Response of Viscoelastic Plate to Impact

2007 ◽  
Vol 130 (1) ◽  
Author(s):  
D. Ingman ◽  
J. Suzdalnitsky
Keyword(s):  
Initial Conditions ◽  
Viscoelastic Plate ◽  
Servo Control ◽  
Order Function ◽  
Damping Decrement ◽  
Vibration Process ◽  
Alternative Approaches ◽  
The Impact ◽  
Fractional Differentiation Operator

Organization of product tests in the microelectronic and optical-electronic industries by the impact method is considered. Two mathematical models: a circular plate under dynamic loading with predetermined initial conditions, and contact interaction of a falling mass and a barrier, are examined. The deflection function, curvature, and acceleration are determined. As the series for these characteristics may prove divergent, the problem is to secure sufficiently reliable results. The method of impact mechanics permits determination of the duration and force of the impact, estimation of the total energy of each mode in the expansion of the deflection function and preclusion of divergent series when determining the plate acceleration and curvature during the vibration process. In parallel, viscoelasticity is simulated with the aid of a fractional-differentiation operator, certain features of which are discussed. Representation of this operator with time-dependent order by ones with constant orders is considered. Three alternative approaches for determination of the eigenfrequency and damping decrement of a vibration process are examined. In particular, a method for calculating these characteristics under conditions of time-dependence and servo control of the order function is proposed.

Refined Modeling of Projectile Impact Onto Submerged Structure

2008 ◽  
Author(s):  
Justin Onisoru ◽  
Ovidiu Coman ◽  
Paul Wilson ◽  
George Thomas
Keyword(s):  
Strain Rate ◽  
Structural Integrity ◽  
Initial Conditions ◽  
Safety Issue ◽  
Constant Strain Rate ◽  
Strain Curve ◽  
Material Behavior ◽  
Spent Fuel ◽  
The Impact

Structural integrity of spent fuel racks is a critical safety issue in nuclear power stations. The standard approach of evaluating the effects of an impact projectile on a submerged structure, which constitute the start point of the current study, involves three main steps: determination of the conditions just prior to the impact (that are considered as initial conditions for the analysis), setting the mechanism of transferring energy from the projectile to the target structure, and determining how that energy is absorbed by the impacted structure. Usually, the dynamics of the projectile are ideally considered, the influence of the fluid presence is restricted to the determination of the impact velocity and strain rate dependency is limited to choosing a true stress vs. strain curve corresponding to some constant strain rate. Starting from the standard engineering approach, the authors have refined the model considering more realistic dynamics of the projectile, extending the influence of the fluid to the entire analysis and using a more accurate strain rate dependant material behavior. Explicit Finite Element analyses are used in order to incorporate the desired effects.

scholarly journals EFFECTS OF STANDARD AND MODIFIED GRAVITY ON INTERPLANETARY RANGES

2011 ◽  
Vol 20 (02) ◽  
pp. 181-232 ◽  
Author(s):  
L. IORIO
Keyword(s):  
Initial Conditions ◽  
A Priori ◽  
Earth Planet ◽  
General Relativistic ◽  
Heliocentric Orbits ◽  
Newtonian Constant ◽  
The Impact ◽  
Very High ◽  
Better Than

We numerically investigate the impact on the two-body range of several Newtonian and non-Newtonian dynamical effects for some Earth-planet (Mercury, Venus, Mars, Jupiter, Saturn) pairs, in view of the expected cm-level accuracy in some future planned or proposed interplanetary ranging operations. The general relativistic gravitomagnetic Lense–Thirring effect should be modeled and solved for in future accurate ranging tests of Newtonian and post-Newtonian gravity, because it falls within their measurability domain. It could a priori "imprint" the determination of some of the target parameters of the tests considered. Moreover, the ring of the minor asteroids, Ceres, Pallas, Vesta (and also many other asteroids if Mars is considered) and the trans-Neptunian objects (TNOs) act as sources of nonnegligible systematic uncertainty on the larger gravitoelectric post-Newtonian signals from which it is intended to determine the parameters γ and β of the parametrized post-Newtonian (PPN) formalism with very high precision (several orders of magnitude better than the current 10-4–10-5levels). Also, other putative, nonconventional gravitational effects, like a violation of the strong equivalence principle (SEP), a secular variation of the Newtonian constant of gravitation G, and the Pioneer anomaly, are considered. The presence of a hypothetical, distant planetary-sized body X could be detectable with future high-accuracy planetary ranging. Our analysis can, in principle, be extended to future interplanetary ranging scenarios in which one or more spacecrafts in heliocentric orbits are involved. The impact of fitting the initial conditions, and of the noise in the observations, on the actual detectability of the dynamical signatures investigated, which may be partly absorbed in the estimation process, should be quantitatively addressed in further studies.

scholarly journals A Statistical Methodology for Determination of Safety Systems Actuation Setpoints Based on Extreme Value Statistics

2008 ◽  
Vol 2008 ◽  
pp. 1-10 ◽  
Author(s):  
D. R. Novog ◽  
P. Sermer
Keyword(s):  
Nuclear Reactor ◽  
Initial Conditions ◽  
General Concept ◽  
Extreme Value Statistics ◽  
Plant Responses ◽  
True Value ◽  
Time Changes ◽  
Safety Systems ◽  
The Impact

This paper provides a novel and robust methodology for determination of nuclear reactor trip setpoints which accounts for uncertainties in input parameters and models, as well as accounting for the variations in operating states that periodically occur. Further it demonstrates that in performing best estimate and uncertainty calculations, it is critical to consider the impact of all fuel channels and instrumentation in the integration of these uncertainties in setpoint determination. This methodology is based on the concept of a true trip setpoint, which is the reactor setpoint that would be required in an ideal situation where all key inputs and plant responses were known, such that during the accident sequence a reactor shutdown will occur which just prevents the acceptance criteria from being exceeded. Since this true value cannot be established, the uncertainties in plant simulations and plant measurements as well as operational variations which lead to time changes in the true value of initial conditions must be considered. This paper presents the general concept used to determine the actuation setpoints considering the uncertainties and changes in initial conditions, and allowing for safety systems instrumentation redundancy. The results demonstrate unique statistical behavior with respect to both fuel and instrumentation uncertainties which has not previously been investigated.

scholarly journals FEATURES OF TRANSIENT RESEARCH IN THREE-PHASE HIGH-VOLTAGE POWER TRANSMISSION CABLE LINES

2021 ◽  
pp. 135-148
Author(s):  
Vadim Lobodzinskiy ◽  
Valeriy Chybelis ◽  
Oleg Petruchenko ◽  
Olga Illina ◽  
Yuliya Chunyak ◽  
...  
Keyword(s):  
Power Transmission ◽  
Initial Conditions ◽  
Current Trend ◽  
Electric Circuit ◽  
Distributed Parameters ◽  
Three Phase ◽  
Cable Lines ◽  
The Impact ◽  
External Connections

The methods of analysis of transients in three-phase circuits with distributed parameters and interphase connections are considered on the basis of representation of such circuits by multipoles, finding their corresponding concentrated parameters and determination of boundary and initial conditions of transients. The formulation of this scientific problem is justified by the current trend in theoretical electrical engineering to consider multiphase circuits as a series-parallel connection of different n-poles, which improves the calculation of transient electromagneticprocesses in multiphase circuits with distributed parameters and interphase connections. Using thetheory of multipoles allows us to represent the elements of the electric circuit by macromodels thatreflect their external connections and the impact on the rest of the circuit. The main difficulty inapplying this principle is to resolve emerging electromagnetic bonds.

Assessment of sensitivity of the efficiency of regional tax spending towards investment attractiveness of the types of economic activity carried out by the residents of advanced development territory

2020 ◽  
pp. 98-110
Author(s):  
Evgeniya Mikhailovna Popova ◽  
Guzel Mukhtarovna Guseinova ◽  
Sergei Borisovich Milov
Keyword(s):  
Economic Activity ◽  
Socioeconomic Development ◽  
Federal District ◽  
Tax Incentives ◽  
Capital Investments ◽  
The Subject ◽  
Investment Process ◽  
The Impact ◽  
Advanced Development

The deficit of subnational budgets and deceleration capital investments in multiple Russian regions increase the relevance of research aimed at improvement of tax incentivizing practice of the regional investment process. The studies focused on determination of the impact of socioeconomic and institutional factors upon the efficiency of investment tax expenses obtained wide circulation within the foreign scientific literature. The subject of this article is the assessment of sensitivity of the efficiency of regional tax expanses towards investment attractiveness of the types of economic activity carried out by the residents of territories of advanced socioeconomic development, created in the subjects of Far Easter Federal District. The scientific novelty and practical values of this research consists in substantiation of the reasonableness of assessment of investment attractiveness of the types of economic activity that are stimulated by tax incentives. Methodology for assessing investment attractiveness is proposed and tested. The conclusion is made that in case of low investment attractiveness of the type of economic activity, which was planned to support by tax incentives, it is required to conduct and additional analysis to avoid unjustified tax expanses.

Method development for the determination of textural properties of sugar beet roots

2019 ◽  
pp. 392-400 ◽  
Author(s):  
Gunnar Kleuker ◽  
Christa M. Hoffmann
Keyword(s):  
Sugar Beet ◽  
Compression Test ◽  
Storage Period ◽  
Textural Properties ◽  
Small Sample ◽  
Root Tip ◽  
Flexural Test ◽  
Sample Distribution ◽  
The Impact

The harvest of sugar beet leads to root tip breakage and surface damage through mechanical impacts, which increase storage losses. For the determination of textural properties of sugar beet roots with a texture analyzer a reliable method description is missing. This study aimed to evaluate the impact of washing, soil tare, storage period from washing until measurement, sample distribution and number of roots on puncture and compression measurements. For this purpose, in 2017 comprehensive tests were conducted with sugar beet roots grown in a greenhouse. In a second step these tests were carried out with different Beta varieties from a field trial, and in addition, a flexural test was included. Results show that the storage period after washing and the sample distribution had an influence on the puncture and compression strength. It is suggested to wash the roots by hand before the measurement and to determine the strength no later than 48 h after washing. For reliable and comparable results a radial distribution of measurement points around the widest circumference of the root is recommended for the puncture test. The sample position of the compression test had an influence on the compressive strength and therefore, needs to be clearly defined. For the puncture and the compression test it was possible to achieve stable results with a small sample size, but with increasing heterogeneity of the plant stand a higher number of roots is required. The flexural test showed a high variability and is, therefore, not recommended for the analysis of sugar beet textural properties.

Development and Validation of an LC-MS/MS Method for Simultaneous Determination of Canagliflozin and Metformin HCl in Rat Plasma and its Application

2020 ◽  
Vol 16 (6) ◽  
pp. 752-762
Author(s):  
Vivek Nalawade ◽  
Vaibhav A. Dixit ◽  
Amisha Vora ◽  
Himashu Zade
Keyword(s):  
Internal Standard ◽  
Rat Plasma ◽  
Precipitation Method ◽  
Herbal Extracts ◽  
One Step ◽  
Precision And Accuracy ◽  
Development And Validation ◽  
The Impact ◽  
Metformin Hcl

Background: Food and herbal extracts rich in Quercetin (QRT) are often self-medicated by diabetics and can potentially alter the pharmacokinetics (PK) of Metformin HCl (MET) and Canagliflozin (CNG) leading to food or herb-drug interactions and reduced therapeutic efficacy. However, the impact of these flavonoids on the pharmacokinetic behaviour of MET and CNG is mostly unknown. Methods: A simple one-step protein precipitation method was developed for the determination of MET and CNG from rat plasma. The mobile phase chosen was MeOH 65% and 35% water containing 0.1% formic acid at a flow rate of 1mL/min. Results: The retention time of MET, internal standard (Valsartan) and CNG was 1.83, 6.2 and 8.2 min, respectively. The method was found to be linear in the range of 200 - 8000 ng/mL for CNG and 100 = 4000 ng/ml for MET. Precision and accuracy of the method were below 20% at LLOQ and below 15% for LQC, MQC, and HQC. Conclusion: The method was successfully applied for the determination of PK of MET and CNG by using 100 μL of rat plasma. QRT co-administration affects the PK parameters of MET and CNG. This alteration in PK parameters might be of significant use for clinicians and patients.

The Microeconomics of Product Innovation

2018 ◽  
Author(s):  
Paul Stoneman ◽  
Eleonora Bartoloni ◽  
Maurizio Baussola
Keyword(s):  
Product Innovation ◽  
New Products ◽  
Goods And Services ◽  
Product Innovations ◽  
Microeconomic Analysis ◽  
Prime Objective ◽  
Price Measurement ◽  
The Impact

The prime objective of this book is the use microeconomic analysis to guide and provide insight into the generation and adoption of new products. Taking an approach that uses minimal formal mathematics, the volume initially addresses questions of definitions, sources, and extent of product innovation, differentiating between goods and services; hard and soft innovations; horizontal and vertical innovations; original, new to market, and new to firm innovations. The sources of product innovations (e.g. R&D, design, and creativity) are explored empirically, and the extent of such innovations is then pursued using survey and other data. Three chapters are devoted to the theoretical analysis of the demand for and supply of new products and to the determination of firms’ decisions to undertake product innovation. Later chapters encompass empirical evidence on the determination of the extent of product innovation, the diffusion of such innovation, the impact of product innovation on firm performance, price measurement, and welfare, while the final chapter addresses policy issues.

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