scholarly journals Determination Of Acoustic Properties Of Rice Bran Composites A Material Handler Noise

2018 ◽  
Vol 7 (1) ◽  
pp. 11
Author(s):  
Rafika Andari
Author(s):  
X. Wu ◽  
M. Vahdati ◽  
A. I. Sayma ◽  
M. Imregun

This paper reports the results of an ongoing research effort to explain the underlying mechanisms for aeroacoustic fan blade flutter. Using a 3D integrated aeroelasticity method and a single passage blade model that included a representation of the intake duct, the pressure rise vs. mass flow characteristic of a fan assembly was obtained for the 60%–80% speed range. A novel feature was the use of a downstream variable-area nozzle, an approach that allowed the determination of the stall boundary with good accuracy. The flutter stability was predicted for the 2 nodal diameter assembly mode arising from the first blade flap mode. The flutter margin at 64% speed was predicted to drop sharply and the instability was found to be independent of stall effects. On the other hand, the flutter instability at 74% speed was found to be driven by flow separation. Further post-processing of the results at 64% speed indicated significant unsteady pressure amplitude build-up inside the intake at the flutter condition, thus highlighting the link between the acoustic properties of the intake duct and fan blade flutter.


2020 ◽  
Vol 15 (2) ◽  
pp. 193-198
Author(s):  
Zhiying Shao ◽  
Mei Xue ◽  
Qin Liu ◽  
Peng Li ◽  
Yong Fang ◽  
...  

2017 ◽  
Vol 94 (3) ◽  
pp. 375-385 ◽  
Author(s):  
Maitê S. Cuevas ◽  
Patricia T. de Souza ◽  
Christianne E. da Costa Rodrigues ◽  
Antonio J. A. Meirelles
Keyword(s):  

2019 ◽  
Vol 126 (7) ◽  
pp. 075106 ◽  
Author(s):  
Nicolas Kurz ◽  
Anli Ding ◽  
Daniel F. Urban ◽  
Yuan Lu ◽  
Lutz Kirste ◽  
...  

2020 ◽  
Vol 851 ◽  
pp. 164-171 ◽  
Author(s):  
Aman Santoso ◽  
Abdurrohman ◽  
Anugrah Ricky Wijaya ◽  
Dedek Sukarianingsih ◽  
Sumari ◽  
...  

Vegetable oil is one of rice bran components. As triglycerides, vegetable oil can be converted to fatty acid and alkyl esters for further treatments. Synthesis of alkyl ester oil can be carried out by esterification or transesterification reaction, depending on the quality of the oil and the catalyst. The purposes of this study are 1) Rice bran oil isolation, 2) Oil esterification 3) Characterization and identification of the methyl ester that compose rice bran oil. The stages in this research are 1) Extraction of rice bran oil, 2) Synthesis of methyl ester from rice bran through esterification reaction, 3) Methyl ester characterization of rice bran oil and its potential test as biodiesel included determination of density, viscosity, refractive index, and acid number test, 4) The identification of synthesized methyl esters composition using GC-MS. The results showed that rice bran oil has a yield of 18.09%. Synthesis of methyl esters from rice bran oil through the esterification reaction with a catalyst acid yields 72.37%. The characters of the synthesized methyl ester are on the range of biodiesel quality standards, namely, the density is 0.850 g/mL, viscosity is 4.73 cSt, a refractive index is 1.45871, and an acid number is 0.76 g KOH/g methyl ester, therefore it is claimed that the synthesized methyl esters have the potential as biodiesel. The GC-MS result showed the presence of compounds methyl tetradecanoate (0.38%), methyl hexadecanoate (40.67%), methyl 9-octadecenoate (53.68%), methyl octadecanoate (5.02%), and methyl eicosanoate (0.14%).


2019 ◽  
Vol 271 ◽  
pp. 630-638 ◽  
Author(s):  
Piramon Pokkanta ◽  
Phumon Sookwong ◽  
Manatchanok Tanang ◽  
Saranya Setchaiyan ◽  
Pittayaporn Boontakham ◽  
...  

Author(s):  
Lukáš Fiala ◽  
Robert Černý

The presence of high level of acoustic load especially in urban areas is becoming a serious problem in the present. In order to protect people against adverse effects of audio noise on health and personal well-being in buildings located in such areas, convenient construction materials with sophisticated geometric arrangement should be used. Bearing structures of new houses in the Czech Republic are widely made of different types of brick blocks. Such brick blocks consist of solid matrix and cavities designed in an optimized geometrical way in order to assure better thermal and hygric properties. Previous studies dealing both with acoustic properties in an empirical way and with the theoretical aspects of acoustic attenuation in building materials were not very numerous. Nevertheless, they gain constantly in importance with increasing acoustic load of the buildings surroundings. In this paper, a theoretical approach for the determination of acoustic properties, which is convenient for the description of sound waves propagation in building materials, is introduced.


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