Effects Of Different Wavelengths Research Articles

OpenFOAM analysis of the wave radiation by a box-type floating structure

Wave radiation due to heave, surge, and pitch by a box-type floating structure based on computational fluid dynamics (CFD) simulations using OpenFOAM is analysed. The CFD simulation results include surge and heave forces and response amplitude operator for the heave, surge, and pitch at different wave lengths. The numerical simulation results of heave force due to incoming waves and resulting motion are compared against experimental data and linearized analytical solutions based on velocity potential flow theory. The hydrodynamic effect on the width and draft of the structure in analytical results for vertical wave force, horizontal wave force, and torque are studied whilst, the effect of different wave lengths on heave, surge and pitch forces and response amplitude operator from CFD results are analysed. The comparison shows that the CFD results are in good agreement with the experimental ones and are very close to the analytical ones. The paper concludes that CFD is well capable of simulating wave interaction behaviour of a box-type floating structure for wave energy converters, and the developed analytical model can serve as an efficient middle-fidelity performance evaluation tool for such structures during design development stage.

P‐4.5: The Applications of Micro‐LED Arrays in The Medical Field

With the continuous improvement of the quality of life of modern people, people's requirements for lighting continue to increase. In addition to working and living lighting, lighting plays a vital role in medical care. As a medical device, Micro‐LED array has the advantages of small size, light weight, good monochromaticity, fast response, large light intensity and long lifetime. In this paper, the effects of different wavelengths of light on the human body are described respectively, and the application of Micro‐LED arrays in acne treatment and blood oxygenation is proposed.

Outage probability and average BER estimation of FSO system employing wavelength diversity

Free space optical (FSO) communication has gained significant attention among researchers for high bandwidth and secured data transfer applications. However, its performance is limited by the local atmospheric conditions. This paper focusses on an FSO system employing a diversity method to compensate signal loss occurred due to atmospheric turbulence conditions varying from moderate to strong. We derive a closed-form expression for two important parameters, viz.: average bit error rate (BER) and outage probability over gamma–gamma distribution channel. The numerical results for different combining schemes are presented in this paper. Enhancement in reliability and performance of FSO communication system with wavelength diversity is investigated. Effect of different wavelengths 850 nm, 1310 nm and 1550 nm on average BER is analysed and minimum BER is achieved for optimal combining at 1550 nm at diversity order $$R=3$$ .

Laser surface texturing of β-Ti alloy for orthopaedics: Effect of different wavelengths and pulse durations

Abstract In this work laser surface texturing of Ti-11.5Mo-6Zr-4.5Sn β-Ti alloy is investigated with different laser wavelengths and pulse durations. For benchmark purposes, three different industrial solid-state laser sources providing four different wavelength/pulse duration combinations were used. Within the experimented range pulse duration could be varied at 2.5 ps, 6 ns and 250 ns at 1064 nm, while 5 ns pulse duration was tested at 355 nm. The comparative analyses were carried within the process parameter ranges available to the laser sources in order to assess the quality and productivity aspects. In particular, surface roughness, wettability, and chemical composition were quantified as well as assessing the distinct surface morphologies obtained with different configurations. Process productivity was analysed for each configuration in terms of machining rate. The results exhibit a large variety of possible surface textures available to biomedical implant designers with nanometric to micrometric features and tailorable chemical and wetting properties. Moreover, the results help in understanding how the light/matter interaction changes between different pulse durations and wavelengths.

DNA-Damaging Effect of Different Wavelength (206 and 257 nm) Femtosecond Laser Pulses.

Objective: The purpose of this study was to investigate the possible cytotoxic and genotoxic impact of new-generation 206 nm femtosecond solid-state laser irradiation on murine skin cells in vitro, and to compare the cell and DNA damage caused by different wavelength (206 vs. 257 nm) femtosecond laser pulses. Background data: The first attempts to evaluate the possible genotoxic impact of ultrashort laser pulses on the murine bone marrow cells in vitro revealed the unlooked-for DNA-damaging effect. However, the impact of far-ultraviolet (UV) radiation on genetic material of internal and external organs' cells may differ due to differences in size, structure, and biochemical composition of the cells. Methods: Mouse skin cells were exposed to different doses of 206 and 257 nm wavelength femtosecond laser, and 254 nm UV lamp irradiation. Comet assay in two versions-the standard alkaline and the enzyme-linked-was used for the evaluation of DNA damage. Results: The irradiation determined by different parameters demonstrated intensity-dependent genotoxic impact. The pyrimidine dimers made up the greater part of DNA photodamage, but with rising exposure dose the increase of relative amount of more energy-consuming primary damage-DNA strand breaks-was detected. Conclusions: The 206 nm femtosecond laser irradiation was much more cytotoxic but caused less primary DNA damage than the same pulse duration longer wavelength (257 nm) laser irradiation. DNA-damaging effect of 206 nm femtosecond laser pulses with extremely low penetration force may highly depend on the size, structure, and biochemical composition of the cells of organ or tissue targets.

Visible-light-driven reduction of nitrostyrene utilizing plasmonic silver nanoparticle catalysts immobilized on oxide supports

Abstract The localized surface plasmon resonance (LSPR) mediated enhanced chemical activity can be entitled as a promising strategy for efficient solar to chemical energy conversion. To tune the selectivity of a desired product in a chemical reaction is of paramount importance yet a great challenge. In this paper, a new strategy to effectively enhance the selectivity of the product formation under visible light irradiation is reported. A series of Ag catalysts deposited on metal oxide support materials (TiO2, ZrO2, Al2O3 and CeO2) along with their preparative techniques, optimum metal content ratio and effect of different wavelength of light is explored for the chemoselective reduction of p-nitrostyrene to p-aminostyrene under visible light irradiation. The prepared catalysts were characterized by a range of physicochemical techniques including UV–vis, transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The reduction reaction was carried out in ethanolic suspension at room temperature and pressure utilizing ammonia borane (AB) as an in-situ source of H2. The reaction results displayed 100% conversion with a maximum chemoselectivity of 81% shown by Ag/TiO2 under light irradiation conditions. The high chemoselectivity could be attributed to the preferential alignment of polar nitro group on the surface of plasmonic silver under light irradiation conditions.

Aging effects of ultraviolet lights with same dominant wavelength and different wavelength ranges on a hydrocarbon-based polymer (asphalt)

To investigate the effects of different wavelength ranges of UV lights on chemical compositions and macro-properties of asphalt, three UV lights were used to conduct the aging test of asphalt for 1–288 h. The elemental analysis and Fourier transform infrared spectroscopy (FTIR) were performed to analyze the chemical changes of asphalt, the surface micro-topographies of asphalt before and after UV aging were studied by atomic force microscopy (AFM). In addition, the physical performance, viscosity and rheological performance of asphalt was studied with softening point test and dynamic shear rheometer (DSR), respectively. The chemical compositions and structures analyses show that the oxidation mechanism exists during the UV aging of asphalt binder. The numbers of bee-like structures in AFM height figures decrease obviously after UV aging, meanwhile the sizes of which increase. The relationships of RCC, RCS and SPI values with UV expose time follow a power function model in the first 24 h, while follows a liner model after 24 h. UV lights with different wavelength ranges have significantly different effects on the chemical compositions and macro-properties of asphalt. The UV 350–370 nm has the most obvious aging effect on asphalt binder, second is the UV 340–380 nm, the UV 200–400 nm has the lightest aging effect.

The effect of different wavelengths of light during incubation on the development of rhythmic pineal melatonin biosynthesis in chick embryos

Rhythmic pineal melatonin biosynthesis develops in chick embryos incubated under a light (L)-dark (D) cycle of polychromatic white light. The spectral sensitivity of the embryonic pineal gland is not known and was investigated in this study. Broiler breeder eggs (Ross 308, n=450) were incubated under white, red, green or blue light under the 12L : 12D cycle. Melatonin was measured in extracts of pineal glands by radioimmunoassay. The daily rhythm of pineal melatonin levels in 20-day-old chick embryos was confirmed during the final stages of embryonic life under all four wavelengths of light with expected higher concentrations during dark- than light-times. The highest pineal melatonin levels were determined in chick embryos incubated under red and white light and lower levels under green light. The incubation under blue light resulted in the lowest melatonin biosynthesis. Pineal melatonin concentrations increased substantially on post-hatching day two compared with pre-hatching levels and we did not find differences between birds incubated and kept in either white or green light. Our results demonstrate a selective sensitivity of the chick embryo pineal gland to different wavelengths of light. Rhythmic melatonin production is suggested as a possible mechanism, which transfers information about the quality of ambient light to the developing avian embryo.

Photochemical response of parsley (Petroselinum crispum (Mill.) Fuss) grown under red light: The effect on the essential oil composition and yield

The effect of different wavelengths on plants morphological characters has been widely described, but also the chemical composition of the essential oil is influenced by the lighting conditions in which they are grown. In the present study, the effect of both the enrichment (reverse Emerson effect) and the monochromatic lighting treatments with red light has been evaluated on the essential oil compositions of parsley (Petroselinum crispum (Mill.) Fuss). Multivariate statistical analysis was performed on the results, with both the hierarchical cluster and principal component analyses. Whilst the red-enrichment of the light spectrum did not induce major changes in the essential oil composition, the end of the day monochromatic red (660 nm) treatment caused a chemotype switch in the essential oil and relevant differences in the overall composition, with an increment of the relative abundance of oxygenated compounds, coupled with a relevant decrement in the abundance of phenylpropanoids. The extraction yields remained unchanged in all the three tested conditions of light (control, red-enriched and monochromatic red). Different lighting conditions could be used as a tool to modulate the compounds present in the essential oil, but further studies would be advisable to assess the effects on different species and chemical classes of compounds.

Zn1−xSixO: Reduced photosensitivity, improved stability and enhanced conductivity

Effect of different wavelengths (350, 380, 390, 400, 450, 550 & 650nm) of light on surface conductivity of sol-gel synthesized Zn1−xSixO material has been observed. Enhancement in conductivity at all wavelengths of light had been attributed to enhanced charge carrier concentration with silicon doping. Reduction in sensitivity for UV and visible light wavelength indicates reduction of surface defects and deep level traps with Si4+ incorporation. Enhanced photo stability with Si4+ doping makes it an appropriate material for transparent electrodes used in various display and electronic devices.

Effect of different wavelengths of light on the antioxidant and immunity status of juvenile rock bream, Oplegnathus fasciatus, exposed to thermal stress

We investigated the effect of light wavelengths on antioxidant and immunity parameters in juvenile rock bream, Oplegnathus fasciatus, exposed to thermal stress (25 and 30°C). We exposed the fish to light emitting diodes (LEDs) emitting green (520 nm) and red light (630 nm) of 0.25 and 0.5 W/m2 intensity, and measured the activity, and mRNA and protein expression levels of the antioxidant enzymes, superoxide dismutase, catalase, and glutathione peroxidase. We also determined the levels of plasma hydrogen peroxide (H2O2), melatonin, and lysozyme. Furthermore, the mRNA and protein levels of caspase-3 were measured and terminal transferase dUTP nick end labeling (TUNEL) assays were performed. We observed that mRNA expression and activities of antioxidant enzymes and plasma H2O2 levels were significantly higher after exposure to high temperatures. However, increases in these parameters were significantly lower after exposure to green LED light. The plasma melatonin and lysozyme levels were significantly lower in the different groups after exposure to high temperatures; however, in groups exposed to green LED light, their levels were significantly higher than those in the control group. The expression pattern of caspase-3 mRNA was similar to that of H2O2. The TUNEL assay showed that apoptosis was markedly higher at higher water temperatures than that at 20°C. These results indicate that high water temperatures induce oxidative stress and decrease the immunity in juvenile rock bream but green LED light inhibits the rise in oxidative stress and combats the decrease in immunity and should, thus, be useful in the culture of rock bream.

Effect of different wavelengths and dyes on Candida albicans: In vivo study using Galleria mellonella as an experimental model

BackgroundStudies on photodynamic inactivation against microorganisms had a great development in recent years. The aim of this work was to test the application of different laser wavelengths with or without different photosensitizing dyes on Candida albicans cells in vitro and in photodynamic therapy protocols in vivo in larvae of Galleria mellonella. MethodsLaser application was realized on C. albicans cells suspended in saline solution or cultured on solid medium for the in vitro study, and in a model of G. mellonella candidal infection for the in vivo study. Three wavelengths (650, 405, and 532nm) were used in continuous mode with different values of applied fluences: 10, 20 and 30J/cm2 for the in vitro study and 10J/cm2 for the in vivo study, without and with photosensitizing dyes. ResultsNo growth inhibition was obtained on yeast cells in saline solution without photosensitizers. The maximum inhibition of growth (100%) was obtained with 405nm diode laser and curcumin at any used fluence. No growth inhibition was observed for yeast cells cultured on solid medium after laser application without dyes. An inhibition was observed after laser application when curcumin and erythrosine were added to the medium.The survival curves of G. mellonella larvae infected with C. albicans with or without the different dyes and after laser application showed a statistically significant difference (p<0.001) in comparison with the proper control groups. ConclusionsThese results show the efficacy of photodynamic inactivation exploiting a suitable combination of light and dyes against C. albicans and the potential of photodynamic therapy for the treatment of candidal infections.

Various Wavelengths of Light-Emitting Diode Light Regulate the Proliferation of Human Dermal Papilla Cells and Hair Follicles via Wnt/β-Catenin and the Extracellular Signal-Regulated Kinase Pathways.

BackgroundThe human dermal papilla cells (hDPCs) play an important role in regulation of hair cycling and growth.ObjectiveThe aim of this study was to investigate the effect of different wavelengths of light-emitting diode (LED) irradiation on the proliferation of cultured hDPCs and on the growth of human hair follicles (HFs) in vitro.MethodsWe examined the effect of LED irradiation on Wnt/β-catenin signaling and mitogen-activated protein kinase (MAPK) pathways in hDPCs. Anagen HFs were cultured with LED irradiation and elongation of each hair shaft was measured.ResultsThe most potent wavelength in promoting the hDPC proliferation is 660 nm and 830 nm promoted hDPC proliferation to a lesser extent than 660 nm. Various wavelengths significantly increased β-catenin, Axin2, Wnt3a, Wnt5a and Wnt10b mRNA expression. LED irradiation significantly increased β-catenin and cyclin D expression, and the phosphorylation of MAPK and extracellular signal-regulated kinase (ERK). HFs irradiated with 415 nm and 660 nm grew longer than control.ConclusionOur result suggests that LED has a potential to stimulate hDPC proliferation via the activation of Wnt/β-catenin signaling and ERK pathway. To our best knowledge, this is the first report which investigated that the effect of various wavelengths of LED on hDPC proliferation and the underlying mechanisms.

Effect of different colours of light on growth performance of broilers

A study was carried out to quantify the effect of different wavelengths of light on the production performance of broilers. A total of 240, day-old straight run broiler chicks were divided into 4 treatments each comprising of four replicates of 15 birds each. Chicks pertaining to treatment group G1, G2, G3 and G4 were provided blue light, green light, red light and plain incandescent light respectively. All treatments were provided continuous artificial photoperiod of 24 hours up to the rearing period (6wks). Light proofing of pens was done by black curtains. At 6weeks of age the body weight of the G1 group was found significantly higher than other groups. Again significantly higher overall body weight gain was noticed in G1 group followed by G4, G3 and G2. Feed consumption was significantly higher in G1 followed by G3, G4 and G2. Feed conversion ratio was significantly higher in G3 and lower in G1 group. It is concluded that birds reared under the blue light showed highest body weight, body weight gain and feed consumption with comparatively lower FCR.

The Effect of Different Wavelength of Light for Microbial Fuel Cell with an Anode of Rhodopseudomonas faecalis (PSB-B)

A microbial fuel cell (MFC) with an algae-assisted cathode is a low-cost and sustainable way to provide the oxygen for the oxygen reduction reaction. The anode was with anaerobic microorganism, a kind of photosynthetic bacteria (PSB-B). An algae bioreactor was connected to cathode microbial fuel cells to increase power generation by supplying more oxygen to cathode electrode. In this study, we used red, blue and white LED light as the light source, and the anode and cathode were under irradiation respectively. The result showed that white LED light was an effective factor for the anode, the cell voltage was built up from 34 mv to 60 mv, power density increased up to 2.5 mW/m2, the red and blue light had positive impact on the voltage. At cathode, the voltage was almost on steady stage conditions, and it was fluctuated around 35 mv by oxygen bubbles that were produced by algae. This relatively simple method increased the oxygen reduction rate at a low cost and could be applied to improve the performance of MFC.

Effects of different wavelengths and intensities of visible light on the hatching success of Acartia tonsa Dana eggs

Mass production of copepod eggs in intensive systems has recently been demonstrated to be economically feasible; a few companies producing copepod eggs have been established. It is well documented that water physiochemical variables could significantly influence the hatching success of Acartia tonsa Dana, 1849 (Copepoda: Calanoida) eggs. This information is important to end users in order to achieve a predictable output of nauplii when hatching eggs for live feed production in marine larviculture. The effect of different wavelengths and intensities of light on the 48-h egg hatching success (HS) of fresh and cold-stored (2 °C) A. tonsa eggs were examined in the present study. No correlations were observed between HS and light environment for fresh or cold eggs when they were hatched at wavelengths between 400 and 630 nm and at light intensities of 0.0016, 1, 5 and 16 µE m−2 s−1. Fresh eggs displayed the highest HS and declined with the time of storage. However, eggs being of same age showed a similar HS regardless of the light intensity and wavelength, including when hatched in darkness. We suggest that A. tonsa eggs produced in intensive cultures can be hatched without any concern to the light environment.

The influence of light quality on the accumulation of flavonoids in tobacco (Nicotiana tabacum L.) leaves

Flavonoids are important secondary metabolites in plants regulated by the environment. To analyze the effect of light quality on the accumulation of flavonoids, we performed a rapid analysis of flavonoids in extracts of tobacco leaves using UHPLC-QTOF. A total of 12 flavonoids were detected and identified in tobacco leaves, which were classified into flavonoid methyl derivatives and flavonoid glycoside derivatives according to the groups linked to the flavonoid core. Correlation analysis was further conducted to investigate the effect of different wavelengths of light on their accumulation. The content of flavonoid methyl derivatives was positively correlated with the proportions of far-red light (FR; 716–810nm) and near-infrared light (NIR; 810–2200nm) in the sunlight spectrum and negatively correlated with the proportion of ultraviolet (UV-A; 350–400nm) and the red/far-red ratio (R/FR). By contrast, the content of flavonoid glycoside derivatives was positively correlated with the proportion of UV-A and the R/FR, and negatively correlated with FR and NIR. The results indicated that light quality with higher proportions of FR and NIR increases the activity of flavonoid methyltransferases but suppresses the activity of flavonoid glycoside transferases. While a high proportion of UV-A and a high R/FR can increase flavonoid glycoside transferase activity but suppress flavonoid methyltransferase activity.

The Histopathological Investigation of Red and Blue Light Emitting Diode on Treating Skin Wounds in Japanese Big-Ear White Rabbit.

The biological effects of different wavelengths of light emitting diode (LED) light tend to vary from each other. Research into use of photobiomodulation for treatment of skin wounds and the underlying mechanisms has been largely lacking. We explored the histopathological basis of the therapeutic effect of photobiomodulation and the relation between duration of exposure and photobiomodulation effect of different wavelengths of LED in a Japanese big-ear white rabbit skin-wound model. Skin wound model was established in 16 rabbits (three wounds per rabbit: one served as control, the other two wounds were irradiated by red and blue LED lights, respectively). Rabbits were then divided into 2 equal groups based on the duration of exposure to LED lights (15 and 30 min/exposure). The number of wounds that showed healing and the percentage of healed wound area were recorded. Histopathological examination and skin expression levels of fibroblast growth factor (FGF), epidermal growth factor (EGF), endothelial marker (CD31), proliferating cell nuclear antigen (Ki67) and macrophagocyte (CD68) infiltration, and the proliferation of skin collagen fibers was assessed. On days 16 and 17 of irradiation, the healing rates in red (15 min and 30 min) and blue (15 min and 30 min) groups were 50%, 37.5%, 25% and 37.5%, respectively, while the healing rate in the control group was 12.5%. The percentage healed area in the red light groups was significantly higher than those in other groups. Collagen fiber and skin thickness were significantly increased in both red light groups; expression of EGF, FGF, CD31 and Ki67 in the red light groups was significantly higher than those in other groups; the expression of FGF in red (30 min) group was not significantly different from that in the blue light and control groups. The effect of blue light on wound healing was poorer than that of red light. Red light appeared to hasten wound healing by promoting fibrous tissue, epidermal and endothelial cell proliferation. An increase in the exposure time to 30 min did not confer any additional benefit in both red and blue light groups. This study provides a theoretical basis for the potential therapeutic application of LED light in clinical settings.

Investigation of Growth Rate and Phycocolloid Content from Kappaphycus alvarezii (Rhodophyta, Solieriaceae) under Different Light Conditions Using Vibrational Spectroscopy

&lt;p&gt;&lt;em&gt;Kappa&lt;/em&gt;-carrageenan (&lt;em&gt;K&lt;/em&gt;-carrageenan) is an important phycocolloid which is a major constituent of the cell wall of &lt;em&gt;Kappaphycus alvarezii&lt;/em&gt;. The chemical structure of &lt;em&gt;K&lt;/em&gt;-carrageenan comprises a linear backbone of D-galactose residues linked with alternating α-(1,3) and β-(1,4) linkages which are substituted by one ester-sulphonic group per di-galactose repeating unit. The spectral qualities of light as well as the ambient carbon dioxide concentration, both play an important role in the photosynthetic pathway in plants and this investigation set forth to establish the effect of different wavelengths of light and carbon dioxide supplementation on the chemical structure of &lt;em&gt;K&lt;/em&gt;-carrageenan obtained from &lt;em&gt;K. alvarezii. &lt;/em&gt;Specimens were cultivated under a range of monochromatic light spectra and assessed for chemical composition using Fourier Transform Infrared (FTIR) spectroscopy.The &lt;em&gt;K. alvarezii&lt;/em&gt; control was irradiated with full light spectrum, treatments were carried out using blue (492-455 nm), green (577-492 nm) and red (780-622 nm)light. One experiment was carried out by supplementation with carbon dioxide. Samples were collected after 14 days. The effect of different wavelengths of light on the growth rates of experimental samples was determined. Red light had the most significant impact on the growth rate of &lt;em&gt;K. alvarezii &lt;/em&gt;as compared to those treated with blue light. The FTIR fingerprint of the ground seaweed was found to be identical to that of commercial &lt;em&gt;K&lt;/em&gt;-carrageenan (Sigma). Special emphasis was given to the 800-1300 cm&lt;sup&gt;-1 &lt;/sup&gt;region, which presents several vibrational modes. All the samples produced similar FTIR spectral profiles, suggesting that genes related to the carrageenan biosynthesis are not affected by different wavelengths of light or CO&lt;sub&gt;2&lt;/sub&gt;. The results obtained from FTIR spectroscopy demonstrated that different wavelengths of light and supplementation with CO&lt;sub&gt;2&lt;/sub&gt; have no influence to the chemical structure of &lt;em&gt;K&lt;/em&gt;-carrageenan in &lt;em&gt;K. alvarezii&lt;/em&gt;.&lt;/p&gt;

Effect of different wavelengths of light on laccase, cellobiose dehydrogenase, and proteases produced by Cerrena unicolor, Pycnoporus sanguineus and Phlebia lindtneri.

Three species of white rot fungi: Cerrena unicolor, Phlebia lindtneri and Pycnoporus sanguineus were cultured in two different media under five different lighting conditions: dark, white, red, blue, and green light. Laccase, cellobiose dehydrogenase, and protease activities were examined in the samples. Blue light efficiently boosted laccase synthesis in C. unicolor and P. sanguineus, whereas the highest activities (20 654 nkat/l) of P. lindtneri laccase were observed when this fungus was maintained in green light. On the contrary, the green light allowed obtaining the highest activities of cellobiose dehydrogenase of C. unicolor and P. lindtneri, while CDH of P. sanguineus seems to be dependent on white light. It is clearly visible that differences in protease activities are noticeable not only between the lights variants but also among the media used. However, high proteases activities are correlated with light variants inducing laccase in Lindeberg and Holm medium. Contrary to the cellulose-based medium, where they are weak in light variants that lead to high CDH activities.