Ultraviolet Ray Irradiation Research Articles

アナターゼ型酸化チタン薄膜の紫外線で発現する光誘起親水性に関する研究

In order to investigate sustainability of hydrophilicity in the dark, life of photo inductive wettability generated by ultraviolet ray irradiation for anatase-type titanium dioxide film was obtained. The films were prepared by using cylindrical magnetron gas flow sputtering (CM-GFS) source with pure titanium pipe target. Irradiation by ultraviolet ray tremendously enhanced wettability for short time. When the time decay of wettability was studied, the photo inductive wetting sufficiently kept the high wetting of anatase-type titanium dioxide (TiOx) film. The life of photo inductive wetting was a week. To discuss the change in surface condition, wettability change was applied for the extended Howkes theory analysis. Although the wettability decay was explained by decrease in the hydrogen bond strength, sustainability of hydrophilicity in the dark on the photo inductive wetting was explained by maintaining the increase of dipole interaction effect. Based on the results, difference between photo catalytic reaction and photo inductive effects were discussed for anatase-type titanium dioxide film.

Comparison of effects of ultraviolet and60Co gamma ray irradiation on nylon 6 mono-filaments

The effect of UV and60Co gamma radiations on the physical and mechanical properties of nylon 6 mono-filaments with different draw ratios has been studied. Specimens were exposed to either up to 25 Mrad of gamma or up to 168 hrs of intense UV irradiation. The results show that nylon mono-filaments exposed to gamma rays, with much higher quantum energy than UV, undergo a larger extent of molecular chain scission. Higher irradiation dose also results in the production of insoluble, macroscopic three-dimensional cross-linked network structure. The amorphous regions with a lower density of cohesive energy (lower molecular orientation) show a higher extent of cross linking reaction whereas amorphous regions with a higher density of cohesive energy (higher orientation) show higher extent of chain scission reaction, irrespective of UV ray or gamma ray irradiation.

Ultraviolet-ray irradiation and degradation evaluation of the sealing agent EVA film for solar cells under high temperature and humidity

Abstract We used ultraviolet-ray irradiation and conditions of high temperature and humidity to study the stability of a compound of a special type of ethylene acetic acid vinyl (EVA) capsule composed of EVA/quartz and quartz/EVA/quartz, focusing on their deterioration over time. The cause of deterioration of the quartz/EVA/quartz was analyzed. It was observed that the quality of transmission of quartz/EVA/quartz increased with a short wavelength light of 250–400 nm, corresponding to the intensity of ultraviolet-rays. However, the transmissivity of EVA/quartz did not increase with a short light wavelength. Cracking and yellowing of EVA films was also seen in part of the experimental sample.

TiO2현탁액에 의한 Brilliant Blue FCF의 광촉매 분해

In a batch reactor, the characteristics of photocatalytic degradation of brilliant blue FCF in titanium dioxide suspension was studied under the irradiation of ultra-violet ray. Photocatalytic degradation in anatase type of TiO<TEX>$_2$</TEX> was more effective than in rutile type of <TEX>$TiO_2$</TEX> below the dosage of 5g. The degradation rate was slightly increased with decreasing initial pH of brilliant blue FCF aqueous solution, but rapidly increased with the addition of oxidant. Potassium bromate acted as more effective oxidant than ammonium persulfate. The photocatalytic degradation rate of brilliant blue FCF was pseudo-first order with rate constants of 0.012, 0.006 and <TEX>$0.003min^{-1}$</TEX> at initial pH 3.1, 5.2 and 7.1 of brilliant blue FCF solution, respectively.

Preparation and photocatalytic performance of anatase-mounted natural porous silica, pumice, by hydrolysis under hydrothermal conditions

A natural porous silica, pumice, was used as a substrate for photocatalytic TiO2. Mounting of anatase-type TiO2 was successfully performed through hydrolysis of TiOSO4 under hydrothermal conditions. Anatase-mounted pumice particles thus prepared were floating and rotating on the surface of water with stirring. Adsorption and photocatalytic performances were examined in methylene blue aqueous solution in the dark and under ultraviolet ray irradiation, respectively. Methylene blue in water could be decomposed rapidly by anatase-mounted on pumice particles. Their photoactivity was evaluated by subtracting adsorbed amount of methylene blue. High efficiency of usage of UV rays for photodecomposition of organic pollutants in water was expected.

Solid Film Device to Visualize UV-Irradiation

Abstract A solid film device capable of visualizing ultraviolet ray irradiation was created using a nanohetero-structured polysaccharide solid containing acid generator, dye and 2-propanol medium.

A case of extensive second degree burn caused by ultraviolet ray irradiation

A case of extensive second degree burn caused by ultraviolet ray irradiation

Influence of Oxidative and/or Reductive Treatment on Human Hair (I): Analysis of Hair-Damage after Oxidative and/or Reductive Treatment

We devised a damaged hair model to confirm hair-damage was caused not only by chemical stress but also by physical and environmental stress. We observed morphological changes (e.g. decreasing cuticle layers, scale lift, hair swelling) in the hair model and analyzed alterations in the hair composition (e.g. cysteic acid, protein elution, melanin granule). We devised oxidative and reductive treatments (e.g. perming, bleaching) as the chemical stresses. We also devised a system for testing physical and environmental stresses. This consisted of ultraviolet ray (UV) irradiation, brushing, treatment with detergent, drying and heating. These factors are believed to cause hair-damage during normal everyday life. Scale lift was observed and this phenomenon was propagated depending on the amount of physical and environmental stress. The amount of exfoliated cuticles and cysteic acid in the cuticles also tended to increase with the progress of the physical and environmental treatments. The tendency was more remarkable with strong chemical treatments. The swelling of the hair, protein elution and the amount of solubilized melanin granule exhibited similar trends. These trends, though, were not as remarkable as those observed in the cuticle layers. Using the damaged hair model that included physical and environmental stresses, we demonstrated that stresses from everyday life, as well as chemical stresses, effected hair damage. These influences were enhanced depending on the degree of chemical treatment. This tendency was more remarkable in cuticle layers than in the cortex and medulla parts.

Influence of Oxidative and/or Reductive Treatment on Human Hair (II): Effect of Hydrophilic Extracts from Rosmarinus officinalis L. on Oxidative and/or Reductive Hair-Damage

To confirm the effects of hydrophilic extracts from Rosmarinus officinalis L. (HER) on oxidative and/or reductive hair-damage, we first estimated the HER antioxidant effect by doing a β-carotene decoloring test. We additionally conducted an analysis of the biochemical parameters, for example cysteic acid or chemiluminescence (CL), and observed the morphological changes (snapping and splitting frequency) after chemical and physical hair treatment. Furthermore, we compared the effect of applying HER with the effect of applying no antioxidant or the effect of a typical hydrophilic antioxidant, ascorbic acid (AsA). HER had a strong antioxidant effect in the hydrophilic radical generation system in the β-carotene decoloring test. However, HER exhibited moderate antioxidant effects in the lipophilic radical generation system. Concerning hair-damage, applying HER suppressed cysteic acid in the hair after chemical and physical treatment more than when no antioxidant is applied. In addition, HER and AsA application also suppressed CL intensity in the damaged hair in the system using 2-methyl-6-(4-methoxyphenyl)-3,7-dihydroimidazo[1,2-a]pyrazin-3-one hydrochloride (MCLA). However, HER only exhibited a tendency for CL reduction in damaged hair when we induced CL with short time irradiation of ultraviolet rays (UV) without chemical reagents. Furthermore, HER and AsA suppressed the snapping and splitting frequency in the hair, and the suppression level of HER tended to be stronger than that of AsA. HER demonstrated the antioxidant effect in a hydrophilic radical generation system. Furthermore, HER could prevent oxidation and morphological changes in damaged hair that was subjected to oxidative and/or reductive treatment, such as perming and bleaching, as well as physical treatment, which is postulated to cause hair-damage in daily life.

Decomposition of Oxalate in Low-level Liquid Waste Using UV Irradiation

An application of ultraviolet ray (UV) irradiation for the decomposition of oxalate in low-level liquid waste's (LLLW's) including transuranium nuclide was investigated. The decomposition properties of oxalate are studied in various simulated LLLW's which basically contain U(VI) and 3M NaNO3. Batch experiments have revealed that the decomposition rates were increased with a decrease in the concentration of HNO3 in the sample solutions. It has been also found that U(VI) in LLLW's enhanced the decomposition, and that no decomposition was observed in a basic solution containing Na2CO3. An optimum solution condition to decompose oxalate in LLLW's is expected to be 0.05M HNO3. UV was also irradiated in solutions containing 3M NaNO3 without U(VI) and HNO2 has been found to be a decomposing species of oxalate. UV irradiation will be a promising method for the decomposition of oxalate in LLLW's.

The irradiation studies on diamond-like carbon films

Diamond-like carbon (DLC) films have been deposited on glass substrates using radio-frequency (r.f.) plasma deposition method. γ-ray, ultraviolet (UV) ray and neutron beam were used to irradiate the DLC films. Raman spectroscopy and infrared (IR) spectroscopy were used to characterize the changing characteristics of SP 3C–H bond and hydrogen content in the films due to the irradiations. It showed that, the damage degrees of the γ-ray, UV ray and neutron beam on the SP 3C–H bonds are different. Among them, the damage of γ-ray on the SP 3C–H bond is the weakest. When the irradiation dose of γ-ray reaches 10×10 4 Gy, the SP 3C–H bond reduces about 50% in number. The square resistance of the films is reduced due to the irradiation of UV ray and this is caused by severe oxidation of the films. Compared with that of the as-deposited one, the IR transmittance of the films irradiated by both γ-ray and neutron beam is increased to some extent. By using the results on optical gap of the films and the fully constrained network theory, the hydrogen content in the as-deposited films is estimated to be 10–25 at.%.

Redox Control of T-Cell Death

equilibrium of levels of reactive oxygen species (ROS) and antioxidants, might physiologically regulate both cell activation and cell death induction in normal T cells during their development in the thymus and immune response in the peripheral lymphoid organs (10, 11). A low level of ROS is normally produced in cells during respiratory chain chemical reactions in mitochondria, and the cellular ROS level may be increased during cell–cell interaction through binding of inflammatory cytokines to their receptors or exposure to extracellular ROS that are produced by inflammatory cells, including antigen-presenting cells (APC). Exposure to oxidative chemicals including heavy metals from polluted environments, ultraviolet ray irradiation, microbial infections, or genetic abnormality in the antioxidant system may induce an abnormal increase in ROS level/oxidative stress in T cells. Oxidative stress-linked unusual intracellular signaling can induce T-cell-based immunodeficiency and allergic and autoimmune diseases potentially due to loss of regulatory T cells or T-cell-oriented neoplastic diseases. Use of antioxidants such as N-acetylcysteine (NAC) and thioredoxin (Trx) may be effective for treating some of these oxidative stressinduced T-cell disorders. This forum aimed to cover (a) basic understanding of the signal-transduction cascade for T-cell death during normal T-cell development and of the potential involvement of redox-linked mechanisms in the cascade, (b) molecular pathogenesis of abnormal T-cell death induced by environmental oxidative elements, microbial infections, or genetic abnormalities, and (c) therapeutic aspects of antioxidants for revising abnormal T-cell death.

Fabrication of Refractive Index Profiles in Poly (Methyl Methacrylate) using Ultraviolet Rays Irradiation

We demonstrated that the refractive index of poly(methyl methacrylate) (PMMA) increased by simple ultraviolet rays irradiation. The index change, +1.0% was due to the change of chemical structure including elimination of the carbonyl group, followed by olefin formation, which were determined by Fourier-transform infrared rays and UV absorption spectra. A refractive index profile for 15-µm-thick PMMA was realized by irradiation for 4 h. Therefore, it is considered that the graded index (GI) profile of PMMA can be applied to microdevices such as a microspherical lens, single-mode waveguide and so on.

25.1: Improvement on Longevity of Blue Phosphor for PDP Applications

AbstractImprovement in longevity of blue phosphor (Eu2+‐activated barium magnesium aluminate, call as BAM) is investigated for the application of color plasma displays. It is clarified that the properties of phosphor deterioration caused by the irradiation of vacuum ultraviolet rays are dependent on the substituted elements for the specific part of the BAM. The longevity of the modified BAM is longer than that of the conventional one by twice or more by means of the substitution of In, Lu or Sc.

The effects of radiation on (1,3,5 - triamino - 2,4,6 - trinitrobenzene) TATB studied by time-of-flight secondary ion mass spectrometry

Highly Charged Ion (HCI) Time-of-Flight (TOF) Secondary Ion Mass Spectrometry (SIMS) has been employed to analyze the changes in the surface composition of TATB caused by low energy electron, ultraviolet, and Gamma ray irradiation. Comparisons are made between canary yellow (not irradiated) TATB and TATB that has been “greened” by exposure to radiation. We ascribe the color change from yellow to green to a loss of oxygen. Another striking aspect of this study is the presence of a feature at m/z = 30 (NO+) for highly charged ion SIMS, which does not occur in singly charged ion TOF SIMS.

Evaluation of calcification in porcine valves treated by ultraviolet ray and glutaraldehyde

Porcine aortic valve, of which tissue structural collagen matrix is cross-linked by glutaraldehyde (GA) to enhance mechanical property, is widely used in clinics, but gradual calcification occurs after implantation. Cross-linking the valve by 24 h of ultraviolet (UV) ray irradiation that induces collagen fibrous cross-link resulted in less calcium deposition than GA-pretreated leaflets. After 3 days, calcium level in GA-treated leaflets was distinctively higher than in leaflets cross-linked by UV irradiation for 24 h and in the non-treated control leaflets. The exposure time of UV irradiation was not significantly correlated with the extent of calcification. In all the test groups, molar [Ca]/[P] ratio gradually decreased as time went by, and UV-irradiated and control leaflets demonstrated molar [Ca]/[P] ratio close to apatite as the predominant mineral phase and GA-treated leaflet reached the similar molar ratio after 30 days. In animal experiment, the leaflet treated by UV irradiation demonstrated a stable surface without calcification after 2 months of implantation.

光照射下における微量の高分子量アミンを含むジヘキシルスルフィドによる塩酸溶液からの白金（ＩＶ）の抽出

Extraction of platinum (IV) from hydrochloric acid solutions by using dihexylsulfide (DHS) containing micro amount of trioctylmethylammonium chloride (TOMAC) was investigated under irradiation of light. Although the complex of Pt (IV) with DHS is not formed by the extraction, on this extraction system, Pt (IV) was extracted quantitatively by DHS because (TOMA)2PtCl6 complex activated by irradiation of ultraviolet rays acts as catalyst. The stoichiometric composition of the DHS complex formed in the organic phase was deduced to be PtCl4DHS. Therefore, the following equilibrium equations are proposed: PtCl62 -(aq) + 2TOMAC (org) ⇔ (TOMA)2PtCl6(org) + 2Cl- (aq) (TOMA)2PtCl6(org)→hv(TOMA) 2PtCl6*(org) (activated complex) (TOMA)2PtCl6*(org) + 2DHS(org) ⇔ PtCl4 · 2DHS(org) + 2TOMAC(org) . In the equilibrium reactions, it was found that Pt (IV) in the complex is not reduced to Pt (II). The examination of diluent effects proved that aromatic diluents with electron-donating groups, such as m-xylene and toluene, promote the activation of TOMAC-Pt (IV) complex, whereas aromatic diluents with electron-accepting groups, such as chlorobenzene and nitrobenzene, and aliphatic diluents, such as hexane and dodecane, suppress that activation. Furthermore, it was found that from the examination of effects of high molecular-weight amine, the catalytic effect of amine-Pt (IV) complexes depends on their activated degree by irradiation of ultraviolet rays, which is promoted by electron-donating groups of amines, and ability of replacement between the chlorine atoms coordinated to Pt (IV) in the activated complex and DHS, which is affected by steric hindrance of amines.

B113 光防食法による原子炉構造材の腐食緩和

Hydrogen water chemistry and Noble metal chemical addition were applied to actual BWR plants to protect structural materials from IGSCC so far. The important parameter of the susceptibility of IGSCC is the corrosion potential of the materials and the recommended value to mitigate IGSCC is reported as -230mV vs. SHE. In this paper, we discussed the other method to lower the corrosion potential below -230mV vs. SHE. Some n-type semiconductors are excited by photons irradiation and generate photoelectric current. The stainless steel coated with the semiconductor, therefore, has some possibility of shifting the corrosion potential in the negative direction under the photons irradiation. From the laboratory measurements under ultraviolet rays irradiation, the corrosion potential of stainless steel coated with TiO_2 shifted in the negative direction by a few hundred mV. Evaluation of photon flux produced by Cherenkov radiation in the BWR are also carried out and the corrosion potentials of the stainless steel coated with TiO_2 are estimated.

509 二円板間の非軸対称流れの可視化と画像処理(GS-6 粒子・燃焼・流動解析)

In this study, we investigated experimentally the flow between two co-rotating disks with narrow spacings, enclosed by a stationary shroud at the circumference. By flow visualization with aluminium flakes in a water tank, indented shapes of the central core can be observed, and the flow can be classfied into six modes according to the core shapes. We developed a visualization technique with spherical perticles and irradiation of ultra-violet rays for observation of secondary flows. As spherical perticles, we use the bridged polystyrene perticles coated with luminous paint yellow. The equipment has a glass top. PIV analysis of visualizated photos reveals vortical structures in the secondary flow.

Morphology of Polypropylene and Tree Initiation

The morphological aspect of a polypropylene (PP) sample is investigated using an X-ray diffractometer, differential scanning calorimetry (DSC) and an infrared (IR) spectrophotometer. It is found that the samples with spherulite used in this study are composed mainly of the γ-form and a small amount of the α-form, and that the sample without spherulite is composed of a pseudohexagonal phase. The effect of morphology, oxygen and ultraviolet ray (UV) irradiation on tree initiation, and the influence of morphology on space charge are also studied. It is found that space charge storage becomes more difficult and that tree initiation voltage becomes higher with an increase of crystallinity and crystallite size of PP. In the presence of oxygen, tree initiation is attributed to both the accumulation of space charges and the reaction of free radicals with oxygen, while tree initiation is only attributed to the accumulation of space charge in the absence of oxygen.