Mercury Vapor Quartz Lamp Research Articles

Photocatalytic redox processes in aqueous ethanol solutions of mixed cobalt cyanide complexes

Abstract Anaerobic aqueous ethanol solutions of pentacyanocobaltate(II) or mixed complexes of cobalt(II) with cyanide and ehtylenediamine yielded an initial ratio of 1:1 hydrogen and acetaldehyde upon irradiation with a high pressure quartz mercury vapor lamp. In solutions containing ethylenediamine the yield of acetaldehyde was much less. The relative amount of acetaldehyde present decreased during the irradiation which control experiments showed was due to nonphotochemical reactions. The cobalt complexes are truly catalytic with the moles of hydrogen produced many times greater than possible from the nonphotochemical reaction of pentacyanocobatate and water. The identities of the precipitates which appeared during the course of the photocatalytic process have been investigated.

Formation and Decomposition of Ozone by Ultraviolet Rays. III. The Influence of Dichlorodifluoromethane on the Formation and Decomposition of Ozone.

The influence of dichlorodifluoromethane (freon 12) on the formation and decomposition of ozone by ultraviolet rays irradiated from a low pressure mercury vapor quartz lamp has been studied. The lamp used in this study was cylinder shaped 15 W and its main spectral lines were 184.9 nm and 253.7 nm. Freon gas was supplied to the annular middle space of a triple structure pipe that had the lamp in its center. Then, with ultraviolet rays irradiating from the lamp, the relationship between chlorine concentration and freon flow rate was examined. Likewise, air with a small amount of freon gas was supplied to the middle space. The intensity of ultraviolet rays (184.9 nm) after passing through the freon layer was also examined. In a further experiment, freon gas was supplied into the middle space and air with ozone whose concentration was kept constant (10 ppm) was supplied to the annular outside space of the pipe. Then, with ultraviolet rays irradiating from the lamp, the relationship between the decomposition ratio and the gas flow rate was examined. The following results were obtained : (1) Ozone is not decomposed by freon alone. (2) Freon is quite able to pass through 253.7 nm wavelength ultraviolet rays, but it hinders the formation of ozone by easily absorbing 184.9 nm wavelength ultraviolet rays. Ozone was not formed when air was mixed with freon gas of over 0.9 vol%. As the freon flow rate decreased, the formation rate of ozone gradually increased, up to 90% in the case of 0.025 vol%. (3) Freon absorbs 184.9 nm wavelength ultraviolet rays, and part of it forms chlorine after being decomposed. The highest chlorine concentrations recognized, in the case of a 0.11 l/min freon gas flow rate, was 900 ppm. The chlorine concentration produced was in proportion to the ratio of freon in the air. (4) After passing through the freon layer, 253.7 nm wavelength ultraviolet rays are able to decompose ozone without hindrance. That is to say, freon itself does not affect the decomposition of ozone by these ultraviolet rays.

石英製低圧水銀ランプにおける酸素のオゾン化 (3)

石英製低圧水銀ランプにおける酸素のオゾン化 (3)

Formation and Decomposition of Ozone by Ultraviolet Rays. II. The Influence of Temperature on the Formation and Decomposition of Ozone.

The influence of temperature on the formation and decomposition of ozone by ultraviolet rays from a low pressure mercury vapor quartz lamp was studied. The main spectral lines for the lamp used in formation were 184.9 nm and 253.7 nm, and those used in decomposition were 253.7 nm. The lamps were cylinder shaped, and were 10 W. In the formation experiment, the temperature was changed from 55°C to 550°C (eleven levels), keeping the relative humidity constant. Ozone concentration initially increased, then decreased, as the gas flow rate decreased. During this process, the reversing zones at each temperature were recognized. The concentration decreased as the temperature rose, and the tendency was notable at higher temperatures. When the gas flow rate was low at 0.3 l/min or less, the ozone concentration was low, and it began to decrease greatly at about 200°C. It was extremely low at about 450°C. When the gas flow rate was high at 0.5 l/min or above, the ozone concentration was low, and remained constant up to about 200°C, thereafter decreasing greatly. It was extremely low at about 450°C. In the decomposition experiment, keeping the relative humidity constant, the reaction temperature was changed from 55°C to 275°C (eight levels). The differences between the heating decomposition ratio with and without irradiation by ultraviolet rays were measured. The heating decomposition reaction was recognized at around 100°C, and the decomposition ration rose as the gas flow rate decreased when the temperature was kept constant. The ratio also increased with increase in temperature under constant gas flow rate. It was about 70% at 250°C, 1.0 l/min. Data were obtained on temperature and decomposition ratios at various gas flow rates. The decomposition ratio difference increased as the temperature decreased when the rate of gas flow was unchanged, and also increased with decrease in the gas flow under constant temperature. Above a temperature of 250°C, the decomposition reaction of ozone was advanced mostly by heat. That is, the amount of irradiated ultraviolet rays was almost irrelevant.

石英製低圧水銀ランプによる酸素のオゾン化 (4)

石英製低圧水銀ランプによる酸素のオゾン化 (4)

Ozone decomposition by ultraviolet ray. The relationship between the starting ozone concentration and decomposition ratio.

Ozone decomposition capacity by ultraviolet ray from a low pressure mercury vapor quartz lamp was studied in order to purify the exhaust gas of photo oxidation apparatus. The lamp used in the experiments was made from a conventional quartz tube. A main spectral line is 253.7 nm in cylinder shaped 8 W lamps. Spectral lines of 200 nm or under are cut. By supplying the air containing constant concentration of ozone into an annular space of a double pipe structure, the relationship between the concentration of residual ozone and gas flow rate (0.025-10 l/min) were examined. In the measurement the starting concentration of ozone was changed into eight degrees (1, 3, 5, 7, 10, 30, 40, 75 ppm), keeping the exposing length of the lamp and the width of the annular space constant (105, 31 mm) in consideration of the influence on decomposition. In each starting ozone cencentration, when the flow rate was brought down, ozone began to decompose rapidly and then disappeared completely. In the case of high concentration, it began to decompose at a small flow rate, and the decreasing ratio was bigger than that of low concentration. In each concentration the relative formula between supplied gas quantity and the decomposition ratio on the log paper was obtained.

石英製低圧水銀ランプによる酸素のオゾン化 (2)

石英製低圧水銀ランプによる酸素のオゾン化 (2)

石英製低圧水銀ランプによる酸素のオゾン化 (1)

石英製低圧水銀ランプによる酸素のオゾン化 (1)

Current concepts in ultraviolet carcinogenesis.

The relationship between sunlight and cutaneous malignancy has been recognized for almost a century. Unna (1) is generally credited with first describing this association; others followed shortly thereafter (2, 3). Hyde (3) in 1906, also recognized the role of pigmentation in the relative protection of pigmented races from skin cancer. Findlay, in 1928, was able to induce the production of skin cancer in albino mice with radiation from a quartz mercury vapor lamp (4). He also noted that application of tar to the skin of the mice shortened the exposure time necessary to induce tumors. In recent years substantial progress in understanding the pathophysiology of ultraviolet- induced skin cancer has been made. Furthermore, considerable epidemiologic and experimental evidence linking ultraviolet radiation and cutaneous malignancies has been obtained. The purpose of this review is to summarize these data.

Duration of Phosphorescence II

Phosphorescence of calcite and fluorite, exposed for a few minutes to 2537° ultraviolet light from a low-pressure cold quartz mercury vapor lamp, persisted for 18 years. Emission was detected by placing the phosphorescing minerals on black-and-white and Kodachrome film, to obtain “phosphorographs” of the glowing areas. The rate of emission depends on temperature; the color of the phosphorescence has not changed; these confirm the results of other tests that prove that radioactivity is not involved. The patterns of growth of a crystal, and changes of its environment during formation, are clearly shown by the variegated colors in its phosphorograph.

11—THE EFFECT OF COPPER AND IRON ON THE PHOTODEGRADATION OF COTTON

The depolymerization of cotton yarn irradiated with the quartz mercuryvapour lamp was found to be inhibited by both iron and copper, nominally present as hydroxides. On irradiation behind Pyrex glass, which absorbs light of wave-length less than 3000Å, iron again inhibited the reaction, but copper showed a slight positive catalytic effect. In the presence of small amounts of alkali, copper-impregnated yarn degraded extremely rapidly, but the process was scarcely affected by light and appears due simply to alkaline autoxidation. In preliminary experiments, it was found that (1) iron hydroxide can be precipitated in cellulose in a finely divided form, whereas copper hydroxide apparently gives only a coarse opaque deposit; and (2), of fourteen metallic oxides irradiated in aqueous suspension by ultra-violet light, only zinc oxide gave rise to the presence of hydrogen peroxide in the water.

Oxidation of Carbon Monoxide and Methyl Alcohol photosensitized in the Gas Phase by Zinc Oxide

THE well-known photosensitizing action of zinc oxide in oxidation reactions, where oxygen was considered to be the reactant photoactivated in the process and the sensitivity of certain gases in affecting and being affected by the concentration of holes or electrons in semiconductor catalysts led us to examine the possibility of carrying out the photocatalysis of carbon monoxide and methyl alcohol oxidations in the gas phase, the latter giving rise to the former as a secondary phase in the oxidation. This has been done in a dynamic reaction system containing zinc oxide (sulphur content = 0.01 per cent) supported on a quartz frit inside a quartz reaction vessel through which purified oxygen at atmospheric pressure saturated with methyl alcohol vapour at 20° C. (pMeOH = 95.2 mm.) was passed continuously. When the zinc oxide was subjected to radiation emitted from an a.c. 220-V. 2.4-amp., high-pressure quartz mercury vapour lamp kept parallel to the layer of zinc oxide powder on the quartz frit at a distance of 5 cm. the photocatalytic oxidation of methyl alcohol could indeed be induced readily at temperatures ⋝ 70° C. In the absence of irradiation, the oxidation of methyl alcohol catalysed by zinc oxide under identical conditions was observed at and/or above 250° C. only.

Preparation of ultra-violet fluorescent photographs of steroids.

A NUMBER of methods have been used to record photographically the fluorescence of various substances present on paper chromatograms when excited by ultra-violet light. Markham and Smith1–3 used a system consisting of a quartz mercury vapour lamp and a set of two filters containing chlorine gas and a solution of NiSO4.7H2O and CoSO4.7H2O, respectively. Bernasconi, et al.4 used a mercury vapour lamp, a red-purple filter, a cobalt sulphate and nickel sulphate filter, and a 3 mm. thick piece of ‘Plexiglass’. Abelson5 used an ultra-violet hand lamp with a Kodak 2A gelatin filter enclosed in glass plates.

Protection from sunlight in vitiligo.

The occurrence of carcinoma in areas of vitiligo is extremely rare. Its occurrence has never been recorded at the University of Oklahoma where an average of 200 new skin cancers a year are seen. Some protection against ultraviolet irradiation other than melanin must exist in these patients. Finsen¹as early as 1900 suggested that the development of hyperkeratosis might afford protection. Lovisatti,²Guillaume,³and Wirth⁴later demonstrated the increased tolerance to ultraviolet light in vitiliginous and other patients. In 1930, Miescher⁵showed microscopically the hyperkeratosis which occurs upon exposure to ultraviolet light. Comparative measurements of the keratin response in vitiliginous and pigmented areas have never been recorded. Accordingly, the following study was undertaken. <h3>Method</h3> Seven patients with vitiligo were studied. All presented symmetrical depigmentation of the extremities. In each patient, an erythema dose of ultraviolet light from a hot quartz mercury vapor lamp was administered

Study of the vibration spectra of methacrylic acid derivatives containing group IV elements

1. Raman and IR spectra of silicon, germanium, and tin methacrylates were obtained. 2. The -o-m-(M-C, Si, or Ge) bond is covalent in carbon, silicon, and germanium methacrylates; tin methacrylates are ionic compounds. 3. Triethylgermanium methacrylate polymerizes, when exposed to radiation from a quartz mercury vapor lamp, by means of C=C bonds, possibly with simultaneous interchain reaction between carbonyl groups and metal atoms.

Erythema and tumor formation in methoxsalen-treated mice exposed to flourescent light.

There has been considerable concern over the possibility of injury to tissues and eyes following prolonged exposure to fluorescent lamps in view of the energy output of these lamps in the longer ultraviolet spectrum. 1 Nevertheless, there has been no direct evidence, up to this time, of harm to normal eyes or skin resulting from fluorescent lighting. 2 Recently, it has been reported that exposure to this type of lighting may produce polymorphic light-sensitive eruptions. 3 Kline and Rusch 4 have reported that albino mice placed under fluorescent lights four to six hours a day, six days a week, for one year developed no signs of erythema or neoplastic changes of the skin. Griffin et al., 5 studying the effects of fluorescent light in conjunction with quartz mercury vapor, found that albino mice exposed to the total energy of quartz mercury vapor lamps and subsequently housed under fluorescent light developed

A Stady of Eye Complaints Produced by Ultraviolet Radiation from Fluorescent Lighting

Concerning the studies of eye complaints produced by ultraviolet radiation from fluorescent lighting, there have been both positive and negative conclusions.Quite recently in Japan, Dr. Otsuka claimed that 2 patients suffered from diffuse superficial keratitis produced by ultraviolet radiation from fluorescent lights. On the other hand, Dr. Hamano reported that the quality and the quantity of ultraviolet radiation between 3100-4000 Angstrom from fluorescent lights were not harmful to the human eye.In order to investigate these opinions more carefully, we tried some experiments in co-operation with the Fifth Busines Section of the Matsushita Electric Industrial Co.Experiment 1: Spectro-photometry and measurement of the penetration ratio through a fluorescent glass. tube-wall coated with fluorsscent substances from ultraviolet radiation.Ultraviolet radiations shorter than 3126 Angstrom do not pass through the wall of the glass tube, but slightly longer radiations do. Of the radiations between 3126-3132 Angstrom, about 10% pass through the glass wall.Experiment 2: Measurement of the quantity of ultraviolet radiation.Using the Keller form of the Bering-Meyer method, we measured quantitatively the ultraviolet radiation of: the fluorescent light, the high-pressure mercury-vapor quartz lamp, sunlight, and the daylight radiation falling on the surface of the desk in a room.We found the desk-surface radiation to be nearly the same as that given off by a fluorescent light of about 10-20cm. distance (especially when approximating 20cm.) (cf. the table)Experiment 3: As to whether electrical ophthalmy will or will not occur on the eyes of rabbits and/or human adults by ultraviolet radiation.4 female adult rabbits (1 albino and 3 of dark color) were used by applying the fluorescent light to the cornea at a distance of 3cm. over a period of 3 hours.3 men, aged 23, 24, and 39 resp, and 3 women, aged 19, 22 and 27 resp., were used. All were free from pathological symptoms. Only the right eye in each case was used, leaving the left eye free asa control_ To the eye, with the tube touching the eyelash, a 20W Daylight fluo escent light was applied in five cases (yielding a light intensity of 5000 lux), and a lOW Daylight fluorescent light in one (yielding a light intensity of 8000 lux ; this increase rather than decrease in this case was dueto high brightness). This experiment lasted 1 hour.Result: Immediately after the cease of application, 1 man (aged 38) and 2 women (aged 22 and 27) felt a drying sensation which continued from 30' to 1 hour. All cases (rabbits and human adults) were given both a slit-lamp examination and a fluorescein test 3 hours after the experiment ; these examinations were repeated 20 hours after the experiment.The findings in all cases were negative.Conclusion1. The ultraviolet radiation given off by fluorescent lighting is longer than 3126 Angstrom and so is not injurious to the human cornea.2. According to Birch-Hirschfeld & Hoffmann, Triimpy, Vogt, Kinsey, et al, wave lengths shorter than 3100 Angstrom are harmful.3. It is generally recognized that wave lengths shorter than 3100 Angstrom do not penetrate the glass-tube-wall except in negligible amounts.4. Daylight 20W fluorescent lights at 20cm. distance is e-Tuivalent in ultraviolet radiation to the amount of summer daylight ultraviolet radiation coming in through a closed glass window facing north on the desk.5. The human eye is not likely to be exposed to an intensity of 5000-8000 lux (to the eye, with the tube touching the eyelash) over the 5-10 hour period that fluorescent lighting may be used6. Fluorescent desk lamps are usually 10-30cm. away from the cornea and fluorescent ceilling lamps are over 1-2m. distant. Therefore, the intensity, decreasing by the square of the distance, would be negligible.

Influence of Several Variables Encountered in Photochemical Work upon the Intensity of Light of λ 254 mμ Produced by a Quartz Mercury Vapor Lamp of the Low Pressure Type Operating in Water at 0 to 95°1

Influence of Several Variables Encountered in Photochemical Work upon the Intensity of Light of λ 254 mμ Produced by a Quartz Mercury Vapor Lamp of the Low Pressure Type Operating in Water at 0 to 95°¹

The Action of Light on Calcium Alginate Rayon

The absorption spectrum of calcium alginate shows no bands, but a rapid rise in absorption with decreasing wavelength between 2400 and 2260 A. In consequence, tho full radiation of a quartz mercury–vapour lamp has been used in studying the action of light on calcium alginate rayon. When single filaments were irradiated in air at different relative humidities, tho tenacity, measured at 65% R. H. and 22. 2°c, was found to decrease only slightly with rise of relative humidity from 5 to 95%, the tenacity retained after exposure being 75. 7 and 68. 4%, respectively, of tho original tenacity. Tn agreement with this observation, severe degradation was found to be possible in air, nitrogen, and oxygen after intensive drying for periods up to 201 days. It must be concluded, therefore, that neithor oxygen nor water vapour is essential to degradation, though the rate at which it occurs is increased slightly by tho presence of water.

Photoconductivity of Naphthalene and Anthracene

RECENT studies1 of the mobility ('metallic' character) of the unsaturation electrons within molecules containing conjugated double-bond systems suggest that solid conjugated compounds should exhibit the phenomenon of photoconductivity, provided that the unsaturation electrons can acquire enough energy to penetrate the potential barriers between adjoining molecules in the crystal lattice. Photoconductivity has, in fact, been observed in proteins2 and in certain dyes3. We have found that both naphthalene and anthracene, when melted and allowed to solidify between two platinum electrodes about 0·5 mm. apart, show weak photoconductivity when exposed in vacuo to the unfiltered radiation from a quartz mercury-vapour lamp. With applied voltages between 50 and 360, the photocurrents are detectable with a good galvanometer. They are of the order of magnitude of 10-8 amp., and are superimposed on a rather variable dark current. As in the case of dyes3, the photocurrents are quenched if air is admitted to the system.