Jurnal Ilmu Fisika (JIF)
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Efficiency at Maximum Power of Endoreversible Quantum Otto Engine with Partial Thermalization in 3D Harmonic Potential
Get PDFWe study the partial thermalization to the effect of efficiency at maximum power (EMP) of a quantum Otto engine using Bose-Einstein Condensation in 3D harmonic potential. Partial thermalization occurs at a finite-time isochoric process, preventing the medium from achieving equilibrium with reservoirs, leaving it in a state of residual coherence. Under these circumstances, the performance of the engine can be seen from its power and EMP. The 3D harmonic potential is used to generate an excitation of energy during the expansion and compression. The total energy is defined by the total work done in a cycle. Using Fourier’s law in conduction, we found that power explicitly depends on the duration of heating and cooling stroke time and efficiency of the engine; that is the higher stroke time and efficiency, the less power output. In order to find EMP, we maximize power with respect to compression ratio κ, and we found that EMP also depends on the isochoric heating and cooling process. By varying the stroke time of the isochoric process, EMP slightly decreases with increasing isochoric time due to entropy production. However, adjusting cooling stroke time more extended than heating stroke time could significantly improve the EMP of Otto Engine
Particle Size Improvement and Layer Absorption of Metil Halida MAPbI3 Perovskite Doping Phenethylammonium Iodide (PEAI)
Get PDFThis study aims to determine the effect of phenethylammonium iodide (PEAI) doping on grain size and absorption of the methylammonium lead iodide (MAPbI3) perovskite layer. The MAPbI3 perovskite layer is interesting to study because of its potential application in perovskite solar cells. In this study, the preparation of MAPbI3 perovskite layer with PEAI doping variation using a 2-step spin-coating method. The surface morphology of MAPbI3 shows an increase in grain size with the addition of PEAI doping variation. The optimum grain size is shown by adding 1.0 mg/ml PEAI doping variation, which is 117 ± 1.19 nm with a smooth surface morphology and tends to be homogeneous. X-ray diffraction (XRD) results on Perovskite MAPbI3 showed no difference in peaks with the addition of PEAI doping. However, there is only a slight angle shift of 2 theta, 0.05° at the main peak (110) and (220), so it will not change the cubic structure of MAPbI3 crystal. The ultra violet visible (UV-Vis) graph shows an increase in absorbance of Perovskite MAPbI3 with the addition of PEAI doping in the wavelength range of 400-550 nm. This research is expected to be a foundation for developing more efficient and stable solar cells.Penelitian ini bertujuan untuk mengetahui pengaruh doping Phenylethylammonium Iodide (PEAI) terhadap ukuran butir dan serapan dari lapisan perovskit MAPbI3. Lapisan perovskit MAPbI3 menarik untuk diteliti karena potensi aplikasinya pada teknologi sel surya perovskite. Dalam penelitian ini, pembuatan lapisan perovskit MAPbI3 dengan variasi doping PEAI menggunakan metode spin-coating 2 langkah. Morfologi permukaan MAPbI3 menunjukkan terjadinya peningkatan ukuran butir seiring penambahan variasi doping PEAI. Hasil optimum ukuran butir ditunjukkan pada penambahan variasi doping 1,0 mg/ml PEAI yaitu 117 ± 1.19 nm dengan morfologi permukaan yang halus dan cenderung homogen. Hasil difraksi sinar-X pada Perovskit MAPbI3 menunjukkan tidak ada perbedaan puncak dengan penambahan doping PEAI. Namun hanya terjadi sedikit pergeseran sudut 2 teta yaitu 0.05O pada puncak utama (110) dan (220) sehingga tidak akan merubah struktur kubik kristal MAPbI3. Grafik UV-Vis menunjukkan adanya peningkatan absorbansi Perovskit MAPbI3 dengan penambahan doping PEAI pada rentang panjang gelombang 400-550 nm. Penelitian ini diharapkan dapat menjadi landasan untuk pengembangan sel surya yang lebih efisien dan stabil di masa depan
PENGOLAHAN CITRA DIGITAL UNTUK PENENTUAN KECEPATAN ALIRAN DARAH DI JANTUNG BERDASARKAN EFEK DOPPLER
No full textA research study was conducted to estimate and visualize 2D vectors of blood flow in the heart using image processing algorithms to determine Doppler velocity at each point. The study used secondary data from ten patients who provided informed consent, encompassing healthy and unhealthy hearts. ECD image data were collected using a Philips epiq 7C machine in DICOM format. The image processing tasks, including area segmentation, flow velocity analysis, and area smoothing, were carried out using MATLAB R2016b software. These processes aimed to eliminate noise and other disturbances, enhancing the accuracy of blood flow velocity estimation in the heart. The study's findings included estimations and 2D vector visualizations representing the average blood flow velocity at each point within the heart. These achievements were made possible using image processing techniques to correct the acquired images, ensuring precise measurement of blood flow speed. Among the collected data, one patient exhibited indications of a healthy heart, with an average blood flow velocity of 40.2513 cm/s, a maximum speed of 68.5807 cm/s, and a minimum speed of 33.6971 cm/s. Deviations from the normal range of blood flow speeds were considered as potential abnormalities in heart health.Telah dilakukan penelitian tentang perolehan estimasi dan visualisasi vektor 2D aliran darah di jantung dengan menentukan kecepatan Doppler disetiap titik melalui algoritma image processing. Penelitian ini menggunakan data sekunder pasien yang telah diindikasi jantung sehat dan tidak sehat sebanyak 10 pasien dengan permintaan informed concent. Data citra ECD diperoleh menggunakan Philips epiq 7C dalam format DICOM. Penentuan estimasi serta visualisasi vektor 2D dilakukan proses pengolahan citra menggunakan software MATLAB R2016b. Proses pengolahan citra dilakukan dengan proses segmentasi area, Dealiasing kecepatan aliran dan smoothing area untuk menghilangkan noise dan gangguan lainnya dalam meningkatkam estimasi kecepatan aliran darah di jantung. Hasil penelitian ini didapatkan estimasi dan visualisasi vektor 2D disetiap titik mewakili kecepatan rata-rata kecepatan aliran darah dijantung. Pencapaiannya berdasarkan pemrosesan dan proses pengolahan citra untuk mengoreksi citra mendapatkan kecepatan aliran darah. Kecepatan aliran darah normal sebesar 40,2513 cm/s, kecepatan aliran darah tertinggi sebesar 68,5807 cm/s dan kecepatan aliran darah terendah sebesar 33,6971 cm/s. Frekuensi ultrasonik yang diterima pasien tidak jauh berbeda dengan frekuensi masukan dan tidak dipengaruhi oleh kecepatan aliran darah dalam tubuh pasien. Frekuensi masukan yang diberikan melalui transduser sebesar 2,5 MH
Sintesis Carbon Dots (CDs) Berfluoresensi untuk Bioimaging dengan Metode Ablasi Laser.
No full textCarbon Dots (CDs) were synthesized using laser ablation by focusing the laser beam on carbon (Tea) material in colloid (CH3) for 3 hours. UV-Vis spectroscopic and fluorometric characterization showed absorption of the wavelength peaks caused by the control treatment and after laser ablation and coating using Poly Ethylene Glycol (PEG400). The excitation and emission energies are formulations of CDs absorbance wavelength and fluorescence intensity. The absorbance coefficient is obtained based on the absorbance value of the cuvette thickness. The transmittance value (T) is obtained based on the absorption coefficient multiplied by 100%. CD fluorescence wavelength based on control parameters was 489 nm. After laser ablation was 496 nm, and after coating was 511 nm. CDs morphology and size characteristics are 4 nm to 10 nm based on TEM measurements. Fluorescence analysis for bioimaging applications on the luminescence intensity value of internalized blue CDs in zebrafish eye organs. The average intensity of CDs in the eye organs, gill, intestinal, dorsal, and tail injection points was 88.15 %, 91.58 %, 92.76 %, and 0.00 %
An Exact Solution of Nonlinear Schrödinger Equation in a Lossy Fiber System Using Direct Solution Method
Get PDFWe present an exact solution of the nonlinear Schrödinger equation (NLSE) for beam propagation in nonlinear fiber optics. It is a lossy fiber system with the beam as solitons. Fiber losses are understood to reduce the peak power of solitons along the fiber length. That is due to its value depending on the fiber attenuation constant of α. Considering fiber loss features on the equation, we write one set modification of the NLSE and make models the main topic of our work. We solved the model and found a straightforward analytical solution of modified NLSE for the system via the direct solution method. To the best of our knowledge, no literature has presented such as solution yet. By substituting them into equations, we validate solutions. It is valid as an exact solution to the NLSE. Lastly, we found a solution offering soliton propagation suitable for the system under study
Rigid Procedure to Calculate the Melting Point of Metal Using the Solid-Liquid Phase (Coexistence) Method
Get PDFMelting point, particularly metal, is one of the important data for many applications. For developing new materials, adequate theories for melting point are very crucial. The determination of melting point using the popular phase-change curve method is very easy but usually overestimate. In current work, we determine the melting point of a pure metal (iron) using the method of solid-liquid phase coexistence. For this goal, molecular dynamics simulation was applied to obtain data of trajectories of atoms. Simulation (LAMMPS) and data analysis (OVITO) procedures are strictly applied to obtain the accurate melting point of iron based on the obtained trajectories data. For initial structure design of simulation, we used the ATOMSK program. The melting point of iron obtained using the phase change curve (PCC) method is about 2750 K < TPCC < 3250 K and using the coexistence phase (CP) method is TCP = 2325 K. A more accurate calculation needs to include defects factor in the simulated material and calculation. In this research we use the Morse potential to represent all of the atomic interaction among atoms of Fe material
Penghambatan Korosi Melalui Adsorpsi Ekstrak Kulit Kakao (Theobroma cacao) pada Permukaan Baja: Metode Eksperimen dan DFT
No full textSteel surface coating has been carried out using the immersion method in an inhibitor of cacao (Theobroma cacao) peel extract for 24, 72, 120, and 168 hours. The corrosion treatment was performed using HCl with different immersion time of 48, 96, and 144 hours after coating process with the inhibitor. Corrosion testing with the weight loss method gave the best results with the lowest corrosion rate of 0.2972 mg.cm2/hour and inhibition efficiency of 74.7128% for steel samples with the longest immersion time in inhibitor. Optical microscopy and SEM images indicated that the longer the immersion time in the inhibitor, the better (i.e., fewer holes and cracks) the surface morphology of the steel. The appearance of four sharp peaks in the XRD diffractogram indicated that the samples with the lowest corrosion rate produced Fe and C crystalline phases due to the reaction between the steel surface and the inhibitor. A quantum chemical analysis using the DFT (Density Functional Theory) method also produced a fairly high inhibition efficiency and was close to the experimental results of 80.2098%.Telah dilakukan pelapisan permukaan baja dengan metode perendaman dalam inhibitor ekstrak kulit kakao (Theobroma cacao) selama 24, 72, 120, dan 168 jam. Korosi dilakukan perlakuan menggunakan HCl dengan variasi perendaman selama 48, 96, dan 144 jam yang diberikan setelah proses pelapisan inhibitor. Pengujian korosi dengan metode weight loss memberikan hasil terbaik dengan laju korosi terendah sebesar 0,2972 mg.cm2/jam dan efisiensi inhibisi sebesar 74,7128% untuk sampel baja dengan variasi waktu perendaman inhibitor dalam HCl terpanjang dan terpendek. Hasil pengujian mikroskop optik dan SEM menunjukkan bahwa semakin lama waktu perendaman dalam inhibitor maka morfologi permukaan baja semakin baik dengan lubang dan retakan yang semakin sedikit. Hasil XRD juga menunjukkan bahwa terdapat empat puncak tajam yang berarti bahwa sampel dengan laju korosi terendah menghasilkan fasa Fe dan C kristal akibat reaksi antara permukaan baja dengan inhibitor. Analisis kimia kuantum dengan metode DFT (Density Functional Theory) juga menghasilkan efisiensi inhibisi yang cukup tinggi dan mendekati hasil eksperimen sebesar 80,2098%
Core Reactivity Analysis during Fuel Draining Process in the Molten Salt Fast Reactor
Get PDFA study of the core criticality during the draining process of liquid fuel salt on Molten Salt Fast Reactor (MSFR) was done. Two accident scenario that causes the draining process were loss of freeze valve coolant and loss of secondary coolant. This study used basic design of the MSFR with the salt fuel compositions of LiF (77.5%) – ThF4 (19.985%) – 233UF4 (2.515%). The criticality calculation has been analyzed from the value of the effective multiplication factor obtained from Open MC (Monte Carlo base) calculation. The effective multiplication factor was calculated with a variation on the number of freeze valves open; 1, 8, and 16 valves. The calculation has resulted in the value of effective multiplication factor decreasing exponentially during the draining process. Results from this study could be used as basic for the future study of the accident condition in MSFR, since there are still many MSRs accident scenarios that still haven't been taken into account
Nanosilica Particulate Magnetic as Alternative Filler on Natural Rubber Composites with Human-Tissue-Like Mechanical Characteristic
Get PDFThere have been no reports of the simultaneous application of natural fillers, such as magnetite and natural zeolites, to increase the strength of composites containing silica (SiO2) fillers as reinforcing fillers in natural rubber. This study has investigated the effect of magnetically modified natural zeolite on nanosilica-reinforced natural rubber composites that include a mechanical characteristic like human tissue. We use technical specifications rubber (TSR) SIR 20 with nanosilica reinforced fillers and Titanate coupling agent (TCA) as fillers and elastomer binders. The results showed that the nanosilica-zeolite-magnetite (Fe3O4) mixture had an influence on strength and stiffness and could be a substitute filler. The precursors made with some variations include the optimization of filler and the optimization volume fraction of nanosilica. Mechanical characteristics of different human body part tissue were compared to the control samples and have similar mechanical characteristics with internal human tissue characteristic. Based on these results, nanosilica fillers combine with magnetically modified zeolites and titanate coupling agents, potentially as an alternative filler to replace carbon black, and are applicable for synthetic muscle replacement cadavers with a customized formula
English
No full textA study was performed comparing the performance of UO2 and (Th,U-233)O2 fuel in small long-life PWR. The neutronic calculation carried out by PIJ module of SRAC2006 was done to a fuel cell in 10 years of operation. The calculation was conducted by varying the enrichment of U-235 in UO2 and U-233 in (Th,U-233)O2 for 1% - 20% and also by varying the fuel volume fraction for 40%, 45%, 50%, 55%, and 60%. The performance was observed by comparing the enrichment needed by each fuel type to gain criticality in 10 years, the infinite multiplication factor (k-inf) value, and the conversion ratio (CR) value. The calculation results showed that 60% fuel volume fraction gave critical conditions with the lowest infinite multiplication factor and highest conversion ratio for both fuel types. While in terms of fissile nuclide enrichment needed, (Th,U-233)O2 had better performance than UO2, because only 5% U-233 was needed in (Th,U-233)O2 while UO2 needed 9% U-235 to gain criticality in 10 years of operation.Studi untuk membandingkan performa bahan bakar UO2 dan (Th,U-233)O2 pada PWR kecil berumur panjang telah dilakukan. Perhitungan neutronik dilakukan dengan menggunakan modul PIJ program SRAC2006 pada sebuah pin sel bahan bakar selama 10 tahun masa operasi. Perhitungan dilakukan dengan memvariasikan pengayaan U-235 dalam UO2 dan U-233 dalam (Th,U-233)O2 sebesar 1% - 20% dan dengan memvariasikan fraksi volume bahan bakar sebesar 40%, 45%, 50%, 55%, dan 60%. Performa bahan bakar diamati dengan membandingkan pengayaan yang dibutuhkan oleh tiap jenis bahan bakar untuk mencapai kritikalitas selama 10 tahun, nilai faktor multiplikasi infinit (k-inf), dan nilai rasio konversi (CR). Hasil perhitungan menunjukkan bahwa fraksi volume bahan bakar 60% menghasilkan kondisi kritis dengan nilai k-inf terendah dan nilai CR tertinggi pada kedua jenis bahan bakar. Berdasarkan jumlah pengayaan nuklida fisil yang dibutuhkan, (Th,U-233)O2 memiliki performa yang lebih baik dari UO2 karena hanya 5% U-233 yang dibutuhkan dalam (Th,U-233)O2, sedangkan UO2 membutuhkan 9% U-235 untuk memperoleh kritikalitas selama 10 tahun