Joint Test Research Articles

Genome-wide association study reveals shared and distinct genetic architecture underlying fatty acid and bioactive oxylipin metabolites in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL).

Bioactive fatty acid-derived oxylipin molecules play key roles mediating inflammation and oxidative stress. Circulating levels of fatty acids and oxylipins are influenced by environmental and genetic factors; characterizing the genetic architecture of bioactive lipids could yield new insights into underlying biology. We performed a genome wide association study (GWAS) of 81 fatty acids and oxylipins in 11,584 Hispanic Community Health Study/Study of Latinos (HCHS/SOL) participants with genetic and lipidomic data measured at study baseline (58.6% female, mean age = 46.1 years (standard deviation 13.8)). Additionally, given the effects of central obesity on inflammation, we examined interactions with waist circumference using two-degree-of-freedom joint tests. Thirty-three of the 81 oxylipins and fatty acids were significantly heritable (heritability range: 0-32.7%). Forty (49.4%) oxylipins and fatty acids had at least one genome-wide significant (p< 6.94E-11) variant resulting in 19 independent genetic loci. Six loci (lead variant minor allele frequency [MAF] range: 0.08-0.50), including desaturase-encoding FADS and OATP1B1 transporter protein-encoding SLCO1B1, exhibited associations with two or more fatty acids and oxylipins. At several of these loci, there was evidence of colocalization of the top variant across fatty acids and oxylipins. The remaining loci were only associated with one oxylipin or fatty acid and included several CYP loci. We also identified an additional rare variant (MAF = 0.002) near CARS2 in two-degree-of-freedom tests. Our analyses revealed shared and distinct genetic architecture underlying fatty acids and oxylipins, providing insights into genetic factors and motivating work to characterize these compounds and elucidate their roles in disease.

Detection of Diffusion Interlayers in Dissimilar Welded Joints in Processing Pipelines by Acoustic Emission Method

The paper considers the neural network application to detect microstructure defects in dissimilar welded joints using the acoustic emission (AE) method. The peculiarity of the proposed approach is that defect detection is carried out taking into account a priori information about the properties of the AE source and the acoustic waveguide parameters of the testing structure. Industrial process pipelines with dissimilar welded joints were studied as the testing object, and diffusion interlayers formed in fusion zones of welded joints were considered microstructure defects. The simulation of AE signals was carried out using a hybrid method: the signal waveform was determined based on a finite element model, while the amplitudes of AE hits were determined based on a physical experiment on mechanical testing of dissimilar welded joints. Measurement data from industrial process pipelines were used as noise realizations. As a result, a data sample was formed that considered the parameters of the AE source and the parameters of the acoustic waveguide with realistic noise parameters and a signal-to-noise ratio. The proposed method allows for a more accurate determination of the waveform, spectrum, and amplitude parameters of the AE signal. Greater certainty in the useful signal parameters allows for achieving a more accurate and reliable classification result. When using a backpropagation neural network, a percentage of correct classification of more than 90% was obtained for a data set in which the signal-to-noise ratio was less than (−5 dB) in 90% of cases.

Cervical spine sensorimotor deficits persist in people post-concussion despite minimal symptoms

Background The mechanisms of a concussion place stress on the cervical spine like that of a whiplash event, which can result in cervical spine dysfunction. This study aimed to determine if underlying cervical spine mobility and sensorimotor function deficits occur in individuals who are post-concussion with near resolution of symptoms. Methods Twenty-five participants with a self-reported concussive event within a year (PC group: post-concussion 157 + 120 d, 9 men, age: 25 ± 8 yr) and 26 comparable peers (Peer group, 9 men, age: 25 ± 7 yr) were tested. The Post-Concussion Symptom Scale (PCSS) quantified residual concussion symptoms. Participants completed cervical joint position error (JPE) and cervical spine joint mobility tests blinded from each other. Group mean differences were analyzed using t-tests. Results The PC group had minimal symptoms (PCSS = 6.8 ± 6.5) but substantial differences in JPE tests compared to the Peer group (PC = 7.4 ± 1.8 cm; PG = 5.6 ± 1.1 cm; p < .001). Those PC participants with pain during joint testing (n = 15) had worse JPE (Painful = 8.1 ± 1.8 cm, No-pain = 6.3 ± 1.6 cm; p = .02) and less averaged lower cervical spine joint mobility compared to PC participants without pain (Painful = 0.66 ± 0.22, No-pain = 0.87 ± 0.19; p = .02, Normal motion = 1.0). Conclusion Following a concussion, it is a reasonable recommendation to screen the cervical spine to identify impairments in joint mobility and JPE that contribute to neck dysfunction.

Evaluating the moisture absorption percentage in the adhesive layers of carbon fiber reinforced plastic joints via electromagnetic induction testing and diffusion analysis

In this study, we propose a method that combines moisture absorption analysis and electromagnetic induction testing (EIT) to detect weak bonds formed in the adhesive layers of carbon fiber reinforced plastic (CFRP) joints due to moisture absorption. Although EIT is effective for assessing CFRP joint adhesive moisture absorption, early-stage detection of weak bonds is challenging. Our method addresses this by combining calculations of moisture absorption percentage via the diffusion equation and EIT-based measurements. First, we conducted diffusion analysis using the finite difference method (FDM). The moisture absorption percentage calculated via the FDM was validated by comparing it with the results of the moisture absorption tests of the CFRP adhesive joints, and good agreement was observed. Second, EIT was applied to the CFRP adhesive joints, and the experimental results indicated that the moisture absorption percentage of the CFRP joint can be qualitatively evaluated using EIT. Finally, the moisture absorption of the CFRP joint adhesive layer was quantitatively evaluated by combining the results of EIT on the CFRP joints with those of the numerical analysis. Therefore, the proposed method enables the previously difficult quantitative evaluation of the early-stage moisture absorption percentage of CFRP joint adhesive layers and is effective for the detection of weak bonds created by moisture absorption in CFRP joints.

A SPECIALIZED SYSTEM FOR IN VITRO TEST OF ANATOMIC GLENOIDS BASED ON ASTM F2028-14

Glenoid loosening, primarily induced by the “rocking horse” phenomenon from humeral head load on the glenoid rim, is the foremost complication and cause of failure in anatomic total shoulder arthroplasty. The dynamic load exerted by universal fatigue testing machines significantly deviates from the standard ASTM F2028-14 in the rocking test. To accurately conduct the in vitro loosening test on anatomic glenoids, a specialized system and customized test methods are developed to achieve anatomic glenoid rocking and subluxation tests. The horizontal and vertical loading can be achieved synchronously or asynchronously by two self-developed high-performance electromagnetic linear motors. In addition, the subluxation tests on anatomic glenoids are verified by finite element simulation. The results show that the subluxation load and translation of anatomic glenoids in the subluxation tests are consistent with those in numerical simulations. The error of the applied axial force in the rocking tests is only 5[Formula: see text]N, strictly meeting the standard of ASTM F2028-14. During the rocking tests, the system runs smoothly and the software works well, indicating the feasibility of the in vitro shoulder joint test system. This study provides an approach to accurate dynamic evaluation of glenoid loosening or disassociation.

Adhesive paperboard connections in architectural applications: modelling, characterization, and performance assessment

ABSTRACT Paper-based elements have been researched as cheap and pro-ecological building materials for several decades and bonding is the most widely used method of joining them. However, adhesives may increase the cost, weight, and environmental impact of the component. The suitability of different adhesive types for paper-based building component bonding has not yet been researched. This work evaluates the properties of six types of commercially available adhesives – polyvinyl acetate, dextrin, and synthetic rubber. The results of single-lap tensile tests served as the input for a Goland–Reissner model of adhesive stresses. The elastic properties of the adhesives were estimated based on tensile test results – Shear modulus ranging from 0.626 to 1.097 MPa and Young’s modulus from 0.703 to 2.940 MPa. The modelled shear strength ranged from 1.1922 to 1.6115 MPa and the peel strength from 0.3265 to 0.5894 MPa. Recommendations for adhesive use in paper-based building elements are formulated. Polyvinyl acetate adhesives may be recommended for general use; however, the use of starch/dextrin adhesives should not be neglected. The presented work successfully demonstrates a methodology to obtain properties of adhesives for the mechanical assessment of the bonds from simple tensile tests of single-lap joints.

An improved constitutive model for rapid fatigue properties evaluation based on fatigue damage entropy

A constitutive model, which reflects the non-linear response association between microstructural motion and thermodynamic entropy production, is improved in this study. Two critical stress amplitudes associated with two microstructural movement mechanisms are considered in the improved constitutive model. The determination procedures for the parameters of the presented model are developed. Entropy generation data from three materials computed by two calculation methodologies, collected from the experiment and literature, are used to validate the improved model. Subsequently, a rapid fatigue life estimation method is proposed by using the accumulated entropy corresponding to fatigue damage, i.e. FFE, related to irreversible inelastic microstructural motion. Fatigue tests of welded joints fabricated by Q310NQL2 and Q345NQR2 steels, Q235 steel specimens, as well as experimental data, stainless steel specimens, collected from the literature, are employed to determine the values of the parameters of the developed model. The model is then used to forecast the S–N curve of butt joints with a 50% survival probability, and on this basis, the S–N curve with a certain confidence level is well estimated by the improved statistical method. This enhanced model may offer a fast forecast of the P–S–N curve at a certain confidence level within a limited set of tested data ranges.

Design and implementation of a ground detection system for HERD-TRD front-end electronics

The Transition Radiation Detector (TRD) is a critical component of the High Energy Cosmic Radiation Detection (HERD) experiment, calibrating the electromagnetic calorimeter at the TeV energy range and observing X-rays in the all-sky survey. To support HERD-TRD test, a comprehensive ground detection system featuring a data acquisition (DAQ) board and host computer software was designed and implemented. The DAQ system manages data from six front-end electronics (FEE), totaling 768 detector channels, using an LVDS interface for high-speed scientific data transfer and an RS422 interface for command and telemetry. Gigabit Ethernet and mini USB enable real-time communication with the host computer. Host computer software developed on the QT platform efficiently manages data acquisition, storage, and display. The DAQ board offers a compact circuit design and complete functionality, and the host software provides an intuitive user interface. The DAQ board and host computer software have been tested to meet the design requirements. Performance tests show that the system realizes a stable data transfer rate of 360 Mbps over Gigabit Ethernet and 55 Mbps from the FEE to the DAQ board. The system has minimal noise and runs continuously for a week without data loss. In addition, a joint test with TRD using the 55Fe radioactive source was performed, and the particle signal was correctly acquired.

Fabrication and Test of Indium-Plated Solder Welding NbTi Superconducting Joint

Fabrication and Test of Indium-Plated Solder Welding NbTi Superconducting Joint

Heat‐Treatment and Water Immersion Effect on the Mechanical Properties and Joint Strength of 3D‐Printed Polylactic Acid Parts

ABSTRACTThis paper investigates the effect of short‐time water immersion (WI) and heat‐treatment (HT) post‐processes on the mechanical properties and joint strength of printed polylactic acid (PLA) parts with various raster angles. Using these post‐processing methods to enhance the joint strength of printed PLA parts could be deemed as the novelty and the contribution of the current study. The WI and HT of the tensile test specimens and the adherends of the bonded joints were carried out at 21°C and 90°C, respectively. Depending on the raster angle, the tensile strength of the heat‐treated specimens was about 11%–43% higher than that of the untreated specimens. Interestingly, it was found that WI had a more significant effect on the strength of printed parts than HT. In the case of WI, the tensile strength was increased by about 27%–57% as compared to the untreated specimens. Joint tests revealed that HT and WI exerted a similar positive effect on the strength of the joints. The findings highlighted that short‐time WI is at least as effective as HT in increasing the tensile and joint strengths of 3D‐printed PLA parts.

Research on safety control technology of high-speed railway combined test based on threatening event analysis

PurposeSafety management is a key point and poses a challenge in joint testing. To detect and address potential accidents' hidden dangers early, this paper conducts research on the safety control technology for high-speed railway joint tests by incorporating the concept of hazardous events.Design/methodology/approachAiming at ensuring the safety of high-speed railway combined inspections and trials, this paper starts from the dual prevention mechanism. It introduces the concept of threatening events, defines them and analyzes the differences between threatening events and railway accidents. The paper also proposes a cause model for threatening events in high-speed railway combined inspections and trials, based on three types of hazard sources. Furthermore, it conducts research on the control strategies for these threatening events.FindingsThe research on safety control technology for high-speed railway combined operation and testing, based on the analysis of threatened events, offers a new perspective for safety management in these operations. It also provides theoretical and practical support for the transition from passive prevention to active risk pre-control, which holds significant theoretical and practical value.Originality/valueThe innovation mainly includes the following three aspects: (1) Building on the traditional dual prevention mechanism, which includes risk hierarchical management and control as well as hidden danger investigation and management, a triple prevention mechanism is proposed. This new mechanism adds the management of threatening events as the third line of defense. The aim is to more comprehensively identify and address potential security risks, thereby enhancing the efficiency and effectiveness of security management. (2) In this paper, the definition of a railway threatening event is clarified, and the causative model of a high-speed railway threatening event based on three kinds of danger sources is proposed. (3) This paper puts forward the control strategy of the high-speed railway combined operation and trial, which includes five key links: identification, reporting, analysis, rectification and feedback, which provides a new perspective for the safety management of the high-speed railway combined operation and trial and has important theoretical and application value.

A point-of-care testing strip based on a rationally designed antigen and antibody for fast and reliable Diquat poisoning detection: Ready for clinical application

AbstractDiquat (DQ) is a nonselective quick-acting herbicide, which can directly contaminate humans and the environment during improper use and production. The early diagnosis of DQ poisoning allows for patients to receive timely treatment. Here, a novel monoclonal antibody was screened based on the rational design and synthesis of a DQ hapten and complete antigen. With the custom-designed anti-DQ antibody, we developed a stable and specific immunochromatographic strip to recognize DQ within 10 ∼ 15 min in various biological samples. The test strips could recognize DQ at concentrations as low as 20 ng/mL and be read by the naked eye, reaching the detection level of liquid chromatography-mass spectrometry. Moreover, quantitative methods involving the use of immunochromatographic strips and ELISA were developed to continuously monitor DQ concentrations. DQ and paraquat (PQ) joint test strips were developed to simultaneously measure DQ and PQ. Notably, the clinical performance of the proposed test strips was evaluated in multiple hospitals and public health agencies. Taken together, our study provides the first clinical DQ-targeted colloidal gold immunochromatographic test strips with excellent performance, which are expected to be useful for clinical practice, environmental monitoring, food safety and scientific research.

Non-Destructive Testing of Joints Used in Refrigerated Vehicle Bodies

Non-Destructive Testing of Joints Used in Refrigerated Vehicle Bodies

Joint testing of rare variant burden scores using non-negative least squares

Gene-based burden tests are a popular and powerful approach for analysis of exome-wide association studies. These approaches combine sets of variants within a gene into a single burden score that is then tested for association. Typically, a range of burden scores are calculated and tested across a range of annotation classes and frequency bins. Correlation between these tests can complicate the multiple testing correction and hamper interpretation of the results. We introduce a method called the sparse burden association test (SBAT) that tests the joint set of burden scores under the assumption that causal burden scores act in the same effect direction. The method simultaneously assesses the significance of the model fit and selects the set of burden scores that best explain the association at the same time. Using simulated data, we show that the method is well calibrated and highlight scenarios where the test outperforms existing gene-based tests. We apply the method to 73 quantitative traits from the UK Biobank, showing that SBAT is a valuable additional gene-based test when combined with other existing approaches. This test is implemented in the REGENIE software.

Powerful Rare-Variant Association Analysis of Secondary Phenotypes.

Most genome-wide association studies are based on case-control designs, which provide abundant resources for secondary phenotype analyses. However, such studies suffer from biased sampling of primary phenotypes, and the traditional statistical methods can lead to seriously distorted analysis results when they are applied to secondary phenotypes without accounting for the biased sampling mechanism. To our knowledge, there are no statistical methods specifically tailored for rare variant association analysis with secondary phenotypes. In this article, we proposed two novel joint test statistics for identifying secondary-phenotype-associated rare variants based on prospective likelihood and retrospective likelihood, respectively. We also exploit the assumption of gene-environment independence in retrospective likelihood to improve the statistical power and adopt a two-step strategy to balance statistical power and robustness. Simulations and a real-data application are conducted to demonstrate the superior performance of our proposed methods.

Fatigue life prediction method for bolted joints based on equivalent structural stress under tensile–compressive loading

In this study, load amplitude–life (Fa–N) curves were obtained through tensile–compressive fatigue tests of bolted joints. It was observed that the correlation coefficient squared (R2) value of the Fa–N curve with the same geometric and pre-tightening parameters was high, but the R2 value of the Fa–N curve with all the parameters was low, indicating poor correlation and inability to meet the engineering requirements. Therefore, an equivalent structural stress model for the bolted joint was first developed based on a mechanical model with a strict mathematical definition to normalize these Fa–N curves, which considered the bolted joint loads as the input conditions and integrated the geometric and pre-tightening parameters. Subsequently, a classical beam–shell equivalent finite element model of the bolted joint was constructed. The nodal loads in the bolted connection zone were coupled with the forces and moments of the beam element nodes through finite element simulation, and the equivalent structural stress (σs) of the bolted joint was then obtained based on the equivalent structural stress model. Consequently, the equivalent structural stress–life (Ss–N) curve and probabilistic stress–life (P–Ss–N) curve normalized for different Fa–N curves were obtained by fitting the data of σs and N. Lastly, the accuracy of the fatigue life prediction method based on equivalent structural stress was verified by conducting the vibration fatigue test on the bolted joint structure of the subway antenna bracket.

A common component of Fama and French factor variances

This is the first study that explicitly explores the risk of the Fama and French equity factors in terms of their realized variances. Our results show that realized factor variances exhibit strong power-law behavior. A striking commonality is that the power-law exponents are close to α ≈ 2 regardless of which factor variance is analyzed. Notably, our novel joint test designed to test Mandelbrot’s infinite variance hypothesis in the cross-section of realized factor variances shows that the null hypothesis of α = 1.9 cannot be rejected, which further corroborates the evidence that (a) there exist a common component governing factor variance risk, and (b) factor variance risk is statistically undefined. Further evidence derived from co-fractality analysis shows that (c) risk diversification appears to be very limited as factor variances tend to exhibit power-law behavior coincidently. We argue that our study has several theoretical and practical implications—especially due to the fact that factor investing reached $5 trillion in assets under management.

Comparative Analysis of the Performance and Study of the Effective Anchorage Length of Semi-Grouted and Fully-Grouted Sleeve Connection

Based on the insufficient data on bonding performance and effective anchorage length of sleeve grouting in assembled structure. Combining the existing studies, the sleeve grouting joint test for the static unidirectional tensile test was designed, and the influencing factors are reinforcement diameter and reinforcement anchorage length. Then, the failure mode, load-displacement relationship, energy consumption capacity and bearing capacity of the grouting sleeve connection are analysed, and the stress mechanism of the specimen in the one-way tensile state is expounded. This paper considers the actual damage state of the joint, according to the failure of the reinforcement outside the joint and the sleeve; referring to the reinforcement-concrete bond strength research theory, the effective anchorage length formula is proposed. When the steel bar is pulled out, the bond strength and bearing capacity mainly depend on the effective anchorage length. However, when the specimen breaks the steel bar outside the joint, it depends on the material performance of the steel bar itself. The research results of this paper can lay a theoretical foundation for the application of sleeve grouting joints.

Short-term contrarian in the carbon emission market

We consider the short-term contrarian effects in daily data from carbon emission markets. Technical analysis is conducted with three contrarian trading rules on four carbon emission markets of China. Various individual and joint test statistics are developed for testing the contrarian profits from individual trading path as well as a group of trading paths. Empirical evidence shows that the contrarian profits are statistically and economically significant across the technical rules. Particularly, the contrarian moving average group trading generates average returns of 3.8 to 13.8 % per month across the different carbon markets during the period of 2013–2023 and the corresponding Sharpe ratios range from 0.9 to 2.01, while the Sharpe ratios from the buy-and-hold strategy are all below 0.12. Further tests support that the contrarian profits are not eliminated by transaction costs, and not dominated by extreme returns. We also emphasize on the explanations of the contrarian profit. Among the considered variables, the market volatility is the most significant explanatory variable for contrarian profits across four markets, whereas the market illiquidity and non-trading breaks are also significant in certain markets. The finding supports the explanation of the behavioural bias of overreaction for the short-term contrarian effect. Other explanations, including short-selling constraint, clearing stress, price limits, government interventions, etc. are also discussed in the paper.

Experimental study on eccentric compression of the prefabricated columns with a new type of column-column connection node

An assembled building is defined by a construction methodology wherein prefabricated components are fabricated off-site and subsequently assembled at the construction site. This methodology confers cost efficiency, expedites construction timelines, and enhances the quality of the prefabricated components. Furthermore, it mitigates a range of environmental concerns inherent to conventional poured-in-place construction methods. This paper introduces a novel assembled column-column connection node that utilizes a new adhesive potted rebar lap joint. The research was divided into two principal components. Firstly, 18 specimens of adhesive potted rebar lap joints were tested under tension, with the lap length being the variable parameter. Secondly, eccentric compression experiments were conducted on one poured-in-place column and six assembled columns, varying parameters such as stirrup configuration and the length of the post-poured section. The failure modes of the columns, as well as their bearing capacities, deflection, rebar strains, and concrete strains, were analyzed and recorded. The test results revealed the existence of two different failure modes in the tensile tests of adhesive potted rebar lap joints. It was found that the reasonable lap length of the specimen should be no less than 14 times the diameter of the rebar (d). Eq. (15) was employed to estimate the suitable lap length for specimens with different sleeve and rebar diameters. In the failure sections of the prefabricated columns, all failures occurred outside the nodes. Moreover, the mechanical properties of small eccentrically compressed columns were comparable to those of the poured-in-place column. The use of spiral stirrups enhances the bearing capacity of the specimen, and an increase in the length of the post-poured section corresponds to a greater bearing capacity. The lateral deflection of the poured-in-place column generally follows a sinusoidal curve, while the lateral deflection of prefabricated columns in the later stages of loading does not exhibit a sinusoidal pattern. Both align with the assumption of a flat section. The stress performance of adhesive potted rebar lap joints in eccentric columns meets the strength requirements. The inclusion of tenons minimally affects the stress distribution in the node, fulfilling construction specifications. The stress performance of the assembled column nodes is reliable. The proposed adhesive potted rebar lap joint technology, along with the novel prefabricated column-column node, provides significant insights into engineering design and construction applications.