Utilization Of Experimental Data Research Articles

Evaluation of EC8 Part II Provisions for Bridges with Wall-Like Piers Through the Utilization of Experimental Data

For the bridges of the present article, the envelope curves of the load-deformation diagram that resulted from experimental measurements of wall specimens and the application of literature and novel equations are considered. For these load-deformation envelope curves, the behavior factors of the considered bridge models are estimated graphically by considering the envelope curves and applying the equal energy law. The aforementioned behavior factors are calculated by the use of methodology that takes into account the poor inelastic response of walls with an aspect ratio of 1.0 and 1.5. In addition, the sliding shear dominated response of the wall-like piers and the top displacement of the pier are calculated by considering the three main deformation mechanisms. Furthermore, comparative studies are performed for the definition of the plastic hinge length that should be considered for a more rational approach to the inelastic design and checking of the wall-like piers of the bridges under examination. In this way, the use of behavior factors with values higher than those determined by Eurocode 8 is justified. In the case of bridges with damaged, repaired and strengthened walls, the achieved behavior factors are significantly lower than in the case of bridges with virgin walls.

Adsorptive removal of basic yellow 2 onto reed stem and poplar leaf: A comprehensive study

The potential of reed stem (RS) and poplar leaf (PL) as low-cost, widely available agricultural wastes for adsorption of a cationic dye (basic yellow 2) from aqueous solutions has been studied. In order to optimize the biosorption process, response surface methodology (RSM) has employed. The effect of pH, temperature, dye concentration, and adsorbent dosage have determined through central composite design (CCD) and the removal efficiency of both adsorbents has compared. The interaction of variables and their impact on dye removal process was evaluated. Results indicate that for achieving the highest efficiency, RS needed an alkali environment (pH = 10.2) and a lower dosage (0.38 g), and PL needed a more moderate environment (pH = 8.88) but more dosage (0.5 g). By utilization of experimental data, the thermodynamic parameters have been calculated. Results state that adsorption by RS was endothermic (ΔH = 7.6 KJ/mol) and has a positive entropy (ΔS = 38.0 J/Kmol) while the adsorption by PL was exothermic (ΔH = −13.06 KJ/mol) and has a negative entropy (ΔS = −37.3 J/Kmol). Kinetic studies were conducted at five different concentrations. It has revealed that RS has better fitted to the intraparticle diffusion model and PL has followed the pseudo-second-order model at all dye concentrations except one. Using Temkin, Freundlich and Langmuir correlations, the best adsorption isotherm for each adsorbent has determined. FTIR analysis have indicated the most effective functional groups on the surface of absorbents that effectively play role in biosorption processes.

Lab at home: 3D printed and low-cost experiments for thermal engineering and separation processes in COVID-19 time

The SARS-CoV-2 virus pandemic has meant that face-to-face teaching activities have had to be replaced by distance learning. Experimental laboratories have been replaced, in most cases, by the utilization of experimental data or by simulations. In this work, we have designed four laboratory experiments to be conducted by students of thermal engineering and separation processes during confinement by COVID-19 at home, to maintain competence acquisition and learning outcomes. A mixed methodology of the educational models of autonomous learning and cooperative learning has been used in obtaining the experimental data and writing the laboratory report. Installations for thermal engineering have been 3D designed and printed and are aimed at studying the heat transmission by conduction and convection in heat exchangers. This work describes in detail the activities carried out and shares the files used in the 3D printing of the installations. The laboratory experiments of separation processes are focused on the removal of a dye (rhodamine B) from an aqueous solution by liquid-liquid extraction and adsorption. A survey made to the undergraduate students has confirmed that the methodology and installations designed have been satisfactory for their expectations on the acquisition of knowledge and skills in both subjects.

Modeling and prediction of fatigue life in composite materials by using singular value decomposition method

Proposing a comprehensive model to predict the fatigue life of composite structures under dynamic loading has always been a challenging problem. In this study, an attempt has been made to develop a polynomial model by utilization of experimental data together with singular value decomposition technique to estimate the fatigue life of composite materials. The model is based on a nonlinear mathematical function with effective parameters related to fatigue phenomenon in a nondimensional form. For this, four effective parameters such as cyclic stress amplitude, static strength, stress ratio, and fiber angle have been considered in modeling process. To evaluate the capability of this model a comparison has been made with some available experimental results where a good agreement is achieved. So, the obtained results demonstrate that despite system complexity and inability to extract an analytical model for estimating the fatigue life of composite materials, singular value decomposition method could be known as a useful and powerful tool for modeling.

Investigation of Dynamic Response of a Railway Bridge Equipped with a Tailored SHM System

A railway bridge has been the object of investigation in the context of structural health monitoring (SHM). The current work is focused on utilization of experimental data for refining a numerical model of the structure as well as on tests of dynamic excitations using a controlled hydraulic shaker and passing trains. The numerical model has been matched to experimental measurements using experimental modal analysis - classical and operational. The tailored SHM system for monitoring of the bridge consists of 15 piezoelectric strain sensors taking advantage of wireless communication for data transfer. Experimental responses of the bridge collected by the SHM system are confronted with the ones produced by the FE numerical model of the bridge. The long-term objective of the investigation is to elaborate a method for assessment of structural condition and prediction of remaining lifetime of the bridge.

In defense of experimental data in a relativistic milieu

The objectivity and utility of experimental data as evidential support for knowledge-claims may be found suspect when it is shown that (a) the interpretation of experimental data is inevitably complicated by social factors like experimenter effects, subject effects and demand characterics, (b) social factors which affect experimental data are themselves sensitive to societal conventions or cultural values, (c) all observations (including experimental observations) are necessarily theory-dependent, and (d) experimental data have limited generality because they are collected in artificial settings. These critiques of experimental data are answered by showing that (i) not all empirical studies are experiments, (ii) experimental methodology is developed to exclude alternate interpretations of data (including explanations in terms of social influences), (iii) theoretical disputes and their settlement take place in the context of a particular frame of reference, and (iv) objectivity can be achieved with observations neutral to the to-be-corroborated theory despite theory-dependent observations if distinctions are made (a) between prior observation and evidential observation and (b) between a to-be-corroborated theory and the theory underlying the identity of evidential response.

The Utilization of Experimental Data in Modelling Hydraulic Single Stage Pressure Control Valves

Low-order nonlinear models for single stage pressure relief and pressure reducing valves are developed and subjected to experimental verification. The form of both models is postulated by an appeal to physical principles, but the parameter values are identified with the help of simple numerical methods using measured characteristic curves.

Some problems in the application of statistical dynamics to shells manufactured from fibrous composites

On the basis of a statistical approach presupposing direct utilization of experimental data produced in modelling operations, a procedure is proposed for computational estimates on composite materials in which allowance is made for the initial defects, the variable properties of the material, and the conditions of use (physical medium). Experimental data on Plexiglas shells which confirm the practical applicability of the procedure are given. Questions relating to the design of tests on composite shells are discussed.

Equations of state of condensed media

We discuss a method for constructing the complete equation of state of a condensed medium thermodynamically, this method being based on the utilization of experimental data on shock compression and on the second law of thermodynamics. Determination of the accuracy of the solution so obtained, so far as its dependence on experimental error connected with the dynamical experiments and initial conditions was concerned, was carried out by means of statistical tests (Monte Carlo). The method is free from restricting assumptions as to the properties and nature of the medium under investigation. In the present paper, equations of state for W, Cu, and LiF are constructed. The results obtained are compared with experimental results and with equations of state based on models.