The conformational possibilities of the rubiscolin-6 molecule (Tyr1-Pro2-Leu3-Asp4-Leu5-Phe6-NH2) were investigated using theoretical conformational analysis. The potential function of the system was chosen as the sum of non-bonded, electrostatic, and torsional interactions, as well as hydrogen bond energy. Low-energy conformations of the rubiscolin-6 molecule were found, with values of dihedral angles for the main and side chains of the amino acid residues involved in the molecule’s structure, and the energy of intra- and inter-residue interactions was assessed. It was shown that the spatial structure of the rubiscolin-6 molecule consists of conformations of eight shapes of the peptide backbone. The results obtained may be used to investigate the structural and structure-function organization of the rubiscolin-6 molecule.
It has been observed that there is a significant correlation between bioactivity and the mathematical descriptors of a molecule. Topological indices (TI) serve as vital predictive instruments for pharmaceutical compounds because they reveal structural patterns of organotin (IV) carboxylates and other bioactive substances. Consequently, TIs find extensive therapeutic applications in studying antiproliferative effects, fungicide resistance, antibiotic resistance, anti-inflammatory activity, antiparasitic activity and enzyme inhibition. Analysis of degree-based TIs provides essential insights into optimal treatment approaches, as well as toxicity and side effects related to organotin (IV) carboxylate drugs. This predictive capability facilitates the design of safer, more efficient medications. The discovery of new substances has benefited from TIs through the identification of critical structural-property relationships during drug synthesis. The current study employs graph-based topological indices and a regression model to evaluate how these descriptors determine the physicochemical, as well as biological features of novel pharmaceutical compounds. These findings establish an investigation into new therapeutic agents by assessing their multi-functional biological potential.
The dielectric relaxation behaviour of sodium silicate (Na 2 SiO[Formula: see text] was examined using complex impedance spectroscopy (CIS) over a broad frequency range (100–5[Formula: see text]MHz) and at varying temperatures (50–450 ∘ C). The orthorhombic crystal phase was synthesized through sintering. CIS analysis indicated high complex impedance in the low-frequency range, signifying significant dispersion linked to the ion or cation relaxation mechanisms within the crystal lattice. A decrease in energy loss ([Formula: see text] with increasing frequency was observed at all temperatures, aligning with typical behaviour for sodium silicate. The relaxation times were calculated using dielectric functions [Formula: see text] and [Formula: see text]. The temperature-dependent relaxation plot followed Arrheniu’s law, where the slope corresponds to the activation energy. This analysis provides insights into the frequency-dependent dielectric properties and the relaxation processes in sodium silicate, highlighting the influence of temperature on ionic movement within the crystal structure.
The purpose of this paper is to discuss the usage of topological indices and Entropy for Quantitative structure–property relationship (QSPR) to anticipate the physical and biological aspects of innovative drugs used in the treatment of anticancer disease. By using topological indices that represent the structural features of the molecular graphs, a series of incorporation entropic indices can be developed for the quantitative characterisation of molecular complexity and variation. Degree-based topological indices and Entropy were generated using edge partitioning to assess the drugs such as Dacomitinib, Afatinib, Neratinib, Nazartinib, Avitinib and Osimertinib by using python algorithm. Then, using linear and Logarithmic regression, a QSPR model is developed to predict characteristics such as Polarisability, Molar Refractivity, Surface Tension, Molar Volume, Complexity and Molecular Weight. Therefore, by applying these models, the study will extend the capabilities of QSPR analysis and provide a solid ground for assessing the eligibility of the potential drug candidates. The findings show that topological indices and Entropy have the potential to be used as a tool for drugs discovery and design in the field of anticancer disease treatment.
Mathematical chemistry is concerned with the use of mathematics to solve problems in chemistry. In chemistry, the molecules are frequently shown as graphs with vertices denoting atoms and edges denoting bonds, respectively. Atom valences and bond multiplicities are represented by vertex degrees and edge multiplicities, respectively. The vertices in a graph are said to be close by if an edge connects them. Alkanes are a class of compounds whose physical characteristics are modeled using the chemical graph theory. The melting and boiling points of the molecules are modeled using topological indices based on the graphical structure of the alkanes. A mesh network is a local area network in which the infrastructure nodes (i.e., bridges, switches, and other infrastructure devices) connect directly, dynamically, and non-hierarchically to as many other nodes as possible and cooperate with one another to efficiently route data. In this paper, the distinct degrees of triangular mesh network, enhanced mesh network, rhenium trioxide lattice network, and star of silicate network are listed with the edge partitions technique. We determined the first (second) Zagreb indices, the modified second Zagreb index, the symmetric division index, the harmonic index, and the inverse sum index. In Sec. 2 , we characterized the detailed proofs of these indices for each triangular network. Based on our obtained results, we give a graphical representation and comparison between certain topological indices. These computed indices are highly accurate in the study of QSPRs and QSARs because they have the best correlation with the acentric factor and entropy.
Background: The materials used in prosthetic components for lower limb amputees, which frequently could not support the essential dynamics for movement at slower rates, previously restricted their mobility. However, novel elements have enabled ausability while aiding individuals in overcoming physical limitations. Object: This study investigated the mechanical, thermal, and morphological properties of prosthetic feet. Method: Employing a modular system technique, six polypropylene laminates reinforced with fibers (Kevlar, N-glass, Carbon, Perlon, and glass fibers) were created. These laminates were then put through tensile, compressive, impact, DSC, surface roughness, and SEM tests. The rule of mixtures was used to obtain density and volume fraction. Results: Hybrid Perlon, carbon, and Kevlar fibers demonstrated the highest tensile, compressive strength, fracture toughness, impact performance, and surface roughness. According to DSC data, mixing different synthetic fibers had an impact on the crystallization temperatures, and the glass transition temperature rose as the number of layers increased. When compared to other hybrid materials, the Kevlar/carbon hybrid composite exhibited fewer flaws on its fractured surface, as indicated by SEM scans. Conclusions: These results demonstrate the intriguing possibilities of orthopedic feet as well as the encouraging developments in biomedical engineering.
The cold target recoil ion momentum spectroscopy (COLTRIMS) imaging technique was used to study the kinetic energy release (KER) from the fragmentation of [Formula: see text] molecular ions produced in transfer ionisation (TI) collisions of 0.4[Formula: see text]MeV He[Formula: see text] ions with nitrogen molecules. The measurements involved the determination of the impact positions of the fragments on the recoil detector and the time-coincidence between the fragment ions resulting from the dissociation and scattered projectiles. The momentum vectors of the fragments were determined from the position and time information, and the kinetic energy release distributions were obtained from the momentum distributions of the fragments.
This study presents a molecular dynamics investigation of the mechanical behaviour and dislocation evolution in FCC metal nanopillars (Al, Au, Cu, Ni) and their composites reinforced with (8,0) zigzag carbon nanotubes (CNTs). Uniaxial tensile and compressive loading simulations were conducted across a wide temperature range to evaluate the impact of CNT reinforcement on elastic and plastic response. The results show that CNT inclusion significantly enhances Young’s modulus and ultimate tensile strength, particularly at lower temperatures. Dislocation analysis using the Dislocation Extraction Algorithm (DXA) reveals substantial modifications in the nucleation, propagation and interaction of dislocations in the presence of CNTs. In CNT-reinforced systems, dislocation activity is suppressed or delayed, and complex dislocation networks form near the CNT interface. These findings offer valuable insights into nanoscale reinforcement mechanisms and support the design of high-performance, thermally stable metal–CNT nanocomposites.
The two-center overlap integrals in the molecular coordinate system over Slater-type orbitals are expressed in terms of newly defined functions, which are evaluated recursively and are closely related to the well-known incomplete gamma functions. Using the well-known rotational properties of spherical harmonics, the rotation matrices, also referred to as rotation coefficients, were calculated. Rotation matrices were expressed in terms of Gaunt coefficients and complex spherical harmonics. They were computed in two different ways: in the first approach, the Gaunt coefficients and normalized complex spherical harmonics were directly evaluated using binomial coefficients, while in the second, both quantities were obtained recursively. The numerical stability of our computational results was analyzed. In the calculation of overlap integrals and rotation matrices, both methods were compared in terms of accuracy and computation time (CPU) for low and very high quantum numbers.
This paper reports the use of molecular dynamics simulations to obtain structural information on sodium borophosphate glasses containing niobium. The results were compared with high-energy X-ray diffraction, neutron diffraction, Raman and IR spectroscopy, X-ray absorption measurements and NMR data to investigate the effects of niobium incorporation on the structure and properties of these glasses. The simulation results show good agreement with the experimental data. As expected, both boron (B) and phosphorus (P) act as tetrahedral network formers. The number of Nb-Nb linkages increases with increasing niobium content, initially leading to corner-sharing and then forming interconnected NbO6 units. At low niobium content, Nb adopts an off-center position within the octahedral site, and the distortion of the NbO6 units increases as niobium content rises. Additionally, as the niobium concentration increases, more phosphorus atoms form bonds with other network formers.
This paper investigates plane wave propagation in orthotropic micropolar media using nonlocal strain gradient theory. We derive the characteristic equation for surface wave existence, which reduces to classical gradient strain, nonlocal, and classical elasticity theories as special cases. Dispersion equation for the propagation of Rayleigh-type waves at the free surface has been derived. Moreover, it is found that the dimensionless wave velocities demonstrate either stiffness-softening or stiffness-hardening behavior, depending on the relative values of the nonlocal parameter and material length scale.
This study investigates the effects of copper–graphene interfaces and grain boundaries on phonon-thermal conductivity in copper–graphene composites. The investigation was carried out using atomistic modelling through molecular dynamics (MD) simulations. Graphene’s exceptional thermal conductivity makes it a promising candidate for enhancing heat transfer in electronic devices. However, when integrated into copper matrices, the presence of defects like high-angle grain boundaries and interfacial regions can significantly alter heat dissipation. The results show that introducing a graphene layer into the copper matrix reduces the composite’s thermal conductivity by 40%, from [Formula: see text] [Formula: see text]W/m*K to [Formula: see text] [Formula: see text]W/m*K. The introduction of high-angle grain boundaries in copper further decreases the thermal conductivity to [Formula: see text] [Formula: see text]W/m*K as far as grain boundaries in the copper matrix lead to significant phonon scattering. Moreover, the presence of defects in both graphene and copper reduces thermal conductivity to [Formula: see text] [Formula: see text]W/m*K. The combined effect of copper–graphene interfaces and grain boundaries in both materials leads to the most substantial reduction in thermal conductivity, reaching [Formula: see text] [Formula: see text]W/m*K. These findings demonstrate the critical role of interface and grain boundary defects in modulating the thermal performance of copper–graphene composites and provide insights for optimising the thermal design of advanced materials for thermal management applications.
Journal of Micromechanics and Molecular PhysicsAccepted Papers No AccessMolecular Dynamics Simulation of Tensile Deformation Mechanisms in Nanocrystalline TWIP SteelRanran Zhang, Brahmanandam Javvaji, Haifei Zhan, Min Xia, Manchao He, Xiaolong Fu, and Xiaoying ZhuangRanran Zhang, Brahmanandam Javvaji Search for more papers by this author , Haifei Zhan Search for more papers by this author , Min Xia Search for more papers by this author , Manchao He Search for more papers by this author , Xiaolong Fu Search for more papers by this author , and Xiaoying Zhuanghttps://orcid.org/0000-0001-6562-2618 Search for more papers by this author https://doi.org/10.1142/S2424913025500018Cited by:0 (Source: Crossref) Next AboutFiguresReferencesRelatedDetailsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsRecommend to Library ShareShare onFacebookTwitterLinked InRedditEmail Cite Recommend We recommendLANGEVIN MOLECULAR DYNAMICS DERIVED FROM EHRENFEST DYNAMICSANDERS SZEPESSY, Mathematical Models and Methods in Applied Sciences, 2012Acupuncture for Pain Management: Molecular Mechanisms of ActionTeng Chen, The American Journal of Chinese Medicine, 2020Unveiling Pyrolysis Mechanisms of Waste Printed Circuit Boards Through Multiphysics SimulationQiwei Xiong, Journal of Circuits, Systems and Computers, 2024A MOLECULAR DYNAMICS STUDY OF NANOWIRE RESONATOR BIO-OBJECT DETECTIONROSA FALLAHPOUR, Journal of Mechanics in Medicine and Biology, 2021NUMERICAL SIMULATION OF HEMODYNAMICS IN PORTAL VEIN WITH THROMBOSIS BY COMPUTATIONAL FLUID DYNAMICSXINKAI WANG, Journal of Mechanics in Medicine and Biology, 2014Molecular Dynamics Simulation of MNT Xuesong Han, Bentham Science BooksMolecular Dynamics Simulation of Nanoflow Inside Non-Smooth Pipe Wenfei Zhang, Micro and Nanosystems, 2011Molecular Docking, Molecular Dynamics Simulation, and Analysis of EGFR-derived Peptides against the EGF Samaneh Ghasemali, Letters in Drug Design & Discovery, 2023Synthesis, anti-acetylcholinesterase evaluation, molecular docking and molecular dynamics simulation of novel Psoralen derivatives Aso Hameed Hasan, Current Organic Synthesis, 2023Design and screening of KLHL22 inhibitors by homology modeling, molecular docking, and molecular dynamics simulation. Chenglong Gao, Letters in Drug Design & Discovery, 2022Powered by Privacy policyGoogle Analytics settings FiguresReferencesRelatedDetailsNone Recommended Accepted Papers Metrics Downloaded 0 times History Received 24 October 2024 Accepted 5 January 2025 PDF download
Quantum and molecular mechanics based electronic energy studies of weak H-bonded ammonium dimer show distinctive feature in energy profile when computed by different QM methods contrast to MM methods. MM based MMFF and SYBYL methods show smoothly varying dihedral energy profile for torsion angle variation around weak N1-H5 held by H-bond strength of around 13 KJ/mol. All the QM based methods HF, B3LYP and MP2 show noisy and unstable torsion dependent electronic energy profile for H-bonded ammonium dimer. Exploring energy surface beyond bond length shows singularities and discontinuities. QM-based computation of dipole moment shows several discreet values with jumps and discontinuities with torsion angle variation for ammonium dimer. Also repeated computations and reverse torsion energy profile show persistent singularity feature observed in all standard QM techniques. KEY WORDS: ammonium dimer, H-bond, quantum signature, anisotropic energy singularities
In the framework of teleparallel tachyonic model, we explore the stability of the generalized thermodynamical law and equilibrium case at Hubble horizon together with Bekenstein entropy at present as well as past epoch for flat Friedmann–Lemaître–Robertson–Walker metric. For this purpose, we take three distinct models of Hubble parameter in terms of redshift. Also, we choose power-law correction terms and specific coupling of scalar field and take observational values from [Formula: see text] dataset and compare results of all different models.
Through the reconstructed kernel particle method (RKPM), the dynamic buckling characteristics of submarine pressure hull under hydrostatic pressure and impact load is investigated in this study. First, a large deformation buckling calculation model for stiffened shell structures was established using RKPM and elastic–plastic constitutive models. To study the influence of load asymmetry on the buckling strength of the structure and provide fundamental technical support for submarine structural design, the dynamic buckling phenomenon of the structure was studied under three conditions: hydrostatic pressure acting alone, hydrostatic pressure and impact load acting simultaneously, and hydrostatic pressure and uniformly distributed impact load acting simultaneously. The starting time of buckling was used as the criterion for determining the critical load of dynamic buckling. The results indicate that under the combined action of static and dynamic loads, asymmetric dynamic loads can seriously affect the buckling strength of the structure.
The conformational possibilities of the ovalulin (Tyr1-Pro2-Leu3-Asp4-Leu5-Phe6-OH) molecule were studied by theoretical conformational analysis. The potential function of the system is chosen as the sum of non-valence, electrostatic, and torsion interactions and the energy of hydrogen bonds. The low-energy conformations of the ovalulin molecule, the dihedral angles of the main and side chains of the amino acid residues that make up the molecule were found, and the energy of intra- and inter-residual interactions was estimated. It has been shown that the spatial structure of the ovalulin molecule is represented by conformations of eight shapes of the peptide skeleton. The results obtained can be used to elucidate the structural and structural-functional organization of the ovalulin molecule.
ZnO nanoparticle/poly(3-hexylthiophene) conducting polymer hybrid nanocomposite photoanode has been grown on FTO-coated glass substrates. ZnO nanoparticles (ZnO NPs) were synthesised using sol–gel methods. Structural and optical properties of ZnO NPs studied using AFM, TEM and UV–Vis spectroscopy. The size of the ZnO nanoparticles varies from 10[Formula: see text]nm to 45[Formula: see text]nm. The photoelectrochemical properties of the P3HT film, ZnO nanoparticles and ZnO/P3HT nanocomposite photoanodes have been studied under dark and illumination of white light. The ZnO/P3HT hybrid photoanode shows photosensing properties with a high on-off ratio (∼90) at 0[Formula: see text]V. Open circuit photovoltage (OCPV) response and OCPV delay of ZnO/P3HT nanocomposite has been studied. The stability of ZnO nanoparticle-poly(3-hexylthiophene) nanocomposite as a photoanode has been investigated using 1[Formula: see text]Hz chopped light pulse.
This study explores the utilization of topological graph invariants, or molecular descriptors, to mathematically model chemical compounds. These descriptors are vital in quantifying the physio-chemical characteristics of a compound, and are commonly represented as shapes such as polygons, bushes, and grapes. Specifically, this research focuses on computing selected fifth multiplicative first and second Zagreb indices, third and fourth multiplicative general fifth multiplicative Zagreb indices, and other degree-based topological indices for the benzene ring graph ([Formula: see text] and the simple bounded dual of benzene ring graph ([Formula: see text]. The findings of this study are then compared to demonstrate the impact of these molecular descriptors.
Mathematical Chemistry is concerned with the use of mathematics to solve problems in Chemistry. In Chemistry, the molecules are frequently shown as graphs with vertices denoting atoms and edges denoting bonds, respectively. Atom valences and bond multiplicities are represented by vertex degrees and edge multiplicities, respectively. The vertices in a graph are said to be close by if an edge connects them. Alkanes are a class of compounds whose physical characteristics are modelled using the chemical graph theory. The melting and boiling points of the molecules are modelled using topological indices based on the graphical structure of the alkanes. A mesh network is a local area network, in which the infrastructure nodes (i.e., bridges, switches and other infrastructure devices) connect directly, dynamically and non-hierarchically to as many other nodes as possible and cooperate with one another to efficiently route data. In this paper, the distinct degrees of triangular mesh network, enhanced mesh network, rhenium tri-oxide lattice network and star of silicate network are list with edge partitions technique. We determine the first and second Zagreb index, the modified second Zagreb index, the symmetric division index, the harmonic index and the inverse sum index. We characterise detailed proofs of these indices for each triangular network. Furthermore, their graphical representation and comparison between the certain topological indices is presented in Sec. 6. These indices are highly accurate in the study of QSPRs and QSARs because they have strong correlation with the acentric factor and entropy.
