The aim of this project is to investigate the photocatalytic activity ZnO/TiO2 composite films for gas-phase oxidation ethanol. Pure TiO2, pure ZnO, and their composites were formulated using a sol-gel synthesis method, resulting powders cast dried as thin in flat-plate ultraviolet light-emitting diode (UV LED) reactor. P25 TiO2 commercially available ZnO also used comparison. structural, morph...

Two types of photoreceptors are found in the median ocellus of Limulus. One type is maximally sensitive to ultraviolet (UV) light, the other to green light; they are called UV and VIS cells, respectively. Biphasic receptor potentials, consisting of a small initial hyperpolarizing phase and a later slow depolarizing phase, can be recorded from both receptor types. These biphasic responses are el...

The present study is the first report of utilizing TiO2 photocatalyst to analytically calibrate the hydroperoxyl radical (HO2). An in-situ calibration method of HO2 is proposed for air monitoring by using an 2-methyl-6-(pmethoxyphenyl)-3,7-dihydroimidazo-[1,2-a]pyrazin-3-one (MCLA)-chemiluminescence (CL) technique. In this method, HO2 (pKa = 4.80) is produced by the ultraviolet (UV) photolysis ...

Conventional validation testing of UV reactors use cultured microorganisms spiked into test water flowing through a reactor. These tests are limited by the microbe titer it is possible to grow, thus limiting the size of the reactor it is possible to validate. The goal of this study was to examine the UV inactivation of indigenous aerobic spores naturally occurring in raw/unfiltered water suppli...

Abatement of trichloroethylene (TCE, 250 ppm in air) was studied in a novel nonthermal plasma (NTP) dielectric barrier discharge reactor with an inner electrode made of sintered metal fibers (SMF). The SMF electrodes modified with TiO2 and MnO2 were observed to be catalytically active. Their efficiency in TCE decomposition was compared with a Cu inner electrode. The SMF electrode modified with ...

As part of a project to validate a UV reactor for disinfection of drinking water, the germicidal output of four medium pressure lamps housed in a continuously operating reactor was followed as a function of time. Spectra were measured monthly and were used in conjunction with radiometer readings to calculate germicidal fluence rates (using DNA absorbance weighting) at the radiometer sensor posi...

basil plants (ocimum basilicum l.) were sprayed with salicylic acid (1mm) and exposed to ultraviolet-c (uv-c) radiation (40 wm-2) after emergence of six developed leaves. plants were grown for 18 days and exposed to uv-c for 5 mind-1 alternatively. chlorophyll a, chlorophyll b and carotenoide were considered for analysis of photosynthetic pigments. the results showed that the photosynthetic pig...

Liquid foods might present interferences in their optical properties that can reduce the effectiveness of short-wave ultraviolet radiation (UV-C) treatments used for sterilization purposes. The effect turbidity as UV-C interference factor against inactivation bacterial spores was analysed by using phosphate-buffered saline solutions (PBS) different values (2000, 2500, and 3000 NTU) which were a...

Background & objectives: Because of its very high solubility, nitrate penetrates easily into soil and underground waters. Surface waters such as lakes, reservoirs, and rivers are exposed to nitrate pollution. Photocatalytic processes have a high potential for nitrate removal due to complete oxidation, lack of formation of multi-cycle metabolites and the availability of catalysts. The purpose of...

There are many benefi ts that are brought by sun, such as positive feeling and mood and trigger the production of vitamin D in skin. But giving to the skin an overdose of ultraviolet rays (UV) may be harmful to our bodies and result in premature skin ageing, skin cancers, eye damage and photoimmunosuppression. UV radiation is made up of three types of rays with different wavelength (λ): ultravi...