An efficient computational procedure to obtain a more stable glass structure

2019 ◽  
Vol 151 (22) ◽  
pp. 224502 ◽  
Author(s):  
Shingo Urata
Keyword(s):  
Glass Structure ◽  
Computational Procedure ◽  
Stable Glass

Properties of Silica Glass Doped with Titanium Oxide

2008 ◽  
Vol 39-40 ◽  
pp. 153-158 ◽  
Author(s):  
V. Pukh ◽  
L. Baikova ◽  
M. Kireenko ◽  
L. Tikhonova
Keyword(s):  
Titanium Oxide ◽  
Silica Glass ◽  
Glass Fibers ◽  
Glass Structure ◽  
Anomalous Behavior ◽  
Metallic Alloys ◽  
Low Thermal Expansion ◽  
Stable Glass ◽  
Intrinsic Strength ◽  
Polymorphous Transformations

The features of anomalous behavior of silica glass doped with titanium oxide are discussed. The low thermal expansion of silica glass is considered on the base of the idea about polymorphous transformations in meta-stable glass structures. The analogy of these transformations to structural transitions of martensite type in metallic alloys is assumed. The effect of TiO2-doping on the structure and the intrinsic strength of silica glass fibers is studied. The structural (intrinsic) strength has been found to decrease by about 15% compared to that of non-doped silica glass. This decrease of strength is assumed to be accounted for the incorporation of a part of titanium ions into glass structure with six-fold coordination resulting in weakening the connectivity of a glass anionic network.

A New Computational Procedure for Heat Transfer and Pressure Drop During Refrigerant Condensation Inside Enhanced Tubes

1999 ◽  
Vol 6 (6) ◽  
pp. 441-456 ◽  
Author(s):  
Luca Doretti ◽  
Luisa Rossetto ◽  
Giovanni A. Longo ◽  
Alberto Cavallini ◽  
Davide Del Col
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Computational Procedure ◽  
Enhanced Tubes

A New Computational Procedure to Predict Transient Hydroplaning Performance of a Tire

2001 ◽  
Vol 29 (1) ◽  
pp. 2-22 ◽  
Author(s):  
T. Okano ◽  
M. Koishi
Keyword(s):  
Complex Geometry ◽  
Fluid Flows ◽  
Computational Procedure ◽  
Vehicle Body ◽  
Fluid Viscosity ◽  
Safe Driving ◽  
Transient Phenomena ◽  
Vehicle Velocity ◽  
Fixed Reference ◽  
Volume Method

Abstract “Hydroplaning characteristics” is one of the key functions for safe driving on wet roads. Since hydroplaning depends on vehicle velocity as well as the tire construction and tread pattern, a predictive simulation tool, which reflects all these effects, is required for effective and precise tire development. A numerical analysis procedure predicting the onset of hydroplaning of a tire, including the effect of vehicle velocity, is proposed in this paper. A commercial explicit-type FEM (finite element method)/FVM (finite volume method) package is used to solve the coupled problems of tire deformation and flow of the surrounding fluid. Tire deformations and fluid flows are solved, using FEM and FVM, respectively. To simulate transient phenomena effectively, vehicle-body-fixed reference-frame is used in the analysis. The proposed analysis can accommodate 1) complex geometry of the tread pattern and 2) rotational effect of tires, which are both important functions of hydroplaning simulation, and also 3) velocity dependency. In the present study, water is assumed to be compressible and also a laminar flow, indeed the fluid viscosity, is not included. To verify the effectiveness of the method, predicted hydroplaning velocities for four different simplified tread patterns are compared with experimental results measured at the proving ground. It is concluded that the proposed numerical method is effective for hydroplaning simulation. Numerical examples are also presented in which the present simulation methods are applied to newly developed prototype tires.

Spatial temperature distribution in CW CO2 laser photosensitized reactions

1984 ◽  
Vol 49 (6) ◽  
pp. 1354-1359 ◽  
Author(s):  
Pavel Kubát ◽  
Josef Pola
Keyword(s):  
Temperature Distribution ◽  
Chemical Reactions ◽  
Co2 Laser ◽  
Computational Procedure ◽  
Heat Convection ◽  
Inert Gas ◽  
Spatial Temperature Distribution ◽  
Cw Co2 Laser ◽  
Spatial Temperature

The temperature distribution in gaseous SF6 and SF6-inert gas samples under irradiation with cw CO2 laser measured by a thermocouple technique is confronted with the results of a computational procedure neglecting heat convection. The results are helpful in understanding the effect of the inert gas on the distribution of temperature and the size of the reacting hot volume in the cw laser-photosensitized chemical reactions.

Dependence between calculated flexibility of lamellas of layered materials and their ability to undergo intercalation reactions

1991 ◽  
Vol 56 (12) ◽  
pp. 2859-2868 ◽  
Author(s):  
Jiří Votinský ◽  
Ludvík Beneš
Keyword(s):  
Computational Procedure ◽  
Layered Materials ◽  
Space Group

A computational procedure has been suggested enabling estimates of the flexibility of individual layered materials from their crystallographical structure. The data about flexibility of layers have been obtained by calculation for compounds of the type Q2Y3 (Q = SbIII, BiIII; Y = Se-II, Te-II; space group of symmetry R3m), MPS3 (M = MnII, FeII, CoII, NiII, CdII,C2/m), TX2 (T = NbIV, TaIV, MoV; X = S-II, Se-II; P63/mmc), FeOCl (Pmnm), Zr(HPO4)2 (P21/n) and ROPO4 (R = VV, NbV, Mo; P4/n). The flexibility of the layers of these compounds increases in the order: Q2Y3 << MPS3 < TX2 < FeOCl = Zr(HPO4)2 < ROPO4. The same trend is observed for the ability of these compounds to form intercalates. In most of the structures given a distinct anisotropy of flexibility has been found by the calculation.

scholarly journals A computational framework to establish data-driven constitutive models for time- or path-dependent heterogeneous solids

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Weijian Ge ◽  
Vito L. Tagarielli
Keyword(s):  
Constitutive Models ◽  
Computational Procedure ◽  
Data Driven ◽  
Dissipated Energy ◽  
Computational Framework ◽  
Heterogeneous Solids ◽  
Non Linear ◽  
Recorded Data ◽  
Path Dependent ◽  
Computational Homogenisation

AbstractWe propose and implement a computational procedure to establish data-driven surrogate constitutive models for heterogeneous materials. We study the multiaxial response of non-linear n-phase composites via Finite Element (FE) simulations and computational homogenisation. Pseudo-random, multiaxial, non-proportional histories of macroscopic strain are imposed on volume elements of n-phase composites, subject to periodic boundary conditions, and the corresponding histories of macroscopic stresses and plastically dissipated energy are recorded. The recorded data is used to train surrogate, phenomenological constitutive models based on neural networks (NNs), and the accuracy of these models is assessed and discussed. We analyse heterogeneous composites with hyperelastic, viscoelastic or elastic–plastic local constitutive descriptions. In each of these three cases, we propose and assess optimal choices of inputs and outputs for the surrogate models and strategies for their training. We find that the proposed computational procedure can capture accurately and effectively the response of non-linear n-phase composites subject to arbitrary mechanical loading.

scholarly journals DC and AC Conductivity, Biosolubility and Thermal Properties of Mg-Doped Na2O–CaO–P2O5 Glasses

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2626
Author(s):  
Natalia Anna Wójcik ◽  
Sharafat Ali ◽  
Jakub Lech Karczewski ◽  
Bo Jonson ◽  
Michał Bartmański ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Saline Solution ◽  
Glass Structure ◽  
Glass Network ◽  
Bioactive Glasses ◽  
Dc And Ac Conductivity ◽  
Impedance Spectroscopy Technique ◽  
Mg Content ◽  
Phosphate Buffered Saline ◽  
Mg Doped

Bioactive glasses have recently been extensively used to replace, regenerate, and repair hard tissues in the human body because of their ability to bond with living tissue. In this work, the effects of replacing Na2O with MgO on the electrical, biosolubility, and thermal properties of the target glass 10Na2O–60P2O5–30CaO (in mol%) were investigated. The electrical properties of the glasses were studied with the impedance spectroscopy technique. At 473 K, DC conductivity values decreased from 4.21 × 10−11 to 4.21 × 10−12 S cm−1 after complete substitution of MgO for Na2O. All samples had a similar activation energy of the DC conduction process ~1.27 eV. Conduction mechanisms were found to be due to hop of ions: Na+, Mg2+, and probable H+. FTIR analysis showed that, as the Mg content increased, the Q2 unit (PO2−) shifted towards higher wavenumbers. The proportion of Q3 unit (P2O5) decreased in the glass structure. This confirmed that the replacement of Na+ by Mg2+ was accompanied by concurrent polymerization of the calcium–phosphate glass network. The biosolubility test in the phosphate-buffered saline solution showed that the magnesium addition enhanced the biosolubility properties of Na2O–CaO–P2O5 glasses by increasing their dissolution rate and supporting forming CaP-rich layers on the surface. The glass transition temperature increased, and thermal stability decreased substantially upon substitution of Na2O by MgO.

Nonflammable and thermally stable glass fiber/polyacrylate (GFP) separator for lithium-ion batteries with enhanced safety and lifespan

2021 ◽  
Vol 496 ◽  
pp. 229862
Author(s):  
Jiahui Chen ◽  
Tianxing Kang ◽  
Yan Cui ◽  
Jianjun Xue ◽  
Hanliang Xu ◽  
...  
Keyword(s):  
Glass Fiber ◽  
Lithium Ion Batteries ◽  
Lithium Ion ◽  
Thermally Stable ◽  
Stable Glass

Role of vanadium oxide on the lithium silicate glass structure and properties

2021 ◽  
Author(s):  
Anuraag Gaddam ◽  
Amarnath R. Allu ◽  
Hugo R. Fernandes ◽  
George E. Stan ◽  
Catalin C. Negrila ◽  
...  
Keyword(s):  
Vanadium Oxide ◽  
Silicate Glass ◽  
Glass Structure ◽  
Lithium Silicate ◽  
Structure And Properties ◽  
Lithium Silicate Glass
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