Active Control of Structure-Borne Road Noise Using Vibration Actuators

1998 ◽  
Vol 120 (2) ◽  
pp. 517-523 ◽  
Author(s):  
W. Dehandschutter ◽  
P. Sas
Keyword(s):  
Noise Reduction ◽  
Laboratory Experiments ◽  
Frequency Range ◽  
Road Noise ◽  
Control Approach ◽  
Noise Radiation ◽  
Acoustic Control ◽  
Numerical Tools ◽  
Control Set ◽  
Set Up

Structure-borne road noise is generated by road induced excitation forces. The control approach presented here relies on the use of vibration actuators to modify the vibration behavior of the car body such that its noise radiation efficiency is decreased (Active Structural Acoustic Control—ASAC). The controller is optimized using laboratory experiments and numerical tools to simulate the performance a complete vehicle control set-up. Road tests yield a 6.9 dB noise reduction in the frequency range 75–105 Hz at the error microphone and 6.1 dB noise reduction at the passenger’s ear.

Investigation of nitrite pathways in sugar beet extraction

2014 ◽  
pp. 626-635 ◽  
Author(s):  
Florian Emerstorfer ◽  
Christer Bergwall ◽  
Walter Hein ◽  
Mats Bengtsson ◽  
John P. Jensen
Keyword(s):  
Sugar Beet ◽  
Laboratory Experiments ◽  
Ph Value ◽  
Full Scale ◽  
Chemical Effect ◽  
Spectrophotometric Detection ◽  
Sugar Factory ◽  
Chemical Effects ◽  
Set Up ◽  
Nitrate And Nitrite

The investigations presented in this work were carried out in order to further deepen the knowledge about nitrite pathways in the area of sugar beet extraction. The article consists of two parts with different experimental set-up: the first part focuses on laboratory trials in which the fate of nitrate and nitrite was studied in a so-called mini-fermenter. These trials were carried out using juice from the hot part of the cossette mixer of an Agrana sugar factory in Austria. In the experiments, two common sugar factory disinfectants were used in order to study microbial as well as microbial-chemical effects on nitrite formation and degradation caused by bacteria present in the juice. The trials demonstrated that the direct microbial effect (denitrification) on nitrite degradation is more pronounced than the indirect microbial-chemical effect coming from pH value decrease by these bacteria and subsequent nitrite loss. The second part describes the findings from laboratory experiments and full scale factory trials using a mobile laboratory set-up based on insulated stainless steel containers and spectrophotometric detection of nitrite in various factory juices. The trials were made at two Nordzucker factories located in Finland (factory A) and Sweden (factory B). The inhibiting effect of the two common sugar factory disinfectants on nitrite formation was evaluated in laboratory trials, whereas the full scale trials focused on one disinfectant. Other trials to evaluate potential contamination sources of thermophilic nitrite producing bacteria to the extraction system, reactivation of nitrite producing bacteria in raw juice and the effect of a pH gradient on bacterial nitrite activity in cossette mixer juice are also reported.

Design of Control System for Hydraulically Vibrated Processing Tomato Fruit Seedling Separation Device

2014 ◽  
Vol 651-653 ◽  
pp. 693-696
Author(s):  
Li Hong Wang ◽  
Rong Qing Liang ◽  
Cheng Song Li ◽  
Za Kan ◽  
Jin Wei Qin
Keyword(s):  
Tomato Fruit ◽  
Simulation Software ◽  
Signal Frequency ◽  
System Control ◽  
Frequency Range ◽  
Hydraulic Simulation ◽  
Separation Device ◽  
Processing Tomato ◽  
Input Signal Frequency ◽  
Set Up

Eccentric style processing tomato fruit seeding separation device exist high machining and assembly precision or other issues. In order to solve this problem, the mode of vibration of hydraulic replaced the eccentric style to drive the fruit seedling separation roller to separate processing tomato effectively. To facilitate adjustment of the hydraulic system, a kind of control circuit PLC as the core was designed according to the actual production requirements. PLC and other elements were selected. The system control signal frequency was initially set up as 1~5 HZ, within the frequency range hydraulic simulation software was used to simulate and analyze the hydraulic vibration system. The result shows that the system rams steady when the input signal frequency range was 1~5HZ.

scholarly journals Acoustic Emission in Snow at Constant Rates of Deformation

1973 ◽  
Vol 12 (64) ◽  
pp. 144-146 ◽  
Author(s):  
W. F. St. Lawrence ◽  
T. E. Lang ◽  
R.L. Brown ◽  
C. C. Bradley
Keyword(s):  
Acoustic Emission ◽  
Brittle Fracture ◽  
Uniaxial Compression ◽  
Laboratory Experiments ◽  
Acoustic Emissions ◽  
Snow Sample ◽  
Frequency Range ◽  
Snow Samples

AbstractAcoustic emissions in the audio spectrum are reported from observations of laboratory experiments conducted on snow samples in uniaxial compression. A number of tests show the pattern of acoustic emissions to be a function of the rate of deformation. Over the frequency range 20 to 7 000 Hz acoustic emissions are associated with rates of deformation corresponding to brittle fracture of the snow sample. Though probably present, no acoustic emissions were detected from samples deforming plastically.

FFT Analysis Using LabView as a Part of Vibration and Preventive Maintenance Class for Senior Level MET students

2005 ◽  
Author(s):  
Aniruddha Mitra ◽  
Sahana Sen
Keyword(s):  
Preventive Maintenance ◽  
Laboratory Experiments ◽  
Vibration Signal ◽  
Engineering Technology ◽  
Technology Program ◽  
Student Activities ◽  
Labview Software ◽  
Vibration Data ◽  
Set Up ◽  
Fft Analysis

An existing senior level elective course on vibration in Mechanical Engineering Technology program at Georgia Southern University has been modified significantly. Two major components have been added to this course. Those are theoretical topics on preventive maintenance and laboratory experiments. As a part of laboratory experiments, Fast Fourier Transform (FFT) was introduced as a possible tool for vibration analysis for the purposes of machine diagnosis. Utilizing the current laboratory set up for the data acquisition systems, LabView software has been used for FFT analysis of signals from various sources. Four different modules were developed and implemented. The modules are as follows: random variation in acceleration of a toy cart due to roughness of the track and pulley, regular uniform wave signal which is generated by the lateral vibration of a cantilever beam at its natural frequency, signal generated by the imported raw data from other sources (e.g. MATLAB) and vibration signal of a shaft mounted on ball bearings in order to detect the defects in the bearing. Each of these modules is illustrated in this paper with suitable examples and suggested student activities and involvements. The results from FFT analysis have been cross checked using other methods and observations. As a follow up, students have been taken to a local industry where significant amount of emphasis is given to preventive maintenance of machineries by vibration data analysis using FFT. Future possible projects include the analysis of vibration data gathered from actual machine shop. This project opens the scope for greater collaborative effort between local industries and classroom activities.

Note on Preliminary Field Trials of a Bacterium to Control the Codling Moth

1953 ◽  
Vol 85 (1) ◽  
pp. 8-8 ◽  
Author(s):  
C. M. Phillips ◽  
Gordon E. Bucher ◽  
June M. Stephens
Keyword(s):  
Bacillus Cereus ◽  
Laboratory Experiments ◽  
Codling Moth ◽  
Field Trials ◽  
Set Up

A bacterium, Bacillus cereus F. and F., which was isolated from diseased larvae of the codling moth, Carpocapsa pomonella (L.), is pathogenic to the codling moth in laboratory experiments (Stephens, 1952).A series of trials was set up at Kentville to test the effectiveness of this bacterium against codling moth larvae in the field. B. cereus spores were propagated according to the method of Reed and McKercher (1948) and shipped to the field as spore suspensions.

scholarly journals Ciprofloxacin loaded castor oil based emulsion: Its antimicrobial, hematotoxicity and soft tissue pathophysiological study in Wister rats

2020 ◽  
Vol 45 (5) ◽  
Author(s):  
A. Bamisaye ◽  
C. O. Eromosele ◽  
E. O. Dare ◽  
O. A. Akinloye
Keyword(s):  
Oral Delivery ◽  
Castor Oil ◽  
Wistar Rats ◽  
Blood Chemistry ◽  
Diffusion Method ◽  
Hematological Indices ◽  
Control Set ◽  
Set Up ◽  
And Control ◽  
Histological Architecture

The emergence of nanocarrier for drug delivery has been flanked with great achievements in the field of nanomedicine. It is however unsafe to assume their toxicological safety. This necessitated examining the toxico-dynamics of ciprofloxacin loaded castor oil based emulsion (COAB+Cp). The emulsions were prepared by mechano-chemical process. The effects of 10 mL per kg of body-weight (BW) of COAB+Cp was estimated in Adult Wistar rats (n=10) for 21 days vis-à-vis a control set up, treated with equal volume of distilled water. The biochemical and haematological parameters were conducted with histopathology of the heart, kidney, spleen and liver. Also, the antimicrobial study on Bacillus. Subtilis (BS) was carried out using the agar well diffusion method. No observable abnormal change in BW gain of both test and control animals. Treatment of animals with COAB+Cp did not cause any observable significant change at P > 0.05 in the blood-chemistry parameters and hematological indices. The photopathological examinations indicates that the histological architecture of vital organs (heart, liver, kidney and spleen) was not compromised in COAB+Cp treated animals. While the recorded value of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of COAB+Cp corroborated its mean zone of inhibition (ZI) values, signifying a better bioactivity of COAB+Cp compared to Cp on BS. COAB+Cp has no cardiotoxic, hematotoxic and hepatotoxic effects on Wistar rats, with increased potency of the encapsulated Cp thus appears promising as a safe vehicle for oral delivery of ciprofloxacin.

scholarly journals Competitive interactions between species of freshwater snails: I. Laboratory: Ia. General methodology

1983 ◽  
Vol 78 (3) ◽  
pp. 335-341 ◽  
Author(s):  
Frederico Simões Barbosa ◽  
Dirceu P. Pereira da Costa ◽  
Francisco Arruda
Keyword(s):  
Laboratory Experiments ◽  
Freshwater Snail ◽  
Current Paper ◽  
Competitive Interactions ◽  
Laboratory Work ◽  
Freshwater Snails ◽  
Technical Advance ◽  
General Methodology ◽  
Different Types ◽  
Set Up

For the development of laboratory experiments on the competitive interacitons between freshwater snail populations, special snail rooms were set up in the main building of the Research Center "Aggeu Magalhães". In the current paper, the first of a series on this subject, the general methodology of the laboratory work is described in detail. Using indoor cement channels in which a uniform seminatural environment was created, interactions of freshwater snail populations can be studied with minimal interference of the usual variables. Controlled indoor environmental techniques, as described in the current paper, may also be utilized in different types of experiments in malacology, and represent a substantial technical advance in malacological work.

Noise Evaluation of Concrete Pavement

2013 ◽  
Vol 368-370 ◽  
pp. 1985-1989
Author(s):  
Ya Min Liu ◽  
Rao Rao Han ◽  
Zhi Jin Tao ◽  
Jie Chen
Keyword(s):  
Noise Reduction ◽  
Noise Level ◽  
Noise Spectrum ◽  
Concrete Pavement ◽  
Noise Characteristic ◽  
Groove Width ◽  
Concrete Pavements ◽  
Frequency Range ◽  
Porous Concrete ◽  
Noise Evaluation

In order to evaluate noise characteristic of concrete pavements with different texture, specimens were prepared carefully by varying groove parameters, such as groove width and space between grooves. Employing tire impact method, the noise level and noise spectrum of different pavements were analyzed. The results indicate that the noise level of transverse grooved concrete pavement is the greatest, and the followings are glossy concrete pavement and longitudinal grooved concrete pavement, porous concrete pavement has the lowest noise level. For grooved pavement, the noise level is promoted with increasing the space between grooves. Besides that, the noise level of transverse grooved concrete pavement becomes greater as the groove width increases. For longitudinal grooved pavement, there is a contrary tendency. It is porous concrete pavement for a frequency larger than 1600HZ. In the whole frequency range, the noise-reduction ability of transverse grooved concrete pavement is the worst.

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