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

تعداد نتایج: 25583941  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شهید چمران اهواز - دانشکده علوم 1370

1- in a search directed to the reaction of compound)23(the cycloaddition reaction of 1,3- diphenylisobenzofurane)14(with p-benzoquinone)19(,followed by addition of cyclopentadiene was carried out.the specific spacial stracture of its ir,nmr,mass spectra. 2- in another attempt the kinetic stability and behavior of compounds)20(and)23(was studied.the main subject of this study was the highly reve...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علامه طباطبایی 1388

a major concern in the last few years has been the fact that the cultural centers are keeping distance with what they have been established for and instead of reproducing the hegemony, they have turned into a place for resistance and reproduction of resistance against hegemony. because the cultural centers, as urban public spaces in the last two decades, have been the subject of ideological dis...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سمنان - دانشکده مدیریت و اقتصاد 1392

these days, all department stores make an effort to provide their clients with valuable products in order to project the best image for them. as a result, clients’ comprehension risk will decrease and they will be more willing to repurchase. having a good image is really important for the department stores because it makes an impression on clients’ comprehension of both quality and risk. consid...

R. Mousavi Mirkala

Damage to residual stand is unavoidable and it is one of the main important issues in the forest harvesting. Trees damage may occur in felling and skidding work phase or during skid trail construction. In any case, damage can be very serious to residual stand. Detailed study is necessary to find out the amount and severity of damage to trees; therefore district 14 of Kilesara in Guilan Province...

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

nanotechnology is a general term which is related with field of all advanced science term that generally predicates with all modern technologies which consider nanoscales. improvement in the quality of products by adding some nanoparticles and study of their behavior in the presence of these nanoparticles have been obtained in many researches. on the other hand numerous demands for sowing ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شهید چمران اهواز - دانشکده ادبیات و علوم انسانی 1390

abstract: advertisements are the most accessible type of authentic materials, and this is one reason why they are used more and more in english teaching classes. for this cause, studies in the field of advertisements are very widespread nowadays. for pun is one aspect which makes advertisements more interesting, it is used more than before in advertisements. use of puns makes an advertisement m...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه صنعتی اصفهان - دانشکده منابع طبیعی 1392

nowadays, air pollution is a global problem that has had significant growth by technology development, population growth andindustrial development. industrial development brought natural resources deterioration, more manufacturing products, and more environmental pollutants. if pollutant won’t be controlled, human-being and wildlife will face the critical risks. significant release and critical...

Journal: :محیط زیست طبیعی 0
مقداد جورغلامی استادیار گروه جنگلداری، دانشکده منابع طبیعی، دانشگاه تهران، ایران باریس مجنونیان استاد گروه جنگلداری، دانشکده منابع طبیعی، دانشگاه تهران، ایران

hyrcanian (caspian) forest in northern iran with many endemic and endangered species is a rich area for biodiversity. the use of ground-based skidding is well accepted practice for the extraction of timber from the forest, but this has tended to cause the greatest environmental problems. the aim of the study was to evaluate and comparison of environmental impacts, residual stand damage, regener...

Forest utilization is one of the important components of get income and decrease of poverty for local communities. Zagros as the widest forests area in country, in terms of commercial non-wood forest products are unique. The amount of income from these forest products varies, and in each region a specific type of product is the important source of income. The purpose of this study was to determ...

Journal: :محیط زیست طبیعی 0
مقداد جورغلامی استادیار گروه جنگلداری، دانشکده منابع طبیعی، دانشگاه تهران، ایران

in forest harvesting, there is an ongoing trend to increase constantly the size, power and load of logging machines. this may cause soil degradation in forest ecosystems as the passes of these machines modify important soil structural characteristics. the present study was conducted to examine impact of skidding traffic, trail slope, traffic frequency, and soil depth on bulk density and soil co...

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