peppermint (mentha piperita l.) from lamiaceae family is one of the most important medicinal plants, used in food, sanitary and cosmetic industries. a field experiment was carried out in ferdowsi university of mashhad in 2010-2011 to evaluate the effects of three irrigation levels (100, 80 and 60 percent of water requirements calculated by evaporation pan class a) and two mulch types (black pla...

      Dust storms are increasingly threatening the forest ecosystem in Western Iran. Due to its coverage of vast area of Zagros forest, the Quercus brantii is at the front line of the attack. Most tree deaths in this forest are from this species. This study aims to investigate the effect of simulated dust on wood development and leaf stomata from seedlings of Persian oak. The oak seedlings were...

With an evolving political environment of commitments to limit emissions of greenhouse gases, and of markets to trade in emissions permits, there is growing scientific, political, and economic need to accurately evaluate carbon (C) stocks and flows—especially those related to human activities. One component of the global carbon cycle that has been contentious is the stock of carbon that is phys...

Investigation on structure and dynamics of natural forest ecosystems is an important issue for silvicultural decisions. The aim of this study is to analysis dynamics and structure of a beech stand during 5-year period in the Shast Kalateh forest in the Caspian region, North of Iran. Data were collected from a 16.9ha permanent research plot established in a natural unlogged stand in 2006. All li...

Polygalacturonase production under different shear stress environments by Aspergillus sp. was studied. It was found that the rate of enzyme production in the stirred tank fermentor decreased with increasing the stirrer speed in the range 300-750 rpm. On the other hand, in a split cylinder air-lift fermentor, the rate of polygalacturonase production slightly increased with increasing in air ...

in this study, the physical properties (size, mass, volume, density, geometric diameter, sphericity and friction coefficient on galvanized steel and wood surface) and some mechanical properties of flesh and skin tissue (modulus of elasticity, bioyield stress, yield strain and toughness) for small, medium and large melons of ghasri variety were determined. means comparison was done by duncan’s m...

Sweetgum (Liquidambar styraciflua L.) wood blocks were decayed by Postia (= Poria) placenta in soilblock cultures. Decay was terminated at various weight losses, and the pore volumes available to four low molecular weight molecules, (water, 4 Å,; glucose, 8 Å,; maltose, 10 Å; and raffinose, 128,) and three dextrans (Mr 6,000, 38 Å; 11,200, 51 Å; and 17,500, 61 Å) were determined by the solute e...