2,742 research outputs found
Maximal oxygen consumption in Mexican university studenst: Correlation between five predictive tests
El objetivo de este estudio fue determinar si existen diferencias en los valores
de VO2max indirecto obtenido con cinco pruebas físicas: UTMM, VAM-EVAL, Ida-
Vuelta, 1000 m y Ramsbottom. Los sujetos fueron hombres mexicanos en edad
universitaria sin entrenamiento previo y sin experiencia en deportes, con los
siguientes parámetros: edad 19,33 ± 1,09 años (media ± 1 desviación estándar),
peso 68,47 ± 9,93 kg, estatura 1,71 ± 0,06 m e IMC 23,62 ± 2,82. El VO2max indirecto
(ml/kg/min, media ± 1 error estándar) por prueba fue de: 44,26 ± 3,74 para UMTT,
44,14 ± 3,01 para VAM-EVAL, 42,78 ± 2,80 para Ida y vuelta, 44,92 ± 2,33 para
1000 m y 42,67 ± 2,96 para Ramsbotton. No se encontraron diferencias
significativas entre el VO2max indirecto obtenido por los sujetos de estudio en las
cinco pruebas. Concluimos que las cinco pruebas son equivalentes y pueden ser
usadas indistintamente para evaluar el VO2max indirectoThe objetive of this study was determining if there are differences in the
measurement of indirect VO2max among five different physical tests: UMTT, VAMEVAL,
20 MST, 1000 m and Ramsbottom. The subjects were Mexican college-age
men without previous training and without sport experience with the following
parameters: years 19,33±1,09 (mean ± 1 standard deviation), weight 68,47 ± 9,93
kg, height 1,71 ± 0,06 m and body mass index 23,62 ± 2,82. VO2max indirect
(ml/kg/min, average ± 1 standard error) by test were: 44,26 ± 3,74 for UMTT, 44,14
± 3,01 for VAM-EVAL, 42,78 ± 2,80 for 20 MST, 44,92 ± 2,33 for 1000 m and 42,67
± 2,96 for Ramsbotton. We do not detect significant differences between the
indirect VO2max obtained in the five tests. We concluded that the five tests are
equivalent and can be used interchangeably to assess the indirect VO2ma
Biosystematic contributions to Agromyzidae (Diptera)
La familia Agromyzidae incluye las especies de dípteros minadores más importantes para la Agricultura. Se conocen 2900 especies en el mundo de las cuales cerca del 7% se consideran de interes agronómico. A pesar de la alta especificidad de Agromyzidae por sus plantas hospedadoras, se ha observado en las últimas décadas un incremento significativo de la oligofagia y polifagia de muchas especies asociado al cambio constante producido en los ecosistemas y al incremento del cultivo intensivo.
El conocimiento de la biodiversidad de Agromyzidae es uno de los principales factores a tener en cuenta en el control de plagas presentes y futuras. Como resultado del estudio sistemático realizado en tres parques naturales de la España oriental: "Tinença de Benifassà" (Castellón), "Font Roja" (Alicante) y "Lagunas de La Mata-Torrevieja" (Alicante) se presentan nuevos datos faunísticos incluidos en 6 géneros de Agromyzidae. Se citan por primera vez 13 nuevas especies capturadas con trampa Malaise en España: Agromyza anthracina Meigen, 1830; A. bromi Spencer, 1966; A. hiemalis Becker, 1908; A. megalopsis Hering, 1933; Aulagromyza luteoscutellata (de Meijere, 1924); Au. similis (Brischke, 1880); Au. trivitatta (Loew, 1873); Liriomyza graminivora Hering, 1949; Melanagromyza eupatorii Spencer, 1957; M. spinulosa Spencer, 1974; Phytobia cerasiferae (Kangas, 1955); Ph. lunulata (Hendel, 1920) y Pseudonapomyza palliditarsis Cerny, 1992. Se incluye información general de las plantas hospedadoras y su distribución geográfica.
Se cita una nueva plaga dentro de la familia Agromyzidae, Melanagromyza sojae (Zehnter, 1900). Este minador de tallos fue capturado con trampa Malaise en el parque de la "Tinença de Benifassà". Se incluye información de la distribución, daño, control, plantas hospedadoras, biología y ecología de esta plaga. A su vez, se indican las reglas de identificación para su distinción del resto de minadores de Agromyzidae sobre soja en Europa.Gil Ortiz, R. (2010). Biosystematic contributions to Agromyzidae (Diptera) [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/7326Palanci
Techno-Economic Analysis of Rural 4th Generation Biomass District Heating
Biomass heating networks provide renewable heat using low carbon energy sources.
They can be powerful tools for economy decarbonization. Heating networks can increase heating
efficiency in districts and small size municipalities, using more efficient thermal generation
technologies, with higher efficiencies and with more efficient emissions abatement technologies.
This paper analyzes the application of a biomass fourth generation district heating, 4GDH
(4th Generation Biomass District Heating), in a rural municipality. The heating network is designed
to supply 77 residential buildings and eight public buildings, to replace the current individual diesel
boilers and electrical heating systems. The development of the new fourth district heating generation
implies the challenge of combining using low or very low temperatures in the distribution network
pipes and delivery temperatures in existing facilities buildings. In this work biomass district heating
designs based on third and fourth generation district heating network criteria are evaluated in terms
of design conditions, operating ranges, effect of variable temperature operation, energy efficiency
and investment and operating costs. The Internal Rate of Return of the different options ranges
from 6.55% for a design based on the third generation network to 7.46% for a design based on the
fourth generation network, with a 25 years investment horizon. The results and analyses of this
work show the interest and challenges for the next low temperature DH generation for the rural area
under analysis
The Ammonia Looping System for Mid-Temperature Thermochemical Energy Storage
Thermochemical reactions have a great potential for energy storage and transport. Their application to solar
energy is of utmost interest because the possibility of reaching high energy densities and seasonal storage
capacity. In this work, thermochemical energy storage of Concentrated Solar Power (CSP) based on an
ammonia looping (AL) system is analysed. The AL process for energy storage is based on the reversible reaction
of ammonia to produce hydrogen and nitrogen. Concentrating solar energy is used to carry out the
decomposition endothermic reaction at temperatures around 650 ºC, which fits in the range of currently
commercial CSP plants with tower technology. The stored energy is released through the reverse exothermic
reaction. Our work is focused on energy integration in the system modelled by pinch analysis to optimize the
process performance and competitiveness. As result a novel configuration is derived which is able to recover
high-temperature heat for electricity production with a thermal-to-electric efficiency up to 27 %. The current study
shows a clear interest of the system from an energy integration perspective. Further research should be
conducted to access the potential for commercial applications
Pseudonapomyza benifassae sp. n. (Diptera: Agromyzidae), a new species from Eastern Spain
Systematic and ecological aspects of a new species Pseudonapomyza benifassae Gil-Ortiz sp. n. (Diptera: Agromyzidae) from Spain, are given. A study of faunistic data of European Pseudonapomyza is made. P. palliditarsis Černý is recorded for the first time in Spain
Effects of Fe-EDDHA Chelate Application on Evolution of Soil Extractable Iron, Copper, Manganese and Zinc
[EN] Up to date, soil application of synthetic chelates is the most effective mean of controlling iron (Fe) deficiency chlorosis in many crops. The responses of three representative soils (I, II, and III) of a large orchard area (Ribbra Alta del Jucar) to the application of three commercial Fe-EDDHA chelates (Sequestrene 138 Fe G-100, Group Carla Val F.E.A 6 Superior and Ferrishell plus) at 100 (D1) and 200 mug Fe/kg of soil (132) were analyzed. Extractable concentrations of Fe, copper (Cu), manganese (Mn), and zinc (Zn) were determined at 7, 14, 21, 42, and 71 days after the application. Data were subjected to multifactor ANOVA to analyze the effects of time, dose, soil, and chelate type on Fe, Cu, Mn, and Zn concentrations. Soil type affected the recovery percentage of Fe by DTPA extraction. The extractable Fe increased to 40-60 mg Fe/kg of soil by the D1 dose and to 70-100 mg Fe/kg of soil by the D2 dose for soils I and II. However, in the case of soil III, recovery increased to 60-80 mg Fe/kg of soil for D1 and 100-140 mg Fe/kg of soil for D2. As the pH of the three soils was similar, this recovery difference is attributed to the differing textural compositions of the soils. The extractable concentrations of Fe increased In the sandy loam soil in contrast to-the clay loam soils. The Fe-EDDHA formula did not affect significantly, extractable Fe concentration. Increases in-the extract able Cu and Mn were observed after Fe-EDDHA soil application. These increases could be due to changes in the redox potential that alters the form and solubility of some metals, possibly affecting the metal-chelate equilibrium. In the case of Zn, the variation in Zn concentration is hardly appreciable, with Fe preventing effective Zn chelation. No difference in effectiveness has been found between the Fe-EDDHA formula brands used in this experiment.Gil-Ortiz, R.; Bautista, I. (2004). Effects of Fe-EDDHA Chelate Application on Evolution of Soil Extractable Iron, Copper, Manganese and Zinc. Communications in Soil Science and Plant Analysis. 35(3-4):559-570. https://doi.org/10.1081/CSS-120029732S559570353-4Aboulroos, S. A. (1981). Reaction of EDTA, DTPA, and EDDHA Complexes of Zinc, Copper, and Manganese with a Calcareous Soil. Zeitschrift für Pflanzenernährung und Bodenkunde, 144(2), 164-173. doi:10.1002/jpln.19811440207Inskeep, W. P., & Bloom, P. R. (1987). Soil Chemical Factors Associated with Soybean Chlorosis in Calciaquolls of Western Minnesota
1. Agronomy Journal, 79(5), 779-786. doi:10.2134/agronj1987.00021962007900050005xLindsay , W.L. 1979.Chemical Equilibria in Soil449 ppNew York: Wiley-Interscience.Hernandez‐Apaolaza, L., Gárate, A., & Lucena, J. J. (1995). Efficacy of commercial Fe(III)‐EDDHA and Fe(III)‐EDDHMA chelates to supply iron to sunflower and corn seedlings. Journal of Plant Nutrition, 18(6), 1209-1223. doi:10.1080/01904169509364973De Liñan , C. 2000.Vademecum de Productos Fitosanitarios y Nutricionales,, 17th Ed. 655 ppMadrid, Spain: Ediciones Agrotécnica.Álvarez-Fernández , A. 2000.Calidad y Eficacia de Quelatos Férricos (FeEDDHA, FeEDDHMA, FeEDDHSA y FeEDDCHA) Como Fertilizantes655 ppMadrid, Spain: Universidad Autónoma de Madrid. Tesis DoctoralAlva, A. K. (1992). Solubility and iron release characteristics of iron chelates and sludge products. Journal of Plant Nutrition, 15(10), 1939-1954. doi:10.1080/01904169209364449Lindsay, W. L., & Norvell, W. A. (1978). Development of a DTPA Soil Test for Zinc, Iron, Manganese, and Copper. Soil Science Society of America Journal, 42(3), 421-428. doi:10.2136/sssaj1978.03615995004200030009xFollett, R. H., & Lindsay, W. L. (1971). Changes in DTPA-Extractable Zinc, Iron, Manganese, and Copper in Soils Following Fertilization. Soil Science Society of America Journal, 35(4), 600-602. doi:10.2136/sssaj1971.03615995003500040034xAndréu, J. S., Jordá, J., & Juárez, M. (1991). Reactions of FeEDTA and FeEDDHA applied to calcareous soils. Iron Nutrition and Interactions in Plants, 57-62. doi:10.1007/978-94-011-3294-7_6Belly, R. T., Lauff, J. J., & Goodhue, C. T. (1975). Degradation of Ethylenediaminetetraacetic Acid by Microbial Populations from an Aerated Lagoon. Applied Microbiology, 29(6), 787-794. doi:10.1128/aem.29.6.787-794.1975Jones, S. S., & Long, F. A. (1952). Complex Ions from Iron and Ethylenediaminetetraacetate: General Properties and Radioactive Exchange. The Journal of Physical Chemistry, 56(1), 25-33. doi:10.1021/j150493a007HILL-COTTINGHAM, D. G. (1955). Photosensitivity of Iron Chelates. Nature, 175(4451), 347-348. doi:10.1038/175347a0Wallace, A., & Lunt, O. R. (1956). Reactions of Some Iron, Zinc, and Manganese Chelates in Various Soils1. Soil Science Society of America Journal, 20(4), 479. doi:10.2136/sssaj1956.03615995002000040009xBarona, A., Aranguiz, I., & Elias, A. (1999). Zinc and copper distribution in soils and their removal by chelating extraction. Journal of Chemical Technology & Biotechnology, 74(7), 700-708. doi:10.1002/(sici)1097-4660(199907)74:73.0.co;2-fNabhan, H. M., Vanderdeelen, J., & Cottenie, A. (1977). Chelate behaviour in saline-alkaline soil conditions. Plant and Soil, 46(3), 603-618. doi:10.1007/bf00015919Hill-Cottingham, D. G., & Lloyd-Jones, C. P. (1957). Behaviour of iron chelates in calcareous soils. Plant and Soil, 8(3), 263-274. doi:10.1007/bf01666161Norvell, W. A., & Lindsay, W. L. (1969). Reactions of EDTA Complexes of Fe, Zn, Mn, and Cu with Soils. Soil Science Society of America Journal, 33(1), 86-91. doi:10.2136/sssaj1969.03615995003300010024
The Algarve climatophilous vegetation series – Portugal: a base document to the planning, management and nature conservation Les séries de végètation climatophiles de l’Algarve - Portugal: un document de base pour la planification, gestion et conservation de la nature
This work was developed as part of PhD research devoted to the flora and vegetation of the Caldeirão and
Monchique mountains that aims to identify the vegetation climatophilous series and use them as an environmental
diagnosis of Algarve administrative province phyto-ecological subregions. Biogeographic and bioclimatic considerations
are presented, as well as the study area pedological and lithological characterization. For each of the seven
climatophilous series the dynamic and catenal behaviours, as well as the main characteristic plants that constitute the
successional stages, are given. The corresponding patrimonial value is studied
Magnetic frustration and fractionalization in oligo(indenoindenes)
Poly(indenoindenes) are {\pi}-conjugated ladder carbon polymers with
alternating hexagons and pentagons hosting one unpaired electron for each
five-membered ring in the open-shell limit. Here we study the main magnetic
interactions that are present in finite oligo(indenoindenes) (OInIn),
classifying the six possible isomers in two different classes of three isomers
each. One class can be rationalized by frustrated S = 1/2 Heisenberg chains,
with ferromagnetic interactions between neighbour sites and antiferromagnetic
interactions between the next neighbours. The other class is characterized by
the more trivial antiferromagnetic order. Employing several levels of theory we
further show that the ground state of one of the isomers is a valence-bond
solid (VBS) of ferromagnetic dimers (S = 1). This is topologically similar to
that of the Affleck-Kennedy-Lieb-Tasaki (AKLT) model, which is known to show
fractional S = 1/2 states at the edges
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