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"An optical modulation by the use of bending effect developed from the effect of relative bending loss on optical fiber. The bending loss will decrease if the bending angle decreases. By varying the bending angle the bending loss will vary too. The modulation process obtained through this mechanism. The bending angle on optical fiber obtained from three mandrel laid on the loud-speaker; two mandrel on the frame and one on the cone of loud-speaker, while optical fiber laid between the mandrel. If current signal injected on coil loudspeaker, the coil will push the mandrel and then push optical fiber to form bending angle. The obtained 3 dB frequency response ranged from 28 Hz to 5714.3 Hz while the SNR and modulation index are 32.98 dB and 0.956 respectively. This modulator would be useable for single channel instrumentation and control links."

"An optical modulation using attenuated total reflection offers several advantages in terms of speed, aperture size, and ease of operation compared to other techniques for amplitude modulation of a collimated light beam. This study developed a simple device consists of a prism separated from a mirror reflecting surface by a small - size gap. Varying the gap thickness changes the intensity of the light reflected off by the base of the prism. This thesis devoted to a study on the coupling of a plane wave, the principle of operation and some experiments. The result leads to the realization of the simple device with a high performance."

"Disperse Red 1 (DR 1) adalah pewarna merah yang memiliki unsur kimia C16H18N4O3. DR 1 merupakan pewarna azo yang mempunyai sifat fotoisomerisasi reversibel. Pada pewarna azo perubahan dari trans ke cis dapat menyebabkan perubahan reversibel yang diinduksi cahaya pada beberapa pewarna, seperti DR 1. Perubahan struktur dari trans ke cis terjadi karena penyerapan cahaya ultraviolet (UV). Pada penelitian ini dilakukan dengan tujuan untuk mengetahui nilai spektrum serapan cahaya pada perubahan struktur molekul Disperse Red 1 isomer trans terhadap isomer 90° dan isomer cis, sehingga mengetahui besar pergeseran spektrum penyerapan cahaya karena penyerapan UV menggunakan metode komputasi density functional theory (DFT). Hasil analisa berdasarkan spektrum serapan optik didapatkan perubahan warna pada isomer trans, 90°, dan cis karena ketika trans menyerap sinar UV maka akan terjadi pergeseran molekul sehingga membentuk isomer 90° dan isomer cis, pada saat pergeseran inilah molekul menyerap energi cahaya sehingga mengalami perubahan warna.

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Disperse Red 1 (DR 1) is a red dye with the chemical element C16H18N4O3. DR 1 is an azo dye with reversible photoisomerisation properties. Some azo dyes, including DR 1, undergo light-induced reversible transitions from trans to cis. Changes in structure from trans to cis occur due to ultraviolet (UV) light absorption. This study aimed to determine the value of changes in the molecular structure of Disperse Red 1 trans isomer to 90° isomer and cis isomer, on the light absorption spectrum in order to determine the magnitude of the shift in the light absorption spectrum due to UV absorption using the density functional theory (DFT) computational method. Based on the optical absorption spectrum, the analysis revealed colour changes in the trans, 90 °, and cis isomers. When the trans-absorbed UV light, a molecular shift occurred to form the 90° isomer and the cis isomer. The molecule absorbed light energy during this shift, causing it to change colour."

"Tujuan penelitian ini adalah untuk mengetahui pengaruh jarak sumber sinar Light Emitting Diode (LED) terhadap kekuatan tarik diametral resin komposit bulk-fill. Resin komposit bulk-fill Tetric® N-Ceram Bulk-Fill, shade IVA (setara dengan warna VITA A2-A3) dibuat menjadi 30 spesimen berbentuk silinder dengan ukuran tebal 3 mm dan diameter 6 mm. Spesimen dibagi menjadi 3 kelompok variasi jarak penyinaran, yaitu 0 mm, 3 mm dan 5 mm. Penyinaran menggunakan LED Light Curing Unit Bluephase® Style (Ivoclar-Vivadent, Liechtenstein) dengan durasi penyinaran selama 10 detik sesuai instruksi pabrik. Data dianalisis secara statistik menggunakan metode ANOVA satu arah. Hasil analisis tidak menunjukkan perbedaan bermakna (p>0,05) pada semua kelompok. Jarak sumber sinar LED ≤ 5 mm tidak memberikan pengaruh yang signifikan terhadap kekuatan tarik diametral resin komposit bulk-fill.

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This study aimed to evaluate the effect of LED light source distance on diametral tensile strength of bulk-fill composite restorative material. Bulk-fill composite Tetric® N-Ceram Bulk-Fill, shade IVA (equal to VITA shade A2-A3) was formed into 30 cylindrical specimens with 3 mm in thickness and 6 mm in diameter. Specimens were divided into 3 groups with various curing distance: 0 mm, 3 mm and 5 mm. All groups were polymerized by LED Light Curing Unit Bluephase® Style (Ivoclar-Vivadent, Liechtenstein) for 10 seconds based on manufacturer’s instruction. Data were statistically analyzed by one-way ANOVA The result showed insignificant differences in all groups (p>0,05). LED light source distance ≤ 5 mm was not significantly affected the diametral tensile strength of bulk-fill composite."

"Organic Light Emitting Diode OLED adalah sebuah divais electroluminance yang menggunakan bahan organik sebagai emissive layer. Dalam fabrikasi OLED terdapat berbagai macam cara untuk menumbuhkan emissive layer dengan ketebalan tertentu. Salah satu tekniknya adalah dengan cara spincoating. Kecepatan rotasi spincoating menentukan ketebalan dari lapisan yang ditumbuhkan. Ketebalan lapisan tersebut mempengaruhi performa divais yang dihasilkan. Dalam skripsi ini OLED dengan struktur ITO/ Polylfluorene PFO /Al difabrikasi menggunakan teknik laminasi dan menggunakan spincoating untuk menumbuhkan lapisan PFO. Variasi dilakukan terhadap kecepatan rotasi spincoating pada 1000 rpm, 2000 rpm, 3000 rpm, 4000 rpm, dan 5000 rpm. Hasil fabrikasi menunjukkan karakteristik arus dan tegangan yang dihasilkan sesuai dengan karakteristik OLED. Kecepatan rotasi spincoating yang optimum adalah 3000 rpm. Divais 3000 rpm, 4000 rpm, dan 5000 rpm dapat menghasilkan luminasi berwarna kebiru-biruan.

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Organic Light Emitting Diode OLED is an electroluminance device that uses organic material as an emissive layer. In OLED fabrication there are various ways to grow an emissive layer with a certain thickness. One of the techniques is by spincoating. The rotation speed of spincoating determines the thickness of the grown layer. The thickness of the layer affects the performance of the resulting device. In this thesis OLED with the structure of ITO Polylfluorene PFO Al is fabricated using lamination technique and using spincoating to grow PFO. Variations were made to spincoating rotation speeds at 1000 rpm, 2000 rpm, 3000 rpm, 4000 rpm, and 5000 rpm. The fabrication results show the current characteristics and OLED voltage. The optimum rotational speed of spincoating at 3000 rpm. The device has the smallest treshold voltage. The 3000 rpm, 4000 rpm, and 5000 rpm devices can produce bluish luminations."

"Tujuan penelitian ini untuk mengetahui pengaruh penggunaan sumber sinar berbeda terhadap kekuatan tarik diametral resin komposit bulk-fill. Resin komposit bulk-fill Tetric N-Ceram Bulk Fill dibuat sebanyak 20 spesimen berbentuk lempeng dengan diameter 6 mm dan tebal 3 mm. Spesimen dibagi menjadi dua kelompok yaitu kelompok yang disinari dengan sumber sinar QTH dan sumber sinar LED. Uji kekuatan tarik diametral dilakukan dengan menggunakan Universal Testing Machine. Hasil penelitian menunjukkan nilai rerata kekuatan tarik diametral resin komposit bulk-fill yang disinari sumber sinar QTH dan LED sebesar 38.62 2.34 dan 42.02 3.21. Hasil uji independent sample T menunjukkan nilai rerata pada kedua kelompok berbeda bermakna.

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This study aimed to evaluate the effect of using different light sources on the diametral tensile strength of bulk fill resin composite. Bulk fill resin composite Tetric N Ceram Bulk Fill was used to make of 20 disc shape specimens with 6 mm in diameter and 3 mm in thickness. Specimens were divided into two groups, the two groups were polymerized with using QTH and LED light source curing unit. Diametral tensile strength test was conducted by using a Universal Testing Machine Shimadzu, Japan. The results showed that diametral tensile strength mean value of bulk fill resin composite that were cured with QTH and LED light source were 38.62 2.34 and 42.02 3.21 MPa respectively. Independent sample t test results showed that the mean value of the two groups was significantly different."