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The primary objectives of the ExoplANETS-A project are to: establish new knowledge on exoplanet atmospheres; establish new insight on influence of the host star on the planet atmosphere; disseminate knowledge, using online, web-based platforms. The project, funded under the EU’s Horizon-2020 programme, started in January 2018 and has a duration ∼3 years. We present an overview of the project, the activities concerning the host stars and some early results on the host stars.
Phenological and aerobiological research into major crops is of great value in adapting traditional processes to the new conditions prompted by global climate change. Data on flowering phenology and airborne pollen have also proved useful for harvest forecasting purposes. The current paper reports on an agrometeorological study carried out in the Montilla-Moriles Protected Designation of Origin area (Córdoba, southern Spain) in 2015 and 2016. The study focused on four grape cultivars produced at seven local vineyards (Pedro Ximénez, the most widely grown in the area; Verdejo; Muscat blanc à petits grains; and Chardonnay, which has been recently introduced). Phenological observations were performed on a weekly basis using the Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie scale adapted for grapevine. Airborne pollen concentrations were monitored using one Hirst-type volumetric sampler and seven passive samplers. Airborne pollen was mainly detected in vineyards during inflorescence emergence and flowering. Year-on-year differences in climatic conditions led to differences in airborne pollen levels. The main variables affecting pollen concentrations were dew point and temperature. The life-cycles recorded here were shorter than in temperate climates but longer than in tropical climates. In terms of flowering period, the cultivars studied here were classed as ‘early cultivars’. Data obtained using local passive samplers located directly in the vineyard confirmed that the airborne pollen concentrations recorded by the volumetric sampler were representative of the study area.
Energy reserve, estimated as body condition score (BCS), is the major determinant of the re-initiation of ovarian activity in postpartum cows. Leptin, IGF-I and insulin are positively related to BCS and are putative mediators between BCS and reproductive function. However, when BCS and body composition dissociates, concentrations of these metabolic hormones are altered. We hypothesized that increasing lean muscle tissue, but not fat tissue, would diminish the reproductive response to oestrus induction treatments. Thirty lactating beef cows with BCS of 3.10±1.21 and 75.94±12 days postpartum were divided in two groups. Control cows (n=15) were supplemented with 10.20 kg of concentrate daily for 60 days. Treated cows (n=15) were supplemented equally, and received a β-adrenergic receptor agonist (β-AA; 0.15 mg/kg BW) to achieve accretion of lean tissue mass and not fat tissue mass. Twelve days after ending concentrate supplementation/β-AA treatment, cows received a progestin implant to induce oestrus. Cows displaying oestrus were inseminated during the following 60 days, and maintained with a fertile bull for a further 21 days. Cows in both groups gained weight during the supplementation period (Daily weight gain: Control=0.75 kg v. β-AA=0.89 kg). Cows treated with β-AA had a larger increase in BCS (i.e. change in BCS: control=1 point (score 4.13) v. β-AA=2 points (score 5.06; P<0.05), as a result of muscle accretion (i.e. change in muscle depth: control 0.21 cm v. β-AA 0.97 cm; P<0.05) but not adipose tissue (i.e. change in back fat depth; control 0.13 cm v. β-AA −0.06 cm; P<0.05). The changes in body composition in β-AA cows were associated with a reduction in serum concentrations of IGF-I (25.4%) and leptin (27.9%), without observed changes in insulin. Ovulation and pregnancy to 1st service (P>0.05) did not differ between groups. However, the number of cows displaying oestrus (control 13/15 v. β-AA 8/15; P<0.05) and the percentage cycling (control 6/8 v. β-AA 3/10; P=0.07) after progestin treatment and the pregnancy percentage at the end of the breeding period (control 13/15 v. β-AA 8/15; P<0.05) were lower in β-AA than control cows. In summary, the increase BCS through muscle tissue accretion, but not through fat tissue accretion, resulted in a lower response to oestrus induction, lower percentage of cycling animals and lower pregnancy percentage after progestin treatment; which was associated with a decrease in serum concentrations of leptin and IGF-I.
The highlight of this work is the synthesis of copper sulfide nanocrystals by a simple one-pot colloidal process, and the study of its electrochemical, electrical and morphological properties. Nanocrystals of Cu1.8S of about 15-30 nm were obtained at a temperature of 240°C under an argon atmosphere. The colloidal solution of the nanocrystals was analyzed by cyclic voltammetry. Agreeing to the values of EOx and ERedvs. SCE, and the average of three samples the HOMO and LUMO levels are 6.16 and 4.27 eV, respectively, the calculated HOMO – LUMO (Eg) is 1.89 eV. The Eg value, differs of that value obtained from Kubelka-Munk equation (1.7 eV). The photocurrent vs. time results showed that the Cu1.8S/Cu junction is photosensitive and could be used as absorbing material. The morphology and the topography of the film were analyzed by SEM and AFM techniques. Irregular agglomeration of nanocrystals was observed and a roughness of about 194 nm.
Nanomedicine is fostering significant advances in the development of platforms for early detection and treatment of diseases. Nanoparticles (NPs) like quantum dots (QDs) exhibit size-dependent optical properties for light-driven technologies, which might become important in bio-imaging, sensing and photo-dynamic therapy (PDT) applications. The present research addresses the synthesis of water-stable Cd-based QDs via a Microwave-Assisted synthesis approach using cadmium sulfate salt, and thioglycolic acid as Cd- and S-precursors, respectively. Selenide ions were available by reductive leaching of metallic Selenium in Sodium bisulfite solution. The size control and the tunability of the optical properties were achieved by a suitable control of the reaction temperature (in the 140°C- 190°C range) and reaction time (10 minutes-40 minutes). X-ray diffraction analyses suggested the development of a CdSe,S face cubic centered structure; the broadening of the diffraction peaks indicated the presence of very small nanocrystals in the samples. The average crystallite size was estimated at 5.50 nm ± 1.17nm and 3.72 nm ± 0.04 nm, for nanoparticles synthesized at 180°C after 40 minutes or 10 minutes of reaction, respectively. HRTEM images confirmed the crystalline nature and the small size of the synthesized nanocrystals. In turn, the exciton was red-shifted from 461nm to 549 nm when the reaction temperature was prolonged from 140°C to 190 °C, suggesting the crystal growth. The corresponding band gap values were approximately 2.2 eV, confirming the quantum confinement effect (bulk value 1.74eV). This red shift was also evidenced in PL measurements where the main emission peak was shifted from 507 nm to 564 nm when the samples were excited at 420 nm. A narrow size-tunable emission also was supported by the full width at half maximum (∼ 45 nm) for the synthesized nanocrystals. The reactive oxygen species generation capability of as-synthesized QDs was also investigated. The correlation between the particle size and the generation of (ROS) by the degradation of methylene blue was evident with a reduction of MB concentration from 10μM to 7.5μM and 6.7μM after 15 minutes of UV irradiation for reaction time of 10 min. and 40 min. respectively. No additional degradation was noticed after 60 minutes of irradiation.
Background: Percutaneous closure of patent ductus arteriosus has become the treatment of choice in many centres. In patients with large ducts and pulmonary hypertension, transcatheter closure has been achieved with success using the Amplatzer Duct Occluder or even the Amplatzer Muscular Ventricular Septal Defect Occluder. Materials and methods: We present a series of 17 patients with large and hypertensive ductus arteriosus who were treated with an Amplatzer Septal Occluder. The group had 11 female patients (64.7%) and a mean age of 18.6±12.1 years. Results: The haemodynamic and anatomical data are as follows: pulmonary artery systolic pressure 71.3±31.8 mmHg, pulmonary to systemic flow ratio 3.14±1.36, ductal diameter at the pulmonary end 12.5±3.8 mm, and at the aortic end 20.2±7.7 mm; 14 cases (82.3%) had type A ducts. In 11 patients, we began the procedure using a different device – six with duct occluder and five with ventricular septal occluder – and it was changed because of device embolisation in six (35.3%). All septal occluders were delivered successfully. Residual shunt was moderate in six patients (35.3%), mild in eight (47%), trivial in two (11.8%), and no shunt in one (5.9%). Pulmonary systolic pressure decreased to 48.9±10.8 mmHg after occlusion (p=0.0015). Follow-up in 15 patients (88.2%) for 28.4±14.4 months showed complete closure in all cases but one, and continuous decrease of the pulmonary systolic pressure to 31.4±10.5 mmHg. No complications at follow-up have been reported. Conclusions: The Amplatzer Septal Occluder is a good alternative to percutaneously treat large and hypertensive ductus arteriosus.
Rocks are composed of minerals, bounding matrix, cracks and pores. The study of changes in the physical properties of rocks as a function of heat treatment is relevant to various engineering and industrial applications. The effect of thermal damage on the compression, strength, ultimate compression strain, color and loss of mass of two different limestones extracted from the Yucatan Peninsula is studied. Different thermal treatments are applied by heating the sample from room temperature up to 600°C, with steps of 100°C. The results show a high correlation between the heat transport characteristics, mechanical properties, content of organic matter and the presence of carbonates and iron oxides in each type of limestone rock.
In many tropical countries coconut (coir) fiber production is a major source of income for rural communities. The Caribbean has an abundance of coconuts but research into utilizing its by-products is limited. Environmentally friendly coir fibers are natural polymers generally discarded as waste material in this region. Research has shown that coir fiber from other parts of the world has successfully been recycled. This paper therefore investigates the mechanical properties of Caribbean coir fiber for potential applications in civil engineering.
Approximately four hundred fibers were randomly taken from a coir fiber stack and subjected to retting in both distilled and saline water media. The mechanical properties of both the retted and unretted coir fibers were evaluated at weekly increments for a period of 3 months. Tensile strength test, x-ray diffraction analysis and scanning electron micrographs were used to assess trends and relationships between fiber gauge lengths, diameter, tensile strength and Young’s modulus. Diameters ranged between 0.11 mm-0.46 mm, while fiber samples were no longer than 250 mm in length. The tensile strength and strain at break decreased as the gauge length increased for both unretted and retted fibers. The opposite occurred for the relationship between the gauge length and Young’s modulus. Additionally, the tensile strength and modulus decreased as the fiber diameter increased. Neither distilled nor saline water improved the coir fiber’s crystalline index. Scanning electron micrographs qualitatively assessed fiber surfaces and captured necking and microfibril degradation at the fractured ends.
The analysis revealed that the tensile strength, modulus, strain at break and crystallinity properties of the Caribbean coir fibers were comparable to commercially available coir fiber which are currently being used in many building applications.
The Vista Variables in the Vía Láctea (VVV) ESO Public Survey is an ongoing time-series, near-infrared (IR) survey of the Galactic bulge and an adjacent portion of the inner disk, covering 562 square degrees of the sky, using ESO's VISTA telescope. The survey has provided superb multi-color photometry in 5 broadband filters (Z, Y, J, H, and Ks), leading to the best map of the inner Milky Way ever obtained, particularly in the near-IR. The main part of the survey, which is focused on the variability in the Ks-band, is currently underway, with bulge fields observed between 34 and 73 times, and disk fields between 34 and 36 times. When the survey is complete, bulge (disk) fields will have been observed up to a total of 100 (60) times, providing unprecedented depth and time coverage in the near-IR. Here we provide a first overview of stellar variability in the VVV data.
Knowledge of the mechanical and petrographic properties of limestone rocks is an important issue to different areas of science and engineering. Sedimentary limestone rock is one of the most abundant materials in the Peninsula of Yucatán used for decorative and building construction. This work studies the petrographic, mineralogical, and physical properties of three different types of limestone slabs of the state of Yucatán.
Tantalum carbide is a technologically important material for use in ultra-high temperatures and corrosive environments. In this report, we describe the scalability of a low temperature solvothermal method for the preparation of this useful material. X-ray diffraction shows phase-pure powders with no change in average crystallite size or compound stoichiometry compared to synthesis in smaller batches, remaining at 25 nm and 0.94 respectively. Dynamic light scattering shows a slight decrease in particle size distribution with scale-up. Thermogravimetric analysis (TGA) in air shows a decrease in surface species on the powders, but the powders oxidize at a lower temperature when scaling the synthesis. Mass spectrometry performed alongside TGA in a helium atmosphere reveals that water is the most abundant species on the surface of the powders, but oxygen, carbon monoxide, carbon dioxide, and nitrogen are also detected. Oxygen analysis reveals that the oxygen content of the powders is high (>6%). The oxygen source and methods of decreasing oxygen content are discussed. Initial sintering trials were performed and demonstrate the need for further powder processing.
Optimum machining parameters are of great concern in manufacturing environments, where economy of machining operation plays a key role in competitiveness in the market. Many researchers have dealt with the optimization of machining parameters for milling operations. In this paper, optimization procedures based on particle swarm optimization algorithm are developed for find machining parameters in milling operation. It describes development and utilization of the methodology that determines optimum Pareto’s front analyzing feed, speed and depth for milling operation. The relationships between machining parameters and the performance measures of interest are obtained by using experimental data and a swarm intelligent neural network system. Results show that particle swarm optimization is an effective method for solving multi-objective optimization problems, and also, that an integrated system of neural networks and swarm intelligence can be used to solve complex machining optimization problems.
The phase formation in the zone of directional laser irradiation of compacted Al2O3–TiO2–Y2O3 mixtures has been investigated. It is established that phase formation is carried out within the framework of binary mixtures Al2O3 – Y2O3 and Y2O3 – TiO2.
The sintering of tantalum carbide nanopowders by spark plasma sintering (SPS) is investigated. The washing procedure for the powders is modified from previous work to eliminate excess lithium in the powders that is left over from the synthesis process. The sintering behavior of the nanopowders is investigated by X-ray diffraction and scanning electron microscopy by studying specimens that were sintered to different temperatures. To improve the homogeneity of the microstructure of the specimens, milling procedures were implemented. Vaporization during sintering is observed, and the usefulness of carbon additions and systematic decreases in temperature to curb this behavior was explored. Future experiments to achieve full density and to maintain a nanostructure of the specimens include sintering with higher pressures, lower temperatures, and longer dwell times. Additives for maintaining a nanostructure and developing suitable high-temperature properties are also discussed.
A sample of ~150 compact Galactic PNe has been observed with the Spitzer/IRS spectrograph to characterize their dust properties. These PNe are likely to be at the onset of the PN evolutionary phase, and are therefore ideal for probing dust evolution. The molecular emission features in these Galactic PN spectra are similar to those found in our Magellanic Cloud sample, except that we found a sizable fraction of PNe with mixed-chemistry dust which are not observed in the Clouds. We also found that the distribution among dust types depends strongly on the metallicity of the parent population, implying that the metallicity of the progenitors affects the evolution of a PN from its early stages.