A data-driven digital-twin prognostics method for proton exchange membrane fuel cell remaining useful life prediction

Prognostics and health management of proton exchange membrane fuel cell (PEMFC) systems have driven increasing research attention in recent years as the durability of PEMFC stack remains as a technical barrier for its large-scale commercialization. To monitor the health state during PEMFC operation, digital twin (DT), as a smart manufacturing technique, is applied in this paper to establish an ensemble remaining useful life prediction system. A data-driven DT is constructed to integrate the physical knowledge of the system and a deep transfer learning model based on stacked denoising autoencoder is used to update the DT with online measurement. A case study with experimental PEMFC degradation data is presented where the proposed data-driven DT prognostics method has applied and reached a high prediction accuracy. Furthermore, the predicted results are proved to be less affected even with limited measurement data.     

Kinetic analysis of cellular internalization and expulsion of unstructured D-chirality cell penetrating peptides

Most cell penetrating peptides (CPPs) are unstructured and susceptible to proteolytic degradation. One alternative is to incorporate D-chirality amino acids into unstructured CPPs to allow for enhanced uptake and intracellular stability. This work investigates CPP internalization using a series of time, concentration, temperature, and energy dependent studies, resulting in a three-fold increase in uptake and 50-fold increase in stability of D-chirality peptides over L-chirality counterparts. CPP internalization occurred via a combination of direct penetration and endocytosis, with a percentage of internalized CPP expelling from cells in a time-dependent manner. Mechanistic studies identified that cells exported the intact internalized D-chirality CPPs via an exocytosis independent pathway, analogous to a direct penetration method out of the cells. These findings highlight the potential of a D-chirality CPP as bio-vector in therapeutic and biosensing applications, but also identify a new expulsion method suggesting a relationship between uptake kinetics, intracellular stability, and export kinetics.     

Prediction and optimization of electroplated Ni-based coating composition and thickness using central composite design and artificial neural network

Journal of Applied Electrochemistry - The choice of the electroplating conditions of Ni-based alloys has always been a serious research question. In this study, an artificial neural network based...     

Experimental analysis of fuel from fish processing industry waste in a diesel engine

In the present work, biofuel derived from industrial fish processing industry waste is used in diesel engines to study its suitability . Biofuel from industry fish waste is produced through catalytic cracking, and its quality has been improved through distillation. A single cylinder 4.5 kW at 1500 rpm was used to find the suitability of biofuel and undistilled biofuel in diesel engine. Experimental results show that the brake thermal efficiency of biofuel and undistilled biofuel is similar. Brake thermal efficiency for diesel, undistilled biofuel and biofuel is 29.98, 32.12 and 32.4%, respectively, at 80% load. Carbon monoxide, unburnt hydrocarbons, particulate matter and oxides of nitrogen emissions increase with undistilled biofuel compared to biofuel. There is a small reduction in carbon dioxide emission with undistilled biofuel compared to biofuel. Even though the cylinder pressure is high with undistilled biofuel, the intensity of premixed combustion is lower than distilled biofuel. The ignition delay and combustion duration increase with undistilled biofuel. Finally, it is concluded that the fuel derived from fish processing industry waste can be used as a fuel for diesel engine after distillation.     

A meta-heuristic approach to solve a JIT scheduling problem in hybrid flow shop

In this paper we address a hybrid flow shop scheduling problem considering the minimization of the sum of the total earliness and tardiness penalties. This problem is proven to be NP-hard, and consequently the development of heuristic and meta-heuristic approaches to solve it is well justified. So, we propose an ant colony optimization method to deal with this problem. Our proposed method has several features, including some heuristics that specifically take into account both earliness and tardiness penalties to compute the heuristic information values. The performance of our algorithm is tested by numerical experiments on a large number of randomly generated problems. A comparison with solutions performance obtained by some constructive heuristics is presented. The results show that the proposed approach performs well for this problem.     

Hybrid micro electrostatic actuator

A hybrid micro-electrostatic actuator is presented. The actuator integrates a vertical comb driving (VCD) unit and a parallel-plate driving (PPD) unit. The hybrid actuator is fabricated using a one structural layer microfabrication process, i.e., MetalMUMPs instead of a two-layer microfabrication process needed for traditional vertical comb-drive actuators by taking advantage of the residual stress gradient in the MetalMUMPs nickel layer, which raises the moving parts of the actuator above the substrate after release. The hybrid actuator significantly simplifies the fabrication process for vertical comb-drive actuators, i.e., turning a process requiring two structural layers into a process requiring only one structural layer and thus avoids any misalignment between the two layers. The hybrid actuator can generate larger force and then a larger displacement than the actuator having only the VCD with the same area since no extra space is needed for the PPD unit which uses the moving electrode existing in the VCD unit and a fixed electrode under the VCD unit. The VCD and PPD units in the hybrid actuator are subject to the same driving voltage and work together to pull the moving parts of the actuator downward. A model is established for the hybrid actuator to analyze its displacement. The analytical results show that displacement of the moving part of the hybrid actuator is about half of the gap between the electrodes of the PPD unit. Prototypes are fabricated and tested. With a driving voltage of 150 V, the hybrid actuator achieved a measured displacement of 6.48 µm.     

Steam reforming of methanol over ruthenium impregnated ceria,alumina and ceria–alumina catalysts

The wet impregnation method was used to prepare different ruthenium promoted Ce–Al catalysts. These catalysts were used in the steam reforming of methanol reaction (SRM). The effects of the reaction temperature (200–400 C) and the catalyst composition were studied for optimization reasons. The steam to methanol molar ratio was kept constant (S/M = 2). The promotion of cerium/aluminum oxides with Ru enhanced their catalytic activity. The catalytic test results showed that the Ru/Ce combination was the most beneficial. The synergy between Ru and cerium oxide led to the formation of active sites with excellent redox properties. For high active phase content, the 5 RuCe catalyst exhibited the highest hydrogen production amount with no CO formation. This catalyst was kept under stream for 5 days at 400 C, and no significant deactivation was observed. Copyright © 2016 John Wiley & Sons, Ltd.     

Deposition of hybrid 3-GPTMS's film on AA2024-T3: Dependence of film morphology and protectiveness performance on coating conditions

This paper describes the elaboration of 3-glycidoxypropyltrimethoxysilane (3-GPTMS) films onto AA2024-T3 aluminum alloy for corrosion protection.The dependence of sol–gel morphology on both precipitation under cathodic polarization and nitrate incorporation was investigated via scanning electron microscopy (SEM).Once added into silanization solution, sodium nitrate promoted the reaction of silane condensation and enhanced the film compactness.Electrochemical impedance spectroscopy results (EIS) indicated that doping silane film with NaNO₃ ameliorated its barrier property and protectiveness. Silane films applied onto AA2024-T3 surface by using potentiostatic method, exhibited obviously higher corrosion resistance than those obtained by conventional “dip-coating” method. The resistance of coating is accentuated when not very negative potential was applied.     

Bioactive and Physicochemical Properties of Persimmon as Affected by Drying Methods

In this study, the effects of three different drying methods (freeze drying, oven drying, and vacuum oven drying) on bioactive (total phenolics, total flavonoids, condensed tannin and total hydrolyzable tannin contents, antiradical activity, and antidiabetic activity) and some physicochemical (dry matter, ash, water activity (a _w ), color, protein, hydroxymethylfurfural, glucose and fructose content) properties of persimmon fruit were investigated. Simplex lattice mixture design methodology was applied to determine the best solvent mixture for the extraction of phenolics from the samples. It was found that the mixture of acetone:water at the ratio of 50:50 % (v/v) was the best solvent mixture for the extraction. The persimmon powder sample obtained from freeze drying showed significantly (p <0.05) higher bioactivity values than oven- and vacuum-oven-dried samples. Antiradical activity changed significantly depending on the drying method employed and it was superior in freeze-dried samples than that of the other drying methods.