نتایج جستجو برای: wood fibers

تعداد نتایج: 109254  

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

influences of the wood fiber acetylation as well as the compatibilizer mapp on water absorption, thickness swelling and dimensional stability of acetylated wood/ polypropylene composites (wpcs) were the main concerns of this research. wood fibers were acetylated with acetic anhydride without using any catalyst to achieve weight percent gains (wpgs) of 4.5, 7.5 and 17.6%. the acetylated fibers w...

Journal: :علوم و تکنولوژی پلیمر 0
اسماعیل قاسمی حامد عزیزی پروین احسانی نمین

the growing interest in using natural fibers as reinforcing agents of polymer-based composites is mainly due to their advantages such as lower cost, lower density, ease of preparation, lower energy requirements for processing, biodegradability, wide availability and relative non-abrasiveness over traditional reinforcing fibers such as glass and carbon. in this study, wood-plastic composite (wpc...

1998
Y. Deng Yulin Deng

The Wilhelmy principle was used to investigate the wettability of wood fibers in various aqueous solutions. The sensitivity and reproducibility of the measurement were significantly improved by using a group of separated fibers as compared to a single-fiber method that was reported previously. This accurate and reproducible method allowed us to investigate contact angle and wettability of wood ...

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

in this research, the effect of tension wood formation in populus nigra on its anatomical characteristics was studied. vessel element and ray frequency (n/mm²), vessel diameter and ray dimensions were measured in both normal and tension wood. furthermore, the formation of gelatinous layer (g-layer) in the fibers of tension wood was studied. the results showed that the vessel proportion and diam...

Journal: :هنرهای نمایش و موسیقی 0
امیرسهیل پیرایش فر کارشناس پلیمر، دانشکده فنی مهندسی، دانشگاه آزاد اسلامی واحد علوم و تحقیقات محمدمهدی جلیلی استادیار دانشکده فنی مهندسی، دانشگاه آزاد اسلامی واحد علوم و تحقیقات سید یحیی موسوی کارشناس پلیمر، دانشکده فنی مهندسی، دانشگاه آزاد اسلامی واحد علوم و تحقیقات

in this study, the disadvantages of wood, which is widely employed in producing music instruments, are discussed. for example, high moisture sensitivity, low impact resistance, and time-consuming procedure as well as various properties of different species or in several parts of one specimen which are the main problems of wooden music instruments are extensively discussed in this paper. many ma...

2007
Umesh Prasad Agarwal

This chapter reviews applications of Raman spectroscopy in the field of wood and pulp fibers. Most of the literature examined was published between 1998 and 2006. In addi­ tion to introduction, this chapter contains sections on wood and components, mechanical pulp, chemical pulp, modified/treated wood, cellulose I crystallinity of wood fibers, and the “self-absorption” phenomenon in near-infrar...

2016
Yue Zhang Wenbo Zhang Wei Lu

Wood-based carbon fiber derived from liquefied wood has the disadvantages of low mechanical strength and unstable performance. To improve its mechanical properties, wood-based carbon fiber precursors were impregnated with 5 wt.% and 8 wt.% boric acid solutions for 1 h and then carbonized at 900 °C for 1 h. The effect of boron content on fiber tensile strength and microstructure was investigated...

2013
Rubaiyat Sharmin Sultana Mahabubur Rahman

Due to a non-vertical orientation of the stem or branch, which may begin as responses of prevailing winds, snow, slope, or asymmetric crown shape, a specialized wood tissue forms, is called “reaction wood”. In hardwood species, the reaction wood tends to form on the upper side of a leaning stem or branch, is known to as “tension wood”. It is usually related with eccentric growth and changes in ...

Journal: :Fungal biology 2018
Andrew L Loyd Benjamin W Held Eric R Linder Jason A Smith Robert A Blanchette

The laccate (shiny or varnished) Ganoderma contain fungi that are important wood decay fungi of living trees and decomposers of woody debris. They are also an important group of fungi for their degradative enzymes and bioprocessing potential. Laboratory decay microcosms (LDMs) were used to study the relative decay ability of G anoderma curtisii, Ganoderma meredithiae, Ganoderma sessile, and G a...

Journal: :علوم و تکنولوژی پلیمر 0
علی اکبر عنایتی امید حسینایی سی چوان وانگ سیداحمد میرشکرایی مهدی تجویدی

hemicellulose of southern yellow pine wood spices was extracted by pressurized hot water at three different temperatures: 140°c, 155°c and 170°c. compounding with pp (polypropylene) was performed by extrusion after preparing wood flour and sieving to determine its mesh size. the ratio of wood to polymer was 50:50 based on oven-dry weight of wood flour. all extraction treatments and control samp...

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