Use Of Ultraviolet Research Articles

Study of UV fiber’s mechanical properties

Abstract A number of spectroscopic techniques make use of ultra violet (UV) absorbance and luminescence measurements to characterize materials, for use in medical/pharmaceutical applications, for forensic and sensor applications, and for remote detection or monitoring, especially for hazardous environments. Furthermore, many high-power applications in medicine and industry are looking forward to using UV wavelengths. The UV fiber’s mechanical reliability has become one of the most crucial performances with longer length fiber being used. This paper reviews the researched evolvement of the normal single mode fiber’s mechanical reliability. Based on the standard measure method of the normal fiber, the mechanical reliability of the UV fiber has been researched. The measurement results show the difference of mechanical reliability between the different doping composition UV fibers.

Confinement Of Myosin Motor Activity On Trimethylchlorosilane Surface By Ultra Violet Light Exposure For Nano-Technology Applications

BACKGROUND: The exploration of biomolecular motors for use in nanotechnological applications has generated much interest in the scientific community over the past several years. Although recent progress has been very promising, several requirements have yet to be fulfilled in order for motor proteins to be useful in nanotechnological applications. PURPOSE: is to aid in selective localization of motor proteins to predetermined areas. METHODS: we examine the use of trimethylchlorosilane (TMCS) as a surface material for the in vitro myosin motility assay. Similar to what was seen for nitrocellulose, TMCS coated surfaces supported myosin motility at a variety of myosin concentrations. The velocity of actin filaments and bundles was similar between surfaces and between myosin concentrations. Taken together these data suggest that actomyosin motility is of similar quality on TMCS as on nitrocellulose. To extend these studies, we examined the use of ultra violet (UV) treatment (UVL20 4.5 W, 275 nm) as a means to alter TMCS hydrophobicity. RESULTS: With increasing UV exposure, the contact angle of TMCS coated glass was reproducibly decreased (untreated: 81°, 30 sec: 69.5°, 1 min: 58.25°, 2min: 39.5°, 5 min 24.5°, and 10 min:16.25°). Use of the in vitro motility assay demonstrated that UV treatment was capable of confining myosin motor activity to selected subregions on the micropatterned surface while protein binding studies using fluorescently labeled protein (FITC-BSA) suggested that alterations in hydrophobicity were associated with differences in surface adsorption of protein. CONCLUSION: These data suggest that TMCS patterning may be useful for the selective localization of biomolecular motors. (250 words) (Supported by funds from NSF-EPSCoR Grant 0314742 to MU and NIH Grant027103-1 to EB).

Combined Ozone and Ultraviolet Inactivation of Escherichia coli

The kinetics of Escherichia coli inactivation using ozone and ultraviolet (UV) radiation, separately and simultaneously, was evaluated at 25°C in buffered (pH 6.0, 7.0 and 8.0), demand-free media. While ozone was found to be a stronger disinfectant than UV radiation, using both simultaneously was more effective than using them individually. Inactivation kinetics was pseudo first-order for the three treatment processes, while the disinfection rate was a linear function of the disinfectant dose. The synergism observed in microbial inactivation when the disinfectant processes were combined was illustrated by estimates of kinetic model parameters. This synergy was attributed to the generation of hydroxyl radicals via ozone photolysis. Subsequently, dosage calculations, as based on disinfectant level and exposure time, indicated that the simultaneous use of UV and ozone could substantially reduce their individual doses.

UV protection filters by dielectric multilayer thin films on Glass BK-7 and Infrasil 301

The increasing use of Ultraviolet (UV) light in medicine, industrial environments, for cosmetic use, and even in consumer products necessitates that greater attention be paid to the potential hazards of this type of electromagnetic radiation. To avoid any adverse effects of exposure to this type of radiation, four suitable protection filters were produced to block three UV bands (UVA, UVB, and UVC). The design structure of the required dielectric multilayer filters was done by optical thin film technology using the absorbing property of UV radiation for the substrates and dielectric materials. The computer analyses of the multilayer filter formulas were prepared using Macleod Software for the production processes. The deposition technique was achieved on optical substrates (Glass BK-7 and Infrasil 301) by dielectric material combinations including Titanium dioxide (Ti 2O 3), Hafnium dioxide (HfO 2), and Lima (mixture of oxides SiO 2/Al 2O 3); deposition being achieved using an electron beam gun. The output results of the theoretical and experimental transmittance values for spectral band from 200 nm to 800 nm were discussed in four processes. To analyze the suitability for use in ‘real world’ applications, the test pieces were subjected to the durability tests (adhesion, abrasion resistance, and humidity) according to Military Standard MIL-C-675C and MIL-C-48497A.

ID Card Printing – Is Your Process Secure?

While technology is enabling the production of Optical Variable Devices (OVDs) that can impact the risk of fraudulent ID card replication, the threat of fraudulent ID card issuance within organizations remains a growing trend worldwide.The theme of this presentation is to outline methodologies for reducing the risk of fraudulent ID card issuance. Discussion topics will include the capacity of an issuing organization to track and validate legitimately printed IDs through print imaging technologies. Methods for the prevention of non-authorized printing will also be discussed.In the context of the presentation an array of solution alternatives will be presented that include the use of Ultra Violet (UV) printing and security inks in the print personalization process; printing IDs and tracking ID card issuers covertly; using imaging software to control printing.

Transition metal/UV-based advanced oxidation technologies for water decontamination

This study explores the effect of ultraviolet (UV) light radiation and/or transition metals (M) for the activation of common oxidants (Ox) with the objective of treating recalcitrant organic contaminants in water. Hydrogen peroxide, potassium peroxymonosulfate and potassium persulfate were combined with iron, cobalt and silver, respectively, and/or with UV light (254nm) and were tested for the treatment of 2,4-dichlorophenol (2,4-DCP). Results from our previous studies indicated that these particular transition metals are the best catalysts for the activation of the respective oxidants [G.P. Anipsitakis, D.D. Dionysiou, Environ. Sci. Technol. 37 (2003) 4790; G.P. Anipsitakis, D.D. Dionysiou, Environ. Sci. Technol. 38 (2004) 3705]. From the combined use of UV, the oxidants and the transition metals, four general categories of advanced oxidation technologies were evaluated and compared for the degradation and mineralization of 2,4-DCP. Those were (i) the dark conjunction of each oxidant with its favorable metal activator (M/Ox), (ii) the use of UV alone, (iii) the combination of UV with each oxidant (UV/Ox) and (iv) the use of UV combined with each metal/oxidant systems (UV/M/Ox). In particular, the systems UV/KHSO5, UV/Co(II)/KHSO5 and UV/Ag(I)/K2S2O8 and the sulfate radicals generated thereby have never been tested before for water decontamination, as opposed to the extensively investigated hydroxyl radicals generated by UV/H2O2 and the photo-Fenton. The comparison of the results with respect to the transformation of 2,4-DCP and the extent of organic carbon removal led to the construction of the following order of efficiencies: UV/K2S2O8 > UV/KHSO5 > UV/H2O2 for the UV/Ox processes and UV/Fe(III)/H2O2 > UV/Fe(II)/H2O2 > UV/Co(II)/KHSO5 > UV/Ag(I)/K2S2O8 for the UV/M/Ox processes tested here. All experiments were homogeneous and conducted at ambient room temperature. The relative absorbance of the species participating in the reactions supports the former order of efficiency, since persulfate followed by peroxymonosulfate were proven more photosensitive than hydrogen peroxide. Among the metals tested, only iron species such as Fe(OH)2+ were found to absorb strongly at 254nm and to this is attributed the higher efficiencies obtained with the photo-Fenton reagents.

Evaluating the life cycle environmental performance of chlorine disinfection and ultraviolet technologies

With increasing emphasis on promoting a sustainable ecological future and concern over introducing a toxic chemical in the water, the design of the disinfection process is increasingly leaning toward technologies that destroy the pathogens while balancing the effects of this disinfected wastewater on the population of aquatic biota or a drinking water supply. Since ultraviolet (UV) irradiation is not a chemical additive, it does not leave or produce any by-product toxic compounds in the wastewater, like traditional chlorination and de-chlorination processes do. Therefore, the use of UV does not affect a drinking water supply or the aquatic biota in receiving waters.

A study of the effect of ultraviolet (UV) and vacuum ultraviolet (VUV) photons on the minority carrier lifetime of single crystal silicon processed by rapid thermal and rapid photothermal processing

Minority carrier lifetime is an efficient indicator of defect levels present in the starting material as well as process and equipment induced defects. By employing rapid thermal processing (RTP) and rapid photothermal processing (RPP) as the thermal processing techniques, we have studied the effect of ultraviolet (UV) and vacuum ultraviolet (VUV) photons on the bulk minority carrier lifetime of phosphorous doped and undoped single crystal silicon wafers. For both diffused and undiffused wafers, we have observed an enhancement in the minority carrier lifetime when UV and VUV photons are used in conjunction with the samples processed without the use of UV and VUV photons. The effect of ramp rates on the minority carrier lifetime and the significance of optimized thermal cycles have also been studied in this paper. A possible explanation based on the dependence of diffusion coefficient on the photo spectrum of light source is also given in this paper.

Changing from rapid thermal processing to rapid photothermal processing: what does it buy for a particular technology?

Rapid thermal processing (RTP) based on incoherent light as a source of energy has emerged as an alternate of furnace processing. In recent years, we have demonstrated that in addition to the high heating and cooling rates, quantum photoeffects play an important role in the operation of RTP. The quantum photoeffects can be fully exploited by using an incoherent light source as the source of optical energy (photons with wavelength less than 800 nm) and tungsten halogen lamps as the source of optical and thermal energy. The use of ultra violet (UV) or vacuum ultra violet (VUV) photons along with infrared photons is referred to as rapid photothermal processing (RPP). This paper addresses the issues involved as we move from RTP to RPP. The improved device performance results of diffusion, chemical vapor deposition (CVD), ohmic contact formation and metallization are described in detail. The manufacturing issues like stress, defects, reliability and yield are discussed in the context of RPP and the paper presents potential advantage of RPP for the manufacturing of microelectronics, solar cells, flat panel display and optoelectronics.

Use of UV to reduce particle trapping in process plasmas

The use of ultraviolet (UV) radiation to reduce the negative charge on dust particles and modify force balance in particle traps in processing plasmas is investigated theoretically. Possible photophoresis associated with the UV flux is also discussed. The use of UV to facilitate moving contaminant particles from traps is considered.

High Pressure Capillary Thallium-Amalgam Arc for Use in Ultraviolet

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Aromatic Types in Heavily Cracked Gas Oil Fraction. Combined Use of Ultraviolet and Mass Spectrometry

Aromatic Types in Heavily Cracked Gas Oil Fraction. Combined Use of Ultraviolet and Mass Spectrometry

Elements of the Theory Underlying the Disinfection of Water by Ultra Violet Light

The steadily increasing use of ultra violet for the disinfection of water supplies, large and small, seems to indicate that the art is sufficiently well advanced to warrant a discussion of the theory upon which it is based. This theory, recruiting its hypotheses and proofs from the basic sciences of physics, chemistry, and biology, deals with the nature and general physical properties of ultra violet and with the photoabiotic effects which it is able to produce, so far as any of these are related to the application of ultra violet to water disinfection. It is hoped that an elementary discussion of this nature will be of interest to water works engineers, and that it will be instrumental in dispelling the clouds of mystery which enshroud to so many this most natural of all methods of water disinfection. The advance in our knowledge of the theory of ultra violet is due especially to Schumann, Lyman, and other physicists who investigated the spectroscopy of the ultra violet, and to Bovie and his coworkers, who reported upon its biological activities, while the list of names of those who have been connected with its scientific application to water disinfection includes those of many scores of French, German, and American workers. Radiation. The word light is familiarly associated with the sensation of vision alone. If, however, the electromagnetic waves which produce the sensation of when they fall upon the eye and therefore become post facto or luminous radiations' ' be allowed to fall upon an opaque body, the same may be warmed and the radiations become radiant heat. If, on the other hand, they fall upon a living green leaf or a photographic plate, they may produce changes and thus become or chemical rays. All three names luminous, heat, or actinic radiations may therefore be given to the same wave train, depending upon the