scholarly journals Practice on the Watershed Hydrological Experimental System Reconciling Deterministic and Stochastic Subjects Based on the System Complexity: 1. Theoretical Study

2018 ◽  
Author(s):  
Wei-Zu Gu ◽  
Jiu-Fu Liu ◽  
Ai-Min Liao ◽  
Niu Wang ◽  
Jia-Ju Lu ◽  
...  
Keyword(s):  
Theoretical Study ◽  
Experimental System ◽  
System Complexity

Natural Convection in a Rectangular Porous Cavity With One Permeable Endwall

1983 ◽  
Vol 105 (4) ◽  
pp. 803-808 ◽  
Author(s):  
M. Haajizadeh ◽  
C. L. Tien
Keyword(s):  
Theoretical Study ◽  
Numerical Solutions ◽  
Constant Pressure ◽  
Experimental System ◽  
Governing Equations ◽  
Porous Cavity ◽  
Steady State Temperature ◽  
Shallow Cavity ◽  
Higher Temperature ◽  
Water Saturated

This paper describes a theoretical and experimental study of two-dimensional, buoyancy-driven flow in a rectangular porous cavity with one permeable endwall. Connected to a constant temperature tank, the permeable end allows for natural recharge and discharge of the saturating fluid. The other vertical endwall is impermeable and maintained at a constant but higher temperature, thus inducing a buoyancy-driven flow. The theoretical study includes an asymptotic analysis developed for a shallow cavity with one permeable endwall and the numerical solutions of the power-law difference representation of the full governing equations. The experimental system consists of water-saturated glass beads packed in a rectangular cavity with a length-to-height aspect ratio of 3.17, for which the Rayleigh number can vary up to 120. Measurements were made of the steady-state temperature distribution in the cavity and the heat transfer rate from the impermeable endwall. It is shown that the constant pressure and temperature assumptions at the permeable wall, as employed in the theoretical analysis, satisfactorily predict the experimental data. Results are also compared with those existing in the literature.

scholarly journals Study on the Viscoelasticity Measurement of Materials Based on Surface Reflected Waves

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1875 ◽  
Author(s):  
Jun-jie Chang ◽  
Yuan-yuan Li ◽  
Xue-feng Zeng ◽  
Hai-ying Zhong ◽  
Tao-lei Wan ◽  
...  
Keyword(s):  
Theoretical Study ◽  
Loss Modulus ◽  
Experimental System ◽  
Ultrasonic Waves ◽  
Reflection Method ◽  
Multiple Reflections ◽  
Reflected Waves ◽  
Surface Reflection ◽  
Overall Efficiency

The reflected waves received from ultrasonic waves propagating in materials contain information that constitutes the physical properties, material composition, defects, and degradation states. When measuring the dynamic viscoelasticity, the traditional bottom reflection method (BRM) cannot be used to measure the bottom irregular samples. In this paper, the storage modulus, loss modulus, and loss tangent are extracted by the surface reflection method (SRM) to evaluate the elastomer sample viscoelasticity. A theoretical study on the phase change caused by multiple reflections in the case of non-thin layer coupling is conducted. Based on this research, the experimental system is built. The results show that considering the thickness of the coupling layer can optimize the determination of viscoelasticity and reduce the error of the viscoelastic evaluation results of an elastomer with the traditional BRM. Finally, based on the principle of the SRM, the density of the elastomers is measured, and the feasibility and overall efficiency of this method are verified by experiments.

Detecting Random Responses in a Personality Scale Using IRT-Based Person-Fit Indices

2019 ◽  
Vol 35 (1) ◽  
pp. 126-136 ◽  
Author(s):  
Tour Liu ◽  
Tian Lan ◽  
Tao Xin
Keyword(s):  
Experimental System ◽  
Real Data ◽  
Fit Indices ◽  
Random Response ◽  
Person Fit ◽  
Index Method ◽  
Single Person ◽  
Person Fit Index ◽  
Random Responses ◽  
Response Behaviors

Abstract. Random response is a very common aberrant response behavior in personality tests and may negatively affect the reliability, validity, or other analytical aspects of psychological assessment. Typically, researchers use a single person-fit index to identify random responses. This study recommends a three-step person-fit analysis procedure. Unlike the typical single person-fit methods, the three-step procedure identifies both global misfit and local misfit individuals using different person-fit indices. This procedure was able to identify more local misfit individuals than single-index method, and a graphical method was used to visualize those particular items in which random response behaviors appear. This method may be useful to researchers in that it will provide them with more information about response behaviors, allowing better evaluation of scale administration and development of more plausible explanations. Real data were used in this study instead of simulation data. In order to create real random responses, an experimental test administration was designed. Four different random response samples were produced using this experimental system.

Adsorption of H2O and H2S on the (100) surface of silicon. A theoretical study

1987 ◽  
Vol 84 ◽  
pp. 799-803 ◽  
Author(s):  
Vincenzo Barone ◽  
Francesco Lelj ◽  
Nino Russo ◽  
Marirosa Toscano
Keyword(s):  
Theoretical Study
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