The nonlinear model of the electro-valve driven hydraulic system is presented. Base on mathematical model, a speed control of an electro-hydraulic system is investigated in the paper based on Dynamic Surface Control (DSC). DSC is a systematic controller caculated by combining backstep-ping technique and sliding mode control... In order to regulate the system's state to the desired speed under the changes of external torque, an adaptive control is proposed in this paper. The system stability is proven, and a number of simulations are given to illustrate the effectiveness of the controller.

Keywords: Hydraulic system, Dynamic surface control, Adative control, Backstepping-sliding mode control, Lyapunov's stability

[1] M. B. Rannow and P. Y. Li, "On/off valve based position control of a hydraulic cylinder," in ASME 2007 International Mechanical Engineering Congress and Exposition, 2007, pp. 141–149.

[2] A. A. Aly, "Model reference PID control of an electro-hydraulic drive," Int. J. Intell. Syst. Appl., vol. 4, no. 11, p. 24, 2012.

[3] D. Lovrec, V. Tic, and T. Tasner, "Simulation-aided determination of an efficiency field as a basis for maximum efficiency controller design," Int. J. Simul. Model., vol. 14, no. 4, pp. 669–682, 2015.

[4] F. Najafi, M. Fathi, and M. Saadat, "Dynamic modelling of servo pneumatic actuators with cushioning," Int. J. Adv. Manuf. Technol., vol. 42, no. 7–8, pp. 757–765, 2009.

[5] C. C. Soon, R. Ghazali, H. I. Jaafar, S. Y. S. Hussien, S. M. Rozali, and M. Z. A. Rashid, "Position tracking optimization for an electro-hydraulic actuator system," J. Telecommun. Electron. Comput. Eng., vol. 8, no. 7, pp. 1–6, 2016.

The objective of The ability to harvest energy from the environment represents an important technology area that promises to eliminate wires and battery maintenance for many important applications and permits deploying self powered devices. This paper suggests the Application of Charging Mobile Phone by solar energy. In the beginning, a comprehensive overview to the energy harvesting concept and technologies is presented. Then the Application of Charging Mobile Phone by solar energy its efficiency to charge the aimed batteries under sunlight or an indoor artificial light. However it becomes very inconvenient for persons occupied with work or travelling long distances as the average lifetime of a mobile phone battery is less than 10 hours.Solar phone chargers use small solar panel to absorb light. This process still forces customers to carry another device along with their cell phone.

Keywords: mobile phone , battery , sun , solar energy

[1]. http://www.esdalcollege.nl/eos/vakken/na/zonnecel.htm
[2]. Dinesh .Amira .M. Achuthan, " SOLAR POWER OPERATED TABLE FOR CHARGING ELECTRONIC GADGETS " , international Journal of Students' Research In Technology & Management ISSN 2321-2543, Vol 5, No 3, September 2017, pp 11-15 .
[3]. Y. Kim, Y. W.Chang and M. Pedram,"Maximum power Transfer tracking in a solar charger for smartphones". Int.J.in Advent Technology. Vol.1.pp.1-5,2015.
[4]. K. U. Chafle, B. M.Faruk, R. S.Shrivas and N.S. Sawarkar, "Coin based mobile charger on solar energy". Int.J.of Reserch –Granthaalayah, vol.3,pp. 13-18, 2015.
[5]. Y. Liu, Z. Qin and C. Zhao, "AutoCharge: Automatically Charge Smartphones Using a Light Beam". Int.J. Microsoft Research. vol. 1. pp.1-12,2015.

Search provided is Empirical Study of Multi-roundabout object in Benghazi Libya claims ALSALAM roundabout and it is one of the largest courses in the city of Benghazi, because of its importance you examine the situation of congestion worsening because of the traffic around the roundabout, which requires knowledge of the characters of this congestion and know all the reasons. It is contains an introduction to include on the background of the subject matter described the details of the study site and also the population of the city of Benghazi as there are details of the study area and its environs and to clarify the problem statement and objectives of the study, which aims to develop a solution to this problem and finally contains a flow chart of the search. This chapter includes the theories of text analysis of traffic flow around the roundabout and also on the traffic analysis equations Following the Indonesian Code (IHCM) where there is utmost account transactions, including the rotor conclude degree of saturation of the roundabout compared to the traffic flow with the traffic capacity...........

Keywords: component, formatting, style, styling, insert (key words)

[1]. Federal Highway Administration (FHWA). Manual on Uniform Traffic Control Devices. Washington, D.C.: FHWA, 1988.
[2]. Department of Transport (United Kingdom). Geometric Design of Roundabouts. TD 16/93. September 1993.
[3]. Transportation Research Board. Highway Capacity Manual.Special Report 209. Washington, D.C.: Transportation Research Board, National Research Council, July 1999 (draft).
[4]. Courage, K.G. "Roundabout Modeling in CORSIM." Presented at the Third International Symposium on Intersections without Traffic Signals, Portland, Oregon,U.S.A., 1997.
[5]. Paramics, Ltd. "Comparison of Arcady and Paramics for Roundabout Flows." Version 0.3. August 23, 1996.

In this paper, using the concept of F - contraction, we first establish a unique common fixed point theorem for two self mapping on complete b-metric spaces. The results extend and generalize some results in the literature.

Keywords: Complete b- metric space, common fixed points, F-contractions.

[1]. Ahmad et al. Fixed Point Theory and Application (2015) 2015:80.
[2]. H.H. Alsulami, E. Karapinar, H. Piri, Fixed points of generalised F-Suxuki type contraction incomplete b-metric spaces, Discrete Dynamics in Nature and Society, 2015, 8 pages.
[3]. H. Aydi, M.F. Bota, E. Karapinar, S. Mitrovic, A fixed point theorem for set-valued quasi-contractions in b-metric spaces, Fixed Point Theory Appl., 88(2012), 8 pages.
[4]. H. Aydi, M.F. Bota, E. Karapinar, S. Moradi, A common fixed point for weak ϕ-contractions on b-metric spaces, Fixed Point Theory, 13(2012), no. 2, 337-346.
[5]. S. Banach, Sur les operations dans les ensemble abstraits et leur application aux equations integrales, Fundamental Mathematicae 3(1922) 133-181.

Structural systems like plan asymmetry is mostly seen in modern multi-storey constructions in urban areas. In the present study, the behavior of G+5 storied reinforced concrete frame buildings having irregularities confirming to IS 1893 (Part 1), 2016 subjected to an earthquake such as, re-entrant corner and diaphragm discontinuity located in seismic zone V is analyzed under non-static response pushover analysis using SAP2000 v21 software. The main objective of the study is to carry out the performance-based analysis-pushover analysis to obtain performance levels of asymmetric buildings for the future earthquakes and to understand different irregularity. Different types of model such as R1, R2 for re-entrant corner and D1, D2 for diaphragm discontinuity analyzed in the study. The various parameters like capacity spectrum curve, performance point and roof displacement of different models are considered for comparison. It is observed that the model with diaphragm discontinuity has more load carrying capacity than the model with re-entrant corner. Further it is observed that asymmetric model has different displacement value in both direction while in symmetric model, displacement values are same.

Keywords: Diaphragm discontinuity, Load carrying capacity, Pushover analysis, Re-entrant corner.

[1]. Modakwar, N. P., Meshram, S. S., & Gawatre, D. W. (2014). Seismic Analysis of Structures with Irregularities. IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE), 4 (63-66).
[2]. G. M., Shetty, K. K., & Hegde, A. K. (2014). Non Linear Static Pushover Analysis of Irregular Space Frame Structure With And Without T Shaped Columns. International Journal of Research in Engineering and Technology, 663-667.
[3]. Ahmed, J., & Raza, S. A. (2014). Seismic Vulnerability of Rc Buildings by Considering Plan. Global Journal For Research Analysis, 6 (42-47).
[4]. Siva Naveen.E, Nimmy Mariam Abraham and Anitha Kumari S.D (2018) "Analysis of Irregular Structures under Earthquake Loads", 2nd International Conference on Structural Integrity and Exhibition 2018, ELSEVIER.
[5]. ATC-40 - "Seismic Evaluation and Retrofit of Concrete Buildings", Applied Technology Council, November 1996..

Conventional seismic design attempts to make buildings that do not collapse under strong earthquake shaking, but may sustain damage to non-structural elements and to some structural members in the building. This may render the building non-functional after the earthquake, which is not acceptable for important buildings, like hospitals, fire stations, etc. Special techniques are required to design buildings they remain practically undamaged even in a severe earthquake. Buildings with such improved seismic performance usually cost more than normal buildings. However, this cost is justified through improved earthquake performance. One of the technologies used to protect buildings from damaging earthquake effects is ―Base Isolation‖. The idea behind base isolation is to separate (isolate) the building from the ground in such a way that earthquake motions are not transmitted up through the building, or at least greatly reduced............

Keywords: earthquake force, confined displacement, control collapse of building, safety of building

[1]. Farzad Naeim, Ronald L Mayes (2000), ―Design of Structures with Seismic Isolation‖, Seismic Design Handbook, Chapter 14, pg.723-756
[2]. Yeong-Bin Yang, Kuo-Chun Chang, Jong-Dar Yau (2000), ―Base Isolation‖, Earthquake Engineering Handbook, Chapter 17, pg.17.1-17.31
[3]. Rihui Zhang (2000), ―Seismic Isolation and supplemental Energy Dissipation‖, Bridge Engineering - Seismic Design, Chapter 9, pg 9.1-9.36
[4]. David Key (1998), ―Isolation and Energy Absorbers‖, Earthquake Design Practice for Buildings, Chapter 4, pg. 69-79
[5]. Chopra A. K. (2001), ―Base Isolation‖, Dynamics of Structures - Theory and Applications to Earthquake Engineering, Pearson Education, 2nd Edition, 2001.

Classification of objects is a basic task carried out for nearly every product. A common classification method is by classifying an object based on its shape and/or size. By scanning any object, one can look for intricacies in its design. This poses a need for a simple and efficient solution for scanning an object for its 3 dimensional structure. 3 dimensional modeling has become quite popular in recent times and various research is happening in the field of 3 dimensional scanning. Our project aims at bringing the same features and convenience when it comes to detecting and manipulating 3 dimensional objects. It allows the user to understand various structures and replicate them on a computer to understand the mechanics behind the structure..........

Keywords: 3 Dimensional modelling and scanning, Photogrammetry principle, Reconstruction.

[1]. https://www.emerald.com/insight/content/doi/10.1108/LHT-10-2017-0206/full/html?af=R Henson, K., Constantino, P., O'Keefe, F. and Popovich, G. (2019), "Three-dimensional scanning and printing techniques to analyze and archive human skeletal remains", Library Hi Tech, Vol. 37 No. 3, pp. 389-400. https://doi.org/10.1108/LHT-10-2017-0206
[2]. https://en.wikipedia.org/wiki/Photogrammetry
Wikipedia contributors. (2020, April 14). Photogrammetry. In Wikipedia, The Free Encyclopedia. Retrieved 17:05, April 28, 2020.
[3]. http://students.iitk.ac.in/eclub/assets/documentations/summer14/3d_laser_scanner.pdf
This was a research paper published by iitKanpur students where they had explained about entire process of 3-d scanning , its various types, comparison between them and explained various aspects of laser scanning.
[4]. https://www.kickstarter.com/projects/621838643/desktop-3d-scanner
CADScan was formed in 2011, motivated by a desire to make 3D scanning easy to use and accessible to all. They developed a system software using their prototype scanner hardware on their own simulation software. A complete system simulation is created which allows them to test and validate system performance and to optimize the configuration of the scanner for several different applications [7].

The tradition of treating sewage in India is not very popular and the practice which is in use is direct discharge in various natural water bodies. Where ever the sewage is treated the main problem occur is dumping of sludge, as it dumped in an open environment which leads to pollution in environment. On other hand, brick is one of the important element in civil engineering and construction industry, so using sludge as primary brick manufacturing material will make the brick more economical as well as load of sludge for dumping will automatically get reduce. The work of using sludge as a brick manufacturing material is in progress all around the globe and India is also making a remarkable progress in this direction. We are trying to use sludge in various proportions with fly ash and with clay after performing all tests we will analyze the feasibility of sludge as brick manufacturing material.

Keywords: Sludge, Sewage, STP-Sewage Treatment Plant, Sludge Disposal, Clay, Brick

[1]. P.Amsayazhi1, K.Saravana Raja Mohan,Use of Sludge Waste as Ingredient in Making of Brick,International Journal of Engineering &Technology, 7 (3.12) (2018) 419-422
[2]. Keerthana. S, Kavya. K, Pradeep.T, Sharmila.S, Study on Effect of Partial Replacement of Sludge in Bricks, International Journal of Recent Technology and Engineering (IJRTE) ISSN: 2277-3878, Volume-7, Issue-6, March 2019
[3]. Ponkarthikeyan P, Ganesh R, Sheerin Farzana A, Experimental Study on Bricks Using Water Treatment Sludge, International Journal for Research in Applied Science & EngineeringTechnology (IJRASET), Volume 4 Issue XI, November 2016, IC Value: 13.98 ISSN: 2321-9653
[4]. Govind Bikkad, Chetan Sontakke, Baliram Janwade, Gajendra Giri, Vaibhav Kalbhor, Rohini Khandelwal, Replacing The Fly Ash By Stp Dry Sludge In Manufacturing Of Fly Ash Bricks, International Research Journal of Engineering and Technology (IRJET), Volume: 05 Issue: 06 | June 2018
[5]. Yousif Algamal, N. M. Khalil1, Qayid M. Saleem, Usage of The Sludge From Water Treatment Plant
In Brick-Making Industry, Journal of Chemical Technology and Metallurgy, 53, 3, 2018, 504-510

Ensemble methods is a strategy based algorithm. It is the combination of best suited machine learning algorithms to get more reliable, accruable result, ensemble methods came in to picture. Troupes (ensemble) are sets of learning machines that consolidate their choices or their learning calculations, or different perspectives on information, or other specific attributes to acquire increasingly solid and progressively precise expectations in regulated and also learning issues. In this paper the previous study related to Ensemble methods is discussed and gives a future aspect of Ensemble methods. Here also discussed about the categorization of Ensemble methods, As well as the comparison between single machine learning model and combination of multiple models is given. These days outfit strategies speak to one of the fundamental momentum research lines in Artificial Intelligence. The main purpose of this study is to spread out the importance of Ensemble Methods and prediction of future aspect of it.

Keywords: Ensemble Methods, Combination of classifiers

[1]. Alejandro Pena-Ayala, Educational data mining: A survey and a data mining-based analysis of recent works, Expert Systems with Applications, Pp.1432-1462,(2014).
[2]. C.Romeroand S.Ventura. Educational Data Mining: A Survey from 1995 to 2005. Expert Systems with Applications,Vol.33,(2007),135-146.
[3]. Han, J., Kamber, M., and Pei, J. (2013). Data Mining Concepts and Techniques, third edition. Morgan Kaufmann.
[4]. Hashmia Hamsa, Simi Indiradevi, Jubilant J.Kizhakkethottam. Student academic performance Prediction Model Using Decision Tree and Fuzzy genetic algorithm, Procedia Technology, Vol. 25 (2016), 326 332.
[5]. Evandro B. Costa *, Baldoino Fonseca, Marcelo Almeida Santana, Fabrsia Ferreira de Arajo, Joilson Rego., Evaluating the effectiveness of educational data mining techniques for early prediction of students‟ academic failure in introductory programming courses, Computers in Human Behavior 73 (2017) 247-256.

With the rapid expansion of economic production and urban areas, the climate becomes abnormal and the original water circulation disturbed or totally destroyed, which makes the settlements and communities suffer from water related threats such as drought, flood and water logging. The water management strategies in the heritage landscape concerned are in line with landscape ecological requirements, and the need for sustainable development through practice and the test of time. Vernacular architecture, as part of the landscape heritage, has a deep root in tradition, being a cultural asset which influences the traditional and sustainable land use through the location, form, material, structure and size of the buildings. The classical courtyard house of China, the "YuanLuo", represents an outstanding............

Keywords: landscape heritage; water management; sustainable landscape; Shang Gan Tang village, cultural landscape

[1]. Biesbroek, G. R., Swart, R. J., Carter, T. R., Cowan, C., Henrichs, T., Mela, H., Rey, D. (2010) Europe adapts to climate change: Comparing National Adaptation Strategies. Global Environmental Change, 20(3), 440–450. https://doi.org/10.1016/j.gloenvcha.2010.03.005
[2]. Bougdah, H. (2017) The Courtyard House: Can a Sustainable Future Learn from a Context Relevant Past International Journal on: Environmental Science and Sustainable Development, pp. 83-95DOI: 10.21625/essd.v1i1.17ISSN (Print: 2357-0849, online: 2357-0857)
[3]. Carter, R. C., Tyrrel, S. F., & Howsam, P. (1999) The impact and sustainability of community water supply and sanitation programmes in developing countries. Water and Environment Journal, 13(4), 292–296. https://doi.org/10.1111/j.1747-6593.1999.tb01050.x
[4]. Casey, A., & Becker, A. (2019) Institutional and Conceptual Barriers to Climate Change Adaptation for Coastal Cultural Heritage. Coastal Management, 47(2), 169–188. https://doi.org/10.1080/08920753.2019.1564952
[5]. Crouch, D. P. (1990) Planning water management for an ancient Greek city. In Hydrological processes and water management in urban areas. Lectures and papers, UNESCO/IHP symposium, Duisburg, Lelystad, Amsterdam, and Rotterdam, 1988.

Behavior of horizontal well in edge-water drive reservoirs at late time is the objective of this study and this was carried out by developing a model using source function and Newman product rule. Numerical method was used to compute dimensionless pressure and dimensionless pressure derivative. From the results we can see that PD became constant from tD =10 to tD =10000.This is an indication showing that the flow has encountered boundary, while P'D has some negativity values. This shows that there is water production due to excess water from edge water support. A clean oil can be produced between when 1 ≥ tD ≥0. 001.Effect of some parameters were considered. The height of a well has a significant role in the oil production in horizontal well. The higher the value of hD more oil will be produced. Hence during well completion the height should be considered for optimal production.

[1]. G. Eason, B. Noble, and I.N. Sneddon, "On certain integrals of Lipschitz-Hankel type involving products of Bessel functions," Phil. Trans. Roy. Soc. London, , April 1955, vol. A247, pp.529-551
[2]. J. Clerk Maxwell, A Treatise on Electricity and Magnetism, 3rd ed., vol. 2. Oxford: Clarendon, 1892, pp.68-73.
[3]. I.S. Jacobs and C.P. Bean, "Fine particles, thin films and exchange anisotropy," in Magnetism, vol. III, G.T. Rado and H. Suhl, Eds. New York: Academic, 1963, pp.271-350.
[4]. K. Elissa, "Title of paper if known," unpublished.
[5]. R. Nicole, "Title of paper with only first word capitalized," J. Name Stand. Abbrev., in press.
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The present communication deals the structural behaviour of Sodium Hexane Sulphonate (SHS) in water and in aqueous alanine solutions at 303ºK in terms of classical absorption, relaxation frequency, relaxation time and relaxation strength.

Keywords: Ultrasonic, SHS, Aqueous Alanine Solution

[1]. Tadros, Th. F. The surfactants, Academic Press, London, 1984.
[2]. Singh, S.P., Saigal, M. and Singh, A., "Characteristics of N+-DTT in Water and Aqueous Maltose Solutions at 303K"J. Biol. Chem. Research. 2019; 36(1), 198.
[3]. Singh, S.P., Soni, A.K. and Saigal, M., "Ultrasonic Studies of C10 DTTDTT in Water and Aqueous Maltose Solutions at 303K" IJRASET, 2019: 7(V), 3682.
[4]. Linfield, W. and Linfield, M. Anionic surfactants. Marcel Dekker, W.M. (ed.). New York, 1967.
[5]. Lucassen, E.H. and R. Eynders : Surfactants, Marcel Dekker, New York, 1981.

A nozzle is a tube of varying cross-sectional area aiming at increasing the speed of an outflow, and controlling its direction and shape to produce thrust which is the result of pressure which is exerted on the wall of the combustion chamber. For this design selected lunching condition,Ethiopia, around Ambo city. approximately 6,893 feet above sea level and atmospheric pressure is around 1.012 bar. this paper used mathematical method like interpolation, extrapolation and iteration in the precision of 10-5 todefine design parametersand also select the material from different perspective like nozzle erosion and thermal-stress cracking. finally reach on the conclusion that an expansion ratio (AeA) of 8 and throat area, the contact point of Xn2 = (0.01207, 0.04254 ^ 0.01207, - 0.04254) with small circle also the two circles contact point on Xn1 = (0, 0.035 ^ 0, - 0.035).

Keyword: Nozzle, Thrust, Solid propellant, Expansion ratio, Mach number

[1]. http://webserver.dmt.upm.es/~isidoro/bk3/c17/Nozzles.pdf [2]. https://www.narom.no/undervisningsressurser/sarepta/rocket-theory/rocket-propellants-2/solid-propellants/
[3]. https://www.sciencedirect.com/science/article/pii/S2352146518300279
[4]. http://maenas.eng.usu.edu/MAE_5540_Web/propulsion_systems/subpages/Rocket_Propulsion_Elements.pdf
[5]. https://www.researchgate.net/publication/328086005_Design_of_Nozzle_for_High Powered_Solid_Rocket_Propellant/fulltext/5bb6cabe4585159e8d8686a6/328086005_Design_ofNozzle_for_High-Powered_Solid_Rocket_Propellant.pdf?origin=publication_detail

The extraction of lemongrass oil was performed with Soxhlet extractor apparatus using ethanol as solvents. The extraction was carried out with lemongrass sample with particle size 0.5cm, 1.0cm, 1.5cm, 2.0cm and 2.5cm and the respective oil yields were noted.The characterization of the oil sample was donewith Fourier's Transformed-Infrared Spectroscopy (FTIR) and Gas Chromatography-Flame Ionization Detector (GC-FID) analytical techniques. The FTIR result showed ten (10) functional groups that include halo-compound, alkene, alkane, sulphate, aldehyde, thiol,isothiocyanate, carboxylic acid, alcohol, and aromatic compound. Furthermore, the GC-FID analyses indicated the occurrence of nineteen (19) different components in the lemongrass extract which includeα-pinene (12.9%), 2-nonanone(10.3%), acetonitrile(7.5%), β-cedrenes(6.6%), camphor(6.4%), citronellal(6.0%), 4-nonanone(5.9%), terpinolene(5.4%), decanal(5.3%), α-cedrol(5.3%), citral A(5.0%), β-pineane(4.4%), atlantone(3.6%), pentane(3.3%), p-cymene(3.1%), γ-terpinene(2.8%), α-cedrenes(2.6%), thujopsene(2.0%) and genaniol(1.7%). In this research work, the highest constituent obtained was α-pinene making up of 12.9% of the oil sample and the citral content was 5.0%. Itis concluded that lemongrass oil is made up of different bioactive chemicals which sometimes varies according to geographical origin, biodiversityand culture.

Keywords: Essential Oil, Ethanol, Lemongrass, Modelling, Physicochemical, Soxhlet Extraction

[1]. Adams, R.P. (2001). Identification of essential oil components by gas chromatography/ quadrupole mass spectroscopy. 3rd ed., Allured pub. Co. Carol stream, Illinois, USA.
[2]. Adams, R.P. (2007). Identification of essential oil components by gas chromatography/mass spectrometry. 4th ed., Allured Publishing Corporation. Carol Stream, Illinois USA.
[3]. Anaruma, N.D., Schmidt, F.L., Duarte, M.C, Figueira, G.M. Delarmelina, C., Benato, E.A. and Sartoratto, A. (2010). Control of Colletotrichumgloeosporioides(Penz.) Sacc. in yellow passion fruit using Cymbopogon citratus essential oil. Brazilian Journal of Microbiology ,41:66–73. doi:10.1590/S1517-83822010000100012
[4]. Ashgari, J., Touli, C.K., and Mazaheritehrani, M. (2010). Microwave-assisted hydrodistillation of essential oils from Echinophoraplatyloba DC. Journal of Medicinal Plants Research, 6(28):4475-4480.
[5]. Bleasel, N., Tate, B. and Rademaker, M. (2002). Allergic contact dermatitis following exposure to essential oils. Australas. J.Dermatol. 43(3): 211–3. doi:10.1046/j.1440-0960.2002.00598.x.

There are many ways to use ultrasound Lamb waves for damage imaging. Among them, ultrasonic phased array imaging has attracted wide attention in the field of ultrasonic imaging due to its advantages of good flexibility, high detection efficiency and high imaging accuracy. Among the existing ultrasonic phased array imaging methods, a more widely used method is an algorithm for delay superimposing time-domain signals with fixed weight values. Although this method has high imaging efficiency, it can not effectively suppress the noise of non-scanning azimuth, so side lobe artifacts will occur and the imaging resolution is not high. There are other damage detection methods such as time reversal and ellipse positioning, but these methods cannot achieve super-resolution imaging of damage because they cannot break through the Rayleigh limit.Therefore, based on the ultrasound Lamb wave phased......

Keywords: nondestructive testing, ultrasonic phased array, multiple signalclassification, super resolution.

[1]. Devaney, Anthony J. Mathematical Foundations of Imaging, Tomography and Wavefield Inversion[J]. 2012.
[2]. Gruber F, Marengo E and Devaney A. Time-reversal imaging with multiple signal classification considering multiple scattering, between the targets[J]. Acoust Soc Am 2004; 115(6): 3042–3047.
[3]. Fink, M. Time reversal of ultrasonic fields. I. Basic principles[J]. IEEE Transactions on Ultrasonics Ferroelectrics & Frequency Control, 1992, 39(5):0-566.
[4]. Prada C , Fink M . Eigenmodes of the time reversal operator: A solution to selective focusing in multiple-target media[J]. Wave Motion, 1994, 20(2):151-163.
[5]. Lehman S K , Devaney A J . Transmission mode time-reversal super-resolution imaging[J]. The Journal of the Acoustical Society of America, 2003, 113(5):2742-2753.

The analysis of variance(ANOVA) method was adopted to evaluate the main effect of the maximum fatigue load(MFL) on the crack growth at the early crack propagation and at the stage near failure in magnesium alloy. In the early stage of crack propagation, the smaller the MFL, the smaller the crack growth and the larger the MFL, the greater the scatter of grown crack. But at the stage near failure, the smaller the MFL, the larger the crack growth and the scatter of grown crack. The variances of grown crack were equal for three levels of the MFL at the early crack propagation and at the stage near failure. Through the residuals diagnostics for the grown crack, the validity of ANOVA was confirmed by verifying the normal distribution and mutual independence of the residuals. The ANOVA verified the MFL factor is highly significant for crack growth. The significance of the levels of MFL factor was also verified through the ANOM test. It was found that the MFL factor and its level affect significantly on the crack growth at the early crack propagation and at the stage near failure in magnesium alloy.

Keywords: ANOVA, Fatigue, Magnesium alloy, Maximum fatigue load(MFL).

[1] F. Briffod, T. Shiraiwa, and M.Enoki, Numerical investigation of the influence of twinning/detwinning on fatigue crack initiation in AZ31 magnesium alloy, Materials Science and Engineering: A, 753, 2019, 79-90.
[2] Y. Nakai, M. Saka, H. Yoshida, K. Asayama, and S. Kikuchi, Fatigue crack initiation site and propagationpaths in high-cycle fatigue of magnesium alloy AZ31, International Journal of Fatigue, 123, 2019, 248-254.
[3] Z. Han, H. Luo, C. Sun, J. Li, M. Papaelias, and C. Davis, Acoustic emission study of fatigue crack propagation in extruded AZ31 magnesium alloy, Materials Science and Engineering: A, 597, 2014, 270-278
[4] S. Ishihara, A. J. McEvily, M. Sato, K. Taniguchi, and T. Goshima, The effect of load ratio on fatigue life and crack propagation behavior of an extruded magnesium alloy, International Journal of Fatigue, 31(11-12), 2009, 1788-1794.
[5] S. Zheng, Q. Yu, and Y. Jiang, An experimental study of fatigue crack propagation in extruded AZ31B magnesium alloy, International Journal of Fatigue, 47, 2013, 174-183.

Underwater communication remains a challenge until nowadays due to limit in deployment of underwater wireless communication. Acoustic communication suffers from several losses due to its dependency on environmental properties like temperature, pressure, salinity, depth and geometric configuration. As the advancement in technology the application of interest nowadays comprises of underwater wireless sensor networks (UWSNs). These networks have a number of sensors deployed in a particular acoustic area between different nodes and ground base stations to perform data collection and monitoring. Presently, UWSNs possess several constraints like cost of deployment, limited battery source, limited bandwidth, propagation delay, routing, topology, security, resource utilization etc. Several methodologies have been introduced to overcome these issues and challenges in last few decades. In this paper a comprehensive review of potential application areas along with research challenges is carried out by comparing several aspects of presently available methods in the field of UWSNs and a new research direction is identified indicating future aspects for further improvements in Underwater Wireless Sensor Networks.

Keywords: Underwater Wireless Sensor Networks (UWSNs), Acoustic Communication, Acoustic Area

[1]. N.-S. N. Ismail, L. A. Hussein, and S. H. S. Ariffin, "Analyzing the performance of acoustic channel in underwater wireless sensor network(UWSN)," in Proceedings of the Asia Modelling Symposium 2010: 4th International Conference on Mathematical Modelling and Computer Simulation, AMS2010, pp. 550–555, Malaysia, May 2010.
[2]. T. Cinar and M. Bulent Orencik, "An underwater acoustic channel model using ray tracing in ns-2," in Proceedings of the 2009 2nd IFIP Wireless Days (WD 2009), pp. 1–6, Paris, December 2009.
[3]. J. Lloret, "Underwater sensor nodes and networks," Sensors, vol. 13, no. 9, pp. 11782–11796, 2013.
[4]. M. Ayaz and A. Abdullah, "Underwater wireless sensor net- works: Routing issues and future challenges," in Proceedings of 7th International Conference on Advances in Mobile Computing and Multimedia, MoMM2009, pp. 370–375, Malaysia, Decem- ber 2009.
[5]. L. Liu, S. Zhou, and J. H. Cui, "Prospects and problems of wireless communication for underwater sensor networks," Wireless Communications and Mobile Computing, vol. 8, no. 8, pp. 977–994, 2008.