<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>0253-5785</journal-id>
<journal-title><![CDATA[Centro Agrícola]]></journal-title>
<abbrev-journal-title><![CDATA[Ctro. Agr.]]></abbrev-journal-title>
<issn>0253-5785</issn>
<publisher>
<publisher-name><![CDATA[Editorial Feijóo, Universidad Central de Las Villas]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S0253-57852021000200057</article-id>
<title-group>
<article-title xml:lang="es"><![CDATA[Modelo simplificado para el cálculo de grados-día con escala de tiempo variable]]></article-title>
<article-title xml:lang="en"><![CDATA[Simplified model for the calculation of degrees-day with variable time scale]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Rodríguez Santos]]></surname>
<given-names><![CDATA[Ovidio]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Cruz Fonticiella]]></surname>
<given-names><![CDATA[Oscar]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Leyva Céspedes]]></surname>
<given-names><![CDATA[Alfredo]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Universidad Central &#8220;Marta Abreu&#8221; de Las Villas Centro de Estudios Energéticos y Tecnologías Ambientales ]]></institution>
<addr-line><![CDATA[Santa Clara Villa Clara]]></addr-line>
<country>Cuba</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>06</month>
<year>2021</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>06</month>
<year>2021</year>
</pub-date>
<volume>48</volume>
<numero>2</numero>
<fpage>57</fpage>
<lpage>65</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://scielo.sld.cu/scielo.php?script=sci_arttext&amp;pid=S0253-57852021000200057&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://scielo.sld.cu/scielo.php?script=sci_abstract&amp;pid=S0253-57852021000200057&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://scielo.sld.cu/scielo.php?script=sci_pdf&amp;pid=S0253-57852021000200057&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="es"><p><![CDATA[RESUMEN En este trabajo, los autores proponen un modelo simplificado para el cálculo de grados-día para diferentes escalas de tiempo y temperatura base variable. Se resume en seis expresiones que dan como resultado un modelo simple, compacto y fácil de programar en cualquier hoja de cálculo. Su principal ventaja radica en el cálculo integrado de grados-día para escalas de tiempo: diario, mensual y anual, lo que lo hace atractivo para su aplicación en sectores estratégicos de la economía como el electro- energético, de la construcción y el de la agricultura. Es aplicable a regiones para las que previamente se han fijado los valores de los coeficientes de regresión, necesarios para la determinación de la temperatura equivalente, (parámetro definido por los autores, válido para una determinada región geográfica). Estos coeficientes han sido determinados para las áreas aledañas a la estación meteorológica Yabú, perteneciente a la provincia de Villa Clara, para el territorio que abarca dicha provincia y para todo el territorio del archipiélago cubano. Se presentan dos versiones del modelo, una versión base y una extendida; la primera utiliza como variables de entrada la temperatura media, la temperatura media mínima y la temperatura media máxima, según la escala de tiempo a considerar, la segunda permite su aplicación introduciendo la temperatura media como única variable de entrada. La diferencia de precisión entre estas versiones no es significativa, por lo que ambas son recomendables.]]></p></abstract>
<abstract abstract-type="short" xml:lang="en"><p><![CDATA[ABSTRACT In this paper, the authors propose a simplified model for the calculation of degree days for different time scales and variable base temperature. It is summarized in six expressions that result in a simple, compact and easy to program model in any spreadsheet. Its main advantage lies in the integrated calculation of degree days for daily, monthly and annual time scales, which makes it attractive for its application in strategic sectors of the economy such as the electro-energy, construction and agriculture sectors. It is applicable to regions for which the values of the regression coefficients necessary for the determination of the equivalent temperature (parameter defined by the authors, valid for a given geographical region) have been previously fixed. These coefficients have been determined for the areas surrounding the Yabú meteorological station, belonging to the province of Villa Clara, for the territory covered by this province and for the whole territory of the Cuban archipelago. Two versions of the model are presented, a base version and an extended one; the first one uses as input variables the mean temperature, the mean minimum temperature and the mean maximum temperature, according to the time scale to be considered, the second one allows its application by introducing the mean temperature as the only input variable. The difference in accuracy between these versions is not significant, so both are recommended.]]></p></abstract>
<kwd-group>
<kwd lng="es"><![CDATA[agricultura]]></kwd>
<kwd lng="es"><![CDATA[gestión energética]]></kwd>
<kwd lng="es"><![CDATA[integral térmica]]></kwd>
<kwd lng="es"><![CDATA[tiempo térmico]]></kwd>
<kwd lng="es"><![CDATA[unidades de calor]]></kwd>
<kwd lng="en"><![CDATA[agriculture]]></kwd>
<kwd lng="en"><![CDATA[energy management]]></kwd>
<kwd lng="en"><![CDATA[thermal integral]]></kwd>
<kwd lng="en"><![CDATA[thermal time]]></kwd>
<kwd lng="en"><![CDATA[heat units]]></kwd>
</kwd-group>
</article-meta>
</front><back>
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