Number Of Cycles Research Articles

Photodetector Devices: Investigation of ZnO Thin Films Fabricated via SILAR Technique on Various Substrates:

The synthesis of photodetectors for ZnO nanostructure films on various substrates, including p-type (100) silicon (Si), and porous silicon (pSi), has been achieved through the utilization of a straightforward technique known as the successive ionic layer adsorption and reaction (SILAR) method. To analyze the optical properties, surface morphology, and crystal structure of the ZnO layers, UV-Vis spectrometers, field emission scanning electron microscopes (FESEM), and X-ray diffraction (XRD) were employed. The characterization of the ZnO samples revealed that the number of SILAR cycles has a significant impact on the morphology and optical band gap of the synthesized layer. The Fourier-transform infrared (FTIR) spectrum successfully detected the distinctive extended vibration mode of ZnO. By conducting 20 cycles, high-quality hexagonal ZnO was obtained. The responsivity of the planar ZnO on silicon (ZnO/Si) and ZnO on the porous silicon (ZnO/pSi) surface exhibited variations depending on the substrate surface and bias voltage. The results indicated that the (ZnO/pSi) heterojunction demonstrated a high response in the visible range (350–850 nm) at a low bias voltage. On the other hand, the (ZnO/Si) photodetector displayed a high sensitivity of 666.66% at a low voltage of 1V in comparison to the (ZnO/pSi) photodetector, which exhibited a sensitivity of 483%.

A Biocompatible, Highly Sensitive, and Non-Enzymatic Glucose Electrochemical Sensor Based on a Copper-Cysteamine (Cu-Cy)/Chitosan-Modified Electrode.

A biocompatible, highly sensitive, and enzyme-free glucose electrochemical sensor was developed based on a copper-cysteamine (Cu-Cy)-modified electrode. The catalytically active biocompatible material Cu-Cy was immobilized on the electrode surface by the natural polymer chitosan (CTS). The electrochemical characterization and glucose response of the Cu-Cy/CTS/glassy carbon electrode (GCE) were investigated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and constant potential amperometry. The significant electrocatalytic activity of Cu-Cy to the oxidation of glucose in an alkaline environment was revealed. Several crucial parameters, including the number of scanning cycles for electrode activation, applied potential, and the contents of Cu-Cy and chitosan, were investigated to understand their impact on the sensor's response. The proposed sensing platform exhibited linear ranges of 2.7 μM to 1.3 mM and 1.3 mM to 7.7 mM for glucose detection, coupled with high sensitivity (588.28 and 124.42 μA·mM-1·cm-2), and commendable selectivity and stability. Moreover, a Cu-Cy/CTS-modified screen-printed electrode (SPE) was further developed for portable direct detection of glucose in real samples.

Paired coalition in graphs

A paired coalition in a graph G = ( V , E ) consists of two disjoint sets of vertices V 1 and V 2 , neither of which is a paired dominating set but whose union V 1 ∪ V 2 is a paired dominating set. A paired coalition partition (abbreviated pc-partition) in a graph G is a vertex partition π = { V 1 , V 2 , … , V k } such that each set V i of π is not a paired dominating set but forms a paired coalition with another set V j ∈ π . The paired coalition graph PCG ( G , π ) of the graph G with the pc-partition π of G, is the graph whose vertices correspond to the sets of π , and two vertices V i and V j are adjacent in PCG ( G , π ) if and only if their corresponding sets V i and V j form a paired coalition in G. In this paper, we initiate the study of paired coalition partitions and paired coalition graphs. In particular, we determine the paired coalition number of paths and cycles, obtain some results on paired coalition partitions in trees and characterize pair coalition graphs of paths, cycles and trees. We also characterize triangle-free graphs G of order n with PC ( G ) = n and unicyclic graphs G of order n with PC ( G ) = n − 2 .

Low-cycle fatigue of welded joint from steel of X70 strength class

Steels of X70 strength class are particularly widely used in the field of heavy engineering. One of the most important issues when choosing steel for structures is its behavior under cyclic loads. It is difficult to find a description of the behavior of all zones of the welded joint under fatigue. The purpose of this study was to determine the fatigue characteristics of welded joints made of the Russian analogue of S690QL steel with fixation of acoustic and magnetic parameters for their use in the diagnosis. The objects of the study were the samples from domestic steel of X70 strength class. The chemical composition was determined using optical emission spectrometry. The grinds for microstructural analysis were prepared according to the standard technique with etching in the metal. The fatigue test was carried out on a specialized test bench. The authors used the acoustic system AIS NRK-3 for acoustic measurements and the acoustic parameter D – as an informative parameter. A MA-412MM coercitimeter was applied to evalua­te the magnetic characteristics. The following were evaluated: residual magnetization Br , coercive force Hc , Hc/Br ratio. The smallest number of cycles corresponds to the deposited metal zone. The decrease in amplitude showed a significant variation in the behavior of the material depending on the junction zone. However, the curves for heat affected zone (HAZ) and the deposited metal are practically the same. HAZ differs to a lesser extent from the base metal than the deposited metal zone. The graph of the acoustic parameter in its form is the reverse of the magnetic characteristics graph. Thus, there is a minimum for the acoustic parameter, depending on the operating time, and a maximum for the magnetic characteristics. For both graphs, the extremum is the point corresponding to the operating time of 0.6.

Exploring Limit Cycles of Differential Equations through Information Geometry Unveils the Solution to Hilbert's 16th Problem.

The detection of limit cycles of differential equations poses a challenge due to the type of the nonlinear system, the regime of interest, and the broader context of applicable models. Consequently, attempts to solve Hilbert's sixteenth problem on the maximum number of limit cycles of polynomial differential equations have been uniformly unsuccessful due to failing results and their lack of consistency. Here, the answer to this problem is finally obtained through information geometry, in which the Riemannian metrical structure of the parameter space of differential equations is investigated with the aid of the Fisher information metric and its scalar curvature R. We find that the total number of divergences of |R| to infinity provides the maximum number of limit cycles of differential equations. Additionally, we demonstrate that real polynomial systems of degree n≥2 have the maximum number of 2(n-1)(4(n-1)-2) limit cycles. The research findings highlight the effectiveness of geometric methods in analyzing complex systems and offer valuable insights across information theory, applied mathematics, and nonlinear dynamics. These insights may pave the way for advancements in differential equations, presenting exciting opportunities for future developments.

A dual-recognition strategy based on pH-responsive molecularly imprinted membrane for highly selective capture of catecholamines: From construction to practical application

BackgroundCatecholamines (CAs) are involved in a wide range of physiological and pathological processes in the body and are progressively being used as important biomarkers for a variety of diseases. It is of great significance for accurate quantification of CAs to the diagnosis and treatment of diseases. However, the separation of CAs from complex biological matrices is still a great challenge due to the trace levels of CAs and the limited selectivity of existing pretreatment methods. ResultsIn this work, a dual-recognition imprinted membrane (BA-MIM) was developed to utilize the synergistic action of pH-responsive boron affinity and molecular imprinted cavities for highly selective capture and release of CAs. The prepared BA-MIM possessed remarkable adsorption capacity (maximum capacity, 43.3 mg g−1), desirable surface hydrophilicity (46.2°), superior selectivity (IF = 6.2, α = 14.3), as well as favorable reusability (number of cycles, 6 times). On this basis, an integrated analytical method based on BA-MIM extraction combined with ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was innovatively developed to highly selective separation, enrichment, and detection of CAs in rat brain tissue. Under the optimum conditions, a low quantitation limits (0.05–0.10 ng mL−1), wide linear range (10–1000 ng mL−1), good linearity (r2 > 0.99), and satisfactory recoveries (88.5%–98.5 %) were obtained for CAs. The proven method was further applied to kidney-yang-deficiency-syndrome (KYDS) group rat model, revealed the intrinsic connection between kidney disease and catecholamine metabolism. SignificanceThis work provides an excellent reference paradigm for the effective construction of dual-recognition functional membrane material to the high-selective analysis of trace targets in complex matrices. Additionally, this integrated analytical strategy demonstrates its efficiency, sustainability, versatility, and convenience, showing remarkable prospect in a variety of applications for biological sample analysis.

Fatigue-induced fracture assessment for FRP-steel bonding joints after seawater exposure

This paper investigates fatigue durability of FRP-steel double-lap shear bonded structure in seawater environment. Three simulated environments (original-salinity seawater dry-wet cycle, triple-salinity seawater dry-wet cycle, and triple-salinity seawater immersion) with 30-, 60-, and 90-day maintenance duration are tested. Experimental results indicate that both the quasit-static and fatigue strength are degraded by the seawater maintenance, and longer maintenance will lead to continued deterioration of the bonded joints. The failure/damage of bonded joints primarily originates from the bonding failure in the docking zone and extend towards the two ends. For a specific bonded joint, the load amplitude (∆F) and cycle number (N) can be approximated fitted by a linear logarithmic curve. Based on this observation, a prediction model of the cycle number (N) for the bonded joints is proposed, and comparison demonstrated that the prediction model can effectively assess the fatigue strength of GFRP-steel double-lap shear bonded joints after seawater maintenance. The findings of this study can offer both theoretical and experimental foundations for assessing the durability of FRP-steel bonded structures in seawater corrosion environments.

Study of the co-pyrolysis behavior and bio-oil characterization of walnut shell and polyethylene by thermogravimetric analyzer and bubbling fluidized bed

In the present work, co-pyrolysis experiments of walnut shell (WS), polyethylene (PE) and their blends were performed in the thermogravimetric analyzer and lab-scale bubbling fluidized bed reactor, to clarify co-pyrolysis behaviors, synergy interactions and pyrolysis oil properties. Besides, the HZSM-5 zeolite was used as the catalyst and its catalytic characteristics were studied. Results indicated that as PE mass ratio rose from 0 to 100 %, the initial temperature monotonically increased from 265.4 to 417.3 °C, while its terminal temperature progressively decreased from 668.3 to 527.5 °C, suggesting that the addition of PE was able to accelerate the pyrolysis of samples. The co-pyrolysis of blends was distinguished into three stages, with a negative interaction observed in the first stage and positive interactions found in second and third stages. Besides, in the bubbling fluidized bed experiments, the liquid phase product yield first elevated and then reduced with rising temperature, and a high temperature promoted the degradation of oxygen-containing compounds and enhanced aromatics generation. The synergistic interaction in the co-pyrolysis of WS and PE declined the liquid phase product yield while elevating the gas phase product yield. On the other hand, blending with PE facilitated the generation of alkanes and olefins, while inhibiting the contents of oxygen-containing components and aromatics, and simultaneously, the heavy oil fraction was increased. Finally, the carbon deposited on the surface of catalysts was amorphous carbons, and could be removed by oxidation process, whereas its catalytic properties progressively declined with rising cycle number, leading to a downtrend of aromatics and olefins and an opposite trend for oxygen-containing components.

Interface wear law and modeling between yarns in woven CMC under cyclic loading

Friction and wear between warp and weft yarns affect the mechanical behavior of woven CMC. This paper conducts tensile and fatigue testing on unidirectional and woven CMCs without interphase to examine the influence mechanism of friction and wear between yarns on woven CMCs. Linear reciprocating friction experiments between minicomposites are carried out to demonstrate the degradation relationship of the friction coefficient with the cycle number. Interface elements are established between yarns in woven CMC to obtain the transverse equivalent constitutive relationship of the weft yarns at different friction coefficients. In other words, the variation relationship of the transverse mechanical properties of the weft yarns with the cycle number is determined. This method is utilized to the fatigue life prediction of woven CMC under cyclic loading. It achieves precise predictions of the fatigue life of woven CMC, with the prediction accuracy within a scatter range of four times.

Segmentation of Heart Sound Signal Based on Multi-Scale Feature Fusion and Multi-Classification of Congenital Heart Disease.

Analyzing heart sound signals presents a novel approach for early diagnosis of pediatric congenital heart disease. The existing segmentation algorithms have limitations in accurately distinguishing the first (S1) and second (S2) heart sounds, limiting the diagnostic utility of cardiac cycle data for pediatric pathology assessment. This study proposes a time bidirectional long short-term memory network (TBLSTM) based on multi-scale analysis to segment pediatric heart sound signals according to different cardiac cycles. Mel frequency cepstral coefficients and dynamic characteristics of the heart sound fragments were extracted and input into random forest for multi-classification of congenital heart disease. The segmentation model achieved an overall F1 score of 94.15% on the verification set, with specific F1 scores of 90.25% for S1 and 86.04% for S2. In a situation where the number of cardiac cycles in the heart sound fragments was set to six, the results for multi-classification achieved stabilization. The performance metrics for this configuration were as follows: accuracy of 94.43%, sensitivity of 95.58%, and an F1 score of 94.51%. Furthermore, the segmentation model demonstrates robustness in accurately segmenting pediatric heart sound signals across different heart rates and in the presence of noise. Notably, the number of cardiac cycles in heart sound fragments directly impacts the multi-classification of these heart sound signals.

Mechanistic Analysis of Reflective Cracking Potential in Electrified Pavement with Inductive Charging System.

Electrified pavements with inductive charging systems provide an innovative way of providing continuous wireless power transfer to electric vehicles (EVs). Electrified pavements have unique construction methods, resulting in different mechanical and thermodynamic characteristics from traditional pavements. This study aimed to investigate the mechanistic design of electrified pavements to mitigate thermal-induced reflective cracking due to the inclusion of concrete slabs with inductive charging units (CUs) under an asphalt surface layer. Finite element (FE) models were developed to analyze the temperature profiles, pavement responses, and crack potential in electrified pavements. The fatigue model and Paris' law were utilized to evaluate crack initiation and propagation for different pavement designs. Within the allowable range for sufficient wireless charging efficiency, increasing the surface layer thickness had a noticeable benefit on mitigating crack initiation and propagation. The results indicate that increasing the asphalt surface layer thickness by 20 mm can delay crack initiation and propagation, resulting in a two to threefold increase in the number of cycles needed to reach the same crack length. Reflective cracking can also be retarded by the optimized design of the charging unit. Increasing the concrete slab thickness from 100 mm to 180 mm resulted in an approximately 20% increase in the number of cycles to reach the same crack length. Reducing the slab width and length (shortening joint spacing) could also effectively reduce the reflective cracking potential, with the slab length having a more significant influence. These findings highlight the importance of balancing charging efficiency and structural durability in the design of electrified pavements.

Durability Performance of CGF Stone Waste Road Base Materials under Dry-Wet and Freeze-Thaw Cycles.

The disposal of stone waste derived from the stone industry is a worldwide problem. The shortage of landfills, as well as transport costs and environmental pollution, pose a crucial problem. Additionally, as a substitute for cement that has high carbon emissions, energy consumption, and pollution, the disposal of stone wastes by utilizing solid waste-based binders as road base materials can achieve the goal of "waste for waste". However, the mechanical properties and deterioration mechanism of solid waste-based binder solidified stone waste as a road base material under complex environments remains incompletely understood. This paper reveals the durability performance of CGF all-solid waste binder (consisting of calcium carbide residue, ground granulated blast furnace slag, and fly ash) solidified stone waste through the macro and micro properties under dry-wet and freeze-thaw cycling conditions. The results showed that the dry-wet and freeze-thaw cycles have similar patterns of impacts on the CGF and cement stone waste road base materials, i.e., the stress-strain curves and damage forms were similar in exhibiting the strain-softening type, and the unconfined compressive strengths all decreased with the number of cycles and then tended to stabilize. However, the influence of dry-wet and freeze-thaw cycles on the deterioration degree was significantly different; CGF showed excellent resistance to dry-wet cycles, whereas cement was superior in freeze-thaw resistance. The deterioration grade of CGF and cement ranged from 36.15 to 47.72% and 39.38 to 47.64%, respectively, after 12 dry-wet cycles, whereas it ranged from 57.91 to 64.48% and 36.61 to 40.00% after 12 freeze-thaw cycles, respectively. The combined use of MIP and SEM confirmed that the deterioration was due to the increase in the porosity and cracks induced by dry-wet and freeze-thaw cycles, which in turn enhanced the deterioration phenomenon. This can be ascribed to the fact that small pores occupy the largest proportion and contribute to the deterioration process, and the deterioration caused by dry-wet cycles is associated with the formation of large pores through the connection of small pores, while the freeze-thaw damage is due to the increase in medium pores that are more susceptible to water intrusion. The findings provide theoretical instruction and technical support for utilizing solid waste-based binders for solidified stone waste in road base engineering.

Strain amplitude dependency of cyclic hardening/softening behavior of 490 N/mm2 class steel

Existing studies on the strain amplitude dependency of cyclic softening behavior in structural steels often involve limited cycles or strain amplitudes below 2.5%, failing to provide a comprehensive understanding of stabilized cyclic behavior. This study performed uniaxial tension–compression cyclic loading tests using SN490B structural steel under three loading patterns: constant, variable, and offset constant strain amplitudes. The cyclic hardening and softening behaviors and stress–strain hysteresis loops were compared. Under variable strain amplitude loading, the specimens were subjected to increasing and decreasing strain amplitudes to investigate the strain amplitude dependency of the cyclic hardening and softening behaviors. Under offset constant strain amplitude loading, mean strains were initially introduced in either the tension or compression strain range, followed by cyclic loading with a constant strain amplitude centered around the mean strains. The test results revealed the following: (1) Under constant strain amplitude cyclic loading, the material exhibited cyclic softening and hardening behaviors at strain amplitudes smaller than and larger than 0.5%, respectively; (2) Under variable strain amplitude cyclic loading, increased and reduced strain amplitudes resulted in cyclic hardening and softening behaviors, respectively. The cyclic hardening/softening behavior strongly depended on the strain amplitude. Applying a significant number of cycles after strain amplitude reduction resulted in the stress–strain curves closely resembling those under constant strain amplitude conditions; (3) Even under offset constant strain amplitude cyclic loading conditions with nonzero mean strain, the peak stresses and shapes of the hysteresis loops approached those under constant strain amplitude conditions without mean strain.

Quantitative Study on the Anticollapse Ability of Casing in Shale Gas Wells under Complex Load Conditions.

Implementing novel technologies, including the "well factory" model and zipper fracturing techniques, has become prevalent in shale gas development. During completion operations such as lowering casing and multistage fracturing, the casing is subjected to many complex loads, reducing its strength and increasing the risk of casing deformation. By establishing a casing wear model and conducting multistage cyclic loading experiments and numerical simulations, we analyzed the change rule of casing anticollapse strength under complex loads, developed a calculation method for casing comprehensive anticollapse ability under complex loads, and applied the method to an illustrative calculation. The study shows that the wear effect during completion has a negligible impact on the strength of the casing. The casing anticollapse strength exhibits a linear decline in correlation with the number of cycles. The zipper fracturing operation resulted in a nonuniform distribution of geo-stress around the well, and the casing anticollapse strength demonstrated a nearly linear decline in correlation with the nonuniformity of geo-stress. In the presence of both internal and external effects, the casing anticollapse strength exhibited a decline exceeding 15%, thereby increasing the risk of casing deformation. This research method can provide computational guidance for preventing casing deformation in field fracturing construction.

Low-cycle fatigue behaviour of concrete-filled double skin steel tubular (CFDST) members for wind turbine towers

Wind energy has the advantages of being clean and renewable. Wind turbine towers endure horizontal cyclic loads that could influence the performance of entire structure. To clarify the low-cycle fatigue behaviour of concrete-filled double skin steel tubular (CFDST) members, a total of 16 specimens were experimented. The hollow, slenderness, and axial compression ratios are specifically designed to clarify the effects on performance under constant amplitude loading and hysteretic loading conditions. The typical failure modes under both loading conditions and the relationship between loop strain, loop bearing capacity, loop energy dissipation, cycle number, and various degradation indices were analysed. Studies indicate that the failure mode under low-cycle fatigue loading is mainly local deformation, which includes transverse fracture occurring at the region between the steel tube and ribbed stiffener, the crushing concrete. Fatigue specimens with different amplitudes exhibit varying shapes of hysteresis responses. Higher amplitudes could enhance damage and significantly reduce fatigue life. Increasing the hollow and axial compression ratios boosts the energy dissipation capacity, and decreasing the slenderness ratio enhances the lateral resistance. A 2 % constant amplitude preload intensifies the degradation of bearing capacity and energy dissipation under subsequent constant amplitude loading.

Real-world outcomes of FOLFOXIRI plus bevacizumab in patients with metastatic colorectal cancer: the JSCCR-TRIPON study.

FOLFOXIRI plus bevacizumab is a standard first-line chemotherapy for patients with metastatic colorectal cancer (mCRC). However, due to the severe toxicities, this regimen is not widely used. There is limited data on the real-world efficacy and safety. We conducted a retrospective analysis of clinical data from mCRC patients who received FOLFOXIRI plus bevacizumab as first-line chemotherapy at 31 institutions. The initial dose was standardized according to the TRIBE regimen. Induction therapy was defined as a combination of oxaliplatin, irinotecan, and fluorouracil. Out of 104 patients who met the criteria, the median age was 58years (range, 16-72). 81% of patients had an eastern cooperative oncology group performance status (PS) of 0. An initial dose reduction was observed in 63% of patients. The median number of preplanned induction therapy cycles was 12 (range, 4-12). The completion of scheduled induction therapy cycles was observed in 45% of patients, with treatment-related toxicities being the main reason for discontinuation (63%). The median progression-free survival and overall survival were 12.8months (95% CI, 10.6-15.0) and 27.9months (95% CI 21.6-34.2), respectively. The objective response rate and disease control rate were 63.7% and 98.9%, respectively. The R0 resection rate was 21.2%. The main grade 3 or higher toxicities were neutropenia (51%), febrile neutropenia (10%), and nausea/vomiting (5%). No treatment-related deaths were observed. In a real-world clinical setting, FOLFOXIRI plus bevacizumab demonstrated efficacy and safety comparable to previous clinical trials.

Rotating bending fatigue behavior of high-pressure diecast AlSi10MgMn alloy based on T5 heat treatment parameters

Abstract The study investigates fatigue failure, a common phenomenon in machine elements subjected to cyclic stresses. The analysis emphasizes that the actual stress experienced by materials often falls below their tensile and yield strengths due to repetitive variable stresses, leading to fatigue damage. Fatigue life is measured by the number of cycles endured before failure. This paper focuses on the aluminum alloy of AlSi10MgMn, extensively used in manufacturing due to its strength, low density, and corrosion resistance. Experimental procedures encompassed tensile testing, microstructural examination, SEM analysis, and fatigue testing. Tensile tests provided initial stress values for fatigue testing. Microstructure analyses verified that heat-treated samples exhibited precipitates. SEM analysis disclosed microstructural characteristics, while fracture surface examinations demonstrated higher fatigue resistance in heat-treated specimens. Hardness measurements were conducted, with heat-treated samples showing higher values. Theoretical calculations based on stress and cycle numbers were compared to experimental fatigue results. The derived equations aligned well with the tests. Ultimately, the study underlines the importance of heat treatment on material behavior and fatigue resistance, shedding light on alloy performance and durability enhancement.

Leukomoid Reaction and Partial Exchange in an Infant with Pertussis

Introduction: Leukemoid reactions resulting from infections other than leukemia can present with serious clinical conditions. Pertussis infection, particularly before vaccination, can lead to severe pneumonia and may trigger a leukemoid reaction. This case is presented to highlight the relationship between severe pneumonia and leukemoid reaction in pertussis. Case Presentation: A 41-day-old baby girl, who had not yet been vaccinated against pertussis, was hospitalized in the pediatric intensive care unit with a diagnosis of severe pneumonia due to pertussis infection and required mechanical ventilation. A pronounced leukemoid reaction (144,000 cells/μL) was observed. Despite hydration and supportive treatment, a partial exchange was performed due to the elevated white blood cell count. Although there was partial improvement in the white blood cell count, the patient passed away on the 11th day of follow-up. Conclusions: There is a need for further case reports to determine the appropriate timing for initiating partial exchange treatment and the number of cycles required.

Effects of vetiver root on cracking of expansive soils and its mechanistic analysis

The study investigated the reinforcing effect of vetiver root on soil by conducting outdoor planting tests and indoor root tests. The cracking indexes of soil specimens with varying root contents were analyzed, and a statistical model was established to determine the relationship between the cracking indexes, the number of dry and wet cycles, and the root content. The study revealed the crack evolution law of vetiver-reinforced expansive soil. The study explored the mechanism of the vegetation root in inhibiting the cracking of expansive soil and determined the optimal planting density of vetiver grass through outdoor planting tests. The results indicate that: The surface crack rate (CR), total crack length (CL), and crack number (CN) in the root-soil specimen exhibited exponential growth with an increase in the number of wet and dry cycles. This growth was more pronounced during the first and second cycles. The vetiver root could effectively reduce soil crack formation, and the specimen's cracking resistance is positively correlated with the root content. With the root content increased, the CR, CN, and CL decreased. The logistic model is suited to the CL of added root soil. The logistic model is more suitable for the growth model of the CR of the expansive soil with low root content, while the Boltzmann model is more suitable for the growth model of the CR of the expansive soil with high root content. Width of crack (CW) is better suited to the DoseResp growth model. The Boltzmann model is more applicable to the CN in expansive soils with low reinforcement, while the logistic growth model is more suitable for the development of CN above 0.21% root content. The development of the crack network was influenced by two key factors: the root content and the number of wet and dry cycles. Under the condition of planting roots, the development of crack networks in expansive soil differs from that of expansive soil with added roots, and there is no clear pattern to follow. The inhibitory effect of the vetiver root on cracking of expansive soil is related to the planting density of vetiver.

Characterization of fatigue behavior of 3D printed pneumatic fluidic elastomer actuators

Soft robots have gained significant interest due to their high flexibility and adaptability to various working conditions. Recent advancements in engineering and innovative materials have enabled the design and production of sophisticated soft robotic systems with enhanced capabilities. This study aims to evaluate the fatigue behavior of bellow-type pneumatic soft actuators fabricated through fused filament fabrication (FFF) using thermoplastic polyurethane (TPU), compared to silicone rubber cast actuators. The actuators were equipped with resistive flex sensors to monitor bending motion, and fatigue tests were performed with cycles of inflation and deflation until failure. Results showed that 3D printed TPU actuators could withstand a significant number of cycles before failure, with an average of 6410 cycles at 3 bar pressure, compared to 3439 cycles at 1 bar pressure for the silicone actuators. The study identified a set of fabrication parameters that positively affect the durability of TPU actuators, providing valuable insights for replicating these results. Additionally, the study established a plausible range of utilization for 3D-printed FFF actuators in terms of the number of cycles they can endure, offering critical data for engineers and designers to make informed decisions about the design and application of these actuators in various practical scenarios. The findings demonstrate the potential of FFF for producing durable, long-lasting pneumatic soft actuators.