to detection of suitable sampling method to study tree canopy cover in the northern zagros forest, baneeh region forest, kurdistan province, and west of iran was selected. 40 square sample plots one hectare (100×100 m) were selected and perfect inventoried. in every sample plot the position of tree, kind of species and two diameter of crown (m) were recorded. to study of canopy cover different ...

the study of spatial and temporal changes in climate parameters, is one the most important issues in the world's climate research. study of changes in cloud cover as one of the most important climate parameters is important, because clouds are in top of hydrologic cycle and changes in them make changes in spatial and temporal variations in other climate parameters. in this study, the spati...

pragmatic assessment and consistency in rating are among the subject matters which are still in need of more profound investigations. the importance of the issue is highlighted when remembering that inconsistency in ratings would surely damage the test fairness issue in assessment and lead to much diversity in ratings. our principal concern in this study was observing the criteria that american...

This research aimed to determine the effects of different cover crops and application ofbio-fertilizer on dynamic of nitrogen in the soil and sweet maize yield. Also, we evaluated theeffect of fall–winter species (common vetch, field pea, winter oats, fodder kale) and a mixtureof vetch and field pea with oats used as cover crops, as such as dead organic mulch andtraditional variant, without cov...

Soil and water resources management of rivers has an important role because of direct relation withdifferent systems such as earth, life, social and people. Although the use of vegetation cover inbioengineering and biological stabilization and also soil and water resources management projects hasmany advantages, but improper methods of design and implementation cause hydraulic specificationsof ...

T HROUGH an amendment to the Railroad Unemployment Insurance Act, approved by President Truman on July 31,1946, the Railroad Retirement Board was charged with the responsibility of establishing and administering a sickness insurance program for railroad employees.’ Thus, sickness benefits now form an integral part of the railroad retirement and unemployment insurance systems. The programs for p...

objective: citrus (citrus reticulata) is one of the most important horticultural plant in iran and weed management throuth ecological methods such as cover crop is a proper option in orchard management practices. methods: the experiment was designed as a split plot on the base of complete randomized block design with four replications in mazandaran province, sari, voushka county from 2010 to 20...

We consider various hitting and piercing problems for the family of axis-parallel rectangles induced by a point set. Selection Lemmas on induced objects are classical results in discrete geometry that have been well studied and have applications in many geometric problems like weak epsilon nets and slimming Delaunay triangulations. Selection Lemma type results typically bound the maximum number...