Design of Optimum Acoustic Treatment for Rectangular Ducts With Flow

1976 ◽  
Author(s):  
R. E. Motsinger ◽  
R. E. Kraft ◽  
J. W. Zwick
Keyword(s):  
Acoustic Pressure ◽  
Noise Suppression ◽  
Optimization Technique ◽  
Measured Data ◽  
Acoustic Velocity ◽  
Single Element ◽  
Mean Flow ◽  
Acoustic Treatment ◽  
Treatment Design

A design optimization technique for acoustic treatment in rectangular ducts with uniform mean flow is presented. The technique is based on the acoustic wave solution in terms of series of characteristic duct modes. The analysis allows multiple axial treatment sections along the length of the duct and requires a known modal characterization of the sound source. Conditions of acoustic pressure and acoustic velocity continuity are used to match modal solutions at planes of impedance discontinuity in the duct. Experimental techniques for obtaining this modal characterization are presented. Using duct modes measured at the source plane, the optimization technique is exercised to design an optimized single element liner in a case without mean flow, and optimized single and dual element liners in cases with mean flow. The validity of the program for predicting noise suppression is demonstrated by comparing analytical predictions with measured data for several (non-optimum) cases. Application to treatment design in turbomachinery exhaust ducts is considered.

Microstructure Evolution Characterization of Multi-Pass Hot Rolling Simulation of Nb-Ti Microalloyed Steel

2014 ◽  
Vol 936 ◽  
pp. 1141-1145
Author(s):  
Bin Shen ◽  
Song He Zhu ◽  
Heng Hua Zhang
Keyword(s):  
Hot Rolling ◽  
Static Recrystallization ◽  
Microalloyed Steel ◽  
Measured Data ◽  
Mean Flow ◽  
Austenite Grain Size ◽  
Austenite Grain ◽  
Mean Flow Stress ◽  
The Mean

In this study, a improved mathematical model was developed for Nb-Ti microalloyed steel during hot rolling simulation. Using the compression test, the dynamic and static recrystallization characteristics of Nb-Ti microalloyed steel were studied. Though multi-pass hot rolling simulation, it is found that the recrystallization during hot rolling can play an important role, it can make the mean flow stress lower and refine the grains. And respective comparison between calculated and measured data of microstructure showed some of the validation of the built model. Meanwhile, the evolution characteristic of average austenite grain size during hot rolling can be achieved by theoretical model and experiment.

Digital x-ray mapping of nanometer-size supported bimetallic catalysts

1988 ◽  
Vol 46 ◽  
pp. 530-531
Author(s):  
L. T. Germinario
Keyword(s):  
Background Radiation ◽  
Metal Cluster ◽  
Single Element ◽  
Beam Diameter ◽  
X Rays ◽  
X Ray ◽  
Major Interest ◽  
Induced Changes

Understanding the role of metal cluster composition in determining catalytic selectivity and activity is of major interest in heterogeneous catalysis. The electron microscope is well established as a powerful tool for ultrastructural and compositional characterization of support and catalyst. Because the spatial resolution of x-ray microanalysis is defined by the smallest beam diameter into which the required number of electrons can be focused, the dedicated STEM with FEG is the instrument of choice. The main sources of errors in energy dispersive x-ray analysis (EDS) are: (1) beam-induced changes in specimen composition, (2) specimen drift, (3) instrumental factors which produce background radiation, and (4) basic statistical limitations which result in the detection of a finite number of x-ray photons. Digital beam techniques have been described for supported single-element metal clusters with spatial resolutions of about 10 nm. However, the detection of spurious characteristic x-rays away from catalyst particles produced images requiring several image processing steps.

scholarly journals A Setup for Microscopic Studies of Ultrasounds Effects on Microliters Scale Samples: Analytical, Numerical and Experimental Characterization

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 847
Author(s):  
Florian N. Gailliègue ◽  
Mindaugas Tamošiūnas ◽  
Franck M. André ◽  
Lluis M. Mir
Keyword(s):  
Culture Medium ◽  
Small Volume ◽  
Acoustic Pressure ◽  
Experimental Characterization ◽  
Focal Distance ◽  
Microscopic Studies ◽  
Cell Membrane Permeabilization ◽  
Ultrasonic Parameters ◽  
Rigid Walls

Sonoporation is the process of cell membrane permeabilization, due to exposure to ultrasounds. There is a lack of consensus concerning the mechanisms of sonoporation: Understanding the mechanisms of sonoporation refines the choice of the ultrasonic parameters to be applied on the cells. Cells’ classical exposure systems to ultrasounds have several drawbacks, like the immersion of the cells in large volumes of liquid, the nonhomogeneous acoustic pressure in the large sample, and thus, the necessity for magnetic stirring to somehow homogenize the exposure of the cells. This article reports the development and characterization of a novel system allowing the exposure to ultrasounds of very small volumes and their observation under the microscope. The observation under a microscope imposes the exposure of cells and Giant Unilamellar Vesicles under an oblique incidence, as well as the very unusual presence of rigid walls limiting the sonicated volume. The advantages of this new setup are not only the use of a very small volume of cells culture medium/microbubbles (MB), but the presence of flat walls near the sonicated region that results in a more homogeneous ultrasonic pressure field, and thus, the control of the focal distance and the real exposure time. The setup presented here comprises the ability to survey the geometrical and dynamical aspects of the exposure of cells and MB to ultrasounds, if an ultrafast camera is used. Indeed, the setup thus fulfills all the requirements to apply ultrasounds conveniently, for accurate mechanistic experiments under an inverted fluorescence microscope, and it could have interesting applications in photoacoustic research.

scholarly journals Dual Feed, Single Element Antenna for WiMAX MIMO Application

2008 ◽  
Vol 2008 ◽  
pp. 1-5 ◽  
Author(s):  
Frank M. Caimi ◽  
Mark Mongomery
Keyword(s):  
Correlation Coefficient ◽  
Performance Metrics ◽  
Measured Data ◽  
Antenna Pattern ◽  
Relative Performance ◽  
Equal Length ◽  
Impedance Match ◽  
Single Element ◽  
Pattern Correlation ◽  
Operating Bandwidth

A novel u-shaped single element antenna having two feed ports is compared with two equal length monopoles separated by a distance equivalent to the width. A discussion of relative performance metrics is provided for MIMO applications, and measured data is given for comparison. Good impedance match and isolation of greater than  dB are observed over the operating bandwidth from 2.3 to 2.39 GHz. The antenna patterns are highly uncorrelated, as illustrated by computation of the antenna pattern correlation coefficient for the two comparison monopoles.

Acoustic Velocity Measurements and Interpretation for Challenging Fluid Systems

SPE Journal ◽  
2016 ◽  
Vol 22 (01) ◽  
pp. 103-119 ◽  
Author(s):  
Edward Lewis ◽  
Birol Dindoruk
Keyword(s):  
Heat Capacity ◽  
Isothermal Compressibility ◽  
Measured Data ◽  
Acoustic Velocity ◽  
Hydrocarbon Mixture ◽  
Data Sets ◽  
Velocity Measurements ◽  
Numerical Work ◽  
Reliable Determination ◽  
Quality Control Tool

Summary In terms of experimentation, acoustic velocity can be measured with a high degree of accuracy. Several thermodynamic properties related to acoustic velocity such as density, isothermal compressibility, and heat capacity can be extracted from measured data. In this study, technical improvements are implemented in an effort to develop a technique for fast and reliable determination of fluid properties on the basis of acoustic velocity measurements over an expanded range of pressures. The potential use of this device as a quality-control tool in typical pressure/volume/temperature (PVT) measurements is demonstrated. Baseline measurements matched to published literature verify the suitability of the device. Results of tests on three recombined oil samples containing dissolved gas, with prescribed gas/oil ratios (GORs), and one bitumen sample are presented. A sharp change in the acoustic velocity trend near the gas/liquid-saturation point is evidence of gas evolution during depressurization. Strong attenuation complicates measurement of acoustic velocity on the heavy fluids used in this study. Blending bitumen with a midrange-molecular-weight hydrocarbon mixture enables estimation of the undiluted-fluid acoustic velocity by extrapolation. By use of the measured acoustic velocity data available, a methodology is developed to estimate and quality check measured isothermal compressibility (κT) values. This is especially important for low-compressibility systems. Heat-capacity data for simple alkanes (CH4 to n-C10) and toluene helps to define a reasonable range of heat-capacity ratio (γ) expected for typical reservoir fluids. For the typical values of acoustic velocity encountered in the pressure and temperature range of interest, the isothermal compressibility can be calculated and/or quality checked by use of estimated values of γ. In addition, by use of various data sets and by performing graphical error analysis, we have shown the reasons that the methodology works. Available data for n-decane and n-hexadecane along with measured data for a live oil and numerical work on calibrated data sets in this study are used to develop the methodology.

scholarly journals ASPECTOS BIOMÉTRICOS E MORFOLÓGICOS DE FRUTOS E SEMENTES DE Schinopsis brasiliensis

Nativa ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 219
Author(s):  
Jania Claudia Camilo dos Santos ◽  
Dayane Mércia Ribeiro Silva ◽  
Renato Nunes Costa ◽  
Carlos Humberto Da Silva ◽  
Wilton Da Silva Santos ◽  
...  
Keyword(s):  
Measured Data ◽  
Descriptive Statistics ◽  
Morphological Description ◽  
Environmental Restoration ◽  
Biometric Data ◽  
Water Imbibition ◽  
Morphological Aspects ◽  
Length Width ◽  
Forest Seeds

O objetivo deste trabalho foi avaliar a biometria e morfologia de S. brasiliensis, visando identificar características que auxiliem no uso e propagação dessa espécie da Caatinga em programa de restauração ambiental. Os dados biométricos foram obtidos a partir de 1000 frutos e 1000 sementes. Foram medidos o comprimento, largura, espessura e massa de frutos e sementes. Os dados foram ajustados utilizando a estatística descritiva e teste de Shapiro-Wilk. Para a descrição morfológica dos frutos, foram relatadas observações sobre os aspectos externos e internos do pericarpo, consistência da casca, coloração, brilho, forma e deiscência. Já as descrições morfológicas externa das sementes foram feitas observações sobre consistência, coloração, textura, forma e hilo. A caracterização biométrica de frutos e sementes de S. brasiliensis, possibilitou verificar a variação existente entre as classes biométricas através de histograma de frequência. Os frutos apresentam morfologia completa, em forma de sâmara, indeiscente e monospérmico. As sementes foram caracterizadas em oblongas e reniformes, envolvidas pelo endocarpo, resultando no pirênio, sendo esta a camada que dificulta o processo de embebição de água, a qual antecede a germinação, no entanto, esta camada é capaz de promover maior longevidade as sementes.Palavras-chave: análises biométricas, características morfológicas, sementes florestais, Caatinga. BIOMETRIC AND MORPHOLOGICAL ASPECTS OF THE FRUITS AND SEEDS OF SCHINOPSIS BRASILIENSIS ABSTRACT:The objective of this work was to evaluate the biometry and morphology of S. brasiliensis, aiming to identify traits that help in the use and propagation of this Caatinga species in an environmental restoration program. Biometric data were obtained from 1000 fruits and 1000 seeds. The length, width, thickness and mass of fruits and seeds were measured. Data were adjusted using descriptive statistics and Shapiro-Wilk test. For the fruits morphological description, observations on the external and internal traits of the pericarp, peel consistency, coloration, brightness, shape and dehiscence were reported. Already the external morphological descriptions of the seeds were made on consistency, color, texture, shape and thread. The biometric characterization of fruits and seeds of S. brasiliensis made it possible to verify the variation between the biometric classes through frequency histogram. The fruits presented complete morphology, in the form of a samara, indiscriminate and monospermic. The seeds were characterized in oblong and reniform, surrounded by the endocarp, resulting in the pyrenium, which is the layer that hinders the process of water imbibition, which precedes the germination, however this layer is able to promote greater longevity of the seeds.Keywords: biometric analyzes, morphological traits, forest seeds, Caatinga. DOI:

scholarly journals Sound, Noise and Speech at the 9000-Seat Holy Trinity Church in Fatima, Portugal

2010 ◽  
Vol 35 (2) ◽  
pp. 145-156 ◽  
Author(s):  
António Carvalho ◽  
Pedro Silva
Keyword(s):  
Sound Pressure ◽  
Measured Data ◽  
Reverberation Time ◽  
Index Method ◽  
Sound System ◽  
Holy Trinity ◽  
Acoustic Quality ◽  
Design Values

Abstract This paper presents the interior acoustical characterization of the 9,000-seat church of the Holy Trinity in the Sanctuary of Fátima, Portugal, inaugurated in 2007. In situ measurements were held regarding interior sound pressure levels (with and without the HVAC equipment working), NC curves, RASTI (with and without the installed sound system) and reverberation time. The results are presented and commented according to the design values. A comparison is made with other churches in the world, also with a very large volume (for instance the Basilica Mariacka in Gdańsk). The measured data are also used to calculate a global index of this church acoustic quality using Engel's and Kosała's Index Method.

APPLICATION OF OPTIMIZATION TECHNIQUE IN SYNTHESIS AND CHARACTERIZATION OF SODIUM CARBOXY ETHYL GUAR.

2012 ◽  
Vol 4 ◽  
pp. 162-171
Author(s):  
Hasanpasha .N Sholapur . ◽  
Fatima Sanjeri Dasankoppa . ◽  
N.G.Nangundaswamy . ◽  
Arunkumar G R .
Keyword(s):  
Optimization Technique ◽  
Synthesis And Characterization

Detailed experimental and numerical characterization of turbulent flow in components of a water treatment plant

2019 ◽  
Vol 80 (11) ◽  
pp. 2117-2130
Author(s):  
Ivan Matías Ragessi ◽  
Carlos Marcelo García ◽  
Santiago Márquez Damián ◽  
Cecilia Pozzi Piacenza ◽  
Mariano Ignacio Cantero
Keyword(s):  
Water Treatment ◽  
Turbulent Flow ◽  
Treatment Plant ◽  
Acoustic Doppler Current Profiler ◽  
Water Treatment Plant ◽  
Mean Flow ◽  
Cross Sectional ◽  
Flow Recirculation ◽  
Hydraulic Design

Abstract This paper presents a detailed characterization of turbulence in the incoming flow to the clarification component of a water treatment plant, ‘Los Molinos’ (Córdoba, Argentina). The main problems were related to the presence of turbulent flow patterns throughout the treatment, affecting the proper development of the physical processes required for water clarification. Namely: (a) a poor hydraulic design that could produce a non-homogeneous spatial distribution of the flow, recirculation zones and flow stagnation, and a non-uniform discharge distribution among the sedimentation units as a result of different cross-sectional dimensions of the transverse-channel, and (b) high turbulence intensity that affect the flocs' size as well as the efficiency of the settling tanks and filters. Firstly, a detailed in-situ experimental characterization of the turbulent flow was undertaken. An acoustic Doppler velocimeter (ADV) was used to characterize the flow turbulence, whereas for discharge measurements and mean flow velocity field an acoustic Doppler current profiler (ADCP) was employed. Secondly, a numerical model, based on the Reynolds-averaged Navier–Stokes (RANS) equations and the - turbulence closure model, was validated with the experimental data. Finally, based on the results, a diagnosis and recommendations were made for the optimization of the hydraulic design of the water treatment plant.

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