46 research outputs found
Dinamika Pembalikan Magnetisasi Nanoblock Berbasis Kobalt Teredam Kuat di Bawah Stimulasi Medan Panas
Dinamika pembalikan magnetisasi pada nanoblock berbasis kobalt teredam kuat yang distimulasi oleh pemanasan pulsa telah dieksplorasi secara numerik untuk model parallelepiped dengan ukuran 50×50×20 nm3. Pengaturan simulasi diimplementasikan untuk mengevaluasi dua parameter penting dalam perekaman magnetik dengan bantuan panas, yaitu stabilitas termal, dan konsumsi medan tulis. Stabilitas termal diukur melalui medan magnet induksi yang meningkat secara linear hingga 2 Tesla selama 2,5 ns pada kesetimbangan termal terhadap lingkungan. Dalam simulasi sistem dengan stimulasi medan panas, konsumsi medan tulis diselidiki menggunakan dua jenis pulsa, yaitu medan magnet, dan pulsa medan termal. Simulasi ini didasarkan pada persamaan Landau-Lifshift-Gilbert yang memasukkan teorema disipasi fluktuasi dalam menghitung efek fluktuasi termal. Selain itu, parameter-parameter material yang tergantung suhu, yaitu saturasi magnetik, anisotropi magnetik, dan interaksi pertukaran, juga diperhitungkan. Sebagai hasilnya, nanoblock berbasis kobalt yang teredam kuat memiliki penghalang energi magnetik yang tinggi untuk mencegah batasan superparamagnetik. Selain itu, medan penulisan dapat dikontrol melalui pengaturan periode pemanasan, dan juga melalui manipulasi sifat magnetik seperti redaman magnetik intrinsik
Mekanisme Proses Deposisi Gadolinium Pada Dentate Nucleus: Sebuah Studi Monte Carlo
GBCA (Gadolinium-Based Contrast Agent) adalah material kontras yang digunakan untuk peningkatan pencitraan MRI (Magnetic Resonance Image). Gadolinium beracun bagi manusia, oleh karena itu diberikan kepada manusia dalam bentuk kelat. Gadolinium memiliki efek toksik yaitu terlepas dari kelat dan mengendap dalam jaringan. Penelitian ini bertujuan untuk mengetahui mekanisme gadolinium yang terdeposit dan mengendap dalam otak di dentate nucleus yang disebabkan oleh karena terlepasnya elat dari gadolinium yang menjadi penangkal ketoksikan. Analisa simulasi dilakukan dengan menggunakan simulasi Monte Carlo Cell untuk mensimulasikan pergerakan dari reaksi molekul di dalam organ dan menggunakan aplikasi Originlab untuk analisis grafik yang dihasilkan dari setiap molekul gadolinium yang dilihat dari react data hasil simulasi. Visualisasi dan pembuatan model cerebellum serta dentate nucleus menggunakan aplikasi blender 2.93. Bentuk geometri yang digunakan dalam simulasi dibuat menyerupai cerebellum dan dentate nucleus. Kecepatan difusi gadolinium akan meningkat seiring dengan jumlah molekul gadolinium yang masuk. Dalam penelitian ini, pada simulasi dengan jumlah molekul gadolinium 8000 dan berinteraksi dengan zat besi menunjukkan proses transmetalasi yang paling cepat dibanding jumlah molekul Gadolinium yang dibawah 8000. Gadolinium yang masuk ke dalam dentate nucleus bereaksi dengan zat besi yang ada di organ tersebut sehingga kelat yang mengikat gadolinium terlepas lalu mengikat zat besi dan kemudian gadolinium menjadi ion bebas dan terdeposisi di dentate nucleus
Investigasi Pengaruh Jarak Celah Sinapsis dengan menggunakan Metode Monte Carlo
Neurons in the human brain are interconnected and influence each other. Signal integration in brain is determined by the size and the fast synapses response kinetics. This research aims to study the effect of synaptic cleft distance on signaling through a diffusion process using the Monte Carlo Cell simulation program. This research is important to investigate the diffusion process in the body related to the effect of diffusion on signaling if the cleft, area, and concentration are varied. MCell is a probabilistic simulation which a solution of a problem is given based on the probability calculation process. This study uses modeling 3 spherical compartments representing pre-synapses, post-synapses, and neurons as the outer boundary of synapses and as a cleft between pre-synapses and post-synapses. The simulation results showed that the effect of change in the cleft distance on molecular distribution was 98,86%. The narrower size of the cleft distance causes faster molecular distribution. The broader the receptor area (6;12;18;24) causes the molecules to be distributed to increase ((1661;2173;2249;2264)moles). An increase in the amount of concentration (2000;4000;6000;8000) also makes the diffusion rate faster ((1380;2806.25;4203.75;5565)moles/s). The faster the diffusion rate indicates that the signaling process is getting faster
Desain Modul Pembelajaran Mandiri Tentang Gerak Parabola Pada Bidang Miring Tanpa Gesekan Udara
Generally, the learning about projectile motion on inclined surface neglecting air friction can not be delivered during the meeting hours because of the limited time. One way that can be done is by doing independent learning about projectile motion on inclined surface neglecting air friction which is assisted by an independent learning module. The purpose of this study is to design an independent learning module of projectile motion on inclined surface neglecting air friction and to investigate the effectiveness of the module toward undergraduate students’ understanding. Hopefully, this module can enrich the mechanic's modules for the undergraduate students and support them in learning about projectile motion on the inclined surface out of the meeting hours so that they can learn about the projectile motion comprehensively. The method of this study is the ADDIE model of development method consisting of Analysis, Design, Development, Implementation, and Evaluation steps. This independent learning module is applied to three freshmen of the Physics and Physics Education Department. Based on the observation sheet, the undergraduate students were able to do 88% of the module correctly, they also give 90% positive response to the statements of the module, and gets an average evaluation score of 75. Therefore, this independent learning module about projectile motion on inclined surface neglecting air friction is effective in assisting undergraduate students to understand the projectile motion on inclined surface neglecting air friction material
Karakterisasi Nanopartikel Fe3O4 dan Aplikasinya dalam Adsorpsi Ni(II) DAN Co(II)
Nanopartikel magnetik Fe3O4 (MNPs) disintesis dari FeSO4•5H2O sebagai sumber Fe dengan penambahan NH4OH melalui proses sol-gel. MNPs digunakan untuk menyerap larutan Ni (II) dan Co (II). Larutan Ni (II) dan Co (II) dianalisis menggunakan spektrofotometer HACH. MNPs dikarakterisasi menggunakan X-Ray Diffraction (XRD), Transmission Electron Microscope (TEM), dan Scanning Electron Microscope (SEM). Hasil penelitian menunjukkan bahwa ukuran partikel MNPs dari 30 nm sampai dengan 70 nm. Dalam proses adsorpsi, MNPs cenderung menjerap larutan yang mengandung logam Co (II) daripada Ni (II). Berdasarkan analisis dengan spektrofotometer HACH, penurunan konsentrasi hanya terjadi pada larutan Co (II) sebesar 55,31% dari 0,47 ppm menjadi 0,21 ppm.
A micromagnetic study: lateral size dependence of the macroscopic properties of rectangular parallelepiped Cobalt-ferrite nanoferromagnetic
The purpose of this study is to provide systematic information through micromagnetic simulations related to the impact of particle size on the magnetic characteristics of Cobalt-ferrite MNP. The micromagnetic computations performed were based on LLG equation. The MNPs sample was simulated in the form of a rectangular parallelepiped with a thickness of 20 nm and square surface with lateral length varies from 10 to 80 nm at an interval of 10 nm. The results of this study indicate that the size changes in Cobalt-ferrite MNP have a significant impact on various magnetic properties, such as the magnitude of the barrier energy, coercive and nucleation fields, magnetization rate, magnetization curve profile, and magnetization mode.Cobalt-ferrite MNP with a size of 10 nm shows a single domain with a relatively short magnetization reversal time and high coercive field
Design of measuring flow velocity device for liquid fluid with venturi meter principles based on Arduino
Fluid flow velocity in physics can be found on the principle of venturi meter. The Fluid flow concept is easy to understand if visualized. We need a learning media of fluid velocity, so the concept can understanding. Design of this tool aims to help students understand the fluid flow velocity. Data is taken automatically by Arduino-based water flow sensor, with speed change at the speed knop. Based on the design result of the tool which can be obtained by measuring the fluid flow velocity at a speed greater than 0.36 m/s, and proved by graph analysis logarithmic between velocity values of magnitude theory (Vtheory = 0.5x + 0.7934 m/s ) and tool speed (Vtool = 0.5825x + 1.129 m/s). The speed difference between the theory and the tool indicates the magnitude of the frictional speed due to the turbulent flow. So it can be concluded the design of this tool can be used as a learning media to help students in understanding the topic of fluid