نتایج جستجو برای: water absorption and swelling

تعداد نتایج: 16952760  

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...

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

one of the most commonly used techniques to reduce the corrosion rate of rebar in concrete is addition substances named corrosion inhibitors into the concrete. corrosion inhibitor is chemical compounds that were added to concrete to prevent corrosion of steel in concrete. sodium nitrate is a type of anodic inhibitors that this study investigatesthe effect of this inhibitor on the properties of ...

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

in this research, water and steam absorption behavior and also effect of maleic anhydride polypropylene (mapp) on these behaviors in wood fiber-polypropylene composite were compared. for this purpose, the composites were manufactured from 60% fibers and 40% polypropylene in presence and absence of ma. the oven dried samples with dimensions of 2.5×2.5×1 cm were immersed in distilled water and ex...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه خلیج فارس - دانشکده مهندسی 1393

in civil engineering concrete is a material combined of hydraulic cement, sand, gravel and water. gravel and sand compose 60 to 70 percent of concrete. these aggregates support compression force of concrete. cement paste acts as glue to stick grain together. in bushehr factories producing aggregates do not operate according to astm standards, so that fineness modulus (fm) of the produced sands ...

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: :مهندسی سازه 0
ایمان عشایری شهاب الدین یثربی

expansive behavior is usually observed in soils, which contain fractions of clay minerals in their composition. water absorption of clay particles and change of natural water content of soil up to plastic limit and down to shrinkage limit will cause significant volume change in expansive soils and will result in severe damages to the structures, buildings and foundations. swelling potential is ...

Journal: :caspian journal of environmental sciences 2007
p. rezayati charani j. mohammadi rovshandeh? b. mohebby o. ramezani

hydrothermal treatment of wood material products with many interesting properties such as enhanced dimensional stability, lower equilibrium moisture content and increased biological durability. the effects of hydrothermal treatment on dimensional stability, oven dry density and water absorption of beech wood (fagus orientalis) naturally grown, has been studied in present research that extremely...

B. Mohebby J. Mohammadi Rovshandeh? O. Ramezani P. Rezayati Charani,

Hydrothermal treatment of wood material products with many interesting properties such as enhanced dimensional stability, lower equilibrium moisture content and increased biological durability. The effects of hydrothermal treatment on dimensional stability, oven dry density and water absorption of beech wood (Fagus Orientalis) naturally grown, has been studied in present research that extremely...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - پژوهشکده مهندسی فرایند 1395

abstract: mineral scaling in oil and gas production equipment is one of the most important problem that occurs while water injection and it has been recognized to be a major operational problem. the incompatibility between injected and formation waters may result in inorganic scale precipitation in the equipment and reservoir and then reduction of oil production rate and water injection rate. ...

Journal: :international journal of nano dimension 0
a. haghighi poshtiri wood and paper sciences and technology dept., faculty of natural resources, university of tehran, iran. h. r. taghiyari wood science & technology dept., the faculty of civil engineering, shahid rajaee teacher training university, iran. a. naghi karimi institute of tropical forestry & forest products (introp), university putra malaysia (upm) & dept. of wood science & technology, faculty of natural resources, the university of tehran, iran.

fire-retarding properties of wollastonite nanofibers in poplar wood (populus nigra) were studied here. some physical properties such as water absorption, volumetric swelling and anti-swelling efficiency (ase) were also measured. specimens were prepared according to the iso 11925 specifications for the fire-retarding properties and according to the astm d4446 -2002 specifications for the physica...

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