Electrical Resistance Tomographic by Using Current Injection and Magnetic Field Induction

A critical issue in electrical tomography is ill-posed problems due to low sensitivity. In the electric current injection method, the placement of the injection electrode on the object boundary can influence it. This condition causes the reconstruction result of parameter change far away from the boundary to be inferior in quality. Another excitation method is using magnetic field induction proposed to overcome these problems. Each reconstruction image was obtained using two methods with three types of parameter changes, that represented the edge and the center of the object position. Both reconstruction results are merged and further processed to enhance the quality of the image, based on the average value of the resistivity of each element. The results show that the final image reconstruction has a smaller root mean square error (RMSE) than the electric current injection method

The development of simultaneous transducer ultrasonic with dual-transducer to measure flow velocity in the pipe

There are still several obstacles to calculating fluid flow rate measurement on custody transfer, such as the distribution of one-phase fluid flow rate, less sTable pressure, and fluid flow rate changes, which are still the main problems in the process of a measuring system. To calculate the flow rate of one phase fluid, there is a method often used, namely transit time. In practice, the transit time works to send the ultrasonic pulse from upstream to downstream, which had to have a delay because the transducer must switch the function of a transducer to become transmitter or receiver. So, this paper proposed a new strategy of measurement multipath ultrasonic flowmeter (UFLW) with a simultaneous transit time method using a dual transmitter and receiver. The simultaneous method is a measuring technique that utilizes a pair of ultrasonic transducers as both trigger and receiver. The first transducer serves as the transmitter, while the second functions as the receiver, capturing the signal at the same time without changing their positions or roles. In order to implement the configuration setup, let’s try to use 3 paths configuration with 6 pairs of transducers, 3 on the upstream and 3 on the downstream. To estimate the flow velocity, let’s use long short-term memory (LSTM), which is one of the recurrent neural networks (RNN) architectures in the deep learning algorithm, and to evaluate the performance, let’s use the Bland-Altman plot and root mean squared error (RMSE) and validation loss of the LSTM model. The result shows RMSE 0.289 from the actual flow velocity, which means an LTSM with simultaneous multipath ultrasonic can reduce the error between prediction and actual measuremen

Pengukuran Aliran Udara Dalam Pipa Menggunakan Gelombang Ultrasonik Dengan Metoda Korelasi Silang

Flowmeter ultrasonik merupakan jenis flowmeter yang memanfaatkan gelombang ultrasonik dalam pengukurannya. Metoda yang umum digunakan adalah metoda waktu tempuh. Metoda ini memiliki prinsip pengukuran yang relatif mudah dibanding dengan metoda lainnya. Namun metoda ini kurang sesuai jika digunakan pada aliran fluida yang tidak laminar. Metoda korelasi silang dengan gelombang ultrasonik dapat digunakan untuk mengukur laju aliran fluida yang relatif bersih tetapi profil aliran yang tidak laminar.Pada makalah ini dibahas suatu studi eksperimen metoda korelasi silang untuk mengukur kecepatan aliran udara dalam suatu pipa. Dari hasil pengukuran dengan metoda waktu tempuh diperoleh kecepatan rata-rata aliran yang berbeda dengan yang diperoleh pada metoda korelasi silang. Hasil pengukuran metoda korelasi silang menunjukkan standar deviasi dan presisi yang relatif tinggi, Hal ini menunjukkan bahwa metoda korelasi silang memberikan hasil yang lebih baik pada kondisi aliran tidak laminar seperti aliran udara dalam pipa. Keywords : gelombang ultrasonik, metoda korelasi silang, waktu tunda, demodulasi, aliran turbule

New Reconstruction Method for Needle Contrast Optimization in B-Mode Ultrasound Image by Extracting RF Signal Parameters in Frequency Domain

Ultrasound-guided needle insertion has become standard in medical interventional procedures. Regardless of its advantages, it still has crucial problems related to needle visibility. Some technical factors affect the visibility with non-linear characteristic, i.e. frequency, insertion angle and depth. Here, backscattered signal parameters from measurement were compared to a simulation of a resonance scattering model. Raw radio frequency (RF) data were reconstructed with a new method to represent unique information on total backpropagation from the needle, which consists of non-resonance and resonance scattering components. The result suggests that reconstruction of the needle in B-mode images should be derived from the maximum power spectral density and the energy spectral density to optimize the contrast of the needle. In measurements with the center frequency at 1.87 MHz, the effect of resonance scattering on the total backpropagation around critical angles could be observed more clearly with this method than with standard reconstruction based on the signal envelope. The simulation showed that the fractional bandwidth of the spectrum of the backscattered pressure field centered at 1.87 MHz was relatively optimal at 40% to 100%. So that the simulation of the resonance scattering model can be used to predict the backscattered response from the needle, it must be able to confirm it to the real conditions of RF data with random characteristics. Therefore, extraction of the backscattered pressure field in a simulation with fractional bandwidth should be a concern

Studi Pendahuluan Sistem Tomografi Listrik-Akustik untuk Mendeteksi Kanker Paru-paru

Penelitian ini bertujuan untuk mengkaji kemungkinan diterapkannya sistem tomografi listrik-akustik. Sistem tomografi ini dalam bekerjanya menggunakan injeksi pulsa arus listrik sehingga dihasilkan dua data sekaligus, yaitu sinyal akustik dan potensial listrik. Data sinyal akustik memiliki potensi untuk menghasilkan citra resolusi spasial tinggi, sedang data potensial listrik memiliki potensi untuk menghasilkan citra kontras tinggi. Metode yang dilakukan dalam penelitian ini adalah melakukan kajian studi tentang terpenuhinya kemungkinan syarat-syarat yang dibutuhkan. Untuk studi awal ini dilakukan studi simulasi untuk memperoleh data sinyal akustik yang kemudian dilakukan kajian analisis. Hasil dari penelitian ini menunjukkan bahwa sinyal akustik prospektif untuk digunakan dalam deteksi kanker paru karena kontrasnya nilai akustik organ paru dan jaringan kanker paru.

Design and Characterization of Ultrasonic Langevin Transducer 20 kHz Using a Stepped Horn Front-Mass

Ultrasonication is a method that is widely used in various fields. One of its applications is to accelerate the process of homogenization, emulsification, and extraction. In the ultrasonicator system, the transducer is an extremely important device. The resonant frequency, longitudinal vibration amplitude, and electromechanical coupling are the targets in designing an ultrasonic transducer. In this investigation, the main contribution was the development of a simple and effective method for mechanically tuning the resonant frequency of the transducer by adding mass to the front end of the mass or stepped horn. This study also aimed to obtain optimal results by examining the effects of geometric dimensions, bolt prestress, stress distribution, resonant frequency, amplitude, and electrical impedance. The ultrasonic transducer model was designed with a resonant frequency of 20 kHz and simulated using the finite element analysis. The steps involved included calculating the dimensions and geometric structure of the transducer, modeling using the finite-element method, and experimental validation. The simulation results and measurements showed that the series resonant frequency, electrical impedance, and effective electromechanical coupling of the Model-4 transducer 16∙13 mm radiator configuration were 20.15 kHz, 100 Ω, and 0.2229 from the simulation results, and 20.17 kHz, 24.91 Ω, and 0.2033 from the measurement results. A percentage difference, or relative error, of 0.1% was obtained between the simulation and the experimental results for this Model-4 with bolt prestressing at 15 kN

Pengaruh Aplikasi Pupuk Kandang Sapi Dan Bokashi Sampah Kota Terhadap Pertumbuhan Dan Hasil Tanaman Mentimun (Cucumis sativus L)

Pengaruh Aplikasi Pupuk kandang Sapi dan Bokashi Sampah Kota Terhadap Pertumbuhan dan Produksi Tanaman Mentimun (Cucumis sativus L). Penelitian ini dilaksanakan di kebun percobaan Universitas Asahan, jalan jend. Ahmad Yani, Kecamatan Kisaran Timur Kabupaten Asahan dengan topogafi dan ketinggian tempat ± 20 m dpl. dilakukan pada bulan Februari s/d April tahun 2021. Penelitian ini disusun berdasarkan Rancangan Acak Kelompok (RAK) Faktorial dengan 2 faktor perlakuan dan 3 ulangan. Faktor pertama adalah aplikasi pupuk kandang sapi dengan 4 taraf yaitu : K0 = 0 kg plot-1, K1 = 1 kg plot-1,K2 = 2 kg plot-1 dan K3 = 3 kg plot-1. Faktor kedua adalah aplikasi bokashi sampah kota, dengan 3 taraf yaitu S0 = 0 kg plot-1, S1 = 1 kg plot-1dan S2 = 2 kg plot-1. Hasil penelitian menunjukkan bahwa aplikasi pupuk kandang sapi menunjukkan pengaruh nyata terhadap diameter buah, panjang buah, produksi tanaman per sample, produksi tanaman per plot dengan perlakuan terbaik yaitu 3 kg plot-1. Aplikasi bokashi sampah kota tidak berpengaruh nyata terhadap seluruh parameter amatan tanaman mentimun. Interaksi aplikasi pupuk kandang sapi dan bokashi sampah kota tidak berpengaruh nyata terhadap seluruh parameter amatan tanaman mentimu

Pencitraan Tomografi Elektrik dengan Elektroda Planar di Permukaan

Tomografi Elektrik merupakan metoda pencitraan distribusi resistivitas listrik suatu objek berdasarka pengukuran beda potensial dan arus listrik yang terjadi pada bidang batas objek. Pada studi ini dikaji penerapan tomografi elektrik untuk pencitraan objek di bawah permukaan seperti di bawah permukaan tanah, dengan menggunakan susunan elektroda di atas permukaan dengan konfigurasi planar atau dalam satu baris. Untuk rekonstruksi citra, digunakan algoritma rekonstruksi berbasis model, dengan menggunakan metoda elemen hingga untuk pemodelan objek dan metoda Newton_Raphson untuk perhitungan distribusi resistivitas. Untuk mengatasi persoalan ill-posed, diterapkan metoda regularisasi Tikhonov. Dari hasil simulasi numerik dengan pendekatan model objek segi empat, diperoleh bahwa target dalam objek akan dapat direkonstruksi lebih baik jika terletak semakin dekat ke permukaan. Kata kunci: tomografi elektrik, elektroda permukaan, metoda elemen hingga, metoda Newton-rhapsonAbstractElectrical Tomography is a method for imaging the electrical resistivity distribution of an object by measuring the potential difference and electric current that occurs in the object boundary. This study examined the application of electrical tomography for imaging the subsurface object, using an arrangement of electrodes on the surface in planar configuration or single row. Model-based reconstruction algorithm is used for image reconstruction, using the finite element method for modeling object and Newton-Raphson method for measuring the resistivity distribution. Tikhonov regularization method is used to solve the ill-posed problem. From the results of numerical simulation with model-based approach for rectangular object, the target in an object will be reconstructed better if located closer to the surface.    Keywords: electrical tomography, surface electrode, finite element method, Newton-rhapson metho

Design and Characterization of Ultrasonic Langevin Transducer 20 kHz Using a Stepped Horn Front-Mass

Ultrasonication is a method that is widely used in various fields. One of its applications is to accelerate the process of homogenization, emulsification, and extraction. In the ultrasonicator system, the transducer is an extremely important device. The resonant frequency, longitudinal vibration amplitude, and electromechanical coupling are the targets in designing an ultrasonic transducer. In this investigation, the main contribution was the development of a simple and effective method for mechanically tuning the resonant frequency of the transducer by adding mass to the front end of the mass or stepped horn. This study also aimed to obtain optimal results by examining the effects of geometric dimensions, bolt prestress, stress distribution, resonant frequency, amplitude, and electrical impedance. The ultrasonic transducer model was designed with a resonant frequency of 20 kHz and simulated using the finite element analysis. The steps involved included calculating the dimensions and geometric structure of the transducer, modeling using the finite-element method, and experimental validation. The simulation results and measurements showed that the series resonant frequency, electrical impedance, and effective electromechanical coupling of the Model-4 transducer 16∙13 mm radiator configuration were 20.15 kHz, 100 Ω, and 0.2229 from the simulation results, and 20.17 kHz, 24.91 Ω, and 0.2033 from the measurement results. A percentage difference, or relative error, of 0.1% was obtained between the simulation and the experimental results for this Model-4 with bolt prestressing at 15 kN

Simulasi Perambatan Gelombang Ultrasonik dengan Model Berkas Multi Gaussian dan Model Pengukuran Thompson Grey

Transduser ultrasonik adalah komponen untuk pembangkitan gelombang ultrasonik. Dalam aplikasi tertentu, pemilihan transduser yang tepat ditentukan oleh parameter yaitu, frekuensi, diameter, voltage drive, dan jarak  antar transduser. Salah satu cara yang efektif untuk menentukan parameter transduser yang sesuai adalah dengan melakukan simulasi perambatan gelombang ultrasonik yang dihasilkan transduser dengan berbagai variasi parameternya. Pada studi ini dilakukan kajian simulasi perambatan gelombang ultrasonik untuk transduser tercelup berbentuk piston dengan pendekatan model berkas gelombang multi-Gaussian dan model pengukuran Thompson-Gray. Simulasi menggunakan perangkat lunak yang dibuat berupa graphical user interface. Parameter-parameter transduser divariasikan untuk pengamatan pada berbagai kondisi. Hasil kajian simulasi divalidasi dengan hasil pengukuran eksperimen perambatan gelombang ultrasonik dari transduser tercelup berbentuk piston. Dari kajian, diperoleh perbedaan antara hasil simulasi dan eksperimen adalah 3.55% untuk nilai selisih tegangan keluaran dan 0.17% untuk nilai selisih waktu tempuh