En Memoria Arturo Velasco Negueruela

Sin resume

Nuevos datos sobre la composición química de aceites esenciales procedentes de tomillos ibéricos.

VILLAscO-NEGUERLELA, A. & PÉREZ-ALoNso, M. J. 1990. New results on the chemical composition of essential oil 5 from iberian species of Thymus. Bat. Complutensis, 16: 9 1-97 Wc have studied by gas cbromatography and infrared spectroscopy the qualitative and quantitative composition of the volatile oils of Tu. loscosil Willk., Ph. carnosas Hoiss., Th. campharatus Roffinanns. & Link, Ph. mastigophorus Lacaita y Ph. zygis Loefl. subsp. zygís.VELASCO-NEGEERUELA, A. & PÉREz-ALoNso, M. J. 1990. Nuevos datos sobre la composición química de aceites esenciales procedentes de tomillos ibéricos. Bat. Complutensis, 16: 91-97. Se estudia en este trabajo la composición química de los aceites esenciales de Thymus lascasii Willk., Ph. carnosus Boiss., Ph. caniphoratus Iloffmanns. & Link, TA. mastigophorus Lacaita y Ph. zvgis Loefl. subsp. zvgis. Se ha utilizado la cromatografia gas-liquido y la espectroscopia infrarroja para la identificación de los componente

Variación de la composición química del aceite esencial de especies del género Santolina L. I: Condiciones de extracción y conservación.

. In tbis paper various factors related with the essential oil composition of aromatic plants like time and extraction procedures, storing and preservation were studied. Some species of Santolina L. were selected. The largest differences were observed in the destillation procedures and minor ones witb the storing and preservation methods.. En la composición del aceite esencial de un determinado taxón intervienen factores extrínsecos, tales como el tiempo y forma de extracción, junto con otros debidos a condiciones de conservación y almacenamiento del aceite extraído en atmósfera inerte. En algunas de las especies del género Santo/ma L. se ha estudiado y observado una distinta incidencia de estos factores. Las mayores diferencias se obtuvieron mediante la variación de la forma de destilación, y las menores, modificando las condiciones de conservación y almacenamiento

Aceites esenciales de tomillos ibéricos, IV. Contribución al estudio quimiotaxonómico (Terpenoides) del género Thymus L.

Realizamos en este trabajo --cuarto de una serie dedicada a la composición química de los aceites esenciales del género Thymus L. que viven en la Península Ibérica-- una revisión quimiotaxonómica de varias secciones de este género, utilizando> además de nuestros datos analíticos, otros bibliográficos.mis is tbe fourth part of a series of papers related with the chemical composition of iberian species of Thymus L. Vapor pliase chromatographic patterns of several species are given. The taxonomic value of the terpenoids are aÑo discussed

Labor Demand and Information Technologies: Evidence for Spain, 1980-2005

Using the EU KLEMS dataset we test the capital-skill complementarity hypothesis in a cross-section of sectors in Spain between 1980 and 2005. We analyze three groups of workers, who are classed according to skill level: high, medium and low. Capital assets have been broken down into ICT (information and communication technologies) assets and non-ICT assets. Acquisition and usage costs of ICT assets declined throughout the period studied, both in absolute terms and relative to the other capital assets and workers. Our principal finding is that the substitutibility between workers and ICT assets falls as worker skill level rises. In fact, the ICT assets were strongly complement with highly skilled workers and were not substitutive with them. Throughout the period analyzed, the fraction of employed medium- and high-skill workers rose by 21% and 12%, respectively, to the disadvantage of low-skill workers. After decomposing these changes, we found that the latter were dominated by an ajustment within sectors more than by a composition effect or adjustment between sectors. These adjustments may be explained by reference to the estimated elasticities of substitution.capital-skill complementarity, ICT, translog cost function, elasticity of substitution.

The profitability of value-added products in dairy farm diversification initiatives

A more open and competitive dairy market has encouraged certain dairy farms to adopt value-adding strategies in order to achieve a higher profitability, which may be important for farms’ survival. This paper investigated the role of some product characteristics in the profitability of value-added products in these farms. For this purpose, we used a unique database of 265 different products commercialized by 49 Spanish dairy farms that offers information on nine attributes of each product. Using hedonic models as a baseline, we examined the influence of these attributes on the margin per liter (ML) of the products. The results of the regression indicated that cheese and yogurt generated 0.688 and 1.518 € more of margin per liter than liquid milk. Similarly, we found a set of attributes that have a positive influence on ML, including possession of a certificate of protected designation of origin (PDO), the milk-type composition (proportion of sheep milk), a longer expiration period, and involvement in direct marketing strategies (DMS). However, other recognized attributes such as organic labeling, maturation period, size of the sales unit and returnable packaging did not have a significant influence on ML. Our findings also showed that firms producing more elaborated products as cheese and yogurt need a lower percentage of their production to cover the fixed costs associated to transformation and commercialization. Overall, our results revealed that the elaboration of value-added dairy products improves the profitability of dairy farms

Ultra-Broadband Directional Couplers Using Microstrip with Dielectric Overlay in Millimeter-Wave Band

Nowadays, millimeter-wave systems are being a key factor to develop wide band applications. In this paper, a directional coupler in millimeter-wave band using dielectric overlay is presented. This leads us to technology aspects, in directional coupler design, are key points to achieve the proper response of the circuit. The coupler proposed in this paper covers the 15-45 GHz band and its response has 15-dB coupling-level, 1-dB coupling-ripple and a reflection coefficient better than 10 dB

Development of tutorials to promote self-directed programming learning: application to postgraduate studies

Most students graduated in Marine Science or other related disciplines (e.g. Geology, Biology, Chemistry) lack the basic background knowledge in scientific programming and modelling (e.g. Matlab, Fortran, Python), necessary in numerical disciplines such as Physical or Coastal Oceanography. Hence, when they enroll for postgraduate studies in Oceanography they are not able to properly follow the lessons related to the above disciplines and generally become discouraged. Trying to meet the needs of those students during the lessons would result in not accomplishing the course’s program, given the fact that MSc programs have concentrated material and are extremely demanding for the students. For this reason, a collaborative effort has been made among various lecturers to develop tutorials in order to promote self-directed learning among the MSc students with the aim of alleviating those deficiencies. These tutorials were applied in two different courses and consisted in: i) a quick-start Matlab guide for NetCDF meteorological and oceanographic data handling and plotting, and ii) the use of a front-end platform for visualising, analysing and evaluating results from the state-of-the-art morphodynamic model XBEACH-G. The above methods helped the students to understand the potential of programming and numerical modelling, as well as, the importance of applying such approaches both in consulting and research-based carriers. Overall, this methodology resulted in a higher level of satisfaction among students because it offered an active, flexible and self reliant learning method that was adapted to each person’s learning pace and difficulties. Finally, the tutorials proved to be an inclusive teaching strategy able to address the needs of students with different backgrounds, learning styles, and abilities, hence providing a more efficient learning environment, in which all students could reach their potential at their own pace and feel equally valued at the end of the course

Galloping instabilities of Z-shaped shading louvers

Modern design of civil constructions such as office blocks, airport terminal buildings, factories, etc. incorporates more and more environmental considerations that lead to, amongst other elements, the use of glazed façades with shading devices to optimize energy consumption. These shading devices, normally slats or louvers, are very flexible structures exposed to the action of wind, and therefore aeroelastic effects such as galloping must be taken into account in their design. A typical cross-section for such elements is a Z-shaped profile made out of a central web and two side wings. The results of a parametric analysis based on static wind tunnel tests and performed on different Z-shaped louvers to determine translational galloping instability regions are presented in this paper

Flavonoides en Musgos: consideraciones quimiosistemáticas.

LÓ¡±z-SÁEZ,JA.. M.J. PÉREZ-ALONSO & A. VELASCO NEGIJERUELA. 1996. Flavonoids in Musci: cheinosystemarie eonsiderations. Bat. Complutensis 21: 9-38. Tbk work confirnis that mosses are not primitive embryo-ptants. They are closely related tovaseu¡ar plants, aecording to their flavonoid counposition.LÓPEz-SÁrz, JA., PÉREZ-ALONSO & A. VELASCO NIIQUERUELA. 1996. Flavonoides en Musgos: consideraciones quimiosistemáticas. Bot. Complutensis 21: 9-38. Se argunienta el significado quíiníosistcinátíco dc la presencia de flavonoides en Musci, y se apoya la propuesta de que los musgos no son embriobiontes primitivos, sino que comparten una fuerte afinidad con las plantas vasculares, habiendo ido bioquimicamente hablando muy paralelos en su evolución