T HE livability of stored bull spermatozoa is decreased by aerobic agitation (Prince and Almquist, 1948). Hydrogen peroxide has been implicated in defects of motility, livability and metabolism in spermatozoa of various species (MacLeod, 1943; VanDemark et al., 1949; Tosic and Walton, 1950; Wales et al., 1959). Investigations not involving spermatozoa have demonstrated that exogenous hydrogen p...

sustainability creates solutions that solve the economic, social and environmental challenges. it has been studied and managed over many scales of time and space and in many contexts. the paper reviews the definitions of sustainability respecting the ecologic concept as well the need for balanced sustainability within its three pillars on equal way, then it goes throw ecologic architecture with...

Contemporary cities face many challenges, none the least from an urban planning perspective. Global climate change is putting pressures on planning for combatting and adapting to a warmer climate, increased levels of rainfall, etc. Urbanization urges planners to satisfy an increased need for housing in an already dense environment, without compromising the livability of neighborhoods. The overa...

The use of the metabolism concept, expanded to include aspects of livability, is applied to cities to demonstrate the practical meaning of sustainability. Its application in industrial ecology, urban ecology, urban demonstration projects, business plans and city comparisons are used to illustrate its potential. # 1999 Elsevier Science B.V. All rights reserved.

Livability is one of the key characteristics that urban architects strive to achieve. It even more important for commercial streets, where functional diversity and constant movement people require special consideration. In capital city Erbil, Iraq, streets suffer from neglect. However, there huge potential create an attractive environment purposes other than shopping. Some countries have develo...