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Currently, the numerical modeling methods used to characterize the thermal runaway and propagation mechanisms in NCM811 pouch batteries still face numerous challenges. This is primarily due to the uncertainties in thermal runaway reactions and the immense computational demands encountered when modeling begins at the granular level of the cell. To address this issue, this study designed a series of experiments for an NCM811 pouch battery. By employing experimental data, reasonable assumptions were made regarding the combined effects of solid-state thermal conduction, electrochemical heating, and fluid-solid heat transfer through gas jet streams. A simplified thermal runaway mathematical modeling method based on experimental data was proposed, effectively tackling the problem. This framework was then applied to thermal runaway experiments on a single NCM811 battery used in this study, providing essential input parameters for three-dimensional numerical modeling of modules composed of multiple batteries in multiphysics simulation software. The simulation results derived from the proposed method were in good agreement with experimental data. This study can characterize the thermal runaway and thermal propagation characteristics of battery modules using single-cell thermal runaway experiments. Moreover, the proposed modeling approach not only predicted the experimental outcomes of the NCM811 pouch battery with reasonable accuracy but also provided smoother data, elucidating the highly fluctuating trends observed in experimental data. This method also offers guidance for designing fire prevention and smoke exhaust systems for battery packs. This study presents a novel approach for the mathematical modeling of thermal runaway and thermal propagation in battery modules using NCM811 pouch batteries, contributing to the ongoing development of lithium-ion battery module design.

In this study, based on the liquid cooling method, a confluence channel structure is proposed, and the heat generation model in the discharge process of three-dimensional battery module is established. The effects of channel structure, inlet mass flowrate, and coolant flow direction on the heat generation of the battery module were studied by control variable method. Simulation results show that the confluence channel structure (e) shows good cooling effect on the battery temperature when controlling the 5 C discharge of the battery module. In addition, compared with the straight channel under the same working condition. In the discharge process of battery module, average temperature amplitude in battery module decreased by 17.3%, the inlet and outlet pressure is reduced by 16.47%, and the maximum temperature amplitude is reduced by 20.3%. Effectively improve temperature uniformity and reduce pressure drop. The problem of uneven temperature distribution caused by uneven velocity distribution of coolant in traditional straight channel is improved. At the same time, the design of the confluence structure accelerates the heat transfer of the channel plate and provides a new idea for the design of the cooling channel.

Solid propellant fires, characterized by uncontrolled combustion behaviors, are a common occurrence in industries that utilize solid propellants and can lead to significant consequences. However, there has been a lack of comprehensive studies on modeling and simulating the flame characteristics of NEPE solid propellant fires. This research aims to investigate the flame behaviors of large NEPE solid propellants at different altitudes using computational fluid dynamics (CFD). The flame's shape and temperature were examined based on experimental data under atmospheric conditions to validate the numerical model. The findings reveal that the simulated flame temperature slightly surpasses the experimental values, while the simulated flame length and width align well with the experimental measurements. Moreover, increasing altitudes result in shorter flame lengths and lower combustion temperatures. Furthermore, the study scrutinizes the influence of turbulence models on the flame behavior of NEPE propellant fires.

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4-Methylenepiperidine hydrochloride 1 is a key intermediate for synthesis of the novel antifungal drug efinaconazole 2. In this work, a simple and robust process has been developed to synthesize 4-methylenepiperidine hydrochloride 1, with a high overall yield of 99.1% at a high purity of 99.7% in a large-scale. Moreover, this synthetic process avoided the uses of organolithium reagent and column chromatography process which are not desirable for industrial production.

Fog-cloud computing is a promising computing paradigm for processing and storing massive data produced by Internet of Things (IoT) devices. Considering that the fog computing nodes are distributed, heterogeneous and have limited resources, it is not possible to deploy all the services belonging to IoT applications on the fog environment. Therefore, an efficient and autonomous mechanism is needed to map IoT services on the fog environment. The problem becomes more complicated when the various requirements of services including response time and cost are considered. With this motivation, we introduce a mixed-integer linear programming model to address the Fog Service Placement (FSP) problem in fog-cloud computing environments. This model is formulated as a multi-objective model with the aim of minimizing deadline violation, resource loss and service cost, and maximizing resource usage. Meanwhile, we propose an Elitism-based Genetic Algorithm to solve the FSP problem developed with a Shared Parallel Architecture (EGASPE). Our algorithm considers the efficient distribution of resources under certain Quality of Service (QoS) requirements and seeks a balance between exploration and exploitation. Also, EGASPE can save more resources for future requests by considering the deadline of IoT services over time. Extensive experiments have been performed to evaluate the performance of EGASPE on a synthetic fog environment. The obtained results show the effectiveness of EGASPE up to 6.5% on average compared to state-of-the-art algorithms.

Renewable energy sources, especially, solar-hydrogen, as an alternative system, play an important role in providing the required demand and decarbonization in green buildings. This study presents a modeling framework and optimal design of a grid-independent renewable energy sources scheme for a green building equipped solar and hydrogen storage. The solar-hydrogen energy system includes the supply of hydrogen as the required fuel to supply the energy of the fuel cell, as a backup system, to provide the programmed power. The objective of this research is to minimize system cost and maximize reliability under appropriate technical and economic constraints. For this purpose, an improved particle swarm optimization algorithm is presented. A case study is used for optimal synergy between photovoltaic panels and fuel cells and investigates its performance over a one-year period. To validate the results, the results obtained from the proposed algorithm have been compared with the results of the original algorithm. The effects of eight scenarios based on different reliability on the optimal design results of solar-hydrogen energy system have been compared and analyzed. The results indicate that the seasonal storage with different reliability scenarios has a great effect on hybrid system steady output and reliability. Also indicate that the proposed method has achieved 0.45 % better results and converged 15 % faster compared to the original algorithm. Moreover, the proposed algorithm is able to achieve a better solution in different high and medium reliability in design of the grid-independent energy system.

Dimensionality-reduction methods have been widely used to study the free energy landscapes and low-free-energy pathways of molecular systems. It was shown that the nonlinear dimensionality-reduction methods gave better embedding results than the linear methods, such as principal component analysis, in some simple systems. In this study, we have evaluated several nonlinear methods, locally linear embedding, Isomap, and diffusion maps, as well as principal component analysis from the equilibrium folding/unfolding trajectory of the second β-hairpin of the B1 domain of streptococcal protein G. The CHARMM parm19 polar hydrogen potential function was used. A series of criteria which reflects different aspects of the embedding qualities was employed in the evaluation. Our results show that principal component analysis is not worse than the nonlinear ones on this complex system. There is no clear winner in all aspects of the evaluation. Each dimensionality-reduction method has its limitations in a certain aspect. We emphasize that a fair, informative assessment of an embedding result requires a combination of multiple evaluation criteria rather than any single one. Caution should be used when dimensionality-reduction methods are employed, especially when only a few of the top embedding dimensions are used to describe the free energy landscape.

Abstract: This paper presents a new class AB transmitter with a low supply voltage/ground bouncing sensitivity for 10 Gb/s serial links. The low sensitivity of the output current to supply voltage fluctuation and ground bouncing is achieved by operating the system in a rail-to-rail swing mode. High data rates are obtained by multiplexing at low-impedance nodes and inductive shunt peaking with active inductors. The fully differential configuration and bipolar signaling of the transmitter minimize the effect of both common-mode disturbances and electro-magnetic interferences exerted from channels to neighboring devices. The class AB operation of the transmitter minimizes its static power consumption. The proposed transmitter is implemented in a 1.2 V 0.13μm CMOS technology and analyzed using Spectre from Cadence Design Systems with BSIM3v3 device models. Both pre and post-layout simulation results demonstrate that the transmitter conveys a sufficiently large differential output current that is insensitive to supply voltage fluctuation and ground bouncing at 10 Gb/s.

Abstract: This paper considers a simple step-stress accelerated life test model under progressive Type-I hybrid censoring scheme. The progressive Type-I hybrid censoring scheme and statistical method in synthetic accelerated stresses are provided so as to decrease the lifetime and reduce the test cost. An exponentially distributed life of test units and a cumulative exposure model are assumed. The maximum likelihood estimates of the model parameters are obtained using a pivotal quantity. Two useful lemmas and a theorem are given to construct the approximate confidence intervals for the model parameters. Finally, simulation results are provided to assess the method of inference developed in this article. The simulation results show that the method does improve for large sample size. [Copyright &y& Elsevier]