نتایج جستجو برای: holding time and press temperature on wood density

تعداد نتایج: 18751621  

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

in this study, the effects of oleothermal modification on physical and mechanical peroperties of fir wood (abeis sp.) blocks were examined. at first, some blocks of fir wood with 5 × 20 × 120 cm dimensions were prepared. the blocks were treated in soybean oil. the effects of 3 factors such as treatments temperature (180and 200 °c), holding time (12 and 15 h) and initial moisture content of wood...

Journal: :جنگل و فرآورده های چوب 0
پیمان فلاح مقدم-بهمبری دانش آموختۀ کارشناسی ارشد علوم و صنایع چوب و کاغذ, دانشگاه تربیت مدرس، نور، ایران بهبود محبی دانشیار، گروه علوم چوب و کاغذ دانشگاه تربیت مدرس، نور، ایران حوری شریف نیا دیزبنی دانشجوی دکتری فراورده های چندسازۀ چوب، دانشگاه تربیت مدرس، نور، ایران

in this research work, it was planned to study influences of hydrothermal treatment temperature, holding time and press temperature on wood density, spring back, moisture absorption as well as dimensional stability of combined-hydro-thermo-mechanically modified poplar wood. wood blocks were treated hydrothermally at temperatures 120, 150 and 180°c for holding time of 0, 30 and 90 min. afterward...

Journal: :پژوهش های علوم و فناوری چوب و جنگل 0

paulownia is one of the fast-growing species that was attended to supply industrial requirement in recent years. the application of this species is limited because of low density, so wood modification via compression and densification is an effective method. for this purpose, the paulownia boles were prepared from shastkalateh forest and cut into blocks with 60×20×20 mm dimension. the variable ...

پایان نامه :دانشگاه تربیت معلم - تهران - دانشکده علوم 1393

in this thesis, structural, electronical, and optical properties of inverse pervskite(ca3pbo) in cubic phase have been investigated.the calculation have been done based on density functional theory and according to generalized gradiant approximate (gga) as correlating potential. in order to calculate the configurations, implementing in the wien2k code have been used from 2013 version. first of ...

Journal: :جنگل و فرآورده های چوب 0
محمد رضا عبده کارشناس ارشد علوم و صنایع چوب و کاغذ، گروه علوم و صنایع چوب و کاغذ، دانشکدة منابع طبیعی و علوم دریایی، دانشگاه تربیت مدرس، نور، ایران امیر موتاب ساعی کارشناس ارشد علوم و صنایع چوب و کاغذ، گروه علوم و صنایع چوب و کاغذ، دانشکدة منابع طبیعی و علوم دریایی، دانشگاه تربیت مدرس، نور، ایران بهبود محبی دانشیار گروه علوم و صنایع چوب و کاغذ، دانشکدة منابع طبیعی و علوم دریایی، دانشگاه تربیت مدرس، نور، ایران سعید کاظمی نجفی استاد گروه علوم و صنایع چوب و کاغذ، دانشکدة منابع طبیعی و علوم دریایی، دانشگاه تربیت مدرس، نور، ایران

influences of temperature as well as holding time on physical and mechanical properties of fir wood were studied in this work during the oleothermal wood modification. wood samples were cut and treated oleothermally in the soybean oil at 200 and 230°c for the holding time of 1, 3 and 5 hours. weights and the dimensions were measured before and after treatment. bending strengths, water absorptio...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شهید چمران اهواز - دانشکده مهندسی علوم آب 1393

drought is transient phenomenon , slow , repetitive and integral part of the climate of each region. drought begins with a substantial reduction in precipitation over the long-term average rainfall and over time, reduced soil moisture and surface and ground water resources will continue to decrease. this phenomenon is the most important in bakhtegan basin because of its importance in strategic ...

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

in this work, a novel and fast method for direct analysis of volatile compounds (davc) of medicinal plants has been developed by holding a filament from different parts of a plant in the gc injection port. the extraction and analysis of volatile components of a small amount of plant were carried out in one-step without any sample preparation. after optimization of temperature, extraction time a...

Journal: :int. j. lignocellulosic products 2014
a. kargarfard a. jahan-latibari

the target of this study was to investigate the possibility of mdf productionfrom eucalyptus camaldulensis wood. mdf fibers were produced applying threelevels of steaming time. laboratory mdf boards were produced using thegenerated fibers and different pressing temperature and time. physical andmechanical properties of mdf panels were measured using relevant eu testmethods and were statisticall...

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

run-out-table (rot) is located between last finishing stand and down coiler in a hot strip mill. as the hot steel strip passes from rot, water jets impact on it from top and bottom and strip temperature decreases approximately from 800-950 °c to 500-750°c. the temperature history that strip experience while passing through rot affects significantly the metallurgical and mechanical properties, s...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه فردوسی مشهد - دانشکده ادبیات و علوم انسانی دکتر علی شریعتی 1392

the present paper investigates how far ideologies can be tease out in discourse by examining the employed schemata by two ideologically opposed news media, the bbc and press tv, to report syria crisis during a period of nine months in 2011. by assuming that news is not a valuefree construction of facts and drawing on micro structural approach of schema theory, for the first time in discours...

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