screw detachment. Conclusions: Compared to traditional fixation methods, the newly designed semicircular implant demonstrated superior biomechanical performance in stabilizing Vancouver Type B1 periprosthetic femoral fractures. It withstood higher physiological loads, offered better structural stability, and could be an alternative to existing fixation systems in clinical practice. Further studies, including cadaveric and in vivo trials, are recommended to confirm these results and assess the long-term clinical outcomes.

Validation of Point-of-Care Testing Device for Serum Ferritin Estimation in an Outpatient Facility in India

Validation of Point-of-Care Testing Device for Serum Ferritin Estimation in an Outpatient Facility in India

Plantar cutaneous sensation is independently associated with postural balance and lower limb motor function in older adults: the Shizuoka study.

A relationship between decreased plantar cutaneous sensation and impaired balance function has been reported in patients with peripheral neuropathy and diabetes. This cross-sectional study aimed to investigate the relationship between plantar sensation and postural balance, as well as the association between plantar sensation and sarcopenia-related motor function in community-dwelling older adults. The participants included 1659 community-dwelling older adults with a mean age of 74 ± 5years, of which 43% were male patients. Plantar cutaneous sensation thresholds were assessed using an automatic plantar sensation testing device. Postural balance was measured using one-leg standing (OLS) time. Grip strength, five-time sit-to-stand (STS) time, and normal gait speed were measured as components of muscle strength and physical function related to sarcopenia. The skeletal muscle mass index (SMI) and leg phase angle were obtained using bioelectrical impedance analysis. Age, sex, body mass index, and leg phase angle, but not SMI and grip strength, were independently associated with the plantar sensation threshold. Plantar sensation threshold was independently associated with the OLS time (P = 0.001) and STS time (P = 0.001) after adjusting for potential confounders. No significant association was found between plantar sensation threshold and normal gait speed (P = 0.741). Plantar sensation was independently associated with postural balance and lower limb function in community-dwelling older adults. The assessment of plantar sensation could be useful for identifying factors contributing to poor postural balance and lower limb motor function.

Test device, method, and result analysis for impulse breakdown characteristics of frozen soil in high altitude regions up to 5500m

Test device, method, and result analysis for impulse breakdown characteristics of frozen soil in high altitude regions up to 5500m

A Soil Erosion Testing Device for Measuring Critical Shear Stress and Erosion Rate

A Soil Erosion Testing Device for Measuring Critical Shear Stress and Erosion Rate

APPLICATION OF GUIDED INQUIRY MODEL ASSISTED BY AUDIO-VISUAL MEDIA TO IMPROVE INQUIRY SKILLS IN SCIENCE LEARNING

This study examines the improvement of students' inquiry skills facilitated through the implementation of a guided inquiry learning strategy accompanied by the use of audiovisual media, and measures the magnitude of the improvement of these skills after the implementation of this strategy. This study adopted a nonequivalent control group design as a type of quasi-experiment. All students in grade VIII at SMP Negeri 1 Garung became the target population. The selected sample subjects were VIII C class as the treatment group, and VIII A class as the comparison group with non-random sample selection method. The instruments utilized in this research are test devices, observation sheets, and documentation. The results of the analysis showed that the inquiry skills of students who received a guided inquiry strategy accompanied by audiovisual media had a higher average than those who only received a guided inquiry strategy without audiovisual media. The results of the comparison test of the means of two independent groups with a significance level of 5% resulted in a significance value of 0.000 <0.05, so ha is accepted while ho is rejected. Testing with the N-Gain metric showed that the average score of the treatment group was 0.75, which was in the high category, while the average score of the comparison group was 0.68, which was in the medium category. Based on this analysis, it can be seen that the guided inquiry strategy with audiovisual media support is effective in improving students' inquiry skills.

The Role of Retirement Goal Clarity in Mediating Social Support, Future Perspective and The Direct Effect of Financial Literacy, Health Literacy On Retirement Planning

The purpose of this study is to determine the influence of financial literacy, health literacy, and social support, as well as a future perspective mediated by clarity of retirement goals on retirement planning. This research was conducted on employees of media companies in the city of Jogjakarta from May to June 2024, with a total of 59 respondents. This research was carried out using quantitative methods and using the Smart PLS-3 test device. The results of this study are that financial literacy, health literacy, and clarity of retirement goals have a positive and significant effect on retirement planning. Social support and future perspectives have no effect on retirement planning. The variable of clarity of retirement goals in this study is proven to be able to mediate the influence of social support and future perspectives on retirement planning.

High Performance of Cs2AgBiBr6 Perovskite-based Photodetectors by Adding DEAC.

Perovskite-based photodetectors (PDs) are broadly utilized in optical communication, non-destructive testing, and smart wearable devices due to their ability to convert light into electrical signals. However, toxicity and instability hold back their mass production and commercialization. The lead-free Cs2AgBiBr6 double perovskite film, promised to be an alternative, is fabricated by electrophoretic deposition (EPD), which compromises film quality. Herein, we improved the quality of the Cs2AgBiBr6 films and the performance of PDs by adding N-acetylethylenediamine (DEAC) to Cs2AgBiBr6 perovskite precursor for EPD, in which the ligand DEAC provides a pair of lone electrons to Bi3+, forming coordinate covalent bonds. The optimized PDs have high detectivity, up to 4.4×1012 Jones, and high stability in the air. The high-performance, flexible Cs2AgBiBr6 perovskite PDs were fabricated on this basis, it also achieved the detectivity up to 3.2×1012 Jones with excellent bending cycle stability. These results propose a feasible approach to improving the crystallization of double perovskite thin films by introducing ligands during the EPD process. Furthermore, they demonstrate enhanced optoelectronic performance, indicating that this method is also applicable to halide perovskites, offering an effective strategy to improve their film quality.

Isothermal nucleic acid amplification for monitoring hand-foot-and-mouth disease: current status and future implications.

With the global prevalence of the hand-foot-and-mouth disease (HFMD) epidemic, the development of reliable point-of-care testing (POCT) is crucial for the timely identification and prevention of outbreaks. Isothermal nucleic acid amplification techniques (INAATs) have attracted much attention because of their high efficiency for rapid diagnosis. In this work, we systematically summarize the current status of INAATs for HFMD and discuss advantages and drawbacksof various INAATs for HFMD. The INAATs for HFMD detection mainly include loop-mediated isothermal amplification (LAMP), simultaneous amplification and testing (SAT), and recombinase polymerase amplification (RPA). Among them, LAMP has excelled in several diagnostic metrics and has made significant progress in the field of POCT. SAT has been effective in overcoming the problem of RNA degradation. RPA is suited for on-site testing due to its rapid amplification rate and low reaction temperature. In addition, this study explores the potential of INAATs in lateral flow strips (LFS) test and microfluidic devices for HFMD. LFS is typically used for qualitative analysis and supports multiple detection. Microfluidics can integrate necessary processes of sample pre-processing, amplification, and signal output, enabling high-throughput qualitative or quantitative detection and demonstrating the potential of monitoring HFMD. We hope the current work will provide insights into INAATs for monitoring HFMD and serve as a reference for the implementation of on-site EV detection for public health.

Enhancing Anemia Detection With Non-invasive Anemia Detection With AI (NiADA): Insights From Clinical Validations and Physician Observations.

Background Anemia, a critical public health issue, affects nearly two billion people globally. Frequent monitoring of blood hemoglobin levels is essential for managing its burden. While point-of-care testing (POCT) devices facilitate hemoglobin testing in resource-limited settings, most are invasive and have inherent limitations. The Non-Invasive Anemia Detection App (NiADA) (Monere, UT) offers a non-invasive alternative, utilizing artificial intelligence (AI) to estimate hemoglobin levels from images of the lower eyelid. This low-cost, real-time solution employs a custom computer vision deep-learning algorithm for hemoglobin levels, offering significant potential for early diagnosis and management of anemia. Methods This study evaluated NiADA in two phases. In the first phase, its performance was compared to laboratory measurements and the minimally invasive POCT device, Hemocue Hb 301. In this study, the current version of NiADA version 2 (V2)is also compared against the previous version of NiADA version 1 (V1) to show the improvement in the last six months. In the second phase, NiADA's results were compared against hemoglobin estimations made by a group of medical professionals, as well as against lab analyzers. For both phases, NiADA performance was evaluated using the Bland-Altman plot, regression coefficients, percentage of acceptable limit, Pearson correlation coefficient, andLin's concordance correlation coefficient. Results The mean difference between NiADA-V2 and laboratory-estimated hemoglobin values was -0.11 g/dL, with limits of agreement (LOA) ranging from +2.86 to -2.64 g/dL, where the upper limit is comparable with HemoCue. The NiADA-V2-acceptable range (percentage of samples falling within ±1 g/dL absolute error) increased to 54% compared to 40% in NiADA-V1. Additionally, NiADA outperformed medical professionals, showing a mean difference of 0.07 g/dL compared to medical professionals' 0.42 g/dL. Conclusion NiADA, as a non-invasive application, exhibits performance comparable to minimally invasive tools and other POCT devices. Its accuracy exceeds that of medical professionals, making it a viable option for anemia screening and monitoring, particularly in community medicine and regions with limited healthcare resources.

Experimental Study on the Effects of Dynamic High Water Pressure on the Deformation Characteristics of Limestone

Difficulty in clarifying the deformation characteristics of deep rocks under a high water pressure environment is a technical bottleneck restricting the safe operation of large hydropower stations. In order to study the effect of reservoir water level changes on the mechanical behavior of deep limestone, a series of mechanical tests were conducted under different dynamic high water pressure environments using a self-developed hydraulic loading test device. The test results show that the unsaturated limestone always undergoes compressive deformation during the linear increase in external water pressure, and the saturated limestone changes its deformation state from compression to expansion during the linear decrease in external water pressure. The stress–strain curve of limestone shows apparent hysteresis characteristics during the cyclic increase and decrease in external water pressure. Overall, the rock strain rate showed a significant negative correlation with the external water pressure, and the rock deformation modulus showed a certain positive correlation with the external water pressure. During hydraulic loading, saturated rocks had a smaller range of variation in the strain rate and deformation modulus and were more resistant to deformation than unsaturated rocks. Limestone was subjected to both external water pressure and internal pore water pressure in a cyclic cycle, where pore water pressure promotes pore creation and expansion, while external water pressure prevents water from degrading the pore structure. The periodic change of water pressure has a significant influence on rock mechanics and deformation behavior, and the rock mass will undergo elastic deformation, plastic deformation, and even fracture. Further study of this deformation rule can provide a more accurate theoretical basis for the safe operation of water conservancy projects.

Development and clinical validation of photochemical biosensors for monitoring hemoglobin, blood lipids and uric acid in plateau areas.

High-altitude regions are prone to plateau erythrocytosis due to unique geo-climatic conditions such as low oxygen, high altitude, and low temperatures, with significantly higher incidences of hyperlipidemia and hyperuricemia compared to lowland areas. However, the extreme environmental conditions at high altitudes and the elevated hematocrit levels in blood samples from these populations present significant challenges to the applicability of existing point-of-care testing (POCT) devices. This study describes the development, early clinical validation, and potential clinical impact of three portable, paper-based photochemical biosensing platforms specifically designed for use at high altitudes to monitor hemoglobin, lipids, and uric acid in blood samples. To systematically evaluate the performance of these sensors, 154 fresh venous blood samples from three distinct altitudes were tested and compared with a reference measurement system, alongside an extensive evaluation for the first time of the suitability of various commercially available POCT devices, including these platforms, for use in high-altitude environments. The results demonstrated that the accuracy and concordance between the developed platforms and the reference system were consistently above 95%. Additionally, concordance remained above 95% when the same samples were tested at varying altitudes (4500 m to 3650 m and 4800 m to 3650 m). All of this indicates that the sensing platform provides high accuracy and reliability for testing in high-altitude environments. It holds promise for broader application in the screening and management of chronic diseases in high-altitude and other extreme environments, and for advancing the use of bedside testing technology in resource-limited settings.

Conceptual project of a center for testing technologies and technical devices for glacier drilling

The implementation of drilling projects in Antarctica requires comprehensive research and development work to study the processes of interaction between drilling equipment and ice and test devices designed for ice drilling. Testing facilities with artificial ice are essential for conducting this type of research. The article presents an analysis of the existing experimental stand projects, which identified a common drawback — inability to recreate a structure of atmospheric ice and thermobaric conditions similar to those in boreholes drilled in Antarctica. The authors propose the conceptual project of a сenter for testing technologies and technical devices for glacier drilling. The сenter is to be located on two sites: the first — on the “Sablino” educational and scientific testing ground of Saint-Petersburg Mining University in the Leningrad Region (Russia), the second — at the drilling complex of 5G borehole at Vostok station in Antarctica. The implementation of the project will allow conducting experimental research and testing, using both shallow artificial ice wells and deep boreholes in the Antarctic glacier. In addition, it will allow maintaining the drilling complex and 5G borehole in a good technical condition.

凹杆式薯土分离装置仿真分析与优化

The limited separation efficiency of potato-soil separation equipment in the southern potato planting areas is attributed to the high viscosity of the soil. To enhance the performance of the lifting chain separation device, a concave bar was designed. Structural parameters influencing the efficiency of potato-soil separation by bars were determined through kinetic analysis during the separation and transportation of potato-soil mixtures. Both a potato simulation model and a sticky soil simulation model were developed. Simulation tests indicated that the concave bar outperforms the straight bar in separation efficiency. Key factors investigated include the angle of the concave side, the width of the concave bar, the depth of the concave bar, and the installation angle. Orthogonal simulations were conducted using separation efficiency and the maximum force on potatoes as evaluation metrics. The results demonstrated that with a concave side angle of 15°, a concave bar width of 450 mm, a concave bar depth of 60 mm, and an installation angle of 30°, the separation efficiency of the potato-soil mixture reached 79.7%, with a maximum force on potatoes of 35.218 N, achieving the highest separation efficiency. Based on these results, test devices were constructed, and field tests were performed. The field test results showed a damage rate of 1.58%, a potato epidermal injury rate of 1.03%, and a loss rate of 2.87%. These results comply with national standards and validate the reliability of the simulation findings.

MeDeT: Medical Device Digital Twins Creation with Few-shot Meta-learning

Testing healthcare Internet of Things (IoT) applications at system and integration levels necessitates integrating numerous medical devices. Challenges of incorporating medical devices are: (i) their continuous evolution, making it infeasible to include all device variants, and (ii) rigorous testing at scale requires multiple devices and their variants, which is time-intensive, costly, and impractical. Our collaborator, Oslo City’s health department, faced these challenges in developing automated test infrastructure, which our research aims to address. In this context, we propose a meta-learning-based approach (MeDeT) to generate digital twins (DTs) of medical devices and adapt DTs to evolving devices. We evaluate MeDeT in Oslo City’s context using five widely-used medical devices integrated with a real-world healthcare IoT application. Our evaluation assesses MeDeT’s ability to generate and adapt DTs across various devices and versions using different few-shot methods, the fidelity of these DTs, the scalability of operating 1000 DTs concurrently, and the associated time costs. Results show that MeDeT can generate DTs with over 96% fidelity, adapt DTs to different devices and newer versions with reduced time cost (around one minute), and operate 1000 DTs in a scalable manner while maintaining the fidelity level, thus serving in place of physical devices for testing.

High-precision chemical quantum sensing in flowing monodisperse microdroplets.

A method is presented for high-precision chemical detection that integrates quantum sensing with droplet microfluidics. Using nanodiamonds (ND) with fluorescent nitrogen-vacancy (NV) centers as quantum sensors, rapidly flowing microdroplets containing analyte molecules are analyzed. A noise-suppressed mode of optically detected magnetic resonance is enabled by pairing controllable flow with microwave control of NV electronic spins, to detect analyte-induced signals of a few hundredths of a percent of the ND fluorescence. Using this method, paramagnetic ions in droplets are detected with low limit-of-detection using small analyte volumes, with exceptional measurement stability over >103 s. In addition, these droplets are used as microconfinement chambers by co-encapsulating ND quantum sensors with various analytes such as single cells, suggesting wide-ranging applications including single-cell metabolomics and real-time intracellular measurements from bioreactors. Important advances are enabled by this work, including portable chemical testing devices, amplification-free chemical assays, and chemical imaging tools for probing reactions within microenvironments.

Research on the Safety Response Characteristics of Composite Charges Under Shock Wave Loading

AbstractIn this work, reaction intensity diagnostic techniques such as self‐shorting electrical probes and witness plates were used to establish a new large‐scale gap test device, which can be used to effectively study the influence of shock wave pressure, confinement strength, and insensitive explosive layer thickness on the safety response under shock loading. Taking a composite charge consisting of a TATB‐based and an HMX‐based aluminized explosive as an example, the influence of shock wave pressure, shell confinement, and composite charge structure on the reaction intensity was studied in detail. The results show that the reaction intensity of the charge is positively correlated with the shock wave pressure, increases with the shell confinement strength, and decreases with the insensitive explosive layer thickness. For the same composite charge structure and confinement strength, the reaction intensity level of the charge increases with the shock pressure. When PBX‐5 is 40 mm thick and PBX‐6 is 60 mm thick, under initial pressures of 6.45, 3.61, and 1.51 GPa, the reaction levels are detonation, deflagration, and no reaction, respectively. Under the same shock pressure, the reaction intensity increases with the confinement strength and decreases with the insensitive explosive layer thickness. For the same composite charge structure and shock pressure (5 mm PBX‐5, 95 mm PBX‐6; 1.51 GPa shock pressure value), when the sleeve is 5 mm steel, 5 mm aluminum, 2 mm steel or weaker, the reaction levels are detonation, detonation, and no reaction, respectively. These results are helpful to the safety design of composite charges.

Evaluating the Responses of the THOR and Hybrid III Small Female ATDs during Frontal Sled Tests

<div>There is evidence to suggest that males and females respond differently in motor vehicle collisions, making it important to study how both sexes respond to vehicle safety systems. The THOR 5th-percentile female (THOR-05F) anthropomorphic test device (ATD) was developed to represent a small female occupant better than the Hybrid III 5<sup>th</sup>-percentile female (HIII-05F) ATD. However, there are few studies in which they have been directly compared. Therefore, the objective of this study was to compare the responses of the two ATDs in matched frontal sled tests simulating a realistic driver seat environment. A 7th-generation Toyota Camry driver seat test buck was used with Camry parts (i.e., 3-point belt, modified seat, steering wheel, airbag, and column). The belt was equipped with a 4-kN load limiter and pretensioner. Rigid foam (65 psi) was used to represent the knee bolster. Thirteen tests were conducted using speeds of 30 and 56 kph. Chest bands were used to measure external chest deflection. Greater neck compression loads, flexion moments, and extension moments were measured in the HIII-05F tests due to different airbag interactions compared to the THOR-05F. Upper neck compression in the HIII-05F was greater for the 30 kph tests than the 56 kph, reinforcing a need to research crashworthiness at lower speeds. Chest deflections were greater in the THOR-05F tests, which was likely due to the more compliant rib cage. External chest deflections indicated that belt routing and breast tissue influenced the location and magnitude of maximum chest deflections. External deflections also indicated that the HIII-05F rib cage might be more coupled bilaterally than the THOR-05F. Femur loads were slightly greater in the THOR-05F, although knee bolster loads were greater for the 56 kph HIII-05F tests. Future work will include conducting matched small female PMHS sled tests.</div>