752 research outputs found
Vibrational spectroscopic studies on crystallisation of sol-gel derived thin films of calcia-alumina binary compound
An optimized sol-gel process has been developed to produce homogeneous thin films of calcium aluminate binary (12CaO·7Al2O3) compound, on magnesium oxide substrates via spin coating. Fourier transform infrared and Raman spectroscopies have been employed to investigate the effect of annealing temperature and duration on the phase transformations in the films. Heat treatment at 1,300 °C under air atmosphere for 2 h produced single-phase 12CaO·7Al2O3 films. However, annealing at a lower temperature of 1,100 °C in air for a period of 4 h in total resulted in the crystallization of 5CaO·3Al2O3 rather than 12CaO·7Al2O3. The X-ray photoelectron spectrum of the thin film annealed at 1,300 °C corresponds to the binding energies of C12A7 compound. The annealing temperature of 1,300 °C for 2 h is found to be sufficient for formulating single phase calcia-alumina binary films in correct stoichiometric ratio of 12:7. © 2014 Springer Science+Business Media New York
Teachers’ Adoption of Embodied Learning Digital Games with an Inclusive Education Approach: Lessons Learnt from the INTELed Project in Spain
Producción CientíficaEmbodied learning digital games have been used with success in the past to support students with special education needs, but their application by teachers in mainstream classes with an inclusive approach is still a challenge. This paper presents the results of a set of pilots in which a suite of embodied digital games was applied into pre-school and primary school classrooms. The findings of the studies provide insights into the conditions that facilitated and/or impeded the adoption of the technology by the participant teachers. These results are then elaborated to define a first set of strategies that could be used by third-party teachers to fulfill the same objectives, and to identify concrete design challenges for the application of embodied digital games in classrooms.Ministerio de Ciencia, Innovación y Universidades (Project TIN2017-85179-C3-2-R)Junta de Castilla y León (Project VA257P18 (CASSUALearn
Developments in the study and applications of bacterial transformations of selenium species
Microbial bio-transformations of the essential trace element selenium are now recognized to occur among a wide variety of microorganisms. These transformations are used to convert this element into its assimilated form of selenocysteine, which is at the active center of a number of key enzymes, and to produce selenium nanoparticles, quantum dots, metal selenides, and methylated selenium species that are indispensable for biotechnological and bioremediation applications. The focus of this review is to present the state-of-the-art of all aspects of the investigations into the bacterial transformations of selenium species, and to consider the characterization and biotechnological uses of these transformations and their products
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Spectroscopic and Microscopic Characterization of Microbial Biofouling on Aircraft Fuel Tanks
Full text also available at: Europe PMC - https://europepmc.org/article/MED/38319653Avoiding microbial contamination and biofilm formation on the surfaces of aircraft fuel tanks is a major challenge in the aviation industry. The inevitable presence of water in fuel systems and nutrients provided by the fuel makes an ideal environment for bacteria, fungi, and yeast to grow. Understanding how microbes grow on different fuel tank materials is the first step to control biofilm formation in aviation fuel systems. In this study, biofilms of Pseudomonas putida, a model Gram-negative bacterium previously found in aircraft fuel tanks, were characterized on aluminum 7075-T6 surfaces, which is an alloy used by the aviation industry due to favorable properties including high strength and fatigue resistance. Scanning electron microscopy (SEM) coupled with energy-dispersive X-ray (EDX) showed that extracellular polymeric substances (EPS) produced by P. putida were important components of biofilms with a likely role in biofilm stability and adhesion to the surfaces. EDX analysis showed that the proportion of phosphorus with respect to nitrogen is higher in the EPS than in the bacterial cells. Additionally, different morphologies in biofilm formation were observed in the fuel phase compared to the water phase. Micro-Fourier transform infrared spectroscopy (micro-FTIR) analysis suggested that phosphoryl and carboxyl functional groups are fundamental for the irreversible attachment between the EPS of bacteria and the aluminum surface, by the formation of hydrogen bonds and inner-sphere complexes between the macromolecules and the aluminum surface. Based on the hypothesis that nucleic acids (particularly DNA) are an important component of EPS in P. putida biofilms, the impact of degrading extracellular DNA was tested. Treatment with the enzyme DNase I affected both water and fuel phase biofilms─with the cell structure disrupted in the aqueous phase, but cells remained attached to the aluminum coupons.InnovateUK and Airbus Operations Ltd., within the project “Fuel Architecture and Systems Technology (FAST)”, Project reference 113161 (TS/R008132/1). A.D.M. acknowledges funding from the UK Engineering and Physical Sciences Research Council (EPSRC) DTP scholarship (project reference: 2748843
Nadroparine-induced skin necrosis on a patient with essential thrombocythaemia: a case report
Skin necrosis is a rare but serious complication of subcutaneously administered low-molecular-weight heparin. We report a case of a 53-year-old female patient with skin necrosis induced by subcutaneous administration of nadroparine. The patient suffered from essential thrombocythaemia on a background of chronic myeloproliferative disease. She was admitted to our clinic with a subacute ileus due to endometriosis of the rectosigmoid junction. She underwent a high anterior resection and she received pre- and postoperative antithrombotic prophylaxis with subcutaneous nadroparine on a daily basis. On the 6th and 7th postoperative days, two skin necroses occurred at two injection sites
Drawing Boundaries
In “On Drawing Lines on a Map” (1995), I suggested that the different ways we have of drawing lines on maps open up a new perspective on ontology, resting on a distinction between two sorts of boundaries: fiat and bona fide. “Fiat” means, roughly: human-demarcation-induced. “Bona fide” means, again roughly: a boundary constituted by some real physical discontinuity. I presented a general typology of boundaries based on this opposition and showed how it generates a corresponding typology of the different sorts of objects which boundaries determine or demarcate. In this paper, I describe how the theory of fiat boundaries has evolved since 1995, how it has been applied in areas such as property law and political geography, and how it is being used in contemporary work in formal and applied ontology, especially within the framework of Basic Formal Ontology
Alignment of the stellar spin with the orbits of a three-planet system
The Sun’s equator and the planets’ orbital planes are nearly aligned, which is presumably a consequence of their formation from a single spinning gaseous disk. For exoplanetary systems this well-aligned configuration is not guaranteed: dynamical interactions may tilt planetary orbits, or stars may be misaligned with the protoplanetary disk through chaotic accretion1 , magnetic interactions[superscript 2] or torques from neighbouring stars. Indeed, isolated ‘hot Jupiters’ are often misaligned and even orbiting retrograde[superscript 3, 4]. Here we report an analysis of transits of planets over starspots[superscript 5, 6, 7] on the Sun-like star Kepler-30 (ref. 8), and show that the orbits of its three planets are aligned with the stellar equator. Furthermore, the orbits are aligned with one another to within a few degrees. This configuration is similar to that of our Solar System, and contrasts with the isolated hot Jupiters. The orderly alignment seen in the Kepler-30 system suggests that high obliquities are confined to systems that experienced disruptive dynamical interactions. Should this be corroborated by observations of other coplanar multi-planet systems, then star–disk misalignments would be ruled out as the explanation for the high obliquities of hot Jupiters, and dynamical interactions would be implicated as the origin of hot Jupiters.United States. National Aeronautics and Space Administration (Science MissionDirectorate
A rocky composition for an Earth-sized exoplanet
Planets with sizes between that of Earth (with radius R[subscript circle in cross]) and Neptune (about 4 R[subscript circle in cross]) are now known to be common around Sun-like stars. Most such planets have been discovered through the transit technique, by which the planet’s size can be determined from the fraction of starlight blocked by the planet as it passes in front of its star. Measuring the planet’s mass—and hence its density, which is a clue to its composition—is more difficult. Planets of size 2–4 R[subscript circle in cross] have proved to have a wide range of densities, implying a diversity of compositions, but these measurements did not extend to planets as small as Earth. Here we report Doppler spectroscopic measurements of the mass of the Earth-sized planet Kepler-78b, which orbits its host star every 8.5 hours (ref. 6). Given a radius of 1.20 ± 0.09 R[subscript circle in cross] and a mass of 1.69 ± 0.41 M[subscript circle in cross], the planet’s mean density of 5.3 ± 1.8 g cm[superscript −3] is similar to Earth’s, suggesting a composition of rock and iron.Kepler Participating Scientist Progra
Midday measurements of leaf water potential and stomatal conductance are highly correlated with daily water use of Thompson Seedless grapevines
A study was conducted to determine the relationship between midday measurements of vine water status and daily water use of grapevines measured with a weighing lysimeter. Water applications to the vines were terminated on August 24th for 9 days and again on September 14th for 22 days. Daily water use of the vines in the lysimeter (ETLYS) was approximately 40 L vine−1 (5.3 mm) prior to turning the pump off, and it decreased to 22.3 L vine−1 by September 2nd. Pre-dawn leaf water potential (ΨPD) and midday Ψl on August 24th were −0.075 and −0.76 MPa, respectively, with midday Ψl decreasing to −1.28 MPa on September 2nd. Leaf g s decreased from ~500 to ~200 mmol m−2 s−1 during the two dry-down periods. Midday measurements of g s and Ψl were significantly correlated with one another (r = 0.96) and both with ETLYS/ETo (r = ~0.9). The decreases in Ψl, g s, and ETLYS/ETo in this study were also a linear function of the decrease in volumetric soil water content. The results indicate that even modest water stress can greatly reduce grapevine water use and that short-term measures of vine water status taken at midday are a reflection of daily grapevine water us
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