By adopting a sedentary way of life, the Neolithic groups increased their awareness of territoriality. During the 9600-6900 BCE period in the Near East, there were also innovations in arrowheads, yet no important changes in the animals hunted was detected.
3. Poor screen preparation is a major cause of pinholes. Particles of dirt, wood frame chips, and dust remaining on the fabric during coating will be trapped in the emulsion. Opaque, they will block light from hardening the emulsion beneath them, so that the emulsion in these small areas will wash away after exposure.
Condensers, including those made of copper, steel or aluminum also develop leaks from acid eating through from the inside and winter road salt and/or salt water along the coasts causing deterioration from the outside. Acid will cause small pinhole leaks to develop in the condenser coil and the evaporator coil. Flaked off debris and sludge will flow to the bottom tubes of the condenser causing both restrictions and a concentrated accumulation of acid to eat at the coil. Sludge and debris at the bottom of the evaporator coil will not normally cause a restriction but will eventually cause reduced cooling efficiency.