Artikel – Page 28 – All about Harutya

This paper summarizes ISRN’s 3-years research on the occurrence of dawn and dusk to mark the timings of the Fajr and Isha prayers. We acquired the astronomical data not only in Indonesia but also in Malaysia, the US, Egypt, and Turkey. It will be an attempt to compile a global twilight pattern in the future. The main instrument used is a Sky Quality Meter (SQM) that records the sky brightness data. For quality assurance, ISRN-UHAMKA employed dozens of imaging sensors ranging from an All Sky Camera, different types of DSLR, and gadget cameras. From hundreds of astronomical data, we have collected; it seems that the occurrence of the real twilight to mark the Fajr prayer throughout the world is the same. That is when the sun is at its depression angle of around 120-130. Likewise, the dusk to mark the end of the Maghrib prayer also occurs when the sun is at a solar depression angle around 120-130. Meanwhile, Muslims in the world use different solar depression angles ranging from -150 to 200 fields.

http://repository.uhamka.ac.id/id/eprint/17224/1/Towards%20the%20Compilation%20of%20the%20Global%20Twilight%20Pattern.pdf

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SINTESIS ARANG BATOK KELAPA MENJADI MATERIAL MAJU GRAFEN MENGGUNAKAN METODE REDUKSI KIMIA

Post author By Admin Harutya
Post date December 12, 2022
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http://repository.uhamka.ac.id/id/eprint/17223/

SINTESIS ARANG BATOK KELAPA MENJADI MATERIAL MAJU GRAFEN MENGGUNAKAN METODE REDUKSI KIMIA

Ramza, Harry

Penelitian ini merupakan bentuk kajian sederhana yang memanfaatkan biomassa pertanian yaitu batok kelapa yang disintesis menjadi material maju grafen. Grafen merupakan salah satu material maju dan terbarukan dalam bidang sains dan teknologi terkini karena kemanfaatannya yang multifungsi. Penelitian ini diawali dengan mengubah biomassa batok kelapa menjadi karbon melalui suatu reaksi pembakaran. Arang hasil dari pembakaran selanjutnya diberikan perlakuan dengan metode reduksi kimia atau metode Hummer tereduksi. Hasil penelitian ini memperlihatkan bentuk morfologi grafen berupa serpihan-serpihan atau dikenal dengan istilah grafen Flakes. Hasil ini terkonfirmasi melalui uji visualisasi SEM, dimana grafen Flakes diperlihatkan dalam formasi tumpukan mengindikasikan struktur multilayer. Hasil uji TEM memperlihatkan jarak antar kisi kristal yang dimilikinya yaitu berkisar pada 2,40 dan 2,46 Å. Berdasarkan pada data jarak antar kisi kristal tersebut, hasil simulasi energi menggunakan prinsip DOS didapatkan bahwan grafen hasil sintesis memiliki energi secara berturut-turut adalah 4,0 eV untuk level konduksi dan 3,3 eV untuk level valensi. Hasil uji optik sifat absorbansi dan fluoresens memperlihatkan grafen memiliki dua puncak serapan utama yang berkorelasi dengan terjadinya transisi energi pi-to-pi dan n − pi∗ dari bentuk ikatan C=C dan C-O-C. Adapun pendaran yang dihasilkan melalui uji fluoresensi adalah warna hijau dengan panjang gelombang 525 nm. Secara sederhanaran cangan penelitian dapat dikatakan telah berhasil dalam mensintesis grafen dari arang batok kelapa, meskipun belum sempurna dan masih perlu untuk dilakukan kajian kembali. Hasil dari penelitian ini selanjutnya akan dikembangkan lagi menjadi bentuk grafen dengan morfologi yang berpori.

http://repository.uhamka.ac.id/id/eprint/17223/1/Sintesis%20Arang%20Batok%20Kelapa%20menjadi%20Material%20Maju%20GrafenMenggunakan%20Metode%20Reduksi%20Kimia.pdf

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The Comparison of Experimental and Analytical Study of the Gaussian Intensity Distribution for Light Emitting Diodes Beam

http://repository.uhamka.ac.id/id/eprint/17222/

The Comparison of Experimental and Analytical Study of the Gaussian Intensity Distribution for Light Emitting Diodes Beam

Ramza, Harry

Problem statement: Wireless communication using white Light Emitting Diodes (LEDs) is the latest research field for next-generation communication. This study studies the comparison of Gaussian intensity distribution of the white LED using experimental and analytical method. The white
LEDs are conducted to transmit an audio signal to the receiver. The receiver circuit consist of solar cell connected to the speaker to recover the audio signal. From the comparison of experimental and analytical data, the Gaussian plot of experimental data is steeper than the analytical data, meaning that the LED has small-divergence beam. Conclusion/Recommendations: The output voltage of experimental works decrease exponentially with the distance whiles the Full Width Half Maximum (FWHM) value increase exponentially with the distance. The gradual increment and decrement of the analytical signal can be applicable to visible light communication implementation as such light source can cover wide area for signal transmission.

http://repository.uhamka.ac.id/id/eprint/17222/1/11-The_Comparison_of_Experimental_and_Analytical%20Study%20of%20the%20Gaussian%20IntensityDistribution%20for%20Light%20Emitting%20Diodes%20Beam.pdf

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Optical System Monitoring Based on Reflection Spectrum of Fiber Bragg Grating

Post author By Admin Harutya
Post date December 12, 2022
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http://repository.uhamka.ac.id/id/eprint/17221/

Optical System Monitoring Based on Reflection Spectrum of Fiber Bragg Grating

Ramza, Harry

Abstract: Problem statement: This study presents fiber fault monitoring approaches for Fiber-to-the Home (FTTH) with a Passive Optical Network (PON). Current fiber fault monitoring approaches are difficult to be implemented due to its complexity and high loss as the amount of branches increase.
Approach: A fiber fault monitoring scheme is proposed whereas Fiber Bragg Grating (FBG) is placed on each branch of the Optical Network Unit (ONU). The advantages of the scheme are that it is simple, low cost and efficient in monitoring fiber fault in ONU. FTTH based network design is simulated using Optisystemtem 8.0 in order to investigate the feasibility of the proposed scheme. Results: The reflection spectrum of Fiber Bragg Gratings (FBGs) with different spectrum shape, frequencies and amplitude is used to differentiate each optical network. The simulation result shows that the unique characteristic of fiber Bragg grating is able to distinguish each optical network for a 20 km Passive Optical Network (PON) system. Conclusion: This study suggests the implementation of Fiber Bragg Grating that is placed in each network instead of using Optical Time Domain Reflectometer (OTDR) for fiber fault monitoring.

http://repository.uhamka.ac.id/id/eprint/17221/1/10-Optical%20System%20Monitoring%20Based%20on%20reflection%20spectrum%20of%20Fiber%20Bragg%20Grating.pdf

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Optical Sensing Performance of Multimode Polymer Optical Fiber (POF) Coated with ZnO towards Methanol Vapour

Post author By Admin Harutya
Post date December 12, 2022
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http://repository.uhamka.ac.id/id/eprint/17220/

Optical Sensing Performance of Multimode Polymer Optical Fiber (POF) Coated with ZnO towards Methanol Vapour

Ramza, Harry

In this work, optical sensing performance of multimode polymer optical fiber coated with ZnO towards methanol vapour with different concentrations is studied. The etching process of the POF was carried out using chemical etching method. ZnO was synthesized with sol-gel method to obtain the sensitive material coating. The etched optical fiber was then dipcoated with ZnO and dried at 70oC to enhance the binding of the materials and to remove organic residue. Scanning Electron Microscope (SEM), and X-Ray poer Difraction (XRD)analyses were performed to characterize the ZnO layer. The measurements of optical performance were taken using a spectrophotometer in the optical wavelength in the range of 500–8000nm. The absorbance response of the ZnO coated etched fiber reduced proportionally, upon exposure to methanol vapour with concentration in the range of 5%–5

http://repository.uhamka.ac.id/id/eprint/17220/1/9-Optical%20Sensing%20Performance%20of%20Multimode%20Polymer%20Optical%20Fiber%20%28POF%29%20Coated%20with%20ZnO.pdf

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Modeling and Optimization of Fiber Optic Chemical Vapor Sensor

Post author By Admin Harutya
Post date December 12, 2022
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http://repository.uhamka.ac.id/id/eprint/17219/

Modeling and Optimization of Fiber Optic Chemical Vapor Sensor

Ramza, Harry

This paper discusses the application of Box–Behnken Design (BBD) to get a mathematical model for chemical vapor liquid detection with the objective of optimizing the optical fiber optic sensor probe. The parameters of input process were considered as variables to create the output parameters (response) using Response Surface Methodology (RSM). Input parameters such as length of probe, diameter of probe, photo-initiator liquid, vacuum pressure of chamber and purity of liquid detector were processed with Box – Behnken design approach for making POF (plastic optical fiber) probe of chemical sensor. Design Expert software was used to design the experiments with randomized runs. The main aim is to create an equation model as a platform for the probe design of POF chemical vapors detection similar to acetone, ethanol and methanol liquid. The experimental data were processed by considering the input parameters. The contribution of this research is the mathematic equation model that applies the polynomial equation. The final result of the wavelength application was between five to be three wavelengths, 434.05 nm, 486.13 nm and 656.03 nm. These wavelengths are the significant result of optimization measured using three chemical vapors. The optimization process uses the analysis of variables (ANOVA) to produce the quadratic model equation.

http://repository.uhamka.ac.id/id/eprint/17219/1/7-Modeling%20and%20Optimization%20of%20Fiber%20Optic%20Chemical%20Vapor%20Sensor.pdf

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