Comparison of Dynamic Behavior of C18 HPLC Columns by Stimulus-Response Analysis. I. Determination of Peclet Numbers

1995 ◽  
Vol 18 (9) ◽  
pp. 1747-1755 ◽  
Author(s):  
Mehmet Mutlu ◽  
Vural Gökmen ◽  
Jale Acar
Keyword(s):  
Dynamic Behavior ◽  
Response Analysis ◽  
Stimulus Response

scholarly journals Thermal Dynamic Behavior in Bi-Zone Habitable Cell with and without Phase Change Materials

Proceedings ◽  
2020 ◽  
Vol 63 (1) ◽  
pp. 41
Author(s):  
Hanae El Fakiri ◽  
Lahoucine Ouhsaine ◽  
Abdelmajid El Bouardi
Keyword(s):  
Thermal Behavior ◽  
Thermal Comfort ◽  
Phase Change ◽  
Dynamic Behavior ◽  
Phase Change Materials ◽  
Energy Performance ◽  
High Energy ◽  
Water Heater ◽  
Simplified Modeling

The thermal dynamic behavior of buildings represents an important aspect of the energy efficiency and thermal comfort of the indoor environment. For this, phase change material (PCM) wallboards integrated into building envelopes play an important role in stabilizing the temperature of the human comfort condition. This article provides an assessment of the thermal behavior of a “bi-zone” building cell, which was built based on high-energy performance (HEP) standards and heated by a solar water heater system through a hydronic circuit. The current study is based on studying the dynamic thermal behavior, with and without implantation of PCMs on envelope structure, using a simplified modeling approach. The evolution of the average air temperature was first evaluated as a major indicator of thermal comfort. Then, an evaluation of the thermal behavior’s dynamic profile was carried out in this study, which allowed for the determination of the PCM rate anticipation in the thermal comfort of the building cell.

Studies on Determination of Natural Frequencies of Industrial Turbine Blades

1995 ◽  
Author(s):  
Mahesh M. Bhat ◽  
V. Ramamurti ◽  
C. Sujatha
Keyword(s):  
Steam Turbine ◽  
Dynamic Behavior ◽  
Turbine Blade ◽  
Natural Frequencies ◽  
Complex Structure ◽  
Turbine Blades ◽  
Blade Root ◽  
Steam Turbine Blade ◽  
Manufacturing Tolerances

Abstract Steam turbine blade is a very complex structure. It has geometric complexities like variation of twist, taper, width and thickness along its length. Most of the time these variations are not uniform. Apart from these geometric complexities, the blades are coupled by means of lacing wire, lacing rod or shroud. Blades are attached to a flexible disc which contributes to the dynamic behavior of the blade. Root fixity also plays an important role in this behavior. There is a considerable variation in the frequencies of blades of newly assembled turbine and frequencies after some hours of running. Again because of manufacturing tolerances there can be some variation in the blade to blade frequencies. Determination of natural frequencies of the blade is therefore a very critical job. Problems associated with typical industrial turbine bladed discs of a 235 MW steam turbine are highlighted in this paper.

Determination of the Effect of Sloshing on the Railcar-Track Dynamic Behavior

2021 ◽  
pp. 131-140
Author(s):  
Juan Carlos Jauregui-Correa ◽  
Frank Otremba ◽  
Jose A. Romero-Navarrete ◽  
Gerardo Hurtado-Hurtado
Keyword(s):  
Dynamic Behavior

scholarly journals Frequency Response Quality Index for Assessing the Mechanical Condition of Transformer Windings

Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 29 ◽  
Author(s):  
Eugeniusz Kornatowski ◽  
Szymon Banaszak
Keyword(s):  
Frequency Response ◽  
Quality Index ◽  
Response Analysis ◽  
Test Results ◽  
Response Curves ◽  
Response Measurement ◽  
Response Quality ◽  
Mechanical Condition ◽  
Measurement Results

Frequency response analysis (FRA) is a popular method for assessing a transformer’s mechanical condition. The paper proposes a new method for interpreting the frequency response measurement results. The currently used numerical indices only give one value, which may be misleading in the analysis, while the proposed frequency response quality index (FRQI) tool analyses three separate features in the whole frequency range. The applied numerical calculations technique allows for estimations of not only the values of the average quality indices, but also locally for given frequency ranges of the analysed spectrum. It allows for determination of the problems that can be found in the active part of a transformer. The presented results come from three transformers, representing cases of typical faults. Two of them are from industry, while one was used for deformational tests in laboratory conditions. The proposed FRQI method showed its usefulness in FRA test results analysis and may be introduced into the automated assessment of such data. Each of the component parameters is sensitive to other types of differences observed between the compared frequency response curves, and may be used as a good quality detection tool.

scholarly journals Improving the Dynamic Behavior of Adjacent Buildings with Fluid Viscous Dampers

2016 ◽  
Vol 10 (12) ◽  
pp. 245
Author(s):  
Solmaz Yaghobzadeh
Keyword(s):  
Control Systems ◽  
Dynamic Behavior ◽  
Time History ◽  
Tall Buildings ◽  
System Response ◽  
Response Analysis ◽  
Viscous Dampers ◽  
Fluid Viscous Dampers ◽  
Adjacent Buildings ◽  
The Impact

Explained ways to strengthen structures against lateral dynamic loads can be divided into two broad categories. The first part is the structural systems for controlling seismic displacement and second part is the use of applying systems of control forces. Response mechanism of structures using control systems are improved and greatly reduce the risks of damage caused by earthquakes.Today the use of these control systems in buildings have been increased and it’s important to reduce vibration of structures is felt more than ever. As well as to improve the dynamic behavior of nearby buildings, control systems can be installed between adjacent buildings as activated, semi-active and inactivated systems. The main purpose of this study is the use of control systems in two similar adjacent buildings to reduce the entire system response which will be the analytical study of the impact of viscous dampers to control system performance.In order to analysis of modeling to improve the dynamic behavior of different adjacent buildings connected with dampers, two models of the original sample will be examined in this article. All examples are different from each other and to elicit response analysis and time history software SAP 2000was used. According to the results the effect of fluid viscous dampers for tall buildings compared shorter building, is less. Also, these dampers for adjacent buildings with different heights than buildings with same height are more effective.

Dynamic behavior and strategy for the complete 1H and 13C assignments for meso-aryl expanded heptaphyrins

2002 ◽  
Vol 06 (06) ◽  
pp. 410-422 ◽  
Author(s):  
Bhawani S. Joshi ◽  
Venkataramanarao G. Anand ◽  
Simi K. Pushpan ◽  
Alagar Srinivasan ◽  
Tavarekere K. Chandrashekar ◽  
...  
Keyword(s):  
Dynamic Behavior ◽  
Intramolecular Hydrogen Bonding ◽  
Native State ◽  
Temperature Dependent ◽  
System A ◽  
Expanded Porphyrins ◽  
Nmr Techniques ◽  
Intramolecular Hydrogen ◽  
C Nmr

The detailed 1 H and 13 C NMR analysis of 5,10,19,24-tetramesityl-33,35,36,38,39-pentathiaheptaphyrin (1) and 5,10,19,24-tetraphenyl-35,36-dioxa-33,38,39-trithiaheptaphyrin (2) in the native and protonated state were carried out using two-dimensional NMR techniques. The analysis suggests that the earlier reported structure containing inverted terminal thiophene of trithiophene should be corrected as the inverted thiophene and furan of bithiophene and bifuran instead of trithiophene system of 1 and 2, respectively. Temperature dependent and titration studies suggest that 1 is less flexible in the native state then 2 due to presence of the mesityl group despite having disorder due to the presence of the heavier sulphur atom. This was consequently proven by the NMR information obtained in 5,10,19,24-tetramesityl-35,36-dioxa-33,38,39-trithiaheptaphyrin (3). Whereas in its protonated state, 2 was found to be less flexible than 1 due to presence of intramolecular hydrogen bonding involving N - H --- O between the pyrrole NH and oxygen of the furan of bifuran system. A systematic NMR strategy has been generated in order to provide complete a structure determination of expanded porphyrins along with their dynamic behavior.

scholarly journals OPTIMUM TUNING PARAMETERS OF TUNED MASS DAMPERS FOR VIBRATION CONTROL OF IRREGULAR HIGHRISE BUILDING STRUCTURES

2014 ◽  
Vol 20 (5) ◽  
pp. 609-620 ◽  
Author(s):  
Mariantonieta Gutierrez Soto ◽  
Hojjat Adeli
Keyword(s):  
Vibration Control ◽  
Dynamic Behavior ◽  
Tall Buildings ◽  
Seismic Loading ◽  
Building Structures ◽  
Tuned Mass Dampers ◽  
Tuning Parameters ◽  
Effective Implementation ◽  
Story Building

Tall buildings have become increasingly one-of-a-kind signature structures that are often irregular in plan and elevation with complicated dynamic behavior. Vibration control of irregular highrise building structures using a recently developed tuned mass dampers (TMD), the bidirectional TMD (BTMD), is investigated. A key issue for effective implementation of a TMD is the determination of their tuning parameters. Eight different sets of equations for tuning the parameters of TMDs are investigated using a 5-story building with plan and elevation irregularity, and a 15-story and a 20-story building with plan irregularity subjected to seismic loading. Appropriate equations are recommended for building structures with a fundamental period of vibrations of greater than one second.

Application of Pseudo-Random Test Signals and Cross Correlation to the Identification of Bulk Handling Plant Dynamic Characteristics

1973 ◽  
Vol 95 (1) ◽  
pp. 31-36 ◽  
Author(s):  
A. W. Roberts ◽  
W. H. Charlton
Keyword(s):  
Dynamic Characteristics ◽  
Cross Correlation ◽  
Natural Frequencies ◽  
Statistical Technique ◽  
Response Analysis ◽  
Frequency Response Analysis ◽  
Grain Handling ◽  
Extraneous Noise ◽  
Cross Correlation Analysis

In the determination of the dynamic characteristics of bulk handling systems the complexity of the problem usually makes experimental identification necessary. Experimental techniques which are based on statistical methods are known to be more reliable than conventional methods such as frequency response analysis. A statistical technique that employs a pseudo-random binary coded signal (prbs) to perturbate the system followed by cross correlation analysis may be used very effectively to identify the dynamic characteristics of the system even in the presence of extraneous noise signals. This paper describes this technique and discusses its application to two areas in the bulk handling field; the first deals with the determination of the natural frequencies of screw conveyors used for grain handling and the second deals with the identification of the dynamic characteristics of grain discharge chutes.

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