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The Third-Order Viscoelastic Acoustic Model Enables an Ice-Detection System for a Smart Deicing of Wind-Turbine Blade Shells

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Journal of Applied Mathematics and Physics 2016年第10期4卷 1949-1976页

作者： eugen mamontov Viktor Berbyuk Versati AB Askim Sweden Division of Dynamics Department of Applied Mechanics Chalmers University of Technology Gothenburg Sweden

The present work is based on the third-order partial differential equation (PDE) of acoustics of viscoelastic solids for the quasi-equilibrium (QE) component of the average normal stress. This PDE includes the stress-relaxation time (SRT) for the material and is applicable at any value of the SRT. The notion of a smart deicing system (SDS) for blade shells (BSs) of a wind turbine is specified. The work considers the stress in a BS as the one caused by the operational load on the BS. The work develops key design issues of a prospective ice-detection system (IDS) able to supply an array of the heating elements of an SDS with the element-individual spatiotemporal data and procedures for identification of the material parameters of atmospheric-ice (AI) layer accreted on the outer surfaces of the BSs. Both the SDS and IDS flexibly allow for complex, curvilinear and space-time-varying shapes of BSs. The proposed IDS presumes monitoring of the QE components of the normal stresses in BSs. The IDS is supposed to include an array of pressure-sensing resistors, also known as force-sensing resistors (FSRs), and communication hardware, as well as the parameter-identification software package (PISP), which provides the identification on the basis of the aforementioned PDE and the data measured by the FSRs. The IDS does not have hardware components located outside the outer surfaces of, or implanted in, BSs. The FSR array and communication hardware are reliable, and both cost- and energy-efficient. The present work extends methods of structural-health/operational-load monitoring (SH/OL-M) with measurements of the operational-load-caused stress in closed solid shells and, if the prospective PISP is used, endows the methods with identification of material parameters of the shells. The identification algorithms that can underlie the PISP are computationally efficient and suitable for implementation in the real-time mode. The identification model and algorithms can deal with not only

关键词： Non-Equilibrium Deformable Solid System Quasi-Equilibrium Mechanical Variable Average Normal Stress Pressure-Sensing Resistor Acoustics of Viscoelastic Solids Third-Order Partial Differential Equation Shell of a Blade of a Wind Turbine Atmospheric Ice Smart Deicing Structural-Health/Operational-Load Monitoring Identification of Material Parameters

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Applications of Dynamic-Equilibrium Continuous Markov Stochastic Processes to Elements of Survival Analysis

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Journal of Applied Mathematics and Physics 2019年第1期7卷 55-71页

作者： eugen mamontov Ziad Taib Early Clinical Biometrics Early Clinical DevelopmentIMED Biotech UnitAstraZenecaGothenburgSweden Versati AB AskimSweden

In this article, we summarize some results on invariant non-homogeneous and dynamic-equilibrium (DE) continuous Markov stochastic processes. Moreover, we discuss a few examples and consider a new application of DE processes to elements of survival analysis. These elements concern the stochastic quadratic-hazard-rate model, for which our work 1) generalizes the reading of its It? stochastic ordinary differential equation (ISODE) for the hazard-rate-driving independent (HRDI) variables, 2) specifies key properties of the hazard-rate function, and in particular, reveals that the baseline value of the HRDI variables is the expectation of the DE solution of the ISODE, 3) suggests practical settings for obtaining multi-dimensional probability densities necessary for consistent and systematic reconstruction of missing data by Gibbs sampling and 4) further develops the corresponding line of modeling. The resulting advantages are emphasized in connection with the framework of clinical trials of chronic obstructive pulmonary disease (COPD) where we propose the use of an endpoint reflecting the narrowing of airways. This endpoint is based on a fairly compact geometric model that quantifies the course of the obstruction, shows how it is associated with the hazard rate, and clarifies why it is life-threatening. The work also suggests a few directions for future research.

关键词： Non-Homogeneous Continuous Markov Stochastic Process Invariant Process Dynamic Equilibrium Diffusion Stochastic Process Ito Stochastic Ordinary Differential Equation Survival Analysis Hazard Rate Obstructive Lung Disease

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A Scalar Acoustic Equation for Gases, Liquids, and Solids, Including Viscoelastic Media

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Journal of Applied Mathematics and Physics 2014年第10期2卷 960-970页

作者： eugen mamontov Viktor Berbyuk Utilization Group Department of Research and Development Foundation Chalmers Industrial Technology Gothenburg Sweden Division of Dynamics Department of Applied Mechanics Chalmers University of Technology Gothenburg Sweden

The work deals with a mathematical model for real-time acoustic monitoring of material parameters of media in multi-state viscoelastic engineering systems continuously operating in irregular external environments (e.g., wind turbines in cold climate areas, aircrafts, etc.). This monitoring is a high-reliability time-critical task. The work consistently derives a scalar wave PDE of the Stokes type for the non-equilibrium part (NEP) of the average normal stress in a medium. The explicit expression for the NEP of the corresponding pressure and the solution-adequateness condition are also obtained. The derived Stokes-type wave equation includes the stress relaxation time and is applicable to gases, liquids, and solids.

关键词： Acoustic Monitoring Gas Liquid or Solid Acoustic Equation Visoelastic Media Stress Relaxation Time Average Normal Stress the Stokes-Type Wave Equation

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Propagation of Acoustic Waves Caused by the Accelerations of Vibrating Hand-Held Tools in Viscoelastic Soft Tissues of Human Hands and a Mechanobiological Picture for the Related Injuries

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Journal of Applied Mathematics and Physics 2017年第10期5卷 1997-2043页

作者： eugen mamontov Viktor Berbyuk Versati AB Askim Sweden Department of Mechanics and Maritime Sciences Chalmers University of Technology Gothenburg Sweden

As is well known, hand-arm vibration syndrome (HAVS), or vibration-induced white finger (VWF), which is a secondary form of Raynaud’s syndrome, is an industrial injury triggered by regular use of vibrating hand-held tools. According to the related biopsy tests, the main vibration-caused lesion is an increase in the thickness of the artery walls of the small arteries and arterioles resulted from enlarged vascular smooth muscle cells (VSMCs) in the wall layer known as tunica media. The present work develops a mechanobiological picture for the cell enlargement. The work deals with acoustic variables in solid materials, i.e., the non-equilibrium components of mechanical variables in the materials in the case where these components are weakly non-equilibrium. The work derives an explicit expression for the infinite-time cell-volume relative enlargement. This enlargement is directly affected by the acoustic pressure in the soft living tissue (SLT). In order to reduce the enlargement, one can reduce either the ratio of the acoustic pressure in the SLT to the cell bulk modulus or the relaxation time induced by the cell osmosis, or both the characteristics. Also, a mechanoprotective role of the above relaxation time in the cell-volume maintenance is noted. The above mechanobiological picture focuses attention on the pressure in an SLT and, thus, modeling of propagation of acoustic waves caused by the acceleration of a vibrating hand-held tool. The present work analyzes the propagation along the thickness of an infinite planar layer of an SLT. The work considers acoustic modeling. As a general viscoelastic acoustic model, the work suggests linear non-stationary partial integro-differential equation (PIDE) for the weakly non-equilibrium component of the average normal stress (ANS) or, briefly, the acoustic ANS. The PIDE is, in the exponential approximation for the normalized stress-relaxation function (NSRF) reduced to the third-order linear non-stationary partial differential

关键词： Mechanobiology Viscoelastic Soft Living Tissue Acoustic Wave Stress-Relaxation Time Third-Order Partial Differential Equation

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长寿命UHPFRC组合钢桥面板研究综述

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交通运输工程学报 2024年第1期24卷 68-84页

作者：段兰袁翊竑王春生 BRÜHWILER eugen 长安大学公路学院陕西西安710064 瑞士洛桑联邦理工学院结构维护与安全实验室沃州洛桑CH-1015

从三方面归纳与剖析了超高性能纤维增强水泥基(UHPFRC)复合材料组合钢桥面板的研究进展,包括强韧性组合层选材、界面传力机制与损伤累积机理、设计方法与工程应用;总结了纤维类型、纤维掺量对UHPFRC轴拉性能和抗弯性能的影响规律,确定... 详细信息

从三方面归纳与剖析了超高性能纤维增强水泥基(UHPFRC)复合材料组合钢桥面板的研究进展,包括强韧性组合层选材、界面传力机制与损伤累积机理、设计方法与工程应用;总结了纤维类型、纤维掺量对UHPFRC轴拉性能和抗弯性能的影响规律,确定了支撑组合钢桥面板结构分析的多种本构模型;对比分析了热连接、冷连接和混合连接组合界面设计方式的技术特点,归纳了胶粘界面、冷连接剪力键界面与混合连接界面的传力机理试验与理论研究成果;总结了基于冷连接设计理念的组合钢桥面板在合理构造、设计方法、规范规程与工程实践等方面的研究成果,并探讨了长寿命组合钢桥面板的创新与发展方向。研究结果表明:单一或混杂纤维的掺入综合提升了UHPFRC的应变强化能力、弯曲变形能力、抗断裂能力、裂缝宽度控制能力和抗疲劳性能,轴拉条件下UHPFRC三线型简化本构模型有力支撑了组合钢桥面板的设计计算,弹塑性损伤本构模型可描述不可逆疲劳损伤累积;验证了冷连接组合界面的增韧效果与可靠性,新型剪力键既可以提高组合效应,也能增韧UHPFRC层,混合连接界面具有降低界面局部应力集中、提高整体界面抗剪刚度、改善界面传力、提升施工效率等综合技术优势,内聚界面本构模型可实现冷连接界面损伤累积反演分析,界面损伤预测结果准确可靠;基于冷连接的UHPFRC组合钢桥面板可以有效提高钢桥面板的局部刚度,相关设计方法可支撑标准的编制与工程实践;应进一步提升UHPFRC的性价比和界面连接的高效性和可靠性,以支撑组合钢桥面板的长寿命、强韧性、轻量化、易维护、低能耗设计与建造。

关键词：桥梁工程长寿命 UHPFRC组合钢桥面板冷连接件组合界面设计准则免蒸养

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Reorganization of spinal neural circuitry and functional recovery after spinal cord injury

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Neural Regeneration Research 2015年第2期10卷 201-202页

作者： Raffaele Nardone eugen Trinka Department of Neurology Christian Doppler Klinik Paracelsus Medical University Spinal Cord Injury and Tissue Regeneration Center Paracelsus Medical University Department of Neurology Franz Tappeiner Hospital

The ability of the adult central nervous system to reorganize its circuits over time is the key to understand the functional improvement in subjects with spinal cord injury （SCI）. Adaptive changes within spared neuronal circuits may occur at cortical, brainstem, or spinal cord level, both above and below a spinal lesion （Bareyre et al., 2004）. At each level the reorganization is a very dynamic process, and its degree is highly variable, depending on several factors, including the age of the subject when SCI has occurred and the rehabilitative therapy. The use of electrophysiological techniques to assess these functional changes in neural networks is of great interest, because invasive methodologies as employed in preclinical models can obviously not be used in clinical studies.

关键词： SCI Reorganization of spinal neural circuitry and functional recovery after spinal cord injury TSR

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Detection of pathogenic bacteria by magneto-immunoassays:a review

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The Journal of Biomedical Research 2021年第4期35卷 277-283页

作者： eugen Gheorghiu International Centre of Biodynamics Bucharest 060101Romania.

Magnetic particle-based immunoassays are widely used in microbiology-related assays for both microbial capture,separation,analysis,and *** facilitating sample operation,the implementation of micro-to-nanometer scale magnetic beads as a solid support potentially shortens the incubation time(for magnetic immuno capture)from several hours to less than an *** technologies based on magnetic beads offer a rapid,effective and inexpensive way to separate and concentrate the target analytes prior to ***-immuno separation uses magnetic particles coated with specific antibodies to capture target microorganisms,bear the corresponding antigens,and subsequently separate them from the sample matrix in a magnetic *** method has been proven effective in separating various types of pathogenic bacteria from environmental water samples and in eliminating background *** particles are often used to capture target cells(pathogenic bacteria)from *** most commercially available assays,the actual identification and quantitation of the captured cells is then performed by classical microbiological *** review highlights the most sensitive analytic methods(i.e.,long-range surface plasmon resonance and electrochemical impedance spectroscopy)to detect magnetically tagged bacteria in conjunction with magnetic actuation.

关键词： magneto-immuno separation long-range surface plasmon resonance electrochemical impedance spectroscopy periodic magnetic actuation

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A review of the technologies for wave energy extraction

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Clean Energy 2018年第1期2卷 10-19页

作者： eugen Rusu Florin Onea Department of Mechanical Engineering “Dunarea de Jos”University of GalatiDomneasca Street47Galati 800008Romania

The main objective of this article is to provide a comprehensive picture of existing wave technologies being used for wave energy *** overview will explain their potential and also the challenges wave technologies *** article will also briefly discuss the benefits of combined offshore wind-wave projects,also known as *** factors and impacts on relevant existing wave technologies will be outlined,including capacity factor and capture *** the levelized cost of energy(LCOE)targets for the most promising technologies will be discussed.

关键词： wave power wave energy converters capacity factor capture width hybrid solutions

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Intestinal pseudo-obstruction:An uncommon condition with heterogeneous etiology and unpredictable outcome

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World Journal of Gastroenterology 2008年第6期14卷 954-959页

作者： eugen Florin Georgescu Ion Vasile Reanina Ionescu Filantropia University Hospital from Craiova Department of Internal Medicine 2 University of Medicine and Pharmacy of Craiova Romania Departmental Emergency University Hospital from Craiova Department of General Surgery 2 University of Medicine and Pharmacy of Craiova Romania

Intestinal pseudo-obstruction (IPO) either acute or chronic is a condition including features of intestinal ileus in absence of mechanical obstruction. Our paper presents such a rare case of idiopathic IPO in a 53-year-old male patient with recurrent episodes of pseudo-obstruction, which were successfully resolved by anticholinesterase agents, motilin agonists or colonic decompression. However, the patient finally underwent total colectomy. Huge colonic dilatation was identified intraoperatorily, while histology showed a neuropathic variant of chronic intestinal pseudo-obstruction. Etiologic mechanisms and current therapeutic methods are reviewed in this paper, which concludes that IPO is a condition in which conservative treatment usually fails. Total colectomy with ileoanal pouch may be the only solution in these situations.

关键词： Intestinal pseudo-obstruction Anticholinesterase agents Motilin receptor agonists Colonoscopic decompression Total colectomy with ileoanal pouch

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The Tibetan Local Self-defence Organizations in Amdo from 1900 to 1950

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中国藏学 1992年第S1期 315-321页

作者： eugen Wehrli

Introduction Several times explorers from western countries encounterd in Amdo well organised groups ofwarriors, and generally used the term "bandits" for them. The background of this explorers wascolonial, and for them it was out of question that such "primitive" nomads of farmers could ever or-ganize a regular army, which was in many aspects very similar to the ones in Europe at the

关键词：隆务寺部落马仲英阿坝白玉玉树

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