检索结果-内蒙古大学图书馆

viscoelasticity of PPA/SBS/SBR Composite Modified Asphalt and Asphalt Mixtures Under Pressure Aging Conditions

POLYMERS 2025年第5期17卷 698页

作者： Yu, Zongjie Ling, Xinpeng Fan, Ze Zhou, Yueming Ma, Zhu Changsha Univ Sci & Technol Coll Transportat Engn Changsha 410114 Peoples R China Xinjiang Inst Transportat Sci Co Ltd Urumqi 830000 Peoples R China Key Lab Highway Engn Technol & Transportat Ind Ari Urumqi 830000 Peoples R China Xinjiang Highway & Bridge Testing & Inspect Ctr Co Urumqi 830000 Peoples R China

The viscoelastic behavior of asphalt mixtures is a crucial consideration in the analysis of pavement mechanical responses and structural design. This study aims to elucidate the molecular structure and component evolution trends of polyphosphoric acid (PPA)/styrene butadiene styrene block copolymer (SBS)/styrene butadiene rubber copolymer (SBR) composite modified asphalt (CMA) under rolling thin film oven test (RTFOT) and pressure aging (PAV) conditions, as well as to analyze the viscoelastic evolution of CMA mixtures. First, accelerated aging was conducted in the laboratory through RTFOT, along with PAV tests for 20 h and 40 h. Next, the microscopic characteristics of the binder at different aging stages were explored using Fourier-transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC) tests. Additionally, fundamental rheological properties and temperature sweep tests were performed to reveal the viscoelastic evolution characteristics of CMA. Ultimately, the viscoelastic properties of CMA mixtures under dynamic loading at different aging stages were clarified. The results indicate that the incorporation of SBS and SBR increased the levels of carbonyl and sulfoxide factors while decreasing the level of long-chain factors, which slowed down the rate of change of large molecule content and reduced the rate of change of LMS by more than 6%, with the rate of change of overall molecular weight distribution narrowing to below 50%. The simultaneous incorporation of SBS and SBR into CMA mixtures enhanced the dynamic modulus in the 25 Hz and -10 degrees C range by 24.3% (AC-13), 15.4% (AC-16), and reduced the phi by 55.8% (AC-13), 40% (AC-16). This research provides a reference for the application of CMA mixtures in the repair of pavement pothole damage.

关键词： road engineering PPA/SBS/SBR composite modified asphalt mixture FTIR GPC viscoelasticity dynamic modulus

来源：评论

学校读者我要写书评

暂无评论

viscoelasticity-contrast driven electrohydrodynamic behaviour of a droplet-suspended-in-a-confined-liquid configuration

引用

JOURNAL OF NON-NEWTONIAN FLUID MECHANICS 2025年 338卷

作者： Gupta, Pulak Dhar, Purbarun Samanta, Devranjan Indian Inst Technol Ropar Dept Mech Engn Ropar 140001 Punjab India Indian Inst Technol Kharagpur Dept Mech Engn Hydrodynam & Thermal Multiphys Lab HTML Kharagpur 721302 West Bengal India

We present an approximate analytical model (without compromise on the physics) of the electrohydrodynamics (EHD) of a confined leaky dielectric, non-Newtonian viscoelastic droplet suspended in a surrounding medium of similar characteristics. The analysis considers the Stokes flow regime through a small deformation formulation. The viscoelastic behaviour is realized by coupling the Cauchy momentum equation with the upper convected Maxwell (UCM) model. Since the study is limited to low electric field intensities, the governing Weissenberg number (Wi) <= 1. We consider various combinations of the droplet and the surrounding, viz. NN-N, N-NN, and NN-NN cases. A thorough comparison with the N-N case is conducted. Here, 'N' represents Newtonian and 'NN' represents non-Newtonian. The solution put forward is validated with experimental observations in literature and works successfully in the regime of low electric field strength. We show that, for an unconfined domain, the deformation is maximum for the N-N case and least for the N-NN case, thus establishing the role of viscoelasticity-contrast. For the confined domain, we have also observed shape reversal in N-NN and NN- NN cases at higher confinement (alpha) and lower electro-rheological parameter (delta). For NN-N, the deformation is greater compared to the N-N case beyond a critical alpha. We also report the streamline patterns within the droplet and in the surrounding medium for various cases and for different confinement. The findings reveal shape reversal phenomena in confined viscoelastic cases, and provide insights into the EHD with fluidic confinement, offering potential avenues for the design and functionality of microfluidic devices.

关键词： Droplets Electrohydrodynamics Rheology viscoelasticity Wiessenberg number Confinement

来源：评论

学校读者我要写书评

暂无评论

viscoelasticity, logarithmic stresses, and tensorial transport equations

引用

MATHEMATICAL METHODS IN THE APPLIED SCIENCES 2025年第3期48卷 2934-2953页

作者： Ciampa, Gennaro Giusteri, Giulio G. Soggiu, Alessio G. Univ Aquila DISIM Dipartimento Ingn & Sci Informaz & Matemat Milan Italy Univ Padua Dipartimento Matemat Tullio Levi Civita Via Trieste 63 I-35131 Padua Italy

We introduce models for viscoelastic materials, both solids and fluids, based on logarithmic stresses to capture the elastic contribution to the material response. The matrix logarithm allows to link the measures of strain, that naturally belong to a multiplicative group of linear transformations, to stresses, that are additive elements of a linear space of tensors. As regards the viscous stresses, we simply assume a Newtonian constitutive law, but the presence of elasticity and plastic relaxation makes the materials non-Newtonian. Our aim is to discuss the existence of weak solutions for the corresponding systems of partial differential equations in the nonlinear large-deformation regime. The main difficulties arise in the analysis of the transport equations necessary to describe the evolution of tensorial measures of strain. For the solid model, we only need to consider the equation for the left Cauchy-Green tensor, while for the fluid model, we add an evolution equation for the elastically-relaxed strain. Due to the tensorial nature of the fields, available techniques cannot be applied to the analysis of such transport equations. To cope with this, we introduce the notion of charted weak solution, based on non-standard a priori estimates, that lead to a global-in-time existence of solutions for the viscoelastic models in the natural functional setting associated with the energy inequality.

关键词： logarithmic strain tensorial transport equation viscoelasticity weak solution

来源：评论

学校读者我要写书评

暂无评论

Interpenetrating Polymer Network Hydrogels with Tunable viscoelasticity and Proteolytic Cleavability to Direct Stem Cells In Vitro

引用

ADVANCED HEALTHCARE MATERIALS 2025年第9期14卷 e2402656页

作者： Seth, Prannoy Friedrichs, Jens Limasale, Yanuar Dwi Putra Fertala, Nicole Freudenberg, Uwe Zhang, Yixin Lampel, Ayala Werner, Carsten Leibniz Inst Polymer Res Dresden Max Bergmann Ctr Biomat Dresden D-01069 Dresden Germany Tech Univ Dresden Cluster Excellence Phys Life D-01307 Dresden Germany Tech Univ Dresden B CUBE Ctr Mol Bioengn D-01307 Dresden Germany Tel Aviv Univ George S Wise Fac Life Sci Ctr Nanosci Shmunis Sch Biomed & Canc Res IL-69978 Tel Aviv Israel Tel Aviv Univ Nanotechnol Sagol Ctr Regenerat Biotechnol IL-69978 Tel Aviv Israel Tel Aviv Univ Ctr Phys & Chem Living Syst IL-69978 Tel Aviv Israel Tech Univ Dresden Ctr Regenerat Therapies Dresden & Cluster Excellen D-01062 Dresden Germany

The dynamic nature of cellular microenvironments, regulated by the viscoelasticity and enzymatic cleavage of the extracellular matrix, remains challenging to emulate in engineered synthetic biomaterials. To address this, a novel platform of cell-instructive hydrogels is introduced, composed of two concurrently forming interpenetrating polymer networks (IPNs). These IPNs consist of the same basic building blocks - four-armed poly(ethylene glycol) and the sulfated glycosaminoglycan (sGAG) heparin - are cross-linked through either chemical or physical interactions, allowing for precise and selective tuning of the hydrogel's stiffness, viscoelasticity, and proteolytic cleavability. The studies of the individual and combined effects of these parameters on stem cell behavior revealed that human mesenchymal stem cells exhibited increased spreading and Yes-associated protein transcriptional activity in more viscoelastic and cleavable sGAG-IPN hydrogels. Furthermore, human induced pluripotent stem cell (iPSC) cysts displayed enhanced lumen formation, growth, and pluripotency maintenance when cultured in sGAG-IPN hydrogels with higher viscoelasticity. Inhibition studies emphasized the pivotal roles of actin dynamics and matrix metalloproteinase activity in iPSC cyst morphology, which varied with the viscoelastic properties of the hydrogels. Thus, the introduced sGAG-IPN hydrogel platform offers a powerful methodology for exogenous stem cell fate control.

关键词： dynamic matrix restructuring interpenetrating sGAG hydrogels proteolytic cleavability stem cell morphogenesis viscoelasticity

来源：评论

学校读者我要写书评

暂无评论

A novel mechanistic model for predicting shrinkage kinetics in plant-based foods by integrating solid matrix mobility and viscoelasticity

引用

JOURNAL OF FOOD ENGINEERING 2025年 387卷

作者： Tuly, Sumaiya Sadika Joardder, Mohammad U. H. Welsh, Zachary G. Karim, Azharul Queensland Univ Technol Fac Engn Mech Med & Proc Engn Brisbane Qld Australia Rajshahi Univ Engn & Technol Dept Mech Engn Rajshahi 6204 Bangladesh

Deformation during drying is a major physical change influencing drying kinetics and final product quality. Therefore, accurate prediction of shrinkage kinetics is essential for determining the optimal drying conditions for these foods. Shrinkage kinetics is greatly influenced by their structural mobility (rubbery-glassy transition) and viscoelastic properties. The current deformation models lack a comprehensive integration of structural mobility and viscoelasticity concepts, resulting in limitation in attaining insights on physiochemical state variations and viscoelastic stresses developed during drying. In order to overcome this limitation, this study proposes a novel mechanistic shrinkage model that combines solid matrix mobility-based shrinkage velocity and viscoelasticity consideration, incorporating variable mechanical properties to simulate deformation arising from moisture loss and pressure gradient respectively. Comparison between predicted drying kinetics and shrinkage evolution with experimental observation yielded close agreement, achieving low mean absolute error values. As the drying process progressed, a distinct anisotropic shrinkage pattern emerged, which is attributed to varied structural mobility based on temperature and moisture distribution across the food sample. Notably, shrinkage driven by moisture loss significantly outweighed that induced by pressure, exerting a predominant influence on overall volume change. Furthermore, the model demonstrated heightened sensitivity to water transport parameters compared to mechanical factors, which indicates the significance of moisture dynamics in shaping the drying process. Combined consideration of physiochemical changes and viscoelastic concept in the developed deformation model extends new possibility towards optimizing the drying process as well as quality aspect evaluation.

关键词： Anisotropic shrinkage Mechanistic approach Structural mobility viscoelasticity Physical quality

来源：评论

学校读者我要写书评

暂无评论

Effect of Compressive Strain Rates on viscoelasticity and Water Content in Intact Porcine Stomach Wall Tissues

引用

JOURNAL OF BIOMECHANICAL ENGINEERING-TRANSACTIONS OF THE ASME 2025年第2期147卷 021002页

作者： Udayamohan, Vijay Shashank Byju, Achu Geetha Harris, Jason L. Haridas, Balakrishna Texas A&M Univ Dept Mech Engn 9201 Warm Springs Cir Plano TX 75024 USA Texas A&M Univ Dept Biomed Engn 101 Bizzell St3120 TAMU College Stn TX 77843 USA Ethicon Endosurg 4545 Creek Rd Cincinnati OH 45242 USA Texas A&M Univ Dept Biomed 101 Bizzell St3120 TAMU College Stn TX 77843 USA Texas A&M Univ Dept Mech Engn 101 Bizzell St3120 TAMU College Stn TX 77843 USA

Laparoscopic staplers are used extensively to seal and transect tissue. These devices compress tissue between the stapler jaws to achieve a desired compressed tissue thickness in preparation for stapling. The extent and rate of compression are dependent on surgeon technique, tissue characteristics, and stapler type, all of which can impact stapling outcomes such as bleeding, staple line leaks, and tissue healing. Historically, surgeons have relied on their experience, training, and tactile feedback from the device to optimize stapling. In recent years, the transition to electromechanical and robotic staplers has greatly impacted the tactile feedback available to the surgeon. This raises new questions about the optimal rates of tissue compression and the resultant tissue forces. This study quantifies the transmural biomechanics of the porcine stomach wall. Multirate indentation tests were used to observe the effects of indentation rate on the viscoelastic behavior of the stomach tissue during indentation, stress relaxation, and unconstrained recovery. Results show that the stomach wall demonstrates higher stress relaxation (88% versus 80%) and greater strain recovery (52% versus 47%) when indented at high rates (37.5%/s) versus slow rates (7.5%/s). Additionally, water content analysis was used to study fluid flow away from indented regions. Unindented regions were found to have greater water content compared to indented regions (78% compared to 75%). This data generated in this study may be used to enable the development of constitutive models of stomach tissue, which in turn may inform the control algorithms that drive compressive surgical devices.

关键词： Testing viscoelasticity Surgery Stress Compression Relaxation (Physics) Biological tissues Water

来源：评论

学校读者我要写书评

暂无评论

Stress relaxation and viscous energy in nonlinear viscoelasticity: A rational extended thermodynamics framework

引用

JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS 2025年 196卷

作者： Amabili, Marco Arima, Takashi Ruggeri, Tommaso Westlake Univ Sch Engn Hangzhou Zhejiang Provin Peoples R China Natl Inst Technol Tomakomai Coll Dept Engn Innovat Tomakomai 0591275 Japan Univ Bologna Dept Math Via Saragozza 8 I-40123 Bologna Italy Acad Nazl Lincei Rome Italy

We investigate uniaxial stress relaxation under constant strain using a recent hyperbolic model of nonlinear viscoelasticity based on the principles of Rational Extended Thermodynamics, as proposed in Ruggeri (2024). We determine the viscous dissipated energy such that the stress decays over time as a combination of exponential functions (Prony Series) with different relaxation times. We show that the obtained viscous energy satisfies all the requirements of the model such that the original system is symmetric hyperbolic and in particular satisfy the dissipation principle. According to the model, which requires that the viscous energy depends solely on the viscous stress, we are able to determine the analytical form of the coefficients in terms of the initial step deformation. This approach allows us to predict the decay of the viscous stress for any deformation jump, relying only on the fitting coefficients obtained from an experiment. This fully nonlinear viscoelastic model can be applied in conjunction with any hyperelastic law for the quasi-static stress component. We successfully applied our results to reproduce experimental data from uniaxial relaxation tests of a woven Dacron fabric currently used in aortic grafts.

关键词： Stress relaxation viscoelasticity Nonlinear viscoelasticity Rational extended thermodynamics Nonlinear elasticity

来源：评论

学校读者我要写书评

暂无评论

Effect of moisture migration on texture and viscoelasticity of Chinese yam during multi-phase microwave drying (MMD) - focusing on the evaporation-dehydration stage

引用

FOOD CHEMISTRY-X 2025年 26卷 102314页

作者： Yang, Mengmeng Chen, Xinyi Wang, Lijuan Ren, Xing Liu, Wenchao Li, Linlin Ren, Guangyue Law, Chung Lim Cao, Weiwei Zhang, Min Chen, Junliang Lu, Donghe Duan, Xu Henan Univ Sci & Technol Coll Food & Bioengn Luoyang 471000 Peoples R China Ningxia Med Univ Coll Basic Med Sci Yinchuan 750004 Peoples R China Henan Prov Engn Res Ctr Agr Prod Proc Equipment Luoyang 471000 Peoples R China Henan Prov Engn Technol Res Ctr Agr Prod Drying Eq Luoyang 471000 Peoples R China Univ Nottingham Dept Chem & Environm Engn Malaysia Campus Semenyih 43500 Selangor Malaysia Fujian Acad Agr Sci Inst Food Sci & Technol Fuzhou 350003 Peoples R China

This study aimed to assess the correlation between moisture migration and texture, as well as viscoelasticity of Chinese yam during the evaporation stage of multiphase microwave drying (MMD). A comparison of different drying strategies (Scheme I, Scheme II, and Scheme III) revealed that the water molecule mobility decreased as drying proceeded. In samples with higher water content at the transition point, the rapid migration of water during evaporation stage could result in a more pronounced collapse of the cellular and pore structure, leading to a denser product with increased hardness. Additionally, changes in the samples' textural and viscoelastic properties were significantly correlated with the moisture states. As water mobility decreased, the movement of molecular chains was restricted, leading to increased rigidity in the sample. These findings can provide theoretical guidance for the process optimization of MMD to meet consumers' demand for high-quality dried products.

关键词： Multiphase microwave drying Moisture migration Texture viscoelasticity Mechanism

来源：评论

学校读者我要写书评

暂无评论

Influence of refreshment varying flour and water on sourdough viscoelasticity and textural properties of bread

引用

CEREAL CHEMISTRY 2025年第1期102卷 144-156页

作者： Espinoza-Acosta, Jose L. Navarro-Euan, Melina J. Buitimea-Cantua, Nydia E. Chan-Higuera, Jesus E. Bernal-Mercado, Ariadna T. Dorame-Miranda, Ramon F. Gerardo-Rodriguez, Jesus E. Univ Estatal Sonora UES Navojoa Sonora Mexico Univ Sonora Dept Invest & Posgrad Alimentos Hermosillo 83000 Sonora Mexico

Background and ObjectiveSourdough involves spontaneous fermentation by wild yeast and lactic acid bacteria. This study investigates the effects of varying water and flour proportions on sourdough and formulated dough viscoelasticity and bread textural properties after a 7-day refreshment period. Daily, 20% or 30% water and 30% or 40% flour were added using refined or 20% fiber-enriched flour. The pH and titratable acidity of the sourdough were measured, while dynamic frequency sweep tests were conducted to assess the viscoelastic properties of both sourdough and formulated dough. Additionally, the textural parameters of bread were *** pH of the sourdough was lower when refined flour was used, but total titratable acidity analyses indicated higher acidity with 20% fiber-enriched flour, demonstrating greater efficacy in this study. In the sourdough, G '' exceeded G ', indicating a more pronounced viscous behavior. Conversely, in the formulated dough, G ' was higher, suggesting greater elasticity. The treatment involving 20% water and 40% refined flour resulted in higher G ' and G '' values in both the sourdough and formulated dough. Meanwhile, the combination of 20% water and 30% refined flour produced bread with the highest specific volume and springiness, along with the lowest firmness, chewiness, and *** best bread was achieved with 20% water and 30% refined flour for *** and NoveltyThis study provides insights for optimizing sourdough formulations, benefiting artisanal and industrial bread-making.

关键词： bread texture sourdough refreshment viscoelasticity water and flour proportions

来源：评论

学校读者我要写书评

暂无评论

Towards linking histological changes to liver viscoelasticity: a hybrid analytical-computational micromechanics approach

引用

PHYSICS IN MEDICINE AND BIOLOGY 2025年第4期70卷 045005-045005页

作者： Shah, Haritya Guddati, Murthy N. North Carolina State Univ Raleigh NC 27695 USA

Motivated by elastography that utilizes tissue mechanical properties as biomarkers for liver disease, with the eventual objective of quantitatively linking histopathology and bulk mechanical properties, we develop a micromechanical modeling approach to capture the effects of fat and collagen deposition in the liver. Specifically, we utilize computational homogenization to convert the microstructural changes in hepatic lobule to the effective viscoelastic modulus of the liver tissue, i.e. predict the bulk material properties by analyzing the deformation of repeating unit cell. The lipid and collagen deposition is simulated with the help of ad hoc algorithms informed by histological observations. Collagen deposition is directly included in the computational model, while composite material theory is used to convert fat content to the microscopic mechanical properties, which in turn is included in the computational model. The results illustrate the model's ability to capture the effect of both fat and collagen deposition on the viscoelastic moduli and represents a step towards linking histopathological changes in the liver to its bulk mechanical properties, which can eventually provide insights for accurate diagnosis with elastography.

关键词： viscoelasticity homogenization steatosis micromechanics elastography

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：