AN APPLICATION OF TWO EXPERIMENTAL MODAL ANALYSIS METHODS FOR THE DETERMINATION OF OPERATIONAL DEFLECTION SHAPES

1996 ◽  
Vol 196 (4) ◽  
pp. 429-438 ◽  
Author(s):  
J. Kromulski ◽  
E. Hojan
Mechanik ◽  
2017 ◽  
Vol 90 (10) ◽  
pp. 876-878
Author(s):  
Tomasz Wala ◽  
Krzysztof Lis

As part of a comprehensive study of influence of vibrations on the abrasive waterjet process, this article discusses about the identification of modal properties of the waterjet machine including the cutter head. The experimental modal analysis of the main gantry components of the machine construction was carried out, i.e. the carrier beam with the tool support and the cutter head. Determination of the modal properties of the machine allowed the identification of these vibrations, which are directly attributable to the construction of the machine and indicate them in the signal registered during the cutting.


BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 7687-7713
Author(s):  
Vasile Ghiorghe Gliga ◽  
Mariana Domnica Stanciu ◽  
Silviu Marian Nastac ◽  
Mihaela Campean

This research investigated the potential of some European wood species for use in the manufacturing of the back plates of violins as an alternative to the quite rare curly maple wood. An experimental modal analysis was employed for this purpose using the impact hammer method. The modal analysis was performed both on the top and back plates, as individual structures, and then after being integrated into the violin body. The modal analysis envisaged the determination of the eigenfrequencies (natural frequencies), the number of spectral components, and the quality factor, as important indicators of the acoustic performances of a musical instrument. A multi-criteria analysis based on the values obtained for these indicators allowed interesting findings concerning the acoustic properties of the selected wood species (hornbeam, willow, ash, bird-eye maple, walnut, and poplar). Same as curly maple, they all have special aesthetics, but only hornbeam, willow, and ash wood proved to have acoustic potential as well.


2015 ◽  
Vol 39 (1) ◽  
pp. 145-149 ◽  
Author(s):  
Ewa B. Skrodzka ◽  
Bogumił B.J. Linde ◽  
Antoni Krupa

Abstract Experimental modal analysis of a violin with three different tensions of a bass bar has been performed. The bass bar tension is the only intentionally introduced modification of the instrument. The aim of the study was to find differences and similarities between top plate modal parameters determined by a bass bar perfectly fitting the shape of the top plate, the bass bar with a tension usually applied by luthiers (normal), and the tension higher than the normal value. In the modal analysis four signature modes are taken into account. Bass bar tension does not change the sequence of mode shapes. Changes in modal damping are insignificant. An increase in bass bar tension causes an increase in modal frequencies A0 and B(1+) and does not change the frequencies of modes CBR and B(1-).


Author(s):  
Willem Talakua ◽  
Eygner Gerald Talakua

The purpose of this study is to study the maximization of business profits through the determination of the optimal use of production factors in the trawl ring business in Latuhalat. Observations and direct interviews based on questionnaires were carried out on 3 fishermen who owned trawl ring businesses in 3 hamlets in Latuhalat. Data were analyzed using business profit analysis methods and linear programming analysis. The results showed that: 1). The optimal use of production factors for trawling by the respondents in Latuhalat is 41 - 45 trips in June using 15.2 - 21.1 liters of gasoline, 280.9 - 304.4 liters of gasoline, 10.1 - 21 , 2 liters of oil, using labor as much as 15-17 people for 8 hours / day, and using transportation and FAD services as much as 351.3 - 360 HOK or 8 hours per day; and 2). The maximum profit that can be obtained from trawling rings by respondents in Latuhalat is Rp. 165,545,500 - up to Rp. 184,800,000, - in June. To achieve this maximum profit, respondents need to produce 25,270.3 kg of fish to 27,540.98 kg in June.


Kerntechnik ◽  
2008 ◽  
Vol 73 (3) ◽  
pp. 118-121
Author(s):  
T. Heinrich ◽  
L. Funke ◽  
M. Köhler ◽  
U.-K. Schkade ◽  
F. Ullrich ◽  
...  

2020 ◽  
Vol 16 ◽  
Author(s):  
Aykut Kul ◽  
Murat Ozdemir ◽  
Selma Ozilhan ◽  
Olcay Sagirli

Background: Buprenorphine is quite common in the illicit market. Buprenorphine-containing drugs abuse is frequently encountered in patients. The analysis methods used to determine the abuse of buprenorphine and norbuprenorphine are important for forensic science. Buprenorphine is metabolized to norbuprenorphine by the liver. Objective: Therefore, the determination of buprenorphine and norbuprenorphine in urine is one of the methods to determine the abuse of buprenorphine. Methods: In this study, we have developed a precise, simple, and rapid ultra-performance liquid chromatographytandem mass spectrometer method for the determination of buprenorphine and norbuprenorphine simultaneously. Results: The developed method was validated in terms of selectivity and linearity, which was in the range of 9–1800 ng/mL for both buprenorphine and norbuprenorphine. The intra-assay and inter-assay accuracy and precision were found within acceptable limits of the EMA guideline. Lower limits of quantitation were 9 ng/mL for both buprenorphine and norbuprenorphine. Conclusion: The developed method was successfully applied for the determination of both analytes in the proficiency testing samples.


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