scholarly journals Efficient Photocatalytic CO2 Reduction with MIL-100(Fe)-CsPbBr3 Composites

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1352
Author(s):  
Ruolin Cheng ◽  
Elke Debroye ◽  
Johan Hofkens ◽  
Maarten B. J. Roeffaers
Keyword(s):  
Performance Optimization ◽  
Photocatalytic Performance ◽  
Red Light ◽  
Green Light ◽  
Co2 Reduction ◽  
Light Response ◽  
High Specific Surface Area ◽  
Composite Photocatalysts ◽  
Halide Perovskites ◽  
Carrier Separation

Bromide-based metal halide perovskites (MHPs) are promising photocatalysts with strong blue-green light absorption. Composite photocatalysts of MHPs with MIL-100(Fe), as a powerful photocatalyst itself, have been investigated to extend the responsiveness towards red light. The composites, with a high specific surface area, display an enhanced solar light response, and the improved charge carrier separation in the heterojunctions is employed to maximize the photocatalytic performance. Optimization of the relative composition, with the formation of a dual-phase CsPbBr3 to CsPb2Br5 perovskite composite, shows an excellent photocatalytic performance with 20.4 μmol CO produced per gram of photocatalyst during one hour of visible light irradiation.

Modification of BiOCl Nanosheets with Bi2O3 Nanoparticles by a Facile Two Step Method and the Enhanced Photocatalytic Performance of the Composites

2017 ◽  
Vol 46 ◽  
pp. 203-211 ◽  
Author(s):  
Zhan Kui Cui ◽  
Er Kang Hu ◽  
Sen Lin Li
Keyword(s):  
Reaction Rate ◽  
Photocatalytic Performance ◽  
Light Response ◽  
Step Method ◽  
Response Range ◽  
Composite Photocatalysts ◽  
Photocatalytic Activities ◽  
Carrier Separation ◽  
Improved Performance

Bi2O3/BiOCl composite photocatalysts were produced by a facile two step method, including ultrasonically modifying BiOCl nanosheets with Bi nanoparticles first and the subsequent in situ thermal oxidation process. The samples were characterized by XRD, SEM, UV-vis and photoluminescence techniques. The photocatalytic activities were evaluated by photodegrading Rhodamine B under Xe light irradiation. The abilities of generating hydroxyl radicals during photocatalysis were tested by fluorescence method. The results show that Bi2O3 NPs were randomly distributed on the surface of BiOCl nanosheets. The photocatalytic efficiency was enhanced after modification and the best photocatalytic activity was obtained when the mole ratio of Bi2O3 to BiOCl was 0.24. The corresponding photochemical reaction rate of Bi2O3/BiOCl was 7 times that of BiOCl nanosheets and 5 times that of Bi2O3 nanoparticles. The improved performance of the composites was considered to associate with the extended light response range and the promoted charge carrier separation.

Effects of excitatory amino acids and their antagonists on the light response of luminosity and color-opponent horizontal cells in the turtle (Pseudemys scripta elegans) retina

1991 ◽  
Vol 6 (2) ◽  
pp. 135-149 ◽  
Author(s):  
Thomas J. Millar ◽  
Philip J. Anderton
Keyword(s):  
Amino Acids ◽  
Excitatory Amino Acids ◽  
Red Light ◽  
Green Light ◽  
Nmda Antagonist ◽  
Light Response ◽  
Excitatory Input ◽  
Horizontal Cells ◽  
Mk 801 ◽  
Normal Polarity

AbstractBoth kainic acid (KA) and N-methyl-d-aspartatic acid (NMDA) depolarize luminosity-type horizontal cells (L-type H cells) in normal turtle retina. The presence of both NMDA and non-NMDA receptors for excitatory amino acids (EAAs) on these cells was highlighted by an unusual effect of the noncompetitive NMDA-antagonist, MK-801. In retinas that had been exposed to MK-801, the action of NMDA was irreversibly altered to one of hyperpolarization, while the depolarizing effect of KA was unaltered. The aim of the present study was to further characterize these receptors on L-type H cells and to extend the investigation to color-opponent H cells (C-type H cells). Intracellular recording was used to study the effects of KA, NMDA, MK-801, the competitive NMDA antagonists, 2-amino-5-phosphonopentanoic acid (AP5) and 2-amino-7-phosphonoheptanoic acid (AP7), and the nonspecific EAA antagonist, kynurenic acid (KYN) on the light responses of L-type and C-type H cells in turtle retina. The effects of combinations of these drugs were also studied. In L-type H cells the agonists caused depolarization and loss of light response, KYN caused hyperpolarization and loss of light response, and MK-801, AP5 or AP7 had no direct effect. However, application of NMDA following MK-801, AP5 or AP7, but not KYN, caused hyperpolarization and loss of light response. The depolarizing effect of KA was unaltered by these antagonists. These data confirm the presence of an unusual NMDA receptor on L-type H cells. In the case of red\green C-type H cells, application of KA caused loss of responses to both red and green light, with loss of green responses preceding loss of red responses. NMDA initially removed responses to both red and green light. The most striking effect of NMDA was seen during early washout where the responses to red were reversed (hyperpolarizing). These responses eventually recovered their normal polarity. These results suggest that the depolarizing response of C-type H cells to red light is mediated by L-type H cells, but not via inhibition of the excitatory input from green cones to C-type H cells.

scholarly journals Blue/green light-responsive cyanobacteriochromes are cell shade sensors in red-light replete niches

2019 ◽  
Author(s):  
Gen Enomoto ◽  
Masahiko Ikeuchi
Keyword(s):  
Cell Density ◽  
Blue Light ◽  
Hot Springs ◽  
Incident Light ◽  
Natural Habitat ◽  
Red Light ◽  
Green Light ◽  
Light Response ◽  
Cell Aggregation ◽  
Cell Position

SummaryPhotoautotrophic cyanobacteria have developed sophisticated light response systems to capture and utilize the energy and information of incident light [1]. Cyanobacteria-specific photoreceptors cyanobacteriochromes (CBCRs) are distantly related to more widespread phytochromes. CBCRs show the most diverse spectral properties among the naturally occurring photoreceptors, typified by a unique and prevailing blue/green light-absorbing variant [2–6]. However, where the CBCR-mediated ‘colorful’ signaling systems function in nature has been elusive. We previously reported that the three CBCRs SesA/B/C synthesize/degrade a bacterial second messenger cyclic diguanylate (c-di-GMP) in response to blue/green light [6–8]. The cooperative action of SesA/B/C enables blue light-ON and green light-OFF regulation of the c-di-GMP-dependent cell aggregation of the thermophilic cyanobacterium Thermosynechococcus vulcanus [8, 9]. Here, we report that SesA/B/C can serve as a physiological sensor of cell density. Because cyanobacterial cells show lower transmittance of blue light than green light, higher cell density gives more green light-enriched irradiance to cells. The cell density-dependent suppression of cell aggregation under blue/green-mixed light and white light conditions support this idea. Such a sensing mechanism may provide information about the cell position in cyanobacterial mats in hot springs, the natural habitat of Thermosynechococcus. This cell position-dependent SesA/B/C-mediated regulation of cellular sessility (aggregation) might be ecophysiologically essential for the reorganization and growth of phototrophic mats. We also report that the green light-induced dispersion of cell aggregates requires red light-driven photosynthesis. Blue/green CBCRs might work as shade detectors in a different niche than red/far-red phytochromes, which may be why CBCRs have evolved in cyanobacteria.

Perancangan Sistem Kontrol Lampu Lalulintas Cerdas Dengan Menggunakan Mikrokontroler dan Kamera

Jurnal MIPA ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 200
Author(s):  
Tjerie Pangemanan ◽  
Arnold Rondonuwu
Keyword(s):  
Real Time ◽  
Digital Image ◽  
Red Light ◽  
Green Light ◽  
Processing Method ◽  
Traffic Lights ◽  
Traffic System ◽  
Road Users ◽  
Adjustment System ◽  
System Time

Masalah lalu lintas  merupakan salah satu  masalah yang sangat sulit diatasi dengan hanya menggunakan system waktu (timer). Oleh sebab itu diperlukan suatu system pengaturan otomatis yang bersifat real-time sehingga waktu pengaturan lampu lalu lintas dapat disesuaikan dnegan keadaan di lapangan. Penelitian ini bertujuan mengembangkan suatu simulasi sistem yang mampu mengestimasi panjang antrian kendaraan menggunakan metoda pengolahan citra digital hanya dengan menggunakan satu kamera untuk dijadikan parameter masukan  dalam menghitung lama waktu nyala lampu merah dan lampu hijau. Oleh karena itu, sistem lalulintas sangatlah diperlukan, sebagai sarana dan prasarana untuk menjadikan lalulintas lancar, aman, bahkan sebagai media pembelajaran disiplin bagi masyarakat pengguna jalan raya. Penelitian ini penulis menggunakan sistem pengontrolan berbasis citra digital dimana camera sebagai sensor. Untuk aplikasi dari  semua metode dalam penelitian ini digunakan Microcontroller AurdinoTraffic problems is one of the problems that is very difficult to overcome by only using the system time (timer). Therefore we need an automatic real-time adjustment system so that the time settings for traffic lights can be adjusted according to the conditions on the ground. This study aims to develop a system simulation that is able to estimate the length of the vehicle queue using a digital image processing method using only one camera to be used as input parameters in calculating the length of time the red light and green light. Therefore, the traffic system is very necessary, as a means and infrastructure to make traffic smooth, safe, even as a medium for disciplined learning for road users. In this study the authors used a digital image-based control system where the camera as a sensor. For the application of all methods in this study, Aurdino Microcontroller is used

Solution Processed Sb2S3-based Photocathode with Enhanced Photocatalytic Performance via Constructing Ultrathin TiO2 Overlayer and Noble Metal Modification

2021 ◽  
Author(s):  
Yanwen Wang ◽  
Rong Liang ◽  
Chao Qin ◽  
Lei Ren ◽  
Zhizhen Ye ◽  
...  
Keyword(s):  
Visible Light ◽  
Noble Metal ◽  
Photocatalytic Performance ◽  
Low Cost ◽  
Light Response ◽  
Solution Processed ◽  
Antimony Sulfide ◽  
Visible Light Response ◽  
Absorbing Material

Antimony sulfide (Sb2S3) is a light absorbing material with strong visible light response, which is suitable for efficient and low-cost photoelectrodes. Nano-structured films have unique advantages in constructing photoelectrodes due...

scholarly journals Quantitative Trait Loci Controlling Light and Hormone Response in Two Accessions ofArabidopsis thaliana

Genetics ◽  
2002 ◽  
Vol 160 (2) ◽  
pp. 683-696 ◽  
Author(s):  
Justin O Borevitz ◽  
Julin N Maloof ◽  
Jason Lutes ◽  
Tsegaye Dabi ◽  
Joanna L Redfern ◽  
...  
Keyword(s):  
Quantitative Trait Loci ◽  
Quantitative Trait ◽  
Natural Variation ◽  
Red Light ◽  
Light Response ◽  
Environment Interaction ◽  
Isogenic Line ◽  
Hormone Response ◽  
New Genes ◽  
Trait Loci

AbstractWe have mapped quantitative trait loci (QTL) responsible for natural variation in light and hormone response between the Cape Verde Islands (Cvi) and Landsberg erecta (Ler) accessions of Arabidopsis thaliana using recombinant inbred lines (RILs). Hypocotyl length was measured in four light environments: white, blue, red, and far-red light and in the dark. In addition, white light plus gibberellin (GA) and dark plus the brassinosteroid biosynthesis inhibitor brassinazole (BRZ) were used to detect hormone effects. Twelve QTL were identified that map to loci not previously known to affect light response, as well as loci where candidate genes have been identified from known mutations. Some QTL act in all environments while others show genotype-by-environment interaction. A global threshold was established to identify a significant epistatic interaction between two loci that have few main effects of their own. LIGHT1, a major QTL, has been confirmed in a near isogenic line (NIL) and maps to a new locus with effects in all light environments. The erecta mutation can explain the effect of the HYP2 QTL in the blue, BRZ, and dark environments, but not in far-red. LIGHT2, also confirmed in an NIL, has effects in white and red light and shows interaction with GA. The phenotype and map position of LIGHT2 suggest the photoreceptor PHYB as a candidate gene. Natural variation in light and hormone response thus defines both new genes and known genes that control light response in wild accessions.

scholarly journals Modeling Energy LED Light Consumption Based on an Artificial Intelligent Method Applied to Closed Plant Production System

2021 ◽  
Vol 11 (6) ◽  
pp. 2735
Author(s):  
Ernesto Olvera-Gonzalez ◽  
Martín Montes Rivera ◽  
Nivia Escalante-Garcia ◽  
Eduardo Flores-Gallegos
Keyword(s):  
Energy Consumption ◽  
Energy Savings ◽  
Nonlinear Models ◽  
Light Emitting Diode ◽  
Red Light ◽  
Green Light ◽  
Plant Production ◽  
Production Plant ◽  
Light Component ◽  
Gp Model

Artificial lighting is a key factor in Closed Production Plant Systems (CPPS). A significant light-emitting diode (LED) technology attribute is the emission of different wavelengths, called light recipes. Light recipes are typically configured in continuous mode, but can also be configured in pulsed mode to save energy. We propose two nonlinear models, i.e., genetic programing (GP) and feedforward artificial neural networks (FNNs) to predict energy consumption in CPPS. The generated models use the following input variables: intensity, red light component, blue light component, green light component, and white light component; and the following operation modes: continuous and pulsed light including pulsed frequency, and duty cycle as well energy consumption as output. A Spearman's correlation was applied to generate a model with only representative inputs. Two datasets were applied. The first (Test 1), with 5700 samples with similar input ranges, was used to train and evaluate, while the second (Test 2), included 160 total datapoints in different input ranges. The metrics that allowed a quantitative evaluation of the model's performance were MAPE, MSE, MAE, and SEE. Our implemented models achieved an accuracy of 96.1% for the GP model and 98.99% for the FNNs model. The models used in this proposal can be applied or programmed as part of the monitoring system for CPPS which prioritize energy efficiency. The nonlinear models provide a further analysis for energy savings due to the light recipe and operation light mode, i.e., pulsed and continuous on artificial LED lighting systems.

scholarly journals Artificial complementary chromatic acclimation gene expression system in Escherichia coli

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Dwi Ariyanti ◽  
Kazunori Ikebukuro ◽  
Koji Sode
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Light Exposure ◽  
Expression System ◽  
Red Light ◽  
Green Light ◽  
Light Illumination ◽  
Multiple Gene ◽  
Gene Expression System ◽  
Chromatic Acclimation

Abstract Background The development of multiple gene expression systems, especially those based on the physical signals, such as multiple color light irradiations, is challenging. Complementary chromatic acclimation (CCA), a photoreversible process that facilitates the control of cellular expression using light of different wavelengths in cyanobacteria, is one example. In this study, an artificial CCA systems, inspired by type III CCA light-regulated gene expression, was designed by employing a single photosensor system, the CcaS/CcaR green light gene expression system derived from Synechocystis sp. PCC6803, combined with G-box (the regulator recognized by activated CcaR), the cognate cpcG2 promoter, and the constitutively transcribed promoter, the PtrcΔLacO promoter. Results One G-box was inserted upstream of the cpcG2 promoter and a reporter gene, the rfp gene (green light-induced gene expression), and the other G-box was inserted between the PtrcΔLacO promoter and a reporter gene, the bfp gene (red light-induced gene expression). The Escherichia coli transformants with plasmid-encoded genes were evaluated at the transcriptional and translational levels under red or green light illumination. Under green light illumination, the transcription and translation of the rfp gene were observed, whereas the expression of the bfp gene was repressed. Under red light illumination, the transcription and translation of the bfp gene were observed, whereas the expression of the rfp gene was repressed. During the red and green light exposure cycles at every 6 h, BFP expression increased under red light exposure while RFP expression was repressed, and RFP expression increased under green light exposure while BFP expression was repressed. Conclusion An artificial CCA system was developed to realize a multiple gene expression system, which was regulated by two colors, red and green lights, using a single photosensor system, the CcaS/CcaR system derived from Synechocystis sp. PCC6803, in E. coli. The artificial CCA system functioned repeatedly during red and green light exposure cycles. These results demonstrate the potential application of this CCA gene expression system for the production of multiple metabolites in a variety of microorganisms, such as cyanobacteria.

scholarly journals Recent advances in radiation detection technologies enabled by metal-halide perovskites

2021 ◽  
Author(s):  
Tiebin Yang ◽  
Feng Li ◽  
Rongkun Zheng
Keyword(s):  
Gamma Rays ◽  
Performance Optimization ◽  
Radiation Detection ◽  
High Energy ◽  
Device Performance ◽  
High Energy Radiation ◽  
Energy Radiation ◽  
Halide Perovskites ◽  
Alpha Beta ◽  
Detection Technologies

Perovskite halides hold great potential for high-energy radiation detection. Recent advancements in detecting alpha-, beta-, X-, and gamma-rays by perovskite halides are reviewed and an outlook on the device performance optimization is provided.

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