Knowledge of the structural response of bridges is extremely important for highway asset management and bridge structural health monitoring. Instrumenting every bridge in a road network and ...maintaining the monitoring instrumentation over decades of service can be financially infeasible. Mechanical intuition suggests a significant relationship exists between responses of two sets of bridges reasonably similar in design exposed to an identical load. This study explores the use of data-driven models to forecast the response of one bridge to a given truck load using the response of another bridge to the same loading profile. By deploying a modern monitoring system in multiple bridges in the same highway corridor integrated in a cyber-physical systems (CPS) framework, and utilizing advanced computer vision algorithms, the authors have gathered a unique dataset consisting of pairs of bridge responses to the same truck load from live traffic moving across a 32.2 km (20 miles) stretch of the I-275 highway in southeast Michigan. Signal processing techniques have been employed to isolate the response of the bridges to a single truck load in a time series of recorded responses. Then, a deep-learning-based time series forecasting framework using the encoder-decoder architecture with gated recurrent unit (GRU) and long short-term memory (LSTM) cells has been used for bridge response forecasting. Baseline models based on linear time series models are also developed to which the deep-learning forecasting models can be compared. After training the models, it is observed that deep-learning-based models can accurately forecast the response of one bridge using the response of another and reduce the forecasting root-mean-squared error (RMSE) by at least 20% relative to baseline linear models. The forecasting capabilities of the encoder-decoder architecture proposed herein outperform traditional approaches to response forecasting. Trained versions of the encoder-decoder forecasting model can be used to provide reliable estimates of bridge response using a single instrumented bridge in a corridor, thereby enhancing the value of data from instrumented bridges for asset management of bridge networks.
With increasing awareness on environmental protection and food safety, the development of biodegradable antimicrobial packaging materials has been paid growing emphasis. In this work, ...starch/poly(butylene adipate-co-terephthalate)/ε-polylysine hydrochloride films were prepared by extrusion blowing, and five commercial organically modified nanomontmorillonites (OMMT, including DK1, DK2, DK3, DK4, and DK5) were used as reinforcing agents. Intercalated structures were formed in the nanocomposite films, especially for those with DK3 and DK4 owing to their higher hydrophobicity and larger interlayer spacing. Adding OMMT weakened hydrogen bonds and the gelatinization/plasticization degree of starch. Morphology analysis revealed that the agglomeration of OMMT occurred in the films, but the film containing DK3 still showed a relatively homogeneous microstructure. Loading OMMT enhanced the strength, deformation resistance, thermal stability, surface hydrophobicity, but decreased barrier properties and water sensitivity of the films. Antimicrobial activity showed that the OMMT and ε-polylysine hydrochloride possessed a synergistic effect against Staphylococcus aureus and Escherichia coli. The maximum inhibition rate was observed in that with DK4, approaching 100 %. Findings supported the application of commercial OMMT in manufacturing biodegradable antimicrobial blown films.
Display omitted
•Starch/PBAT/ε-polylysine hydrochloride antimicrobial blown films were developed.•Different organically modified nanomontmorillonites (OMMT) were used as reinforcer.•Higher hydrophobicity and interlayer spacing contributed the exfoliation of OMMT.•Thermal stability, mechanical strength, and water resistance were enhanced by OMMT.•OMMT and ε-polylysine hydrochloride showed synergistic antimicrobial effects.
For end-stage hepatic alveolar echinococcosis, insufficient guidance is available regarding surgical treatment, especially for ex vivo liver resection combined with autotransplantation. The ...indications for this complex surgery require further discussion.
We reviewed 50 cases of patients who underwent ex vivo liver resection combined with autotransplantation from January 2014 to February 2018. A newly developed classification was used to describe vascular infiltration in all patients, who were divided into four groups based on anatomic lesion features and surgical patterns. The surgical planning for ex vivo liver resection combined with autotransplantation is then thoroughly discussed according to the gathered information.
In all patients, the length of the operation and the anhepatic phase were 735 minutes (range, 540-1,170 minutes) and 309 minutes (range, 122-480 minutes), respectively. The median remnant liver volume–to–standard liver volume ratio was 0.58 (range, 0.32-1.11). The rate of complications classified as Clavien-Dindo grade III or higher was 22% (11/50). A total of 3 postoperative deaths occurred. We identified 4 types with distinguished lesion anatomic features. Type I patients required more frequent unconventional reconstruction of the portal vein and bile duct than the other patients. Of the 6 type IV patients, 4 required modification of the surgical protocol according to intraoperative findings.
Vascular infiltration-based classification could improve the anatomic comprehension and, thus, facilitate surgical planning for ex vivo liver resection combined with autotransplantation. Through cautious evaluation of operability, liver function, and residual liver volume, together with delicate operative techniques and careful postoperative management, ex vivo liver resection combined with autotransplantation can achieve good results in the treatment of end-stage hepatic alveolar echinococcosis.
Secondary Budd-Chiari syndrome (BCS) occurs due to a blockage in the liver caused by invasion or compression by a large lesion. Conventional treatments for BCS do not solve practical problems, ...wherease liver transplantation has been only applied as a last-resort therapy and as the only opportunity for a radical cure. We explored the feasibility of applying ex vivo liver resection and autotransplantation (ELRA) for the new indications of treating patients with end-stage hepatic alveolar echinococcosis (HAE). Our center has firstly proposed the idea and successfully treated the 49 patients with HAE. This article for the first time reports the application of ELRA in treating patients with BCS secondary to HAE.
According to the degree of lesion invasion and surgical options, 11 patients were divided into 4 types. These 11 patients had large lesions that invaded the second and third hilum of the caudate lobe and involved the confluence of the hepatic vein and the inferior vena cava, suprahepatic vena cava, or at least 2 hepatic veins and led to secondary BCS. The aim of the present work was to report 11 patients with life-threatening diseases who underwent ELRA (ex vivo liver resection and autotransplantation) for secondary BCS, to propose a classification system for secondary BCS, and to suggest that secondary BCS is an indication for ELRA.
Eleven patients successfully underwent ELRA without intraoperative mortality. The median autograft weight was 690 g (440-950 g); operative time was 12.5 hours (9.4-16.5 hours); Postoperative hospital stay was 15 days (7-21 days). Clavien-Dindo grade IIIa or higher postoperative complications occurred in only 5 patients.
This article for the first time reports the application of ELRA in treating patients with BCS secondary to HAE, not only provides new ideas for alternative treatments of secondary BCS, but also provides a classification system for secondary BCS. This article describes the technical process of outflow tract reconstruction and the experience for expanding the indications for ELRA. Our study demonstrated that ELRA is well feasible for treatment of BCS secondary to advanced HAE.
Exploring the key influencing factors (KIFs) of Urban Low-Carbon Innovation (ULCI) from urban characteristics is essential for devising customized promotion strategies. However, existing studies are ...hampered by methodological limitations that lead to an inability to effectively discern KIFs among urban characteristics or unravel complex, non-linear relationships, and interaction effects. To address these gaps, this paper adopts a synthetic approach based on interpretable Machine Learning (ML). Firstly, the influencing factors are identified through the Delphi method and a systematic literature review. Subsequently, three single AI models (KNN, SVR, and CART) and three ensemble models (RF, XGBoost, and LBGM) are employed to fit the data. Finally, the SHapley Additive exPlanations (SHAP) algorithm is integrated to identify the KIFs and disentangle their impact effects. The findings indicate that (1) 41 influencing factors are identified, from which 10 KIFs, such as Expenditure on Research, Carbon Emissions, Local General Budgetary Revenue, and Education Expenditure, are determined, (2) the developed interpretable ML model tailored for ULCI’s KIFs analysis demonstrates high precision and effectively capturing non-linear relationships (R2 = 0.841, RMSE = 0.591, MAE = 0.463), and (3) the global impact, interactive effects, and individual sample impact of the KIFs are explained, and two categories of KIFs dominated by positive and negative influences are revealed respectively. Results of the KIFs identification can provide policy-makers with insight for designing ULCI enhancement paths and consequently promote emission mitigation in China.
•41 influencing factors of ULCI is identified from urban characteristics.•An interpretable ML model is developed to quantitatively explore KIFs.•10 KIFs are determined and the comprehensive impact, interactive effects, and individual sample impact of the them are explained.
•Magnetofluorescent GdN@CQDs/GP nanoparticles are synthesized by a chemical crosslinking reactions.•The drug delivery system of GdN@CQDs/GP-DOX are triggered by NIR light and pH dual-stimuli.•The ...GdN@CQDs/GP-DOX can effectively eliminate tumors through chemo-photothermal synergistic therapeutic effect.
Carbon dots could be extended in biological applications for drug delivery and photothermal therapeutics due to their ability to improving therapeutic effect and reducing side effects. Here, we use doxorubicin (DOX) as the model drug, the amino and carboxyl coated magnetofluorescent carbon quantum dots (GdN@CQDs) as a carrier, Genipin (GP) as cross-linking agent to design and prepare a multifunctional drug delivery system triggered by near-infrared (NIR) light and pH dual-stimuli. The cytotoxicity of the nanoparticles has been examined by MTT assay. The fluorescent GdN@CQDs/GP serves as both a controllable drug release gatekeeper and a fluorescent probe for the visualization of the drug delivery process. In vitro and in vivo experiments showed that this platform can deliver anti-cancer drugs to cells, releasing them intracellular upon NIR irradiation, and effectively eliminate tumors through chemo-photothermal synergistic therapeutic effect.
Sodium and potassium ions energy storage systems with low cost and high energy/power densities have recently drawn increasing interest as promising candidates for grid-level applications, while the ...lack of suitable anode materials with fast ion diffusion kinetics highly hinders their development. Herein, we develop a nanoscale confined in situ oxidation polymerization process followed by a conventional carbonization treatment to generate phosphorus and nitrogen dual-doped hollow carbon spheres (PNHCS), which can realize superior sodium and potassium ion storage performance. Importantly, the density functional theory calculation and combined characterizations, e.g., in situ Raman spectroscopy and ex situ X-ray photoelectron spectroscopy, decipher that the P/N doping can enhance the electronic transfer dynamics and ion adsorption capability, which are responsible for enhanced electrochemical performance. Inspiringly, the practicability of the PNHCS anode is demonstrated by assembling the potassium ion hybrid capacitors (KIHCs), where the prominent energy density is 178.80 Wh kg–1 at a power density of 197.65 W kg–1, with excellent cycling stability, can be achieved. This work not only promotes the development of efficient anode material for sodium/potassium ion storage devices but also deciphers the embedded ion storage mechanism.
Sodium humate was oxidized with nitric acid to obtain fulvic acid (FA), which was further quaternized to obtain quaternary fulvic acid (QFA). QFA-intercalated saponite (QFA-saponite) was prepared ...ultrasonically. Thermoplastic poly(lactic acid) (PLA)/quaternary fulvic acid-intercalated saponite nanocomposites were prepared by melt intercalation technique. The morphology and dispersion of QFA-saponite were investigated by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Mechanical properties, thermal stability and crystallization behavior of PLA/QFA-saponite nanocomposites were also tested. Results showed a predominantly flocculated structure and partially intercalated morphology for QFA-saponite. Mechanical testing and thermogravimetric analysis showed that the tensile strength, impact properties, and thermostability of PLA/QFA-saponite nanocomposites improved significantly compared to pure PLA. Differential scanning calorimetry results showed that crystallinity of PLA increased from 22.5 to 68.3 % on addition of QFA-saponite. Polarized optical microscopy showed QFA-saponite as a nucleating agent for PLA that enhanced its crystallization rate. Rotational rheological behaviors of PLA/QFA-saponite nanocomposites demonstrated that incorporation of QFA-saponite increased rigidity of the network structure in PLA matrix.
The effects of carbon monoxide (CO) poisoning and hydrogen dilution are investigated for a series of simulated reformate gases. A simple mathematical model with an internal air bleed term is proposed ...to understand the interaction between CO poisoning, hydrogen dilution, and the internal air bleed (IAB). According to the steady-state modeling results, the presence of nitrogen can be considered as a diluting agent for a relatively dilute H2–N2 mixture. For a CO–H2–N2 mixture, hydrogen dilution and CO poisoning “magnify” each other in their combined effect on the surface coverage of hydrogen. The beneficial effect of IAB was found to be affected by the competitive adsorption between CO and hydrogen. The steady-state surface coverage of CO is influenced by the adsorption and desorption of CO, the interaction between CO and the electro-oxidation of hydrogen, the interaction between IAB/hydrogen dilution/CO, the interaction between IAB/CO. However, the steady-state surface coverage of CO is largely determined by its own adsorption and desorption properties. Analytical solutions are also derived from the proposed mode for the transient surface coverage of hydrogen and CO. The mathematical treatment has been proved extremely effective for the understanding of the steady-state and transient behavior of the CO–H2 and CO–H2–N2 mixtures.
•The interaction between CO poisoning and hydrogen dilution is examined.•The effect of CO poisoning and H2 dilution on the internal air bleed is also investigated.•An analytical solution is first acquired for CO and H2 with the proposed model.
The microstructures and mechanical properties of Ti–Nb–V–Mo quaternary microalloyed high strength fire-resistant steel are investigated under different experimental conditions. The results show that ...the fire-resistant steel with high strength (ultimate tensile strength (UTS), 746 MPa; yield strength (YS), 597 MPa) and a low yield ratio (YS/UTS, 0.80) is successfully developed by rapid cooling combined with a low final cooling temperature. The microalloyed high strength fire-resistant steel tempered at 600 °C × 15 min and 600 °C × 180 min exhibit yield strength of 440 and 419 MPa, which values significantly exceed two-thirds of the specified yield strength at room temperature (i.e., 307 MPa) for the Q460 (YS ≥ 460 MPa) fire-resistant steel. The mechanical properties at room temperature and 600 °C even meet the requirements for the Q550 fire-resistant steel. The ferritic grain boundaries in the experimental steel tempered for 180 min at 600 °C show excellent stability. The analysis indicates that solid-solution strengthening and precipitation strengthening are important in improving the strength of the studied fire-resistant steel at room temperature and 600 °C, respectively. M(C, N) (M = Nb, V, Ti, and Mo) and M3C (M = Fe, Cr, Mn, and Mo) particles in small quantities are found in the matrix of the as-rolled sample. However, after reheating and tempering at 600 °C, large amounts of M(C, N) (mainly MC) and M3C particles precipitate. With an increasing in tempering time, the amount of nanoscale MC precipitate increases; especially, the amount of the MC particles size smaller than 10 nm, and the mass fraction of Nb, V, and Mo in the MC precipitate also increases, which is consistent with the equilibrium thermodynamic calculation results. This enhancement of the precipitation strengthening of secondary phase particles compensates for strength loss attributing to a decrease in shear elastic modulus and solid solution strengthening at 600 °C.
PDF
