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A theoretical study based on density functional theory for H 2 O dissociation on the metal surface of Pt(111) alloyed simultaneously with Ru and Mo was performed. The determination of the minimum energy path using the climbing image nudged elastic band (CI-NEB) method shows that the dissociation reaction of H 2 O with this catalyst requires almost no energy cost. This dissociation reaction is not only kinetically favored but also almost thermodynamically neutral and somewhat exothermic. The electronic structure analysis showed that much more charge was released in Mo and was used to bind the adsorbed hydroxyl (OH ad ). Further analyses of the density of states (DOS) showed that the large number of orbitals that overlap when OH binds to Mo are responsible for the stabilization of the OH-surface bond. The stability of the OH ad fragment on the surface is believed to be a descriptor for the dissociation of H 2 O with an almost spontaneous process.

The wave energy power generation-pendulum system (WEPG-PS) is a four-wheeled instrument designed to convert wave power into electric energy. The first wheel is connected to the pendulum by a double freewheel, the second and third are ordinary wheels, while the fourth is a converter component that is axially connected to the electric generator. This design used the Euler-Lagrange formalism and Runge-Kutta method to examine an ideal dimension and determine the numerical solution of the equation of motion related to the rotation speed of the wheels. The result showed that the WEPG-PS' converter system rotated properly when its mass, length, and moment of inertia are 10 kg, 2.0 m, and 0.25 kgm2, respectively. This is in addition to when the radius of the first, second, third, and fourth wheels are 0.5, 0.4, 0.2, and 0.01 m, with inertia values of 0.005, 0.004, 0.003, and 0.1 kgm2. The converter system has the ability to rotate the fourth wheel, which acts as the handle of an electric generator at an angular frequency of approximately 500 - 600 rad/s. The converter system is optimally rotated when driven by a minimum force of 5 N and maximum friction of 0.05. Therefore, the system is used to generate electricity at an amplitude of 0.3 - 0.61 m, 220 V with 50 Hz. Besides, the lower rotation speed and frequency of the energy converter of the WEPG-PS (300 rad/s) and induction generator (50 Hz) were able to generate electric power of 7.5 kW. ©2020. CBIORE-IJRED. All rights reserved

Penalaan gambang laras slendro selama ini dilakukan dengan mempertimbangkan perasaan yaitu perasaan enak atau tidak enak bunyi didengar. Dengan cara ini keselarasan dapat berubah seiring dengan perasaan pengrajin, selain itu akan berbeda pula antara pengrajin satu dengan pengrajin lainnya. Penelitian bertujuan untuk membuat sistem yang mampu menggantikan orang dalam penalaan nada berdasarkan Artificial Intelligence. Sistem menganalisis karakteristik tiap nada bilah dengan meninjau frekuensi fundamental mengunakan algoritma Fast Fourier Transform (FFT) yang dimiliki oleh program Matlab, dan meninjau hubungan antara ukuran bilah dan frekuensi yang dihasilkan. Sebuah program Jaringan Syaraf Tiruan (JST) dibuat untuk membantu dalam identifikasi dan untuk mempermudah menjalankan program dibuat tampilan sederhana menggunakan GUI (Graphical User Interface). Hasil penelitian menunjukkan bahwa frekuensi fundamental dapat ditentukan dari puncak tertinggi dalam sebuah spektrum frekuensi dan ukuran bilah berpengaruh terhadap pembuatan nada. Sistem penala gambang slendro menggunakan JST dapat mendeteksi secara benar 47,5% sampel dalam pengujian

Pico hydropower is a type of hydropower that can produce electric power under or equal to 5000 Watt. Consisting of one turbine to rotate one generator, it has been used in remote areas to provide for electricity supply. Although the system serves quite well, sometimes the necessity for electricity supply is larger than the system can supply. The solution would be to build two pico hydropower systems. However, the cost of such a solution will also double. In addition to that, the water source and landscape may not sustain more than one pico hydropower. An alternative solution that is being proposed to resolve the problem is by using one turbine to rotate two electric generators in a unity pico hydropower system. The objective of the study concerning the proposed solution is to obtain a configuration and dimension of the energy converter. They are sought by determining the equation of motion for energy converter which is configured in several wheels. The equation of motion, which is in differential form, is obtained using the Euler-Lagrange procedure in classical mechanics. Both configuration and dimension of energy converter are solved using numerical methods. The numerical method used in this study is the fourth-order of the Runge-Kutta method for analyzing some physical parameters i.e.: angular velocity of the energy converter, friction coefficient, driving force, radius and inertia of the wheels. By employing varying numbers in the computational process using the fourth-order of the Runge-Kutta method in Matlab, we seek that the pico hydropower system with ideal configuration and dimension of energy converter based on the radius of the wheels are configured as r 1> r 3>r 2>r 4>r 5=r 6. The configuration yield an optimum rotation of the coupled wheels (r 5 and r 6) as a representation of the electric generator’s axis although the thrust is assumed lower. The design expected to be a solution for optimizing a pico hydropower, especially in remote areas with lower water flow.