Ultraviolet light-emitting diodes (UV-LEDs) have started replacing UV lamps. The power per LED of high-power LED products has reached 12 W (14 A), which is 100 times the values observed ten years ago. In addition, the cost of these high-power LEDs has been decreasing. In this study, we attempt to understand the technologies and potential of UV-LEDs.

In this study, influence of nano-zinc oxide treatment on the UV protection properties widely used apparel fabrics including flax, polyester, and nylon, were investigated by means ultraviolet factor (UPF) assessment. Nanoparticle content nylon determined to be 1.2, 0.9, 1.5 wt%, respectively. The UPFs non-treated in range 2.2 entire region. An improvement UPF was obtained after introducing nanop...

We have found that coupling between catharanthine and vindoline occurs non-enzymatically in the presence of flavin mononucleotide and manganese ions with near-ultraviolet light irradiation in vitro. The present study found that the concentrations of catharanthine and vindoline in Catharanthus roseus decreased and those of dimeric indole alkaloids increased under near-ultraviolet light at 4 degr...

Sol-gel technique was used to coat multiwall carbon nanotubes (MWCNTs) with anatase titania to increasing the surface area and improve the photocatalytic activity of TiO2. Room temperature ballistic conduct of MWCNT combined with semiconducting behavior of anatase brought about a photocatalytic improvement of ~37 % with respect to the highest methyl orange decolorization flair. For characteriza...

Titanium dioxide (TiO2) is a well-known photocatalyst for environmental cleaning and energy conversion. However, it can only be excited by ultraviolet light for photocatalysis due to its wide band gap (3.2 eV). In this paper, we present a novel (Yb,Er)-NaYF4/C-TiO2 composite which can be perfectly induced not only by ultraviolet light but also weak visible and near infrared lights, owing to the...

The gram-negative bacteria Brucella melitensis was investigated to evaluate its susceptibility to UVC radiation at 254 nm. At an intensity of 18.7 mW/cm2 of UVC, the time required for inactivation of B. melitensis was 240 seconds in both dark and light, whereas it was 120 seconds and 240 seconds in dark and light respectively at an intensity of 19.5 mW/cm2. The results indicate that vaccinal st...

The effect of ultraviolet irradiation on fluorinated graphene (FG) dispersed in toluene was investigated for the first time. The chemical and physical characteristics of FG before and after ultraviolet irradiation were analyzed by UV-vis, FTIR, XPS,EDS, oxygen flask combustion (OFC), XRD, TGA, Raman, SEM, TEM and fluorescence spectroscopy. It is found that the F/C ratio initially decreases rapi...

The high quality LCLS electron beam generated in the photoinjector is subject to many instabilities in the downstream acceleration and compression. The instability can be initiated by any density modulation of the electron beam generated at the photocathode. In this paper, we prescribe the tolerance on the initial electron beam density modulation possibly introduced by the ultraviolet (uv) lase...

We use ultraviolet spectra of Capella from the Hubble Space Telescope (HST) and Far Ultraviolet Spectroscopic Explorer (FUSE) satellites to study interstellar absorption lines from the Local Interstellar Cloud (LIC). Measurements of these lines are used to empirically determine the ionization states of carbon, nitrogen, and silicon in the LIC, for comparison with the predictions of theoretical ...