Strain Field Research Articles

Advances and Challenges in Small Object Detection: A Comparative Analysis of State-of-the-Art Models and Future Directions

Object detection involves the precise and efficient identification and localization of multiple predefined object categories within images. With the advent of deep learning, both the accuracy and efficiency of object detection have significantly improved. Nevertheless, challenges remain in optimizing the performance of mainstream detection algorithms, improving the accuracy of small object detection, enabling multi-class detection, and developing lightweight models. In response to these challenges, this paper provides a comprehensive literature review, analyzing approaches to enhance mainstream object detection by exploring advancements in backbone networks, expanding the visual receptive field, feature fusion, and various training strategies. We also evaluate the performance of leading detection models across established datasets, identifying current limitations and proposing future research directions. These directions include enhancing small object representation in datasets, enriching semantic information, and improving model interpretability. Small object detection remains a critical focus in computer vision, and we anticipate the continued development of algorithms with higher accuracy and efficiency

Detecting and Mapping Peatlands in the Tibetan Plateau Region Using the Random Forest Algorithm and Sentinel Imagery

The extensive peatlands of the Tibetan Plateau (TP) play a vital role in sustaining the global ecological balance. However, the distribution of peatlands across this region and the related environmental factors remain poorly understood. To address this issue, we created a high-resolution (10 m) map for peatland distribution in the TP region using 6146 Sentinel-1 and 23,730 Sentinel-2 images obtained through the Google Earth Engine platform in 2023. We employed a random forest algorithm that integrated spatiotemporal features with field training samples. The overall accuracy of the peatland distribution map produced is high, at 86.33%. According to the classification results, the total area of peatlands on the TP is 57,671.55 km2, and they are predominantly located in the northeast and southwest, particularly in the Zoige Protected Area. The classification primarily relied on the NDVI, NDWI, and RVI, while the DVI and MNDWI were also used in peatland mapping. B11, B12, NDWI, RVI, NDVI, and slope are the most significant features for peatland mapping, while roughness, correlation, entropy, and ASM have relatively slight significance. The methodology and peatland map developed in this work will enhance the conservation and management of peatlands on the TP while informing policy decisions and supporting sustainable development assessments.

Estimation of Dislocation Densities With Nondestructive Scanning Electron Microscope Techniques: Application to Gallium Nitride.

Characterizing threading dislocations (TDs) in gallium nitride (GaN) semiconductors is crucial for ensuring the reliability of semiconductor devices. The current research addresses this issue by combining two techniques using a scanning electron microscope, namely electron channeling contrast imaging (ECCI) and high-resolution electron backscattered diffraction (HR-EBSD). It is a comparative study of these techniques to underscore how they perform in the evaluation of TD densities in GaN epitaxial layers. Experiments reveal that the dislocation line vectors mostly deviate from the growth direction of the film, i.e., ∦ [0001], followed by edge-type dislocations (dislocation lines || [0001]) with insignificant screw character. Furthermore, TDs from the dislocation clusters are characterized as edge- and (edge + mixed)-type TDs. By combining ECCI counting of dislocations and HR-EBSD description of geometrically necessary dislocation density type, it is possible to measure the total TD density and provide the proportion of pure (edge and screw) and mixed TDs. It has also been observed from the analyses of residual elastic strain fields and lattice rotations that it is not possible to identify individual dislocations for the spatial resolution of 50 nm in HR-EBSD. Nevertheless, ECCI and HR-EBSD can be complementarily used to count and characterize the TDs.

Visualization of time-varying effects of strain stress field under eccentric charge structure based on digital image correlation technique

This study determines the influence law of the maximum eccentric uncoupling coefficient on the pressure field distribution at the hole wall through theoretical analysis to investigate the time-varying effect of the maximum eccentric uncoupling coefficient on the stress field of an eccentric charge structure. The findings from the theoretical analysis indicate that when the maximum eccentric uncoupling coefficient (K) is 1, the pressure at the ring hole wall exhibits a circular distribution. As K increases, the pressure distribution at the ring hole wall becomes elliptical, with the elliptical eccentricity increasing progressively. This research employs an ultra-high-speed digital imaging system to assess the impact of the maximum eccentric uncoupling coefficient on the attenuation pattern of the stress field within the elastic vibration region. The results demonstrate that the eccentric charge structure’s effect on the strain field is predominantly observed in its time and strength effects. This is evident in the strain field’s time delay on the non-eccentric side and the fact that the strain field’s strength on this side is weaker than on the eccentric side. In the elastic vibration region, the primary type of radial stress is compressive, whereas the circumferential stress is chiefly tensile. As the measurement point’s distance increases, the peak values of both radial compressive and circumferential tensile stresses diminish exponentially. Interestingly, the attenuation index of the radial stress is notably lower than that of the circumferential stress. The change in the K value has a minimal impact on the attenuation indices of both radial and circumferential stresses. At equal distances from the eccentric side, the peak values of both radial and circumferential stresses display a consistent pattern with K and a linear pattern at distances from the eccentric side and in symmetry. The stress field’s intensity and attenuation pattern on the eccentric side remain largely unaffected by variations in K. Conversely, the stress field attenuation on the non-eccentric side is significantly influenced by K value changes, as is the symmetric side.

StretchView - A Multi-Axial Cell-Stretching Device for Long-Term Automated Videomicroscopy of Living Cells.

Incorporating mechanical stretching of cells in tissue culture is crucial for mimicking (patho)-physiological conditions and understanding the mechanobiological responses of cells, which can have significant implications in areas like tissue engineering and regenerative medicine. Despite the growing interest, most available cell-stretching devices are not compatible with automated live-cell imaging, indispensable for characterizing alterations in the dynamics of various important cellular processes. In this work, StretchView is presented, a multi-axial cell-stretching platform compatible with automated, time-resolved live-cell imaging. Using StretchView, long-term image acquisition of cells in the relaxed and stretched states is shown for the first time (experimental time of 12 h) without the need for human intervention. Homogeneous and stable strain fields are demonstrated for 18 h of cyclic stretching, highlighting the platform's versatility and robustness. As proof-of-principle, the effect of stretching on cell kinematics and spatiotemporal localization of the cell-cell adhesion protein E-cadherin is examined for MDCK cells in monolayer. First evidence of a monotonic increase in junctional E-cadherin localization upon exposure to stretch is presented using live-cell imaging data acquired during cyclic stretching, suggestive of an increase in barrier integrity of the monolayer. These findings highlight the potential of StretchView in providing insights into cell mechanobiology and beyond.

Distributed Fiber Optic Strain Sensing Technology for Monitoring Soil Deformation Induced by Leakage in Buried Water Pipelines: A Model Test Study

Water pipelines in water diversion projects can leak, leading to soil deformation and ground subsidence, necessitating research into soil deformation monitoring technology. This study conducted model tests to monitor soil deformation around leaking buried water pipelines using distributed fiber optic strain sensing (DFOSS) technology based on optical frequency domain reflectometry (OFDR). By arranging strain measurement fibers in a pipe–soil model, we investigated how leak location, leak size, pipe burial depth, and water flow velocity affect soil strain field monitoring results. The results showed that pipeline leakage creates a “saddle-shaped” spatial distribution of soil strain above the pipeline, effectively indicating ground subsidence locations. When only one survey line is arranged, it is preferable to place the optical fiber directly above the pipeline. Surface monitoring fibers primarily detected tensile strain, with more pronounced peak values observed under conditions of larger leak size, higher flow velocity, shallow burial depth, and top-pipe leakage location. Monitoring fibers below the pipeline showed mainly unimodal distribution, with peak strain coinciding with the leak location. The sequential timing of strain changes at different fiber positions enabled the determination of soil seepage direction. This study demonstrates that DFOSS technology can provide important support for the early warning of such geological disasters.

Shape sensing of composite shell using distributed fibre optic sensing

Shape sensing is critically important throughout the lifecycle of composite shell structures, including the design, manufacturing, service, retirement, and reuse phases. In the service phase, for instance, shape-based structural integrity assessments can inform maintenance strategies, significantly reducing regular maintenance costs. To achieve high-fidelity shape sensing, a novel approach is proposed for strain acquisition and interpolation in carbon fibre reinforced polymer (CFRP) shell structures, utilizing distributed fibre optic sensing. This method is designed to enhance the performance of the inverse finite element method (iFEM). The approach introduces a new strain acquisition strategy based on distributed fibre optic sensors and a strain interpolation technique leveraging single image super-resolution (SISR). In the strain acquisition process, a fundamental sensing block capable of capturing both normal and shear strain is employed for sensor network design, which can be easily implemented using fibre optic sensors. The goal of this acquisition strategy is to standardize sensor network design and provide a digital representation, offering novel insights into shape reconstruction for different composite shells across various applications. Utilizing the obtained strain field, the SISR-based strain interpolation method generates a displacement field with enhanced spatial resolution through iFEM. Experimental evaluation of the SISR-based interpolation demonstrates its efficacy in capturing high-fidelity displacement fields in both smooth and non-smooth strain regions of CFRP shell structures. The introduction of SISR in strain field interpolation, for the first time, offers a potential solution to the challenge of interpolating non-smooth strain fields, providing a reference for addressing complex strain field interpolation in practical applications.

Optimised properties of conductive polyaniline-polyvinyl alcohol ink painted on paper for ductile pressure sensor with reduced electrical drift

Polyaniline (PANI) powder in its emeraldine salt form was blended with various concentrations of polyvinyl alcohol (PVA) to create semiconducting inks with desired fluid properties. These inks were coated on cellulose paper, and their resistive responses were tested under different vacuum pressures. Enhanced conductivity and reduced creep behavior were achieved by incorporating an O–H bond between the H of PANI and O of PVA, which stabilizes the polymer structure. This bonding minimizes electrical drift, improving the reliability of the synthesized inks for applications such as designing flexible circuits and fabricating thermoelectric generators. The strain field developed under vacuum is accountable for the observed variation in electrical properties. Due to the increase in strain field, the polaron hopping barrier increases, and as a result, the effective conductivity decreases with a decrease in pressure. These ‘use-and-throw’ sensors are economical, adaptable, and environmentally friendly, ideal for various disposable electronics and sensing applications.

Design of Strain and Temperature Field Endoscopic Detection System for Hot-End Components of Aircraft

Design of Strain and Temperature Field Endoscopic Detection System for Hot-End Components of Aircraft

Exploring the frontier of 2D materials: Strain and electric field effects in MoS2/WS2 vdW heterostructures

Exploring the frontier of 2D materials: Strain and electric field effects in MoS2/WS2 vdW heterostructures

Investigation on properties of CuI/InSe heterojunction with Z–alignment for photocatalytic water splitting

The energetic, thermodynamic and mechanically stability as well as the electronic and optical properties of the monolayers CuI, InSe and the constructed CuI/InSe heterojunction have been investigated by first–principles calculations. The solar–to–hydrogen production efficiency of CuI/InSe heterojunction with or without applied electric field or biaxial strain has been predicted and elucidated in view of electronic structure systematically. The exciton binding energy and carrier mobility in CuI, InSe and CuI/InSe as well as the hydrogen and the oxygen evolution reaction have been analyzed. The predicted results show that the constructed 2D–CuI/InSe van der Waals heterojunction with Z–alignment is energetic, thermodynamic and mechanically stable. It enables the hydrogen production to take place on the CuI layer meanwhile oxygen is generated on the InSe layer during photocatalytic water splitting. The solar–to–hydrogen production efficiency of the constructed CuI/InSe1×1×1, CuI/InSe2×2×1 and CuI/InSe3×3×1 is predicted as 31.16%, 25.61% and 24.84% respectively. The exciton binding energy of CuI/InSe is lower than that of monolayers. A moderate negative applied electric field can promote the solar–to–hydrogen production efficiency of CuI/InSe while the positive electric field makes it decrease. Similarly, a moderate positive applied strain can also promote solar–to–hydrogen production efficiency of CuI/InSe significantly while the negative applied strain decreases the solar–to–hydrogen production efficiency.

Peak match sprinting speed during soccer matches: analysing the pre- and post-peak speed dynamics.

This study aimed to characterize match peak speeds, during a 20-second time window (10 seconds immediately before and after the match peak speed), in soccer matches. Twenty elite soccer players were monitored with global navigation satellite system (GNSS) devices during six soccer matches from the Brazilian first division. After identifying the peak speed, individual speeds within 10 seconds before and 10 seconds after were collected at each 0.1-second interval (10 Hz). Intra-individual speed differences were assessed at every second of the selected window using paired mean differences (with effect sizes and 95% confidence intervals). Match peak speeds ranged from 29.11 km/h to 31.64 km/h. Speeds registered 10 seconds before and 10 seconds after the match peak speed ranged from 5.11 km/h to 9.21 km/h and 6.90 km/h to 7.65 km/h, respectively. Speed increased moderately (effect size [95% confidence interval]: 0.68 [0.64, 0.73]) 4 seconds before the match peak speed and decreased moderately (effect size [95% confidence interval]: -0.73 [-0.78, -0.68]) 3 seconds after the maximal effort. Match peak speeds were achieved from flying starts, differing from the current sprint test procedures. Players needed to accelerate from speeds of approximately 10 km/h to reach their peak speed. After the match peak speed, players decelerated faster than they accelerated but without reaching a complete stop. Nevertheless, preparing players for intense decelerations should not be disregard. Players can benefit from field tests and training sessions that provide similarities to what occurs during competition, and accelerations should also be considered when referring to peak speeds.

Degeneration of the nucleus pulposus affects the internal volumetric strains and failure location of adjacent human metastatic vertebral bodies.

Intervertebral disc (IVD) degeneration is suspected to affect the distribution of stress and strain near the vertebral endplates and in the underlying bone. This scenario is worsened by the presence of metastatic lesions on the vertebrae (primarily thoracic vertebrae (60-80%)) which increase the risk of fracture. As such, this study aimed to evaluate the effect of IVD degeneration on the internal volumetric strains and failure modes of human metastatic vertebral bodies. Five human thoracic spinal segments including one vertebra with lytic metastases and one radiologically healthy vertebra (control) were in-situ tested in pure compression within a mCT scanner (isotropic voxel size = 39 mm). Each specimen was tested in the elastic regime before and after inducing mock IVD degeneration (enzymatic degeneration with collagenase); and at failure after IVD degeneration. The volumetric strain field was measured using a global Digital Volume Correlation approach (BoneDVC). After IVD degeneration, larger maximum (+187%, P = 0.002, 95% CI= [-4447, -1209]) and minimum (+174%, P = 0.002, 95% CI= [1679, 4258]) principal strains were observed in both metastatic and control vertebrae, with peak differences in correspondence of the IVD anulus fibrosus. IVD degeneration caused a transversal fracture pattern in the vertebrae with failure location onset in the middle portion of the vertebral body and in the cortical shell. In conclusion, IVD degeneration was found to be a key factor in determining the failure mode, suggesting the clinical relevance of including IVD level of degeneration to assess patients' risk of spinal instability. STATEMENT OF SIGNIFICANCE: Vertebrae can be affected by pathologies, like bone metastases, while intervertebral discs tend to degenerate during life. Generally, these structures and pathologies are studied separately. In this study, we explored the effects of artificial intervertebral disc degeneration on the mineralised tissues of the vertebrae with metastases. We observed that the induced intervertebral disc degeneration changes the mechanical behaviour of the vertebral trabecular bone. We believe that the findings of this study may influence the scientific community to develop new clinical tools for the prediction of the risk of fracture in vertebrae with spinal metastases, including the degeneration of the intervertebral discs as a parameter.

Concurrent Validity and Interunit Reliability of 25-Hz GNSS Units for Profiling Sprinting Performance.

Dennison, L, Duthie, GM, Ehrmann, F, and Psarakis, MA. Concurrent validity and interunit reliability of 25-Hz GNSS units for profiling sprinting performance. J Strength Cond Res 39(1): 107-114, 2025-Profiling sprint performance by assessing within-race velocity or time is crucial for understanding an athlete's capabilities and identifying areas for improvement. While traditional gold standard systems provide valid and reliable measurements, they are often costly, laboratory-based, or impractical for field-based settings. New Global Navigation Satellite System (GNSS) units (25 Hz) with higher sampling rates may address some of these limitations. The purpose of the project was to evaluate the concurrent validity and interunit reliability of 25-Hz GNSS units by examining their agreement with laser devices and timing gates for velocity measurements and sprint/interval times. Concurrent validity was assessed during a real track and field training session. Thirty subjects each completed 3 to 6 maximal 40-meter sprints, for a total of 106 sprints, while being assessed simultaneously through all systems. Interunit reliability was assessed by placing 3 GNSS units on a motor vehicle and completing 60 accelerations from 0 to 60 m. Low mean bias (<1%) and typical error less than <2% for all measurements demonstrate excellent agreement between GNSS and criterion devices. The units demonstrated good reliability for the 0-10 m interval time (intraclass correlation coefficient [ICC] = 0.86), excellent reliability for all remaining 10 m to 60 m intervals (ICC = 0.91-0.99), sprint times 0-60 m (ICC = 0.97), and maximal sprint velocity (ICC = 1.0). These GNSS units provide an efficient and feasible alternative to traditional measurement devices. For coaches, this technology offers a scalable method to concurrently assess the sprint performances of multiple athletes during training and competitions, enabling evidence-based decisions to guide athletic development.

The Meq Genes of Nigerian Marek’s Disease Virus (MDV) Field Isolates Contain Mutations Common to Both European and US High Virulence Strains

Background: Marek’s disease (MD) is a pathology affecting chickens caused by Marek’s disease virus (MDV), an acute transforming alphaherpesvirus of the genus Mardivirus. MD is characterized by paralysis, immune suppression, and the rapid formation of T-cell (primarily CD4+) lymphomas. Over the last 50 years, losses due to MDV infection have been controlled worldwide through vaccination; however, these live-attenuated vaccines are non-sterilizing and potentially contributed to the virulence evolution of MDV field strains. Mutations common to field strains that can overcome vaccine protection were identified in the C-terminal proline-rich repeats of the oncoprotein Meq (Marek’s EcoRI-Q-encoded protein). These mutations in meq have been found to be distinct to their region of origin, with high virulence strains obtained in Europe differing from those having evolved in the US. The present work reports on meq mutations identified in MDV field strains in Nigeria, arising at farms employing different vaccination practices. Materialsand Methods: DNA was isolated from FTA cards obtained at 12 farms affected by increased MD in the Plateau State, Nigeria. These sequences included partial whole genomes as well as targeted sequences of the meq oncogenes from these strains. Several of the meq genes were cloned for expression and their localization ability to interact with the chicken NF-IL3 protein, a putative Meq dimerization partner, were assessed. Results: Sequence analysis of the meq genes from these Nigerian field strains revealed an RB1B-like lineage co-circulating with a European Polen5-like lineage, as well as recombinants harboring a combination of these mutations. In a number of these isolates, Meq mutations accumulated in both N-terminal and C-terminal domains. Discussion: Our data, suggest a direct effect of the vaccine strategy on the selection of Meq mutations. Moreover, we posit the evolution of the next higher level of virulence MDVs, a very virulent plus plus pathotype (vv++).

Study of Adhesive Bonded Joints between Metallic Plates and Composite Laminates

Many researchers studied influences of various parameters on the failure behavior on the composites. One of the challenges in the analysis and design of bonded joints is the valuation of the stress and strain fields at the adhesive layer and adherents. The present investigation deals with the analysis of adhesively bonded dissimilar material single lap joints (SLJ) between mild steel and unidirectional carbon fibres reinforced polymer (CFRP) laminates. The primary objective of this study is to investigate the effects of various parameters, such as bonding strength, overlap length, adherend thickness, and adhesive thickness, on the failure load and failure mode of joints with dissimilar materials. Failure process, mode and strength of unidirectional composite to mild steel single lap adhesive bonded joints were investigated numerically by using finite element methods. Numerical methods based on finite element models can be very useful in describing the stress and strain responses for each load step. The SLJ specimens are done nonlinear analysis and predict the force -displacement and force- strains curves and conclusions regarding joint stiffness and strength are obtained for different cases of SLJ

4년제 대학생의 현장실습 경험이 진로결정 및 구직활동에 미치는 영향 분석

The purpose of this study is to analyze the effect of Field experiences of university students on career decision-making and job-seeking activities. To achieve this, data from the 3rd to 6th year of the Korean Education and Employment Panel II were utilized, and logistic regression analysis with propensity score matching was conducted to alleviate the problem of selection bias. The main findings are as follows. First, students who participated in field experiences showed a higher probability of engaging in career decision-making and job-seeking activities compared to those who did not participate. Second, participation in long-term field experiences exceeding 16 weeks was found to have no significant effect on career decision-making and job-seeking activities. In other words, there was no significant difference in career decision-making and job-seeking activities between students who participated in field experiences for more than 16 weeks and those who participated for 16 weeks or less. To effectively support career preparation and enhance employment capabilities for university students, policy improvements are needed. This includes both qualitative enhancements and appropriate training periods. Additionally, field training should be expanded quantitatively. Follow-up studies are also necessary to analyze the long-term effects of various majors and training periods.

Prediction of Mechanical Properties and Fracture Behavior of TC17 Linear Friction Welded Joint Based on Finite Element Simulation.

TC17 titanium alloy is widely used in the aviation industry for dual-performance blades, and linear friction welding (LFW) is a key technology for its manufacturing and repair. However, accurate evaluation of the mechanical properties of TC17-LFW joints and research on their joint fracture behavior are still not clear. Therefore, this paper used the finite element numerical simulation method (FEM) to investigate the mechanical behavior of the TC17-LFW joint with a complex micro-structure during the tensile processing, and predicted its mechanical properties and fracture behavior. The results indicate that the simulated elastic modulus of the joint is 108.5 GPa, the yield strength is 1023.2 MPa, the tensile strength is 1067.5 MPa, and the elongation is 1.98%. The deviations from measured results between simulated results are less than 2%. The stress and strain field studies during the processing show that the material located at the upper and lower edges of the joint in the WZ experiences stress and strain concentration, followed by the extending of the stress and strain concentration zone toward the center of the WZ. And finally, the strain concentration zone covered the entire WZ. The fracture behavior studies show that the material necking occurs in the TMAZ of TC17(α + β) and WZ, while cracks first appear in the WZ. Subsequently, joint cracks propagate along the TC17(α + β) side of the WZ until fracture occurs. There are obvious tearing edges formed by the partial tearing of the WZ structure in the simulated fracture surface, and there are fracture surfaces with different height differences at the center of the joint crack, indicating that the joint has mixed fracture characteristics.

Band Flattening and Strain Field Assists an Excellent Thermoelectric Performance of n‐type Bi2Se3 for Room to Mid‐Temperature Application

AbstractBismuth selenide, (Bi2Se3) is a typical n‐type V‐VI chalcogenide‐based thermoelectric (TE) material with high lattice thermal conductivity, which limits its TE performance. Single element doping is generally adopted to enhance the TE performance, since it is not affect significantly. Herein, it is revealed that the impact of the co‐doping strategy boost the TE performance of Bi2Se3 through tuning the band structure and phonon transport properties. The synergy of isovalent Ga (gallium) and aliovalent Ge (germanium) co‐doping produces a noteworthy improvement in carrier tuning from −1.1 × 1018 to −3.56 × 1018 cm−3. Bi1.95Ga0.05Ge0.033Se3 sample reached the enhanced power factor of 1403 µWm−1K−2 obtained at 303 K. The reduced low lattice thermal conductivity of 0.24 Wm−1K−1 is occurred by the multi‐scale phonon scattering mechanisms through the dissemination of strain field raised from various defects. The combined strategy of flat band structure and low lattice thermal conductivity significantly optimized the thermoelectric zT of 0.7 is achieved at 513 K and the highest zTaverage of 0.68 is obtained. The maximum zT values leads to attain a theoretical efficiency of 5.9% in the temperature range between 333–573 K. This work shows a practical approach to improve the zT of n‐type Bi2Se3 via co‐doping.

Inheritance mode and metabolic mechanism of bromopropylate resistance in a field strain of Panonychus citri (Acari: Tetranychidae)

ABSTRACT Panonychus citri is a serious pest of citrus orchards all around the world. In this study, biochemical and resistance inheritance mechanisms of bromopropylate were evaluated on a field population of P. citri. The resistance inheritance of bromopropylate in P. citri has been studied by crossing resistant (As) and susceptible (So) populations, derived from collected populations in northern cities of Iran. The resistance ratios were estimated at 11.45, 3.45, 3.49, 3.72, and 6.16- folds in As, F1, F´1, F2, and F´2 in comparison to the So, respectively. The results of the response showed that resistance was inherited as a bromopropylate incomplete recessive inheritance (D = −0.01 and −0.02) that was detected as polygenic autosomal. The DEM, TPP, and PBO synergism assays in the As population reached 2.27, 2.24, and 1.66- folds, respectively. The in vivo enzyme assays suggested minor involvement of cytochrome P450 monooxygenases, esterases, and GSTs in the P. citri population resistance to bromopropylate, with the highest ratio related to esterases.