in this study, the effects of oleothermal modification on physical and mechanical peroperties of fir wood (abeis sp.) blocks were examined. at first, some blocks of fir wood with 5 × 20 × 120 cm dimensions were prepared. the blocks were treated in soybean oil. the effects of 3 factors such as treatments temperature (180and 200 °c), holding time (12 and 15 h) and initial moisture content of wood...

One of the most important types of water erosion, is massive erosion. Soils with fine particles (especially silt particles) have little stability against erosion, because they have more water holding capacity and thus increase the saturation moisture and the likelihood of this type of erosion. So In this study, to investigate the relationship between particle size of silt, with behavior and rhe...

The aim of this study was to investigate the relationship between physical and chemical properties of soils with vegetation distribution in Divan-Darre rangeland as one of the most important rangelands in Kurdistan province. For this purpose, a random systematic 150 m × 200 m gird sampling plan was used to establish 90 sampling plots. In each plot, soil factors and percent cover of each plant s...

this study attempts to investigate the effect of peers’ revision in comparison to that of the teacher, and whether peers’ comments and teachers’ comments facilitate students’ revision? if yes, which one is more effective? also attempts have been made to see which aspects of language are more highlighted by peers versus teachers when commenting. besides, it is investigating the student’s attitud...

.  Introduction Old trees are important and key elements of forest sites and are of great value in terms of forest management, reforestation, silviculture and ecology. Although old trees constitute a small percentage of forest trees, they account for a large share of forest carbon reserve and play a vital role in carbon storage. Understanding the how geographical and site distribution of thes...

Many factors including climate, type of rootstock, soil properties, geological factors, plant nutrition and irrigation affect the quantity and quality of orange fruit. In this study, the relations between citrus orchards conditions, their soil properties and leaf elements concentration and fruit quality were evaluated. The experiment was conducted as a randomized complete block design and soil,...

  Studying soil phosphorus fractions is useful in understanding soil pedogenesis as well as soil fertility. In this reseach, 20 soil samples were taken from different depths of 0-30 and 30-60 cm of upper-slope, mid-slope and lower-slope positions of four toposequences in arid (Jei and Ziar in Isfahan) and semiarid (Farokhshahr and Shahrekord) regions. In each toposequence, the soil depth was re...

in order to examine the ecological conditions and characteristics of fraxinus excelsior l. in the northern forests of iran 6 main areas as well as some miscellaneous ones , have been selected in the region respectively in : lomir2, shafaroud , park - e-noor , ahlam , alandan and noor.