Flavor Release from Composite Dairy Gels: A Comparison between Model Predictions and Time-Intensity Experimental Studies

2000 ◽  
pp. 381-394 ◽  
Author(s):  
I. P. T. Moore ◽  
T. M. Dodds ◽  
R. P. Turnbull ◽  
R. A. Crawford
Keyword(s):  
Experimental Studies ◽  
Flavor Release ◽  
Model Predictions

Ball Grid Array Thermomechanical Response During Reflow Assembly

1996 ◽  
Vol 118 (4) ◽  
pp. 214-222 ◽  
Author(s):  
T. E. Voth ◽  
T. L. Bergman
Keyword(s):  
Process Model ◽  
Experimental Studies ◽  
Ball Grid Array ◽  
Mechanical Processing ◽  
Processing Conditions ◽  
System Behavior ◽  
Reflow Soldering ◽  
Thermomechanical Response ◽  
Model Predictions ◽  
Representative System

The thermomechanical response of ball-grid array assemblies during reflow soldering is considered here. Experiments are performed to investigate the thermomechanical response of a representative system and the results are used to validate a numerical model of system behavior. The conclusions drawn from the experimental studies are used to guide development of a process model capable of describing more realistic BGA soldering scenarios. Process model predictions illustrate the system’s thermomechanical response to thermal and mechanical processing conditions, as well as component properties. High thermal conductivity assemblies show the greatest sensitivity to mechanical loading conditions.

Experimental Studies on Attenuation of Rotor-Stator Dynamics: Effects of High-Frequency Inclusion and Annular Fluid

2018 ◽  
Author(s):  
Meryem Kanzari ◽  
Mohammed AlQaradawi ◽  
Balakumar Balachandran
Keyword(s):  
High Frequency ◽  
Complex Dynamics ◽  
Experimental Studies ◽  
Flexible Rotor ◽  
Flexible Rotors ◽  
Speed Modulation ◽  
Model Predictions ◽  
Drive Speed ◽  
The Stability ◽  
Three Degree Of Freedom

Flexible, rotating structures can experience complex dynamics, when torsional and lateral motions are involved. Oilwell drill strings form one example of such structures. In the present study, the authors investigate the influence of sinusoidal drive speed modulation on whirling motions of flexible rotors with contact interactions. For two types of drilling-like operations, one with drill mud and another without drill mud, the stability of motions is studied. A laboratory-scale drill rig is used to study the dynamics of a flexible rotor, which is driven at one end and housed within a stator at the other end. Experimental results are presented and discussed for different drive speeds. The findings suggest that the addition of drill mud in the annular space between the rotor and stator along with high-frequency modulation in the drive input helps attenuate lateral motions. The torsional motions appear to be influenced more by the high-frequency drive speed modulation. A three-degree-of-freedom model has been constructed to study lateraltorsional dynamics of a rotor-stator system. The model predictions are compared with the experimental data. The findings of this work have relevance for constructing practical solutions to control whirl dynamics of flexible rotors such as drill strings.

A Computational and Experimental Study of Cold Rolling of Aluminum Alloys With Edge Cracking

2004 ◽  
Vol 126 (1) ◽  
pp. 74-82 ◽  
Author(s):  
S. Ghosh ◽  
M. Li ◽  
D. Gardiner
Keyword(s):  
Finite Element ◽  
Aluminum Alloys ◽  
Cold Rolling ◽  
Experimental Studies ◽  
Rolling Process ◽  
Rolled Strip ◽  
Damage Models ◽  
Friction Laws ◽  
Model Predictions ◽  
Edge Cracking

This paper identifies various modeling issues that are necessary for successful simulation of the cold rolling process by comparing it with experiments on aluminum alloys. It combines considerable experimental studies with finite element simulations using the ABAQUS/Explicit commercial finite element code to identify and evaluate modeling parameters, such as the material properties and friction laws. Damage models are incorporated in the numerical simulations by using plasticity with damage variables e.g., the Gurson-Tvergaard model with evolving porosity and Cockcroft-Latham with damage in terms of plastic work. The 3D model predictions are compared with predictions from 2D models to understand the limitations of 2D simulations in predicting the stresses, strains and evolving damage in the rolled strip.

scholarly journals Bioactivation of Isoxazole-Containing Bromodomain and Extra-Terminal Domain (BET) Inhibitors

Metabolites ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 390
Author(s):  
Noah R. Flynn ◽  
Michael D. Ward ◽  
Mary A. Schleiff ◽  
Corentine M. C. Laurin ◽  
Rohit Farmer ◽  
...  
Keyword(s):  
Experimental Studies ◽  
Reactive Metabolites ◽  
Neural Models ◽  
Quinone Methides ◽  
Coupled Modeling ◽  
Bet Inhibitor ◽  
Bet Inhibitors ◽  
Depth Analysis ◽  
Model Predictions ◽  
Drug Leads

The 3,5-dimethylisoxazole motif has become a useful and popular acetyl-lysine mimic employed in isoxazole-containing bromodomain and extra-terminal (BET) inhibitors but may introduce the potential for bioactivations into toxic reactive metabolites. As a test, we coupled deep neural models for quinone formation, metabolite structures, and biomolecule reactivity to predict bioactivation pathways for 32 BET inhibitors and validate the bioactivation of select inhibitors experimentally. Based on model predictions, inhibitors were more likely to undergo bioactivation than reported non-bioactivated molecules containing isoxazoles. The model outputs varied with substituents indicating the ability to scale their impact on bioactivation. We selected OXFBD02, OXFBD04, and I-BET151 for more in-depth analysis. OXFBD’s bioactivations were evenly split between traditional quinones and novel extended quinone-methides involving the isoxazole yet strongly favored the latter quinones. Subsequent experimental studies confirmed the formation of both types of quinones for OXFBD molecules, yet traditional quinones were the dominant reactive metabolites. Modeled I-BET151 bioactivations led to extended quinone-methides, which were not verified experimentally. The differences in observed and predicted bioactivations reflected the need to improve overall bioactivation scaling. Nevertheless, our coupled modeling approach predicted BET inhibitor bioactivations including novel extended quinone methides, and we experimentally verified those pathways highlighting potential concerns for toxicity in the development of these new drug leads.

Thermospheric heating away from the auroral oval during geomagnetic storms

1992 ◽  
Vol 70 (7) ◽  
pp. 544-552 ◽  
Author(s):  
A. G. Burns ◽  
T. L. Killeen ◽  
R. G. Roble
Keyword(s):  
Geomagnetic Storms ◽  
Preliminary Investigation ◽  
Experimental Studies ◽  
Auroral Oval ◽  
Long Tail ◽  
Temperature Changes ◽  
Model Predictions ◽  
Latitude Region ◽  
Region Ii ◽  
Iv Model

Model predictions indicate that the high-latitude thermosphere near the F2 peak undergoes strong heating during geomagnetic storms. Experimental studies at middle and equatorial latitudes have indicated that heating occurs during geomagnetic storms, although the overall morphology of these temperature changes is not clear. In this paper we use data from the DE-2 (dynamics explorer) satellite to study this morphology at middle and high latitudes, and then use a simulation of the November 24, 1982 storm, by the NCAR–TIGCM, to compare model output and data on a "one-on-one" basis for an individual orbit in the middle of this storm. Agreement between model and data is good in the winter hemisphere, so we use a thermodynamic diagnostic processor to make a preliminary investigation of the mechanisms by which geomagnetic storms cause temperature increases at lower latitudes. The major conclusions from this work are (i) unlike compositional changes, thermospheric temperature changes do not display a long "tail" into the post-midnight, mid-latitude region; (ii) the pattern of heating during geomagnetic storms is complex, a result of the complicated physical processes that occur during geomagnetic storms; (iii) heating due to advection is approximately balanced by expansion of the gas and downward heat conduction in the postmidnight region; (iv) model predictions for this storm indicate that the greatest temperature increase at 40° N is seen in the dawn sector; (v) early in the storm the strongest compressional heating at latitudes near 40° N is found in the premidnight region, where parcels of air are slowed by sunward ion convection, and consequently converge causing downward winds; (vi) compressional heating also occurs in the afternoon, in a region where expansion of the gas, and hence cooling, occurs during quiet geomagnetic times.

scholarly journals Shoe–Floor Interactions in Human Walking With Slips: Modeling and Experiments

2018 ◽  
Vol 140 (3) ◽  
Author(s):  
Mitja Trkov ◽  
Jingang Yi ◽  
Tao Liu ◽  
Kang Li
Keyword(s):  
Experimental Studies ◽  
Human Walking ◽  
Force Distribution ◽  
Computational Approaches ◽  
Modeling Analysis ◽  
Increased Risk ◽  
Model Predictions ◽  
Modeling And Experiments ◽  
Deformation Measurements ◽  
Tribological Parameters

Shoe–floor interactions play a crucial role in determining the possibility of potential slip and fall during human walking. Biomechanical and tribological parameters influence the friction characteristics between the shoe sole and the floor and the existing work mainly focus on experimental studies. In this paper, we present modeling, analysis, and experiments to understand slip and force distributions between the shoe sole and floor surface during human walking. We present results for both soft and hard sole material. The computational approaches for slip and friction force distributions are presented using a spring-beam networks model. The model predictions match the experimentally observed sole deformations with large soft sole deformation at the beginning and the end stages of the stance, which indicates the increased risk for slip. The experiments confirm that both the previously reported required coefficient of friction (RCOF) and the deformation measurements in this study can be used to predict slip occurrence. Moreover, the deformation and force distribution results reported in this study provide further understanding and knowledge of slip initiation and termination under various biomechanical conditions.

Stick-Slip and Whirl Motions of Drill Strings: Numerical and Experimental Studies

2011 ◽  
Author(s):  
Nicholas Vlajic ◽  
Chien-Min Liao ◽  
Hamad Karki ◽  
Balakumar Balachandran
Keyword(s):  
Experimental Studies ◽  
Drill String ◽  
Distributed Parameter ◽  
Stick Slip ◽  
Distributed Parameter Model ◽  
Experimental Apparatus ◽  
Control Schemes ◽  
Model Predictions ◽  
Drilling Operations ◽  
Good Agreement

The dynamics of drill strings, which are long structures used in drilling operations, are explored numerically and experimentally within this article. A reduced-order distributed parameter model that allows for coupled bending and torsional motions is presented along with forces that take into account interactions between the drill string and the wellbore. Further, a scaled experimental apparatus is presented along with results. Both experimental results and model predictions show backward whirling. Stick-slip interactions are investigated numerically, and the simulation results are seen to be in good agreement with experimental observations. These results could prove useful when designing control schemes for mitigating undesirable torsional and bending motions.

Periodicities of cardiac mechanics

1991 ◽  
Vol 261 (2) ◽  
pp. H424-H433
Author(s):  
S. A. Ben-Haim ◽  
G. Fruchter ◽  
G. Hayam ◽  
Y. Edoute
Keyword(s):  
Experimental Studies ◽  
Stable Limit Cycle ◽  
Cardiac Mechanics ◽  
Left Ventricular ◽  
Stable Limit ◽  
End Diastolic Volume ◽  
Model Predictions ◽  
Parameter Values ◽  
Theoretical Simulations ◽  
Working Heart

Using a finite-difference equation to model cardiac mechanics, we simulated the stable action of the left ventricle. This model describes the left ventricular end-diastolic volume as a function of the previous end-diastolic volume and several physiological parameters describing the mechanical properties and hemodynamic loading conditions of the heart. Our theoretical simulations demonstrated that transitions (bifurcations) can occur between different modes of dynamic organization of the isolated working heart as parameters are changed. Different regions in the parameter space are characterized by different stable limit cycle periodicities. Experimental studies carried out in an isolated working rat heart model verified the model predictions. The experimental studies showed that stable periodicities were invoked by changing the parameter values in the direction suggested by the theoretical analysis. We propose in the present work that mechanical periodicities of the heart action are an inherent part of its nonlinear nature. The model predictions and experimental results are compatible with previous experimental data but may contradict several hypotheses suggested to explain the phenomenon of cardiac periodicities.

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