In the context of the art, architecture, and culture of Ancient Greece, the Classical period, sometimes called the Hellenic period, corresponds to most of the 5th and 4th centuries BC (the most common dates being the fall of the last Athenian tyrant in 510 BC to the death of Alexander the Great in 323 BC).his Classical period saw the annexation of much of modern-day Greece by the Persian Empire, its subsequent independence, and it also had a powerful influence on the Roman Empire and greatly influenced the foundations of western civilization.
Photography gels are precisely colored acetate sheets (overhead transparencies) used to alter the color of lights.There are different reasons for doing this, including for aesthetic effects and contrast reasons.hanks again-I had flash on floor behind me with red gel, flash on keyboard bounced off white paper on screen, and third flash with a home made snoot pointing to Apple logo-I made three A4 pages and got 27 gels for $4.50 Cdn.
A gel (coined by 19th-century Scottish chemist Thomas Graham, by clipping from gelatine) is a solid, jelly-like material that can have properties ranging from soft and weak to hard and tough. Gels are defined as a substantially dilute cross-linked system, which exhibits no flow when in the steady-state.ydrogels are highly absorbent (they can contain over 90% water) natural or synthetic polymeric networks. Hydrogels also possess a degree of flexibility very similar to natural tissue, due to their significant water content. The first appearance of the term 'hydrogel' in the literature was in 1894.