Wyniki wyszukiwania - Biblioteka Nauki

1

The influence of strain amplitude, temperature and frequency on complex shear moduli of polymer materials under kinematic harmonic loading

100%

Hashemi M. , Zhuk Y.

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2017

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tom Vol. 21, nr 1

157--170

EN

Modeling of the cyclic deformation of viscoelastic materials as the key aspects of analysis of the structural behavior is performed. The approach that uses the complex-value amplitude relations is preferred rather than direct numerical integration of the complete set of constitutive equation for the material. Time dependent transient inelastic response of polymer materials to monoharmonic kinematic loading is simulated by the Goldberg constitutive model. To predict the steady-state response in terms of amplitudes, the relations between the amplitudes of main field variables are established with making use of complex moduli concept. It is performed by making use of equivalent linearization technique. It is shown that this technique leads to overestimation of stress amplitude. To avoid this, the modified equivalent linearization technique is applied. Characterization of the complex moduli dependence on frequency and temperature as well as amplitude of strain intensity is performed. Results demonstrate a weak dependence of loss moduli on the frequency of the loading within the wide interval of it, while variation of storage moduli with increasing temperature is more pronounced.

2

Determination of volatile organochalcogens using liquid phase microextraction and gas chromatography with fluorine-induced chemiluminescence detection

80%

Hashemi M. , Montes R. A. , Chasteen T. G.

Environmental Biotechnology

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2012

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tom Vol. 8, No. 2

55--62

EN

In this study, a simple and rapid liquid phase microextraction technique coupled with gas chromatography and fluorineinduced chemiluminescence detection has been developed for determination of volatile organochalcogens (dimethyl sulfide, dimethyl disulfide, dimethyl trisulfide and dimethyl diselenide and dimethyl telluride). The effects of extraction parameters such as extracting solvent and its volume, stirring time extraction time and salt effect were optimized. Also, analytical figures of merit such as response linearity, repeatability and reproducibility, and limits of detection have been evaluated. The proposed method was found to be a simple and rapid analytical procedure for determination of volatile organochalcogens in real aqueous samples with detection limits of 5-620ng·l-1. The relative recoveries of these analytes for spiked bacterial cultures, tap water and lake water ranged from 95 to 105% with the relative standard deviations of 0.3-11.0%.

3

Morpho-physiological and phytochemical traits of (Thymus daenensis Celak.) in response to deficit irrigation and chitosan application

70%

Bistgani Z. E. , Siadat S. A. , Bakhshandeh A. , Pirbalouti A. G. , Hashemi M.

Acta Physiologiae Plantarum

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2017

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tom 39

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nr 10

4

The effect of methyl jasmonate on enzyme activities in wheat genotypes infected by the crown and root rot pathogen Fusarium culmorum

70%

Motallebi P. , Niknam V. , Ebrahimzadeh H. , Enferadi S. T. , Hashemi M.

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nr 11

EN

The hemibiotrophic pathogen Fusarium culmorum (Fc) causes crown and root rot (CRR) in wheat. In this study, MeJA treatment was done 6 h after pathogen inoculation (hai) to focus the physiological and biochemical responses in root tissue of the susceptible wheat cv Falat, partially resistant cv Pishtaz and the tolerant cv Sumai3 at the beginning of the necrotrophic stage. The results indicate that treatment with MeJA at 6 hai significantly delayed the necrotic progress in cv Falat, whereas no significant difference was seen in other cultivars. The activities of pathogen responsive defense-related enzymes (SOD, CAT, POX, PPO, LOX and PAL), total phenols and callose contents were higher in Sumai3, while treatment with MeJA significantly increased these enzymes activities and total phenols content in Falat, signifying the most sensitive cultivar which had a weak reaction to the pathogen but a strong response to MeJA treatment. Additionally, MeJA treatment decreased the level of H2O2 and MDA contents particularly in cv Falat. This is the first work reporting the regulation of defense-related enzymes by MeJA treatment at particular time point of 6 hai suggests the possible role of JA in regulating basal resistance in CRR pathogen–wheat interaction. Taken together, our data add new insights into the mechanism of wheat defense including enzymatic events controlling wheat protection against Fc infection.

5

Validation of pedigree relationships using a multiplex microsatellite marker assay in iranian holstein cattle

61%

Hashemi M. , Amirinia C. , Harkinezhad M. T. , Banabazi M. H. , Javanmard A. , Amiri F.

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2013

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tom 13

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nr 3