scholarly journals Multi-color broadband visible light source via GaN hexagonal annular structure

2014 ◽  
Vol 4 (1) ◽  
Author(s):  
Young-Ho Ko ◽  
Jie Song ◽  
Benjamin Leung ◽  
Jung Han ◽  
Yong-Hoon Cho
Keyword(s):  
Visible Light ◽  
Light Source ◽  
Annular Structure

Uniform-intensity, visible light source for in situ imaging

2009 ◽  
Vol 14 (2) ◽  
pp. 024024 ◽  
Author(s):  
Eyal Bar-Kochba ◽  
Saagar Govil ◽  
Jon P. Longtin ◽  
Andrew Gouldstone ◽  
Mary D. Frame
Keyword(s):  
Visible Light ◽  
Light Source ◽  
In Situ Imaging

Bioinspired micro/nanomotor with visible light energy–dependent forward, reverse, reciprocating, and spinning schooling motion

2021 ◽  
Vol 118 (42) ◽  
pp. e2104481118
Author(s):  
Jintao Tong ◽  
Dalei Wang ◽  
Ye Liu ◽  
Xin Lou ◽  
Jiwei Jiang ◽  
...  
Keyword(s):  
Visible Light ◽  
Light Source ◽  
Carbon Nitride ◽  
Free Carbon ◽  
Light Energy ◽  
Negative Phototaxis ◽  
Schooling Behavior ◽  
Low Illumination ◽  
Energy Dependent ◽  
High Irradiation

In nature, microorganisms could sense the intensity of the incident visible light and exhibit bidirectional (positive or negative) phototaxis. However, it is still challenging to achieve the similar biomimetic phototaxis for the artificial micro/nanomotor (MNM) counterparts with the size from a few nanometers to a few micrometers. In this work, we report a fuel-free carbon nitride (C3N4)/polypyrrole nanoparticle (PPyNP)-based smart MNM operating in water, whose behavior resembles that of the phototactic microorganism. The MNM moves toward the visible light source under low illumination and away from it under high irradiation, which relies on the competitive interplay between the light-induced self-diffusiophoresis and self-thermophoresis mechanisms concurrently integrated into the MNM. Interestingly, the competition between these two mechanisms leads to a collective bidirectional phototaxis of an ensemble of MNMs under uniform illuminations and a spinning schooling behavior under a nonuniform light, both of which can be finely controllable by visible light energy. Our results provide important insights into the design of the artificial counterpart of the phototactic microorganism with sophisticated motion behaviors for diverse applications.

scholarly journals UJI KEKERASAN RESIN KOMPOSIT AKTIVASI SINAR DENGAN BERBAGAI JARAK PENYINARAN

e-GIGI ◽  
2015 ◽  
Vol 3 (2) ◽  
Author(s):  
Jimmy Allorerung ◽  
P. S. Anindita ◽  
Paulina N. Gunawan
Keyword(s):  
Visible Light ◽  
Light Source ◽  
Vickers Hardness ◽  
Sampling Method ◽  
Composite Resin ◽  
Composite Surface ◽  
Purposive Sampling ◽  
Hardness Tester ◽  
Post Test ◽  
Nanohybrid Composite

Abstract: Composite resin is a dental material which is used to fix the caries teeth because it have good esthetic and hardness. Visible light cured (VLC) composite resin hac better polymerization than chemical reaction composite resin. However, it does not have any abutment, therefore, the distance between light source and the composite surface is mostly ignored by the operator. Lightning process is very important to obtained good polymerization, so that the composite has enough hardness to hold back human masticate pressure. Composite which does not have enough hardness will be easily cracked. This study aimed to find out the correct distance of polymerization so that the composite resin has enough hardness to hold back human masticate pressure. This study used a post-test only design group and was conducted at the Laboratory of Metalurgy University of Sam Ratulangi. There were 27 samples of nanohybrid composite resin obtained by using a purposive sampling method. The measurement used was the Vickers method and micro Vickers hardness tester. The results showed that the group that had the highest hardness value was the first group with a lightning distance of 0 mm or light source touching composite resin surface, the value of hardness was 841.49 N/mm2. This value step by step decreased because the lightning distance increased, so that the lowest hardness value is 290,95 N/mm2 which on ninth group. Conclusion: The lightning distance of nanohybrid composite resin which could hold back the maximum human masticate pressure was on distance 0-6 mm.Keyword : distance of lightning, nanohybrid composite resin, hardness value.Abstrak: Resin komposit merupakan bahan tumpatan yang sering digunakan dalam kedokteran gigi karena memiliki nilai estetis serta kekerasan yang baik. Resin komposit aktivasi sinar berpolimerisasi lebih baik daripada resin komposit aktivasi kimia, tetapi alat visible light cured (VLC) yang digunakan tidak memiliki dudukan sehingga jarak antara sumber sinar dengan permukaan komposit saat penyinaran sering diabaikan. Proses penyinaran sangat penting agar terjadi polimerisasi yang baik sehingga komposit memiliki kekerasan yang cukup untuk menahan tekanan kunyah manusia. Kekerasan yang tidak cukup dapat menyebabkan komposit mengalami cracking atau pecahnya tumpatan didalam mulut. Tujuan penelitian ini untuk mengetahui jarak penyinaran yang tepat agar resin komposit memiliki kekerasan yang cukup untuk menahan tekanan kunyah manusia. Metode penelitian yang digunakan adalah metode post-test only design group yang diukur pada resin komposit jenis nanohibrid dan dilakukan di Laboratorium Metalurgi Jurusan Teknik Mesin Universitas Sam Ratulangi, dengan sampel sebanyak 27 sampel. Pengambilan sampel dilakukan dengan metode purposive sampling dan pengukuran kekerasan komposit menggunakan metode Vickers dan alat micro vickers hardness tester. Hasil penelitian menunjukan bahwa kelompok yang memiliki nilai kekerasan tertinggi terdapat pada kelompok pertama dengan jarak penyinaran 0 mm atau sumber sinar menyentuh permukaan komposit dengan nilai kekerasan 841,49 N/mm2. Nilai kekerasan ini secara bertahap menurun seiring dengan bertambah jauh jarak penyinaran, sehingga nilai kekerasan paling rendah terdapat pada kelompok penyinaran 8 mm yaitu 230,95 N/mm2. Kesimpulan dari penelitian ini yaitu jarak penyinaran terhadap resin komposit jenis nanohibrid sehingga resin komposit memiliki kekerasan yang cukup untuk menahan tekanan kunyah maksimal manusia berkisar pada jarak 0-6 mm.Kata kunci : jarak penyinaran, resin komposit nanohibrid, nilai kekerasan

scholarly journals The Influence of LightPath Length on the Color of Flame-Fusion Synthetic Ruby

2021 ◽  
Author(s):  
Bin Yuan ◽  
Ying Guo ◽  
Ziyuan Liu
Keyword(s):  
Visible Light ◽  
Light Source ◽  
Path Length ◽  
Color Difference ◽  
Light Path ◽  
Light Spectrum ◽  
Strong Absorption Band ◽  
Vis Spectroscopy ◽  
Path Lengths ◽  
New Perspective

Abstract Colorimetric studies of different light path lengths from a new perspective of UV-Vis spectroscopy. The corrected ultraviolet-visible light spectrum was used to calculate the color of flame-fusion synthetic ruby, and the influence of light path length and standard light source on the color of flame-fusion synthetic ruby was studied. The results show that the L*, C*, h° under the A light source are higher than those under the D65 light source. In the ultraviolet-visible light spectrum, the strong absorption band of Cr3+ at 545nm is the main cause of the color of the ruby. As the length of the light path increases, the absorption peak area at 545nm also increases, the lightness L* decreases, and the hue angle h° increases. The chroma C* first increases as the length of the light path increases, and then begins to decrease under the influence of the continuous decrease in lightness. The color difference ΔE*ab reaches the maximum when the light path length is around 10mm, and the standard light source has the greatest influence on the color difference ΔE*ab. As the length of the light path continues to increase, the influence of the standard light source on the color difference\(\)ΔE*ab decreases.

Design and Simulation of light Source Layout of Indoor Visible Light Communication System

2021 ◽  
Author(s):  
Chenglong Dou ◽  
Chunyue Wang ◽  
Tianze Mi ◽  
Ziyi Zhang ◽  
Jin Yang ◽  
...  
Keyword(s):  
Visible Light ◽  
Light Source ◽  
Communication System ◽  
Visible Light Communication
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