Dual-Wavelength (UV and Blue) Controlled Photopolymerization Confinement for 3D-Printing: Modeling and Analysis of Measurements

The kinetics and modeling of dual-wavelength (UV and blue) controlled photopolymerization confinement (PC) are presented and measured data are analyzed by analytic formulas and numerical data. The UV-light initiated inhibition effect is strongly monomer-dependent due to different C=C bond rate constants and conversion efficacies. Without the UV-light, for a given blue-light intensity, higher initiator concentration (C10) and rate constant (k’) lead to higher conversion, as also predicted by analytic formulas, in which the total conversion rate (RT) is an increasing function of C1 and k’R, which is proportional to k’[gB1C1]0.5. However, the coupling factor B1 plays a different role that higher B1 leads to higher conversion only in the transient regime; whereas higher B1 leads to lower steady-state conversion. For a fixed initiator concentration C10, higher inhibitor concentration (C20) leads to lower conversion due to a stronger inhibition effect. However, same conversion reduction was found for the same H-factor defined by H0 = [b1C10 − b2C20]. Conversion of blue-only are much higher than that of UV-only and UV-blue combined, in which high C20 results a strong reduction of blue-only-conversion, such that the UV-light serves as the turn-off (trigger) mechanism for the purpose of spatial confirmation within the overlap area of UV and blue light. For example, UV-light controlled methacrylate conversion of a glycidyl dimethacrylate resin is formulated with a tertiary amine co-initiator, and butyl nitrite. The system is subject to a continuous exposure of a blue light, but an on-off exposure of a UV-light. Finally, we developed a theoretical new finding for the criterion of a good material/candidate governed by a double ratio of light-intensity and concentration, [I20C20]/[I10C10].

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Dual-Wavelength (UV and Blue) Controlled Photopolymerization Confinement for 3D-Printing: Modeling and Analysis of Measurements

10.20944/preprints201910.0196.v1 ◽

2019 ◽

Author(s):

Jui-Teng Lin ◽

Da-Chuan Cheng ◽

Kuo-Ti Chen ◽

Hsia-Wei Liu

Keyword(s):

Light Intensity ◽

Blue Light ◽

Uv Light ◽

Numerical Data ◽

Coupling Factor ◽

Dual Wavelength ◽

Continuous Exposure ◽

Initiator Concentration ◽

Modeling And Analysis ◽

Inhibition Effect

The kinetics and modeling of dual-wavelength controlled photopolymerization confinement (PC) are presented and measured data are analyzed by analytic formulas and numerical data. The UV-light initiated inhibition effect is strongly monomer-dependent and different monomers have different C=C bond rate constants and conversion efficacy. Without the UV-light, for a given blue-light intensity, higher initiator concentration (C10) and rate constant (k’) lead to higher conversion, as also predicted by analytic formulas, in which the total conversion rate (RT) is an increasing function of k’R, which is proportional to k[gB1C1]0.5. However, the coupling factor b1 plays a different role that higher b1 leads to higher conversion only in the transient regime; whereas higher b1 leads lower steady-state conversion. For a fixed initiator concentration C10, higher inhibitor concentration (C20) leads to lower conversion due to stronger inhibition effect. However, same conversion reduction was found for the same H-factor of H0 = [b1C10 - b2C20]. Conversion of blue-only are much higher than that of UV-only and UV-blue combined, in which high C20 results a strong reduction of blue-only-conversion, such that the UV-light serves as the turn-off (trigger) mechanism for the purpose of spatial confirmation within the overlap area of UV and blue light. For example, UV-light controlled methacrylate conversion of a glycidyl dimethacrylate resin formulated with a tertiary amine co-initiator, and butyl nitrite, subject to a continuous exposure of a blue light, but an on-off exposure of a UV-light. Finally, we developed a theoretical new finding for the criterion of a good material/candidate governed by a double ratio of light-intensity and concentration, [I20C20.]/[I10C10].

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Preparation, Characterization, and Sludge Conditioning of Cationic Polyacrylamide Synthesized by a Novel UV-Initiated System

10.20944/preprints201808.0005.v1 ◽

2018 ◽

Author(s):

Qingqing Guan ◽

Guocheng Zhu ◽

Yi Liao ◽

Jin Xu ◽

Xiaoxu Sun ◽

...

Keyword(s):

Light Intensity ◽

Intrinsic Viscosity ◽

Uv Light ◽

Proton Nuclear Magnetic Resonance ◽

Initiator Concentration ◽

Floc Size ◽

Cationic Polyacrylamide ◽

Sedimentation Behavior ◽

Redox Initiator ◽

Sludge Conditioning

Controlling the concentration of free radicals in polymerization systems is advantageous for preparing cationic polyacrylamide (CPAM) with high molecular weight and acceptable dissolvability. In this study, a novel ultraviolet (UV)-initiated system characterized with adjustable light intensity and redox-azo complex initiator was used to synthesize a CPAM flocculant named NP. Comparatively, another CPAM flocculant named SP with stable UV light intensity and single initiator was prepared. The chemical structure, morphology, and thermal stability were analyzed through instrumental analysis. Proton nuclear magnetic resonance indicated that NP was successfully prepared, and a small fraction of cationic homopolymer was mixed in the product. Polymerization conditions were optimized, and polymerization mechanism was determined by investigating the effects of various parameters on intrinsic viscosity, conversion, and dissolvability. Results showed that the best performance was obtained at indexes of 0.45 wt&permil; redox initiator concentration, 0.2 wt&permil; azo initiator concentration, 40.0 wt% of cationic monomer, first- and second-stage light intensities of 8.5 and 13 mW/cm2, respectively, and 3 wt% urea. Sludge conditioning performances of NP and SP were comparatively evaluated, and the mechanism was determined by investigating the sedimentation behavior and floc size distribution. High intrinsic viscosity, porous morphology structure, and the mixed cationic homopolymer of NP resulted in better sludge conditioning performance.

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Effect of Pre-Harvest Supplemental UV-A/Blue and Red/Blue LED Lighting on Lettuce Growth and Nutritional Quality

Horticulturae ◽

10.3390/horticulturae7040080 ◽

2021 ◽

Vol 7 (4) ◽

pp. 80

Author(s):

Triston Hooks ◽

Joseph Masabni ◽

Ling Sun ◽

Genhua Niu

Keyword(s):

Blue Light ◽

Nutritional Quality ◽

Uv Light ◽

Ultra Violet ◽

Photon Flux ◽

Photon Flux Density ◽

Daily Light Integral ◽

Lettuce Growth ◽

Supplemental Lighting

Blue light and ultra-violet (UV) light have been shown to influence plant growth, morphology, and quality. In this study, we investigated the effects of pre-harvest supplemental lighting using UV-A and blue (UV-A/Blue) light and red and blue (RB) light on growth and nutritional quality of lettuce grown hydroponically in two greenhouse experiments. The RB spectrum was applied pre-harvest for two days or nights, while the UV-A/Blue spectrum was applied pre-harvest for two or four days or nights. All pre-harvest supplemental lighting treatments had a same duration of 12 h with a photon flux density (PFD) of 171 μmol m−2 s−1. Results of both experiments showed that pre-harvest supplemental lighting using UV A/Blue or RB light can increase the growth and nutritional quality of lettuce grown hydroponically. The enhancement of lettuce growth and nutritional quality by the pre-harvest supplemental lighting was more effective under low daily light integral (DLI) compared to a high DLI and tended to be more effective when applied during the night, regardless of spectrum.

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Photodegradation of Trace Trichloronitromethane in Water under UV Irradiation

Journal of Chemistry ◽

10.1155/2014/283496 ◽

2014 ◽

Vol 2014 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Lin Deng ◽

Zhiren Wu ◽

Caiqian Yang ◽

Yung-Li Wang

Keyword(s):

Humic Acid ◽

Light Intensity ◽

Uv Light ◽

Control Strategies ◽

Chloride Ions ◽

Source Control ◽

Photochemical Degradation ◽

Nitrate Ions ◽

Photodegradation Rate ◽

Water And Wastewater

This study’s objective was to study the photodegradation of TCNM (trichloronitromethane) in water under UV light. The effects of light intensity, nitrate ions, chloride ions, humic acid, and pH on the photochemical degradation of TCNM were investigated under the irradiation of low pressure mercury lamp (λ= 254 nm, 12 W). The photodegradation rate of TCNM was found to increase with increasing the concentration of nitrate ions, chloride ions, humic acid, pH, and light intensity. The photodegradation of TCNM was examined at pH 6.0 with initial concentrations (C0) of TCNM at 10.0–200.0 µg/L. The overall rate of degradation of TCNM was modeled using a pseudofirst-order rate law. Finally, the proposed mechanism involved in the photodegradation of TCNM was also discussed by analysis. Results of this study can contribute to the development of new source control strategies for minimization of TCNM risk at drinking water and wastewater utilities.

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The Effects of Day Length and Light Intensity on Tile Growth of Barley

Australian Journal of Biological Sciences ◽

10.1071/bi9690053 ◽

1969 ◽

Vol 22 (1) ◽

pp. 53 ◽

Cited By ~ 2

Author(s):

D Aspinall

Keyword(s):

Light Intensity ◽

Linear Relationship ◽

Light Source ◽

Blue Light ◽

Floral Development ◽

Red Light ◽

Day Length

The acceleration of flowering in barley due to the inclusion of incandescent illumination in the light source has been shown to be due to the far�red content of the light. A linear relationship between floral development and intensity of far�red light in a 16�hr photoperiod has been established with the cultivar CI5611. Barley appears to be relatively unresponsive to blue light, however.

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Treatment of High-Strength Animal Industrial Wastewater Using Photo-Assisted Fenton Oxidation Coupled to Photocatalytic Technology

Water ◽

10.3390/w11081553 ◽

2019 ◽

Vol 11 (8) ◽

pp. 1553 ◽

Cited By ~ 1

Author(s):

Jae Hong Park ◽

Dong Seok Shin ◽

Jae Kwan Lee

Keyword(s):

Light Intensity ◽

Removal Efficiency ◽

Industrial Wastewater ◽

Uv Light ◽

High Strength ◽

Cod Removal ◽

Fenton Oxidation ◽

Optimal Conditions ◽

Experimental Conditions ◽

Animal Wastewater

Animal wastewater is one of the wastewaters that has a color and is difficult to treat because it contains a large amount of non-degradable organic materials. The photo-assisted Fenton oxidation technique was applied to treat animal wastewater, and the optimal conditions of chemical oxygen demands (COD) removal were analyzed according to changes in pH, ferrous ion, H2O2, and ultraviolet (UV) light intensity as a single experimental condition. Experimental results showed that, under the single-factor experimental conditions, the optimal conditions for degradation of animal wastewater were pH 3.5, Fe(II) 0.01 M, H2O2 0.1 M, light intensity 3.524 mW/m2. Under the optimal conditions, COD removal efficiency was 91%, sludge production was 2.5 mL from 100 mL of solution, color removal efficiency was 80%, and coliform removal efficiency was 99.5%.

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Kinetic Study of Photoinitiated Frontal Polymerization. Influence of UV Light Intensity Variations on the Conversion Profiles

Macromolecules ◽

10.1021/ma901535p ◽

2010 ◽

Vol 43 (1) ◽

pp. 177-184 ◽

Cited By ~ 19

Author(s):

N. Hayki ◽

L. Lecamp ◽

N. Désilles ◽

P. Lebaudy

Keyword(s):

Light Intensity ◽

Kinetic Study ◽

Uv Light ◽

Frontal Polymerization

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Nocturnal hatching in the monogenean skin parasiteEntobdella hippoglossifrom the halibut,Hippoglossus hippoglossus

Parasitology ◽

10.1017/s0031182000045704 ◽

1974 ◽

Vol 68 (2) ◽

pp. 161-172 ◽

Cited By ~ 23

Author(s):

Graham C. Kearn

Keyword(s):

Light Intensity ◽

Blue Light ◽

Epidermal Cells ◽

Free Swimming ◽

Skin Mucus ◽

Hippoglossus Hippoglossus ◽

Monogenean Parasite ◽

The Relationship

When eggs of the monogenean parasiteEntobdella hippoglossi, from the skin of the halibut (Hippoglossus hippoglossus), are incubated at 7 °C in alternating 12 h periods of dim blue light (intensity about 3 nW/cm2) and darkness, free-swimming larvae are recovered mostly at the end of the first 2 h of the period of darkness. Larvae do not emerge in significant numbers when the eggs are mechanically disturbed during the light or dark periods, or when the eggs are placed in shadow for periods of 5–25 min during the illumination period. The treatment of fully developed eggs with washings from halibut or from sole or with halibut skin mucus failed to produce hatching.The free-swimming life of the larvae at 7 °C is in excess of 24 h and within 4 h of hatching at 4 °C some larvae are able to attach themselves to halibut skin and shed their ciliated epidermal cells.The relationship between the hatching pattern of the eggs of the parasite and the behaviour of the halibut is discussed.

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