UV Light Transmission Research Articles

Hollow-Core Fiber for Single-Mode, Low Loss Transmission of Broadband UV Light

Hollow-Core Fiber for Single-Mode, Low Loss Transmission of Broadband UV Light

Influence of Ti Layers on the Efficiency of Solar Cells and the Reduction of Heat Transfer in Building-Integrated Photovoltaics

This study examined the potential application of metallic coatings to mitigate the adverse effects of ultraviolet (UV) and infrared (IR) light on photovoltaic modules. Titanium coatings were applied on low-iron glass surfaces using magnetron sputtering at powers of 1000, 1250, 1500, 1750, 2000, and 2500 W. The module with uncoated glass served as a reference. The Ti layer thickness varied from 7 nm to 20 nm. Transmittance and reflectance spectra were used to calculate visible light transmittance Lt, UV light transmittance Ltuv, solar transmittance g, and visible light reflectance Lr. The obtained parameters indicated that the thinnest Ti layer (1000 W) coating did not significantly affect light transmittance, but thicker layers did, altering the Lt, g, and Lr factors. However, every sample noticeably changed Ltuv, probably due to the natural formation of a UV-reflective thin TiO2 layer. The differences in fill factor (FF) were minimal, but thicker coatings resulted in lower open-circuit voltages (Uoc) and short-circuit currents (Isc), leading to a reduction in power conversion efficiency (PCE). Notably, a Ti coating deposited at 2500 W reduced the power of the photovoltaic module by 78% compared to the uncoated sample but may protect modules against the unwanted effects of overheating.

Evaporation-Induced Switching from Flocculated to Dispersed TiO2 Nanoparticles in Binary Solvents.

Evaporation in mixed solutions containing both volatile and involatile solvents changes the properties of the binary solvent. We found that evaporating one solvent drastically increased the affinity of the mixed solvent to dispersant molecules and induced a switch from flocculated to dispersed TiO2 nanoparticles (TiO2NPs). We prepared dispersions of TiO2NPs with mixtures of volatile cyclosiloxane (Dx), involatile polar oil, and a dispersant, namely polyhydroxystearic acid (PHSA). Dx is a nonsolvent but the polar oil is a good solvent for PHSA. The dispersions were applied on a quartz substrate, and Dx was evaporated. The original applied films were turbid, in which flocculated TiO2NPs formed network structures. However, as the evaporation of Dx progressed, the drying films became transparent and the network structures of TiO2NPs loosened and disappeared. After the evaporation of Dx, the applied films were transparent to visible light but blocked the transmission of UV light. The flow characteristics of the dispersions also changed. The original dispersions showed shear-thinning but became more Newtonian-like as the fraction of Dx decreased. Generally, particles are concentrated in drying dispersions and become packed or flocculated as evaporation progresses. Our findings show that initially flocculated nanoparticles can be redispersed after evaporating a specific solvent. The effects of different Dxs and compositions on the switch from flocculated to dispersed TiO2NPs and their applicability as sunscreens are discussed.

Preparation of superhydrophobic coatings with excellent durability by synergistic reinforcement of cationic starch and tannic acid

The intrinsic hydrophilicity of sustainable and environmentally friendly biobased materials like starch and its derivatives limits their potential as hydrophobic functional materials. This study presents an eco-friendly and non-toxic method to create coatings with exceptionally high hydrophobicity. Octadecyltrimethoxysilane (ODS) reacts with nano silica (SiO2) through a silane coupling reaction to form superhydrophobic SiO2. The Si-OH groups generated from ODS hydrolysis can undergo a condensation reaction with tannic acid (TA), which is rich in phenolic hydroxyl groups. This enables the hydrophobic silane to bind indirectly with cationic starch (CS), resulting in a stable superhydrophobic CS-based coating. The coating demonstrates significant hydrophobicity (contact angle >170°), excellent UV light transmittance (<4.05 %), self-cleaning properties, prolonged shelf life (over eight months), antibacterial activity, and encapsulation capability. It also shows a separation efficiency exceeding 99 % after 25 oil-water separation cycles and is easily recoverable. The study elucidates the mechanism behind the preparation process and the factors enhancing hydrophobic properties. The research findings suggest that the novel, cost-effective CS/TA/ODS/SiO2 coating offers a scalable solution for superhydrophobic applications and broadens the horizon for green starch use in hydrophobic materials.

Cinnamaldehyde- and nonanal-incorporated polyvinyl alcohol/colloidal silicon dioxide films with synergistic antifungal activities

Biodegradable materials may help solve the problem of environmental pollution caused by conventional synthetic food packaging. Here, various amounts of colloidal silicon dioxide [CSD, 5, 10, and 15 wt% based on polyvinyl alcohol (PVA)] and 1 % SCAN, a 1:1 (v:v) combination of cinnamaldehyde and nonanal, were added to fabricate PVA-based films. Microstructure analyses using atomic force and scanning electron microscopes revealed that the films had uniform CSD dispersion, and the surface roughness rose along with the CSD concentration. The addition of SCAN prevented UV light transmission. In addition, the introduction of CSD enhanced the water-resistance abilities and tensile strengths of the composite films. The PVA/SCAN films exerted remarkable antifungal activities against Aspergillus flavus owing to a synergistic effect between cinnamaldehyde and nonanal. Furthermore, the PVA/SCAN/CSD film, contrasted with the PVA film containing SCAN alone, attenuated the SCAN loss during storage and also continually released SCAN from the film. In peanut preservation, the PVA/SCAN/CSD composite film was superior to the single-element films in antifungal activity, showing decreases of 76.66 % and 85.33 % in the production of conidia and aflatoxin B1, respectively. In conclusion, the PVA/SCAN/CSD composite film with high UV barrier, water-resistance ability, excellent mechanical properties and antifungal activity possesses a promising application potential in food packaging.

Sustainable gelatin-based packaging with nanoemulsified chilli seed oil for enhancing poultry meat preservation: An eco-friendly approach

Utilizing poultry feet, a typically underutilized by-product, we extracted gelatin to fabricate environmentally friendly packaging pouches for the shelf life enhancement of fresh chicken breast cubes. The incorporation of chilli seed oil nanoemulsions, characterized by their particle sizes (61-127 nm) and zeta potential values (-18 to -28 mV), not only contributed to the pouches' structural integrity but also imparted antimicrobial properties. These pouches demonstrated reduced UV light transmittance and controlled color changes in packaged chicken breast cubes, compared to the control samples. Significantly, the pouch-packaged samples exhibited slower pH increase, reduced weight loss (16.2-20.4%), and lower TBARS values, indicative of delayed lipid oxidation and spoilage. Microbiological assessments revealed that the packaged samples effectively restrained microbial growth, staying within safety limits for E. coli and total plate counts, unlike the control samples which exceeded these thresholds. Textural analysis further showed better preservation of the meat's consistency within the pouches. This investigation not only highlights the valorization of food industry by-products in developing sustainable packaging solutions but also emphasizes the efficiency of developed packaging pouches in enhancing shelf-life of fresh poultry meat cubes, thus resonating with the contemporary needs of food processing technologies and consumer acceptance.

Advancing soy protein isolate-ulvan film physicochemical properties and antioxidant activities through strategic high-pressure homogenization technique

Soy protein-based films often exhibit poor properties, including limited mechanical strength, stability, and bioactivity, which hinder their extensive application in the food industry, particularly in edible packaging. To enhance the properties of soy protein-based films, we employed high-pressure homogenization (HPH) to modify the soybean protein isolate (SPI) molecules and sought to cross-link SPI with ulvan polysaccharide, which possesses distinctive bioactivities. The results confirmed that soluble ulvan polysaccharides were incorporated into the cross-linking system through hydrogen bonding. Results indicated that HPH treatment enhanced SPI's solubility and surface hydrophobicity (H0), promoting hydrogen bonding and hydrophobic interactions between SPI and ulvan, as evidenced by ζ-potential and turbidity measurements. Structural and microstructural analyses of both individual SPI and composite films, using FT-IR, XRD, CD and SEM, demonstrated a high compatibility between HPH-treated SPI and ulvan. The incorporation of ulvan reduced the films' tensile strength (TS), but higher pressure significantly improved it (p < 0.05). Post-HPH modification, the films exhibited increased contact angle and swelling capacity (p < 0.05), indicating enhanced hydrophobicity. Higher pressure treatments resulted in more opaque and yellowish films, thereby diminishing ultraviolet light transmission. Thermal stability analyses, via TGA-DSC, showed that U-HSPI films had improved thermal stability compared to pure SPI films. Moreover, ulvan inclusion boosted the antioxidant capacity of SPI films, especially after HPH treatment. Overall, this study confirms that HPH modification substantially influences the properties and activities of SPI-based films, and the complex films based on SPI and ulvan with improved physicochemical and antioxidant properties exhibit a great potential in the food packaging field.

UV Transmission in Prebiotic Environments on Early Earth.

Ultraviolet (UV) light is likely to have played important roles in surficial origins of life scenarios, potentially as a productive source of energy and molecular activation, as a selective means to remove unwanted side products, or as a destructive mechanism resulting in loss of molecules/biomolecules over time. The transmission of UV light through prebiotic waters depends upon the chemical constituents of such waters, but constraints on this transmission are limited. Here, we experimentally measure the molar decadic extinction coefficients for a number of small molecules used in various prebiotic synthetic schemes. We find that many small feedstock molecules absorb most at short (∼200 nm) wavelengths, with decreasing UV absorption at longer wavelengths. For comparison, we also measured the nucleobase adenine and found that adenine absorbs significantly more than the simpler molecules often invoked in prebiotic synthesis. Our results enable the calculation of UV photon penetration under varying chemical scenarios and allow further constraints on plausibility and self-consistency of such scenarios. While the precise path that prebiotic chemistry took remains elusive, improved understanding of the UV environment in prebiotically plausible waters can help constrain both the chemistry and the environmental conditions that may allow such chemistry to occur.

Sustainable papaya plant waste and green tea residue composite films integrated with starch and gelatin for active food packaging applications

This study explores the sustainable utilization of wastes from a papaya plant (papaya peels (PP), papaya seeds (PS), leaf-stem (PL)) and dried green tea residues (GTR) for the synthesis of bioplastics. The dried GTR were individually blended with each papaya waste extract and then boiled in water to get three composite papaya plant waste-green tea supernatants. Potato starch and gelatin-based functional films were prepared by integrating each with the composite papaya waste-green tea supernatant liquid. This work introduces a dissolved organic matter (DOM) study to the field of bioplastics, with the goal of identifying the organic components and macromolecules inherent in the PW supernatants. When compared with the films prepared solely from papaya waste (PW) supernatants, PW-GTR composite supernatant films prevent UV light transmission with superior antioxidant and mechanical properties. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction spectroscopy (XRD), and atomic force microscopy (AFM) were utilized to characterize the starch and gelatin PW-GTR films. Owing to the exceptional antioxidant, UV barrier, and remarkable biodegradable properties of the starch/PW/GTR and gelatin/PW/GTR composite films, make them ideal for use in food packaging applications.

Colour and surface functional properties of wool fabrics coated with gallnut, feijoa skin, and mango seed kernel tannin-stabilised Ag nanoparticles.

In the textile industry, textile materials are dyed and multi-functionalised by multi-step treatments that considerably increase the environmental impacts by increasing water and energy usage along with increasing the generation of volume of effluent. In this work, Ag nanoparticles (Ag NPs) were in situ formed and stabilised with gallnut, feijoa fruit skin, and mango seed kernel-derived tannins, and wool fabrics were coated simultaneously with these Ag NPs in the same bath. The Ag NP treatment produced dark to light olive-brown shades on wool fabrics. The treatment conditions for the treatment with Ag NPs were optimised to achieve the best results. The colour intensity, UV radiation absorption, antibacterial activity, surface electrical resistance, and durability of the treatment to washing were assessed by various methods. The gallnut-derived tannin (GNT)-stabilised Ag NP-coated wool fabrics showed overall the best results including excellent antibacterial activity against various types of bacteria. The treatment was durable to at least 20 cycles of IWS 7A washes (equivalent to 80 domestic washes). For the 0.5% Ag NPs on the weight of fibre (owf) dosage, the UV light transmission through the trisodium citrate-stabilised Ag NP-coated fabric at 365 and 311 nm was 6.37 and 0.95% respectively, which reduced to 1.63 and 0.20% for the fabric coated with GNT-stabilised Ag NPs providing excellent protection against UV radiation. The surface resistivity of wool fabric reduced from 1.1 × 1012 ohm cm-1 for the untreated fabric to 1.1 × 109 ohm cm-1 for the fabric coated with 2.0% owf GNT-stabilised Ag NPs. The stabilisation of Ag NPs with GNT prolonged the wash-durability by reducing the leaching of Ag NPs from the treated fabric. The developed method could be a sustainable alternative to traditional multi-stage treatments conducted in the textile industry with toxic synthetic dyes and finishing agents for the colouration and multifunctionalisation of wool fabrics.

Preparation and characterization of gelatin-carboxymethylcellulose active film incorporated with pomegranate (Punica granatum L.) peel extract for the preservation of raspberry fruit

Active films composed of gelatin and carboxymethylcellulose incorporated with pomegranate peel extract (PPE) were elaborated and characterized. PPE compound identification studies were carried out, and the physicochemical properties of the films and their ability to preserve raspberries under refrigerated conditions (2 °C) were determined. Among the major phytocomponents analyzed by LC-QTOF MS, α and β-punicalagin were identified along with 15 other components. Significant increases in mechanical properties (3.22–8.96 N) and antioxidant activity (18.19–91.15%) were observed when adding PPE (p < 0.05). Increasing the PPE concentration was also shown to reduce UV-light transmission through the films, and color changes occurred at different pH values due to the polyphenol content. The FTIR spectra indicated the transformation of α-helix to β-sheet structures by adding PPE to the films. SEM analysis indicated significant microstructural changes with the incorporation of PPE. The preservation results showed that extending raspberries' shelf life to 15 days was possible. These results revealed the potential of gelatin-carboxymethylcellulose with PPE in manufacturing films with antioxidant, UV-light barrier, and pH-sensitive properties for preserving raspberries.

Evaluation of Optical and Radiation Protection Parameters of High Refractive Index Polymers

The optical properties of the prescription and non-prescription (plano) samples of the MR-8 high index lens were examined by UV/VIS spectrometry. The results showed that the light transmittance of the two MR-8 lens samples examined was over 90%, and the transmittance at the wavelength (~550nm) to which the human eye is most sensitive was 83.437% and 84.602% for the prescription and non-prescription samples, respectively. In terms of quality of vision, it is expected that the visible light transmittance will be high and the ultraviolet light transmittance will be minimal. It is very important that both the prescription and non-prescription organic MR-8 lenses tested have no transmittance below approximately 398nm. This means that this lens material protects against UVA and UVB rays, even though it is uncoated. It is also important to reduce the dose to the lens, which is a radiosensitive tissue. In the study, the mass absorption coefficients of MR-8 and Ormix lens materials in the 0.15-2.00 MeV energy range were calculated using the web-based XCOM programme. LAC, HVL, TVL, MFP, RPE and TF values were calculated from the MAC values obtained. At energies below 0.05 MeV, the maximum MAC value was 0.974 and 4.416 for the MR-8 and Ormix lenses, respectively. The RPE and TF values were 0.807-16.235%, 0.996-0.992% for the MR-8 lens and 0.862-55.233%, 0.448-0.991% for the Ormix lens. The results showed that the photon absorption ability of the Ormix lens is relatively better in the region where the photoelectric interaction is dominant. This research is also important in terms of determining the optical and nuclear radiation parameters of the material used in the manufacture of high index lenses and investigating its effectiveness in reducing the dose to the eyepiece.

Biodegradable PBAT/PLA blend films incorporated with turmeric and cinnamomum powder: A potential alternative for active food packaging

Active packaging made from biodegradable polymers and natural additives appears as an ecological alternative. In addition to having antioxidant activity and enhancing food preservation, it allows mitigating the negative impacts caused by improper disposal. This study pursued to produce biodegradable films based on a polymer blend PBAT/PLA (Ecovio®) using the flat extrusion method. The films were prepared with the incorporation of 5 wt% of powdered turmeric or cinnamon as natural additives. The films obtained, and those reprocessed twice, were characterized in terms of colorimetric, UV light transmittance, water contact angle, water vapor permeability, morphology, mechanical properties, and antioxidant activity. Cinnamon reduced the UV light transmittance and made a surface more hydrophobic. Reprocessing led to greater elongation and maximum load, associated with increased dispersion and distribution, as evidenced in the morphological analysis. The films developed have significant potential for applications in active food packaging, with emphasis on cinnamon-additivated films.

The Effect of Graphene, Silica, And Natural Dust Particles On The Performances of Multiple Types Of Solar Photovoltaic Modules

Desertification and industrial pollution environment can significantly degrade photovoltaic cells performance. Accumulated dust on the surface of a photovoltaic module can partially hinder incident light and consequently degrade optical to electrical energy conversion. Dust properties play a major role in deteriorating solar system performance. Thus, this paper presents extensive investigations on the UV- absorbance, light transmittance and reflectance through an accumulated dust layer. Dust characterization; focusing on its spectral and crystallographic properties of three types of dust (Graphene, Silica, and natural), was carried out to evaluate the degradation rate of the output power for three types of solar PV modules (monocrystalline, polycrystalline, and thin-film). Spectrophotometric analysis was conducted to determine UV light absorbance and light transmittance through the three types of dust. X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) tests were conducted to evaluate the effect of dust crystallinity on light reflectance. A lab-scale setup was used to examine the performances of the three solar PV modules under clean and polluted conditions. Results indicated that Graphene dust exhibits severe UV light absorbance, and its crystalline form increases light reflectance from the surfaces of the modules. However, Silica and natural dust showed a little UV absorbance. Among the three types of the solar PV modules, thin-film panel showed the highest degradation under polluted conditions as compared to the other modules. Therefore, thin film solar module is not recommended for areas with high density of dust.

Fabrication of antimicrobial and high-toughness poly (lactic acid) composite films using tung oil derivatives

Tung oil derivatives are promising alternatives to traditional toxic plasticizers for improving the toughness of poly (lactic acid) (PLA) films. In this study, a tung oil-based quaternary ammonium salt (Q-ETO) was synthesized using a multi-step process involving epoxidation, ring opening, and substitution reactions. PLA based composite films with various amounts of Q-ETO were prepared by solvent casting. The impact of various amount of Q-ETO on PLA/Q-ETO composite films were evaluated with regard to their mechanical properties, hydrophilicity, water vapor permeability, optical properties, thermal stability, antibacterial properties, and leaching properties. The PLA/5%Q-ETO composite film yielded the highest elongation at break (82.52 ± 9.53 %), which was 153.67 % higher than that of pure PLA. All PLA composite films showed an antibacterial efficiency exceeding 90 % against both S. aureus and E. coli. Moreover, the PLA/Q-ETO composite film blocked the transmission of both ultraviolet and visible light while preventing the permeation of water vapor. The addition of Q-ETO only weakly affected the color and thermal stability of the PLA/Q-ETO composite film. Given the numerous advantages of the PLA composite film, it has significant potential for application as a food packaging material.

Effects of filler type and content on mechanical, thermal, and physical properties of carrageenan biocomposite films

This study investigates the influence of various fillers on the properties of carrageenan, a natural polymer derived from red seaweed. Despite its potential for enhanced biocomposite film development, carrageenan faces challenges related to strength. The incorporation of nanoclay into the carrageenan film resulted in a significant increase in film thickness from 0.026 to 0.068 mm. The UV light transmission value for the carrageenan film alone was measured at 30.9 %, whereas films containing 5 wt% of Tetraethyl orthosilicate (TEOS), 3-Aminopropyltriethoxysilane (APTES), and nanoclay exhibited reduced transmission values of 23 %, 18 %, and 1 %, respectively. Notably, the tensile strength of the unfilled carrageenan film was 38.4 MPa, which increased to 38.6, 57, and 60 MPa upon the addition of 3 wt% of nanoclay, APTES, and TEOS fillers, respectively. All fillers contributed to improved tensile strength, with TEOS demonstrating the highest enhancement. The optimal filler content was determined to be 3 wt%. Regarding thermal properties, films containing TEOS displayed higher thermal stability compared to those with APTES, while films incorporating nanoclay exhibited the lowest stability. Findings provide insights into the effects of different fillers on the mechanical, physical and thermal properties of carrageenan films, supporting the development of improved biocomposite materials suitable for application in food packaging.

Farklı Türden Kontak Lenslerin Ultraviyole Işık Geçirgenliğinin Ölçülmesi

Scientific evidence showing the harmful effects of ultraviolet radiation on different ocular tissues has led manufacturers to incorporate UV-blocking monomers into contact lenses. In this study, the spectral and optical properties of contact lenses were analyzed in the ultraviolet and visible light wavelength ranges using the Jasco V-730 UV/VIS spectrophotometer device. The results obtained showed that in the lens samples examined, the light transmittance in the wavelength (550nm) range to which the human eye is most sensitive is over 70% and the maximum value is 72.98% in B contact lenses. The largest cutting edge wavelength value was obtained in the A contact lens as 376 nm. At 550 nm, the absorption spectra were found to be below 0.12. In terms of visual quality, visible light transmittance is expected to be high and ultraviolet light transmittance is expected to be minimal. The degree of damage caused by the amount of ultraviolet light absorption increases. Among the contact lenses with and without ultraviolet-protected monomers, lens A did not transmit the UV-B wavelength region, while lens B transmitted UV-A and UV-B wavelengths. This result showed that the protection of lens A was higher. It is seen that the UV transmittance taken with the phocometer is 45% UV in A lens and 91% UV in B lens. The results obtained by UV/VIS spectrophotometer and phocometer supported each other. The results will contribute to the literature by revealing the importance of UV-protected monomer-containing contact lenses in vision equipment, and by enabling the development and selection of full-protection contact lenses.

Investigation of IR Reflective Coating for Plexiglas Canopy

Purpose: Solar energy is necessary for our global ecosystem. In certain times and parts of the world, the heat generated from the energy of the Sun becomes uncomfortable for us and we need to use additional energy to cool down the generated heat from the Sun. This additional energy usage is detrimental to our environment due to generation of air pollution and use of our natural energy resources. The purpose of this paper is to investigate prevention of undesired generation of heat by the Sun using reflective coating materials.&#x0D; Methodology: In this study, using literature review, Ga doped Zinc Oxide (GZO) is theoretically investigated as a visible light transparent and infrared reflective coating material for the Plexiglas canopy of a solar car. The effect of doping concentration and film thickness is reviewed and discussed. Indium Tin Oxide (ITO) is also studied, using various literature reviews, as an infrared reflective coating material that is transparent in the visible light region. Finally, a spectrophotometer was used to examine the optical properties of a Plexiglas, slide glass, and ITO coated glass, and the results of UV and visible light transmittance measurement of the three materials is presented and discussed.&#x0D; Findings: GZO and ITO films both have high transparency in the visible region of the solar spectrum and high reflectivity to IR radiation starting from 1500 nm to higher wavelengths. None of these films completely reflect the IR radiation with wavelengths in the range of 700 nm to 1500 nm which contribute to generation of heat most. Many factors such as doping concentration and thickness of the films affect reflectivity of the films due to their effect on shifting the plasma frequency. Increasing doping concentration and thickness of the GZO films until a certain threshold improves IR reflectivity of GZO films, but it was not possible to precisely formulate these factors within this study. Reducing the particle size in nanoparticle ITO film improves transmittance of the film in the visible light region and its reflectance in the IR region. The measurement results showed that Plexiglas and glass have a high transparency to visible and near IR radiation.&#x0D; Recommendations: Further investigation and experimentation is recommended to fully understand and formulate doping concentration and film thickness of GZO and ITO to achieve optimal IR reflectivity within the 700 to 1500 nm wavelength region while maintaining visible light transparency. In regards to ITO coating, reduced nanoparticle size is recommended to improve the desired visible and IR transparency and reflectivity of the film. Although GZO and ITO coatings’ doping concentration and thickness to achieve IR reflectivity within the 700 to 1500 nm wavelengths is not well understood in this study, to reduce heat generation they are still recommended as a coating material due to their reflectivity to IR with wavelengths of above 1500 nm which also play a role in generation of heat.

Transmission characteristics of the rough surface scattering channel for wireless ultraviolet communication in a cemented ground scenario.

During non-line-of-sight ultraviolet (UV) communication, as the elevation angle of the transmitter decreases, more UV photons can be scattered by the ground and reach the receiver, and those photons are important components of the received signals. In this paper, a new, to the best of our knowledge, non-line-of-sight noncoplanar UV scattering transmission model taking into account the UV rough surface scattering characteristics is proposed based on the theory of non-line-of-sight multiple scattering UV light transmission and the Monte Carlo method and Kirchhoff's dwell phase method. The proposed model is validated by experiment. Simulation and experiment show that the energy of UV light is mainly concentrated in the direction of mirror reflection after being scattered by the concrete floor, and the energy gets stronger as it gets closer to the mirror reflection direction. In the case of small elevation angle, the photon energy scattered by the ground and received by the receiver must be considered. The path loss obtained by the improved model better fits with experiment.

Advances in Design and Development of Lumi-Solve: A Novel Drug-Eluting Photo-Angioplasty Device.

The Lumi-Solve photo-angioplasty drug eluting balloon catheter (DEBc) may afford safety advantages over current DEBc. Lumi-Solve utilises the guidewire (GW) port and lumen to deliver fibre-optic UV365nm light to the angioplasty balloon which may be problematic. We explore and evaluate alternative Lumi-Solve design options to circumvent fibre-optic use of the GW port and lumen which may enhance efficacy and clinical utility. Effects of guidewire shadowing (GWS) on visible and UV365nm light transmission were evaluated and modelled in-silico. To evaluate the effect of a dedicated intra-balloon fibre-optic port, modified angioplasty balloons and sections of translucent polyethylene terephthalate (PET) GW port tubing were utilised. Investigation of the effect of GWS on chemical and biological photo-activation of balloon surface drug was performed utilising LCMS analysis and inhibition of histone deacetylase activity (HDACi) was measured in human umbilical vein endothelial cells (HUVEC). Parallel fibre-optic and GW port configurations generated a GWS of approximately 18.0% of the evaluable balloon surface area and attenuated both visible and UV light intensity by 20.0-25.0% and reduced chemical photo-activation of balloon surface drug and HDACi by at least 40-45%. Alternative fibre-optic port configurations including a spiral design significantly mitigated GWS effects on UV light transmission. To avoid use of the GW port and its associated complications a dedicated third port and lumen for the Lumi-Solve fibre-optic may be required. To maximize balloon surface chemical and biological photo-activation, non-parallel, intra-balloon, fibre-optic lumen trajectories, including a spiral design may be useful.