نتایج جستجو برای: forest harvesting operations for extracting of forest products in these trails

تعداد نتایج: 25583941  

پایان نامه :0 1375

to explore the idea the investingation proposed, aimed at finding whether the performances of the population of iranians students studying english in an efl context are consistent in l1 and l2 writing taks and whether there is a cross-linguistic transfer in this respect. in this regard the subjects were instructed to write four compositions-two in english and two in farsi-which consisted of an ...

Journal: :جنگل و فرآورده های چوب 0
آزاده دلجویی کارشناس ارشد مهندسی جنگل دانشکدة منابع طبیعی دانشگاه تهران، کرج، ایران احسان عبدی دانشیار گروه جنگلداری و اقتصاد جنگل دانشکدة منابع طبیعی دانشگاه تهران، کرج، ایران باریس مجنونیان استاد گروه جنگلداری و اقتصاد جنگل دانشکدة منابع طبیعی دانشگاه تهران، کرج، ایران

forest roads are directions in natural habitats that used to transport wood products, secondary forest products and recreation. constructing forest roads causes trees clearing with specified width thus lead to direct or indirect changes in forest ecosystems and forest environment. this study aims to assess the changes of diversity and richness indices in main and secondary forest roads in a par...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه اصفهان 1389

implicit and unobserved errors and vulnerabilities issues usually arise in cryptographic protocols and especially in authentication protocols. this may enable an attacker to make serious damages to the desired system, such as having the access to or changing secret documents, interfering in bank transactions, having access to users’ accounts, or may be having the control all over the syste...

2000
D. Athanassiadis G. Lidestav

When subjecting forest products to certification the total environmental load of wood harvesting machinery should also be assessed. In this study fuel, hydraulic oil and lubricant consumption in harvesting operations in Sweden has been examined by using machine data acquired through a questionnaire. The objectives of the study were to assess the contractor and forest company owned harvesters’ a...

پایان نامه :دانشگاه آزاد اسلامی واحد کرمانشاه - پژوهشکده زبان و گویش 1393

abstract the purpose of this study is twofold: on the one hand, it is intended to see what kind of noticing-the –gap activity (teacher generated vs. learner generated) is more efficient in teaching l2 grammar in classroom language learning. on the other hand, it is an attempt to determine which approach of the noticing-the-gap- activity is more effective in the long- term retention of grammar...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه صنعتی اصفهان 1390

we commence by using from a new norm on l1(g) the -algebra of all integrable functions on locally compact group g, to make the c-algebra c(g). consequently, we find its dual b(g), which is a banach algebra so-called fourier-stieltjes algebra, in the set of all continuous functions on g. we consider most of important basic theorems about this algebra. this consideration leads to a rather com...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان تهران - دانشکده زیست شناسی 1388

126 abstract: in this research we studied the effects of cyclic hydration and dehydration of cysts of artemia urmiana and artemia parthenogenetica on the hatching percentage, survival and growth. the experiment was carried out in 3 treatments (1-3 hydration/dehydration cycles) with 3 replicates for each treatment. later effects of cold preservation at -20°c during three time periods were ...

Journal: :caspian journal of environmental sciences 2008
r. naghdi a. bonyad

this research was conducted in the west forest of guilan, northern iran. data from various harvesting methods for 20 years were collected. results showed that, productivity rate of round wood, pulp wood and fuel wood has had an upward trend, while rate of traditional products (lumber, sawn wood, charcoal, etc.) has had a downward trend. production cost has been investigated in this research. th...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز - دانشکده علوم 1391

in this research we have studied the effect of some transition-metals (cu, ag and au) substitutions on two-electron reduction potential of flavins by application of dft method. all geometries have been optimized at blyp level of theory and “6-31+g** + lanl2dz” mixed basis set. the frequency job at the same method and basis sets has been performed to obtain gibbs free energy of compounds. it h...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تحصیلات تکمیلی علوم پایه زنجان - دانشکده ریاضی 1393

in this thesis, a structured hierarchical methodology based on petri nets is used to introduce a task model for a soccer goalkeeper robot. in real or robot soccer, goalkeeper is an important element which has a key role and challenging features in the game. goalkeeper aims at defending goal from scoring goals by opponent team, actually to prevent the goal from the opponent player’s attacks. thi...

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