نتایج جستجو برای: species variations of root tensile strength in beech

تعداد نتایج: 24469047  

Journal: :محیط زیست طبیعی 0
احسان عبدی استادیار گروه جنگلداری و اقتصاد جنگل، دانشکده منابع طبیعی، دانشگاه تهران، ایران باریس مجنونیان استاد گروه جنگلداری و اقتصاد جنگل، دانشکده منابع طبیعی، دانشگاه تهران حسن رحیمی استاد گروه آبیاری، دانشکده مهندسی آب و خاک، دانشگاه تهران محمود زبیری استاد گروه جنگلداری و اقتصاد جنگل، دانشکده منابع طبیعی، دانشگاه تهران قاسم حبیبی بی بالانی دانشیار دانشگاه آزاد اسلامی واحد شبستر

effects of plant roots on increasing soil shear strength depend on root tensile strength. thus, determination of root tensile strength can provide the necessary data for analyzing root-soil relations. tensile strength of plant roots varied in a wide range and have been reported from thousands to millions of mpa. the main objective of this study was to assess inter-species variations of root ten...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده منابع طبیعی و علوم دریایی 1388

this research was conducted in two protect and destroy region in the middle zagros, in illam province. in order to identification of ecological species group and evaluate density of regeneration, effect of many factors such as protection, vegetation, physiographic factors, physical and chemical properties of soil in study locations were studied. to achieve these purpose number of 54 plots using...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز 1381

‏‎the community dynamics of aquatic coleoptera(insecta)in one of the spring-stream habitats of bammo national park in fars province called cheshmeh-ye-ghanbari is studied as a pilot project and model for acquaintance with and furthering the biodiversity studies on fauna of iran. sixteen species-populations out of nineteen of this community were already identified for their taxonomy and for thei...

پایان نامه :0 1371

the treatment of in completely formed pulpless teeth has presented considrable problems. these teeth have wide open apexes and the walls of the root canal diverge toward the apical tissues. mechanical preparation cannot be done in the normal manner beacause of the large initial size and the taper of apical part of the canal , a mechanical stop cannot be produced at the apex of the canal and , t...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1388

based on the latest records of typhlops vermicularis merrem, 1820 from iran, this species is distributed in the northern and southern regions of the country. in this study, new records of typhlops vermicularis are presented and it is shown that distribution range of this species is extended towards the eastern and western iran, and according to the new distribution map, it can be assumed that t...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان 1390

cement is an essential ingredient in the concrete buildings. for production of cement considerable amount of fossil fuel and electrical energy is consumed. on the other hand for generating one tone of portland cement, nearly one ton of carbon dioxide is released. it shows that 7 percent of the total released carbon dioxide in the world relates to the cement industry. considering ecological issu...

پایان نامه :دانشگاه تربیت معلم - تهران - دانشکده ادبیات و علوم انسانی 1392

this study tried to explore disciplinary variations of web blurbs across soft and hard knowledge fields on the one hand, and to illustrate how academic publishers exploit interactional metadiscourse devices in move structure of their blurbs on the other.

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تحصیلات تکمیلی علوم پایه زنجان - دانشکده شیمی 1391

in this thesis a calibration transfer method is used to achieve bilinearity for augmented first order kinetic data. first, the proposed method is investigated using simulated data and next the concept is applied to experimental data. the experimental data consists of spectroscopic monitoring of the first order degradation reaction of carbaryl. this component is used for control of pests in frui...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه فردوسی مشهد - دانشکده علوم 1376

saluk mount is selected for devonian biostratigraphy. this area located at southwest of bojnurd. in this study three sections are selected and two sections, chahar-borj and tabar sections with a thickness of 650 m, which consist mainly of calcareous sediments was studied in detailed but third section, qelli section, with a thickness of about 450m which consist mainly of sandstone and evaporates...

2016
Yuanjun Yang Lihua Chen Ning Li Qiufen Zhang

The stabilization of slopes by vegetation has been a topical issue for many years. Root mechanical characteristics significantly influence soil reinforcement; therefore it is necessary to research into the indicators of root tensile properties. In this study, we explored the influence of root moisture content on tensile resistance and strength with different root diameters and for different tre...

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