The poor degradability and limited recyclability of epoxy resins are key challenges hindering the efficient recycling of ex-service wind turbine blades(EWTBs).Herein,we proposed a selective degradation strategy for di...The poor degradability and limited recyclability of epoxy resins are key challenges hindering the efficient recycling of ex-service wind turbine blades(EWTBs).Herein,we proposed a selective degradation strategy for direct recycling and high-value recovery of epoxy resins by introducing degradable Schiff base groups into the molecular structure and utilizing the resulting oligomers as curing agents.To realize this strategy,a series of Schiff base compounds were synthesized using bio-based vanillin and diamines and subsequently functionalized with epichlorohydrin to yield bio-based epoxy resins.The cured epoxy resins demonstrated remarkable improvements in the mechanical properties of diglycidyl ether of bisphenol-A(DGEBA),with an increases of 44.49%in the tensile strength of 38.55%,bending strength,and impact strength of 71.20%.The introduction of dynamic Schiff base bonds enabled the selective degradation of the vanillin-2,2-bis[4-(4-aminophenoxy)phenyl]propane-based epoxy resin(VBEP)/DGEBA copolymer,producing 84.20% oligomers that can be directly recycled and reused.Replacing 30 wt% of the curing agent with the oligomer increased the tensile strength of the cured sample to 75.40 MPa,surpassing that of the cured DGEBA.Under simulated acid rain and seawater exposure,the copolymer exhibited a service life of 27 years at 40℃,significantly exceeding the currently reported service life of 20 years.This study presents a sustainable strategy for the direct recycling and high-value reuse of epoxy resin,offering a promising solution for EWTBs.展开更多
Conventional hydrometallurgy recycling process for treating wasted lithium-ion batteries(LIBs)typically results in the consumption of large amounts of corrosive leachates.Recent research on reusable leachate is expect...Conventional hydrometallurgy recycling process for treating wasted lithium-ion batteries(LIBs)typically results in the consumption of large amounts of corrosive leachates.Recent research on reusable leachate is expected to significantly improve the economic and environmental benefits,but is usually limited to specific and unique chemical reactions which could only apply to one type of metal elements.Herein,we report the co-extraction of multiple metal elements can be extracted without adding precipitates by mixed crystal co-precipitation,which enables the reusability of the leachate.We show that an oxalic acid(OA):choline chloride(ChCl):ethylene glycol(EG)type DES leachate system can leach transition metals from wasted LiNi_(x)Co_(y)Mn_(1-x-y)O_(2)(NCM)cathode materials with satisfactory efficiency(The time required for complete leaching at 120℃ is 1.5 h).The transition metals were then efficiently extracted(with a recovery efficiency of over 96%for all elements)by directly adding water without precipitants.Noteworthy,the leachate can be efficiently recovered by directly evaporating the added water.The successful realization of reusability of leachate for the synergistic extraction of multiple elements relies on the regulation of the mixed crystal co-precipitation coefficient,which is realized by rationally design the reaction condition(composition of leachate,temperature and time)and induces the extraction of originally soluble manganese element.Our strategy is expected to be generally applicable and highly competent for industrial applications.展开更多
Through reusing software test components, automated software testing generally costs less than manual software testing. There has been much research on how to develop the reusable test components, but few fall on how ...Through reusing software test components, automated software testing generally costs less than manual software testing. There has been much research on how to develop the reusable test components, but few fall on how to estimate the reusability of test conlponents for automated testing. The purpose of this paper is to present a method of minimum reusability estimation for automated testing based on the return on investment （ROI） model. Minimum reusability is a benchmark for the whole automated testing process. If the reusability in one test execution is less than the minimum reusability, some new strategies must be adopted ill the next test execution to increase the reusability. Only by this way, we can reduce unnecessary costs and finally get a return on the investment of automated testing.展开更多
In the present study, the effects of operating conditions on biocatalytic activity and stability of Novozym 435 for repeated-batch biodiesel production from free fatty acid （FFA） were investigated. Thermal deactivat...In the present study, the effects of operating conditions on biocatalytic activity and stability of Novozym 435 for repeated-batch biodiesel production from free fatty acid （FFA） were investigated. Thermal deactivation caused by increased operating temperature from 45 to 50 ℃ could seriously affect the reusability of Novozym 435. The deactivation of Novozym 435 during the esterification of oleic acid with ethanol tended to be stronger than that in the system with methanol. Under the optimal conditions, considering both biocatalytic activity and stability of the enzyme, Novozym 435 could be reused for 13 cycles for biodiesel productions from oleic acid and absolute alcohols （methanol and ethanol） with FFA conversions of at least 90%. The presence of 4%-5% water in ethanol significantly affected the reusability of Novozym 435. Changes in the surface morphology of Novozym 435 during the esterification with various conditions were observed. It was revealed that the reduction in catalytic activity was related to the swelling degree of the catalyst surface, Additionally, biodiesel production from low cost renewable feedstocks, such as palm fatty acid distillate （PFAD） and 95% ethanol was examined, The esterification of PFAD with 95% ethanol catalyzed by Novozym 435 in 10-repeated batch operation showed the similar results in FFA conversion as compared to those using oleic acid. Novozym 435 remained active and could maintain 97.6% of its initial conversion after being used for 10 hatches.展开更多
The most significant invention made in recent years to serve various applications is software.Developing a faultless software system requires the soft-ware system design to be resilient.To make the software design more...The most significant invention made in recent years to serve various applications is software.Developing a faultless software system requires the soft-ware system design to be resilient.To make the software design more efficient,it is essential to assess the reusability of the components used.This paper proposes a software reusability prediction model named Flexible Random Fit(FRF)based on aging resilience for a Service Net(SN)software system.The reusability predic-tion model is developed based on a multilevel optimization technique based on software characteristics such as cohesion,coupling,and complexity.Metrics are obtained from the SN software system,which is then subjected to min-max nor-malization to avoid any saturation during the learning process.The feature extrac-tion process is made more feasible by enriching the data quality via outlier detection.The reusability of the classes is estimated based on a tool called Soft Audit.Software reusability can be predicted more effectively based on the pro-posed FRF-ANN(Flexible Random Fit-Artificial Neural Network)algorithm.Performance evaluation shows that the proposed algorithm outperforms all the other techniques,thus ensuring the optimization of software reusability based on aging resilient.The model is then tested using constraint-based testing techni-ques to make sure that it is perfect at optimizing and making predictions.展开更多
The quality factor of class diagram is critical because it has a significant influence on overall quality of the product, delivered finally. Testability analysis, when done early in the software creation process, is a...The quality factor of class diagram is critical because it has a significant influence on overall quality of the product, delivered finally. Testability analysis, when done early in the software creation process, is a criterion of critical importance to software quality. Reusability is an important quality factor to testability. Its early measurement in object oriented software especially at design phase, allows a design to be reapplied to a new problem without much extra effort. This research paper proposes a research framework for quantification process and does an extensive review on reusability of object oriented software. A metrics based model “Reusability Quantification of Object Oriented Design” has been proposed by establishing the relationship among design properties and reusability and justifying the correlation with the help of statistical measures. Also, “Reusability Quantification Model” is empirically validated and contextual significance of the study shows the high correlation for model acceptance. This research paper facilitates to software developers and designer, the inclusion of reusability quantification model to access and quantify software reusability for quality product.展开更多
Due to rapid development in software industry, it was necessary to reduce time and efforts in the software development process. Software Reusability is an important measure that can be applied to improve software deve...Due to rapid development in software industry, it was necessary to reduce time and efforts in the software development process. Software Reusability is an important measure that can be applied to improve software development and software quality. Reusability reduces time, effort, errors, and hence the overall cost of the development process. Reusability prediction models are established in the early stage of the system development cycle to support an early reusability assessment. In Object-Oriented systems, Reusability of software components (classes) can be obtained by investigating its metrics values. Analyzing software metric values can help to avoid developing components from scratch. In this paper, we use Chidamber and Kemerer (CK) metrics suite in order to identify the reuse level of object-oriented classes. Self-Organizing Map (SOM) was used to cluster datasets of CK metrics values that were extracted from three different java-based systems. The goal was to find the relationship between CK metrics values and the reusability level of the class. The reusability level of the class was classified into three main categorizes (High Reusable, Medium Reusable and Low Reusable). The clustering was based on metrics threshold values that were used to achieve the experiments. The proposed methodology succeeds in classifying classes to their reusability level (High Reusable, Medium Reusable and Low Reusable). The experiments show how SOM can be applied on software CK metrics with different sizes of SOM grids to provide different levels of metrics details. The results show that Depth of Inheritance Tree (DIT) and Number of Children (NOC) metrics dominated the clustering process, so these two metrics were discarded from the experiments to achieve a successful clustering. The most efficient SOM topology [2 × 2] grid size is used to predict the reusability of classes.展开更多
This paper analyzes the launch price of the launch vehicles, domestic and abroad, studies the status and trend of the low cost launch vehicles, and introduces two measures to reduce the cost by means of evolved and di...This paper analyzes the launch price of the launch vehicles, domestic and abroad, studies the status and trend of the low cost launch vehicles, and introduces two measures to reduce the cost by means of evolved and disruptive technologies, utilizing the concept of low cost manufacturing and operating modes as well. This paper also analyzes the launch strategies for small satellites such as piggyback, networking launch, and single launch with a small launch vehicle(SLV). Finally, the development trend of reusable launch vehicles is discussed as well as the development prospects for China's reusable launch vehicle.展开更多
Large-area and free-standing photonic crystal(PC)polymer films exhibit highly saturated iridescence and robust structural colors,making them promising for applications in the field of display,anti-counterfeiting,and c...Large-area and free-standing photonic crystal(PC)polymer films exhibit highly saturated iridescence and robust structural colors,making them promising for applications in the field of display,anti-counterfeiting,and camouflage.However,their practical utilization has been hindered by challenges in achieving both vivid coloration and reusability.Here,we design a sandwich-structured PC film that simultaneously addresses issues of color appearance and reusability by combining colloid evaporative self-assembly on porous substrate and knife coating of polymers.The unique“sandwich”structure,comprising a self-assembled PC intermediate layer and protective polymer encapsulation,demonstrates a great synergistic effect(“1+1>2”),including unprecedented color fastness stability(affordable for 100 times dye/wet fastness),bright iridescent color,and certain flexibility and reusability.In addition,by replacing the bottom polymer with a double-sided adhesive,a flexible PC sticker can be further obtained,broadening its range of applications to surfaces of different materials.This strategy opens a new avenue for constructing functionalized iridescent PC-polymer films.展开更多
The COVID-19 pandemic has exposed the limitations of traditional preventative measures and underscored the essential role of face masks in controlling virus transmission.More effective and recyclable facial masks usin...The COVID-19 pandemic has exposed the limitations of traditional preventative measures and underscored the essential role of face masks in controlling virus transmission.More effective and recyclable facial masks using various materials have been developed.In this work,vertically aligned carbon nanotubes(VACNTs)are employed as effective facial mask filters,particularly aimed at preventing SARS-CoV-2 virus infection in preparation for future COVID-19 pandemics.This study assesses six critical aspects of facial masks:hydrophobicity,industrial viability,breathability,hyperthermal antiviral effect,toxicity,and reusability.The VACNT alone exhibits superhydrophobicity with a contact angle of 175.53◦,and an average of 142.7◦for a large area on spun-bonded polypropylene.VACNTs are processed using a roll-to-roll method,eliminating the need for adhesives.Due to the aligned tubes,VACNT filters demonstrate exceptional breathability and moisture ventilation compared to previously reported CNT and conventional filters.Hyperthermal tests of VACNT filters under sunlight confirm that up to 99.8%of the HCoV 229E virus denatures even in cold environments.The safety of using VACNTs is corroborated through histopathological evaluation and subcutaneous implantation tests,addressing concerns of respiratory and skin inflammation.VACNT masks efficiently transmit moisture and rapidly return to their initial dry state under sunlight maintaining their properties after 10000 bending cycles.In addition,the unique capability of VACNT filters to function as respiratory sensors,signaling dampness and facilitating reuse,is assessed,alongside their Joule heating effect.展开更多
It is well known that static seals are usually designed to be used once. In this paper, we discuss the reusability of a type of static seal called the spring energized metal C ring, which is required to be reused 4-5 ...It is well known that static seals are usually designed to be used once. In this paper, we discuss the reusability of a type of static seal called the spring energized metal C ring, which is required to be reused 4-5 times without maintenance during the lifetime of the pump. A theoretical analysis based on the nonlinear finite element method and an experimental investigation of the reusability of the C ring are carried out. The effects of the elastic modulus of the ring material, the ring wall thickness, the amount of assembly interference between the spring and the C ring, the operating temperature and the compression ratio are discussed. The parameter S, which denotes the reaction force difference percentage, is determined to measure the reusability of the C ring. The results show that the ring wall thickness plays an important role in the reusability. Although the normal force of a thick wall decreases after the ring is reused eight times, the value is still higher than the first normal force of a thin wall. In contrast, the elastic modulus of the material has the lowest impact. Here, a pre-compression ratio of 18.2% not only produces a larger first normal force but also leads to a smaller reduction in the normal force when the ring is reused. A simulated experiment is carried out to investigate the influence of the coating of the C ring on its reusability. The results show that when plastic deformation occurs on the contact surface, the contact state of the C ring coating becomes a major factor that affects the seal performance. Aging treatment at high temperatures （250℃） reduces gized metal C ring, which leads to the deterioration in the reusability the binding force of the silver coating on the spring ener of the ring.展开更多
Artificial neural networks(ANNs),a branch of artificial intelligence,has become a very interesting domain since the eighties when back-propagation(BP)learning algorithm for multilayer feed-forward architecture was int...Artificial neural networks(ANNs),a branch of artificial intelligence,has become a very interesting domain since the eighties when back-propagation(BP)learning algorithm for multilayer feed-forward architecture was introduced to solve nonlinear problems.It is used extensively to solve complex nonalgorithmic problems such as prediction,pattern recognition and clustering.However,in the context of a holistic study,there may be a need to integrate ANN with other models developed in various paradigms to solve a problem.In this paper,we suggest discrete event system specification(DEVS)be used as a model of computation(MoC)to make ANN models interoperable with other models(since all discrete event models can be expressed in DEVS,and continuous models can be approximated by DEVS).By combining ANN and DEVS,we can model the complex configuration of ANNs and express its internal workings.Therefore,we are extending the DEVS-based ANN proposed by Toma et al.[A new DEVS-based generic art-ficial neural network modeling approach,The 23rd European Modeling and Simulation Symp.(Simulation in Industry),Rome,Italy,2011]for comparing multiple configuration parameters and learning algorithms and also to do prediction.The DEVS models are described using the high level language for system specification(HiLLS),[Ma¨ıga et al.,A new approach to modeling dynamic structure systems,The 29th European Modeling and Simulation Symp.(Simulation in Industry),Leicester,United Kingdom,2015]a graphical modeling language for clarity.The developed platform is a tool to transform ANN models into DEVS computational models,making them more reusable and more interoperable in the context of larger multi-perspective modeling and simulation(MAS).展开更多
The radiative heat flux of the plume from reusable rockets is a critical parameter during the launch and return processes.This paper proposes a method for calculating radiative heat flux with higher accuracy than prev...The radiative heat flux of the plume from reusable rockets is a critical parameter during the launch and return processes.This paper proposes a method for calculating radiative heat flux with higher accuracy than previously reported for a recoverable nine-engine liquid-propellant rocket.Based on the Radiative Transfer Equation(RTE),this study employs the discrete transfer method to solve the transient RTE problem using physical properties to describe the problem while avoiding the need to directly solve mathematical equations.The proposed method can effectively determine the radiative heat flux of the flow field and is applicable to problems involving various geometries.Calculations reveal that during the ascent phase of the rocket,the radiative heat flux at the base of the vehicle reaches its maximum in the initial stages of the lift-off,reaching a maximum of~50 kW/m^(2),which is 2.24 times the maximum value during the return phase.During the deceleration stage of re-entry into the atmosphere,the maximum radiative heat flux recorded on the sidewall of the rocket is 29.1 kW/m^(2);the maximum heat flux on the bottom surface is approximately 22.3 kW/m^(2),accounting for 76.6%of that on the rocket's sidewall.This provides a basis for the thermal protection design of the rocket's bottom and walls as well as for the thermal management of cryogenic propellant tanks.Future research will involve ground engine testing and flight experiments to further validate the proposed model.展开更多
Herein,a reusable and portable surface-enhanced Raman spectroscopy(SERS)sandpaper was successfully synthesized for the sensitive detection of S-fenvalerate in foods.Commercial sandpapers were decorated with Ag@SiO2@Au...Herein,a reusable and portable surface-enhanced Raman spectroscopy(SERS)sandpaper was successfully synthesized for the sensitive detection of S-fenvalerate in foods.Commercial sandpapers were decorated with Ag@SiO2@Au nanoarrays via a liquid-liquid interface self-assembly method.The capacity of sandpaper to float directly on the cyclohexane-water interface allows nanoarrays to be formed directly on it,thereby minimizing stacking issues typically associated with nanoarray assemblies and significantly enhancing the sensitivity of S-fenvalerate detection.Moreover,the SERS sandpaper was reusable and portable due to its strong adhesion of the nanoarrays.Under optimized testing conditions,the developed SERS sandpaper method was capable of detecting S-fenvalerate,demonstrating a strong linear response within a concentration range of 10^(–7)–10^(3)μmol/L,with a limit of detection of 1.92×10^(−8)μmol/L.The analysis of spiked food samples containing S-fenvalerate using the developed SERS sandpaper afforded excellent recoveries(92.2%−109.7%).Additionally,the SERS sandpaper was successfully applied to quantify S-fenvalerate in real food samples,with results consistent with analyses conducted using gas chromatography.展开更多
This study demonstrates the valorization of macadamia nutshells,a lignocellulosic agricultural waste,as both a carbon source for amylase production and a support matrix for enzyme immobilization.Under optimized solid-...This study demonstrates the valorization of macadamia nutshells,a lignocellulosic agricultural waste,as both a carbon source for amylase production and a support matrix for enzyme immobilization.Under optimized solid-state fermentation conditions,Aspergillus niger ICP2 synthesized amylase with a peak activity of 0.312 U/mL after 72 hours.A four-step purification process of the crude enzyme extract resulted in a 188.54-fold increase in specific activity,albeit with a final recovery yield of 0.0031%.In parallel,nutshells were carbonized at 600℃,700℃,and 800℃,then chemically activated with ZnCl_(2).The carbon derived at 700℃ exhibited superior physicochemical characteristics,including enhanced porosity and increased availability of functional groups,which enabled effective enzyme adsorption,improved catalytic performance,and enhanced reusability.Immobilized amylase on this support retained approximately 30% of its initial activity after five hydrolysis cycles,demonstrating moderate operational reusability and potential for repeated use in bioprocesses.In contrast,carbon materials from 600℃ and 800℃ showed lower stability and enzyme performance.These findings highlight the critical role of carbonization conditions in designing effective immobilization matrices and underscore the potential of macadamia nutshells as a renewable and sustainable resource for biocatalyst development.This“biowaste-to-biocatalyst”strategy exemplifies a circular bioeconomy model with implications for green chemistry,industrial biocatalysis,and environmental sustainability.展开更多
Achieving vibration isolation,lightweight design,and reusability under impact remains a critical challenge for thin-walled structures.When the goat skull is subjected to impact,both the outer wall of the sinus and the...Achieving vibration isolation,lightweight design,and reusability under impact remains a critical challenge for thin-walled structures.When the goat skull is subjected to impact,both the outer wall of the sinus and the internal bony struts deform simultaneously to absorb energy and protect intracranial tissues.Inspired by this mechanism,we designed the goat sinus-inspired bio mimetic(GSIB) structure by mimicking the outer wall of the sinus and the internal pillar-like support system.The structure consists of dual coupling beams,including a set of inclined cantilever beams representing the sinus outer wall and vertical support beams simulating the internal bony struts.The GSIB structure was fabricated using Selective Laser Sintering(SLS) 3D printing technology,and its mechanical properties were investigated through a combination of quasi-static compression tests,vibration tests,impact tests,and finite element simulations.Under compressive loading,the inclined cantilever beams buckle to introduce a negative stiffness effect,while the vertical supports enhance overall stiffness.Leveraging the coupling effect between these two components,the structure achieves a long-stroke constant-force response,thereby delivering superior performance in energy absorption and vibration isolation.Additionally,the special deformation mode of the GSIB structure enables it to be reused under impact conditions.It is noteworthy that,compared to the negative stiffness(NS) structure with the same dimensions for repeated buffering proposed in previous studies,the GSIB structure demonstrates an energy absorption capacity reaching 214.3% of that of the NS structure,a reduction in isolation frequency to 58.5%,and an impact acceleration that is only 66.31% of that of the NS structure.Additionally,the plateau stress of the proposed structure increases to 246.07% of that of the NS structure.This novel artificial structure provides a new design strategy for achieving superior energy absorption and impact resistance under repeated impact conditions.展开更多
Excessive Fe^(3+) ion concentrations in wastewater pose a long-standing threat to human health.Achieving low-cost,high-efficiency quantification of Fe^(3+) ion concentration in unknown solutions can guide environmenta...Excessive Fe^(3+) ion concentrations in wastewater pose a long-standing threat to human health.Achieving low-cost,high-efficiency quantification of Fe^(3+) ion concentration in unknown solutions can guide environmental management decisions and optimize water treatment processes.In this study,by leveraging the rapid,real-time detection capabilities of nanopores and the specific chemical binding affinity of tannic acid to Fe^(3+),a linear relationship between the ion current and Fe^(3+) ion concentration was established.Utilizing this linear relationship,quantification of Fe^(3+) ion concentration in unknown solutions was achieved.Furthermore,ethylenediaminetetraacetic acid disodium salt was employed to displace Fe^(3+) from the nanopores,allowing them to be restored to their initial conditions and reused for Fe^(3+) ion quantification.The reusable bioinspired nanopores remain functional over 330 days of storage.This recycling capability and the long-term stability of the nanopores contribute to a significant reduction in costs.This study provides a strategy for the quantification of unknown Fe^(3+) concentration using nanopores,with potential applications in environmental assessment,health monitoring,and so forth.展开更多
Due to their high mechanical compliance and excellent biocompatibility,conductive hydrogels exhibit significant potential for applications in flexible electronics.However,as the demand for high sensitivity,superior me...Due to their high mechanical compliance and excellent biocompatibility,conductive hydrogels exhibit significant potential for applications in flexible electronics.However,as the demand for high sensitivity,superior mechanical properties,and strong adhesion performance continues to grow,many conventional fabrication methods remain complex and costly.Herein,we propose a simple and efficient strategy to construct an entangled network hydrogel through a liquid-metal-induced cross-linking reaction,hydrogel demonstrates outstanding properties,including exceptional stretchability(1643%),high tensile strength(366.54 kPa),toughness(350.2 kJ m^(−3)),and relatively low mechanical hysteresis.The hydrogel exhibits long-term stable reusable adhesion(104 kPa),enabling conformal and stable adhesion to human skin.This capability allows it to effectively capture high-quality epidermal electrophysiological signals with high signal-to-noise ratio(25.2 dB)and low impedance(310 ohms).Furthermore,by integrating advanced machine learning algorithms,achieving an attention classification accuracy of 91.38%,which will significantly impact fields like education,healthcare,and artificial intelligence.展开更多
BACKGROUND Single-use duodenoscopes(SDs)were introduced to eliminate exogenous infection risks post-endoscopic retrograde cholangiopancreatography(ERCP).AIM To evaluate their efficacy and safety against reusable duode...BACKGROUND Single-use duodenoscopes(SDs)were introduced to eliminate exogenous infection risks post-endoscopic retrograde cholangiopancreatography(ERCP).AIM To evaluate their efficacy and safety against reusable duodenoscopes(RDs).METHODS This was a single-center case control study.All consecutive patients undergoing ERCP using SD between 2020 and 2023 were enrolled.A similar number of patients undergoing ERCP using RD were randomly selected and enrolled.In case of ERCP failure using SD,operators switched to a RD if judged appropriate.The primary outcome was successful ERCP completion rates.The secondary outcomes were rate of difficult biliary cannulation,incidence of crossover from SD to RD,procedure related adverse events,30-day re-admission rate,and endoscopists'assessment of SD's performance.RESULTS A total of 133 patients were enrolled(n=53 for SD,n=80 for RD).Baseline characteristics and American Society for Gastrointestinal Endoscopy ERCP complexity grades were comparable between both groups.Successful ERCP completion rates were 88.7%for SD and 95%for RD(P=0.3).In cases of unsuccessful ERCP with SD,crossover to RD occurred in 3 out of 6 instances,with 2 subsequently succeeding with RD.Rates of adverse events and 30-day readmission were comparable:(1)13.2%vs 11.2%(P=0.19);and(2)15.4%vs 8.9%(P=0.25),respectively.Median overall endoscopists’satisfaction with SD was 8 out of 10.CONCLUSION The novel SDs demonstrated no difference in efficacy and safety compared to conventional RDs when used to perform a wide range of ERCPs.Nevertheless,further development and study of SDs’financial and environmental effectiveness is warranted.展开更多
An optimal feedback guidance law with disturbance rejection objective is proposed for endoatmospheric powered descent.This guidance law with an affine form is derived by solving a novel problem called Endoatmospheric ...An optimal feedback guidance law with disturbance rejection objective is proposed for endoatmospheric powered descent.This guidance law with an affine form is derived by solving a novel problem called Endoatmospheric Powered Descent Guidance with Disturbance Rejection(Endo-PDG-DR).The key idea of formulating the Endo-PDG-DR problem is dividing disturbances into two parts,modeled and unmodeled disturbances:the modeled disturbance is proactively exploited by augmenting it as a new state of a dynamics model;the unmodeled disturbance is reactively attenuated in terms of its effect on the guidance performance by adjoining a parameterized time-varying quadratic performance index in the proposed optimal guidance problem.A Pseudospectral Differential Dynamic Programming(PDDP)method is developed to solve the Endo-PDG-DR problem,and correspondingly a robust neighboring optimal state feedback law is obtained,which has two synergistic functionalities.One is adaptive optimal steering to accommodate the modeled disturbance,and the other is disturbance attenuation to compensate for the state perturbation effect induced by the unmodeled disturbance.Using the derived feedback guidance law,a disturbance rejection level is quantified,and is correspondingly optimized by designing a quadratic weighting parameter tuning law.The numerical computations of interest are performed within a pseudospectral setting,ensuring polynomial analytical solution,high computational efficiency,and reliable convergence.展开更多
基金financially supported by the National Natural Science Foundation of China(No.U23A20691)Innovation Group of National Ethnic Affairs Commission of China(No.MZR20006)+2 种基金Fund for Academic Innovation Teams of SouthCentral Minzu University(No.XTZ24012)Fundamental Research Fund for the Central Universities of South-Central Minzu University(Nos.CZD24001 and CZQ25012)Scientific Research Fund of South-Central Minzu University(No.YZY25007)。
文摘The poor degradability and limited recyclability of epoxy resins are key challenges hindering the efficient recycling of ex-service wind turbine blades(EWTBs).Herein,we proposed a selective degradation strategy for direct recycling and high-value recovery of epoxy resins by introducing degradable Schiff base groups into the molecular structure and utilizing the resulting oligomers as curing agents.To realize this strategy,a series of Schiff base compounds were synthesized using bio-based vanillin and diamines and subsequently functionalized with epichlorohydrin to yield bio-based epoxy resins.The cured epoxy resins demonstrated remarkable improvements in the mechanical properties of diglycidyl ether of bisphenol-A(DGEBA),with an increases of 44.49%in the tensile strength of 38.55%,bending strength,and impact strength of 71.20%.The introduction of dynamic Schiff base bonds enabled the selective degradation of the vanillin-2,2-bis[4-(4-aminophenoxy)phenyl]propane-based epoxy resin(VBEP)/DGEBA copolymer,producing 84.20% oligomers that can be directly recycled and reused.Replacing 30 wt% of the curing agent with the oligomer increased the tensile strength of the cured sample to 75.40 MPa,surpassing that of the cured DGEBA.Under simulated acid rain and seawater exposure,the copolymer exhibited a service life of 27 years at 40℃,significantly exceeding the currently reported service life of 20 years.This study presents a sustainable strategy for the direct recycling and high-value reuse of epoxy resin,offering a promising solution for EWTBs.
基金supported by The National Natural Science Foundation of China(No.52262030)Natural Science Research Project of Guizhou Provincial Department of Education(No.[2022]041).
文摘Conventional hydrometallurgy recycling process for treating wasted lithium-ion batteries(LIBs)typically results in the consumption of large amounts of corrosive leachates.Recent research on reusable leachate is expected to significantly improve the economic and environmental benefits,but is usually limited to specific and unique chemical reactions which could only apply to one type of metal elements.Herein,we report the co-extraction of multiple metal elements can be extracted without adding precipitates by mixed crystal co-precipitation,which enables the reusability of the leachate.We show that an oxalic acid(OA):choline chloride(ChCl):ethylene glycol(EG)type DES leachate system can leach transition metals from wasted LiNi_(x)Co_(y)Mn_(1-x-y)O_(2)(NCM)cathode materials with satisfactory efficiency(The time required for complete leaching at 120℃ is 1.5 h).The transition metals were then efficiently extracted(with a recovery efficiency of over 96%for all elements)by directly adding water without precipitants.Noteworthy,the leachate can be efficiently recovered by directly evaporating the added water.The successful realization of reusability of leachate for the synergistic extraction of multiple elements relies on the regulation of the mixed crystal co-precipitation coefficient,which is realized by rationally design the reaction condition(composition of leachate,temperature and time)and induces the extraction of originally soluble manganese element.Our strategy is expected to be generally applicable and highly competent for industrial applications.
基金Foundation item： the National Natural Science Foundation of China （No. 90718037）
文摘Through reusing software test components, automated software testing generally costs less than manual software testing. There has been much research on how to develop the reusable test components, but few fall on how to estimate the reusability of test conlponents for automated testing. The purpose of this paper is to present a method of minimum reusability estimation for automated testing based on the return on investment （ROI） model. Minimum reusability is a benchmark for the whole automated testing process. If the reusability in one test execution is less than the minimum reusability, some new strategies must be adopted ill the next test execution to increase the reusability. Only by this way, we can reduce unnecessary costs and finally get a return on the investment of automated testing.
基金the National Research Council of Thailand (NRCT) for financial supportthe 90th anniversary of Chulalongkorn University (Ratchadaphiseksomphot Endowment Fund)
文摘In the present study, the effects of operating conditions on biocatalytic activity and stability of Novozym 435 for repeated-batch biodiesel production from free fatty acid （FFA） were investigated. Thermal deactivation caused by increased operating temperature from 45 to 50 ℃ could seriously affect the reusability of Novozym 435. The deactivation of Novozym 435 during the esterification of oleic acid with ethanol tended to be stronger than that in the system with methanol. Under the optimal conditions, considering both biocatalytic activity and stability of the enzyme, Novozym 435 could be reused for 13 cycles for biodiesel productions from oleic acid and absolute alcohols （methanol and ethanol） with FFA conversions of at least 90%. The presence of 4%-5% water in ethanol significantly affected the reusability of Novozym 435. Changes in the surface morphology of Novozym 435 during the esterification with various conditions were observed. It was revealed that the reduction in catalytic activity was related to the swelling degree of the catalyst surface, Additionally, biodiesel production from low cost renewable feedstocks, such as palm fatty acid distillate （PFAD） and 95% ethanol was examined, The esterification of PFAD with 95% ethanol catalyzed by Novozym 435 in 10-repeated batch operation showed the similar results in FFA conversion as compared to those using oleic acid. Novozym 435 remained active and could maintain 97.6% of its initial conversion after being used for 10 hatches.
文摘The most significant invention made in recent years to serve various applications is software.Developing a faultless software system requires the soft-ware system design to be resilient.To make the software design more efficient,it is essential to assess the reusability of the components used.This paper proposes a software reusability prediction model named Flexible Random Fit(FRF)based on aging resilience for a Service Net(SN)software system.The reusability predic-tion model is developed based on a multilevel optimization technique based on software characteristics such as cohesion,coupling,and complexity.Metrics are obtained from the SN software system,which is then subjected to min-max nor-malization to avoid any saturation during the learning process.The feature extrac-tion process is made more feasible by enriching the data quality via outlier detection.The reusability of the classes is estimated based on a tool called Soft Audit.Software reusability can be predicted more effectively based on the pro-posed FRF-ANN(Flexible Random Fit-Artificial Neural Network)algorithm.Performance evaluation shows that the proposed algorithm outperforms all the other techniques,thus ensuring the optimization of software reusability based on aging resilient.The model is then tested using constraint-based testing techni-ques to make sure that it is perfect at optimizing and making predictions.
文摘The quality factor of class diagram is critical because it has a significant influence on overall quality of the product, delivered finally. Testability analysis, when done early in the software creation process, is a criterion of critical importance to software quality. Reusability is an important quality factor to testability. Its early measurement in object oriented software especially at design phase, allows a design to be reapplied to a new problem without much extra effort. This research paper proposes a research framework for quantification process and does an extensive review on reusability of object oriented software. A metrics based model “Reusability Quantification of Object Oriented Design” has been proposed by establishing the relationship among design properties and reusability and justifying the correlation with the help of statistical measures. Also, “Reusability Quantification Model” is empirically validated and contextual significance of the study shows the high correlation for model acceptance. This research paper facilitates to software developers and designer, the inclusion of reusability quantification model to access and quantify software reusability for quality product.
文摘Due to rapid development in software industry, it was necessary to reduce time and efforts in the software development process. Software Reusability is an important measure that can be applied to improve software development and software quality. Reusability reduces time, effort, errors, and hence the overall cost of the development process. Reusability prediction models are established in the early stage of the system development cycle to support an early reusability assessment. In Object-Oriented systems, Reusability of software components (classes) can be obtained by investigating its metrics values. Analyzing software metric values can help to avoid developing components from scratch. In this paper, we use Chidamber and Kemerer (CK) metrics suite in order to identify the reuse level of object-oriented classes. Self-Organizing Map (SOM) was used to cluster datasets of CK metrics values that were extracted from three different java-based systems. The goal was to find the relationship between CK metrics values and the reusability level of the class. The reusability level of the class was classified into three main categorizes (High Reusable, Medium Reusable and Low Reusable). The clustering was based on metrics threshold values that were used to achieve the experiments. The proposed methodology succeeds in classifying classes to their reusability level (High Reusable, Medium Reusable and Low Reusable). The experiments show how SOM can be applied on software CK metrics with different sizes of SOM grids to provide different levels of metrics details. The results show that Depth of Inheritance Tree (DIT) and Number of Children (NOC) metrics dominated the clustering process, so these two metrics were discarded from the experiments to achieve a successful clustering. The most efficient SOM topology [2 × 2] grid size is used to predict the reusability of classes.
文摘This paper analyzes the launch price of the launch vehicles, domestic and abroad, studies the status and trend of the low cost launch vehicles, and introduces two measures to reduce the cost by means of evolved and disruptive technologies, utilizing the concept of low cost manufacturing and operating modes as well. This paper also analyzes the launch strategies for small satellites such as piggyback, networking launch, and single launch with a small launch vehicle(SLV). Finally, the development trend of reusable launch vehicles is discussed as well as the development prospects for China's reusable launch vehicle.
基金financially supported by the National Natural Science Foundation of China(Nos.22178047 and 21878042)the Fundamental Research Funds for the Central Universities(No.DUT22LAB610)Liaoning province science and technology plan projects(No.2022JH2/101300233).
文摘Large-area and free-standing photonic crystal(PC)polymer films exhibit highly saturated iridescence and robust structural colors,making them promising for applications in the field of display,anti-counterfeiting,and camouflage.However,their practical utilization has been hindered by challenges in achieving both vivid coloration and reusability.Here,we design a sandwich-structured PC film that simultaneously addresses issues of color appearance and reusability by combining colloid evaporative self-assembly on porous substrate and knife coating of polymers.The unique“sandwich”structure,comprising a self-assembled PC intermediate layer and protective polymer encapsulation,demonstrates a great synergistic effect(“1+1>2”),including unprecedented color fastness stability(affordable for 100 times dye/wet fastness),bright iridescent color,and certain flexibility and reusability.In addition,by replacing the bottom polymer with a double-sided adhesive,a flexible PC sticker can be further obtained,broadening its range of applications to surfaces of different materials.This strategy opens a new avenue for constructing functionalized iridescent PC-polymer films.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.2021R1A2C1004131 and RS-2024-00406152)supported by the Institute of Information&Communications Technology Planning&Evaluation(IITP)-ITRC(Information Technology Research Center)grant funded by the Korea government(MSIT)(IITP-2025-RS-2023-00258971,20%,and RS-2023-00228994).
文摘The COVID-19 pandemic has exposed the limitations of traditional preventative measures and underscored the essential role of face masks in controlling virus transmission.More effective and recyclable facial masks using various materials have been developed.In this work,vertically aligned carbon nanotubes(VACNTs)are employed as effective facial mask filters,particularly aimed at preventing SARS-CoV-2 virus infection in preparation for future COVID-19 pandemics.This study assesses six critical aspects of facial masks:hydrophobicity,industrial viability,breathability,hyperthermal antiviral effect,toxicity,and reusability.The VACNT alone exhibits superhydrophobicity with a contact angle of 175.53◦,and an average of 142.7◦for a large area on spun-bonded polypropylene.VACNTs are processed using a roll-to-roll method,eliminating the need for adhesives.Due to the aligned tubes,VACNT filters demonstrate exceptional breathability and moisture ventilation compared to previously reported CNT and conventional filters.Hyperthermal tests of VACNT filters under sunlight confirm that up to 99.8%of the HCoV 229E virus denatures even in cold environments.The safety of using VACNTs is corroborated through histopathological evaluation and subcutaneous implantation tests,addressing concerns of respiratory and skin inflammation.VACNT masks efficiently transmit moisture and rapidly return to their initial dry state under sunlight maintaining their properties after 10000 bending cycles.In addition,the unique capability of VACNT filters to function as respiratory sensors,signaling dampness and facilitating reuse,is assessed,alongside their Joule heating effect.
基金supported by the National Key S&T Special Project(Grant No.2012ZX06901-022)
文摘It is well known that static seals are usually designed to be used once. In this paper, we discuss the reusability of a type of static seal called the spring energized metal C ring, which is required to be reused 4-5 times without maintenance during the lifetime of the pump. A theoretical analysis based on the nonlinear finite element method and an experimental investigation of the reusability of the C ring are carried out. The effects of the elastic modulus of the ring material, the ring wall thickness, the amount of assembly interference between the spring and the C ring, the operating temperature and the compression ratio are discussed. The parameter S, which denotes the reaction force difference percentage, is determined to measure the reusability of the C ring. The results show that the ring wall thickness plays an important role in the reusability. Although the normal force of a thick wall decreases after the ring is reused eight times, the value is still higher than the first normal force of a thin wall. In contrast, the elastic modulus of the material has the lowest impact. Here, a pre-compression ratio of 18.2% not only produces a larger first normal force but also leads to a smaller reduction in the normal force when the ring is reused. A simulated experiment is carried out to investigate the influence of the coating of the C ring on its reusability. The results show that when plastic deformation occurs on the contact surface, the contact state of the C ring coating becomes a major factor that affects the seal performance. Aging treatment at high temperatures （250℃） reduces gized metal C ring, which leads to the deterioration in the reusability the binding force of the silver coating on the spring ener of the ring.
基金funding agency in the public,commercial or not-for-profit sectors.
文摘Artificial neural networks(ANNs),a branch of artificial intelligence,has become a very interesting domain since the eighties when back-propagation(BP)learning algorithm for multilayer feed-forward architecture was introduced to solve nonlinear problems.It is used extensively to solve complex nonalgorithmic problems such as prediction,pattern recognition and clustering.However,in the context of a holistic study,there may be a need to integrate ANN with other models developed in various paradigms to solve a problem.In this paper,we suggest discrete event system specification(DEVS)be used as a model of computation(MoC)to make ANN models interoperable with other models(since all discrete event models can be expressed in DEVS,and continuous models can be approximated by DEVS).By combining ANN and DEVS,we can model the complex configuration of ANNs and express its internal workings.Therefore,we are extending the DEVS-based ANN proposed by Toma et al.[A new DEVS-based generic art-ficial neural network modeling approach,The 23rd European Modeling and Simulation Symp.(Simulation in Industry),Rome,Italy,2011]for comparing multiple configuration parameters and learning algorithms and also to do prediction.The DEVS models are described using the high level language for system specification(HiLLS),[Ma¨ıga et al.,A new approach to modeling dynamic structure systems,The 29th European Modeling and Simulation Symp.(Simulation in Industry),Leicester,United Kingdom,2015]a graphical modeling language for clarity.The developed platform is a tool to transform ANN models into DEVS computational models,making them more reusable and more interoperable in the context of larger multi-perspective modeling and simulation(MAS).
文摘The radiative heat flux of the plume from reusable rockets is a critical parameter during the launch and return processes.This paper proposes a method for calculating radiative heat flux with higher accuracy than previously reported for a recoverable nine-engine liquid-propellant rocket.Based on the Radiative Transfer Equation(RTE),this study employs the discrete transfer method to solve the transient RTE problem using physical properties to describe the problem while avoiding the need to directly solve mathematical equations.The proposed method can effectively determine the radiative heat flux of the flow field and is applicable to problems involving various geometries.Calculations reveal that during the ascent phase of the rocket,the radiative heat flux at the base of the vehicle reaches its maximum in the initial stages of the lift-off,reaching a maximum of~50 kW/m^(2),which is 2.24 times the maximum value during the return phase.During the deceleration stage of re-entry into the atmosphere,the maximum radiative heat flux recorded on the sidewall of the rocket is 29.1 kW/m^(2);the maximum heat flux on the bottom surface is approximately 22.3 kW/m^(2),accounting for 76.6%of that on the rocket's sidewall.This provides a basis for the thermal protection design of the rocket's bottom and walls as well as for the thermal management of cryogenic propellant tanks.Future research will involve ground engine testing and flight experiments to further validate the proposed model.
基金financially supported by the Key R&D Program of Shandong Province,China(2023CXGC010712).
文摘Herein,a reusable and portable surface-enhanced Raman spectroscopy(SERS)sandpaper was successfully synthesized for the sensitive detection of S-fenvalerate in foods.Commercial sandpapers were decorated with Ag@SiO2@Au nanoarrays via a liquid-liquid interface self-assembly method.The capacity of sandpaper to float directly on the cyclohexane-water interface allows nanoarrays to be formed directly on it,thereby minimizing stacking issues typically associated with nanoarray assemblies and significantly enhancing the sensitivity of S-fenvalerate detection.Moreover,the SERS sandpaper was reusable and portable due to its strong adhesion of the nanoarrays.Under optimized testing conditions,the developed SERS sandpaper method was capable of detecting S-fenvalerate,demonstrating a strong linear response within a concentration range of 10^(–7)–10^(3)μmol/L,with a limit of detection of 1.92×10^(−8)μmol/L.The analysis of spiked food samples containing S-fenvalerate using the developed SERS sandpaper afforded excellent recoveries(92.2%−109.7%).Additionally,the SERS sandpaper was successfully applied to quantify S-fenvalerate in real food samples,with results consistent with analyses conducted using gas chromatography.
基金a funded project under the 2024 Hibah Penelitian Produktivitas Guru Besar(Professor Research Productivity Grant)scheme at Jember University.
文摘This study demonstrates the valorization of macadamia nutshells,a lignocellulosic agricultural waste,as both a carbon source for amylase production and a support matrix for enzyme immobilization.Under optimized solid-state fermentation conditions,Aspergillus niger ICP2 synthesized amylase with a peak activity of 0.312 U/mL after 72 hours.A four-step purification process of the crude enzyme extract resulted in a 188.54-fold increase in specific activity,albeit with a final recovery yield of 0.0031%.In parallel,nutshells were carbonized at 600℃,700℃,and 800℃,then chemically activated with ZnCl_(2).The carbon derived at 700℃ exhibited superior physicochemical characteristics,including enhanced porosity and increased availability of functional groups,which enabled effective enzyme adsorption,improved catalytic performance,and enhanced reusability.Immobilized amylase on this support retained approximately 30% of its initial activity after five hydrolysis cycles,demonstrating moderate operational reusability and potential for repeated use in bioprocesses.In contrast,carbon materials from 600℃ and 800℃ showed lower stability and enzyme performance.These findings highlight the critical role of carbonization conditions in designing effective immobilization matrices and underscore the potential of macadamia nutshells as a renewable and sustainable resource for biocatalyst development.This“biowaste-to-biocatalyst”strategy exemplifies a circular bioeconomy model with implications for green chemistry,industrial biocatalysis,and environmental sustainability.
文摘Achieving vibration isolation,lightweight design,and reusability under impact remains a critical challenge for thin-walled structures.When the goat skull is subjected to impact,both the outer wall of the sinus and the internal bony struts deform simultaneously to absorb energy and protect intracranial tissues.Inspired by this mechanism,we designed the goat sinus-inspired bio mimetic(GSIB) structure by mimicking the outer wall of the sinus and the internal pillar-like support system.The structure consists of dual coupling beams,including a set of inclined cantilever beams representing the sinus outer wall and vertical support beams simulating the internal bony struts.The GSIB structure was fabricated using Selective Laser Sintering(SLS) 3D printing technology,and its mechanical properties were investigated through a combination of quasi-static compression tests,vibration tests,impact tests,and finite element simulations.Under compressive loading,the inclined cantilever beams buckle to introduce a negative stiffness effect,while the vertical supports enhance overall stiffness.Leveraging the coupling effect between these two components,the structure achieves a long-stroke constant-force response,thereby delivering superior performance in energy absorption and vibration isolation.Additionally,the special deformation mode of the GSIB structure enables it to be reused under impact conditions.It is noteworthy that,compared to the negative stiffness(NS) structure with the same dimensions for repeated buffering proposed in previous studies,the GSIB structure demonstrates an energy absorption capacity reaching 214.3% of that of the NS structure,a reduction in isolation frequency to 58.5%,and an impact acceleration that is only 66.31% of that of the NS structure.Additionally,the plateau stress of the proposed structure increases to 246.07% of that of the NS structure.This novel artificial structure provides a new design strategy for achieving superior energy absorption and impact resistance under repeated impact conditions.
基金supported by the National Natural Science Foundation of China(Nos.52303380,52025132,52273305,22205185,21621091,22021001,and 22121001)Fundamental Research Funds for the Central Universities(No.20720240041)+3 种基金the 111 Project(Nos.B17027 and B16029)the National Science Foundation of Fujian Province of China(No.2022J02059)the Science and Technology Projects of Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(No.RD2022070601)the New Cornerstone Science Foundation through the XPLORER PRIZE。
文摘Excessive Fe^(3+) ion concentrations in wastewater pose a long-standing threat to human health.Achieving low-cost,high-efficiency quantification of Fe^(3+) ion concentration in unknown solutions can guide environmental management decisions and optimize water treatment processes.In this study,by leveraging the rapid,real-time detection capabilities of nanopores and the specific chemical binding affinity of tannic acid to Fe^(3+),a linear relationship between the ion current and Fe^(3+) ion concentration was established.Utilizing this linear relationship,quantification of Fe^(3+) ion concentration in unknown solutions was achieved.Furthermore,ethylenediaminetetraacetic acid disodium salt was employed to displace Fe^(3+) from the nanopores,allowing them to be restored to their initial conditions and reused for Fe^(3+) ion quantification.The reusable bioinspired nanopores remain functional over 330 days of storage.This recycling capability and the long-term stability of the nanopores contribute to a significant reduction in costs.This study provides a strategy for the quantification of unknown Fe^(3+) concentration using nanopores,with potential applications in environmental assessment,health monitoring,and so forth.
基金supported by the National Key Research&Development Program of China(grant no.2022YFC3500503)the National Natural Science Foundation of China(grant nos.62227807,12374171,12004034,62402041)+2 种基金the Beijing Institute of Technology Research Fund Program for Young Scholars,Chinathe Fundamental Research Funds for the Central Universities(grant nos.2024CX06060)Beijing Youth Talent Lifting Project.
文摘Due to their high mechanical compliance and excellent biocompatibility,conductive hydrogels exhibit significant potential for applications in flexible electronics.However,as the demand for high sensitivity,superior mechanical properties,and strong adhesion performance continues to grow,many conventional fabrication methods remain complex and costly.Herein,we propose a simple and efficient strategy to construct an entangled network hydrogel through a liquid-metal-induced cross-linking reaction,hydrogel demonstrates outstanding properties,including exceptional stretchability(1643%),high tensile strength(366.54 kPa),toughness(350.2 kJ m^(−3)),and relatively low mechanical hysteresis.The hydrogel exhibits long-term stable reusable adhesion(104 kPa),enabling conformal and stable adhesion to human skin.This capability allows it to effectively capture high-quality epidermal electrophysiological signals with high signal-to-noise ratio(25.2 dB)and low impedance(310 ohms).Furthermore,by integrating advanced machine learning algorithms,achieving an attention classification accuracy of 91.38%,which will significantly impact fields like education,healthcare,and artificial intelligence.
文摘BACKGROUND Single-use duodenoscopes(SDs)were introduced to eliminate exogenous infection risks post-endoscopic retrograde cholangiopancreatography(ERCP).AIM To evaluate their efficacy and safety against reusable duodenoscopes(RDs).METHODS This was a single-center case control study.All consecutive patients undergoing ERCP using SD between 2020 and 2023 were enrolled.A similar number of patients undergoing ERCP using RD were randomly selected and enrolled.In case of ERCP failure using SD,operators switched to a RD if judged appropriate.The primary outcome was successful ERCP completion rates.The secondary outcomes were rate of difficult biliary cannulation,incidence of crossover from SD to RD,procedure related adverse events,30-day re-admission rate,and endoscopists'assessment of SD's performance.RESULTS A total of 133 patients were enrolled(n=53 for SD,n=80 for RD).Baseline characteristics and American Society for Gastrointestinal Endoscopy ERCP complexity grades were comparable between both groups.Successful ERCP completion rates were 88.7%for SD and 95%for RD(P=0.3).In cases of unsuccessful ERCP with SD,crossover to RD occurred in 3 out of 6 instances,with 2 subsequently succeeding with RD.Rates of adverse events and 30-day readmission were comparable:(1)13.2%vs 11.2%(P=0.19);and(2)15.4%vs 8.9%(P=0.25),respectively.Median overall endoscopists’satisfaction with SD was 8 out of 10.CONCLUSION The novel SDs demonstrated no difference in efficacy and safety compared to conventional RDs when used to perform a wide range of ERCPs.Nevertheless,further development and study of SDs’financial and environmental effectiveness is warranted.
基金co-supported by the National Natural Science Foundation of China(No.62103014)。
文摘An optimal feedback guidance law with disturbance rejection objective is proposed for endoatmospheric powered descent.This guidance law with an affine form is derived by solving a novel problem called Endoatmospheric Powered Descent Guidance with Disturbance Rejection(Endo-PDG-DR).The key idea of formulating the Endo-PDG-DR problem is dividing disturbances into two parts,modeled and unmodeled disturbances:the modeled disturbance is proactively exploited by augmenting it as a new state of a dynamics model;the unmodeled disturbance is reactively attenuated in terms of its effect on the guidance performance by adjoining a parameterized time-varying quadratic performance index in the proposed optimal guidance problem.A Pseudospectral Differential Dynamic Programming(PDDP)method is developed to solve the Endo-PDG-DR problem,and correspondingly a robust neighboring optimal state feedback law is obtained,which has two synergistic functionalities.One is adaptive optimal steering to accommodate the modeled disturbance,and the other is disturbance attenuation to compensate for the state perturbation effect induced by the unmodeled disturbance.Using the derived feedback guidance law,a disturbance rejection level is quantified,and is correspondingly optimized by designing a quadratic weighting parameter tuning law.The numerical computations of interest are performed within a pseudospectral setting,ensuring polynomial analytical solution,high computational efficiency,and reliable convergence.
