scholarly journals Comparative Study of Four TiO2-Based Photocatalysts to Degrade 2,4-D in a Semi-Passive System

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 621 ◽  
Author(s):  
Gisoo Heydari ◽  
Jordan Hollman ◽  
Gopal Achari ◽  
Cooper Langford
Keyword(s):  
Energy Consumption ◽  
Degradation Rate ◽  
Light Emitting Diode ◽  
Three Dimensional ◽  
Dichlorophenoxyacetic Acid ◽  
Light Emitting ◽  
Glass Spheres ◽  
Degradation Rate Constant ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Mode Energy

In this study, the relative efficiency of four forms of supported titanium dioxide (TiO2) as a photocatalyst to degrade 2,4-dichlorophenoxyacetic acid (2,4-D) in Killex®, a commercially available herbicide was studied. Coated glass spheres, anodized plate, anodized mesh, and electro-photocatalysis using the anodized mesh were evaluated under an ultraviolet – light-emitting diode (UV-LED) light source at λ = 365 nm in a semi-passive mode. Energy consumption of the system was used to compare the efficiency of the photocatalysts. The results showed both photospheres and mesh consumed approximately 80 J/cm3 energy followed by electro-photocatalysis (112.2 J/cm3), and the anodized plate (114.5 J/cm3). Although electro-photocatalysis showed the fastest degradation rate (K = 5.04 mg L−1 h−1), its energy consumption was at the same level as the anodized plate with a lower degradation rate constant of 3.07 mg L−1 h−1. The results demonstrated that three-dimensional nanotubes of TiO2 surrounding the mesh provide superior degradation compared to one-dimensional arrays on the planar surface of the anodized plate. With limited broad-scale comparative studies between varieties of different TiO2 supports, this study provides a comparative analysis of relative degradation efficiencies between the four photocatalytic configurations.

A simple design of uniform LED illumination using catadioptric collimator and freeform lenslet array

2021 ◽  
pp. 147715352110524
Author(s):  
DT Vu ◽  
H Vu ◽  
S Shin ◽  
NM Kieu ◽  
TQ Tien ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Light Emitting Diode ◽  
Optical Path Length ◽  
Light Emitting ◽  
Simple Strategy ◽  
Area Of Interest ◽  
Lenslet Array ◽  
Freeform Optics ◽  
Receiver Plane ◽  
Indoor Lighting

We introduce a compact lenslet array principle that takes advantage of freeform optics to deploy a light distributor, beneficial for highly efficient, inexpensive, low energy consumption light-emitting diode (LED) lighting system. We outline here a simple strategy for designing the freeform lens that makes use of an array of the identical plano-convex lenslet. The light is redistributed from such lenslet, hinging on the principle of optical path length conservation, and then delivered to the receiver plane. The superimposing of such illumination area from every lenslet occurs on the receiver plane, in which the non-uniform illumination area located in the boundary should have the same dimension as the size of the freeform lenslet array. Such an area, insofar, is negligible due to their small size, which is the crux of our design, representing a large departure from the former implementations. Based on simulations that assess light performance, the proposed design exhibited the compatibility for multiple radiation geometries and off-axis lighting without concern for the initial radiation pattern of the source. As simulated, the LED light source integrated with such proposed freeform lenslet array revealed high luminous efficiency and uniformity within the illumination area of interest were above 70% and 85%, respectively. Such novel design was then experimentally demonstrated to possess a uniformity of 75% at hand, which was close to the simulation results. Also, proposed indoor lighting was implemented in comparison with the commercial LED downlight and LED panel, whereby the energy consumption, number of luminaires and illumination performance were assessed to show the advantage of our simplified model.

Nanorod Array Structure Through a Nanomolding Process for Semiconductor Lighting and Display Applications

NANO ◽  
2019 ◽  
Vol 14 (12) ◽  
pp. 1950153 ◽  
Author(s):  
Je Won Kim
Keyword(s):  
Light Emitting Diode ◽  
Three Dimensional ◽  
Nanorod Array ◽  
Dimensional Structure ◽  
Single Chip ◽  
Semiconductor Processing ◽  
Light Emitting ◽  
Multiple Wavelengths ◽  
Array Structure ◽  
Wavelength Control

Three-dimensional structure and growth can be more appropriately realized through a nanomanufacturing process that uses a mask patterning and etching process. Unlike conventional single-wavelength semiconductor lighting sources, the uniformity and reproducibility of the nanomolding process in this study enable multiple wavelengths to be used in lighting and display applications. This study shows the various wavelength characteristics through a newly developed nanomold and its nanorod array and also proves the feasibility of a white light without phosphors for emitting multiple wavelengths from a single chip. In this study, we proposed the possibility of wavelength control by fabricating a light-emitting diode with a three-dimensional nanostructure, using a nanomold with semiconductor processing.

Color three-dimensional display with omnidirectional view based on a light-emitting diode projector

2009 ◽  
Vol 48 (22) ◽  
pp. 4490 ◽  
Author(s):  
Caijie Yan ◽  
Xu Liu ◽  
Haifeng Li ◽  
Xinxing Xia ◽  
Haixia Lu ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Three Dimensional ◽  
Light Emitting ◽  
Three Dimensional Display

scholarly journals Electrodegradation of 2,4-dichlorophenoxyacetic acid herbicide from aqueous solution using three-dimensional electrode reactor with G/β-PbO2 anode: Taguchi optimization and degradation mechanism determination

RSC Advances ◽  
2018 ◽  
Vol 8 (69) ◽  
pp. 39256-39268 ◽  
Author(s):  
Abdollah Dargahi ◽  
Davood Nematollahi ◽  
Ghorban Asgari ◽  
Reza Shokoohi ◽  
Amin Ansari ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Degradation Mechanism ◽  
Three Dimensional ◽  
Dichlorophenoxyacetic Acid ◽  
Electrochemical Degradation ◽  
Taguchi Optimization ◽  
Optimization Of Process Parameters ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
2D And 3D ◽  
Pbo2 Anode

Optimization of process parameters using the Taguchi method, electrochemical degradation and electrochemical degradation mechanism of 2,4-D herbicide using 2D and 3D reactors with G/β-PbO2 anode were investigated.

Reflector designed for light-emitting-diode lighting source in three-dimensional space

Optik ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4534-4538 ◽  
Author(s):  
Guangzhen Wang ◽  
Yu Hou ◽  
Lichun Hu ◽  
Wanwei Tang ◽  
Jian Gao ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Light Emitting ◽  
Three Dimensional Space

Numerical Analysis for Thermal Performance of High Power Multi-Chip LED Packaging

2010 ◽  
Vol 139-141 ◽  
pp. 1433-1437
Author(s):  
Kai Lin Pan ◽  
Jiao Pin Wang ◽  
Jing Liu ◽  
Guo Tao Ren
Keyword(s):  
High Power ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Three Dimensional ◽  
Junction Temperature ◽  
Light Emitting ◽  
Die Attach ◽  
Dissipation Model ◽  
Key Issues

Heat dissipation and cost are the key issues for light-emitting diode (LED) packaging. In this paper, based on the thermal resistance network model of LED packaging, three-dimensional heat dissipation model of high power multi-chip LED packaging is developed and analyzed with the application of finite element method. Temperature distributions of the current multi-chip LED packaging model are investigated systematically under the different materials of the chip substrate, die attach, and/or different structures of the heat sink and fin. The results show that the junction temperature can be decreased effectively by increasing the height of the heat sink, the width of the fin, and the thermal conductivity of the chip substrate and die attach materials. The lower cost and higher reliability for LED source can be obtained through reasonable selection of materials and structure parameters of the LED lighting system.

High-efficiency vertical-structure GaN-based light-emitting diodes on Si substrates

2018 ◽  
Vol 6 (7) ◽  
pp. 1642-1650 ◽  
Author(s):  
Wenliang Wang ◽  
Yunhao Lin ◽  
Yuan Li ◽  
Xiaochan Li ◽  
Liegen Huang ◽  
...  
Keyword(s):  
High Efficiency ◽  
Light Emitting Diode ◽  
Three Dimensional ◽  
Chemical Vapor ◽  
Buffer Layers ◽  
Organic Chemical ◽  
Light Emitting ◽  
Si Substrates ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

High-quality GaN-based light-emitting diode (LED) wafers have been grown on Si substrates by metal–organic chemical vapor deposition by designing epitaxial structures with AlN/Al0.24Ga0.76N buffer layers and a three-dimensional (3D) GaN layer.

Three-Dimensional Mapping of Quantum Wells in a GaN/InGaN Core–Shell Nanowire Light-Emitting Diode Array

Nano Letters ◽  
2013 ◽  
Vol 13 (9) ◽  
pp. 4317-4325 ◽  
Author(s):  
James R. Riley ◽  
Sonal Padalkar ◽  
Qiming Li ◽  
Ping Lu ◽  
Daniel D. Koleske ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Light Emitting Diode ◽  
Three Dimensional ◽  
Diode Array ◽  
Core Shell ◽  
Light Emitting ◽  
Three Dimensional Mapping ◽  
Dimensional Mapping
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