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Hasil Pencarian

Ditemukan 2 dokumen yang sesuai dengan query
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Mykhailo Lytvyn
"ABSTRAK
The sessile drop method was implemented to calculate the values of the surface tension coefficient of liquid metals. Appropriate software was developed to increase the data processing efficiency and the accuracy of the obtained results. This paper provides information on the structure and applications of the designed programs as well as the underlying mathematical models used during computations. Since the determination of the surface tension coefficient in this study is based on the recognition of drop outlines from a digital image, the problems of calibration and appropriate photography mode adjustments are mentioned in this paper. In addition,the methods of controlling there search equipment using Arduino shields are described. Finally, the research results are presented in the form of graphs which show the temperature dependence of the studied parameters of metallic samples and compared with the literature data. "
TASK, 2017
600 SBAG 21:1 (2017)
Artikel Jurnal  Universitas Indonesia Library
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Adam Hidana Yudo Saputro
"ABSTRAK
Pengujian elektrokimia menjadi salah satu pengujian yang digemari dalam bidang korosi. Salah satu pengujian yang cukup terkenal saat ini adalah Electrochemical Impedance Spectroscopy dimana menggunakan sistem listrik untuk menganalisis suatu material dalam sistem tertentu. Penerapan metode numerik untuk EIS memungkinkan pengujian EIS dapat dilakukan secara pemodelan untuk kasus-kasus dimana sampel material susah untuk diambil ataupun dilakukan pengujian secara insitu
Pelaksanaan pemodelan numerik pada penelitian ini dibantu dengan metode elemen batas. Respon EIS berupa arus akan di cari dengan mengaplikasikan potensial pada model 2D berbentuk persegi panjang, dengan mendiskritisasikan dengan elemen konstan menjadi 15 elemen. Laplace digunakan sebagai persamaan pembangun, akibat dari sistem yang homogen dan sifat elektronetrality sistem. Respon dari model selanjutnya di terjemahkan dalam bentuk impedansi dan dalam plot Nyquist. Impedansi hasil model numerik ini selanjutnya akan dibandingkan dengan hasil pengujian EIS
Model yang di dapatkan pada penelitian ini secara umum dapat digunakan untuk studi awal dalam memodelkan EIS. Bentuk grafik plot Nyquist terlihat perbedaan yang signifikan. Beberapa perlakuan tambahan harus dilakukan pada tahapan matematis dari model dan penggunaan metode lain pada sistem pengubah respon arus menjadi impedansi.

ABSTRACT
Electrochemical testing become one of popular testing in corrosion study. One of testing is Electrochemicial Impedance Spectroscopy where used electrical system to analyze material in certain system. Implementation of numerical method for EIS is hoped to enable EIS testing conducted only in computation model, escpecially for case where the material is hard to be taken or in situ testing impossible to be conducted.
Numerical modeling in this research is helped by Boundary Element Method. Current as EIS respon is determined by applied potential input in 2D rectangular model, and disctritized by constant element to 15 parts. Laplace equation is used as governing equation as result homogenous and electroneutrality in model system. Model respons is translated to impedance as function of frequency then ploted in Nyquist plot diagram. The result of model impedance is compared to result of experimentally EIS testing
In general, the model could be used as basic study in EIS modeling. Though it has a significant difference between the experimental model, but the shape is follow the common semicircle of Nyquist plot. Some treatment can be conducted in mathematics step of numerical modeling and transferring response to impedance methods"
2016
T46780
UI - Tesis Membership  Universitas Indonesia Library