221 research outputs found
sj-docx-1-tej-10.1177_20417314221125310 – Supplemental material for Expanding tubular microvessels on stiff substrates with endothelial cells and pericytes from the same adult tissue
No full textSupplemental material, sj-docx-1-tej-10.1177_20417314221125310 for Expanding tubular microvessels on stiff substrates with endothelial cells and pericytes from the same adult tissue by Xiuyue Song, Yali Yu, Yu Leng, Lei Ma, Jie Mu, Zihan Wang, Yalan Xu, Hai Zhu, Xuefeng Qiu, Peifeng Li, Jing Li and Dong Wang in Journal of Tissue Engineering</p
A Portrait of the Plagiarist as a Literary Theme in Tahsin Yucel's Yalan
No full textIn his Yalan (The Lie) Tahsin Yucel interrogates the theme of the lie as an undeniable sign of cultural globalization. As he does so, he exposes the falseness of the world and the identity of the liar that appears in not only university life but also modern media. During this interrogation, the author largely uses data from semiotics, which is also his field of research. He thus establishes the structure of his novel on the binary opposition, to be/to appear. This article aims to study the portrait of the plagiarist by employing certain theoretical definitions provided by psychology and to identify the main causes underlying plagiarism, which is a major theme within the context of the novel
Online State and Parameter Estimation for Lithium-ion Batteries Based on a Reduced-order Electrochemical Life Model
No full textInaccurate estimation of the state-of-charge (SOC) and the state-of-health (SOH) may lead to safety issues. Currently, estimations of SOC and SOH that based on electric equivalent circuit models (ECMs) have been widely applied. ECMs consist of electrical elements, which do not represent electrochemical behaviors, so they lack the ability of long-term prediction of battery lives. Alternatively, an electrochemical-based reduced-order model (ROM) can predict internal states, such as concentrations and potentials, which are directly related to the SOC. Moreover, degradation mechanisms can be modeled and integrated into the ROM to predict change aging-related parameters such as loss of lithium ions, loss of active materials, consumption of the electrolyte solvent and increase of internal resistances, which are related to the SOH.
In this work, we propose an SOC and SOH estimator in conjunction with the beginning-of-life (BOL) and aging parameter estimation method based on a ROM. At first, a procedure for automatic estimation of parameters of a lithium-ion battery at the BOL is developed, where a two-step sensitivity analysis is designed to group the parameters and divide them by the best SOC window. Then, the genetic algorithm is applied to minimize a multi-objective function that is the mean square error of voltage for each SOC window.
Based on the ROM with accurately estimated parameters, an SOC estimation algorithm is developed using an adaptive square-root sigma-point Kalman filter (ASR-SPKF) with equality state constraints. Equality state constraints derived from the principle of charge conservation are introduced to improve the accuracy of both anode and cathode SOC estimations. Because of its fast convergence speed, the cathode SOC is used to represent the bulk SOC. Approaches used to adaptively update the covariance matrices of the filter based on the covariance matching method are also incorporated. As a result, the covariance matrix of process noise is adjusted automatically. Comparative studies of three nonlinear filters concerning estimation accuracy, error bounds, recovery time from an initial offset, and computational time reveal that the ASR-SPKF has the most outstanding performance.
Finally, an online estimator for SOH and aging parameters is developed using a high-fidelity, reduced-order physics-based life model, where a pseudo-two-dimensional model coupled with degradation model of two types of side reactions—solid electrolyte interphase (SEI) layer formation and lithium plating—is used for the negative electrode, and a single particle model is used for the positive electrode to increase computational efficiency. A control-oriented incremental aging model is developed with the employment of a particle filter, from which the SOH and aging parameters are continuously monitored from real-time current and terminal voltage measurements. Finally, the developed method is tested in a battery-in-the-loop test station with a large format, 42 Ah, lithium-ion battery with Li(NiMnCo)O2/Carbon electrode chemistry
Automatic Estimation of Parameters of a Reduced Order Electrochemical Model for Lithium-Ion Batteries at the Beginning-of-Life
No full text
An Improved Immersed Boundary Method for Simulating Flow Hydrodynamics in Streams with Complex Terrains
No full textThree-dimensional (3D) computational fluid dynamic (CFD) simulations have gained substantial popularity in recent years for stream flow modelling. The complex terrain in streams is usually represented by a 3D mesh conforming to the terrain geometry. Such terrain-conforming meshes are time-consuming to generate. In this work, an immersed boundary method is developed in an existing terrain-conforming CFD model named U2RANS as an alternative, in which terrains are represented implicitly in the Cartesian background mesh. An improved two-layer wall function is proposed in the framework of the k-ε turbulence model, with the aim of producing accurate and smooth wall shear stress distribution and paving the way for future model development on sediment transport and scour modeling. The improvement overcomes the inherent discontinuity and nonlinearity of the two-layer velocity profile, which causes error in the estimation of shear velocity. The new algorithm utilizes a distance control on the image point in immersed boundary method and a modification of velocity prediction in the laminar layer. The improved immersed boundary method is tested with 1D, 2D, and 3D cases, and comparisons with flume experiments show promising results
Development and Validation of a Reduced Order Model Incorporating a Semi-Empirical Degradation Model for Pouch Type LiFePO<sub>4</sub>/Graphite Cells
No full textFinancial and SWOT Analysis of New Energy Vehicle Companies-Take Company X as an Example
No full textIn 2021, Company X and Huawei joint business deep cross-border integration, the official launch of Smart SF5 model, into the new energy vehicle enterprise market. In order to understand the development status of the Company X after its strategic transformation, the author first analyzed the company's internal strengths and weaknesses, external opportunities and threats through SWOT analysis, and built a strategic matrix model on this basis, and then combined with the financial statements of the past five years for further analysis. The study showed that the overall expenses during the period have increased, and the operating profit has continued to decrease. After the transformation, the market pressure of company has intensified. In order to help Company X alleviate the operating pressure and improve its business situation, the author finally provided development suggestions for Company X based on the value chain perspective, which provided experience for similar vehicle enterprises to learn from
- …
