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Papers by Ana Martínez Tejero

Research paper thumbnail of Ciencias sociales : propuesta curricular

Research paper thumbnail of Qué verde era mi patio

Research paper thumbnail of Escribir para comprender

Research paper thumbnail of Cushing Syndrome and Suppression of the Hypothalamic-Pituitary-Adrenal Axis After Chronic Use of Topical Glucocorticoids

The Endocrinologist, 2008

Topical and inhaled corticoids are considered to be safe even though some reports point out the r... more Topical and inhaled corticoids are considered to be safe even though some reports point out the risks, especially in children. We describe 2 adults in whom the chronic use of topical steroids led to Cushing syndrome. Patients treated with potent topical corticoids should be informed about the possibility of developing Cushing syndrome. Adrenal reserve should be monitored in those patients treated with glucocorticoids for long periods, regardless of the administration route.

Research paper thumbnail of Experimental study on the cooling capacity of a radiant cooled ceiling system

Energy and Buildings, 2012

Nowadays, radiant ceiling systems can be considered among the technologies capable of meeting sus... more Nowadays, radiant ceiling systems can be considered among the technologies capable of meeting sustainable heating and cooling requirements. In order to adequately address design and simulation issues concerning these systems, correct evaluation of the heat transfer process is needed. The aim of this research is to present further evidence on the cooling capacity and heat transfer coefficients for a cooled radiant ceiling, assuring adequate thermal comfort levels in those possible different operation conditions. An experimental setup into a climate test room was developed and used to derive convenient results. The obtained values revealed that heat transfer evaluations on the basis of operative temperature as the unique reference temperature and corresponding total coefficient are not appropriate in real situations, but considering radiant and convective phenomena separately is strongly recommended.

Research paper thumbnail of Comparative study between a ceramic evaporative cooler (CEC) and an air-source heat pump applied to a dwelling in Spain

Energy and Buildings, 2010

The study described in this paper aims to evaluate comparatively the interest of an implementatio... more The study described in this paper aims to evaluate comparatively the interest of an implementation of a ceramic evaporative cooler (CEC) compared to the use of a conventional device such as an air-source heat pump. This comparison is presented in three closely related ways: energy consumption, environmental impact and economic costs. This analysis is based on the hypothetical cooling of a specific room in a dwelling in six Spanish cities, each characterised by a different climate. The behaviour of the CEC in each climate is determined experimentally, reproducing the typical air conditions by an air-treatment unit. The total cooling demand in each city during the summer months is obtained from the data of the thermal load evolution in the room, provided by thermal load calculation software.

Research paper thumbnail of Influence of constructive parameters on the performance of two indirect evaporative cooler prototypes

Applied Thermal Engineering, 2013

Two equally-sized cross-flow heat exchanger prototypes have been designed with a total heat excha... more Two equally-sized cross-flow heat exchanger prototypes have been designed with a total heat exchange area of 6 m 2 and 3 m 2 respectively, constructed with polycarbonate hollow panels of different cross-section. They are connected into a heat recovery cycle within the whole experimental setup constructed for the tests, which mainly consists of: an Air Handling Unit to simulate the outdoor airstream conditions, a conditioned climate chamber, and a water circuit to provide the water supply required. They have been experimentally characterised in two operating modes in order to determine how evaporative cooling improves heat recovery in each case, focusing on the influence of modifying the constructive characteristics. To perform the evaporative cooling process, water is supplied to the exhaust airstream. Results are studied considering how constructive issues, outdoor air volume flow rate and temperature, as well as operating mode influence on the performance obtained. An Analysis of Variance shows how outdoor airflow has a key role in the performance of the systems; whereas entering outdoor air temperature determines cooling capacities. Improvements introduced by larger heat exchange areas compensate with their corresponding smaller cross sections, which hinder water-air distribution on the exhaust air side of the heat exchanger. Finally, these small devices achieve cooling capacities of up to 800 W, being able to partly support ventilation load and achieving around 50% of energy saving in ventilation cooling.

Research paper thumbnail of Experimental characterisation of an indirect evaporative cooling prototype in two operating modes

Applied Energy, 2012

The present paper aims to describe the experimental study developed to characterize an indirect e... more The present paper aims to describe the experimental study developed to characterize an indirect evaporative cooling system made of polycarbonate, designed and manufactured by the Thermal Engineering Group of the University of Valladolid; as well as to introduce the main results obtained. The prototype is characterized by a total heat exchange area of 6 m 2 and is installed in a heat recovery cycle in the experimental setup constructed in the laboratory. This setup mainly consists of: an AHU that enables the reproduction of the different climatic conditions to be tested; a climatic chamber where comfort conditions are to be achieved; a circuit to supply water during one of the operating modes; and the due ducts and measurement probes to properly connect the whole system and register the evolution of the interesting parameters. Two operating modes are performed. In the first one, exhaust air from the climate chamber, in comfort conditions, goes through one side of the heat exchanger, producing heat transfer from the outdoor air stream through the plastic walls of the system. In the second case, an evaporative cooling mode is implemented by supplying water to the exhaust airstream. Results obtained show that heat transfer through the heat exchanger polycarbonate wall improves in the evaporative cooling mode. Furthermore, both cooling capacity and thermal effectiveness of the system also increase in the second case. Moreover, global heat transfer coefficient and cooling capacity are improved by higher outdoor air volume flow rates. Finally, higher outdoor air temperatures imply better cooling capacities and thermal effectiveness.

Research paper thumbnail of Ciencias sociales : propuesta curricular

Research paper thumbnail of Qué verde era mi patio

Research paper thumbnail of Escribir para comprender

Research paper thumbnail of Cushing Syndrome and Suppression of the Hypothalamic-Pituitary-Adrenal Axis After Chronic Use of Topical Glucocorticoids

The Endocrinologist, 2008

Topical and inhaled corticoids are considered to be safe even though some reports point out the r... more Topical and inhaled corticoids are considered to be safe even though some reports point out the risks, especially in children. We describe 2 adults in whom the chronic use of topical steroids led to Cushing syndrome. Patients treated with potent topical corticoids should be informed about the possibility of developing Cushing syndrome. Adrenal reserve should be monitored in those patients treated with glucocorticoids for long periods, regardless of the administration route.

Research paper thumbnail of Experimental study on the cooling capacity of a radiant cooled ceiling system

Energy and Buildings, 2012

Nowadays, radiant ceiling systems can be considered among the technologies capable of meeting sus... more Nowadays, radiant ceiling systems can be considered among the technologies capable of meeting sustainable heating and cooling requirements. In order to adequately address design and simulation issues concerning these systems, correct evaluation of the heat transfer process is needed. The aim of this research is to present further evidence on the cooling capacity and heat transfer coefficients for a cooled radiant ceiling, assuring adequate thermal comfort levels in those possible different operation conditions. An experimental setup into a climate test room was developed and used to derive convenient results. The obtained values revealed that heat transfer evaluations on the basis of operative temperature as the unique reference temperature and corresponding total coefficient are not appropriate in real situations, but considering radiant and convective phenomena separately is strongly recommended.

Research paper thumbnail of Comparative study between a ceramic evaporative cooler (CEC) and an air-source heat pump applied to a dwelling in Spain

Energy and Buildings, 2010

The study described in this paper aims to evaluate comparatively the interest of an implementatio... more The study described in this paper aims to evaluate comparatively the interest of an implementation of a ceramic evaporative cooler (CEC) compared to the use of a conventional device such as an air-source heat pump. This comparison is presented in three closely related ways: energy consumption, environmental impact and economic costs. This analysis is based on the hypothetical cooling of a specific room in a dwelling in six Spanish cities, each characterised by a different climate. The behaviour of the CEC in each climate is determined experimentally, reproducing the typical air conditions by an air-treatment unit. The total cooling demand in each city during the summer months is obtained from the data of the thermal load evolution in the room, provided by thermal load calculation software.

Research paper thumbnail of Influence of constructive parameters on the performance of two indirect evaporative cooler prototypes

Applied Thermal Engineering, 2013

Two equally-sized cross-flow heat exchanger prototypes have been designed with a total heat excha... more Two equally-sized cross-flow heat exchanger prototypes have been designed with a total heat exchange area of 6 m 2 and 3 m 2 respectively, constructed with polycarbonate hollow panels of different cross-section. They are connected into a heat recovery cycle within the whole experimental setup constructed for the tests, which mainly consists of: an Air Handling Unit to simulate the outdoor airstream conditions, a conditioned climate chamber, and a water circuit to provide the water supply required. They have been experimentally characterised in two operating modes in order to determine how evaporative cooling improves heat recovery in each case, focusing on the influence of modifying the constructive characteristics. To perform the evaporative cooling process, water is supplied to the exhaust airstream. Results are studied considering how constructive issues, outdoor air volume flow rate and temperature, as well as operating mode influence on the performance obtained. An Analysis of Variance shows how outdoor airflow has a key role in the performance of the systems; whereas entering outdoor air temperature determines cooling capacities. Improvements introduced by larger heat exchange areas compensate with their corresponding smaller cross sections, which hinder water-air distribution on the exhaust air side of the heat exchanger. Finally, these small devices achieve cooling capacities of up to 800 W, being able to partly support ventilation load and achieving around 50% of energy saving in ventilation cooling.

Research paper thumbnail of Experimental characterisation of an indirect evaporative cooling prototype in two operating modes

Applied Energy, 2012

The present paper aims to describe the experimental study developed to characterize an indirect e... more The present paper aims to describe the experimental study developed to characterize an indirect evaporative cooling system made of polycarbonate, designed and manufactured by the Thermal Engineering Group of the University of Valladolid; as well as to introduce the main results obtained. The prototype is characterized by a total heat exchange area of 6 m 2 and is installed in a heat recovery cycle in the experimental setup constructed in the laboratory. This setup mainly consists of: an AHU that enables the reproduction of the different climatic conditions to be tested; a climatic chamber where comfort conditions are to be achieved; a circuit to supply water during one of the operating modes; and the due ducts and measurement probes to properly connect the whole system and register the evolution of the interesting parameters. Two operating modes are performed. In the first one, exhaust air from the climate chamber, in comfort conditions, goes through one side of the heat exchanger, producing heat transfer from the outdoor air stream through the plastic walls of the system. In the second case, an evaporative cooling mode is implemented by supplying water to the exhaust airstream. Results obtained show that heat transfer through the heat exchanger polycarbonate wall improves in the evaporative cooling mode. Furthermore, both cooling capacity and thermal effectiveness of the system also increase in the second case. Moreover, global heat transfer coefficient and cooling capacity are improved by higher outdoor air volume flow rates. Finally, higher outdoor air temperatures imply better cooling capacities and thermal effectiveness.