scholarly journals Reducing the Impacts of Biofouling in RO Membrane Systems through In Situ Low Fluence Irradiation Employing UVC-LEDs

Membranes ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 415
Author(s):  
Philipp Sperle ◽  
Christian Wurzbacher ◽  
Jörg E. Drewes ◽  
Bertram Skibinski
Keyword(s):  
Hydraulic Resistance ◽  
Extracellular Polymeric Substances ◽  
Residual Effect ◽  
Feed Stream ◽  
Membrane Systems ◽  
Light Emitting ◽  
Cycle Arrest ◽  
Uv Led ◽  
Biofouling Control

Biofouling is a major concern for numerous reverse osmosis membrane systems. UV pretreatment of the feed stream showed promising results but is still not an established technology as it does not maintain a residual effect. By conducting accelerated biofouling experiments in this study, it was investigated whether low fluence UV in situ treatment of the feed using UVC light-emitting diodes (UVC-LEDs) has a lasting effect on the biofilm. The application of UVC-LEDs for biofouling control is a novel hybrid technology that has not been investigated, yet. It could be shown that a low fluence of 2 mJ∙cm−2 delays biofilm formation by more than 15% in lab-scale experiments. In addition, biofilms at the same feed channel pressure drop exhibited a more than 40% reduced hydraulic resistance. The delay is probably linked to the inactivation of cells in the feed stream, modified adsorption properties or an induced cell cycle arrest. The altered hydraulic resistance might be caused by a change in the microbial community, as well as reduced adenosine triphosphate levels per cells, possibly impacting quorum sensing and extracellular polymeric substances production. Due to the observed biofilm attributes, low fluence UV-LED in situ treatment of the feed stream seems to be a promising technology for biofouling control.

Fabrication and antimicrobial effects of silver nanoparticle-poly(N-isopropylacrylamide)-poly(ferrocenylsilane) hydrogel composites

2012 ◽  
Vol 1453 ◽  
Author(s):  
Xiaofeng Sui ◽  
Xueling Feng ◽  
Andrea Di Luca ◽  
Clemens A. van Blitterswijk ◽  
Lorenzo Moroni ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Light Emitting ◽  
Uv Led ◽  
Hydrogel Network ◽  
Redox Responsive ◽  
Equilibrium Swelling ◽  
Hydrogel Composites ◽  
Equilibrium Swelling Ratio ◽  
Strong Antimicrobial Activity

ABSTRACTNovel hydrogels composed of thermo-responsive poly(N-isopropylacrylamide) (PNIPAM) and redox-responsive poly(ferrocenylsilane) (PFS) macromolecules were formed by photopolymerization. PFS chains bearing acrylate side groups were copolymerized with NIPAM and N,N’-methylenebisacrylamide in tetrahydrofuran in a predetermined ratio under ultraviolet light-emitting diode (UV-LED) irradiation at a wavelength of 365 nm, in the presence of a photoinitiator. Crosslinking occurred smoothly, providing homogeneous hydrogels. The equilibrium swelling ratio, rheology and morphology of these hybrid PNIPAM-PFS-based hydrogels were investigated. In-situ fabrication of silver nanoparticles inside the hydrogel network via reduction of silver nitrate by the PFS chains led to hydrogel composites. These composites showed strong antimicrobial activity while maintaining a high biocompatibility with cells.

scholarly journals Design of a Secondary Freeform Lens of UV LED Mosquito-Trapping Lamp for Enhancing Trapping Efficiency

Crystals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 335 ◽  
Author(s):  
Wei-Hsiung Tseng ◽  
Diana Juan ◽  
Wei-Cheng Hsiao ◽  
Cheng-Han Chan ◽  
Hsin-Yi Ma ◽  
...  
Keyword(s):  
Light Intensity ◽  
Intensity Distribution ◽  
Light Emitting Diode ◽  
Trapping Efficiency ◽  
Axially Symmetric ◽  
Light Intensity Distribution ◽  
Light Emitting ◽  
Led Light ◽  
Uv Led ◽  
Freeform Lens

In this study, our proposed ultraviolet light-emitting diode (UV LED) mosquito-trapping lamp is designed to control diseases brought by insects such as mosquitoes. In order to enable the device to efficiently catch mosquitoes in a wider area, a secondary freeform lens (SFL) is designed for UV LED. The lens is mounted on a 3 W UV LED light bar as a mosquito-trapping lamp of the new UV LED light bar module to achieve axially symmetric light intensity distribution. The special SFL is used to enhance the trapping capabilities of the mosquito-trapping lamp. The results show that when the secondary freeform surface lens is applied to the experimental outdoor UV LED mosquito-trapping lamp, the trapping range can be expanded to 100π·m2 and the captured mosquitoes increased by about 300%.

scholarly journals Dimension control of in situ fabricated CsPbClBr2 nanocrystal films toward efficient blue light-emitting diodes

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Chenhui Wang ◽  
Dengbao Han ◽  
Junhui Wang ◽  
Yingguo Yang ◽  
Xinyue Liu ◽  
...  
Keyword(s):  
Quantum Well ◽  
Light Emitting Diodes ◽  
Blue Emission ◽  
Light Emitting ◽  
Mixed Ligands ◽  
Dimension Control ◽  
Nanocrystal Films ◽  
Width Distribution ◽  
Quantum Well Width

AbstractIn the field of perovskite light-emitting diodes (PeLEDs), the performance of blue emissive electroluminescence devices lags behind the other counterparts due to the lack of fabrication methodology. Herein, we demonstrate the in situ fabrication of CsPbClBr2 nanocrystal films by using mixed ligands of 2-phenylethanamine bromide (PEABr) and 3,3-diphenylpropylamine bromide (DPPABr). PEABr dominates the formation of quasi-two-dimensional perovskites with small-n domains, while DPPABr induces the formation of large-n domains. Strong blue emission at 470 nm with a photoluminescence quantum yield up to 60% was obtained by mixing the two ligands due to the formation of a narrower quantum-well width distribution. Based on such films, efficient blue PeLEDs with a maximum external quantum efficiency of 8.8% were achieved at 473 nm. Furthermore, we illustrate that the use of dual-ligand with respective tendency of forming small-n and large-n domains is a versatile strategy to achieve narrow quantum-well width distribution for photoluminescence enhancement.

scholarly journals Evaluation of a Multicommuted Flow System for Photometric Environmental Measurements

2006 ◽  
Vol 2006 ◽  
pp. 1-9 ◽  
Author(s):  
Eva Ródenas-Torralba ◽  
Fábio R. P. Rocha ◽  
Boaventura F. Reis ◽  
Ángel Morales-Rubio ◽  
Miguel de la Guardia
Keyword(s):  
Sodium Nitroprusside ◽  
Confidence Level ◽  
System Performance ◽  
Flow System ◽  
Flow Analysis ◽  
Light Emitting ◽  
Analysis Instrument ◽  
Hardware Configuration ◽  
Photometric Measurements

A portable flow analysis instrument is described for in situ photometric measurements. This system is based on light-emitting diodes (LEDs) and a photodiode detector, coupled to a multipumping flow system. The whole equipment presents dimensions of25 cm×22 cm×10 cm, weighs circa 3 kg, and costs 650 €. System performance was evaluated for different chemistries without changing hardware configuration for determinations of (i)Fe3+withSCN-, (ii) iodometric nitrite determination, (iii) phenol with sodium nitroprusside, and (iv) 1-naphthol-N-methylcarbamate (carbaryl) withp-aminophenol. The detection limits were estimated as 22, 60, 25, and 60 ngmL-1for iron, nitrite, phenol, and carbaryl at the 99.7% confidence level with RSD of 2.3, 1.0, 1.8, and 0.8%, respectively. Reagent and waste volumes were lower than those obtained by flow systems with continuous reagent addition. Sampling rates of 100, 110, 65, and 72 determinations per hour were achieved for iron, nitrite, phenol, and carbaryl determinations

Excitonic Creation of Highly Luminescent Defects In Situ in Working Organic Light-Emitting Diodes

2017 ◽  
Vol 6 (2) ◽  
pp. 1700856 ◽  
Author(s):  
Yong-Biao Zhao ◽  
Grayson L. Ingram ◽  
Xi-Wen Gong ◽  
Xi-Yan Li ◽  
Li-Na Quan ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Organic Light

scholarly journals Suppressing the Initial Growth of Sidewall GaN by Modifying Micron-Sized Patterned Sapphire Substrate with H3PO4-Based Etchant

Micromachines ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 622 ◽  
Author(s):  
Wen-Yang Hsu ◽  
Yuan-Chi Lian ◽  
Pei-Yu Wu ◽  
Wei-Min Yong ◽  
Jinn-Kong Sheu ◽  
...  
Keyword(s):  
Sapphire Substrate ◽  
Light Emitting Diodes ◽  
Ex Situ ◽  
Initial Growth ◽  
Patterned Sapphire Substrate ◽  
Light Emitting ◽  
Sapphire Substrates ◽  
Patterned Sapphire Substrates

Micron-sized patterned sapphire substrates (PSS) are used to improve the performance of GaN-based light-emitting diodes (LEDs). However, the growth of GaN is initiated not only from the bottom c-plane but also from the sidewall of the micron-sized patterns. Therefore, the coalescence of these GaN crystals creates irregular voids. In this study, two kinds of nucleation layers (NL)—ex-situ AlN NL and in-situ GaN NL—were used, and the growth of sidewall GaN was successfully suppressed in both systems by modifying the micron-sized PSS surface.

Comparison of supplemental cobalt form on fibre digestion and cobalamin concentrations in cattle

2017 ◽  
Vol 155 (5) ◽  
pp. 832-838 ◽  
Author(s):  
R. C. WATERMAN ◽  
W. L. KELLY ◽  
C. K. LARSON ◽  
M. K. PETERSEN
Keyword(s):  
Crude Protein ◽  
Dry Matter ◽  
National Research Council ◽  
Residual Effect ◽  
Vitamin B ◽  
Serum Concentrations ◽  
Forage Digestibility ◽  
Randomized Experimental Design ◽  
To Receive

SUMMARYCobalt (Co) is essential for rumen microbial metabolism to synthesize methane, acetate and methionine. It also serves as a structural component of vitamin B12(cobalamin), which functions as a coenzyme in energy metabolism. A study was conducted to determine if Co form (carbonatev. glucoheptonate) supplemented above the National Research Council requirements would improve digestibility of a low-quality forage diet and change serum cobalamin concentrations. Nineteen ruminally cannulated cows (577 ± 13 kg) were fed individually in a completely randomized experimental design. Cows were fed a grass hay diet that contained (79·2 g/kg crude protein, 565 g/kg total digestible nutrients, 633·2 g/kg neutral detergent fibre (NDF), 874·2 g/kg dry matter) at a rate of 0·02% of body weight on a as fed basis for a 62-day study, which consisted of three periods; acclimation (AC), treatment (TR) and residual (RE). Measurements taken in the AC period were used as covariates for analysis in the TR and RE periods. Cows were stratified by age (5 ± 0·4 years) and lactational history, and assigned to receive 12·5 mg supplemental Co in one of two forms: (1) 27·2 mg of Co carbonate (CC,n= 11 cows) or (2) 50 mg of Co glucoheptonate (CGH,n= 8 cows). Supplement was administered daily via a gelatin capsule placed directly into the rumen 2 h after feeding. During the last 96 h of each period, forage digestibility was measured using anin situnylon bag technique. Blood samples were collected 4 and 6 h following feeding, and 24 h before the end of each period. A treatment × period interaction was detected forin situorganic matter (OM) disappearance at 96 h; (TR period: 684 and 708 ± 81 g/kg; RE period: 676 and 668 ± 75 g/kg, for CC and CGH, respectively). Once inclusion of Co in the CGH group was removed, OM disappearance was reduced by 4·01% compared with 0·82% in the CC cows. The NDF disappearance (OM basis) was less for the TR compared with the RE at 48 h (629 and 652 ± 39 g/kg, respectively). However, by 96 h NDF disappearance was greater for TR than the RE (704 and 689 ± 44 g/kg; respectively). No differences were detected for cobalamin serum concentrations or rate of fibre fermentation. The outcomes of the current research signify that there may be a slight residual effect of Co supplementation on fermentation; there was also an indication that Co source may enhance the overall extent of fermentation.

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