نتایج جستجو برای: except for fiber width and lumen width

تعداد نتایج: 19069587  

Journal: :جنگل و فرآورده های چوب 0
امیر سعادتی دانشجوی کارشناسی ارشد بیولوژی و آناتومی، گروه علوم و صنایع چوب و کاغذ، دانشکدۀ منابع طبیعی، دانشگاه تهران، کرج، ایران کامبیز پورطهماسی دانشیار گروه علوم و صنایع چوب و کاغذ، دانشکدۀ منابع طبیعی، دانشگاه تهران، کرج، ایران سید علیرضا سلامی استادیار گروه علوم باغبانی و مهندسی فضای سبز، دانشکدۀ علوم و مهندسی کشاورزی، دانشگاه تهران، کرج، ایران رضا اولادی استادیار گروه علوم و صنایع چوب و کاغذ، دانشکدۀ منابع طبیعی، دانشگاه تهران، کرج، ایران

natural, renewable, biodegradable and low pollution hemp fibers are an alternative to trees xylem and artificial fibers. in this study, xylem and bast fiber properties of six iranian hemp populations including length, width, wall thickness, lumen width and wall index were measured and compared. to this purpose, collected population seeds from different parts of iran were nursed in a controlled ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده فنی 1391

the study of air infiltration into the buildings is important from several perspectives that may be noted to energy and design of hvac systems, indoor air quality and thermal comfort and design of smoke control systems. given the importance of this issue, an experimental and numerical study of air infiltration through conventional doors and windows has been explored in iran. to this end, at fir...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان - دانشکده مهندسی 1392

flow in natural river bends is a complex and turbulent phenomenon which affects the scour and sedimentations and causes an irregular bed topography on the bed. for the reason, the flow hydralics and the parameters which affect the flow to be studied and understand. in this study the effect of bed and wall roughness using the software fluent discussed in a sharp 90-degree flume bend with 40.3cm ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان - دانشکده مهندسی عمران 1391

in this study, scour of mashkid bridge pier located in mashkid river of saravan county has been studied and to measure the scour rate, the numerical model hec-ras 4.0 has been used. upon selection of mashkid river as the case study and whereas the studied zone is important with respect to the climatic conditions and showery monsoon raining and flowing the great and destructive floodwaters, ther...

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

abstract: country’s fiber optic network, as one of the most important communication infrastructures, is of high importance; therefore, ensuring security of the network and its data is essential. no remarkable research has been done on assessing security of the country’s fiber optic network. besides, according to an official statistics released by ertebatat zirsakht company, unwanted disconnec...

2015
Hui Zhan Guo-jian Tang Chang-ming Wang Shu-guang Wang

The chemical properties and fiber morphology of Fargesia fungosa at different culm ages and height portions were investigated. The variations in moisture, ash, SiO2, and toluene–alcohol extractive contents with culm ages were greater than they were with heights. The holocellulose varied neither significantly with age nor with height. The fiber length, width, length-to-width ratio, and wall thic...

2007
R. Moya Roque

A short rotation system was possible in the Gmelina arborea plantations due to silvicultural techniques that increased their growth rate. The objective of this research was to determine growth rate effects measured in tree diameter on wood density parameters (mean, minimum, maximum and intra-ring variation) and in fiber dimensions (wall thickness, fiber width, lumen diameter and fiber length) o...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه بیرجند - دانشکده کشاورزی 1390

abstract this study is carried out to determine the chemical composition in the three vegetative stages of the haloxylon sp., degradation parameters, with adding naoh and ca(oh2 ). for this purpose, in may and october and january 2010 enough some haloxylon sp. of the ammary area was prepared. crude protein and ash percentage are decrease, neutral detergent fiber percentage with pragress stage ...

Journal: :iranian endodontic journal 0
aliakbar rezaei department of prosthodontics, dental school, shahid beheshti university of medical sciences, tehran, iran fereidoon soltani department of prosthodontics, dental school, shahid beheshti university of medical sciences, tehran, iran fariborz vafaei department of prosthodontics, dental school, hamadan university of medical sciences, hamadan, iran masoumeh khoshhal department of periodontics, dental school, hamadan university of medical sciences, hamadan, iran. majid reza ayatollahi department of mechanical engineering, iran university of science and technology, tehran, iran. naser soltani department of mechanical engineering, tehran university of medical sciences, tehran, iran.

introduction: many studies have been performed to evaluate the stress distribution around endodontic posts; those which compared posts composed of different materials are rare. the aim of this study was to compare stresses induced in dentin by three structurally different posts using photoelasticity method. materials and methods: nine blocks of psm-5 photoelastic material with 45×45×10 mm dimen...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان - دانشکده مهندسی عمران 1392

abstract in aggregate, active forms of reactive silica with mineral names are sometimes associated with sand and gravel in concrete mixture. alkali hydroxides originated from alkalis in the cement or other resources form an alkaline silica gel with this reactive silica which becomes swallowed and expanded during time causing damage to concrete. there have been growing researches on alkaline r...

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