scholarly journals Modeling Interactions among Migration, Growth and Pressure in Tumor Dynamics

Mathematics ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1376
Author(s):  
Beatriz Blanco ◽  
Juan Campos ◽  
Juan Melchor ◽  
Juan Soler
Keyword(s):  
Experimental Data ◽  
Numerical Approach ◽  
Point Of View ◽  
Local Growth ◽  
Cell Dynamics ◽  
Growth Pressure ◽  
Propagation Front ◽  
Diffusion Phenomena ◽  
Global Understanding ◽  
Dispersion Terms

What are the biomechanical implications in the dynamics and evolution of a growing solid tumor? Although the analysis of some of the biochemical aspects related to the signaling pathways involved in the spread of tumors has advanced notably in recent times, their feedback with the mechanical aspects is a crucial challenge for a global understanding of the problem. The aim of this paper is to try to illustrate the role and the interaction between some evolutionary processes (growth, pressure, homeostasis, elasticity, or dispersion by flux-saturated and porous media) that lead to collective cell dynamics and defines a propagation front that is in agreement with the experimental data. The treatment of these topics is approached mainly from the point of view of the modeling and the numerical approach of the resulting system of partial differential equations, which can be placed in the context of the Hele-Shaw-type models. This study proves that local growth terms related to homeostatic pressure give rise to retrograde diffusion phenomena, which compete against migration through flux-saturated dispersion terms.

Research Regarding the Effects of 120 mm HE Mortar Bombs on Advanced Materials

2021 ◽  
Vol 42 ◽  
pp. 128-134
Author(s):  
Daniela Pintilie ◽  
Iuliana Florina Pană ◽  
Adrian Malciu ◽  
Constantin Puică ◽  
Cristina Pupăză
Keyword(s):  
Experimental Data ◽  
Numerical Model ◽  
Initial Velocity ◽  
High Explosive ◽  
Numerical Approach ◽  
Advanced Materials ◽  
Physical Mechanisms ◽  
Shock Wave Generation ◽  
3D Numerical Model ◽  
Experimental Trials

High Explosive Mortar bombs are used on the battlefield for destroying the manpower, non-armoured equipment and shelters. The paper describes an original experimental and numerical approach regarding the potential threats caused by the detonation of 120 mm HE mortar bombs. The evaluation of the bomb effect presumes the fulfillment of experimental trials that focus on two physical mechanisms which appear after the detonation of the cased high explosive. These mechanisms are the shock wave generation and the fragments propulsion, which were also studied by a numerical model that provides results over the bomb fragmentation mode. The novelty of the paper consists in the calibrated 3D numerical model confirmed by the experimental data, which provides information over the fragmentation process of the case and the initial velocity of its fragments, proving that the main threat of this type of ammunition is the effect through metal fragments. The results of numerical simulation and experimental data are used for their comparative analysis and the assessment of the phenomena.

The Mechanical Modeling of Oxygen-Containing Precipitates in Silicon Wafers on Different Stages of the Getter Formation Process

2011 ◽  
Vol 178-179 ◽  
pp. 483-488
Author(s):  
Pavel S. Shushpannikov ◽  
Robert V. Goldstein ◽  
Konstantin Ustinov
Keyword(s):  
Experimental Data ◽  
Silicon Wafer ◽  
Formation Process ◽  
Strain State ◽  
Spherical Shape ◽  
Point Of View ◽  
Dislocation Loops ◽  
Mechanical Modeling ◽  
Silicon Matrix ◽  
Spheroidal Inclusion

The behavior of the oxygen-containing precipitate in silicon wafer on different stages of the getter formation process is considered from the mechanical point of view. The precipitate is modeled as a spheroidal inclusion undergoing inelastic eigenstrains in an anisotropic silicon matrix. The stress-strain state in the precipitate and matrix is calculated within the framework of the model. An energetic criterion of breaking the spherical shape by the coherent precipitates is obtained and analyzed. Criteria of the formation and onset of motion of the dislocation loops in the vicinity of the precipitate are also proposed. The obtained results are compared with the available experimental data.

scholarly journals A Numerical Approach for Sound Quality of Vehicle Doors

2020 ◽  
Vol 25 (1) ◽  
pp. 9-16
Author(s):  
Erkut Yalçın ◽  
Halil Bilal ◽  
Ayhan Yağcı ◽  
Haluk Erol
Keyword(s):  
Sound Pressure ◽  
Sound Quality ◽  
Numerical Approach ◽  
Design Sensitivity ◽  
Point Of View ◽  
Vehicle Body ◽  
Fem Model ◽  
Body Development ◽  
Design Variables

A Vibro-Acoustic Finite Element Method (FEM) model capable of calculating the transient sound pressure generated by the door slam of a vehicle was developed in this study. A design sensitivity analysis (DSA) was performed for investigating the effects of major design variables on the related sound quality metrics. The methodology was developed using a sedan-car and its FEM model. This paper shows that a Computer Aided Engineering (CAE) model can be used as a rather powerful tool for giving design change decisions for the door components from sound quality point of view during vehicle body development according to psychoacoustic parameters.

scholarly journals РІВНІ ІНШОМОВНОЇ КОМПЕТЕНТНОСТІ МАЙБУТНІХ ФАХІВЦІВ СОЦІАЛЬНОЇ СФЕРИ

2019 ◽  
pp. 16-20
Author(s):  
Павелків К. М.
Keyword(s):  
Experimental Data ◽  
Foreign Language ◽  
Experimental Research ◽  
Point Of View ◽  
Language Training ◽  
Self Assessment ◽  
Language Competence ◽  
Social Sphere ◽  
Competence Level ◽  
The University

The article presents the results of experimental research of foreign language competence level of future social sphere specialist. The experimental data are compared with the results of students’ under study self-assessment of their foreign language competence level. The article shows the results of the influence of methodological system of foreign language training of future social sphere specialist on the increase of the level of foreign language competence among participants of experimental groups. Creative, medium, satisfactory and unsatisfactory levels of foreign language competence of future social sphere specialist are characterized from the point of view students’ reflexion. The research approves the effectiveness of pedagogical influences introduced at the forming stage of the experiment through approbation of the author’s methodical system of foreign language training in the university.

Software Tool for Assessment of Complexity and Variability in Physiological Signals of Respiration

2011 ◽  
Vol 1 (2) ◽  
pp. 28-53
Author(s):  
Ireneusz Jablonski ◽  
Kamil Subzda ◽  
Janusz Mroczka
Keyword(s):  
Complex System ◽  
Experimental Data ◽  
Time Series ◽  
Data Analysis ◽  
Input Signal ◽  
Software Tool ◽  
Point Of View ◽  
Software Implementation ◽  
Physiological Signals ◽  
Event Time

In this paper, the authors examine software implementation and the initial preprocessing of data and tools during the assessment of the complexity and variability of long physiological time-series. The algorithms presented advance a bigger Matlab library devoted to complex system and data analysis. Commercial software is unavailable for many of these functions and is generally unsuitable for use with multi-gigabyte datasets. Reliable inter-event time extraction from input signal is an important step for the presented considerations. Knowing the distribution of the inter-event time distances, it is possible to calculate exponents due to power-law scaling. From a methodology point of view, simulations and considerations with experimental data supported each stage of the work presented. In this paper, initial calibration of the procedures with accessible data confirmed assessments made during earlier studies, which raise objectivity of measurements planned in the future.

scholarly journals Considerations for the design of polymeric biodegradable products

2013 ◽  
Vol 33 (4) ◽  
pp. 293-302 ◽  
Author(s):  
André C. Vieira ◽  
Rui M. Guedes ◽  
Volnei Tita
Keyword(s):  
Experimental Data ◽  
Constitutive Models ◽  
Tensile Tests ◽  
Failure Criteria ◽  
Numerical Approach ◽  
Life Cycles ◽  
Strength Failure ◽  
First Order Kinetics ◽  
User Material Subroutine ◽  
Degradation Time

Abstract Several biodegradable polymers are used in many products with short life cycles. The performance of a product is mostly conditioned by the materials selection and dimensioning. Strength, maximum strain and toughness will decrease along its degradation, and it should be enough for the predicted use. Biodegradable plastics can present short-term performances similar to conventional plastics. However, the mechanical behavior of biodegradable materials, along the degradation time, is still an unexplored subject. The maximum strength failure criteria, as a function of degradation time, have traditionally been modeled according to first order kinetics. In this work, hyperelastic constitutive models are discussed. An example of these is shown for a blend composed of poly(L-lactide) acid (PLLA) and polycaprolactone (PCL). A numerical approach using ABAQUS is presented, which can be extended to other 3D geometries. Thus, the material properties of the model proposed are automatically updated in correspondence to the degradation time, by means of a user material subroutine. The parameterization was achieved by fitting the theoretical curves with the experimental data of tensile tests made on a PLLA-PCL blend (90:10) for different degradation times. The results obtained by numerical simulations are compared to experimental data, showing a good correlation between both results.

scholarly journals Artificial Neural Networks Application in Modal Analysis of Tires

2013 ◽  
Vol 13 (5) ◽  
pp. 273-278 ◽  
Author(s):  
P. Koštial ◽  
Z. Jančíková ◽  
D. Bakošová ◽  
J. Valíček ◽  
M. Harničárová ◽  
...  
Keyword(s):  
Experimental Data ◽  
Neural Networks ◽  
Artificial Neural Networks ◽  
Modal Analysis ◽  
Speckle Pattern ◽  
Point Of View ◽  
Electronic Speckle Pattern Interferometry ◽  
Data Sets ◽  
Artificial Neural

Abstract The paper deals with the application of artificial neural networks (ANN) to tires’ own frequency (OF) prediction depending on a tire construction. Experimental data of OF were obtained by electronic speckle pattern interferometry (ESPI). A very good conformity of both experimental and predicted data sets is presented here. The presented ANN method applied to ESPI experimental data can effectively help designers to optimize dimensions of tires from the point of view of their noise.

A Numerical Model for Oil Film Flow in an Aero-Engine Bearing Chamber and Comparison With Experimental Data

2004 ◽  
Author(s):  
Mark Farrall ◽  
Kathy Simmons ◽  
Stephen Hibberd ◽  
Philippe Gorse
Keyword(s):  
Experimental Data ◽  
Boundary Conditions ◽  
Roller Bearing ◽  
Numerical Approach ◽  
Oil Droplets ◽  
Two Phase ◽  
Oil Film ◽  
Aero Engine ◽  
The Impact ◽  
Engine Bearing

The work presented forms part of an on-going investigation, focusing on modelling the motion of a wall oil film present in a bearing chamber and comparison with existing experimental data. The film is generated through the impingement of oil droplets shed from a roller bearing. Momentum resulting from the impact of oil droplets, interfacial shear from the airflow, and gravity cause the film to migrate around the chamber. Oil and air exit the chamber at scavenge and vent ports. A previously reported numerical approach to the simulation of steady-state two-phase flow in a bearing chamber, that includes in-house sub-models for droplet-film interaction and oil film motion, has been extended. This paper includes the addition of boundary conditions for the vent and scavenge together with a comparison to experimental results obtained from ITS, University of Karlsruhe. The solution is found to be sensitive to the choice of boundary conditions applied to the vent and scavenge.

scholarly journals High-Level Rovibrational Calculations on Ketenimine

2021 ◽  
Vol 8 ◽  
Author(s):  
Martin Tschöpe ◽  
Benjamin Schröder ◽  
Sebastian Erfort ◽  
Guntram Rauhut
Keyword(s):  
Experimental Data ◽  
Potential Energy Surfaces ◽  
Point Of View ◽  
Cluster Approximation ◽  
Time Data ◽  
Biologically Relevant ◽  
Star Forming ◽  
Variational Calculations ◽  
Explicitly Correlated ◽  
High Level

From an astrochemical point of view ketenimine (CH2CNH) is a complex organic molecule (COM) and therefore likely to be a building block for biologically relevant molecules. Since it has been detected in the star-forming region Sagittarius B2(N), it is of high relevance in this field. Although experimental data are available for certain bands, for some energy ranges such as above 1200 cm−1 reliable data virtually do not exist. In addition, high-level ab initio calculations are neither reported for ketenimine nor for one of its deuterated isotopologues. In this paper, we provide for the first time data from accurate quantum chemical calculations and a thorough analysis of the full rovibrational spectrum. Based on high-level potential energy surfaces obtained from explicitly correlated coupled-cluster calculations including up to 4-mode coupling terms, the (ro)vibrational spectrum of ketenimine has been studied in detail by variational calculations relying on rovibrational configuration interaction (RVCI) theory. Strong Fermi resonances were found for all isotopologues. Rovibrational infrared intensities have been obtained from dipole moment surfaces determined from the distinguishable cluster approximation. A comparison of the spectra of the CH2CNH molecule with experimental data validates our results, but also reveals new insight about the system, which shows very strong Coriolis coupling effects.

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