Influence of temperature on the modulus of elasticity (MOE) of Pinus sylvestris L.

Holzforschung ◽  
2004 ◽  
Vol 58 (2) ◽  
pp. 143-147 ◽  
Author(s):  
P. Dias de Moraes ◽  
Y. Rogaume ◽  
P. Triboulot

Abstract The influence of temperature on the modulus of elasticity (MOE) and on the flexural stiffness of Pinus sylvestris L. was determined under temperature conditions ranging from 25 to 300°C for samples with a water content of about 6.0%. The experiments were carried out on microsamples, with a thermomechanical analyser, in isothermal conditions and under temperature ramping rates. The behaviour of the curves of the MOE is explained by wood drying and by the behaviour of the wood polymers as a function of temperature. The results obtained by thermomechanical analysis were validated by the results obtained by centre-point bending tests on small scale samples, which therefore allows for its use in modelling the behaviour of timber structures during a fire.

2012 ◽  
Vol 26 (3) ◽  
pp. 259-269 ◽  
Author(s):  
M. Kočárek ◽  
R. Kodešová

Influence of temperature on soil water content measured by ECH2O-TE sensorsThe aim of this study was to investigate the influence of temperature on water content value measured by ECH2O-TE sensors. The influence of temperature on measured soil water content values was clearly demonstrated. Soil water content values measured during the day apparently oscillated with oscillating soil temperatures. Average daily temperature and soil water content were calculated for selected periods. Regression relationships between deviations of soil temperature and soil water content from their daily average values were evaluated. Correlation between the soil water content and temperature deviations increase with the soil depth due to the lower influence of rainfall and evaporation at the soil surface on measured soil water content values in deeper soil layersegsoil water content oscillation was controlled mostly by oscillating temperature. The guideline values of linear regression equations (R2>0.8) were very similar, close to value 0.002 and the intercept values were equal to zero. The equation for recalculation of measured soil water content values at given temperature to reference soil water content for reference soil temperature, was propozed on the basis of this analysis.


Author(s):  
Analha Dyalla Feitosa Lins ◽  
Francilania Batista da Silva ◽  
Jarderlany Sousa Nunes ◽  
Ana Paula Trindade Rocha ◽  
Gilmar Trindade de Araújo

<p>O repolho é uma hortaliça folhosa com grande valor nutritivo e poder antioxidante, porém rapidamente deteriora-se pelo elevado teor de água. O processo de desidratação de polpa ou purê de frutas e hortaliças tem sido amplamente empregado, devido a preservação das qualidades nutricionais e por sua vez, a secagem em leito de jorro vem sendo amplamente utilizada por atender principalmente esse requisito. Embora os resultados relativos à qualidade dos pós, indiquem a viabilidade do leito de jorro, faz-se necessários estudar qual a influência da temperatura nas características físico-químicas do pó obtido. Tendo em vista todos os argumentos mostrados, o presente trabalho tem como objetivo estudar a influência da temperatura do leito de jorro nas características físico-químicas do repolho roxo. Primeiramente foi obtido o sumo e a caracterização físico-químico do mesmo, em seguida o mesmo foi desidratado em leito de jorro nas temperaturas de 60, 70 e 80 °C e posteriormente os pós obtidos foram submetidos a avaliação físico-química: atividade de água, teor de água, pH, acidez total titulável, teor de sólidos solúveis (°Brix) e cor. Os valores de atividade de água e acidez diminuíram com o aumento da temperatura ocorrendo o inverso para os outros parâmetros. Sendo verificada uma influência significativa da temperatura sob os parâmetros físico-químicos.</p><p align="center"><strong><em>Influence of drying temperature in spouted bed under the physicochemical characteristics of red cabbage</em></strong><strong><em></em></strong></p><pre><strong>Abstract:</strong> Cabbage is a leafy vegetable with high nutritional value and antioxidant power, but quickly deteriorates because of the high water content. The pulp or mashed fruits and vegetables dehydration process has been widely used due to preservation of nutritional quality, and in turn, the drying in spouted bed has been widely used to cater mainly this requirement. Although the results on the quality of post indicate the feasibility of the spouted bed, it is necessary to study the influence of temperature on the physicochemical characteristics of the resulting powder. In view of all arguments shown, the present work aims to study the influence of the spouted bed temperature on the physicochemical characteristics of the purple cabbage. First was obtained juice and physicochemical characterization of it, then it was dried in spouted bed at temperatures of 60, 70 and 80 ° C and then the powders were subjected to physicochemical evaluation: water activity , water content, pH, titratable acidity, soluble solids (° Brix) and color. The water activity and acidity values decreased with increasing temperature, the opposite occur for the other parameters. It is verified a significant influence of temperature on the physical and chemical parameters.</pre>


Author(s):  
T. Geipel ◽  
W. Mader ◽  
P. Pirouz

Temperature affects both elastic and inelastic scattering of electrons in a crystal. The Debye-Waller factor, B, describes the influence of temperature on the elastic scattering of electrons, whereas the imaginary part of the (complex) atomic form factor, fc = fr + ifi, describes the influence of temperature on the inelastic scattering of electrons (i.e. absorption). In HRTEM simulations, two possible ways to include absorption are: (i) an approximate method in which absorption is described by a phenomenological constant, μ, i.e. fi; - μfr, with the real part of the atomic form factor, fr, obtained from Hartree-Fock calculations, (ii) a more accurate method in which the absorptive components, fi of the atomic form factor are explicitly calculated. In this contribution, the inclusion of both the Debye-Waller factor and absorption on HRTEM images of a (Oll)-oriented GaAs crystal are presented (using the EMS software.Fig. 1 shows the the amplitudes and phases of the dominant 111 beams as a function of the specimen thickness, t, for the cases when μ = 0 (i.e. no absorption, solid line) and μ = 0.1 (with absorption, dashed line).


2010 ◽  
Vol 25 (1) ◽  
pp. 93-105 ◽  
Author(s):  
Daniel Żarski ◽  
Dariusz Kucharczyk ◽  
Wojciech Sasinowski ◽  
Katarzyna Targońska ◽  
Andrzej Mamcarz

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