The European Physical Journal E最新文献

{"title":"Calorimetric, optical and dielectric measurements on two Schiff’s based liquid crystalline materials exhibiting multiple phase transitions","authors":"Prabir Sarkar,&nbsp;Barnali Barman,&nbsp;Parameswara Rao Alapati,&nbsp;Malay Kumar Das","doi":"10.1140/epje/s10189-024-00436-5","DOIUrl":"10.1140/epje/s10189-024-00436-5","url":null,"abstract":"<div><p>We report high-resolution calorimetric, optical and dielectric studies on two Schiff’s based liquid crystalline materials, 4O.5 and 5O.5, which exhibit multiple phase transitions. The study goes beyond the commonly studied isotropic-to-nematic (I–N) and nematic-to-smectic A (N–SmA) phase transitions and explores higher-order smectic phase transitions. The critical exponent, <i>α</i> values, for different phase transitions has been explored. For the I–N, N–SmA, SmA–SmC, SmC–SmF, SmF–CrG and SmB–CrG transitions, <i>α</i> values close to 0.5 and amplitude ratios <i>A</i>⁻/<i>A</i>⁺ ~ 1.6 and <i>D</i>⁻/<i>D</i>⁺ ~ 1 indicate a first-order nature. Notably, for the SmA–SmB transition, although <i>α</i> (≈ 0.64) is larger than the tricritical value of 0.5, <i>A</i>⁻/<i>A</i>⁺ ~ 1.2 and <i>D</i>⁻/<i>D</i>⁺ ~ 1, and the study reports an order parameter critical exponent (<i>β</i>) of 0.26 ± 0.002, which supports a tricritical nature for this transition. Importantly, the ratios of <i>A</i>⁻/<i>A</i>⁺ and <i>D</i>⁻/<i>D</i>⁺ are found to have similar values across all three-measurement methods, indicating consistency and agreement among these methods.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div><div><p>Optical textures of the SmF and CrG phases. Temperature dependence of birefringence for compounds 4O.5 and 5O.5</p></div></div></figure></div></div>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"47 6","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141441945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of the number of topological defects in active nematic fluids under applied shear flow","authors":"Zhenna Li,&nbsp;Hao Ye,&nbsp;Jianzhong Lin,&nbsp;Zhenyu Ouyang","doi":"10.1140/epje/s10189-024-00437-4","DOIUrl":"10.1140/epje/s10189-024-00437-4","url":null,"abstract":"<div><p>The number of topological defects in the shear flow of active nematic fluids is numerically investigated in this study. The evolution of the flow state of extensile active nematic fluids is explored by increasing the activity of active nematic fluids. Evidently, medium-activity active nematic fluids exhibit a highly ordered vortex lattice fluid state. However, high-activity active nematic fluids exhibit a meso-scale turbulent flow accompanied by topological defects. The number of topological defects (<i>N</i>_def) increases with increasing shear Reynolds number (<i>R</i>e_s). Fluid viscosity strongly influences <i>N</i>_def, while the influence of fluid density is relatively weak. <i>N</i>_def decreases with increasing activity length scale (<i>l</i>_<i>ζ</i>) value. A small <i>Re</i>_s value strongly influences <i>N</i>_def, whereas a large <i>l</i>_<i>ζ</i> value only weakly influences <i>N</i>_def. As the activity increases, <i>N</i>_def in contractile active nematic fluids becomes larger than that of extensile active nematic fluids.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div><div><p>Graphical abstract represents the flow state of meso-scale turbulent accompanied by topological defects. For the two dimensional case, two types of topological defects, namely comet-like + 1/2 and trefoil-like − 1/2 topological defects</p></div></div></figure></div></div>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"47 6","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141425944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structure-property modeling of physicochemical properties of fractal trigonal triphenylenoids by means of novel degree-based topological indices","authors":"K. Jyothish,&nbsp;Roy Santiago,&nbsp;S. Govardhan,&nbsp;Sakander Hayat","doi":"10.1140/epje/s10189-024-00438-3","DOIUrl":"10.1140/epje/s10189-024-00438-3","url":null,"abstract":"<p>Trigonal triphenylenoids (TTPs) are a fascinating class of organic molecules with unique structural and electronic properties. Their diverse applications, ranging from organic electronics to nonlinear optics, have spurred significant research interest in understanding their physicochemical behavior. Topological indices, mathematical descriptors derived from the molecular graph, offer valuable insights into the structural complexity and potential properties of TTPs. This work focuses on exploring the utility of degree-based topological indices in characterizing and predicting the properties of trigonal triphenylenoids. We systematically calculate various degree-based topological indices, for a diverse set of TTPs with varying substituents and topologies. The relationships between these indices and key physicochemical properties, such as HOMO-LUMO energy gap, thermodynamic stability, and reactivity are investigated using statistical and machine learning approaches. We identify significant correlations between specific degree-based indices and different properties, allowing for potential prediction of these properties based solely on the topological information.</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"47 6","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141417119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bifurcation analysis and control of improved traffic flow model considering the effect of strong winds","authors":"Wenhuan Ai,&nbsp;Zhengqing Lei,&nbsp;Danyang Li,&nbsp;Jingming Zeng,&nbsp;Dawei Liu","doi":"10.1140/epje/s10189-024-00433-8","DOIUrl":"10.1140/epje/s10189-024-00433-8","url":null,"abstract":"<div><p>In recent years, the problem of traffic congestion has become increasingly serious, and research on traffic system control has become a new hotspot. Studying the bifurcation characteristics of traffic flow systems and designing control schemes for unstable support points can alleviate traffic congestion from a new perspective. This article improves the full speed differential model considering strong wind models from the perspective of bifurcation control to adjust traffic flow. This article theoretically proves the existence conditions of Hopf bifurcation and saddle node bifurcation in the model and finds the stability mutation point of the transportation system stability. A nonlinear system feedback controller was designed for unstable bifurcation points using Chebyshev polynomial approximation and random feedback control methods. Without changing the system equilibrium point, the advance, delay, and elimination of Hopf bifurcation were achieved, and the abrupt behavior of the transportation system was controlled, thereby alleviating traffic congestion. This article explains the changes in the stability of complex transportation systems from the perspective of bifurcation analysis, which can better capture the characteristics of traffic flow. By adjusting the control parameters in the feedback controller, the influence of boundary conditions on the stability of the transportation system is fully described, and the influence of unstable focal points and saddle points on the system is suppressed, thereby slowing down the traffic flow. In addition, unstable bifurcation points can be eliminated, and the Hopf bifurcation can be controlled to advance, delay, and disappear, thereby achieving control over the stable behavior of the transportation system. This helps alleviate traffic congestion and also helps describe actual traffic phenomena.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div><div><p>Schematic diagram of the force situation of vehicles under wind force</p></div></div></figure></div></div>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"47 6","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141330082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phase separation, edge currents, and Hall effect for active matter with Magnus dynamics","authors":"B. Adorjáni,&nbsp;A. Libál,&nbsp;C. Reichhardt,&nbsp;C. J. O. Reichhardt","doi":"10.1140/epje/s10189-024-00431-w","DOIUrl":"10.1140/epje/s10189-024-00431-w","url":null,"abstract":"<p>We examine run-and-tumble disks in two-dimensional systems where the particles also have a Magnus component to their dynamics. For increased activity, we find that the system forms a motility-induced phase-separated (MIPS) state with chiral edge flow around the clusters, where the direction of the current is correlated with the sign of the Magnus term. The stability of the MIPS state is non-monotonic as a function of increasing Magnus term amplitude, with the MIPS region first extending down to lower activities followed by a break up of MIPS at large Magnus amplitudes into a gel-like state. We examine the dynamics in the presence of quenched disorder and a uniform drive and find that the bulk flow exhibits a drive-dependent Hall angle. This is a result of the side jump effect produced by scattering from the pinning sites and is similar to the behavior found for skyrmions in chiral magnets with quenched disorder.</p><p>Active Magnus particles without pinning or drift force in the presence of gradually increasing Magnus terms showing <b>a</b> a rotating cluster mode, <b>b</b> a rotating cluster with clear shear banding at its edge, <b>c</b> a sheared band spanning the system, and <b>d</b> a disordered state where neither clusters nor shear bands can form. The colors indicate the net displacement of the particles, while the arrows show the rotation or shear directions</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"47 6","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141282662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the fluid drag reduction in scallop surface","authors":"Botong Li,&nbsp;Zitian Zhao,&nbsp;Linyu Meng,&nbsp;Liangliang Zhu","doi":"10.1140/epje/s10189-024-00434-7","DOIUrl":"10.1140/epje/s10189-024-00434-7","url":null,"abstract":"<div><p>In the field of biomimetics, the tiny riblet structures inspired by shark skin have been extensively studied for their drag reduction properties in turbulent flows. Here, we show that the ridged surface texture of another swimming creature in the ocean, i.e., the scallops, also has some friction drag reduction effect. In this study, we investigated the potential drag reduction effects of scallop shell textures using computational fluid dynamics simulations. Specifically, we constructed a conceptual model featuring an undulating surface pattern on a conical shell geometry that mimics scallop. Simulations modeled turbulent fluid flows over the model inserted at different orientations relative to the flow direction. The results demonstrate appreciable friction drag reduction generated by the ribbed hierarchical structures encasing the scallop, while partial pressure drag reduction exhibits dependence on alignment of scallop to the predominant flow direction. Theoretical mechanisms based on classic drag reduction theory in turbulence was established to explain the drag reduction phenomena. Given the analogous working environments of scallops and seafaring vessels, these findings may shed light on the biomimetic design of surface textures to enhance maritime engineering applications. Besides, this work elucidates an additional evolutionary example of fluid drag reduction, expanding the biological repertoire of swimming species.</p><h3>Graphical abstract</h3><p>Lines used for shear stress data extraction of the shell model and the normalized wall shear of these lines on both models.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"47 6","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141199221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrating machine learning with (alpha )-SAS for enhanced structural analysis in small-angle scattering: applications in biological and artificial macromolecular complexes","authors":"Eugen Mircea Anitas","doi":"10.1140/epje/s10189-024-00435-6","DOIUrl":"10.1140/epje/s10189-024-00435-6","url":null,"abstract":"<p>Small-Angle Scattering (SAS), encompassing both X-ray (SAXS) and Neutron (SANS) techniques, is a crucial tool for structural analysis at the nanoscale, particularly in the realm of biological macromolecules. This paper explores the intricacies of SAS, emphasizing its application in studying complex biological systems and the challenges associated with sample preparation and data analysis. We highlight the use of neutron-scattering properties of hydrogen isotopes and isotopic labeling in SANS for probing structures within multi-subunit complexes, employing techniques like contrast variation (CV) for detailed structural analysis. However, traditional SAS analysis methods, such as Guinier and Kratky plots, are limited by their partial use of available data and inability to operate without substantial <i>a priori</i> knowledge of the sample’s chemical composition. To overcome these limitations, we introduce a novel approach integrating <span>(alpha )</span>-SAS, a computational method for simulating SANS with CV, with machine learning (ML). This approach enables the accurate prediction of scattering contrast in multicomponent macromolecular complexes, reducing the need for extensive sample preparation and computational resources. <span>(alpha )</span>-SAS, utilizing Monte Carlo methods, generates comprehensive datasets from which structural invariants can be extracted, enhancing our understanding of the macromolecular form factor in dilute systems. The paper demonstrates the effectiveness of this integrated approach through its application to two case studies: Janus particles, an artificial structure with a known SAS intensity and contrast, and a biological system involving RNA polymerase II in complex with Rtt103. These examples illustrate the method’s capability to provide detailed structural insights, showcasing its potential as a powerful tool for advanced SAS analysis in structural biology.</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"47 6","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141236262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A microfluidic platform for the synthesis of polymer and polymer-protein-based protocells","authors":"Jessica Ann O’Callaghan,&nbsp;Neha P. Kamat,&nbsp;Kevin B. Vargo,&nbsp;Rajarshi Chattaraj,&nbsp;Daeyeon Lee,&nbsp;Daniel A. Hammer","doi":"10.1140/epje/s10189-024-00428-5","DOIUrl":"10.1140/epje/s10189-024-00428-5","url":null,"abstract":"<p>In this study, we demonstrate the fabrication of polymersomes, protein-blended polymersomes, and polymeric microcapsules using droplet microfluidics. Polymersomes with uniform, single bilayers and controlled diameters are assembled from water-in-oil-in-water double-emulsion droplets. This technique relies on adjusting the interfacial energies of the droplet to completely separate the polymer-stabilized inner core from the oil shell. Protein-blended polymersomes are prepared by dissolving protein in the inner and outer phases of polymer-stabilized droplets. Cell-sized polymeric microcapsules are assembled by size reduction in the inner core through osmosis followed by evaporation of the middle phase. All methods are developed and validated using the same glass-capillary microfluidic apparatus. This integrative approach not only demonstrates the versatility of our setup, but also holds significant promise for standardizing and customizing the production of polymer-based artificial cells.</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"47 6","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11147907/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141199220","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of local incompressibility on the rheology of composite biopolymer networks","authors":"Anupama Gannavarapu,&nbsp;Sadjad Arzash,&nbsp;Iain Muntz,&nbsp;Jordan L. Shivers,&nbsp;Anna-Maria Klianeva,&nbsp;Gijsje H. Koenderink,&nbsp;Fred C. MacKintosh","doi":"10.1140/epje/s10189-024-00422-x","DOIUrl":"10.1140/epje/s10189-024-00422-x","url":null,"abstract":"<p>Fibrous networks such as collagen are common in biological systems. Recent theoretical and experimental efforts have shed light on the mechanics of single component networks. Most real biopolymer networks, however, are composites made of elements with different rigidity. For instance, the extracellular matrix in mammalian tissues consists of stiff collagen fibers in a background matrix of flexible polymers such as hyaluronic acid (HA). The interplay between different biopolymer components in such composite networks remains unclear. In this work, we use 2D coarse-grained models to study the nonlinear strain-stiffening behavior of composites. We introduce a local volume constraint to model the incompressibility of HA. We also perform rheology experiments on composites of collagen with HA. Theoretically and experimentally, we demonstrate that the linear shear modulus of composite networks can be increased by approximately an order of magnitude above the corresponding moduli of the pure components. Our model shows that this synergistic effect can be understood in terms of the local incompressibility of HA, which acts to suppress density fluctuations of the collagen matrix with which it is entangled.</p><p>A snapshot of a composite network on a triangular lattice. Collagen fibers (black) interact with a hyaluronic acid matrix, represented by both dashed lines and gray hexagons that resist volume change. </p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"47 5","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141157349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Texture identification in liquid crystal-protein droplets using evaporative drying, generalized additive modeling, and K-means Clustering","authors":"Anusuya Pal,&nbsp;Amalesh Gope","doi":"10.1140/epje/s10189-024-00429-4","DOIUrl":"10.1140/epje/s10189-024-00429-4","url":null,"abstract":"<p>Sessile drying droplets manifest distinct morphological patterns, encompassing diverse systems, viz., DNA, proteins, blood, and protein-liquid crystal (LC) complexes. This study employs an integrated methodology that combines drying droplet, image texture analysis (features from First Order Statistics, Gray Level Co-occurrence Matrix, Gray Level Run Length Matrix, Gray Level Size Zone Matrix, and Gray Level Dependence Matrix), and statistical data analysis (Generalized Additive Modeling and K-means clustering). It provides a comprehensive qualitative and quantitative exploration by examining LC-protein droplets at varying initial phosphate buffered concentrations (0x, 0.25x, 0.5x, 0.75x, and 1x) during the drying process under optical microscopy with crossed polarizing configuration. Notably, it unveils distinct LC-protein textures across three drying stages: initial, middle, and final. The Generalized Additive Modeling (GAM) reveals that all the features significantly contribute to differentiating LC-protein droplets. Integrating the K-means clustering method with GAM analysis elucidates how textures evolve through the three drying stages compared to the entire drying process. Notably, the final drying stage stands out with well-defined, non-overlapping clusters, supporting the visual observations of unique LC textures. Furthermore, this paper contributes valuable insights, showcasing the efficacy of drying droplets as a rapid and straightforward tool for characterizing and classifying dynamic LC textures.</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"47 5","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11126455/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141086434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}