1 Lesson 03: Sound Wave Propagation and Reflection This lesson contains 18 slides plus 14 multiple-choice questions. This lesson was derived from pages 8 through 14 in the textbook:
2 Sound Wave Propagation and Reflection
4 PULSE-ECHO pulse-echo: refers to an ultrasound system that is used for ultrasound imaging by periodically transmitting and receiving short duration sound pulses A pulse-echo system is used for ultrasound imaging. A transducer that is in contact with the patient is periodically supplied with electrical pulses. The transducer converts the electrical pulses into short bursts of mechanical sound energy that are transmitted into the patient.
5 PULSE-ECHO acoustic interface: the reflecting boundary that is formed between two materials with different acoustic impedance characteristics The transmitted sound encounters numerous reflectors, which are also called acoustic interfaces. The interfaces are reflecting boundaries formed by changes in tissue characteristics, such as from soft tissue to blood or fat to muscle. These changes produce echoes that return to the transducer. By keeping track of the transit time, which is the time between transmitted pulses and returning echoes, the ultrasound system learns the locations of the various interfaces. Once the locations are known, the echoes are positioned on a display to form image patterns that reproduce the patient s internal structures.
6 RANGE EQUATION: (in tissue) Pulse-echo ultrasound systems use the range equation to determine the locations of the various interfaces. In soft tissue, sound travels 6.5 microseconds per centimeter. The distance to an interface (in millimeters) equals 0.77 multiplied by the round trip time of the sound pulse (in microseconds). TIME TO THE REFLECTOR (ONE WAY) DISTANCE TO THE REFLECTOR (ONE WAY) ROUND TRIP TIME ROUND TRIP DISTANCE 6.5 µs 10 mm (1 cm) 13 µs 20 mm (2 cm) 5 µs 7.7 mm (0.77 cm) 10 µs cm (1.54 mm) The range equation assumes a velocity (speed of sound) of 1540 meters per second. Variations in the speed of sound have an effect on the distance accuracy of a pulse-echo system, resulting in axial errors.
7 PULSE-ECHO EQUATIONS Pulse Repetition Period = 1 Pulse Repetition Frequency For pulse-echo imaging, the rate at which pulses are transmitted is the pulse repetition rate or pulse repetition frequency (PRF). The PRF is typically greater than 1000 Hz (1kHz) and is often a function of the ultrasound system s DEPTH control. The result of a high PRF is a short pulse repetition period (PRP), which is the interval between the start of successive pulses. When the PRP is too short, a new pulse may be transmitted before the return of deep echoes from the previously transmitted pulse. Deep echoes will be incorrectly displayed. The result is range ambiguity, or depth ambiguity. This decreases the maximum depth that can be accurately imaged. PRF PRP 1000 Hz 1/1000 sec (0.001 sec) 2000 Hz 1/2000 sec ( sec) 4000 Hz 1/4000 sec ( sec)
8 PULSE-ECHO EQUATIONS Duty Factor = Pulse Duration Pulse Repetition Period PRF PRP PULSE DURATION DUTY FACTOR Increase Decrease Increase Decrease Increase Decrease Increase Increase Decrease Decrease The duty factor in a pulse-echo system is normally less than 1% (0.01). Continuous wave Doppler has a duty factor of 100% (1).
9 ACOUSTIC IMPEDANCE: Acoustic Impedance = Density x Velocity The change in a tissue characteristic that creates an acoustic interface is acoustic impedance, which is specific for each type of tissue. The acoustic impedance of a material may be determined mathematically by multiplying the material s density by the velocity of sound in the material. Example: water has a density of 1000 and a sound velocity of 1430, which produces an acoustic impedance of 1,430,000. Acoustic impedance is expressed in rayls. DENSITY VELOCITY ACOUSTIC IMPEDANCE Increase Increase Decrease Decrease Increase Increase Decrease Decrease
10 ACOUSTIC IMPEDANCE (Rayls) Air 400 Fat 1,380,000 Water 1,430,000 Soft Tissue 1,630,000 Muscle 1,700,000 Bone 7,800,000
11 INTERFACE MATERIALS & ECHO STRENGTH Soft Tissue to Muscle - Weak (1%) Fat to Soft Tissue Weak (1%) Soft Tissue to Bone - Medium (50%) Blood to Plaque Medium (50%) Soft Tissue to Air - Very Strong (100%) The greater the disproportion between the acoustic impedance values of the two materials forming an interface, the greater the strength of the returning echo. Weak interfaces have echo reflection coefficients in the 0.01 (1%) range. Medium strength interfaces have echo reflection coefficients in the 0.5 (50%) range. Very strong interfaces have echo reflection coefficients in the 1.0 (100%) range. The transmission coefficient is equal to 1 minus the reflection coefficient.
12 SAGITTAL - LIVER, RIGHT KIDNEY ACOUSTIC SHADOW: THE RESULT OF A STRONG REFLECTION FROM A GALLSTONE contrast agents: tiny, highly reflective, encapsulated gas filled microbubbles or solid particles, which are injected into the blood stream and return echoes that are thousands of times more reflective than blood A material that produces a large acoustic impedance change, which results in a strong reflection, causes a significant reduction in the amount of sound that is available for further transmission through the patient. This may produce an acoustic shadow, which appears as an absence of displayed echoes for structures that are located beneath the interface. Bone, gallstones, calcified plaque, and bowel gas and some image enhancing ultrasound contrast agents can produce acoustic shadows, which fall into one of the categories of ultrasound artifacts.
13 ACOUSTIC COUPLANT Due to the high reflectivity of air, the use of an acoustic couplant is essential. An acoustic couplant is a liquid (oil or gel) that is placed on a patient to insure good contact between the transducer and the skin and to diminish the amount of air that is normally present.
14 TRANSDUCER MATCHING LAYERS Strong reflections could also be present at interfaces between the transducer s piezoelectric elements and the patient s skin. To improve efficiency, increase sensitivity, and minimize internal reflections in the transducer, some transducers incorporate intervening matching layers. The thickness of a matching layer is typically ¼ - wavelength. The acoustic impedance of a matching layer should have a value between the acoustic impedance of the piezoelectric element and the acoustic impedance of tissue. matching layers: materials attached to the front face of a piezoelectric element to reduce reflections at the transducer surface Assuming a transducer has two matching layers between the element and the transducer face, an example of matching could be: Piezoelectric element - acoustic impedance = 30,000,000 rayls First matching layer - acoustic impedance = 16,000,000 rayls Second matching layer - acoustic impedance = 7,000,000 rayls Transducer face material - acoustic impedance = 3,600,000 rayls Acoustic couplant - acoustic impedance = 1,800,000 rayls Skin - acoustic impedance = 1,700,000 rayls
15 SPECULAR REFLECTION Small change or no change in velocity With i normal or oblique, t indicates no refraction Reflections (echoes) most frequently received are those that occur at normal incidence, which is when the interface is perpendicular to the ultrasound beam. Anything other than normal incidence is oblique incidence. According to the Law of Reflection, the angle of incidence, or insonating angle, ( i ) equals the angle of reflection ( r ). Since these two angles are equal, the transducer does not detect reflections that are produced as a result of oblique incidence.
16 SPECULAR REFLECTION Small change or no change in velocity With i normal or oblique, t indicates no refraction Because of oblique incidence, every structure under the transducer is not always visible in an ultrasound display. This is particularly true if the interface is specular (smooth and large compared to the size of an ultrasound wave). Examples of specular interfaces are the diaphragm, the walls of vessels and cystic structures, and the boundaries of many organs.
17 SPECULAR REFLECTION Large increase in velocity With i oblique, refraction is present As sound is transmitted through a specular interface, refraction (as expressed by Snell s Law) may be present. Refraction, which is a change in the direction of the waves transmitted through an interface, is the result of oblique incidence and a significant difference in the velocities of sound in the two materials forming the interface. The transmitted angle ( t ) will be larger than the incident angle in proportion to an increase in the respective velocity.
18 SPECULAR REFLECTION Large decrease in velocity With i oblique, refraction is present The transmitted angle ( t ) will be smaller than the incident angle in proportion to a decrease in the respective velocity. Since ultrasound scanners assume all echoes originate along the original axis of the transmitted beam, refraction can occur without the knowledge of the sonographer. Refraction may cause improper lateral positioning of displayed echoes.
19 SAGITTAL - LIVER, RIGHT KIDNEY N = non-specular reflector S = specular reflector 1 = diaphragm 2 = kidney Interfaces that are either smaller than a wavelength, or not smooth are nonspecular. While specular interfaces reflect sound in only one direction, nonspecular interfaces produce scattering of the sound. Examples of non-specular interfaces include red blood cells, some microbubble contrast agents, liver parenchyma, and many other tissue-like structures. Interfaces that are smaller than a wavelength produce Rayleigh scattering. This type of scattering of sound accounts for the texture that is displayed in an ultrasound image.
20 Answers to the following FOURTEEN practice questions were derived from material in the textbook:
21 Question 1 A range of pulse repetition frequencies in a pulse-echo ultrasound system could be 2,000 Hz to 20,000 Hz 20 MHz to 200 MHz 20,000 Hz to 200,000 Hz 1,200 Hz to 2,000 Hz 2 MHz to 20 MHz Page 9
22 Question 1 A range of pulse repetition frequencies in a pulse-echo ultrasound system could be 2,000 Hz to 20,000 Hz 20 MHz to 200 MHz 20,000 Hz to 200,000 Hz 1,200 Hz to 2,000 Hz 2 MHz to 20 MHz Page 9
23 Question 2 If the number of cycles in a pulse is reduced, the pulse repetition frequency is automatically reduced the spatial pulse length increases the period increases the duty factor is smaller the bandwidth is decreased Pages 6, 7, and 9
24 Question 2 If the number of cycles in a pulse is reduced, the pulse repetition frequency is automatically reduced the spatial pulse length increases the period increases the duty factor is smaller the bandwidth is decreased Pages 6, 7, and 9
25 Question 3 Damping in a transducer reduces the transducer's resonant frequency increases the number of cycles in a pulse causes poor axial and lateral resolution reduces the number of cycles in a pulse Pages 5, 6, 7, and 9
26 Question 3 Damping in a transducer reduces the transducer's resonant frequency increases the number of cycles in a pulse causes poor axial and lateral resolution reduces the number of cycles in a pulse Pages 5, 6, 7, and 9
27 Question 4 The distance to a target is doubled. The total time for a pulse to travel to the target and back is 4 times 2 times 8 times the same halved Page 8
28 Question 4 The distance to a target is doubled. The total time for a pulse to travel to the target and back is 4 times 2 times 8 times the same halved Page 8
29 Question 5 If ultrasound energy leaves a transducer and travels through a large amount of fat and then encounters a reflector, the echo will appear on the display to the right of where it should more superficial than it should deeper than it should to the left of where it should in its correct position Pages 2 and 8
30 Question 5 If ultrasound energy leaves a transducer and travels through a large amount of fat and then encounters a reflector, the echo will appear on the display to the right of where it should more superficial than it should deeper than it should to the left of where it should in its correct position Pages 2 and 8
31 Question 6 The reason most ultrasound systems are calibrated at 1540 meters per second is because 1540 meters per second is the average speed of sound in the patient 1540 meters per second is the speed of sound most often encountered in a patient 1540 meters per second is the maximum speed of sound in a patient 770 meters per second is the average speed of sound in a patient 1540 meters per second is the minimum speed of sound in a patient Pages 2 and 8
32 Question 6 The reason most ultrasound systems are calibrated at 1540 meters per second is because 1540 meters per second is the average speed of sound in the patient 1540 meters per second is the speed of sound most often encountered in a patient 1540 meters per second is the maximum speed of sound in a patient 770 meters per second is the average speed of sound in a patient 1540 meters per second is the minimum speed of sound in a patient Pages 2 and 8
33 Question 7 Which ultrasound system parameter is affected by variations in the speed of sound? pulse repetition frequency pulse repetition period distance accuracy duty factor dynamic range Page 8
34 Question 7 Which ultrasound system parameter is affected by variations in the speed of sound? pulse repetition frequency pulse repetition period distance accuracy duty factor dynamic range Page 8
35 Question 8 Without a perpendicular angle of incidence at a non-specular reflector the bandwidth will increase it is not likely that an echo will return to the transducer Rayleigh scattering is not possible it is possible that an echo will return to the transducer the transmission coefficient will exceed 100% Pages 12, 13, and 14
36 Question 8 Without a perpendicular angle of incidence at a non-specular reflector the bandwidth will increase it is not likely that an echo will return to the transducer Rayleigh scattering is not possible it is possible that an echo will return to the transducer the transmission coefficient will exceed 100% Pages 12, 13, and 14
37 Question 9 If the velocities of sound in the two materials that form an interface are NOT equal, the reflection coefficient will exceed 1 the reflected angle will be greater than the incident angle the transmission coefficient will exceed 1 refraction may occur if the incident angle is not perpendicular the incident angle will be greater than the reflected angle Pages 12 and 13
38 Question 9 If the velocities of sound in the two materials that form an interface are NOT equal, the reflection coefficient will exceed 1 the reflected angle will be greater than the incident angle the transmission coefficient will exceed 1 refraction may occur if the incident angle is not perpendicular the incident angle will be greater than the reflected angle Pages 12 and 13
39 Question 10 The redirection of sound energy in many directions as a result of a rough boundary between two media is shadowing specular reflection through-transmission scattering refraction Page 14
40 Question 10 The redirection of sound energy in many directions as a result of a rough boundary between two media is shadowing specular reflection through-transmission scattering refraction Page 14
41 Question 11 The density is the same in materials A and B, but the speed of sound in material B is 10% greater than the speed of sound in material A. The acoustic impedance in B is 10% greater than the acoustic impedance in A The sound velocity in A is 10% higher than the propagation speed in B The acoustic impedance in A is equal to the acoustic impedance in B The acoustic impedance in A is 10% higher than the acoustic impedance in B The acoustic impedance in B is 2 times the acoustic impedance in A Page 10
42 Question 11 The density is the same in materials A and B, but the speed of sound in material B is 10% greater than the speed of sound in material A. The acoustic impedance in B is 10% greater than the acoustic impedance in A The sound velocity in A is 10% higher than the propagation speed in B The acoustic impedance in A is equal to the acoustic impedance in B The acoustic impedance in A is 10% higher than the acoustic impedance in B The acoustic impedance in B is 2 times the acoustic impedance in A Page 10
43 Question 12 As the impedances of the two media forming an interface become vastly different, the damping increases transmission increases reflection increases bandwidth increases refraction increases Pages 10 and 11
44 Question 12 As the impedances of the two media forming an interface become vastly different, the damping increases transmission increases reflection increases bandwidth increases refraction increases Pages 10 and 11
45 Question 13 A typical reflection coefficient from soft tissue interfaces could be in the range of 75% 1% 20% 40% 50% Page 11
46 Question 13 A typical reflection coefficient from soft tissue interfaces could be in the range of 75% 1% 20% 40% 50% Page 11
47 Question 14 Matching layers in a transducer improve axial resolution provide damping determine the operating frequency provide greater efficiency of sound transmission from the transducer to the patient improve lateral resolution Page 12
48 Question 14 Matching layers in a transducer improve axial resolution provide damping determine the operating frequency provide greater efficiency of sound transmission from the transducer to the patient improve lateral resolution Page 12
2 Basics of Ultrasound Imaging Vincent Chan and Anahi Perlas Introduction... Basic Principles of B-Mode US... Generation of Ultrasound Pulses... Ultrasound Wavelength and Frequency... Ultrasound Tissue
DESIGN AND EVALUATION OF PROBE WITH THREE DEGREE- OF-FREEDOM FOR NON-DESTRUCTIVE TEST USING THREE- DIMENSIONAL FINITE ELEMENT METHOD Masafumi Aoyanagi Graduate School of Systems and Information Engineering,
Ultrasound Basic Idea Send waves into body which are reflected at the interfaces between tissue Return time of the waves tells us of the depth of the reflecting surface History First practical application,
Robot Perception Continued 1 Visual Perception Visual Odometry Reconstruction Recognition CS 685 11 Range Sensing strategies Active range sensors Ultrasound Laser range sensor Slides adopted from Siegwart
LA502 Special Studies Remote Sensing Electromagnetic Radiation (EMR) Dr. Ragab Khalil Department of Landscape Architecture Faculty of Environmental Design King AbdulAziz University Room 103 Overview What
WMO / OMM Autorite du Bassin du Niger Niger-HYCOS and Volta-HYCOS Projects Training programme on flow measurements 2 nd part : Flow measurement techniques Flow measurements and calculations Definitions
STATISTICAL ANALYSIS OF ULTRASOUND ECHO FOR SKIN LESIONS CLASSIFICATION HANNA PIOTRZKOWSKA, JERZY LITNIEWSKI, ELŻBIETA SZYMAŃSKA *, ANDRZEJ NOWICKI Institute of Fundamental Technological Research, Department
Acoustic GHz-Microscopy: Potential, Challenges and Applications A Joint Development of PVA TePLa Analytical Systems GmbH and Fraunhofer IWM-Halle Dr. Sebastian Brand (Ph.D.) Fraunhofer CAM Fraunhofer Institute
Principles of Medical Ultrasound Pai-Chi Li Department of Electrical Engineering National Taiwan University What is Medical Ultrasound? Prevention: actions taken to avoid diseases. Diagnosis: the process
Biophysical principles and clinical applications of MRgFUS Alberto Torresin Struttura Complessa di Fisica Sanitaria Azienda, Milano Università degli Studi di Milano Dip. di Fisica Antonio Rampoldi Struttura
ème Congrès Français d'acoustique Lyon, -6 Avril Finite element simulation of the critically refracted longitudinal wave in a solid medium Weina Ke, Salim Chaki Ecole des Mines de Douai, 94 rue Charles
INSTITUTE OF PHYSICS PUBLISHING Eur. J. Phys. 25 (2004) 581 591 EUROPEAN JOURNAL OF PHYSICS PII: S0143-0807(04)76273-X A wave lab inside a coaxial cable JoãoMSerra,MiguelCBrito,JMaiaAlves and A M Vallera
1 Ny teknologi: Ultralyd måler m blodstrøm Fagdagene ved St. Olavs Hospital Lasse Løvstakken Dept. Circulation and Medical Imaging 11.06.2010 2 Conventional imaging methods of blood flow using ultrasound
COLLATED QUESTIONS: ELECTROMAGNETIC RADIATION 2011(2): WAVES Doppler radar can determine the speed and direction of a moving car. Pulses of extremely high frequency radio waves are sent out in a narrow
Satellite Altimetry Wolfgang Bosch Deutsches Geodätisches Forschungsinstitut (DGFI), München email: firstname.lastname@example.org Objectives You shall recognize satellite altimetry as an operational remote sensing
Rock Bolt Condition Monitoring Using Ultrasonic Guided Waves Bennie Buys Department of Mechanical and Aeronautical Engineering University of Pretoria Introduction Rock Bolts and their associated problems
Optical Design Tools for Backlight Displays Introduction Backlights are used for compact, portable, electronic devices with flat panel Liquid Crystal Displays (LCDs) that require illumination from behind.
Amplification of the Radiation from Two Collocated Cellular System Antennas by the Ground Wave of an AM Broadcast Station Dr. Bill P. Curry EMSciTek Consulting Co., W101 McCarron Road Glen Ellyn, IL 60137,
Christine E. Hatch University of Nevada, Reno Roadmap What is DTS? How Does it Work? What Can DTS Measure? Applications What is Distributed Temperature Sensing (DTS)? Temperature measurement using only
Indian Journal of Geo-Marine Sciences Vol. 40 (2), April 2011, pp. 267-274 Development of EM simulator for sea bed logging applications using MATLAB Hanita Daud 1*, Noorhana Yahya 2, & Vijanth Asirvadam
UNIVERSITY OF SASKATCHEWAN Department of Physics and Engineering Physics Physics 111.6 MIDTERM TEST #4 March 15, 2007 Time: 90 minutes NAME: (Last) Please Print (Given) STUDENT NO.: LECTURE SECTION (please
An Investigationof Non Destructive Testing of Pressure Vessel Mohd Abdul Wahed 1, Mohammed Farhan 2 1,2 Assistant Professor, Departmentof MechanicaL Engineering, Nsakcet,AP-500024 Abstract--Non-Destructive
Steven R. McManus Environmental Product Support Teledyne Isco Flow Measurement Applications and Technologies. Methods of flow measurement Technologies of flow measurement Flow Rate Applications Channel
2 Absorbing Solar Energy 2.1 Air Mass and the Solar Spectrum Now that we have introduced the solar cell, it is time to introduce the source of the energy the sun. The sun has many properties that could
Sixteenth International Water Technology Conference, IWTC 16 2012, Istanbul, Turkey 1 THE USE OF GROUND PENETRATING RADAR WITH A FREQUENCY 1GHZ TO DETECT WATER LEAKS FROM PIPELINES Alaa Ezzat Hasan Ministry
Understanding the Flo-Dar Flow Measuring System Independent tests verify non-contact flowmeter is highly accurate under both open channel and surcharge conditions TM Flo-Dar is the only non-contact open
I. Wireless Channel Modeling April 29, 2008 Qinghai Yang School of Telecom. Engineering email@example.com Qinghai Yang Wireless Communication Series 1 Contents Free space signal propagation Pass-Loss
Index-Velocity Rating Development (Calibration) for H-ADCP Real-Time Discharge Monitoring in Open Channels Hening Huang Teledyne RD Instruments, Inc., 14020 Stowe Drive, Poway, CA. 92064, USA (Tel: 858-842-2600,
Instruction Manual Service Program ULTRA-PROG-IR Parameterizing Software for Ultrasonic Sensors with Infrared Interface Contents 1 Installation of the Software ULTRA-PROG-IR... 4 1.1 System Requirements...
AURA - Analysis Utility for Room Acoustics Merging EASE for sound reinforcement systems and CAESAR for room acoustics Wolfgang Ahnert, S. Feistel, Bruce C. Olson (ADA), Oliver Schmitz, and Michael Vorländer
Wireless Physical Layer Q1. Is it possible to transmit a digital signal, e.g., coded as square wave as used inside a computer, using radio transmission without any loss? Why? It is not possible to transmit
Module 8: IQ: Acquisition Time IQ : Acquisition Time Objectives...Describe types of data acquisition modes....compute acquisition times for 2D and 3D scans. 2D Acquisitions The 2D mode acquires and reconstructs
A Measurement of 3-D Water Velocity Components During ROV Tether Simulations in a Test Tank Using Hydroacoustic Doppler Velocimeter Leszek Kwapisz (*) Marek Narewski Lech A.Rowinski Cezary Zrodowski Faculty
The Acoustics of Indoor Aquatic Facilities: How Improving Sound Levels Impacts Both our Physiological and Psychological Well Being Jeffrey Madison A lifelong musician, Jeff began his career in 1992 when
Dispersion diagrams of a water-loaded cylindrical shell obtained from the structural and acoustic responses of the sensor array along the shell B.K. Jung ; J. Ryue ; C.S. Hong 3 ; W.B. Jeong ; K.K. Shin
CW SERIES PULSE RADAR LEVEL INSTRUMENTS (6.3 GHz) DESCRIPTION The Radar Level Meters of BM COMPACT WAVE 6.3 GHz series are excellent devices for no contact level measurement. The microwave impulses, emitted
Acoustic Doppler Current Profiler Principles of Operation A Practical Primer P/N 951-6069-00 (January 2011) 2011, Inc. All rights reserved. Revision History: January 2011 Corrected Equation 9, page 34.
Lecture 2 How does Light Interact with the Environment? Treasure Hunt Find and scan all 11 QR codes Choose one to watch / read in detail Post the key points as a reaction to http://www.scoop.it/t/env202-502-w2
Finite Element Analysis for Acoustic Behavior of a Refrigeration Compressor Swapan Kumar Nandi Tata Consultancy Services GEDC, 185 LR, Chennai 600086, India Abstract When structures in contact with a fluid
Open Channel & Partially Filled Pipe Ultrasonic Flow Meters DYNAMETERS series DMDF-OP has three types as below: DMDF-OP-A for partially filled pipe application; DMDF-OP-B for partially filled pipe, channel
CHINESE JOURNAL OF PHYSICS VOL. 49, NO. 1 FEBRUARY 2011 Laser-induced surface phonons and their excitation of nanostructures Markus Schmotz, 1, Dominik Gollmer, 1 Florian Habel, 1 Stephen Riedel, 1 and
Fundamentals of Electromagnetic Fields and Waves: I Fall 2007, EE 30348, Electrical Engineering, University of Notre Dame Mid Term II: Solutions Please show your steps clearly and sketch figures wherever
Which physics for full-wavefield seismic inversion? M. Warner* (Imperial College London), J. Morgan (Imperial College London), A. Umpleby (Imperial College London), I. Stekl (Imperial College London) &
2 nd International Symposium on Seawater Drag Reduction Busan, Korea, 23-26 MAY 2005 Micro-Optical Sensor Use in Boundary Layer Flows with Polymers and Bubbles D. Modarress, P. Svitek (Measurement Science
SITE IMAGING MANUAL ACRIN 6698 Diffusion Weighted MR Imaging Biomarkers for Assessment of Breast Cancer Response to Neoadjuvant Treatment: A sub-study of the I-SPY 2 TRIAL Version: 1.0 Date: May 28, 2012
ENVIRONMENT, SAFETY & HEALTH DIVISION Chapter 50: Non-ionizing Radiation Selected Radio Frequency Exposure Limits Product ID: 94 Revision ID: 1736 Date published: 30 June 2015 Date effective: 30 June 2015
Index-Velocity Rating Development for Rapidly Changing Flows in an Irrigation Canal Using Broadband StreamPro ADCP and ChannelMaster H-ADCP HENING HUANG, RD Instruments, 9855 Businesspark Avenue, San Diego,
Light Control and Efficacy using Light Guides and Diffusers LEDs 2012 Michael Georgalis, LC Marketing Manager, Fusion Optix October 11, 2012 Agenda Introduction What Is Light Control? Improves Application
GCE Applied Science Advanced GCE Unit G635: Working Waves Mark Scheme for January 2012 Oxford Cambridge and RSA Examinations OCR (Oxford Cambridge and RSA) is a leading UK awarding body, providing a wide
HYDROGRAPHIC ECHOSOUNDER FOR SOUNDING INLAND WATERS ANDRZEJ JEDEL, LECH KILIAN, JACEK MARSZAL, ZAWISZA OSTROWSKI, ZBIGNIEW WOJAN, KRZYSZTOF ZACHARIASZ Gdańsk University of Technology, Faculty of Electronics,
Statistical Energy Analysis software Development and implementation of an open source code in Matlab/Octave Master s Thesis in the Master s programme in Sound and Vibration DANIEL JOHANSSON PETER COMNELL
Physics 6C, Summer 006 Homework Solutions All problems are from the nd edition of Walker. Numerical values are different for each student. Chapter 3 Problems. Figure 3-30 below shows a circuit containing
ODEON Workshop, Mariehamn, Åland, Finland, 2nd June 2004 ODEON and the scattering coefficient Jens Holger Rindel Specular and diffuse reflection Reflection models (asymptotic models for short wavelengths)
1 2 The range of RF spans 3 KHz (3000 Hz) to 300 GHz (300 million Hz) Frequencies of RF devices range from the low frequency AM broadcasts (80 MHz) to higher frequency mobile phones (1900 MHz) smart meters
Specific Intensity Initial question: A number of active galactic nuclei display jets, that is, long, nearly linear, structures that can extend for hundreds of kiloparsecs. Many have two oppositely-directed
Proc. of 1st IEEE Conf. on Nanotechnology, Oct. 28-3, pp. 495-5, (21) Maui, Hawaii Nano Meter Stepping Drive of Surface Acoustic Wave Motor Takashi Shigematsu*, Minoru Kuribayashi Kurosawa*, and Katsuhiko
Spectrum Level and Band Level ntensity, ntensity Level, and ntensity Spectrum Level As a review, earlier we talked about the intensity of a sound wave. We related the intensity of a sound wave to the acoustic
Sonic Logging in Deviated Boreholes of an Anisotropic Formation: Laboratory Study Zhenya Zhu, Shihong Chi, and M. Nafi Toksöz Earth Resources Laboratory Dept. of Earth, Atmospheric, and Planetary Sciences
AP Physics 1 and 2 Lab Investigations Student Guide to Data Analysis New York, NY. College Board, Advanced Placement, Advanced Placement Program, AP, AP Central, and the acorn logo are registered trademarks
Near real-time transmission of reduced data from a moored multi-frequency sonar by low bandwidth telemetry Rene A.J. Chave, David D. Lemon, Jan Buermans ASL Environmental Sciences Inc. Victoria BC Canada
8 Room and Auditorium Acoustics Acoustical properties of rooms and concert halls are mainly determined by the echo that depends on the reflection and absorption of sound by the walls. Diffraction of sound
1602 PIERS Proceedings, Marrakesh, MOROCCO, March 20 23, 2011 Human Exposure to Outdoor PLC System Vicko Doric 1, Dragan Poljak 1, and Khalil El Khamlichi Drissi 2 1 University of Split, Croatia 2 Blaise
LS-296 Vector Network Analyzer Techniques to Measure WR340 Waveguide Windows T. L. Smith ASD / RF Group Advanced Photon Source Argonne National Laboratory June 26, 2002 Table of Contents 1) Introduction
Physics 202 Problems - Week 8 Worked Problems Chapter 25: 7, 23, 36, 62, 72 Problem 25.7) A light beam traveling in the negative z direction has a magnetic field B = (2.32 10 9 T )ˆx + ( 4.02 10 9 T )ŷ
Acoustics 8 Paris Plate waves in phononic crystals slabs J.-J. Chen and B. Bonello CNRS and Paris VI University, INSP - 14 rue de Lourmel, 7515 Paris, France firstname.lastname@example.org 41 Acoustics 8 Paris We
Environmental Effects On Phase Coherent Underwater Acoustic Communications: A Perspective From Several Experimental Measurements T. C. Yang, Naval Research Lab., Washington DC 20375 Abstract. This paper
Data Transmission Concepts and terminology Transmission terminology Transmission from transmitter to receiver goes over some transmission medium using electromagnetic waves Guided media. Waves are guided
Clinical Physics Dr/Aida Radwan Assistant Professor of Medical Physics Umm El-Qura University Physics of Radiotherapy using External Beam Dose distribution PHANTOMS Basic dose distribution data are usually
Antenna Properties and their impact on Wireless System Performance Dr. Steven R. Best Cushcraft Corporation 48 Perimeter Road Manchester, NH 03013 Phone (603) 627-7877 FAX: (603) 627-1764 Email: email@example.com
Renal cell cancer Renal cell cancer is a disease in which malignant (cancer) cells form in tubules of the kidney. Renal cell cancer (also called kidney cancer or renal adenocarcinoma) is a disease in which
ME 472 Engineering Metrology and Quality Control Chp 6 - Advanced Measurement Systems Mechanical Engineering University of Gaziantep Dr. A. Tolga Bozdana Assistant Professor Coordinate Measuring Machines
EM Implosion Memos Memo 51 July, 2010 Experimental results for the focal waveform and beam width in the focusing lens with a 100 ps filter Prashanth Kumar, Carl E. Baum, Serhat Altunc, Christos G. Christodoulou
Specifications and description HRTL 3B Laser diffuse reflection light scanner with background suppression Dimensioned drawing We reserve the right to make changes DS_HRTL3B_en.fm en 01-2010/12 50114049
DOING PHYSICS WITH MATLAB COMPUTATIONAL OPTICS RAYLEIGH-SOMMERFELD DIFFRACTION INTEGRAL OF THE FIRST KIND THE THREE-DIMENSIONAL DISTRIBUTION OF THE RADIANT FLUX DENSITY AT THE FOCUS OF A CONVERGENCE BEAM
Twelve The 3D Curved MPR Viewer This Chapter describes how to visualize and reformat a 3D dataset in a Curved MPR plane: Curved Planar Reformation (CPR). The 3D Curved MPR Viewer is a window opened from
Finesse Enhancement Factors Steve Adler, IAS, 2/29/06; expanded /4/08 First, the definition of finesse. From Encyclopedia of Laser Physics and Technology, article on Finesse, htp://www.rp-photonics.com/finesse.html,
Optical Coherence Tomography detection of shear wave propagation in layered tissue equivalent phantoms Marjan Razani 1, Adrian Mariampillai 2,Peter Siegler 2,Victor X.D. Yang 2,3, Michael C. Kolios 1,*
90732 3 907320 For Supervisor s Level 3 Science, 2008 90732 Describe selected properties and applications of EMR, radioactive decay, sound and ultrasound Credits: Four 2.00 pm Thursday 20 November 2008
SUMMARY HEMODYNAMIC MONITORING: FROM PRINCIPLES TO PRACTICE Michael L. Cheatham, MD, FACS, FCCM Director, Surgical Intensive Care Units Orlando Regional Medical Center Orlando, Florida Fluid-filled catheters
Building Design for Advanced Technology Instruments Sensitive to Acoustic Noise Michael Gendreau Colin Gordon & Associates Presentation Outline! High technology research and manufacturing instruments respond
2013 WJTA-IMCA Conference and Expo September 9-11, 2013 Houston, Texas Paper REFRACTORY REMOVAL BY HIGH PRESSURE WATERJET D. Wright StoneAge, Inc. Durango, Colorado, U.S.A. ABSTRACT The removal of refractory
Your consent to our cookies if you continue to use this website.