Tag Archives: warming

xxx L. Argentel-Martínez, J. Garatuza-Payán, T. Arredondo, E.A. Yépez
Effects of experimental warming on peroxidase, nitrate reductase and glutamine synthetase activities in wheat
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Effects of experimental warming on peroxidase, nitrate reductase and glutamine synthetase activities in wheat

L. Argentel-Martínez¹², J. Garatuza-Payán¹³, T. Arredondo⁴, E.A. Yépez¹³*

¹Instituto Tecnológico de Sonora, 5 de febrero, 818 Sur, Col. Centro, Cd. Obregón, Sonora, México, CP: 85000
²Instituto Tecnológico del Valle del Yaqui, Calle 600, Block 611, Bácum, San Ignacio Río Muerto, Sonora, México, CP: 85275
³Laboratorio Nacional de Geoquímica y Mineralogía, Sede Regional Sur de Sonora, 5 de febrero, 818 Sur, Col. Centro, Cd. Obregón, Sonora, México, CP: 85000
⁴Instituto Potosino de Investigación Científica y Tecnológica. Camino a la Presa San José 2055, Col. Lomas, Sección 4, San Luis Potosí, México, CP: 78216
*Corresponding author: enrico.yepez@itson.edu.mx

Abstract:

Given the effects of climate change and its significant consequences on plant productivity, it is necessary to evaluate the enzymatic responses of the most important crops such as wheat (Triticum durum L.). We examined the response of foliar peroxidase activity, nitrate reductase, and glutamine synthetase to experimental increments of temperature (+2 °C) under field conditions following conventional agricultural practices. Foliar samples, in both control and warming treatments were taken during growth, tillering and flowering phenophases to test the peroxidase activity. Similarly, nitrate reductase, glutamine synthetase activities, and glutamine content were measured during the heading phenophase. Due to the effects of experimental warming, peroxidase activity significantly increased. The nitrate reductase activity was also higher in the warming treatment, suggesting a high nitrogen metabolism efficiency. Whereas, the increase observed in the glutamine synthetase activity, and consequently the glutamine content, evidenced a biochemical signal of an early senescence due to the effect of warming.

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1072–1083 M. Linda, G. Künzel and M. Hromasová
A dynamic model of electric resistor’s warming and its verification by micro-thermocouples
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A dynamic model of electric resistor’s warming and its verification by micro-thermocouples

M. Linda, G. Künzel and M. Hromasová*

Czech University of Life Sciences in Prague, Faculty of Engineering, Department of Electrical Engineering and Automation, Kamýcká 129, CZ165 21 Prague, Czech Republic
*Correspondence: hromasova@tf.czu.cz

Abstract:

The object of research is a resistor, a real electronic component, loaded by constant or impulse power. As a first approximation, resistor follows 1st order dynamic system, i.e. heating of the hottest spot on its surface is exponential to the power increase. The validity of this model is confirmed by measurements in a constant power loading regime. In an impulse power loading, it is only valid when the pulse duration approaches time constant of the resistor. The aim of this article is to show more credible model warming of the resistor, which is valid even for the case of pulse duration (ms) much shorter than the time constant of the resistor. The model can reveal an overload which does not lead to destruction of the resistor. Dynamic model of the resistor is based on its construction. Typically, an insulating ceramic rod is coated with a resistive layer connected with outlet wires on both sides, all being coated with insulating lacquer layer. The resistive layer is a source of heat flow. Formulation of the model comes from general power balance in a form of three differential equations and it is solved using Scilab. The input variable is the impulse power and the outputs are temperature changes in the ceramic rod, the resistive layer and the lacquer layer, compared to the ambient temperature. The simulation allows to determine solutions for various parameters including very short power pulses, which are confirmed experimentally.

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