J. of IEIJ Vol.87, No.2

The Abstracts of the Papers
J.Illum. Engng. Inst. Jpn. Vol. 87, 2003

Comparative Research on the Influence of Various Fluorescent Lamps on Discoloration of Fabrics Dyed with Natural Dyes
—Evaluation by Equal Illuminance—
Maiko SHIMODORI, Kohtaro KOHMOTO and Masako SAITO

 The degree of discoloration of dyed fabrics irradiated by using the three kinds of20-watt tubular type fluorescent lamps having different spectral irradiance distribution where the distance between the lamp and the samples was kept constant in order to give equal radiation energy(irradiance)to the samples was previously reported.In this research,the effect of the optical radiation on the discoloration of dyed fabrics under equal level of illuminance(500 lx)on samples using the three kinds of fluorescent lamps (D₆₅, W,NU)and the eight kinds of dyed fabrics was investigated. The following results were obtained.

(1) The order of discoloration degree was D₆₅>W>NU. On dyed fabric, differences in each mordant and each colorant especially were recognized.
(2) The discoloration reduction effect of the NU lamp compared to the D₆₅ lamp and W lamp was33% and 9%, respectively.
(3) The discoloration reduction effect of the NU lamp compared to the D₆₅ was 18% for equal irradiance and 33% for illuminance.The equal irradiance condition was defined as changing the lamp in the museum and the equal illuminance condition corresponds to not only changing the lamp, but also keeping the illuminance equal.
(4) From this experiment,we found that the discoloration of dyed fabrics showed a closer relationship to the exposure dose of illuminance (lx•hr)than that of irradiance (W•hr).

KEYWORDS:fluorescent lamp, dyed fabrics, discoloration reduction effect, equal irradiance, equal illuminance

Characteristics of Illuminance and Shadow on the Working Plane under Task Ambient Lighting — With Varied Task Light Positions —
Akira UCHIDA and Yoshihiko OHTANI

 In Task Ambient Lighting, the characteristics of illuminance and shadow on the working plane become complex, because Task Light is often set up in various locations. Therefore, data concerning these characteristics is needed,when the lighting design that considers the shadow is done. In this paper, the characteristics of illuminance and shadow on the working plane were evaluated under changing Task Ambient Lighting conditions,created by changing the position of the Task Light. As a result, at a position for the Task Light where the value of the uniformity ratio of illuminance becomes the maximum,it is clear that minimum illuminance and average illuminance have a higher value,and the maximum shadow factor and rate of shadow area have a lower value.

KEYWORDS:Task Ambient Lighting, Monte Carlo method, illuminance calculation, shadow

Developing Mechanism of Emission in Xenon Discharge Lamps with Inner and Outer Electrodes
Hidehiko NOGUCHI, Hidetoshi YANO, Hideki MOTOMURA, Masafumi JINNO and Masaharu AONO

 We investigated a developing mechanism of emission in a xenon discharge lamp with inner and outer electrodes using a high-speed electronic camera.At a low operating frequency, a negative glow appears on the inner surface of the glass tube during the positive half cycle while the inner electrode operates as an anode,and a diffused positive column appears in the discharge space during the negative half cycle while the inner electrode works as a cathode.At a high operating frequency, a contracted positive column appears in the center of discharge space near the inner electrode during the positive half cycle and the negative half cycle. VUV radiation intensity and phosphor emission intensity in the diffused positive column are three-times greater than those in the contracted positive column.

KEYWORDS:xenon discharge lamp, mercury free lamp, diffused positive column, contracted positive column

Validity of Environmental Brightness Estimation by Virtual Luminance Distribution Method
Yasuo OGIUCHI and Taiichiro ISHIDA

 Our recent studies have shown that the main factor for determining of envionmental brightness is the perceived amount of light filling a space.Therefore,to estimate the environmental brightness from the physical properties of a space,we have to compute the physical quantity that corresponds to the perceived amount of light filling the space.We propose using the virtual luminance distribution methods (VLDM) to estimate environmental brightness. Because our past results did not show that VLDM is more effective than other environmental brightness indices, we performed a new experiment. In the experiment, the subjects evaluate enviromntal brightness of the inside of test boxes with variant reflectance of the walls and variant lighting patterns by using the magnitude estimation method.The brightness estimated using VLDM correlated well with that evaluated by the subjects. However, the vertical illuminance at the point of the subjects.eyes correlated poorly the estimated brightness. This demonstrates that VLDM is valid for brightness estimation.We performed another experiment in order to investigate the difference between using VLDM and the reference matching method (RMM) for brightness evaluation.The results show that it is possible to estimate the brightness evaluation using RMM by considering photometry and brightness unlinearity.This suggests there is a similarity between the psychological process of brightness evaluation using RMM and the computation process of brightness estimation using VLDM.

KEYWORDS:brightness of a space, perception of lighting environment, virtual luminance distribution method, reference matching method

A Novel Investigation on Assessment of Solar Radiation Using Silicon-based Pyranometer
Junsetsu TAMURA, Kenji OTANI and Kosuke KUROKAWA

 It is important to assess the energy of photovoltaic systems,expected to be installed widely in the future.A method for estimating the amount of solar radiation incident in photovoltaic systems is needed. We propose a method to correct the differences between the observed values of thermopile-based pyranometers and silicon-photodiode-based pyranometers and the examined values, for all weather conditions, that uses a Clearness Index and a Moving-Average model.We show that the observed value of silicon-photodiode-based pyranometers is corrected to the observed value of thermopile-based pyranometers.

KEYWORDS:photovoltaic system, solar radiation, thermopile-based pyranometer, silicon-based pyranometer, clearness index, moving average

Study on Germicidal Effects of Water by Germicidal Lamp
Yasuhiko YAMANAKA, Masaaki MORITA, Kimitoshi HORAGUCHI, Takao YAMAYOSHI and Wataru SUGIURA

 The effects of germicidal radiation on water has shown many good properties, and the method is applied to several purposes including and purifying drinking water, pure disinfecting water. In this paper we discuss the theoretical and practical results of germicidal effects on both of using a cylindrical germicidal tank with a germicidal lamp in the center on still and flowing water. We are describe the water transmission properties that we developed for the germicidal radiation. The four tables below show the results of our experiments.
Table 1 Index of natural water and permeation rate(τ)
Table 2 The properties of dissolving material in cooling tower water
Table 3 Germicidal time for E-coli
Table 4 Experimental results of twin-type circulation water disinfection

KEYWORDS:application of ultraviolet radiation,germicidal lamp,germicidal radiation,water disinfection,transmittance of water for ultraviolet radiation

Evaluation on Color Rendering Effect of Landscape Lighting
Yoshio NAKASHIMA and Mamoru TAKAMATSU

KEYWORDS:color rendering effect, light-up, semantic differential technique, image-estimation, factor analysis

Fabrication of CdS Two-dimensional Photonic Crystals Using rf Sputtering and Assessment of Their Emission Properties
Osamu HANAIZUMI, Takehiro KOGA and Yuzo HASEGAWA

KEYWORDS:photonic crystal, CdS, rf sputtering, photoluminescence, enhancement of emission, photonic bandgap