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Santa Tecla, El Salvador

Wilczek A.,Polish Academy of Sciences | Szyplowska A.,Polish Academy of Sciences | Skierucha W.,Polish Academy of Sciences | Ciesla J.,Polish Academy of Sciences | And 2 more authors.
Sensors (Switzerland) | Year: 2012

This paper presents the application of a frequency-domain reflectometry (FDR) sensor designed for soil salinity assessment of sandy mineral soils in a wide range of soil moisture and bulk electrical conductivity, through the determination of soil complex dielectric permittivity spectra in the frequency range 10-500 MHz. The real part of dielectric permittivity was assessed from the 380-440 MHz, while the bulk electrical conductivity was calculated from the 165-325 MHz range. The FDR technique allows determination of bulk electrical conductivity from the imaginary part of the complex dielectric permittivity, without disregarding the dielectric losses. The soil salinity status was determined using the salinity index, defined as a partial derivative of the soil bulk electrical conductivity with respect to the real part of the soil complex dielectric permittivity. The salinity index method enables determining the soil water electrical conductivity value. For the five sandy mineral soils that have been tested, the relationship between bulk electrical conductivity and the real part of dielectric permittivity is essentially linear. As a result, the salinity index method applied for FDR measurements may be adapted to field use after examination of loam and clayey soils. © 2012 by the authors; licensee MDPI, Basel, Switzerland. Source


Polytechnic University of El Salvador | Entity website


Gulyayev Y.G.,National Metallurgical Academy of Ukraine | Mamuzic I.,University of Zagreb | Shyfrin Y.I.,Tube Metallurgical Company | Bursak M.,Polytechnic University of El Salvador | Garmashev D.Y.,OJSC INTERPIPE NTZ
Metalurgija | Year: 2011

The article first give a review more of hundret years long history of seamless steel tube production, especially during the last 15-20 years of the 20th century. Prolongation, article give technological indices for 4 mills (automatical, continuous mill, pilger, Assel), and perfectation of processes seamless steel tubes production at the begining of 21st century. Source


This paper is focused on the area of motivation and motivational programs for employees in the wood industry and in other manufacturing enterprises (engineering, food, chemical and textile). The main objective of this paper is to compare the motivation of employees with in manufacturing companies of various categories. We analyzed the current state of motivation of employees within manufacturing companies throughout Slovakia. The analysis was made of 21 enterprises with 2 576 employees in different job positions. The order of importance was made for 30 selected motivational factors in wood industry and other manufacturing enterprises. The evaluation of statistical correlation between the two compared groups was made by use of the Spearman correlation coefficient, by which statistical dependence was defined between the category of workers and the category of technical-economic employees. The results show fundamental difference of the importance of motivational factors within technical and marketing staff of woodworking companies and other manufacturing companies. In the category of workers, diversity of the importance of motivational factors is less significant. Our analysis showed that in a long period of time all employees keep their motivation at a constant level. Source


Kandrik R.,Polytechnic University of El Salvador | Olah B.,Polytechnic University of El Salvador
Moravian Geographical Reports | Year: 2010

Land use developments and changes in the central part of the Spiš region since the 18th century are discussed in this paper. Using the ArcGIS 9.x software, available aerial photographs and historical maps were processed and land use categories were identified for five points in time. The areas with stable land use, as well as those with various intensities of land use change, were assessed. The main trends in land use and their locations were identified. The analysis revealed several similarities with comparable neighbouring regions, but also some regional specification. © INSTITUTE OF GEONICS ASCR, v.v.i. 2010. Source

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