scholarly journals Vibrational spectroscopic study of intensities and shifts of symmetric vibration modes of ozone diluted by cumene

2016 ◽  
Vol 4 (1) ◽  
pp. 5 ◽  
Author(s):  
A. Heidari ◽  
C. Brown
Keyword(s):  
Spectroscopic Study ◽  
Vibration Mode ◽  
Experimental Results ◽  
Vibration Modes ◽  
Symmetric Vibration ◽  
Linear Dependency ◽  
Raman Intensities ◽  
And Shifts ◽  
Ir And Raman ◽  
Ft Raman

In the current research, ATR–FTIR and FT–Raman spectroscopies was used to investigate the effect of concentration on IR and Raman intensities and shifts of symmetric vibration modes of Ozone diluted by Cumene. The symmetric vibration mode of Ozone was observed at IR and Raman shifts of 850 and 975 cm-1, respectively. By reducing the concentration of Ozone, its intensity also was reduced and the symmetric vibration mode of Cumene was observed at IR and Raman shifts of 1050 and 1185 cm-1, respectively. The concentration has not influence on IR and Raman shifts of vibration modes. The experimental results were confirmed the linear dependency of IR and Raman intensities to the concentration of sample.Ozone molecule (left illustration) and Cumene molecule (right illustration) (Santiago-López et al. 2010; Guevara-Guzmán et al. 2009; Pereyra-Muñoz et al. 2006; Foucaud et al. 2006; Elsayed 2001; van Hoof et al. 1997; Chrostowski et al. 1983; Boehme et al. 1992; Catalá et al. 2013; Balvers et al. 1992; Marker et al. 1986).

Identifying VIV Vibration Modes by Use of the Empirical Orthogonal Functions Technique

2002 ◽  
Author(s):  
Gudmund Kleiven
Keyword(s):  
Model Test ◽  
Vibration Mode ◽  
Multivariate Data ◽  
Empirical Orthogonal Functions ◽  
Mode Shapes ◽  
Data Sets ◽  
Vibration Modes ◽  
Ocean Engineering ◽  
Orthogonal Functions ◽  
Related Technique

The Empirical Orthogonal Functions (EOF) technique has widely being used by oceanographers and meteorologists, while the Singular Value Decomposition (SVD being a related technique is frequently used in the statistics community. Another related technique called Principal Component Analysis (PCA) is observed being used for instance in pattern recognition. The predominant applications of these techniques are data compression of multivariate data sets which also facilitates subsequent statistical analysis of such data sets. Within Ocean Engineering the EOF technique is not yet widely in use, although there are several areas where multivariate data sets occur and where the EOF technique could represent a supplementary analysis technique. Examples are oceanographic data, in particular current data. Furthermore data sets of model- or full-scale data of loads and responses of slender bodies, such as pipelines and risers are relevant examples. One attractive property of the EOF technique is that it does not require any a priori information on the physical system by which the data is generated. In the present paper a description of the EOF technique is given. Thereafter an example on use of the EOF technique is presented. The example is analysis of response data from a model test of a pipeline in a long free span exposed to current. The model test program was carried out in order to identify the occurrence of multi-mode vibrations and vibration mode amplitudes. In the present example the EOF technique demonstrates the capability of identifying predominant vibration modes of inline as well as cross-flow vibrations. Vibration mode shapes together with mode amplitudes and frequencies are also estimated. Although the present example is not sufficient for concluding on the applicability of the EOF technique on a general basis, the results of the present example demonstrate some of the potential of the technique.

FT-Raman spectroscopic study of thoracic aortic wall subjected to uniaxial stress

2009 ◽  
Vol 41 (10) ◽  
pp. 1163-1169 ◽  
Author(s):  
J. Hanuza ◽  
M. Ma̧czka ◽  
M. Ga̧sior-Głogowska ◽  
M. Komorowska ◽  
M. Kobielarz ◽  
...  
Keyword(s):  
Spectroscopic Study ◽  
Aortic Wall ◽  
Uniaxial Stress ◽  
Raman Spectroscopic ◽  
Raman Spectroscopic Study ◽  
Ft Raman

A study of aging in dental composites using IR and Raman spectroscopy

e-Polymers ◽  
2004 ◽  
Vol 4 (1) ◽  
Author(s):  
Fotini Pallikari ◽  
Soultana Iosifidou
Keyword(s):  
Raman Spectroscopy ◽  
Accelerated Aging ◽  
Monomer Conversion ◽  
Aesthetic Appearance ◽  
Ft Raman Spectroscopy ◽  
Ceramic Fillers ◽  
Photo Curing ◽  
Dental Restorative ◽  
Ir And Raman ◽  
Ft Raman

Abstract The application of dental restorative composites has opened wide possibilities in modern dentistry. The dental pastes studied in this work consist of a dimethacrylate-based matrix to which silica or ceramic fillers are added to improve their mechanical properties, colour stability and aesthetic appearance. The pastes were cured through free-radical polymerisation with visible light and were subjected to accelerated aging in the laboratory. The degree of monomer conversion with photo-curing, studied with FTIR and FT-Raman spectroscopy, was 42 ± 2% on average, which further advanced after aging to 56 ± 4%. The samples exhibited fluorescence at various intensities, which declined by the curing and aging procedures by a maximum of c. 20%, depending on the type of fillers present.

Theoretical Computation and Experimental Analysis of Natural Frequencies of Hot Rolling-Mill Housing

2013 ◽  
Vol 278-280 ◽  
pp. 169-173
Author(s):  
Wei Jin Ma ◽  
Yun Bo Wei ◽  
Feng Lan Li ◽  
Jun Yuan Wang ◽  
Xiao Yan Xiong
Keyword(s):  
Mode Shape ◽  
Hot Rolling ◽  
Rolling Mill ◽  
Natural Frequencies ◽  
Vibration Mode ◽  
Theoretical Calculations ◽  
Mode Frequency ◽  
Experimental Results ◽  
Main Mode ◽  
Hot Rolling Mill

Three-dimensional digital model of hot rolling-mill housing was built. The natural frequency and vibration mode shape of the first 10 order modes of hot rolling mill housing were calculated using ANSYS software. The vibration mode shape was studied in detail. The striking vibration signal and subsequently the natural frequencies were measured by placing two 3-Dimensional accelerators in the key points of the rolling mill horsing. Theoretical calculations and experimental results verified each other，high agreement was shown between the experimental results and the theoretical results. The first 10 mode frequency all appeared in the experiment signal with low error. The main mode frequency (117.3Hz) of the experimental signal has the lowest error down to 0.07%.

Weak Radiator Design Using Dimples

2010 ◽  
Author(s):  
Wen Nan Cheng ◽  
Chih Chun Cheng ◽  
Gary H. Koopmann
Keyword(s):  
Vibration Mode ◽  
Design Method ◽  
Vibration Modes ◽  
The Finite Element Method ◽  
Key Issues ◽  
Beam Surface ◽  
Specific Frequency ◽  
Radiated Sound ◽  
Radiated Sound Power ◽  
Do So

A design method for achieving minimum sound radiation from a beam is presented. The strategy is to form a series of cylindrical dimples on the beam surface in order to make one or more vibration modes of this dimpled beam have the same shape as the weak modes. Consequently, the dimpled beam behaves as a weak radiator when one or more vibration modes are excited. Instead of minimizing the radiated sound power at a specific frequency or in a bandwidth, the objective is to maximize the modal assurance coefficient (MAC) which quantifies resemblance between the vibration mode of a dimpled beam and a weak mode. To perform this strategy, two key issues are addressed in this paper. The first is to determine the so-called weak mode of a beam. And the second is how to determine the required dimple size and the dimple location on this beam so that the dimpled beam may have vibration modes resembled to the weak modes. A methodology to do so based on the finite element method and the mode assurance criteria is proposed. Results show that the radiation efficiency of the dimpled beam after optimization using MAC as the objective is generally lower than the uniform beam. However, the effectiveness of this strategy depends on how close in shape between the vibration mode of the dimpled beam and the designated weak mode.

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