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The work presents a solution to the bending problem of an infinite piecewise homogeneous isotropic plate with an elastic circular washer and a radial through straight crack. It was assumed that under the action of an external loads at infinity, the edges of the crack are smoothly contacted on area of constant width (strip contact) on the upper base of the plate. The solution of the problem is built using the methods of the theory of functions of a complex variable and complex potentials and is reduced to a system of singular integral equations, which is numerically solved using the method of mechanical quadrature A numerical analysis of the problem is conducted and graphic dependencies of contact force, coefficients of intensity of moments and forces at various parameters of the problem were constructed. [ABSTRACT FROM AUTHOR]

Monolithic zirconia (MZ) crowns are widely utilized in dental restorations, particularly for substantial tooth structure loss. Inspection, tactile, and radiographic examinations can be time-consuming and error-prone, which may delay diagnosis. Consequently, an objective, automatic, and reliable process is required for identifying dental crown defects. This study aimed to explore the potential of transforming acoustic emission (AE) signals to continuous wavelet transform (CWT), combined with Conventional Neural Network (CNN) to assist in crack detection. A new CNN image segmentation model, based on multi-class semantic segmentation using Inception-ResNet-v2, was developed. Real-time detection of AE signals under loads, which induce cracking, provided significant insights into crack formation in MZ crowns. Pencil lead breaking (PLB) was used to simulate crack propagation. The CWT and CNN models were used to automate the crack classification process. The Inception-ResNet-v2 architecture with transfer learning categorized the cracks in MZ crowns into five groups: labial, palatal, incisal, left, and right. After 2000 epochs, with a learning rate of 0.0001, the model achieved an accuracy of 99.4667%, demonstrating that deep learning significantly improved the localization of cracks in MZ crowns. This development can potentially aid dentists in clinical decision-making by facilitating the early detection and prevention of crack failures. [ABSTRACT FROM AUTHOR]

Diagnosis of compound faults plays a significant role in evaluating the health status of a gearbox. The difficulty of compound fault diagnosis is due to the entanglement of fault symptoms. In this work, diagnosis of single and compound uniform wear and tooth root crack via gear condition indicators have been studied analytically. A three-dimensional dynamic model that can include several design parameters and working conditions has been employed to model the dynamic of compound faults for the first time. The effect of fault severity, noise, working conditions, and design parameters on the diagnosis efficiency have been investigated. The qualitative and quantitative assessment of fault diagnosis has been accomplished via t-SNE and Generalized Discriminative Value (GDV) measures, respectively. The results show that the gear condition indicators are more suitable to assess the general health state of the gearbox. However, their ability to detect the type of fault and decouple compound faults are limited. Furthermore, design parameters of the gear transmission system, such as helix angle and gear width, can highly affect the fault diagnosis efficiency. [ABSTRACT FROM AUTHOR]

Copyright of Automotive Engineer (1674-6546) is the property of Auto Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The main failures that could deteriorate the reliable operation of solid rocket motors (SRMs) and lead to catastrophic events are related to bore cracks and delamination. Current SRMs' predictive assessment and damage identification practices include time-consuming and cost-demanding destructive inspection techniques. By considering state-of-the-art optical strain sensors based on fiber Bragg gratings, a theoretical study on the use of such sensors embedded in the circumference of the composite propellant grain for damage detection is presented. Deep neural networks were considered for the accurate prediction of the presence and extent of the defects, trained using synthetic datasets derived through finite element analysis method. The evaluation of this combined approach proved highly efficient in discriminating between the healthy and the damaged condition, with an accuracy higher than 98%, and in predicting the extent of the defect with an error of 2.3 mm for the bore crack depth and 1.6° for the delamination angle (for a typical ~406 mm diameter grain) in the worst case of coexistent defects. This work suggests the basis for complete diagnosis of solid rocket motors by overcoming certain integration and performance limitations of currently employed dual bond stress and temperature sensors via the more scalable, safe, sensitive, and robust solution of fiber optic strain sensors. [ABSTRACT FROM AUTHOR]

Cracks, common indicators of deterioration in bridge frameworks, frequently stem from wear and rust, leading to increased local flexibility and changes in the structure's dynamic behavior. This study examines how these cracks affect the dynamics of footbridges when subjected to loads generated by walking individuals. The pedestrian is modeled as a linear oscillator, while the cracked bridge is represented by a simply supported beam following Euler–Bernoulli's theory. The use of the Dirac delta function allows for the precise representation of the localized stiffness reduction at the crack location, facilitating the calculation of analytical expressions for the beam's vibration modes. The research suggests that the presence of cracks minimally affects the bridge's mid-span displacement. However, with a limited depth of cracks, the appearance of cracks notably amplifies the mid-span acceleration amplitude of the bridge, leading to a pronounced concentration of energy at the third natural frequency of the bridge in the acceleration spectrum. As the depth and number of cracks increase, the acceleration amplitude continues to decrease, but the corresponding spectrum remains almost unchanged. The study's outcomes enhance the comprehension of how cracks affect the performance of bridge structures when subjected to loads from pedestrians, offering insights for the monitoring and evaluation of the condition of cracked footbridges. [ABSTRACT FROM AUTHOR]

The ground cracks resulting from coal mining activities induce alterations in the physical and chemical characteristics of soil. However, limited knowledge exists regarding the impact of subsidence caused by coal mining on the distribution of potentially toxic elements (PTEs) fractions in farmland soil. In this study, we collected 19 soil profiles at varying depths from the soil surface and at horizontal distances of 0, 1, 2, and 5 m from the vertical crack. Using BCR extraction fractionation, we determined the geochemical fractions and total concentrations of Chromium (Cr), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd) and lead (Pb) to investigate their ecological risk, spatial fraction distribution, and main influencing factors. Results showed that the E r i values of Cd appearing in 68.7% of the samples were higher than 40 and less than 80, presented a moderate ecological risk. Chromium (Cr), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), and lead (Pb) were mainly bound to residual fractions (> 60%) with lower mobility and Cd was dominated by F1 (acid-soluble fractions, 50%) and F2 (reducible fractions, 29%) in surface soil (0–20 cm). The geochemical fractionation revealed that the mobile fractions (F1—acid-soluble and F2—reducible) of PTEs were primarily located near the crack, influenced by available potassium. In contrast, the less mobile fractions (F3—oxidizable and F4—residual) exhibited higher concentrations at distances of 2 and 5 m from the crack, except for arsenic, influenced by the presence of clay particles and available phosphorus. [ABSTRACT FROM AUTHOR]

This research delves into the performance of dowels in reinforced concrete joints, highlighting the crucial role of subgrade reaction in providing firm support for dowel bars. The experimental analysis conducted on jointed specimens loaded below their dowel capacity revealed permanent deformations. The examination discerned a gradual extension of cracks emanating from the joint interface, attributing their initiation to bond deterioration under cyclic loading conditions. This research encompasses diverse variables, including dowel arrangements, bar sizes, types, confinement levels, bond conditions, and section size, offering a comprehensive exploration of factors influencing this different joint behavior. [ABSTRACT FROM AUTHOR]

Copyright of Metal Working (1674-165X) is the property of Metal Working Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

High-strength advanced steel and welded structure are key for service safety and life. Static and dynamic compressive mechanical behavior of high-strength 22SiMn2TiB armor steel and welded structure is investigated, which are carried out by using universal testing machine and split Hopkinson pressure bar. The studied materials are obtained from high-strength steel matrix, welded seam and mix of them with interface, respectively. The strain rate in experiments covers the range of 0.001/s to 6000/s. The mechanical data involve stress-strain relations and strain rate dependencies of mechanical properties. The cracking behavior as well as the corresponding microstructures are characterized at different length scales from millimeter to micron scale by optical microscope and scanning electron microscope. The results show that static (0.001/s) and dynamic (5000/s) yield strengths are 1600 MPa and 2400 MPa for high-strength steel matrix, 400 MPa and 1200 MPa for welded seam, 950 MPa and 1600 MPa for mix of them with interface, respectively. Under dynamic loading, shearing occurs and results in the fracture. Along the interface of steel matrix and welded seam, cracks are firstly initiated and propagated. The relations of mechanical properties and fracture features are analyzed, where strain rate effect is mentioned. This work will guide the design and application for engineering structure.

Many engineering disasters are related to water infiltration in cracks. Understanding the water infiltration in multi-layered sandstone cracks is crucial for monitoring and preventing water-related disasters in coal mines. In this study, we utilized the electrical resistivity tomography (ERT) technique to conduct a water infiltration monitoring experiment on the 2d-strata-model with cracks. The electrical resistivity ratio profiles with respect to the background unveiled the existence of three cracks. Model photography demonstrates two cracks of those cracks. The infiltration cracks exhibit distinct shape of a stripe or island chain electrical change ratio anomaly in the resistivity ratio profiles. Electrical resistivity change ratio is associated with the infiltration within the cracks. As the infiltration progresses, the resistivity change ratios relative to the background gradually decreases. This is evident in the reduction in ratios in the original stripe or island chain areas in the electrical resistivity ratio profiles. The diminished range expands, manifesting as an increase in the area of the original stripe or island chain. The infiltration patterns of the cracks can be categorized into three types: a stripe pattern, island chain and stripe pattern, and island chain pattern. The preferential flow paths along the crack are related to both the infiltration time and the volume of infiltration. In the early stages, there are clear preferential flow paths along cracks. However, as infiltration time and volume increase, these preferential flow paths along the cracks become less pronounced and may even disappear. The findings prove that ERT is suitable for monitoring water infiltration along the cracks in multi-layered sandstone in the early infiltration stage. Experiment results monitoring water infiltration cracks on the 2D-model show that the ERT and 2D-model are suitable for studying water infiltration along the cracks. This research can provide valuable reference for preventing engineering disaster.

For decades, resistance spot welding (RSW) between aluminum and copper has encountered difficulties; however, it remains essential for modern applications. Additionally, crack propagation and the stress intensity factor (SIF) of dissimilar RSW have not been extensively investigated. The welding parameters used for Al-Al joints were as follows: welding current, time, and electrode force were set at 14,000 Amps, 0.8 seconds, and 7,000 N, respectively. Conversely, for Al-Cu joints, 14,000 Amps, 1 second, and 8,800 N were determined. The similar joints exhibited an average weld nugget size of 6 mm, whereas the dissimilar joints had a nugget size of 5.2 mm. The tensile shear force was 690 N and 780 N for dissimilar and similar joints, respectively. Accordingly, the fatigue load, as a percentage of the tensile force, was utilized at 414 N and 468 N for Al-Cu and Al-Al, respectively. Finite Element Analysis (FEA) was employed to determine the SIF. The initial crack length was determined to be 0.1 mm. The numerical solution was then compared with theoretical solutions for the opening SIF-KI, such as the equations proposed by Pook and Zhang. The FEA results showed higher values of SIF compared to those from theoretical solutions. Additionally, crack propagation was investigated for both dissimilar and similar joints at a determined failure load. Cracks tended to develop close to the heat-affected zone (HAZ) around the weld nugget diameter (dn). SIF and crack path have been verified.

At present, cracking is the main form of damage to ultra-high performance concrete (UHPC), and increasing flexural toughness is the primary technical approach to addressing this issue. Currently, fiber, polymer, or nanomaterial modification is commonly used to improve UHPC toughness. Emulsified asphalt has also demonstrated the potential to toughen and resist cracking. To investigate the toughening effect of emulsified asphalt in cementitious materials, this study employed a method in which emulsified asphalt and water are added simultaneously during wet mixing to prepare UHPC specimens. The effects of different types and dosages of emulsified asphalt on the workability, mechanical strength, and flexural toughness of UHPC were investigated through extensibility tests, flexural toughness tests, compressive strength tests, flexural strength tests, and tensile strength tests. The results showed that the workability of UHPC mixes with two types of emulsified asphalt gradually decreased as the emulsified asphalt dosage increased. When the dosage of either type of emulsified asphalt exceeded 3%, the extension did not meet the specification requirements. Furthermore, as the dosage of the two types of emulsified asphalt increased, the mechanical strength of the UHPC slightly decreased. Compared with the same dosage of cationic emulsified asphalt, anionic emulsified asphalt had a smaller impact on the mechanical strength of UHPC because anionic emulsified asphalt and cement hydration products both carried the same charge, causing them to repel each other. This mutual repulsion reduced the influence of emulsified asphalt on the cement hydration reaction process, which was conducive to the generation of cement hydration products. Consequently, the negative impact on the formation of UHPC strength was lessened, and the uniformity of the steel fiber distribution within the UHPC was ensured. In terms of flexural toughness, both types of emulsified asphalt enhanced the flexural toughness of the UHPC, with anionic emulsified asphalt providing better results than cationic emulsified asphalt. Compared with cationic emulsified asphalt, anionic emulsified asphalt resulted in better workability and mechanical strength in the UHPC, and its toughening effect was more significant. Considering both mechanical properties and overall performance, the use of anionic emulsified asphalt in UHPC is recommended, with an optimal dosage of 3%. The microstructure of UHPC specimens without emulsified asphalt and those mixed with 3% anionic emulsified asphalt was observed using a scanning electron microscope. The observations revealed that emulsified asphalt could fill the original microcracks in UHPC, improve the internal structure of the matrix, increase the effective contact area between steel fibers and the matrix to a certain extent, and enhance the toughening effect of steel fibers. Additionally, the viscoelastic properties of emulsified asphalt increased the energy required for crack propagation, effectively reducing the generation and development of microcracks and serving as a buffer for the destabilization damage of hydration products.

The incorporation of nanofillers makes it possible to permanently modify the properties of the adhesive. Nanoparticles with structures of less than 100 nanometers can be incorporated in suitable amounts up to 30% by volume into liquid adhesives without significantly changing the rheology. Fine and nanometric particles of Si02 are now increasingly incorporated into aqueous adhesive dispersions. The objective of this study is to analyze numerically by the three-dimensional finite element method, the intensity and distribution of von Mises, shear and peeling stresses in a nanostructured adhesive joint which ensures the assembly of two plates in Aluminum alloy 2024-T3. This adhesive is epoxy DER 331 in nature, filled with spherical silica nanoparticles (SiO2) of same size, the content of which varies from 0% to 30%. These silica nanoparticles are injected into the adhesive in the liquid state in a homogeneous way in order to see their effects on the mechanical behavior of the epoxy-nanosilica composite. The stresses are also evaluated according to the length of the adhesive lap and its thickness when crossing the crack front. The results obtained numerically by the finite element method show that the addition of nanoparticles in the epoxy matrix with ductile behavior contributes to the improvement of the mechanical properties of the epoxy-nanosilica composite, by increasing its mechanical resistance to the propagation of cracks. The presence of nanoparticles makes it possible to slow down the propagation of the crack. [ABSTRACT FROM AUTHOR]

Abstract Background In recent years, overdoses involving illicit cocaine, methamphetamine, and other stimulants have increased in the U.S. The unintentional consumption of stimulants containing illicit fentanyl is a major risk factor for overdoses, particularly in Massachusetts and Rhode Island. Understanding the drug use patterns and strategies used by people who use stimulants (PWUS) to prevent overdose is necessary to identify risk and protective factors for stimulant and opioid-involved overdoses. Mixed-methods research with people who distribute drugs (PWDD) can also provide critical information into the mechanisms through which fentanyl may enter the stimulant supply, and the testing of drug samples can further triangulate PWUS and PWDD perspectives regarding the potency and adulteration of the drug supply. These epidemiological methods can inform collaborative intervention development efforts with community leaders to identify feasible, acceptable, and scalable strategies to prevent fatal and non-fatal overdoses in high-risk communities. Methods Our overall objective is to reduce stimulant and opioid-involved overdoses in regions disproportionately affected by the overdose epidemic. To meet this long-term objective, we employ a multi-pronged approach to identify risk and protective factors for unintentional stimulant and opioid-involved overdoses among PWUS and use these findings to develop a package of locally tailored intervention strategies that can be swiftly implemented to prevent overdoses. Specifically, this study aims to [1] Carry out mixed-methods research with incarcerated and non-incarcerated people who use or distribute illicit stimulants to identify risk and protective factors for stimulant and opioid-involved overdoses; [2] Conduct drug checking to examine the presence and relative quantity of fentanyl and other adulterants in the stimulant supply; and [3] Convene a series of working groups with community stakeholders involved in primary and secondary overdose prevention in Massachusetts and Rhode Island to contextualize our mixed-methods findings and identify multilevel intervention strategies to prevent stimulant-involved overdoses. Discussion Completion of this study will yield a rich understanding of the social epidemiology of stimulant and opioid-involved overdoses in addition to community-derived intervention strategies that can be readily implemented and scaled to prevent such overdoses in two states disproportionately impacted by the opioid and overdose crises: Massachusetts and Rhode Island.

Abstract When applying deep learning and image processing techniques for bridge crack detection, the obtained images in real-world scenarios have severe image degradation problem. This study focuses on restoring low-illumination bridge crack images corrupted by noise to improve the accuracy of subsequent crack detection and semantic segmentation. The proposed algorithm consists of a deep CNN denoiser and a normalized flow-based brightness enhancement module. By taking the noise spectrum as an input, the deep CNN denoiser restores image at a broad range of noise levels. The normalized flow module, employs a conditional encoder and a reversible network to map the distribution of normally exposed images to a Gaussian distribution, effectively improving the image brightness. Extensive experiments have demonstrated the approach can usefully recover low-illumination images corrupted by noise compared to the state-of-the-art methods. Furthermore, the algorithm presented in this study can also be applied to other image quality restoration with high generalization and robust abilities. And the semantic segmentation accuracy of the restored image is significantly improved.

Road crack detection is critical to road infrastructure maintenance, requiring sophisticated and accurate approaches. This research explores the utilization of a combination of Wavelet and Convolutional Neural Network (CNN) methods to improve efficiency and accuracy in detecting cracks in road images. The wavelet method was chosen for its capability to capture information at different scales, enabling improved feature extraction. Meanwhile, CNN was utilized to comprehend the spatial context and tackle image complexity. The research involves several stages, including data collection, pre-processing, decomposition using the Wavelet method, forming of the CNN architecture model, training, testing, and evaluating the result. The tested images involve three main types of cracks: alligator, linear, and images without cracks. The testing results show that the developed model is capable of classifying cracks with an F1-score of 0.96, recall of 0.96, and precision of 0.96. In real-time detection of road cracks, the testing obtained an F1-score of 0.84, recall of 0.92, and precision of 0.77. This research contributes to the advancement of road crack detection technology by leveraging the capabilities of Wavelet and CNN, enhancing the accuracy and efficiency of crack detection in road maintenance.

In this paper, an approach is developed to account for the effect of discrete cracks on the response of reinforced concrete building frames under a column failure scenario. The approach implies the introduction of traditional finite element models of discrete ties that take into account the relationship between moments and rotations, considering the specifics of the performance of materials, sections, and structures under conditions of redistribution of forces as a result of initial local failure in the structural system of a building. Validation of the proposed approach is performed on the experimental data. Also, it is compared with the modeling results of the existing approaches. The effect of discrete cracking on the deformed state of reinforced concrete building frames under the scenario of column failure is established. The discrete cracks practically did not affect the values of axial forces in the elements. However, for bending moments within the proposed method, a decrease was observed in comparison with the traditional approach. The analysis of the diagrams shows that for reinforced concrete frames with 3 and 5 stories, there is an excess of tensile axial forces in the beam over the values according to the traditional calculation method.

Objective Surface displacement and crack development are the most intuitive manifestations of landslide deformation and evolution. Therefore, revealing the characteristics and evolution stages of landslide deformation and failure through displacement monitoring and surface crack survey is highly practical. Methods In this study, the Baishuihe landslide in the Three Gorges Reservoir Area is selected as the research case, and monitoring data from 2003-2016 for this landslide are systematically collected and analyzed, taking monitoring points ZG93 and ZG118 as example. First, the fractal parameter Hurst index R/S analysis is carried out for the displacement data. Second, the multiple fractal dimensions of the displacement of the two monitoring points are calculated every year. Finally, the theory of stage matching of landslide cracks is introduced, and the crack fractal dimension of the Baishuihe landslide is determinated. Results The results show that there is a certain positive correlation between the landslide displacement sequences, and the fractal dimension H index of the two monitoring points is greater than 0.5. The evolution process of the Baishuihe landslide can be divided into a steady deformation state (from June 2003 to June 2007), an accelerated deformation state (from June 2007 to December 2009), and a steady deformation state (from December 2009 to December 2015). According to the matching law of crack stages, the development of the landslide is the initial deformation stage. Conclusion The research results have a certain guiding significance for revealing the evolutionary state of reservoir landslides.

Recent results in mathematical modeling predicting crack behavior under various load conditions in human bones as anisotropic elastic composite materials are presented in this survey. New and interesting challenges in theoretical models of fracture were proposed and had significant importance for fracture mechanics. Our goal is to present an overview of the use and limitations of existing relevant theories. The present study aims to introduce mathematical models to researchers unfamiliar with the concepts, to improve and provide new insights into bone fracture mechanics.

A melting failure of W monoblock components of the upper divertor outer target in EAST occurred during the plasma campaigns in 2019. The failure characters and microstructure evolution of the failed W monoblock have been well investigated on one string (W436 string). Near the strike point region where heat flux density is highest, macroscopic cracks and severe surface damage such as dimensional change, melting and solidification are visible in several W monoblocks. At the same time, debonding, melting and migration of Cu/CuCrZr cooling tube components introduced fatal damage to the structure and function. The heat-induced microstructure evolution in the rest part has been examined via hardness tests and metallography. From the heat flux surface to the cooling tube, hardness increased gradually and the recrystallized grains could be found in the region with the highest temperature, while recrystallization grains also appear in some W monoblocks near the cooling tube area. The detailed microstructure has been investigated by metallography and EBSD. Such cases in EAST provide experiences on the extreme condition of accidental loss of coolant or higher discharge power in future devices.

IntroductionOn the field and in the paddy milling factory dryer losses have always been challenging issues in the rice industry. Different forms of losses in brown rice may occur depending on the field and factory conditions. To reduce the losses, proper management during pre-harvest, harvesting, and post-harvest operations is essential. In this study, different on-field drying and tempering methods were investigated to detect different forms of brown rice losses.Materials and MethodsThe present study was conducted on the most common Hashemi paddy variety during the 2019-2020 season in Talesh, Rezvanshahr, and Masal cities in the Guilan province, Iran with 0.2 hectares and 5 paddy milling factory dryers. On the fields, the method and date of tillage, irrigation, and transplanting used in all experimental units were the same. Moreover, the same amount of fertilizer and similar spraying methods were used across all experiments. For the pre-drying process on the fields, the following three pre-drying methods were applied on the harvest day: A1) The paddies were spread on the cut stems for insolating, A2) The paddies were stacked and stored after being placed on the cut stems for 5h, and A3) The paddies were covered with plastic wrap and stored after 5h of insolating. The first method (A1) is the most common in the area and was chosen as the control treatment. For the second step of the process, the time interval between the on-field pre-drying and threshing was considered: B1) 14 to 19h post-harvest; B2) 20 to 24h post-harvest, and B3) 25 to 29h post-harvest. Afterward, methods A1 to A3 were combined with methods B1 to B3 and feed into an axial flow-thresher at 10 kg min-1, 550 rpm PTO, and two levels of moisture content at 19 and 26 percent (% w.b). The third process was two-stage or three-stage tempering for 10 or 15 hours resulting in four levels (C1 to C4) and was done in the conventional batch type dryer under temperatures of 40 and 50 ˚C and airspeeds of 0.5 and 0.8 m s-1 in paddy milling factories. At the end of each process, a 100g sample was oven-dried for 48h and a microscope achromatic objective 40x was used to detect incomplete horizontal or vertical cracks, tortoise pattern cracks, and immature and chalky grains. The equilibrium moisture content was determined to be 7.3 percent. Losses properties were analyzed using a completely randomized factorial design with a randomized block followed by Tukey's HSD test at the 5% probability and comparisons among the three replications were made.Results and DiscussionResults demonstrated that the stack and plastic drying methods significantly increased the percentage of losses. In the plastic drying method, the percentage of chalky grains and tortoise pattern cracks was higher than other forms of loss. In the first process, irrespective of the pre-drying method, the losses were reduced at a lower level of moisture content. At the end of the first stage, losses in the spreading method were significantly lower at 19% moisture content. Threshing the plastic-wrapped paddies after 14 to 19 hours at 19% moisture content resulted in the maximum threshing loss of 8.446% and over half of the grains were chalky or had tortoise pattern cracks. The threshing loss was halved (4.443%) for paddies threshed 25 to 29h after spreading at a moisture content of 26%. The mean of losses in the second step of the process were 7.229, 5.585, and 5.156% for the time interval between the on-field pre-drying and threshing of 14 to 19h, 20 to 24h, and 25 to 29h, respectively. In the last step of the process in paddy milling factory dryers, there was no significant difference in the minimum percent of losses between 10 and 15 hours of three-stage tempering at 40 °C and with 0.5 m s-1 airspeed. Furthermore, maximum total losses with the most incomplete horizontal and vertical cracks occurred in the two-stage 10h tempering at 50 °C and with 0.5 and 0.8 m s-1 airspeed.ConclusionFood security has always been a critical matter in developing countries. Furthermore, identifying the source of losses in the fields and the factories is one way to reduce losses and achieve food security. Stacking or wrapping the paddies in plastic after pre-drying on the fields for 5h is not recommended in terms of its effect on increasing the percentage of brown rice losses. Additionally, due to the importance of factory dryer scheduling in the management of the losses, it is recommended to use a three-stage 10h tempering at 40 °C and with 0.5 m s-1 airspeed.

This paper studies the instability of a non-ideal pipe system conveying fluid. Unlike ideal modeling, three types of possible non-ideal factors have been considered in the present analysis. The pipe has a crack and is subjected to boundary relaxation, and the fluid in the pipe is viscous. It is an interesting instability problem of a fluid-structure system with multiple forms of imperfections. It gains motivation from our previous study and aims at further essential results for comprehensively understanding the nature of such a problem. In order to incorporate multiple imperfections, a new data-driven approach is developed to model the non-ideal pipe-fluid system. Then the influences of the support stiffness, fluid–solid mass ratio, crack, and fluid viscosity on the pipe instability are systematically discussed. Results show that the pipe exhibits flutter-divergence conversion at low mass ratios and flutter-mode transition at high mass ratios. Due to the two types of instability transitions, the critical flow speed could experience multiple sudden jumps as the support stiffness changes. With the imperfections of crack and viscous flow, the pipe's instability behavior tends to be more complicated, but the inducing mechanisms for the sudden changes are straightforward. They are instability-type conversion, instability-mode transition, and laminar-turbulent flow transition. [ABSTRACT FROM AUTHOR]

The paper investigates a problem concerning the equilibrium of a solid body containing a thin rigid inclusion and a crack. It is assumed that the body is hyperelastic, therefore, it is described within the framework of finite strain theory. One of the peculiarities of this problem is a global injectivity constraint, which prevents the body, the crack faces and the inclusion from both mutual and self penetration. First, the paper deals with the differential formulation of the problem. Next, we consider energy minimization, showing that the latter provides the weak formulation of the former. Finally, the existence of the weak solution is demonstrated through the use of the variational technique. This article is part of the theme issue 'Non-smooth variational problems with applications in mechanics'. [ABSTRACT FROM AUTHOR]

The cracking of recycled aggregate concrete (RAC) is well known to promotes the chloride diffusion, accelerates the corrosion of reinforcement embedded in RAC. To reveal the mechanism of chloride diffusion in RAC under cracking, a multiphase mesoscopic model for chloride diffusion in RAC was proposed. It should be noted that RAC is regarded as eight-phase composite materials consisting of coarse aggregate, reinforcement, new and old mortar, new and old interface transition zones (ITZ), cracks, and damage zones. The effects of the width and depth of cracks and damage zones on chloride diffusion behavior in RAC after cracking were further investigated. The numerical simulation results show that the damage zones accelerate the chloride diffusion and exacerbates the accumulation effect of chloride at the crack tip. Compared to the crack depth, the crack width of RAC has a small effect on chloride diffusion behavior, especially, the crack width is less than 50 μm. More importantly, the chloride diffusion streamline generated by numerical simulation reveals the mechanism of cracks promoting chloride diffusion. The research in this paper provides new insights into the durability design of RAC by revealing the diffusion behavior of chloride ions in RAC. [ABSTRACT FROM AUTHOR]

To solve the problem that the existing planetary gear train fault diagnosis methods have, namely their low diagnostic accuracy under low signal-to-noise ratio (SNR), a fault diagnosis method based on a double channel-deep residual shrinkage network (DC-DRSN) is proposed. The short-time Fourier transform (STFT) is used to convert the original vibration signal into a two-dimensional time-frequency graph, which effectively enhances the ability to express information. A DC-DRSN model is constructed, and the optimal number of residual shrinkage modules is determined by combining the diagnostic characteristics with different noises, which effectively improves the accuracy and anti-noise ability of fault diagnosis. The results of bearing and planetary gear train crack fault diagnosis show that the diagnosis method based on DC-DRSN has higher diagnostic accuracy while realizing fault diagnosis, which is better than other deep learning diagnosis methods. At the same time, the method can adapt to fault diagnosis in different noise environments, and has good expression ability and generalization ability. [ABSTRACT FROM AUTHOR]

The checkerboard constitutes the best pattern for full‐field strain measurement because it maximizes image gradient. In the experimental mechanics community, employing this pattern is currently strongly limited because depositing it on the surface of specimens raises practical difficulties. A recent study shows, however, that it is technically possible by using a laser engraver. The present paper aims to push this solution forward by printing a checkerboard pattern on a thin polymeric film and then gluing the resulting laser‐engraved film on the specimen surface. The underlying idea is to separate the manufacturing process of this optical strain gauge on the one hand and its use on the other hand to help spread this strain measuring tool in the experimental mechanics community. The polymeric film employed here is the same as that used in the manufacturing process of classic electrical gauges, so one can rely on the know‐how of classic strain gauge bonding to glue this optical strain gauge on the specimen surface. The main difference between the proposed tool and classic electrical gauges is that the strain field beneath the polymeric support is measured instead of localized strain values. The paper is a proof of concept for this strain field measuring tool. The manufacturing and bonding processes are described in the paper. The localized spectrum analysis, a spectral technique developed for processing images of periodic patterns, is used to retrieve the strain fields from checkerboard images. Through two complementary examples, we show the ability of this new type of strain gauge to detect and quantify local details in the strain field beneath. A simplified 1D model is also proposed to assess the minimum width of the strain peak that can reliably be measured with this technique. [ABSTRACT FROM AUTHOR]

In recent years, various monitoring methods for concrete structures have been widely researched and applied. However, there are still many research gaps found in related research due to the absence of comprehensive research that maps this research trend. This research presents a comprehensive bibliometric and scientometric analysis regarding "Monitoring Cracks in Concrete Structures" by Scopus over the last decade (2013-2023) with the help of VOS viewer software. From the results of the analysis, it was found that the research trend was increasing with research developments led by China and the USA. The results of the network visualization analysis also show 7 clusters or hotspots for research development, one of which is the concrete damage detection method. In the future, collaboration and integration of monitoring systems based on IoT, deep learning, and CNN can be further developed, so that the data produced is more real-time and accurate. [ABSTRACT FROM AUTHOR]

This research work aims to investigate experimentally the torsional behaviour of self-compacting reinforced concrete hollow beams with recycled concrete aggregate. Twelve beams were cast and tested. The beams have the same dimensions, and the variables that were investigated include, recycled aggregate content, longitudinal reinforcement, and transverse reinforcement. The test results revealed that for all beams no significant difference in behaviour was identified when comparing beams with recycled aggregate with those with normal aggregate. All the beams exhibited almost similar linear torque-rotation behaviour, but beams with RCA showed lower cracking torque and the twist angle depended on the replacement ratio of RCA. Beams without any reinforcement failed suddenly and separated into two parts, while beams with longitudinal bars showed brittle torsional failure, beams with both longitudinal and transverse reinforcement showed an increasing post-cracking behaviour with the formation of an increase in the number of helical and diagonal cracks. [ABSTRACT FROM AUTHOR]

The stabilization/solidification method can improve the engineering properties and reduce the environmental risks of heavy metal-contaminated expansive soil. However, the solidification effects deteriorate for soils experiencing wetting–drying (W–D) cycles. For this objective, the expansion/shrinkage, cracking, and leaching behaviors, as well as the corresponding internal relations, of lime-solidified lead-contaminated expansive soil were investigated. The results showed that during the W–D process, the volumetric strain increased, particularly along the radial direction. The cracks gradually developed and increased in length, width, and surface-crack ratio. Contaminant leaching and mobility increased, increasing environmental risk. In addition, a higher Pb(II) concentration in the solidified soil exhibited a more notable expansion potential release, crack development, and leaching capacity. X-ray diffraction and scanning electron microscopy results revealed the redistribution of soil particles and pores rather than chemical changes in mineral components during the deterioration process, and increasing the lead concentration accelerated the deterioration of W–D cycles. Finally, based on the grey correlation analysis, deterioration effects in leaching behaviors were controlled by expansion/shrinkage exponential release for solidified soil experiencing lower W–D cycles and higher Pb(II) concentrations, whereas leaching behaviors were controlled by crack behavior for solidified soil experiencing higher W–D cycles and lower Pb(II) concentrations. [ABSTRACT FROM AUTHOR]

Highlights Clamped single edge notched tensile (SENT) specimens are widely used in fracture toughness test and fatigue crack growth experiment of structural materials. However, the existing fracture parameters of clamped SENT specimens are all based on isotropic conditions, which limits the application of anisotropic materials. In this study, a systematic finite element analysis of orthotropic clamped SENT specimens was carried out to determine the stress intensity factor (K) and compliance (C). A wide range of orthotropic and geometric parameters, including crack length over width ratio (a/W), daylight to width ratio (H/W), and material parameters λ and ρ, were considered. The coupling effects of material parameters and geometrical dimensions on fracture properties were then investigated. Results showed that the K and C increase with the increase of a/W and H/W, and decrease with the increase of λ and ρ. The value of C is more sensitive to changes of orthotropic and geometric parameters than the K. Moreover, the accurate solutions for normalized K, C and compliance‐based crack length prediction were developed. Applications of the proposed solutions on experimental data were presented and discussed. The current results will help to accurately calculate the fracture toughness or FCG rate of composites, further advancing the standardization process of composites testing based on SENT specimens. Evaluate the K and Compliance for orthotropic single edge notched tensile (SENT) specimens using 2D finite element analysis; The coupling effects of orthotropic parameters and geometric sizes are studied; Develop prediction equations for K and C of clamped SENT specimen; Propose a universal crack length estimation method based on the compliance; Discuss the application of the proposed equations to the tested data of UD CFRP. [ABSTRACT FROM AUTHOR]

Wind energy is a clean, sustainable, and renewable source. It is receiving a large amount of attention from governments and energy companies worldwide as it plays a significant role as an alternative source of energy in reducing carbon emissions. However, due to long-term operation in reduced and difficult weather conditions, wind turbine blades are always seriously damaged. Hence, damage detection in blade structure is essential to evaluate its operational condition and ensure its structural integrity and safety. We aim to use fractal, entropy, and chaos concepts as descriptors for the diagnosis of wind turbine blade condition. They are, respectively, estimated by the correlation dimension, approximate entropy, and the Lyapunov exponent. Formal statistical tests are performed to check how they are different across wind turbine blade conditions. The experimental results follow. First, the correlation dimension is not able to distinguish between all conditions of wind turbine blades. Second, approximate entropy is suitable to distinguish between healthy and erosion conditions and between healthy and mass imbalance conditions. Third, chaos is not a discriminative feature to distinguish between wind turbine blade conditions. Fourth, wind turbine blades with either erosion or mass imbalance exhibit less irregularity in their respective signals than healthy wind turbine blades. [ABSTRACT FROM AUTHOR]

This article raises the topic of the critical examination of polypropylene, a key polymeric material, and its extensive application within the automotive industry, particularly focusing on the manufacturing of brake fluid reservoirs. This study aims to enhance the understanding of polypropylene's behavior under mechanical stresses through a series of laboratory destruction tests and numerical simulations, emphasizing the finite element method (FEM). A novel aspect of this research is the introduction of the PEAK parameter, a groundbreaking approach designed to assess the material's resilience against varying states of strain, known as triaxiality. This parameter facilitates the identification of critical areas prone to crack initiation, thereby enabling the optimization of component design with a minimized safety margin, which is crucial for cost-effective production. The methodology involves conducting burst tests to locate crack initiation sites, followed by FEM simulations to determine the PEAK threshold value for the Sabic 83MF10 polypropylene material. The study successfully validates the predictive capability of the PEAK parameter, demonstrating a high correlation between simulated results and actual laboratory tests. This validation underscores the potential of the PEAK parameter as a predictive tool for enhancing the reliability and safety of polypropylene automotive components. The research presented in this article contributes significantly to the field of material science and engineering by providing a deeper insight into the mechanical behavior of polypropylene and introducing an effective tool for predicting crack initiation in automotive components. The findings hold promise for advancing the design and manufacturing processes in the automotive industry, with potential applications extending to other sectors. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Applied Mechanics is the property of Chinese Journal of Applied Mechanics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transportation Science & Technolgy is the property of Transportation Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Computational Mechanics / Jisuan Lixue Xuebao is the property of Chinese Journal of Computational Mechanics Editorial Office, Dalian University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: Crack cocaine use has increased rapidly throughout Mexico, along with rising HIV and hepatitis C virus (HCV) infections among vulnerable groups. The Tirando Esquina: Interviniendo Muros de Salud (TE:IMS) project uses projection-mapping technology and is the first of its kind to reach and provide health education at an individual and community level to at-risk crack smoking populations in Mexico City. Setting: This intervention project took place in Mexico City. Design: A single-arm design was utilised. Method: The TE:IMS intervention used projection mapping, a community-based art form wherein 3-dimensional (3-D) images, videos and graphics are projected onto buildings in the community. A total of nine projection mapping episodes were projected and health promoters engaged individuals on the street to reinforce messaging and distribute safer crack kits. A sample of persons who use crack (n = 58) were recruited prior to the intervention to complete pretest–posttest evaluation questionnaires. Results: Findings provide evidence of initial effectiveness. Decreases pre- to posttest were found in weekly crack use (p <.05), sharing of paraphernalia (p =.002) and use of cans as pipes (p =.008), while increases were observed in the usage of Pyrex pipes (p =.002). While quantitative HIV knowledge assessments did not increase significantly, qualitative data suggest the intervention made a substantial impact on perceptions and knowledge of HIV among those who interacted with the health promoters and saw the projections. Conclusions: TE: IMS was successful in providing health education and harm reduction strategies at a community level to at-risk crack smoking populations in Mexico City. These findings provide evidence for the initial effectiveness of innovative education and harm reduction efforts in this population. [ABSTRACT FROM AUTHOR]

AbstractPrediction of bone fracture risk is clinically challenging. Computational modeling plays a vital role in understanding bone structure and diagnosing bone diseases, leading to novel therapies. The research objectives were to demonstrate the anisotropic structure of the bone at the micro-level taking into consideration the density and subject demography, such as age, gender, body mass index (BMI), height, weight, and their roles in damage accumulation. Out of 438 developed 3D bone models at the micro-level, 46.12% were female. The age distribution ranged from 23 to 95 years. The research unfolds in two phases: micro-morphological features examination and stress distribution investigation. Models were developed using Mimics 22.0 and SolidWorks. The anisotropic material properties were defined before importing into Ansys for simulation. Computational simulations further uncovered variations in maximum von-Misses stress, highlighting that young Black males experienced the highest stress at 127.852 ± 10.035 MPa, while elderly Caucasian females exhibited the least stress at 97.224 ± 14.504 MPa. Furthermore, age-related variations in stress levels for both normal and osteoporotic bone micro models were elucidated, emphasizing the intricate interplay of demographic factors in bone biomechanics. Additionally, a prediction equation for bone density incorporating demographic variables was proposed, offering a personalized modeling approach. In general, this study, which carefully examines the complexities of how bones behave at the micro-level, emphasizes the need for an enhanced approach in orthopedics. We suggest taking individual characteristics into account to make therapeutic interventions more precise and effective. [ABSTRACT FROM AUTHOR]

In order to study the failure phenomenon and shear resistance performance of UHPC-NC beams without web reinforcement, shear resistance tests were carried out on 15 UHPC-NC beams without web reinforcement. The variation parameters were shear span ratio, web thickness, steel fiber content, and compressive stress level. The load-deflection curve, failure phenomenon and crack development of the test beam are analyzed. The test results show that the joint between the top plate and the bottom plate of UHPC-NC I-beam without web reinforcement is the weakest, and the cracked web is easy to be "cut off" at the joint; The "banding crack area" of web is closely related to the shear span ratio, and the width of ribbon area increases with the increase of shear span ratio. The shear capacity of UHPC-NC I-beam without web reinforcement decreases with the increase of shear-span ratio. The shear capacity increases with the increase of web thickness and compressive stress level. The shear capacity has little relationship with steel fiber content, and the initial stiffness of the structure can be improved by applying prestress. Finally, considering the influence of the top slab compression-shear zone and the bottom slab tension-shear zone on the shear capacity of UHPC-NC prestressed composite beams without web reinforcement, the corresponding calculation method of shear capacity is given based on the modified compression field theory and the idea of sub-item superposition, and the applicability of the calculation method is verified by the test results. [ABSTRACT FROM AUTHOR]

The purpose of this study is to analyze the features of a moving Griffith crack in an initially stressed infinitely long and finitely thick isotropic strip with moving parallel punches of constant load acting on its boundaries owing to plane wave propagation under point loading. Coupled singular integral equations and singularities of the Cauchy-type are used to formulate the present model, Dirac delta function is employed to analyze point load located at the moving crack edge, and Hilbert transformation properties are used for obtaining stress intensity factor (SIF) with constant point loading. Numerical simulations and graphical illustrations are performed to analyze the influences of the prevalent parameters, viz. initial stresses, punch pressure, distinct positions of point load, length and speed of the crack on the SIF for the considered isotropic material strip. [ABSTRACT FROM AUTHOR]

This paper investigates the mechanical properties and damage laws of marine shale from the Silurian Longmaxi Formation by conducting uniaxial compression experiments with varying lamination angles with respect to the loading direction. Data are analyzed via computed tomography scanning and fractal theory to reveal a series of mechanical properties, considering stress-strain curve, compressive strength, Young's modulus, and Poisson's ratio. The results indicate three damage modes in shale samples: shear, tensionshear, and tension. The shales are anisotropic as the mechanical properties vary with the lamination orientation and the loading direction. The compressive strength decreases nonlinearly with increasing lamination angle, whereas the Young's modulus and Poisson's ratio correlate almost linearly with the lamination angle. To overcome the defect of visual images when quantitatively evaluating cracks and rock damage to investigate the mechanical properties of shale, we propose block fractal dimension and crack fractal dimensions calculated using post-experimental photographs and computed tomography images. Fractal dimensions are useful tools for identifying variations in uniaxial compressive strength and correlate positively with the sample damage, particularly their damage class. This study highlights the value of applying fractal theory for the quantitative characterization of shale mechanical properties, and reveals that the lamination orientation to the loading direction is a parameter that significantly controls the mechanical properties of shale. [ABSTRACT FROM AUTHOR]

Under the far-field uniform tensile load, the crack tip will generate stress concentration, and the grain boundary adjacent to the crack tip will bear large shear stresses to cause nanograin boundary slip. The effects of hydrogen and nanoboundary slip on the crack nucleation, the critical stress intensity factor and the shielding action were investigated. The theoretical solution of the model was given with the continuous distributed dislocation method. The results show that, the wedge cracks preferentially germinate along direction DC of the grain boundary triple junction and grain boundary BD due to the plugging of the dislocation at the grain boundary triple junction and the tip of the slip plane. Moreover, hydrogen decreases the total energy of crack initiation. When hydrogen concentration increases by 1%, the total energy of the most stable crack initiation will decrease by about 1.86%. Although the grain boundary slip increases the critical stress intensity factor and the shielding action at the crack tip, hydrogen will decrease the critical stress intensity factor. Finally, according to the hydrogen enhanced decohesion (HEDE) theory, the influence of hydrogen on surface energy was studied. With every 1% increase of the hydrogen concentration, the surface energy will decrease by 5%. This theoretical work provides new information on the microscopic fracture mechanics of materials caused by hydrogen and grain boundary slip, and helps to explain the microscopic mechanism of metal fracture. [ABSTRACT FROM AUTHOR]

Kyiv Velodrome is the oldest sports facility in Ukraine and one of the oldest in Europe. In 2016-2017, the restoration of its track, administrative building, construction of an underground parking lot and reorganization of the adjacent territory were carried out. As part of the scientific and technical support, an examination of the velodrome track was carried out to determine all existing defects and damages and as a result, recommendations for their elimination were provided. In particular, solutions have been developed to repair cracks and recommended measures are aimed at preventing their appearance in the future. Also, within the scope of research work, some experimental studies were carried out with the designed constructions of the bicycle track for their compliance with the technical documentation and to establish durability (in laboratory conditions). The article analyzes and researches the structural and technological solutions proposed in the project documentation for the restoration and arrangement of the bicycle track, providing solutions and recommendations that will ensure the necessary quality and the project's design life. Thus, recommendations are being considered to reduce the likelihood of the appearance of new cracks and the development of existing ones on the track. [ABSTRACT FROM AUTHOR]

In the aeronautical construction several rivet holes are drilled, these holes constitute stress concentration zones which can be affects the fatigue life through cracks initiation at the edge of rivet holes. To remedy this problem and minimize stress level in these zones, the cold expansion technique is used to enhancing the fatigue life of rivet holes. The present work aims to investigate through finite element analysis the effect of three degree cold expansion (2%, 4.5% and 6%) on the reduction of stress level on the edge of rivet hole. The hole-crack interaction effect was thus analyzed. This effect is quantified by the values of JIntegral at the two tip of crack. The obtained results show that negative values of J-Integral was found which can be explained by the beneficial effect of residual compressive stresses induced by cold expansion on the crack closing. [ABSTRACT FROM AUTHOR]

Composite materials find extensive usage in industrial applications. However, they are susceptible to gradual damage over time. In this study, we explored the cracking processes in jute fiber-reinforced composite sheets subjected to uniaxial tension at varying displacement speeds (10, 20, and 30 mm/min) using Abaqus software. The composite plate dimensions are 25×35×10 mm³, with a 7 mm crack length. Our findings indicate that crack propagation in vehicle plates is influenced by mechanical properties relative to load, specifically through increased travel speed. We observed stress concentration around the crack, and the displacement speed significantly affects crack behavior. The cohesive J-integral was derived through finite element analysis, revealing a 90.90% relative error in the mean absolute value ΔJ across the five integral paths for the two sample types. Subsequently, five potential end conditions were assessed for further analysis, considering different boundary conditions: Simply supported (SSSS), two opposing sides clamped (SFSF), Clamped-Simply-Clamped-Simply (SCSC), two opposing sides clamped (CFCF), and all sides clamped (CCCC). Additionally, three different types of tensile actions in the y-direction were considered. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Epitaxial buffer layers such as ceria (CeO2)/yttria-stabilized zirconia (YSZ) allow the direct integration of functional oxide single crystal thin films on silicon (Si). Microcracks in the buffer layer, often evolving from the large thermal tensile stress, are detrimental to the integration of high-quality complex oxide thin films on Si. In this study, we investigated the evolution of microcracks in sputter-grown epitaxial CeO2 layers by systematically varying the sputtering power and thickness of CeO2 thin films on YSZ single crystal (low thermal mismatch) and YSZ-buffered Si (high thermal mismatch) substrates. Using a plane stress model, we revealed that as the sputtering power increased, the epitaxial CeO2 thin films tended to be more compressively strained at the growth temperature. This could accommodate the tensile strain arising during cooling to room temperature, thereby suppressing the evolution of microcracks. Our result provides not only a method to suppress microcracks in the oxide heterostructure on Si, but also a tool to control their strain state, by controlling their growth parameters. [ABSTRACT FROM AUTHOR]