Green LED Light Research Articles

Computer-Guided Discovery of a pH-Responsive Organic Photocatalyst and Application for pH and Light Dual-Gated Polymerization.

In this work, we adopted a fully computer-guided strategy in discovering an efficient pH-switchable organic photocatalyst (OPC), unprecedentedly turning colorless at pH 5 and recovering strong visible-light absorption and photoactivity at pH 7. This is the first example of an OPC design fully guided by comprehensive density functional theory (DFT) studies covering electrostatic, electrochemical, and photophysical predictions. Characterization of the designed OPC after synthesis confirmed the computational predictions. We applied this OPC to mediate an aqueous photoinduced electron/energy transfer-reversible addition-fragmentation chain transfer (PET-RAFT) polymerization under green LED light (nominal emission wavelength: 530 nm, 5 mW/cm2). We demonstrated that the polymerization can be reversibly ceased by a slight change of pH (pH ≤ 5.0) or in the absence of light. Furthermore, we demonstrated that the polymerization rate could be significantly retarded by bubbling carbon dioxide into the reaction solution under visible light. Conversely, the rate could be fully recovered via exposure to nitrogen gas. This is the first example of a pH and light dual-gated polymerization system with complete and reversible inhibition.

Rewritable Optical Patterns in Light-Responsive Ultrahigh Molecular Weight Polyethylene

Spiropyran is used as a photochromic dye to create colored patterns in highly drawn ultrahigh molecular weight polyethylene (UHMW PE) films. The dye is incorporated in highly crystalline, drawn UHMW PE tapes and fibers and isomerizes to its merocyanine state upon UV light irradiation, resulting in a color change from transparent to purple. The isomerization from merocyanine to spiropyran to erase the color can be simply induced by using heat or a green LED light. The combination of the use of a mask and the reversibility of the isomerization results in colored patterns that can be written, erased, and rewritten using UV light and heat or green LED light.

Design and development of smart fishing poles using ICT enabled systems

Compared with the existing fish poles' products, this intelligent float can fish at night because it has the night light. When the floats are put into the river, lake or the sea, the green LED light will flash and be recognised. This fish pole can make fish more accurate. It has the accelerometer sensor. When the float is pulled by the fish in the water suddenly, the acceleration generates. It makes the light turn into the red. It prompts there are fish on a hook. When the fish bites food on hooks, the line triggers the infrared sensor. And the SMS which content is 'get fish' will send to the intelligent telephone. It tells people to take up the rod line. The Bluetooth module is linked with the floats. The shocked float triggers the infrared sensor and the buzzer works to remind the angler.

Long-term wear of dual mobility total hip replacement cups: explant study.

Dual mobility THA implantations are increasing. THA survival of more than 15years is considered long-term survival based on the Charnley prosthesis, which has a median wear rate of 39 to 98mm3/year. What is the median wear rate of dual mobility THA cups and its repartition on the liner volume? What are the factors influencing dual mobility wear? Thirty-five explants were analysed. The liners were entirely mapped with a fully automatic stripe light scanner that uses green LED light. The liners had a median wear rate of 38mm3/year. The distribution of the wear between the two bearings varied greatly. No factor was found influencing wear volumes. The median annual wear of dual mobility liners is at least as low as the wear of cemented polyethylene liners and lower than equivalent cementless liners. The two articulations of the dual mobility THA do not cause more wear. Level IV - case series.

Multiple switching light sources based motion artifacts reduction in reflectance photoplethysmography.

We proposed a technique to eliminate motion artifacts by subtracting the two green signals with different light intensity from single green LED. We used green LED light source with a photodetector to obtain the PPG signals from the wrist. We showed that the signal subtraction with different light intensity from the same light source reduced motion artifacts, and the clean PPG signal was remained. Performance comparison was carried out in five different scenarios: stationary state, fingers movement, gripping, up-down vertically bending and left-right horizontally swinging conditions. As expected, we obtained suitable clean PPG signals in all conditions using our proposed technique.

AUV docking experiments based on vision positioning using two cameras

An AUV(Autonomous Underwater Vehicle) docking test got finished successfully in the general deep water pool lab of Harbin Engineering University. Two major problems got solved. One is reliable underwater navigation method providing accurate relative position information, which is basically needed while AUV approaching. Four green LED lights are fixed around the station and two cameras are installed in AUV’s head part. A reliable vision positioning method using two cameras is adopted. Core algorithm switches between combining monocular and binocular positioning method according to the number of image in both cameras.. The other problem is that control system should be designed suited to the docking procedure, that is to say, outputs of controller ensures the declining of deviation between AUV position and center line of dock station. A two-layer control system is adopted considering the underactuated feature of our test bed. The guidance controller is designed based on Lyapunov stability theory. It outputs reference heading and trimming angle according to position deviations in horizontal and vertical plane respectively. Control parameters are adaptively adjusted by fuzzy algorithm. The execution controller eliminates errors of attitude angle employing an adaptively S-surface non-linear function. Pool test demonstrates that the navigating and control system works well. The system guarantees successful docking rate greater than 80%.

Study on the interaction of Fe(III) complex of BODIPY appended di(picolyl)amine with water and HeLa cells

The iron complex [(m-BDA)FeCl3] (Fe1) (m-BDA=8-[di(2-picolyl)amine-3-benzyl]-4,4-difluoro-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene) was characterized by spectroscopic methods. The emission intensity of Fe1 is weaker than that of m-BDA due to the electrostatic interaction between the Fe(III) ion and m-BDA. However, the coordination of water with the central Fe(III) ion in Fe1 changed metal–ligand charge transfer, thus the quenched emission at 509nm was recovered. Furthermore, Fe1 can catalyze water oxidation to generate dioxygen when irradiated by green LED light (10W). In particular, the Fe1 can enter into HepG-2 cells and show different inhibition rates in black and under irradiation. The anticancer activity of Fe1 was greatly enhanced under irradiation. Our results demonstrate that Fe(III) complexes of BODIPY can be developed as new kinds of photodynamic agents.

非相干LED光源产生高阶Bessel光束

The ideal high order Bessel beams was generated by monochromatic green LED light source for the first time. A novel method using cross-spectral density function and superposition of multi-wavelength was proposed to calculate the intensity distribution of light field emitted from the green LED then through the spiral phase plate and the axicon. And the cross-section intensity distribution along the optical axis based on this method was simulated. An experimental facility was designed to demonstrate the theory. The result showed that the high order Bessel beams could be obtained from the green LED light source by using the aperture to improve the spatial coherence of the light field emitted from the green LED. The cross-section intensity distribution of the experimental result, the size of the center dark spot and the non-diffraction distance were accorded well with the theoretical simulation and calculation. The research result offered the theoretical and experimental basis for the micromanipulation of particles by using incoherent light.

Kinetic study of acetaminophen degradation by visible light photocatalysis

In this work, a novel photocatalyst K3[Fe(CN)6]/TiO2 synthesized via a simple sol‐gel method was utilized to degrade acetaminophen (ACT) under visible light with the use of blue and green LED lights. Parameters (medium pH, initial concentration of reactant, catalyst concentration, temperature, and number of blue LED lights) affecting photocatalytic degradation of ACT were also investigated. The experimental result showed that compared to commercially available Degussa P‐25 (DP‐25) photocatalyst, K3[Fe(CN)6]/TiO2 gave higher degradation efficiency and rate constant (kapp) of ACT. The degradation efficiency or kapp decreased with increasing initial ACT concentration and temperature, but increased with increased number of blue LED lamps. Additionally, kapp increased as initial pH was increased from 5.6 to 6.9, but decreased at a high alkaline condition (pH 8.3). Furthermore, the degradation efficiency and kapp of ACT increased as K3[Fe(CN)6]/TiO2 loading was increased to 1 g L−1 but decreased and eventually leveled off at photocatalyst loading above this value. Photocatalytic degradation of ACT in K3[Fe(CN)6]/TiO2 catalyst system follows a pseudo–first‐order kinetics. The Langmuir–Hinshelwood equation was also satisfactorily used to model the degradation of ACT in K3[Fe(CN)6]/TiO2 catalyst system indicated by a satisfactory linear correlation between 1/kapp and Co, with kini = 6.54 × 10−4 mM/min and KACT = 17.27 mM−1.

Exposure Light Wavelength Effects on Charge Trapping and Detrapping of nc-MoOx Embedded ZrHfO High-k Stack

ABSTRACTThe influence of the red and green LED light exposure on the memory function of the nanocrystalline MoOx embedded ZrHfO high-k gate dielectric has been investigated. Since the performance of the device is mainly dependent on the hole trapping and detrapping mechanisms, the light exposure affects the hole generation, transfer, and storage to and in the dielectric structure. Both the charge storage capacity and the leakage current were increased from the light exposure. The Coulomb blockade phenomenon in the leakage current density vs. gate voltage curve disappears under the light exposure condition. The light exposure effect is potentially important for practical application of the device.

The Research of LED Lights Model Based on Road Lighting in Mesopic Vision

This paper analyzes the structural features of the human eye in the middle of the road lighting visual state of the visual request of road lighting in the Mesopic range of lighting, road lighting standards to build a white and green LED light source distribution model and defines the sharpness of the image according to the model function. In the Matlab7.1 environment, high pressure sodium yellow light LED white light and LED white and green background light, the model simulation analysis of the image clarity, results show that, in the Mesopic same brightness level state road lighting selection white and green the LED light source has better clarity and sensitivity.

Entrainment of the Two-Peak Circadian Rhythm of Trigonoscelis gigas Reitter (Coleoptera: Tenebrionidae) with non-24-hr Zeitgebers

Circadian rhythms of locomotor activity of the desert beetles T.gigas were entrained with skeleton photoperiods (2x2 hr per circadian cycle 30 lx green LED light pulses). The Zeitgeber period was stepwise reduced by 1 hr down to 22 hr or increased up to 26 hr. Within the range of entrainment, the phase angle Ψ of a circadian rhythm with respect to light depends upon the period of Zeitgeber differently for the morning (M) and evening (E) peak: M is easier to advance, while E is easier to delay. Beyond the range of entrainment both peaks became free-running with some relative coordination. Masking (direct stimulation of activity by light) occurred only during the subjective night, and never in subjective day. In few cases one of two peaks became free-running while its counterpart remained entrained, suggesting that each of the two peaks has its own visual input and can be entrained by light. These results are in agreement with the difference in the PRC shape for the M and E peaks, and support the hypothesis that M and E peaks are controlled by two functionally separate oscillators that have polar different properties, and are extremely strongly mutually coupled with phases locked at about 180°.