Front Cover 1
Power Ultrasonics: Applications of High-intensity Ultrasound 4
Copyright 5
Contents 6
List of contributors 18
Woodhead Publishing Series in Electronic and Optical Materials 22
Chapter 1: Introduction to power ultrasonics 26
1.1. Introduction 26
1.2. The field of ultrasonics 26
1.3. Power ultrasonics 27
1.4. Historical notes 28
1.5. Coverage of this book 29
Part One: Fundamentals 32
Chapter 2: High-intensity ultrasonic waves in fluids: nonlinear propagation and effects 34
2.1. Introduction 34
2.2. Nonlinear phenomena 35
2.2.1. Basic equations: acoustic, entropy, and vorticity modes 35
2.2.2. Scope of nonlinear acoustics 37
2.3. Nonlinear interactions within the acoustic mode 38
2.3.1. Simple waves 38
2.3.2. Quadratic approximation 41
2.3.3. Nonlinear distortion and shock formation 42
2.3.4. Shock structure 44
2.3.5. Intense acoustic fields radiated by finite-aperture sources 45
2.3.6. Formation of high-intensity ultrasound fields using focusing 47
2.4. Nonlinear interactions between the acoustic and nonacoustic modes 49
2.4.1. General remarks 49
2.4.2. Acoustic streaming and radiation force 50
2.4.3. Medium heating due to absorption of acoustic waves 53
2.4.4. Heat release at a shock 55
2.5. Conclusion 57
Chapter 3: Acoustic cavitation: bubble 
 
62 
3.1. Introduction 62
3.2. Cavitation thresholds 63
3.2.1. Static tension threshold 63
3.2.2. Acoustic cavitation threshold 64
3.3. Single-bubble dynamics 65
3.3.1. Bubble models 66
3.3.2. Response curves 71
3.3.2.1. Low driving 71
3.3.2.2. High driving 73
3.3.3. Parameter space diagrams 75
3.3.4. Bubble habitat 76
3.3.5. Single-bubble dynamics: examples 78
3.3.5.1. Sound radiation 78
3.3.5.2. Deformation, splitting, and merging 79
3.3.5.3. Jet formation 80
3.4. Bubble ensemble dynamics 80
3.4.1. Bubble clusters 82
3.4.2. Bubble filaments 84
3.4.3. Bubble double layers 85
3.4.4. Bubble cones 86
3.4.5. N-bubble model 87
3.4.6. N-bubble simulation examples 88
3.5. Acoustic cavitation noise 90
3.5.1. Subharmonics and period doubling 90
3.5.2. Synchronization 92
3.5.3. Bubble splitting 93
3.6. Sonoluminescence 94
3.7. Conclusions 96
Chapter 4: High-intensity ultrasonic waves in solids: nonlinear dynamics 
104 
4.1. Introduction 104
4.2. Fundamental nonlinear equations 104
4.2.1. Constitutive equations and equation of motion 104
4.2.2. Approximate analytical solutions 107
4.2.2.1. Applications 109
4.2.3. Isotropic solids and wave number modulation 111
4.2.3.1. Applications 112
4.3. Nonlinear effects in progressive and stationary waves 113
4.3.1. Harmonic balance in progressive waves: dispersion and attenuation 113
4.3.2. Frequency mixing 115
4.3.2.1. Applications 116
4.3.3. Stationary waves: nonlinear sources 117
4.3.3.1. Applications 121
4.4. Conclusions 122
Chapter 5: Piezoelectric ceramic materials for power ultrasonic transducers 126
5.1. Introduction 126
5.2. Fundamentals of ferro-piezoelectric ceramics 126
5.2.1. From the ferroelectric single-crystal to the ceramic 126
5.2.2. Ferroelectric hysteresis and domains 129
5.2.3. The poling process 130
5.2.4. Multifunctional ferro-piezoelectric ceramics 131
5.3. Characterization methods of ceramics from piezoelectric resonances 132
5.3.1. IEEE and European standard methods 133
5.3.2. Alternative numerical methods, a review 135
5.3.3. The iterative automatic method 136
5.4. Applications of the iterative automatic method in the characterization of ceramics 137
5.4.1. Thin disk resonator, thickness poled 138
5.4.2. Shear plate resonator, thickness poled 140
5.4.3. Long bar resonator, length poled 140
5.4.4. Using finite element analysis to check the validity of characterization 140
5.5. Lead-free piezoceramics for environmental protection 142
5.5.1. Aurivillius-type structure ceramics 142
5.5.2. Alkaline niobates 143
5.5.3. Bismuth-sodium titanates 143
5.6. Future trends 144
Chapter 6: Power ultrasonic transducers: principles and design 152
6.1. Introduction 152
6.2. Ultrasonic vibrations: mechanical oscillator 153
6.2.1. Summary of vibration results 153
6.2.1.1. Free vibration of an undamped oscillator 154
6.2.1.2. Free vibration of a damped oscillator 155
6.2.1.3. Forced vibration of an undamped oscillator 155
6.2.1.4. Forced vibration of a damped oscillator 157
6.2.1.5. A note on transient response 157
6.2.2. Equivalent circuit, impedance 158
6.2.3. Displacement/velocity forcing, parallel equivalent circuit 160
6.3. Ultrasonic vibrations: longitudinal vibrations 161
6.3.1. Governing theory, natural frequencies 161
6.3.2. Forced vibrations of a rod 164
6.3.3. Three-dimensional effects 166
6.3.4. Ultrasonic horns 167
6.3.5. Equivalent circuit 168
6.3.6. Summary of basic vibrations 169
6.4. Piezoelectric materials 169
6.5. The power ultrasonic transducer 171
6.5.1. Basic transducer 171
6.5.2. Practical design considerations 171
6.5.3. Other configurations 173
6.6. Transducer characterization and control 174
6.6.1. Transducer impedance: equivalent circuit 174
6.6.2. Ultrasonic transducer systems 175
6.6.2.1. Impedance matching 176
6.6.2.2. Frequency control 176
6.6.2.3. Amplitude control 177
6.6.3. Power 178
6.7. Modeling transducer behavior 179
6.8. Transducer development 181
6.9. Future trends 182
6.10. Sources of further information and advice 182
Chapter 7: Power ultrasonic transducers with vibrating plate radiators* 184
7.1. Introduction 184
7.2. Structure of transducers: basic design 184
7.3. Finite element modeling 187
7.4. Controlling nonlinear vibration behavior 190
7.4.1. Nonlinear piezoelectric responses 191
7.4.2. Modal interactions 194
7.5. Fatigue limitations of transducers 199
7.6. Characteristics of the different types of plate transducers 201
7.6.1. Stepped-plate transducers 201
7.6.2. Grooved-plate transducers 205
7.6.3. Stepped-grooved plate transducers 208
7.6.4. Flat plate transducers with reflectors 208
7.7. Evaluating transducers in power operation: electrical, vibrational, acoustic, and thermal characteristics 211
7.8. Conclusions and future trends 216
Chapter 8: Measurement techniques in power ultrasonics 220
8.1. Introduction 220
8.2. Characterizing the source 222
8.2.1. Electrically 222
8.2.2. Optically: vibrometry and microscopy 222
8.3. Characterizing the generated ultrasound field 223
8.3.1. Acoustic power: bulk assessment 223
8.3.2. Acoustic pressure and intensities: local assessment 224
8.4. Characterizing the resultant acoustic cavitation 225
8.4.1. Scoping the challenge 225
8.4.2. Acoustical methods 226
8.4.3. Chemical methods 230
8.4.4. Optical methods 231
8.4.5. Mechanical methods 232
8.5. Case studies: characterizing two cavitating systems 233
8.6. Conclusions 238
Chapter 9: Modeling of power ultrasonic transducers 244
9.1. Introduction 244
9.2. Transduction and elastic wave propagation in solids 244
9.2.1. Physical equations and boundary conditions 244
9.2.2. Finite element method (FEM) 246
9.2.2.1. Variational formulation 246
9.2.2.2. Space discretization 247
9.2.2.3. Problem types 249
Three types of analyses are considered 249
9.2.3. Illustrative examples 250
9.2.3.1. Length expander transducer 250
9.2.3.2. Ultrasonic motor 250
9.3. Acoustic waves in fluids and fluid-structure coupling 253
9.3.1. Physical equations and boundary conditions 253
9.3.2. FEM 253
9.4. The unbounded problem: far-field radiation of acoustic waves 255
9.4.1. Methods based on exact nonlocal boundary conditions 255
9.4.1.1. Exact nonlocal boundary conditions 255
9.4.1.2. Boundary element method (BEM) 256
9.4.1.3. Dirichlet-to-Neuman (DtN) method 258
9.4.2. Methods based on approximate boundary conditions 259
9.4.2.1. Acoustic dampers 259
9.4.2.2. Perfectly matched layers (PMLs) 260
9.4.3. Illustrative example: airborne stepped plate transducer 260
Chapter 10: Modeling energy losses in power ultrasound transducers 266
10.1. Introduction 266
10.2. Modeling linear and nonlinear behavior 267
10.2.1. Linear case: coupled equations 267
10.2.2. Nonlinear case 270
10.3. Experimental validation and simulation testing 273
10.4. Assessing model performance 277
10.5. Conclusions 278
Part Two: Welding, metal forming, and machining applications 282
Chapter 11: Ultrasonic welding of metals 284
11.1. Introduction 284
11.2. Principles of ultrasonic metal welding 285
11.2.1. Ultrasonic frequency 291
11.2.2. Vibration amplitude 291
11.2.3. Static force 292
11.2.4. Power, energy, and time 292
11.2.5. Materials 293
11.2.6. Part geometry 294
11.2.7. Tooling 294
11.3. Ultrasonic welding equipment 294
11.4. Mechanics and metallurgy of the ultrasonic weld 297
11.5. Applications of ultrasonic welding 309
11.6. Process advantages and disadvantages 311
Advantages 311
Disadvantages 312
11.6.1. Solid-state welding process 312
11.6.2. Aluminum, copper, other materials 312
11.6.3. Dissimilar materials 312
11.6.4. Thin-thick combinations 313
11.6.5. Oxides and contaminants 313
11.6.6. Fast, easily automated 313
11.6.7. Filler metals and gases 314
11.6.8. Low energy requirements 314
11.6.9. Restricted to lap joints 314
11.6.10. Limited in joint thickness and material hardness 314
11.6.11. Material-part deformation 314
11.6.12. Noise 315
11.6.13. Process unfamiliarity 315
11.7. Future trends 315
11.7.1. More powerful welding systems 315
11.7.2. Process controls and systems 316
11.7.3. Mechanism of ultrasonic welding 316
11.7.4. Joint types 316
11.8. Sources of further information and advice 317
Chapter 12: Ultrasonic welding of plastics and polymeric composites 320
12.1. Introduction 320
12.2. Theory of the ultrasonic welding process 320
12.2.1. Viscoelastic heating of polymers 322
12.2.2. Near-field ultrasonic welding 324
12.2.3. Far-field ultrasonic welding 324
12.3. Description of plunge and continuous welding processes 326
12.3.1. Plunge welding 326
12.3.2. Continuous and scan welding 327
12.3.3. Process control 329
12.4. Ultrasonic welding equipment 329
12.4.1. Power supply and controller 330
12.4.2. Ultrasonic stack 330
12.4.3. Actuator 332
12.4.4. Fixture 333
12.5. Joint and part design 333
12.6. Material weldability 335
Chapter 13: Power ultrasonics for additive manufacturing and consolidating of materials 338
13.1. Introduction 338
13.1.1. Steps necessary for moving from computer data to part via additive manufacturing (AM) 338
13.1.1.1. Step 1: Computer-aided design (CAD) 3-D model creation 338
13.1.1.2. Step 2: .stl file conversion 339
13.1.1.3. Step 3: Build setup of specific AM machine 340
13.1.1.4. Step 4: Manufacture of the component via specific AM process 340
13.1.1.5. Step 5: Postprocessing of components 340
13.1.2. Additive manufacturing process categories 341
13.2. Ultrasonic additive manufacturing 342
13.2.1. System components 343
13.2.1.1. Benefits of ultrasonic welding 344
13.2.1.2. Power supply 344
13.2.1.3. Transducer 345
13.2.1.4. Booster 345
13.2.1.5. Sonotrode 345
13.2.1.6. Anvil 345
13.2.1.7. System setup 346
13.2.2. Process operation 346
13.2.2.1. Weld speed 347
13.2.2.2. Sonotrode oscillation amplitude 347
13.2.2.3. Weld pressure 348
13.2.2.4. Anvil temperature 348
13.2.2.5. Sonotrode topology 348
13.2.3. Development of a higher power system 349
13.3. Applications of ultrasonic additive manufacturing 351
13.3.1. Complicated geometry 351
13.3.2. Dissimilar material bonding 351
13.3.3. Object embedment 353
13.4. Future trends 356
13.5. Conclusion 357
Chapter 14: Ultrasonic metal forming: Materials 362
14.1. Introduction 362
14.2. Microstructure effects 363
14.3. Macroscopic behavior 364
14.3.1. Early developments 365
14.3.2. The 1970s and 1980s 372
14.3.3. The 1990s to the present 374
14.4. Surface friction 381
14.4.1. Early developments 382
14.4.2. The 1980s to the present 388
14.5. Future trends 394
14.6. Sources of further information and advice 394
Chapter 15: Ultrasonic metal forming: Processing 402
15.1. Introduction 402
15.2. Wire and tube drawing 402
15.2.1. Early developments 403
15.2.2. The 1970s and 1980s 409
15.2.3. The 1990s to the present 411
15.3. Deep drawing and bending 418
15.3.1. Deep drawing 418
15.3.1.1. The early years: 1960s and 1970s 418
15.3.1.2. The 1980s to the present 422
15.3.2. Bending 429
15.4. Forging and extrusion 429
15.4.1. Early developments 429
15.4.2. Recent developments 434
15.5. Ultrasonic rolling 439
15.6. Other forming processes 441
15.6.1. Shearing and blanking 442
15.6.2. Tube expansion 443
15.6.3. Wire flattening 443
15.6.4. Riveting 444
15.6.5. Surface treatment 445
15.6.6. Microforming 449
15.6.7. Compaction 451
15.7. Future trends 455
15.8. Sources of further information and advice 456
Chapter 16: Using power ultrasonics in machine tools 464
16.1. Introduction 464
16.2. Historical and technical review 466
16.2.1. Surface grinding 466
16.2.2. Turning 468
16.2.3. Reaming 471
16.2.4. Milling 471
16.2.5. Drilling 471
16.2.6. Machining/forming 473
16.3. Ultrasonic machine tool processes: ultrasonic turning 476
16.3.1. Ultrasonic cutting modes 477
16.3.2. Mechanism of ultrasonic turning 478
16.3.3. Systems hardware 481
16.3.4. Ultrasonic turning data 482
16.3.4.1. Turning speeds and machining practice 483
16.3.4.2. Surface quality 484
16.3.4.3. DOC and feed rate 487
16.3.4.4. Tool wear 487
16.3.4.5. Chip morphology 488
16.3.4.6. Coolants 488
16.3.4.7. Cutting forces 492
16.3.4.8. Elliptical vibration cutting 495
16.4. Ultrasonic drilling and milling 497
16.4.1. Drilling 497
16.4.2. Milling 507
16.5. Ultrasonic grinding 513
16.6. Allied ultrasonic machining processes 517
16.6.1. Reaming, honing, lapping 517
16.6.2. Tapping 518
16.6.3. Other 519
16.7. Ultrasonic machine tools for production 520
16.7.1. Basic drill press 520
16.7.2. Heavy-duty portable drill 520
16.7.3. Ultrasonic tool attachments and module 523
16.7.4. Machining center adaptation 525
16.8. Future trends 526
16.9. Sources of further information and advice 527
Part Three: Engineering and medical applications 534
Chapter 17: Ultrasonic motors 536
17.1. Introduction 536
17.2. Traveling-wave ultrasonic motors 537
17.2.1. Principle of the traveling-wave linear ultrasonic motor 537
17.2.2. Variations of the traveling-wave linear ultrasonic motor 538
17.2.3. Traveling-wave rotary motors: ring or disk shape 539
17.2.4. Traveling-wave rotary motors: bar shape 541
17.3. Hybrid transducer ultrasonic motors 543
17.3.1. Hybrid transducer linear motors 543
17.3.2. High-power hybrid transducer linear motors 548
17.3.3. Hybrid transducer rotary motors 553
17.4. Performance of ultrasonic motors and driver circuits 558
17.4.1. Equivalent circuit modeling 559
17.4.2. Discussion of motor performance 561
17.4.3. Driving circuits for ultrasonic motors 563
17.5. Conclusion and future trends 564
Chapter 18: Power ultrasound for the production of nanomaterials 568
18.1. Introduction 568
18.2. Ultrasound synthesis of metallic nanoparticles 570
18.3. Ultrasound synthesis of metal oxide nanoparticles 573
18.4. Ultrasound synthesis of chalcogenide nanoparticles 581
18.5. Ultrasound synthesis of metal halide nanoparticles 582
18.5.1. Ultrasound synthesis of water-insoluble metal halides 582
18.5.2. Ultrasound synthesis of water-soluble metal halides 584
18.6. Using ultrasonic waves in the synthesis of graphene, graphene oxide, and other nanomaterials 584
18.6.1. Ultrasound synthesis of miscellaneous nanoparticles 586
18.7. The use of ultrasound for the deposition of nanoparticles on substrates 586
18.8. Ultrasound synthesis of micro- and nanospheres 589
18.9. Conclusions and future trends 594
Chapter 19: Ultrasonic cleaning and washing of surfaces 602
19.1. Introduction 602
19.2. The use of ultrasound in cleaning 603
19.3. Ultrasonic cleaning technology 604
19.3.1. Transducers 604
19.3.2. Generators 606
19.3.3. Factors driving development 606
19.4. Mechanism of ultrasonic cleaning 606
19.4.1. Cavitation 607
19.4.2. Cleaning 607
19.5. Ultrasonic cleaning process variables 608
19.5.1. Size and number of cavitation bubbles 608
19.5.2. The effect of temperature and chemistry on liquid properties 608
19.5.3. Viscosity 609
19.5.4. Surface tension 609
19.5.5. Dissolved gas and its diffusion rate 609
19.5.6. Vapor pressure 610
19.5.7. Ultrasonic power 610
19.5.8. Ultrasonic frequency 611
19.6. The role of chemical additives and temperature 611
19.7. Achieving optimum ultrasonic cleaning performance 612
19.7.1. Degassing 612
19.7.2. Ultrasonic power 612
19.7.3. Part exposure 613
19.7.4. Liquid agitation 614
19.8. Evaluating ultrasonic cleaning performance 614
19.8.1. Chlorine release test 615
19.8.2. Standardized soil test 615
19.8.3. Aluminum foil test 616
19.8.4. Ceramic ring test 617
19.8.5. Hydrophones 618
19.8.6. Lead erosion 619
19.8.7. Calorimetric test 619
19.8.8. Test validity 619
19.9. Advances in technology 620
19.9.1. Ultrasonic transducers 620
19.9.2. Ultrasonic generators 621
19.9.2.1. Sweep 621
19.9.2.2. Higher frequency 622
19.10. Damage mechanisms 623
19.10.1. Cavitation erosion or ``burning´´ 623
19.10.2. Mechanical resonance 623
19.11. Megasonics 624
19.12. Future trends 626
19.12.1. Higher frequency 626
19.12.2. Cost 626
19.12.3. Future applications 626
19.13. Sources of further information and advice 627
Appendix: 
627 
Chapter 20: Ultrasonic degassing of liquids 636
20.1. Introduction 636
20.2. Fundamentals of ultrasonic degassing 638
20.2.1. General mechanisms 638
20.2.2. Cavitation and degassing nuclei 639
20.3. Mechanism of ultrasonic degassing in melts 642
20.4. Main process parameters in ultrasonic degassing 645
20.4.1. Ultrasonic energy 648
20.4.2. Melt temperature 648
20.4.3. Inclusions 648
20.4.4. Alloy composition 649
20.4.5. Treatment time and volume 649
20.5. Industrial implementation of ultrasonic degassing 649
Chapter 21: Ultrasonic surgical devices and procedures 658
21.1. Introduction 658
21.2. Surgical device requirements and goals 658
21.2.1. Historical overview 658
21.2.2. Target tissues 660
21.2.2.1. Soft tissues 660
21.2.2.2. Hard tissues 660
21.2.3. Surgical requirements 661
21.3. General device design 661
21.3.1. Resonance as the fundamental design concept 661
21.3.2. Key components: generator, transducer, horn, probe, and wire 662
21.3.2.1. Generator 662
21.3.2.2. Transducer 663
21.3.2.3. Coupler/horn 663
21.3.2.4. Transmission element/probe/wire 664
21.3.2.5. End effector 664
21.3.3. Modes of operation 665
21.3.3.1. Longitudinal 665
21.3.3.2. Torsional 666
21.3.3.3. Lateral and ellipsoidal 666
21.3.3.4. Compound motions 667
21.3.3.5. Wire transverse 667
21.3.3.6. Unwanted modes 667
21.3.4. End effectors 668
21.3.4.1. Solid end effectors 668
21.3.4.2. Hollow end effectors 668
21.3.4.3. Wires 668
21.3.4.4. Bends and shapes 669
21.3.5. Ancillary concerns 669
21.3.5.1. Irrigation and aspiration 669
21.3.5.2. Physician interaction 670
21.4. Mechanisms of action 670
21.4.1. Cavitation 670
21.4.1.1. Cavitation nuclei and rectified diffusion 670
21.4.1.2. Transient cavitation 671
21.4.1.3. Stable cavitation 672
21.4.2. Direct impact 672
21.4.3. Thermal 673
21.4.4. Acoustic energy, acoustic streaming, and radiation force 673
21.4.4.1. Acoustic pressure and power 673
21.4.4.2. Acoustic radiation force and streaming 674
21.4.5. Nebulization 674
21.5. Device types 675
21.5.1. Aspiration devices: open surgery 675
21.5.1.1. The CUSA and derivative devices 675
21.5.1.2. Contact debridement 675
21.5.1.3. Phacoemulsification devices 675
21.5.1.4. Bone cutting 677
21.5.2. Cutting/coagulation devices: the Harmonic Scalpel and derivative devices 677
21.5.3. Remote disruptive devices 677
21.5.4. Tissue-preserving devices 678
21.5.5. Externally applied devices 678
21.5.6. Focused ultrasound devices: high-intensity focused ultrasound 678
21.6. Medical device regulations 679
21.6.1. General requirements 679
21.6.2. IEC Standards pertaining to ultrasonic surgical devices 679
21.7. Future trends 679
21.8. Sources of further information and advice 680
Chapter 22: High-intensity focused ultrasound for medical therapy 686
22.1. Introduction 686
22.2. Ultrasound interaction with tissue 687
22.2.1. Thermal interaction 687
22.2.1.1. Energy absorption 687
22.2.1.2. Thermal ablation 688
22.2.1.3. Apoptosis 690
22.2.1.4. Hyperthermia 690
22.2.2. Cavitational interaction 691
22.2.2.1. Mechanism 691
22.2.2.2. Tissue disintegration and fragmentation 693
22.2.2.3. Enhancement of drug treatments 693
22.2.3. Radiation force 694
22.3. Therapy devices 694
22.3.1. External devices 695
22.3.2. Endocavity devices 699
22.3.3. Interstitial and intraoperative devices 701
22.4. Imaging guidance 701
22.4.1. Ultrasound 701
22.4.2. Magnetic resonance imaging 703
22.4.3. Other imaging modalities 705
22.5. Clinical experience 705
22.5.1. Prostate 705
22.5.2. Liver 706
22.5.3. Breast 706
22.5.4. Uterine fibroids 707
22.5.5. Thyroid 708
22.5.6. Bone 709
22.5.7. Brain 709
22.5.8. Stroke 710
22.6. Future trends 710
Chapter 23: Ultrasonic cutting for surgical applications 720
23.1. Introduction: the origins of ultrasonic cutting for surgical devices 720
23.2. Developments in ultrasound for soft-tissue dissection 722
23.3. Developments in ultrasound for bone cutting and other surgical applications 725
23.4. Cutting mechanisms in soft tissue 726
23.5. Ultrasonic dissection of mineralized tissue 727
23.6. Factors affecting device performance 729
23.6.1. Temperature control 729
23.6.2. Multiple-mode devices 730
23.6.3. Nonlinear and undesirable behavior 731
23.7. Device characterization 733
23.7.1. Modal analysis 733
23.7.2. Harmonic characterization 735
23.8. Orthopedic, orthodontic, and maxillofacial procedures 737
23.8.1. Selective cutting 737
23.8.2. A clinical procedure using ultrasonic devices 738
23.9. Current and future trends 740
23.9.1. Transduction materials 740
23.9.2. Transducer design 740
23.9.3. Planar transducers 740
23.9.4. Flextensional transducers 741
Part Four: Food technology and pharmaceutical applications 748
Chapter 24: Design and scale-up of sonochemical reactors for food processing and other applications 750
24.1. Introduction 750
24.2. Modeling of cavitational reactors 751
24.3. Understanding cavitational activity 753
24.4. Types of reactors 758
24.4.1. Probe systems 759
24.4.2. Ultrasonic baths 759
24.4.3. Flow systems 760
24.5. Developments in reactor design 762
24.6. Selecting operating parameters 771
24.6.1. Selection of frequency of irradiation 772
24.6.2. Selection of power dissipation levels 772
24.6.3. Liquid phase physicochemical properties 774
24.6.4. Geometrical design of the reactor 774
24.7. Reactor choice, scale-up, and optimization 775
24.8. Future trends 776
24.9. Conclusions 777
Chapter 25: Ultrasonic mixing, homogenization, and emulsification in food processing and other applications 782
25.1. Introduction 782
25.2. Cavitation and acoustic streaming 783
25.2.1. Acoustic cavitation 783
25.2.2. Acoustic streaming 784
25.2.3. Conclusion 785
25.3. Mixing 785
25.3.1. Macromixing 785
25.3.2. Micromixing 786
25.4. Particle and aggregate dispersion and disruption 789
25.4.1. Dispersion or deagglomeration 789
25.4.2. Disruption and breakage 791
25.5. Solid and liquid dissolution 794
25.6. Homogenization 800
25.7. Emulsification 803
25.7.1. Specific aspects of US emulsification 804
25.7.2. Main features of US emulsification 805
25.8. Conclusions and future trends 810
Chapter 26: Ultrasonic defoaming and debubbling in food processing and other applications 818
26.1. Introduction 818
26.2. Foams 819
26.2.1. Types and characteristics 819
26.2.2. Effects of foam in processes 820
26.3. Conventional methods for foam control 821
26.4. Ultrasonic defoaming 822
26.5. Mechanisms of ultrasonic defoaming 824
26.6. Ultrasonic defoamers 828
26.7. Using ultrasound to remove bubbles in coating layers 836
26.8. Conclusions and future trends 837
Chapter 27: Power ultrasonics for food processing 840
27.1. Introduction 840
27.2. Ultrasonically assisted extraction (UAE) 841
27.2.1. Essential oils and aromas 842
27.2.2. Antioxidants and colors 845
27.3. Emulsification 846
27.4. Viscosity modification 849
27.5. Processing dairy proteins 851
27.6. Sonocrystallization 854
27.7. Fat separation 859
27.8. Other applications: sterilization, pasteurization, drying, brining, and marinating 860
27.8.1. Drying 862
27.8.2. Brining and marinating 862
27.9. Hazard analysis critical control point (HACCP) for ultrasound in food-processing operations 862
27.10. Conclusions and future trends 863
Chapter 28: Crystallization and freezing processes assisted by power ultrasound 870
28.1. Introduction 870
28.2. Fundamentals of crystallization 871
28.2.1. Saturation and supersaturation in solutions and melts 871
28.2.1.1. Saturation 871
28.2.1.2. Supersaturation 872
28.2.2. Nucleation 874
28.2.2.1. Primary nucleation 874
28.2.3. Growth 876
28.2.4. Induction time and metastable zone width 877
28.3. Impact of ultrasound on solute crystallization 877
28.3.1. Induction time 878
28.3.2. Polymorphism and crystallinity 879
28.3.3. Morphology and size distribution 880
28.3.4. Nucleation and growth rates 880
28.3.5. Agglomeration 881
28.4. Effect of ultrasound on ice crystallization (freezing) 882
28.5. Solute nucleation mechanisms induced by ultrasound 885
28.5.1. Thermodynamic (temperature and pressure) effect 886
28.5.2. Kinetic effect 887
28.5.2.1. Effect on the diffusion coefficient 887
28.5.2.2. Segregation 888
28.5.3. Chemical effect 889
28.5.4. Heterogeneous nucleation 890
28.6. Crystal growth and breakage mechanisms induced by ultrasound 890
28.7. Ice nucleation mechanisms induced by ultrasound 891
28.7.1. A general survey 891
28.7.2. A focus on the positive pressure effect 892
28.8. Future trends 895
Chapter 29: Ultrasonic drying for food preservation 900
29.1. Introduction 900
29.2. Ultrasonic mechanisms involved in transport phenomena 901
29.2.1. Convective transport 902
29.2.2. Diffusion transport 903
29.3. Ultrasonic devices for drying 904
29.3.1. Stepped-plate and cylindrical radiators 905
29.4. Testing the effectiveness of ultrasonic drying 908
29.4.1. Direct-contact applications 912
29.4.2. Airborne applications 915
29.5. Product properties affecting the effectiveness of ultrasonic drying 926
29.6. Structural changes caused by ultrasonic drying 930
29.7. Conclusions and future trends 932
Acknowledgment 932
Chapter 30: The use of ultrasonic atomization for encapsulation and other processes in food and pharmaceutical manufacturing 936
30.1. Introduction 936
30.2. Fundamentals of ultrasonic atomization 937
30.3. Ultrasonic atomizer design 941
30.4. Measuring droplet size and distribution 945
30.5. The effect of different operating parameters on droplet size 946
30.6. Applications of ultrasonic atomization in the food industry: encapsulation 949
30.7. Applications of ultrasonic atomization in the food industry: food hygiene 951
30.8. Applications of ultrasonic atomization in the pharmaceutical industry: aerosols for drug delivery 952
30.9. Applications of ultrasonic atomization in the pharmaceutical industry: encapsulation for drug delivery 954
30.10. Future trends 957
30.11. Conclusion 957
Part Five: Environmental and other applications 962
Chapter 31: The use of power ultrasound for water treatment 964
31.1. Introduction 964
31.2. Ultrasonic cavitation and advanced oxidative processes (AOPs) 964
31.2.1. Radical hydroxyl and AOPs 965
31.2.2. Sonochemistry of water: cavitation and hydroxyl radical 965
31.3. Sonochemical devices and experimentation 967
31.3.1. Sonochemical devices 967
31.3.2. Reactor calibration 968
31.3.3. Ultrasonic effectiveness for water treatment 968
31.3.4. Ultrasonic power and efficiency 970
31.4. Characteristics of sonochemical elimination 970
31.4.1. Oxidation of water soluble pollutants 970
31.4.2. Volatile organic molecules 972
31.4.3. Eliminating volatile and nonvolatile molecules from a mixture 972
31.5. Kinetic and sonochemical yields 975
31.5.1. Kinetic constant of the sonochemical reaction 975
31.5.2. Sonochemical yield and energy consumption 978
31.6. Sonochemical treatment parameters 978
31.6.1. The frequency effect 978
31.6.2. The influence of temperature 979
31.6.3. The influence of pH of the medium 980
31.6.4. The effect of dissolved gases 980
31.6.5. Formation of HNO2 and HNO3 in an aerated medium 981
31.6.6. Enhancers and inhibitors in ultrasonic treatment of natural water 982
31.7. Ultrasound in hybrid processes 982
31.7.1. Hydrogen peroxide as a driving force of the hybrid processes 982
31.7.2. Ultrasound and UV irradiation processes 984
31.7.3. Ultrasound action enhancement in Fenton and photo-Fenton processes 984
31.7.4. Ultrasound and ozone 985
31.7.5. Ultrasound and photocatalysis 987
31.8. Conclusion 988
Chapter 32: The use of power ultrasound for wastewater and biomass treatment 998
32.1. Introduction 998
32.2. Impact of ultrasound on biological suspensions 999
32.2.1. Examining bacterial biomass disintegration 1000
32.2.2. Sonication of bacterial biomass 1003
32.2.3. Activated sludge biomass 1004
32.2.4. Pure bacterial cultures: M. parvicella and P. aeruginosa 1005
32.3. Anaerobic digestion processes: full-scale application 1008
32.3.1. Enhancing anaerobic digestion: the Bamberg wastewater treatment plant (WWTP) 1010
32.3.2. Power ultrasound systems for biogas plants 1012
32.3.2.1. The Bordesholmerland biogas plant 1014
32.4. Aerobic biological processes: full-scale application 1015
32.4.1. Nitrogen removal 1015
32.4.1.1. The Bünde WWTP 1015
32.4.2. Combating filamentous bacteria and bulking sludge: the Seevetal WWTP 1016
32.5. Development and design of a full-scale ultrasound reactor 1017
32.6. Future trends 1019
Chapter 33: The use of power ultrasound for organic synthesis in green chemistry 1022
33.1. Introduction 1022
33.2. The green sonochemical approach for organic synthesis 1023
33.3. Solvent-free sonochemical protocols 1025
33.4. Heterogeneous catalysis in organic solvents and ionic liquids 1027
33.5. Heterocycle synthesis 1030
33.5.1. Reactions in water 1030
33.5.2. Solvent-free reactions 1033
33.5.3. Reactions in organic solvents 1034
33.6. Heterocycle functionalization 1036
33.6.1. Solvent-free reactions 1038
33.6.2. Reactions in organic solvents 1038
33.7. Cycloaddition reactions 1039
33.8. Organometallic reactions 1040
33.9. Multicomponent reactions 1042
33.9.1. Reactions in water 1042
33.9.2. Reactions in organic solvents 1043
33.10. Conclusions and future trends 1044
Chapter 34: Ultrasonic agglomeration and preconditioning of aerosol particles for environmental and other applications 1048
34.1. Introduction 1048
34.2. The development of practical applications of aerosol agglomeration 1049
34.3. Linear acoustic effects that determine the agglomeration process 1051
34.4. Nonlinear acoustic effects 1052
34.4.1. Radiation pressure and mutual radiation pressure 1052
34.4.2. Acoustic wake 1053
34.4.3. Acoustic streaming and turbulence 1054
34.5. Motion of aerosol particles in an acoustic field: vibration 1054
34.6. Translational motion of aerosol particles 1057
34.6.1. Translational motion due to radiation force 1057
34.6.2. Translational motion due to other effects 1057
34.7. Interactions between aerosol particles: orthokinetic effect (OE) 1058
34.8. Hydrodynamic mechanisms of particle interaction 1060
34.9. Mutual radiation pressure effect (MRPE) 1061
34.10. Acoustic wake effect (AWE) 1063
34.11. Modeling of acoustic agglomeration of aerosol particles 1067
34.11.1. Aerosol dynamics equation 1067
34.11.2. Acoustic agglomeration kernels 1067
34.12. Laboratory and pilot scale plants for industrial and environmental applications 1069
34.12.1. Development of acoustic agglomeration system for the removal of fine aerosol particles 1069
34.12.2. Experimental system for preconditioning fine aerosol particles 1071
34.12.3. Pilot scale acoustic preconditioning systems for coal combustion fumes and diesel exhaust aerosols 1073
34.13. Conclusions and future trends 1075
Chapter 35: The use of power ultrasound in mining 1084
35.1. Introduction 1084
35.2. The mining process 1085
35.3. Measuring the stress state in a rock mass 1085
35.3.1. The acoustic method for rock stress measurement 1086
35.3.2. Rock stress measurements using ultrasound 1087
35.3.3. Rock stress and ultrasonic propagation properties 1088
35.3.4. Rock stress measurements using power ultrasonic transducers 1089
35.4. Application of power ultrasound in mineral grinding 1094
35.4.1. Development of a high-pressure ultrasonic roll 1097
35.4.2. Characterizing the HPURM performance: Efficiency 1100
35.4.3. Characterizing the HPURM performance: Material wear testing 1101
35.4.4. Characterizing the HPURM performance: Rate of breakage tests 1102
35.5. Development of an ultrasonic-assisted flotation process for increasing the concentration of mined minerals 1104
35.5.1. The flotation process 1105
35.5.2. Power ultrasound in flotation 1107
35.5.3. Recent developments in the ultrasonic-assisted flotation process 1109
35.6. Conclusions and future trends 1115
Chapter 36: The use of power ultrasound in biofuel production, bioremediation, and other applications 1120
36.1. Introduction 1120
36.2. The chemical effects of ultrasound 1121
36.3. The molecular effects of ultrasound 1124
36.3.1. Physical changes 1125
36.3.2. Chemical changes 1126
36.3.3. Stress-induced changes 1127
36.4. Sonochemical reactors 1128
36.5. Biofuel production 1128
36.6. Ultrasound-assisted bioremediation 1131
36.6.1. Enzymes 1131
36.6.2. Effect of ultrasound on enzymes 1133
36.6.3. Enzymes as biocatalysts in bioremediation 1133
36.7. Biosensors 1136
36.8. Biosludge processing 1139
36.9. Conclusions and future trends 1142
Index 1148