نتایج جستجو برای: wood model

تعداد نتایج: 2139723  

Journal: :علوم دامی ایران 0
الناز بابایی کارشناس ارشد گروه علوم دامی دانشکدۀ کشاورزی دانشگاه ارومیه رسول پیرمحمدی دانشیار گروه علوم دامی دانشکدۀ کشاورزی دانشگاه ارومیه

to evaluate the nutritive value in some lignocellulosic materials, 3 sets of experiments were conducted on aspen, and grape woods. to enhance the digestibility, the woods were treated with 5% naoh. throughout the first trial, chemical composition and digestibility coefficients of dry matter, organic matter and ndf of experimental feeds, ph of rumen, as well as palatability were evaluated while ...

2009
Dana R. Warren Clifford E. Kraft William S. Keeton Jared S. Nunery Gene E. Likens

Wood is an important component of forested stream ecosystems, and stream restoration efforts often incorporate large wood. In most cases, however, stream restoration projects are implemented without information regarding the amount of wood that historically occurred or the natural rates of wood recruitment. This study uses a space-for-time analysis to quantify large wood loading to 28 streams i...

2004
Falk K. Wittel Gerhard Dill-Langer

The anisotropy of wood within the radial-tangential (RT) growth plane has a major influence on the cracking behavior perpendicular to grain. Within the scope of this work, a two-dimensional discrete element model is developed, consisting of beam elements for the representation of the micro structure of wood. Molecular dynamics simulation is used to follow the time evolution of the model system ...

2009
William Gacitúa Michael Wolcott

The main objective of the research presented here was to relate anatomical features of wood species that affect the interactions between polymeric phases and performance of wood plastic composites (WPC). These interactions were related to the probable interlocking volume and surface area for stress transfer in a WPC. Composites were produced from different wood species and analyzed using SEM (s...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علامه طباطبایی 1390

over the past decades a number of approaches have been applied for forecasting mortality. in 1992, a new method for long-run forecast of the level and age pattern of mortality was published by lee and carter. this method was welcomed by many authors so it was extended through a wider class of generalized, parametric and nonlinear model. this model represents one of the most influential recent d...

2010
Arijit Sinha Rakesh Gupta John A. Nairn

Wood and wood-based composites are being used extensively in single-family residential dwellings. Therefore, it is important to categorize their response when exposed to elevated temperatures for a sustained period of time. In fireresistant design for wood structures, the main goal is to ensure that enough structural integrity is maintained, during and after a fire, to prevent collapse and to m...

2000
Guangjie Zhao Jinzhen Cao

In order to clarify the molecular mechanism of the reorientation of adsorbed water in wood cell wall during dielectric relaxation process, the temperature and frequency spectrums of the dielectric relaxation process based on adsorbed water in wood, acetylated wood and formaldehyde-treated wood were measured, respectively, within a range of -60-20°C, 30Hz-3MHz and 0-27%m.c. On this basis, the qu...

Journal: :Environmental science & technology 2006
Bernine I Khan Jenna Jambeck Helena M Solo-Gabriele Timothy G Townsend Yong Cai

Wood treated with chromated copper arsenate (CCA) is primarily disposed within construction and demolition (C&D) debris landfills, with wood monofills and municipal solid waste (MSW) landfills as alternative disposal options. This study evaluated the extent and speciation of arsenic leaching from landfills containing CCA-treated wood. In control lysimeters where untreated wood was used, dimethy...

Journal: :Journal of theoretical biology 2011
Catherine Coutand Jean-Denis Mathias Georges Jeronimidis Jean-François Destrebecq

Trees are able to maintain or modify the orientation of their axes (trunks or branches) by tropic movements. For axes in which elongation is achieved but cambial growth active, the tropic movements are due to the production of a particular wood, called reaction wood which is prestressed within the growing tree. Several models have been developed to simulate the gravitropic response of axes in t...

2013
Timothy D. Perkins

MODEL OVERVIEW AND BACKGROUND INFORMATION The tapping zone of a maple tree is defined as the area around the circumference of the stem that can be utilized for sap collection. For sap collection with tubing, it can be thought of as a radial band of wood based at the point on a tree where the dropline meets the lateral tubing of the sap collection system. The physical boundaries of the tapping z...

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