3,209 research outputs found
Ciencia sobre ruedas en Granada. Una experiencia de actualización científica y tecnológica en el aula
Describimos una experiencia de colaboración entre el Parque de las Ciencias de Granada y el centro educativo Ciencias sobre Ruedas de Puerto Rico para llevar a siete centros educativos de Andalucía la tecnología de experimentación asistida por ordenador, EXAO, conectándola con temas de investigación real en el área de química. El proceso comenzó con la formación del profesorado en el uso de esta tecnología dentro de un enfoque de enseñanza orientado hacia la investigación en el aula. La actividad ha estado a cargo de profesores universitarios de Puerto Rico que desarrollan actualmente sus investigaciones de doctorado. Se ofrece la experiencia como un modelo de actualización y formación del profesorado no universitario de ciencias
Sobre la distribución de Riella Helicophylla (Bory et Mont.) Mont en la Península Ibérica
Nueva localidad española de Riella helicophylla (Bory et Mont.) Mont. y mapa de distribución de la especie en la Peninsula Ibérica.A new record of Riella helicophylla from Spain and distributional map in the Iberian Peninsul
A New Species of Cyclobulura (Nematoda: Subuluridae) from Zaedyus pichiy and Chaetophractus vellerosus (Xenarthra: Dasypodidae) in Argentina
Cyclobulura superinae n. sp. collected from Zaedyus pichiy and Chaetophractus vellerosus is herein described as the second species in Cyclobulura Quentin, 1977, and the first subulurid in armadillos. The species is unique in the spur-like structures present at the tip of both spicules, yet they conform to the description of Cyclobulura in the structure of the buccal parts. Specimens of the new species show longer chordal lobes and more conspicuous radial lobes and are smaller than specimens of C. lainsoni. In addition, males of C. superinae exhibit a spur-like process in the distal end of the spicules and a shorter tail (170 vs. 300 µm) with no spine. Finally, the eggs of C. superinae are smaller (60-89 × 45-71 vs. 95-100 × 80-85). To our knowledge, the new species is the first subulurid nematode found in an armadillo
Probabilistic Flexural Fatigue in Plain and Fiber-Reinforced Concrete
The objective of this work is two-fold. First, we attempt to fit the experimental data on the flexural fatigue of plain and fiber-reinforced concrete with a probabilistic model (Saucedo, Yu, Medeiros, Zhang and Ruiz, Int. J. Fatigue, 2013, 48, 308–318). This model was validated for compressive fatigue at various loading frequencies, but not for flexural fatigue. Since the model is probabilistic, it is not necessarily related to the specific mechanism of fatigue damage, but rather generically explains the fatigue distribution in concrete (plain or reinforced with fibers) for damage under compression, tension or flexion. In this work, more than 100 series of flexural fatigue tests in the literature are fit with excellent results. Since the distribution of monotonic tests was not available in the majority of cases, a two-step procedure is established to estimate the model parameters based solely on fatigue tests. The coefficient of regression was more than 0.90 except for particular cases where not all tests were strictly performed under the same loading conditions, which confirms the applicability of the model to flexural fatigue data analysis. Moreover, the model parameters are closely related to fatigue performance, which demonstrates the predictive capacity of the model. For instance, the scale parameter is related to flexural strength, which improves with the addition of fibers. Similarly, fiber increases the scattering of fatigue life, which is reflected by the decreasing shape parameter.Ministerio de Economía y Competitividad BIA2016-75431-RMinisterio de Economía y Competitividad BIA2015-68678-C2-1-RJunta de Comunidades de Castilla-La Mancha PEII-2014-016-
Antioxidant activity of hydroxytyrosol in frankfurters enriched with n-3 polyunsaturated fatty acids
8 páginas,6 tablas.The capacity of hydroxytyrosol (HXT) to inhibit lipid oxidation in cooked pork meat batter, oil-in-water
emulsions and potential functional frankfurters formulated with a healthier oil combination (as animal
fat replacer) was studied during chilling storage, and its effect compared with those produced by synthetic
antioxidants (BHA/BHT). Although efficiency varied, HXT was an effective antioxidant during chilling
storage in the three food matrices studied. In general the order of inhibition capacity of HXT against
lipid oxidation (thiobarbituric acid-reactive substances-TBARS) was cooked meat batter > oil-in-water
emulsion > frankfurters, whereas in the case of BHA/BHT (with lower inhibitory activity than HXT) it
was cooked meat batter > oil-in-water emulsion, and there was no antioxidative effect in frankfurters.
Whereas significant correlations were established between lipid oxidation (TBARS) and antioxidative
capacity measured by photochemiluminescence (PCL) in frankfurters supplemented with HXT and
BHA/BHT, no significant correlations were found between ferric reducing/antioxidant power assay (FRAP)
and TBARS and PCL.This research was supported by the projects AGL2008-04892-
CO3-01 and Consolider Ingenio 2010: CARNISENUSA (CSD2007-
00016).Peer reviewe
Diagnosing shock temperature with NH and HO profiles
In a previous study of the L1157 B1 shocked cavity, a comparison between
NH(1-) and HO(1--1) transitions showed a
striking difference in the profiles, with HO emitting at definitely higher
velocities. This behaviour was explained as a result of the high-temperature
gas-phase chemistry occurring in the postshock gas in the B1 cavity of this
outflow. If the differences in behaviour between ammonia and water are indeed a
consequence of the high gas temperatures reached during the passage of a shock,
then one should find such differences to be ubiquitous among chemically rich
outflows. In order to determine whether the difference in profiles observed
between NH and HO is unique to L1157 or a common characteristic of
chemically rich outflows, we have performed Herschel-HIFI observations of the
NH(1-0) line at 572.5 GHz in a sample of 8 bright low-mass outflow
spots already observed in the HO(1--1) line within
the WISH KP. We detected the ammonia emission at high-velocities at most of the
outflows positions. In all cases, the water emission reaches higher velocities
than NH, proving that this behaviour is not exclusive of the L1157-B1
position. Comparisons with a gas-grain chemical and shock model confirms, for
this larger sample, that the behaviour of ammonia is determined principally by
the temperature of the gas.Comment: Accepted for publication in the Monthly Notices of the Royal
Astronomical Societ
Natural radiactivity from building materials in Spain
The industrial construction sector is very important in Spain. Building materials used in this industry are sources of radiation from natural radionuclides they contain. The European Commission published some recommendations to facilitate the trade of these materials in the E.U. The studies about this subject have increased notably during last years. This, probably, can be associated with the increase interest from natural radiation radiological risk on indoor exposure.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Consejo de Seguridad Nuclear. CSN-201
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