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"Heat engine thermoacoustic mengkonversi panas menjadi daya akustik tanpa adanya komponen yang bergerak. Untuk mengembangkan lebih jauh performa dari termoakustik jenis ini, maka diperlukan karakterisasi dari parameter-parameter yang bekerja. Pada pengujian kali ini dilakukan karakterisasi termoakustik berdasarkan posisi stack dan onset temperature dengan tujuan untuk mengetahui posisi stack dan besaran nilai onset temperature yang optimal. Variasi yang dilakukan pada pengujian ini untuk posisi stack yaitu pada posisi 20, 30, 40, 50, 60, 70, 80, 90, dan 100 mm dari ujung tabung tertutup, sedangkan untuk variasi onset temperatur dilakukan pada suhu awal termoakustik mulai bekerja (terendah 3950C) sampai 5000C. Pengujian ini dilakukan dengan menggunakan stack yang terbuat dari bahan dasar keramik dan menggunakan pemanas berbentuk nozzle serta panjang resonator 200 mm. Kecenderungan daya akustik yang dihasilkan mempunyai kemiripan dengan persamaan yang diusulkan oleh Swift et al [1], dengan daya terbesar yang dihasilkan terjadi pada saat posisi stack 50 mm dari ujung tabung tertutup dan onset temperature 5000C sebesar 9,81x10-4 Watt

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Heat engine thermoacoustic converts heat into acoustic power with no moving parts. In order to improve the performance of the heat engine termoacoustic, working parameters should be optimized. In this examination, the thermoacoustic is characterized based on stack position and onset temperature in order to acknowledge the optimal value from both parameters. Stack position varieties chosen for this examination are 20, 30, 40, 50, 60, 70, 80, 90 and 100 mm from close-end tube, and onset temperature varieties chosen start from the lowest temperature that the engine regarded to be working (lowest 4100C) to 5000C. This examination uses nozzle shaped heater, ceramic stack, and 200 mm glass resonator. This experimental results indentified follows the equation proposed by Swift et al [1,] which have the largest value of acoustic power (9,81x10-4 Watts) where the stack placed 50 mm from close-end tube and the onset temperature regulated for 5000C."

"Themes that are highlighted include :

• the role of language : the models developed for engineering design have resulted in new ways of talking about technological systems
• communities of practice : related to the previous point, particular engineering communities have particular ways of sharing and developing knowledge
• graphical (re)presentation : engineers have developed many ways of reducing quite complex mathematical models to more simple representations
• reification : highly abstract mathematical models are turned into ‘objects’ that can be manipulated almost like components of a physical system
• machines : not only the currently ubiquitous digital computer, but also older analogue devices, slide rules, physical models, wind tunnels and other small-scale simulators, as well as mechanical, electrical and electronic analogue computers
• mathematics and modelling as a bridging tool between disciplines

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"This monograph deals with theoretical aspects and numerical simulations of the interaction of electromagnetic fields with nonlinear materials. It focuses in particular on media with nonlinear polarization properties. It addresses the direct problem of nonlinear Electrodynamics, that is to understand the nonlinear behavior in the induced polarization and to analyze or even to control its impact on the propagation of electromagnetic fields in the matter. The book gives a comprehensive presentation of the results obtained by the authors during the last decade and put those findings in a broader, unified context and extends them in several directions.It is divided into eight chapters and three appendices. Chapter 1 starts from the Maxwell’s equations and develops a wave propagation theory in plate-like media with nonlinear polarizability. In chapter 2 a theoretical framework in terms of weak solutions is given in order to prove the existence and uniqueness of a solution of the semilinear boundary-value problem derived in the first chapter. Chapter 3 presents a different approach to the solvability theory of the reduced frequency-domain model. Here the boundary-value problem is reduced to finding solutions of a system of one-dimensional nonlinear Hammerstein integral equations. Chapter 4 describes an approach to the spectral analysis of the linearized system of integral equations. Chapters 5 and 6 are devoted to the numerical approximation of the solutions of the corresponding mathematical models. Chapter 7 contains detailed descriptions, discussions and evaluations of the numerical experiments. Finally, chapter 8 gives a summary of the results and an outlook for future work."

"This book presents recent developments in nonlinear dynamics with an emphasis on complex systems. The volume illustrates new methods to characterize the solutions of nonlinear dynamics associated with complex systems. This book contains the following topics: new solutions of the functional equations, optimization algorithm for traveling salesman problem, fractals, control, fractional calculus models, fractional discretization, local fractional partial differential equations and their applications, and solutions of fractional kinetic equations."