Article
Chemistry, Physical
Kunyun He, Ye Zhou, Hadi Ramezani-Dakhel, Juan J. de Pablo, Alberto Fernandez-Nieves, Teresa Lopez-Leon
Summary: In this study, we investigate the possibility of inducing valence transitions by transforming a nematic shell into a nematic droplet. We observe two different scenarios, where the inner droplet either shrinks and disappears, inducing a defect reorganization, or is expelled from the shell, abruptly changing the system's geometry. Numerical simulations and modeling are used to understand the origin and mechanism of these behaviors.
Article
Multidisciplinary Sciences
Luka Mesarec, Wojciech Gozdz, Veronika Kralj-Iglic, Samo Kralj, Ales Iglic
Summary: The impact of the intrinsic curvature of in-plane orientationally ordered curved flexible nematic molecules attached to closed 3D flexible shells was studied numerically. A Helfrich-Landau-de Gennes-type mesoscopic approach was adopted where the flexible shell's curvature field and in-plane nematic field are coupled and concomitantly determined in the process of free energy minimisation. We demonstrate that this coupling has the potential to generate a rich diversity of qualitatively new shapes of closed 3D nematic shells and the corresponding specific in-plane orientational ordering textures, which strongly depend on the shell's volume-to-surface area ratio, so far not predicted in mesoscopic-type numerical studies of 3D shapes of closed flexible nematic shells.
SCIENTIFIC REPORTS
(2023)
Article
Physics, Fluids & Plasmas
Seyed Reza Seyednejad, Mohammad Reza Mozaffari
Summary: Symmetric nematic liquid crystal shells exhibit stable configurations energetically, while in thick shells, the director field shows bipolar and hexadecapolar configurations between boundaries, and in thin shells, boojums transform into two stable disclination curves.
Article
Chemistry, Physical
Mujan N. Seif, Matthew J. Beck
Summary: The utilization of DFT and DFPT calculations in computing free energies and constructing particle configuration maps reveals the critical role of Ba in controlling the shape and surface chemistry of W particles in application-relevant conditions. These system-specific findings demonstrate the broad power of DFT+DFPT computed particle configuration maps in revealing connections between particle behavior and properties as a function of experimentally-relevant conditions.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Physical
Gaetano Napoli, Oleksandr Pylypovskyi, Denis D. Sheka, Luigi Vergori
Summary: In this study, a parallel is drawn between ferromagnetic materials and nematic liquid crystals confined on curved surfaces within the framework of continuum theory. It is shown that the combination of extrinsic curvature of the shell and the out-of-plane component of the director field leads to chirality effects. Furthermore, the different nature of the order parameter results in different textures on surfaces with the same topology.
Article
Multidisciplinary Sciences
Priyanka Kumari, Bijaya Basnet, Hao Wang, Oleg D. Lavrentovich
Summary: Solid ferroelectrics have aligned polarization along crystallographic axes, with different polarization domains separated by flat domain walls. In a ferroelectric nematic liquid crystal without crystallographic axes or facets, domain walls shape as conic sections to bisect the angle between neighboring polarization fields and avoid electric charges. The intrinsic properties of conic sections play a central role in liquid ferroelectrics.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Physical
C. B. de Araujo, E. J. L. de Oliveira, M. L. Lyra, L. Mirantsev, I. N. de Oliveira
Summary: This study investigates the behavior of dumbbell-shaped nematic liquid crystal shells under an external electric field through molecular dynamics simulations. The results show that the number and location of topological defects are strongly influenced by the external field, and the equilibrium configuration of orientational ordering depends on the field direction. Additionally, the effects of varying the shell's Gaussian curvature on the liquid crystal shells are analyzed.
Article
Chemistry, Physical
D. J. G. Pearce
Summary: This study investigates the curved nematic textures on the surface of a cylinder and finds that the phase of the topological defects is coupled to the orientation of the cylinder, depending on the relative energetic cost associated with splay, bend and twist distortions. The study also reveals a bistability in the phase of the defects when twist deformations dominate.
Article
Chemistry, Physical
Azat O. Tipeev, Jose P. Rino, Edgar D. Zanotto
Summary: The surface free energy of solids, gamma, was successfully obtained for the first time from molecular dynamics simulations using a crystal cleavage method, avoiding surface premelting. The temperature dependence of gamma was explored in a Lennard-Jones system, showing good agreement with indirect values.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Nicholas A. Szaro, Mubarak Bello, Charles H. Fricke, Olajide H. Bamidele, Andreas Heyden
Summary: This study compares the accuracy of DFT and RPA methods for the ethane dehydrogenation reaction on Pt(111), finding that PBE and RPBE without dispersion correction can closely model the energy calculated by RPA. However, RPA fails to accurately describe the gas phase energy as unsaturation and chain-length increase in hydrocarbons. RPBE has the best accuracy-to-cost ratio, suggesting that RPA may not be superior to RPBE or BEEF-vdW.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Engineering, Civil
H. Bagheri, Y. Kiani, M. R. Eslami
Summary: In this study, the natural frequencies of a conical-spherical functionally graded material (FGM) shell were investigated using the first order shear deformation theory and Donnel type of kinematic assumptions. The system of equations was discretized using the semi-analytical generalized differential quadrature (GDQ) method, and an eigenvalue problem was established to examine the vibration frequencies.
THIN-WALLED STRUCTURES
(2021)
Article
Engineering, Civil
H. Bagheri, Y. Kiani, M. R. Eslami
Summary: This study investigates natural frequencies of a conical-spherical functionally graded material (FGM) shell using advanced theories and methods. Through numerical simulations and parametric studies, conclusions regarding the efficiency and validity of the system's performance are drawn.
THIN-WALLED STRUCTURES
(2021)
Article
Engineering, Civil
H. Bagheri, Y. Kiani, M. R. Eslami
Summary: This study investigates the natural frequencies of conical-spherical functionally graded material (FGM) shells, showing the effectiveness of the method in dealing with the vibration problems of FGM shell materials.
THIN-WALLED STRUCTURES
(2021)
Article
Materials Science, Multidisciplinary
Yanli Lin, Linghui He, Renhuai Liu
Summary: The study suggests that for glassy nematic shallow spherical shells with hemeotropic director alignment, snap-through can be induced by incident light with moderate irradiation intensity, potentially inspiring new designs for contactless and ultra-fast actuation devices with high-rate output of mechanical work.
ACTA MECHANICA SOLIDA SINICA
(2022)
Article
Chemistry, Physical
Luka Mesarec, Ales Iglic, Samo Kralj
Summary: In this study, we numerically investigate the ordering profiles and topological defect configurations in thin nematic liquid crystalline shells controlled by local distortion of the liquid crystalline order. It is found that the geometry of the shell and the spatial variation of the local Gaussian curvature strongly influence the manipulations.
EUROPEAN PHYSICAL JOURNAL E
(2022)
Article
Acoustics
Riccardo De Pascalis, Gaetano Napoli, Giuseppe Saccomandi
Article
Mathematics, Applied
Gaetano Napoli, Riccardo De Pascalis
ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND PHYSIK
(2019)
Article
Materials Science, Multidisciplinary
Gaetano Napoli, Alain Goriely
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2020)
Correction
Mechanics
Gaetano Napoli, Stefano Turzi
Article
Multidisciplinary Sciences
D. De Tommasi, G. Devillanova, F. Maddalena, G. Napoli, G. Puglisi
Summary: This study investigates instability effects due to geometric constraints in nonlinear elasticity by analyzing equilibrium configurations of an elastic ring constrained inside a rigid circle. Different possible shapes are determined, with single-blister solutions having the lowest energy. The model's effectiveness is tested through a simple experiment involving a thin polymer strip in a rigid cylinder.
PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2021)
Article
Optics
Giuseppe Bevilacqua, Valerio Biancalana, Yordanka Dancheva, Alessandro Fregosi, Gaetano Napoli, Antonio Vigilante
Summary: A newly introduced tuning-dressed scheme allows the Bell and Bloom magnetometer to detect small variations in radio-frequency magnetic fields, serving as an alternative to RF atomic magnetometers.
Article
Multidisciplinary Sciences
M. Curatolo, G. Napoli, P. Nardinocchi, S. Turzi
Summary: The study describes and investigates an active elastic instability occurring in a swollen spherical closed shell during a dehydration process. Numerical experiments based on a stress-diffusion model and a semi-analytical model are established to understand the phenomenon. The semi-analytic model matches the outcomes of the numerical experiments and discusses the ranges of validity of the approximated analytical model.
PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2021)
Article
Physics, Multidisciplinary
Samuele De Bartolo, Stefano Rizzello, Ennio Ferrari, Ferdinando Frega, Gaetano Napoli, Raffaele Vitolo, Michele Scaraggi, Carmine Fallico, Gerardo Severino
Summary: The research suggests that braided channels in rivers exhibit multicursal behavior during flood events, with scale measurements still not well understood due to the lack of a general procedure. By using a stochastic approach based on Taylor's law and exponential dispersion distributions, the scaling behavior of hydraulically active channels can be analyzed effectively.
EUROPEAN PHYSICAL JOURNAL PLUS
(2022)
Article
Mechanics
Salvatore Di Stefano, Giuseppe Florio, Gaetano Napoli, Nicola M. Pugno, Giuseppe Puglisi
Summary: In this study, we investigate the behavior of the interactions between focal adhesions and the extra-cellular matrix in a mechanical setting. We propose a three-layers mechanical system and use an analytical approach to describe the transition from elastic regime to decohesion. We find that the relative stiffness of the layers plays a critical role in the decohesion behavior, and the proposed model effectively predicts the mechanical behavior of decohesion phenomena in biological systems.
INTERNATIONAL JOURNAL OF NON-LINEAR MECHANICS
(2022)
Article
Physics, Multidisciplinary
M. Curatolo, F. Lisi, G. Napoli, P. Nardinocchi
Summary: A cylindrical hydrogel tube undergoes hydration and dehydration processes when submerged in water and exposed to air, respectively. The dehydration process leads to circumferential buckling due to the depression in the tube cavity. A continuous model combining nonlinear elasticity with Flory-Rehner theory is used to study this buckling phenomenon and determine the threshold value for buckling. The results obtained from the model are consistent with finite element simulations.
EUROPEAN PHYSICAL JOURNAL PLUS
(2023)
Article
Chemistry, Physical
Arsenio Cutolo, Massimiliano Fraldi, Gaetano Napoli, Giuseppe Puglisi
Summary: We investigate the equilibrium configurations of an elastic fiber growing in a confined, flexible ring. This system is widely applicable to biological, medical, and engineering problems. Using a simplified geometry where the initial container is a circular ring of radius R, we study the quasi-static growth by solving equilibrium equations as the fiber length l increases from l = 2R. By considering the fiber and ring as inextensible and unshearable, we find that the fiber buckles beyond a critical length that depends on the relative bending stiffness. Additionally, as the fiber continues to grow, it folds and distorts the ring, breaking the mirror symmetry at l > 2 pi R. We determine that the equilibrium shapes depend on two dimensionless parameters: the length ratio mu = l/R and the bending stiffnesses ratio kappa. These findings are corroborated by finite element simulations. Experimental validation shows excellent quantitative agreement with the observed buckling and folding regimes at varying geometrical parameters.
Article
Engineering, Multidisciplinary
G. Napoli, G. Puglisi
Summary: This study investigates the delamination phenomenon of glued slender devices and provides practical solutions. It further explores the relationship between formulation and conditions.
APPLICATIONS IN ENGINEERING SCIENCE
(2022)
Article
Chemistry, Physical
Gaetano Napoli, Oleksandr Pylypovskyi, Denis D. Sheka, Luigi Vergori
Summary: In this study, a parallel is drawn between ferromagnetic materials and nematic liquid crystals confined on curved surfaces within the framework of continuum theory. It is shown that the combination of extrinsic curvature of the shell and the out-of-plane component of the director field leads to chirality effects. Furthermore, the different nature of the order parameter results in different textures on surfaces with the same topology.
Article
Physics, Fluids & Plasmas
Gaetano Napoli, Luigi Vergori
Summary: The study investigates the temperature-induced isotropic-nematic phase transition on a spherical shell under the assumption of degenerate tangential anchoring within the framework of Landau-de Gennes theory. It finds the exact critical threshold value for the temperature and determines the nematic textures at the transition through weakly nonlinear analysis. The stability analysis shows that only the tetrahedral configuration is stable at the isotropic-nematic transition.
Article
Physics, Fluids & Plasmas
Gaetano Napoli, Stefano Turzi
