iosr-JMCE   Volume-11 ~ Issue-4 ~ July-Aug 2014

Abstract: There are lot of plastic materials (PVC) being used in various applications and sometimes it requires knowing the life time of the products used in some critical application. These predictions of service life enable to understand and benchmark product life cycles in the application field. In the present project work we have studied the Thickness, Tensile Strength, Ply adhesion, Dimensional stability of PVC as a function of time with the constant exposure to the plastic product at 70°C for 24 week. The above mentioned properties were studied periodically as zero day sample or base property of the material. The regression analysis was conducted on the above test data and the prediction of the life span of the products was made as per ASTM.
Key Words: P VC, Flexible PVC Flooring, Dimension Stability, Tensile Strength, Ply Adhesion

[1]. Ivo Mersiowsky TUHH Technologies GmbH (TuTech), Integrated Management, Schellerdamm 4, D-21079 Hamburg, Germany, Polymer. Sci. 27 (2002) 2227–2277.
[2]. http://composite.about.com/od/Plastics/a/What-Is-Pvc-Plastics.htm.

[3]. https://law.resource.org/pub/in/bis/S03/is.3462.1986.
[4]. Garcia D, Balart R, Crespo JE, Lopez J. Mechanical properties of recycled PVC blends with styrenic polymers. J Appl Polymer Sci 2006; 101:2464e71.
[5]. Kaufman M. The history of PVC, the chemistry and industrial production of polyvinyl chloride. London: McLaren and Sons Ltd., 1969.

Abstract: Seat structures play a major role in the car passive safety. Due to their adjustment function mechanisms are generally involved in the seat failure mode. With the current evolution of automotive techniques, one of major automotive industry priorities is to decrease the product mass, design quicker and more efficient vehicles, emphasizing on travelling greater distances in short interval of time. For this comfort with safety of passengers is very important, thus the design of the seating system is very important. At the same time, seat rails have to fulfill high quality criteria, there are very strict requirements regarding strength and crash worthiness as the seat rail is regarded as a safety component it transfers forces from the driver / passenger to the car floor structure in case of a crash and they have to provide individual length adjustments possible. Amongst many parts, the seat tracks (upper and lower tracks) carry most of the load on seat structure considering human load. The aim of this project is to optimize an automotive seat track by reducing track thickness and its cost subjecting to static analysis. The adopted design has thickness of seat track as 1.5mm; scope of the present work involves Finite Element Modeling of Seat track assembly using HYPERMESH R 10. Pre-processing steps such as updating of element type, material properties, application of loads and Boundary condition is performed using HYPERMESH. The element type considered for the analysis is SHELL. Processing is carried using ANSYS. The results in the form of stress and displacement are extracted using HYPER VIEW.

Keywords: Seating System, Seat Track, Factor of Safety, Yield strength, Static Analysis, Von Mises Stress

[1]. Analysis and Optimization of Seat Rail assembly by Akbar Basha S, Surendra P.
[2]. Anti-submarine performance of an automotive seating system- A DoE study by Pavan Gupta. Vijay Ananda R Dhavanti Sindhe Jayant D Joshi Sreenivaasa Rao Nunna, K S Ramanath.
[3]. D. M. Severy, H. M Brink and J. D. Baird, "Collision Performance LM Safety Car", SAE No 670458, SAE Mid Year Meeting Chicago Illinois, (1967).
[4]. F W Babbs and B C Hilton. "The packaging of car Occupants – A British Approach to seat design", Chapter 32, Seventh STAPP car crash conference, (1967).
[5]. Prediction of failure on high strength steel in seat mechanisms simulation by M. Chauffray, G. Delattre, L. Guerin.
[6]. Challenges involved with developing seat slide assemblies using advanced high strength steels Tim Macnaughtan P.Eng.Dura Automotive Systems.

Abstract: Resource allocation problems in industrial processes have been widely studied. In this paper we present a case of maintenance technicians' allocation process simulation using cellular Automata and Voronoi diagram taking into account the spatial constraints. The aim is to extend the spectrum of constraints of the resource allocation problems and improve the previous works by carrying out the spatial dimension impact o performance optimization. To illustrate our approach some simulations are given.
Keywords: Cellular Automata, resource allocation, industrial, maintenance, Vornoi diagram

[1]. M. Bennour, D. Crestani, Using competencies in performance estimation: From the activity to the process, Computers in Industry 58 (2007) 151--163.
[2]. X. Boucher, E. Bonjour, B. Grabot, Formalization and use of competencies for industrial performance optimization: A survey, Computers in Industry 58 (2007) 98--117.
[3]. A-A. Alhouaij, Contribution à l'optimisation de la maintenance dans un contexte distribué, Ph.D. Thesis, Institut polytechnique, Grenoble, France, 2010.
[4]. C. Draghici, Modélisation et conception d'algorithmes pour la planification automatique du personnel de compagnies aériennes, Institut National de Sciences Appliquées, Toulouse, 2005.
[5]. L. Shi, C-H. Chen, A New Algorithm for Stochastic Discrete Resource Allocation Optimization. Discrete Event Dynamic Systems. Juillet 2000 , Volume 10 , Issue 3, pp 271-294

Abstract: The suspension of nanoparticles in fluids is called as nanofluids, it has been a subject of intense research these years due to their abnormal thermal characteristics. The enhanced thermal conductivity of these fluids with small-particle concentration was surprising. Micrometer-sized particle-fluid suspensions exhibit no such dramatic enhancement. This difference has led to studies of other modes of heat transfer and efforts to develop a comprehensive theory. Nanofluids are potential heat transfer fluids with enhanced thermophysical properties and heat transfer performance can be applied in many devices for better performances (i.e. energy, heat transfer and other performances). In this paper, a comprehensive literature on the thermal characteristics and applications of nanofluids in the thermal environment are compiled and reviewed.

Keywords: Nanofluids, Nanoparticles, Pool Boiling, Thermal Conductivity.

[1] Sarit Kumar Das., Stepen U.S. Choi., Hrishikesh E. Patel., Heat Transfer in Nanofluids— A Review Heat Transfer Engineering, 27(10):3–19, 2006 Copyright © Taylor and Francis Group, LLC ISSN: 0145-7632 print / 1521-0537 online, DOI: 10.1080/01457630600904593.

[2] Kim, P., Shi, L., Majumdar, A., and McEuen, P. L., Thermal Transport Measurements of Individual Multiwalled Nanotubes, Physical Review Letters, vol. 87, no. 21, pp. 215502–1–4, 2001.

[3] Shashi Jain., Hrishikesh E. Patel., Sarit Kumar Das., Brownian dynamic simulation for the prediction of effective thermal conductivity of nanofluid J Nanopart Res (2009) 11:767–773, DOI 10.1007/s11051-008-9454-4

[4] Gleiter, H., Nanocrystalline Materials, Progress in Materials Science, vol. 33, no. 4, pp. 223–315, 1989.

[5] Lee, S., Choi, S. U. S., Li, S., and Eastman, J. A., Measuring Thermal Conductivity of Fluids Containing Oxide Nanoparticles, Transactions of ASME, Journal of Heat Transfer, vol. 121,pp. 280–289, 1999.

Abstract: In this experimental study, attempts have been made to model and optimize EDM process parameters of die steel using different electrode shape namely, cylindrical, rectangular, and hexagonal shape based on Response Surface Methodology (RSM) by using statistical software, Design Expert (DX-6). Four independent input parameters, viz., pulse on time, pulse off time, peak current and tool shape were performed to explore the influence on material removal rate and overcut. The regression equation, and ANOVA was developed using the experimental data and graphs were plotted to investigate the effect of process variables on response characteristics. Multi response optimization was carried out using desirability function in conjunction with RSM to overcome the problem of contradictory responses of single response optimization. From the experimental data of RSM, empirical model were developed and the confirmation experiments were performed, which were found within 95% confidence interval. Optimal setting for multi response characteristics means for both MRR and Overcut are 33.84Amp IP, 10μs Ton, 5.10μs Toff, for the hexagonal shape of electrode. Keywords: Die steel, EDM, MRR, Overcut, RSM, Multi Response Optimization

[1]. Shankar Singh, Maheshwari, S., Pandey, P.C., 2004, "Some investigations into the electric discharge machining of hardened tool
steel using different electrode materials", Journal of materials processing technology 149, 272-277.
[2]. Hao Tong, Yong Li, and Yang Wang, "Experimental research on vibration assisted EDM of micro-structures with non-circular
cross-section", journal of materials processing technology 208 (2008) 289–298.
[3]. G. Skrabalak, J. Kozak, and M. Zybura, "Optimization of dry EDM milling process", Procedia CIRP 6 (2013) 332 – 337.
[4]. Sengottuvel. P, Satishkumar. S, and Dinakaran. D, "Optimization of Multiple Characteristics of EDM Parameters Based on
Desirability Approach and Fuzzy Modeling", Procedia Engineering 64 (2013) 1069 – 1078.
[5]. I.J. Mikesic, R.V. Fleisig, and P. Koshy, "Electrical discharge milling with oblong tools", International Journal of Machine Tools &
Manufacture 49 (2009) 149–155.

Abstract: In artificial intelligence, an expert system is a computer system that emulates the decision-making ability of a human expert. Expert systems are designed to solve complex problems by reasoning about knowledge, represented primarily as if–then rules rather than through conventional procedural code Robotics welding has been used over the years in some advanced countries like Japan, USA etc to weld but there has been series of problems encountered with the usage of these processes or method. These includes the difficulty of designing suitable software that will enhance robotic welding, the cost and skill required thereby creating a barrier to its usage. Welding operation is joining two metals together. The need arise for how to minimize or eliminate the error encountered when fatigue sets in, due to low efficiency of the local welder. CADD software for welding was developed using Microsoft visual studio package which was used to weld two mild steel plates together automatically, at the same time, it could be used for cylindrical hollow pipes. Therefore, this research work is based on reducing or eliminating such problems by creating a mean of designing a suitable and competent software that can aid robotic welding at a lower cost and above all which can be operated by anybody without the requirement of programming knowledge or any special skill. The result clearly shows that Robotic welding systems are able to operate continuously, provided appropriate maintenance procedures are adhered to. Continuous production line interruptions can be minimized with proper robotic system design. Robotic welding is faster, error free and uniformly welded all through like that of the CADD welding model developed.

Keywords: Computer Aided Design and Drafting, Robotic, Welding, Software, Expert System

[1] Cary, H.B.; Helzer, S.C. (1998) Modern Welding Technology, 6th ed.; Prentice Hall: Upper Saddle River, NJ, USA, pp. 1-2.

[2] Laplante, Phillip (2007). What Every Engineer Should Know about Software Engineering. Boca Raton: CRC

[3] Edward Hasted (2005). Software That Sells: A Practical Guide to Developing and Marketing Your Software Project.
[4] Gregory L. Snow and W. Samuel Easterling (2008) "Strength of Arc Spot Welds Made in Single and Multiple Steel Sheets", Proceedings of the 19th International Specialty Conference on Cold-Formed Steel Structures, Missouri University of Science and Technology, October 2008

[5] Maamar, R. H., Otmani, T. R., and Fahssi, N. D. D., (2008). Heat Treatment and Welding Effects on Mechanical Properties and Microstructure Evolution of 2024 and 7075 Aluminium Alloys. Centre de Recherche Scientifique et Technique en Soudage et Contrôle. Division de Mécanique et Métallurgie, Algeria. Vol. 5, pp. 13. – 15.

Abstract: Road Traffic has been growing with very rapid rate, hence the traffic intensity and volume on the road is high. The present road network is necessary to improve to accommodate the future traffic and to provide the good riding quality. The Parlakhemundi- Mohana road is proposed on cost analysis (basing on Cost- Benefit Ratio method), connecting two numbers state highway starting from parlakhemundi being its (intercept at 52/0 km of SH -4) and terminates at Mohana being its 102/9 km (intercept at 66/0km of SH-17) This road passes through the block head quarter of Rayagada, R.Udayagiri and Mohana connecting the district head quarter at Parlakhemundi. The total length of the road used for widening is up to 5kms length. The Traffic volume survey was also conducted on this road. The analysis of traffic volume data was done by projection up to 10 years. The need for widening of road from single lane to two lanes is justified as per the capacity of road. Based on the data collection toll fixation rates should be adopted for the improvement of the road in future. A method was adopted Cost- Benefit ratio method) which concludes that the road is economically viable for the proposed up gradation and improvements.

Index Terms: traffic intensity, single lane, double lane, cost-benefit ratio method, and up-gradation

[1] "Cost effective safety improvement for two lane rural roads" The discussion is with (Yinhai Wang gan&Atli Bjorn E. levy in TNW, Feb-2008)

[2] "Cost effective infrastructure measures on rural roads", has discussed that Jennifer Oxley, Bruce Corbin (ISBN, April, 2004, Report no.217, Page 157-165)

[3] "Cost effectiveness of lane and shoulder widening of rural, two lane roads", has discussed the following paragraph (Zenger,C.V.andMayes,J.G, in KBH, July1979Page no.8-72)

[4] "Study on Relation between CBR Value of Sub grade Soil and Moisture Content" The discussion is with Mehul l. Patel, Prof. N.G.Raval, Volume: I, Issue: X, July – 2012

[5] Laboratory studies on strength and bearing capacity of GSB-soil sub grade composites" is discussed by (Dr. Sureka Naagesh, Dr.R.Sathyamurthy, Sudhanva.S, IJIET, Vol.2, issue 2 April 2013)

Abstract: Problem statement: This study was made to increase productivity of separating process in many industries, to achieve the required aim, understanding the relationship between designed arithmetic methods on two and three coordinate planes to choose the parameters of the separating machine and computing additional factors including characteristics of materials and type of screen. Approach: The design of these types of separating machines did not include the addressed factors during the design; the study of these new factors will provide better understanding of the process and increase the abilities for improvement. Study made to define the right parameters of the operating surface, amplitude and vibration frequency that provide necessary productivity, efficient parameters of material. Results: The improvement included the machine design which consisted of screen; the screen design includes size, angle of inclination and taking into consideration the effect of the vibration trajectory. After applying primary data and the standard computation, the dynamic parameters are set and then the geometric parameters. According to the mathematical computation the design was made and then the verifying of the elements of speed of material motion. These mathematical equations can solve the problem of low productivity and high power consumption if implemented correctly and taking into consideration the dynamic and geometric elements of each case. Conclusion: The results of this study can be implemented in many fields of the industry where separation machine were used, the application of the mathematical relations can improve the revenue by increasing productivity and lowering power consumption for industry. For further study, the effect of wavy surface on the movement of particles will be advised. Keywords: Amplitude, Conveyor, Dynamic, frequency, Screen, Vibration.

[1] V.P. Franchuk, V.P. Naduty, and P.V. Levchenko, Increasing technological parameters bulk material by improving the dynamic schema, Proceedings of the National Technical University. Series: Chemistry, Chemical Engineering and Environment, 59 (965), 2012, 132-138.
[2] V.P. Franchuk, V.P. Naduty, and P.V. Levchenko, Determination of the trajectory of motion of the material, taking into account the transverse oscillations vibrating screen, Proceedings of the National Technical University. Series: Chemistry, Chemical Engineering and Environment, 57 (965), 2013, 142-148.
[3] J. S. Haddad, Basic Theoretical Backgrounds of the Engineering Design Procedure of a Drying Plant, American J. of Eng. and Applied Sciences 2(2), 2009, 466-470.
[4] F. Al-Quran, J. S. Haddad, M. Dweirj. Calculation Procedure to Choose the Design Parameters of Drying Machines, Springer, J. of Eng. Thermophysics, 4(18), 2009, 315-320.
[5] V.P. Naduty, P.V. Levchenko, Vibrating screen, Patent for useful model, 77403 UA, MPK8 B 07 B 1/40 (2006.01).National Academy of Sciences, Bull. 3, 11.02.2013, - 4.

Abstract: The paper proposes the use of Thermal Barrier Coating (TBC) materials in IC Engines to improve their thermal efficiency. Firstly, thermal analyses are investigated on two conventional (uncoated) single cylinder Petrol Engine models, made of Grey Cast Iron (GRADE ASTM 40) and aluminum silicon alloy. Secondly, thermal analyses are performed on two different specially designed petrol engine models, each of its combustion chambers being coated with two different Thermal Barrier Coating materials namely Perovskite Type Strontium Zirconate and Ruddlesden–Popper structured Barium Lanthanum Titanate BaLn2Ti3O10(BLT); by means of using a commercial code called ANSYS. Finally, the results obtained from all four thermal simulations are compared with each other. The effects of coatings on the efficiency of engines are investigated. Further investigations on these results reveal that there is a considerable reduction in heat loss through combustion chamber when TBCs are used. According to Otto cycle, for an ideal petrol engine the expansion process ought to take place under isentropic conditions (No heat transfer). Engines coated with TBCs restrict heat losses to a maximum extent thereby allowing expansion process to occur in near isentropic conditions. This in turn increases the net available energy. Therefore a raise in thermal efficiency of the engine can be achieved. 3(Associate Professor, Dept. of Mechanical Engineering, Panimalar Engineering College, India)

Keywords: Thermal Barrier Coatings (TBC), Perovskite Type Strontium Zirconate, Ruddlesden–Popper structured BaLn2Ti3O10 (BLT), Otto Cycle.

[1] D.R. Clarke and S.R. Phillpot, Thermal Barrier Coating Materials, Mater. Today, 2005.
[2] Z. Mišković, I. Bobić, S. Tripković, A. Rac, A. Vencl, The Structure and Mechanical Properties of an Aluminium A356 Alloy Base Composite With Al2O3 Particle Additions, Tribology in industry, Volume 28, No. 3&4, 2006.
[3] A.C. Alkidas, Performance and emissions achievements with an uncooled heavy duty, single cylinder diesel engine, SAE, vol. 890141, 1989.
[4] Xizhong Wang, Lei Guo, HongboGuo, Guohui Ma, Shengkai Gong, Effects of Pressure during Preparation on the Grain Orientation of Ruddlesden-Popper Structured BaLa2Ti3O10 Ceramic, Journal of Materials Science & Technology 01/2013.
[5] Hieu Nguyen, Manufacturing Processes and Engineering Materials Used in Automotive Engine Blocks, April 8, 2005.
[6] Lei Guo, HongboGuo, Guohui Ma, Musharaf Abbas, Shengkai Gong, Ruddlesden–Popper structured BaLa2Ti3O10, a highly anisotropic material for thermal barrier coatings, 2012 | 38 | 5 | 4345-4352.

Abstract: The paper provides a brief overview of the research areas of heavy machinery through maintenance models. It is not meant to be a complete review of maintenance models but rather as an informative introduction to important maintenance models. The paper is concerned with the basic preventive maintenance policies arising in the context of heavy machinery maintenance. The investigation in this paper relates mainly to develop preventive replacement model and fault tree analysis for the horizontal boring machine and to reduce the down-time of the machine. Simple but practically important preventive maintenance optimization models, which involve age replacement and block replacement, are reviewed in the framework of the expert maintenance policy. The study was carried out in a mechanical workshop of an engineering construction company in a private sector. There are different machines and hand tools such as Bending machine, CNC Profile cutting machine, vertical turning and boring, horizontal turning and Boring, Gear hobbling machine, Lathe machine, Milling Machine, Plano miller, Planner machine, Grinding Machine, Press, Shearing Machine, hammers and area repair shops equipments. Since the concern was on machining of construction equipment so the study was concentrated on Horizontal & Vertical Turing and Boring.

Keywords: Expert system, Fault Tree Analysis, Markov Model, MTBF, MTTR, Preventive Maintenance

[1] Adhammar Et.al, Preventive Management/Essential care Condition monitoring

[2] D.W.Rolston, Principles of Artificial Intelligence and Expert Systems Development, McGraw-Hill, 1988

[3] Jardine AKS, Maintenance, Replacement & Reliability, Pitman Publication

[4] Jim Parentzas, A Wab- Based controlled By a Hybrid expert System.

[5] L.S.Srinath, Reliability Engineering Affiliated East-West Press Private Limited New Delhi.

[6] Md. Ben-Daya, Salih O. Dufffuaa, Abdul Raouf Maintenance, Modeling& Optimization

Abstract: The aim of this paper is to study evolution of precipitation during aging at different temperatures in cast aluminium alloy-354 grade. Scanning electron microscope (SEM) is used to examine these precipitates. Purpose of applying this technique of microscopic analysis was mainly to investigate the distribution, size and density of hardening precipitates as a function of aging temperature. The heat treatment of alloy comprises of, Solutionizing, quenching and aging. Tensile testing is carried out after aging at different temperatures and the resulting fractured piece is used for microscope analysis. The SEM images are used to compare precipitation at different aging temperatures. Tensile test results are generated after aging at different temperatures. The mechanical properties of the material are correlated with microstructure.

Key Words: Scanning Electron Microscope (SEM), Cast Alloy Al-354, Precipitate Distribution, Aging Treatment.

[1]. H.R. Ammar, A.M. Samuel, F.H. Samuel, E.Simielli,G.K. Sigworth ,J .C. Lin: "Influence Of Aging Parameters On The Tensile Properties And Quality Index Of Al-9 Pct Si-1.8 Pct Cu-0.5 Pct Mg 354-Type Casting Alloys" The Minerals , Metals & Materials Society And ASM INTERNATIONAL 2011 DOI: 10.1007/S11661-011-0808-7.
[2]. R.C.Lemon And C.R.Hewie,AFS Trans.,1963,Vol .70, Pp.465-70.
[3]. J.G.Kaufman And E.L.Rooy: Aluminium Alloys "Castings,Properties,Processingand Applications", ASM INTERNATIONAL, Materials Park, OH, 2004, Pp, 31-32 & 69-131.
[4]. X.Q.Jhao,M.J.Shi,J.H.Chen, S.B Wang, C.H.Liu, C.L.Wu: "A Facile Electron Microscopy Method For Measuring Precipitate Volume Fraction In Al Cu Mg Alloys" ELSEVIER Inc 2002.DOI: 10.1016/J.Matchar.2012.04.009.
[5]. N.Chomsaeng,M.Haruta, Chairuangsri,H.Kurata, S.Isoda, M.Shiojiri :"H R TEM And ADF-STEM Of Precipitates At Peak-Ageing In Cast A365 Aluminium Alloy". ELSEVIER 2010 Inc DOI: 10.1016/J.Jallcom.2010.02.084.

Abstract: The objective of this paper is to deliver a predispose about an automated & system integrated machine named as 'Cot Chamfering Machine' with the help of the data obtained by thorough research and development techniques. The subsequent machine contributes to the precise delivery of sophisticated chamfering operation performed on a part named 'Rubber Cot', which is primarily used in textile industries. This prescriptive paper offers genuine concepts & overview of the research and development done on the respective machine along with the basic introduction about the same. The machine has the huge scope for development as it is being an automated & system integrated machine and the same has been portrayed in the following paper.

Keywords: Automation & System Integrated Machines, Chamfering, Rubber Cot, Special Purpose Machine

[1]. T. R. Jawanjal, S. T. Bagdem, 'An Advanced Chamfering System' International Journal of Emerging Technology and Advanced Engineering, Volume 3, Issue 2, February 2013.
[2]. Keith Stouffer, Fred Proctor, Elena Messina, 'An Advanced Deburring And Chamfering System (ADACS) Based On The Enhanced Machine Controller', National Institute Of Standards And Technology, Gaithersburg, Maryland.
[3]. SangramKotkar, Dr. R. J. Patil, 'Review on Chamfering Machine Operations', International Journal of Engineering Research & Technology, Vol. 3, Issue 6, June 2014.
[4]. H. Kazerooni, J.J. Bausch, B.M. Kramer, 'An approach to Automated Deburring By Robot Manipulators', Journal of dynamic system measurement, and control, vol 108 - 1986.
[5]. Frederick Proctor, 'Controls And Sensors For Advanced Manufacturing', National Institute Of Standards And Technology, Gaithersburg, Maryland.

Abstract: Air coupled ultrasonic Non -destructive inspection (NDI) is considered a viable option to the Ultrasonic water jet based systems which are currently used to check the composite structures. Present research paper demonstrates experimental method of inspection E-glass composite laminate using ultrasonic guided wave technique using air coupled transducers.

Keywords: Composite structures, guided waves, air coupled transducers, Ultrasonics, NDI.

[1] N. Hariharan, K. Balasubramaniam, and A. C. Bose, "INCREASE IN EFFICIENCY OF AIR-COUPLED L-SCAN ( LAMB WAVE SCAN )," 2011.

[2] P. Belanger, "FEASIBILITY OF THICKNESS MAPPING," 2009.

[3] B. Harris, "ENGINEERING COMPOSIT MATERIALS," 1999.

[4] J. Peters, V. Kommareddy, Z. Liu, D. Fei, and D. Hsu, "NON-CONTACT INSPECTION OF COMPOSITES USING AIR-COUPLED ULTRASOUND," vol. 22, pp. 973–980, 2003.

[5] B. B. Djordjevic and G. Burnie, "NONDESTRUCTIVE TEST TECHNOLOGY FOR THE COMPOSITES Keynote lecture," pp. 259–265, 2009.

[6] E. C. Cv and A. L. U. K. Tel, "NEW DESIGNS OF FOCUSSED AIR-COUPLED ULTRASONIC TRANSDUCER."