The Luminescence Of Black Light :: essays research papers

The Luminescence of Black Light Black Light. What is it? It is a portion of the Ultra-Violet Spectrum that is invisible to our eyes. We can not distinguish it. However, when this radiation impinges on certain materials visible light is emitted and this is known as "fluorescence." Fluorescence is visible to the human eye, in that it makes an object appear to "glow in the dark." There are several sources of ultra-violet light. These sources are: the sun, carbon arcs, mercury arcs, and black lights. In most cases, the production of ultra-violet light creates a reasonable amount of heat. Many materials exhibit the peculiar characteristic of giving off light or radiant energy when ultra-violet light is allowed to fall upon them. This is called luminescence. In most cases, the wave length of the light radiated is longer than that of the ultra-violet excitation but a few exceptions have been found. The quantum theory attempts to explain this property by contending that a certain outside excitation causes an electron to jump from one orbit to another. It is then in an unstable environment causing it to fall back into its original orbit. This process releases energy, and if it is in the visible part of the spectrum, we have a transient light phenomenon. Ultra-violet light is an exciting agent which causes luminescence to occur. There are many materials which exhibit fluorescent characteristics. Many of which are even organic. Teeth, eyes, some portions of the skin, and even blood exhibit fluorescent qualities. Naturally occurring minerals such as: agate, calcite, chalcedony, curtisite, fluorite, gypsum, hackmanite, halite, opal scheelite, and willemite, also have similar characteristics. These materials can be used in industries. The radiance of ultraviolet light is measured in units called "Angstrom." The intensity of ultraviolet fluorescence is the greatest between the 5000 and 6000 range. This being the range between the green and yellow hues. Ultra violet light is not readily visible. It is not visible because certain materials reflect it. Ultra-violet light is made visible due to the fact that it causes a reaction at the atomic level. When it strikes the atom, some of the electrons are sent into other orbits.

Educating the Exceptional Learner Essay

The reading week provided many new ideas and one of those was the gifted and talented, creative. Learning about children and youth with these extraordinary abilities of; elaboration, transformation and visualization. Sternberg, states in the reading that, â€Å"Individuals can be talented and may display extraordinary skills in mathematics, sports, music, or other performance areas. † I have worked with students that display these extraordinary abilities and many are also gifted with a high intelligence quotient. But, many also have no social abilities. They have no idea how to make friends or how to talk to their peers. They struggle with social interactions and boundaries. There are some exceptions and it is always a pleasant surprise to experience these exceptions. In another part of the reading, they talked about the mental age of a student. This phrase was new for me. A student’s mental age is based on their intellectual abilities. In the reading, J. P. Guilford saw intelligence as â€Å"a diverse range of intellectual and creative abilities†. This concept is very powerful because of its views on intelligence as much broader. There are many who have contributed to the definitions of giftedness. The definitions and concepts of giftedness appears to have an explanation that serves a purpose of influence; what the student is qualified for, the amount of funding and training for educators. â€Å"This is not the universally accepted definition of giftedness? † (Clark, 2008). Characteristics of giftedness are limited and are an inadequate sample of various ethnic and cultural groups, so the studies do not represent this group as a whole. Giftedness can come from many diverse sectors. The origin of giftedness has a lot of controversy. Geneticists determined that giftedness is heredity and can have environmental influences, but environmentalists allege otherwise. Plomin and Price (2003) captured it best when they said â€Å"it may well be more appropriate to think about general cognitive ability as an appetite, rather than the aptitude. It appears assessments like testing done today are being used with children for whom they were designed and children, who were once excluded, are now being included. I feel when children are included good things are bound to happen. How to use this information in the classroom is to provide students with the right type of testing. The correct testing will help discover the students’ abilities, abilities that would no rmally not be evident in everyday classroom performances.

American Apparel Swot Anaysis Essay - 3402 Words

American Apparel SWOT Analysis Marketing 304 Section 12382 Group# 5 Nancy Alonzo Yavon Irving Salvador Bustos Cory Lashinsky American Apparel is a vertically integrated clothing manufacturer, wholesaler, and retailer. AAI is best known for making basic, solid color T-shirts and undergarments. They have expanded into dresses, denim, bedding, pants, and accessories for men, women, children, babies, and dogs. Their long-term goal it to become the #1 destination for basic apparel – the first name that consumers think of for t-shirts, sweatpants, underwear, socks, etc. What sets American Apparel apart from other clothing companies is that every aspect of their production takes place in the center of Los Angeles, California,†¦show more content†¦Fruit of the Loom, Hanes, and Gildans’ weaknesses include not actively cooperating with WRC (workers’ rights consortium) investigations, and giving incorrect severance pay to laid off workers. Other weaknesses include the employment of sweatshop workers and the exportation of employment opportunities to other countries. As a vertically integrated company, they manufacture, wholesale, and retail their own clothing line. They independently own and operate over 280 retail stores in 20 countries. American Apparel sells directly to its customers through their AmericanApparel.net website. The site has an online inventory of over 250,000 items and receives 1.5 million visitors per month. Online sales grew from $13.3 million in 2006 to roughly 40 million in 2009. The company’s site also runs on the Yahoo Stores platform and is included in the Internet Retailer 500 index. They also sell through an eBay store. They sell wholesale under the American Heavy label. American Apparel is one of the largest wholesalers in the country. American Apparel shirts are used as band merchandise and concert t-shirts for the bands, among many others. It was reported in 2007, that their retail distribution channel accounted for 55% of sales; wholesale for 39%; and online for 6%. Some of the retail stores are underperforming and may require closing. American