Tags » Ultraviolet Light

Hunting the Spirits

First, let me preface this with my own beliefs concerning supernatural matters here on earth. I am a Bible Believing Christian. I believe that human souls do not continue to inhabit the earth after death. 1,397 more words

Do your sun protection clothes really protect you with sunblock?

Everybody knows that the ultraviolet sunlight will cause the skin cancer and that’s the main reason we choose sun protection clothes when we are doing the outdoor activities. 406 more words

Hubble Ultra-Deep Field

The 2014 edition of the Hubble Ultra-Deep Field, a composite image of separate exposures taken from 2003 to 2012 with the Hubble Space Telescope… 38 more words



We fair-haired or fair-skinned folks have learned to be cautious in our dealings with outdoor activities.  The Sun is both our friend and our foe.  We learned, sometimes the physically painful way, to protect ourselves from solar radiation. 530 more words


HVAC Coils — Keeping Them Clean

Keeping condensing and cooling coils clean increases their efficiency by 15%-30% depending on what research paper you read. The problem with most of these coils is they are difficult to get at or inside the AHU and require shutting the system down — which may not be a viable option. 745 more words

HVAC Articles

Heliogravure III - Ultraviolet Light with Digital Screen

Updated 26/01/2016

Hardening the gelatin. In heliogravure, it is necessary an illumination source rich in ultraviolet (UV) light. This UV light must provoke the cross link reaction into the gelatin previously sensitized with potassium bichromate (K2Cr2O7). 1,467 more words

Early Photography