The utilization of natural raw materials has been practiced for centuries. Of materials, wood and its bark have outstanding significance because their special chemical components unusual structure. Annual production is estimated to be between 300 400 million m3. different tree species used extensively in or conjunction with modern technologies. This article presents a comprehensive summary these methods results. diversity derives from the variety possibilities encoded material. Following...

The aim of this paper is to carry out a rheological study the pressing pine wood sawdust, after which obtaining briquettes from same material with hydraulic installation and analyzing their properties. In order know behavior during pressing, fractions resulting sorting sawdust 4 × 4, 3 3, 2 2, 1 mm2 sieves were used, respectively, six (the fraction larger than smaller one are added) specific device, placed on universal testing machine. results obtained in showed that density does not...

Because of the uneven colour black locust wood, different technologies are used to change colour, bestknown being chemical and thermal treatments. Some them affect mechanical properties such as elasticity modulus, strength, durability. This study aims compare physical wood control samples treated with ammonia hydroxide, in terms density profile, values (CIE L*, a*, b*), subjected static bending, viscous-elastic (storage modulus (E'), loss (E") damping (tan)).Two types ammonia-fuming...

Abstract Modeling dynamic heterogeneity in amorphous shape memory polymers (SMPs) is a huge challenge due to the complex statistics of strain energy distributions during their thermodynamic relaxations. In this study, based on distribution, we have considered, for first time, influences different temperature rates and evolution as equilibria, rather than quasi-static problem. We propose phase transition model incorporated with Gaussian distribution investigate equilibria glass tailorable...

A dynamic trap well model is developed to describe the complex relaxations of functional segments, and explore working principles behind hydrothermal coupling effect in shape memory polymers (SMPs). constitutive relationship among fixity strain, recovery strain relaxation time has been formulated characterize using geometrical parameters (i.e. width height) wells. Moreover, effects temperature solvent absorption on behaviours SMPs have based Flory-Huggins theory Fokker-Plank probability...

Abstract Coexistence of multiple and discrete segments as well their distinctive hysteresis relaxations enables amorphous shape memory polymers (SMPs) exhibiting complex disordered dynamics, which is critical for the glass transition behavior to determine effect (SME), but remained largely unexplored. In this study, a dynamic model proposed explore working principle collective dynamics in SMPs, towards connection between relaxation behavior, can be applied design realization SMEs SMPs....

Abstract Semi-crystalline polymers offer great opportunities for design and tuning of multi-shape memory effect (multi-SME) through their programmable melting transitions. However, coexistence amorphous crystalline components as well multiple interfaces results in complex cooperative dynamics. In this study, we propose a one-dimensional multi-modal dynamic model to describe the commutative dynamics semi-crystalline shape undergoing multi-SME. A three-phase Takayanagi principle are firstly...

The problem of industrial use tree bark is relevant and has practical importance for complex processing wood raw material. Barks are available in Hungary Russia large quantities, but they not widely used different purposes than producing energy. One the perspective areas utilization its as material production thermal insulation panels. present study focuses on capacity bark. Thermal conductivity properties two broadleaved (black locust (Robinia pseudoacacia), pannónia poplar (Populus...

Abstract Highly entangled gels have gained extensive attention due to their excitingly large deformation and high toughness. To understand the toughening mechanism of these highly gels, an entanglement constraint model has been established, based on spatially prismatic Gaussian distribution models. A free-energy function is formulated study conformational dynamics, rubbery elasticity sliding effect topological knots in chains. Monte Carlo, molecular dynamics finite element analysis were...

An energetic model of a typical log home was placed in ten different regions Russia and examined the yearly heating energy demand. The building supplied with three types windows to demonstrate effect on In 108 m2 building, changing 3.5 W/m2K thermal insulation capacity 1.4 0.7 caused an saving 11.9% 15.9% respectively. heated space reducing night temperature by 2 degrees Celsius can result only 2.7% (1 865 kWh) colder Magadan region, while Mediterranean Krasnodar, there 4.48% 151 net amount....

Wood is a natural smart material which possesses shape memory effect (SME). The paper deals with SME behaviour of sound and mycologically destroyed wood shows the influence cellulose, hemicelluloses, lignin content on ability to remember temporary recover permanent shapes. research was carried out sliced veneer samples (beech Fagus sylvatica L. pine Pinus sylvestris L.) rotten (pocket rot, brown rot) reveal deformative conversions quantities SME. Results are shown that at moisture drop...

The strength and strains of the wood-cement composite primarily depend on main technоlogical factors such as used type binder wood filler, method filler preparation, molding, conditions hardening. aim this work is an experimental study chemical additives influence to localize harmful effects water-soluble substances processes hydration hardening cement. Using additives, it possible achieve satisfactory parameters even green wood. maximum was obtained when complex were applied. most effective...

The change of the specific wood surface at shape memory effect is considered in this paper. study was conducted using sorptive analyzer and distribution pores according to size Quadrasorb SI. Specific samples SSA, сm2/g, found by low-temperature adsorption krypton liquid nitrogen temperature (77K) cal-culated Brunauer-Emmett-Teller (BET) method. beech, pine, oak sliced veneer birch rotary-cut were investigated.

Термическая модификация древесины в последние десятилетия является одним из наиболее динамично развивающихся направлений научных исследований области деревообработки

Protracted stay in space affect human organism several negative ways. The foremost factors of influence are radiation and zero gravity. However exploration is a necessary historical prospective the problem significantly mitigating effects cosmic on very important today. paper describes series experimental data indicating unique ability plants for self-regeneration. Among those abilities record-breaking resistance, shape memory effect, generation rising electric potentials under strain pulses...