There is an acknowledged need for shaping 3-D scaffolds with adequate porosity and mechanical properties for biomedical applications. The mechanical properties under static and cyclic compressive ...testing of dense and designed porous architecture bioceramic scaffolds based on the biphasic calcium phosphate (BCP) systems and BCP–agarose systems have been evaluated. The dense and designed porous architecture scaffolds in BCP systems exhibited a brittle behaviour. Agarose, a biocompatible and biodegradable hydrogel, has been used to shape designed architecture ceramic–agarose scaffolds following a low-temperature shaping method. Agarose conferred toughness, ductility and a rubbery consistency for strains of up to 60% of in ceramic BCP–agarose systems. This combination of ceramic and organic matrix helps to avoid the inherent brittleness of the bioceramic and enhances the compression resistance of hydrogel. The presence of mechanical hysteresis, permanent deformation after the first cycle and recovery of the master monotonous curve indicate a Mullins-like effect such as that observed in carbon-filled rubber systems. We report this type of mechanical behaviour, the Mullins effect, for the first time in bioceramics and bioceramic–agarose systems.
HH 110 is a rather peculiar HerbigHaro object in Orion that originates due to the deflection of another jet (HH 270) by a dense molecular clump, instead of being directly ejected from a young stellar ...object. Here we present new results on the kinematics and physical conditions of HH 110 based on Integral Field Spectroscopy. The 3D spectral data cover the whole outflow extent (∼4.5 arcmin, ≃0.6 pc at a distance of 460 pc) in the spectral range 6500–7000 Å. We built emission-line intensity maps of Hα, N ii and S ii and of their radial velocity channels. Furthermore, we analysed the spatial distribution of the excitation and electron density from N ii/Hα, S ii/Hα and S ii 6716/6731 integrated line-ratio maps, as well as their behaviour as a function of velocity, from line-ratio channel maps. Our results fully reproduce the morphology and kinematics obtained from previous imaging and long-slit data. In addition, the integral field spectroscopy (IFS) data revealed, for the first time, the complex spatial distribution of the physical conditions (excitation and density) in the whole jet, and their behaviour as a function of the kinematics. The results here derived give further support to the more recent model simulations that involve deflection of a pulsed jet propagating in an inhomogeneous ambient medium. The IFS data give richer information than that provided by current model simulations or laboratory jet experiments. Hence, they could provide valuable clues to constrain the space parameters in future theoretical works.
The current validated endotoxin detection methods, in spite of being highly sensitive, present several drawbacks in terms of reproducibility, handling and cost. Therefore novel approaches are being ...carried out in the scientific community to overcome these difficulties. Remarkable efforts are focused on the development of endotoxin-specific biosensors. The key feature of these solutions relies on the proper definition of the capture protocol, especially of the bio-receptor or ligand. The aim of the presented work is the screening and selection of a synthetic peptide specifically designed for LPS detection, as well as the optimization of a procedure for its immobilization onto gold substrates for further application to biosensors.
•A study of the thermal performance of a solar-only direct steam generation Linear Fresnel power plant has been performed.•The off-design performance of the solar field and power block have been ...simulated.•The solar field size and the storage capacity have been varied to study their contribution in the annual electricity yield.•The solar multiple and energy storage capacity that minimize the Levelized Cost of Electricity have been determined.
Linear Fresnel power plants are currently one of the most promising concentrating solar power plants. However there are only a few commercial projects. These power plants have a lower efficiency than parabolic trough collector plants and are still expensive. To increase the efficiency of these plants, the utilization of water/steam in the receivers (direct steam generation, DSG) and thermal storage (TES) have been considered.
As case study, a 50MWe solar-only linear Fresnel power plant located in Seville, Spain is considered. The effects of the solar field size and the thermal storage size on the annual production of the plant are analyzed: Nine different solar field sizes and up to eight thermal storage sizes have been compared.
An economic optimization is presented in order to determine which plant has lowest Levelized Cost of Electricity (LCOE). It has been found that for the power plants with no-storage the optimum solar multiple (SM) is 1.7, whereas for the cases with thermal storage, the optimum configuration is a larger solar field (SM = 2), with a thermal storage of 2 h.
Introduction Directed by Edward Zwick “Pawn Sacrifice” is a biographical film released on September 2015. The film stars Tobey Maguire as Bobby Fischer, the American World Chess Champion, considered ...one of greatest player of all time. His career's peak was in 1972 when he captured the World Chess Championship from Boris Spassky of the USSR. Aims We tried to dig a little in the biography of Bobby Fischer who many described as mentally ill. We tried to figure out what is reality and what is just legend about Fischer. Our goal is promote chess, and also honour the great Fischer. Moreover, we wanted to explore the scientific literature published about the benefits of playing chess, especially in childhood. Methods We made an exhaustive review of the author's life, and also testimonies of people who knew him. Moreover, we found some articles that review the relationship between chess and IQ trying to confirm or debunk some myths about this legendary game. Results It was incomprehensible to everyone that the top of the career of Bobby Fischer at the same time meant an abrupt and complete fall. One possible explanation for this attitude would be a mentally unbalance not specified disorder throughout his lifespan. Conclusions Not all geniuses are crazy, neither all crazy are geniuses. A genius is a person with extraordinary capabilities, that focused on a topic, has the ability to enlight new ways to explain this complex world, whether it is to create a symphony, paint masterpiece or the next move on the chessboard.
•The use of a Heller tower as a condensing system in a CSP plant has been analyzed.•The natural draft tower and detailed cycle of the power block have been modeled.•This system increases 6% the ...annual energy production compared to MDDCT.•Water consumption is reduced by more than 1.4 106 m3/year compared to wet towers.•A water cost of more 1.96 $/m3 makes the Heller system profitable.
Important efforts are dedicated to reduce water use in the power generation sector. In this paper the use of a dry Heller cooling system is proposed to diminish the water consumption of a concentrated solar tower power plant. The Heller system is an indirect cooling system where the exhaust steam from the turbine is condensed in a direct contact heat exchanger. Part of the condensate and cooling water are pumped to the feed water heaters while the rest is pumped to the dry cooling tower. In this particular case a natural draft dry cooling tower is employed.
The detailed cycle of the power block and the cooling system have been modeled. The results indicate an increase of the energy production by almost 6% compared to a mechanically draft dry cooling system and a reduction of the annual energy production of less than 3.7% compared to a wet cooling system. Furthermore, it has been found that this cooling system is able to reduce almost 1.4·106m3 of water per year, which makes it an attractive choice especially in arid regions.
A cost model has been presented to determine the equivalent water price that makes profitable the use a Heller system (Water price =1.96$/m3).
The use of 3D scaffolds based on mesoporous bioactive glasses (MBG) enhanced with therapeutic ions, biomolecules and cells is emerging as a strategy to improve bone healing. In this paper, the ...osteogenic capability of ZnO-enriched MBG scaffolds loaded or not with osteostatin (OST) and human mesenchymal stem cells (MSC) was evaluated after implantation in New Zealand rabbits. Cylindrical meso-macroporous scaffolds with composition (mol %) 82.2SiO
2
–10.3CaO–3.3P
2
O
5
–4.2ZnO (4ZN) were obtained by rapid prototyping and then, coated with gelatin for easy handling and potentiating the release of inorganic ions and OST. Bone defects (7.5 mm diameter, 12 mm depth) were drilled in the distal femoral epiphysis and filled with 4ZN, 4ZN + MSC, 4ZN + OST or 4ZN + MSC + OST materials to evaluate and compare their osteogenic features. Rabbits were sacrificed at 3 months extracting the distal third of bone specimens for necropsy, histological, and microtomography (µCT) evaluations. Systems investigated exhibited bone regeneration capability. Thus, trabecular bone volume density (BV/TV) values obtained from µCT showed that the good bone healing capability of 4ZN was significantly improved by the scaffolds coated with OST and MSC. Our findings in vivo suggest the interest of these MBG complete systems to improve bone repair in the clinical practice.
The Galactic center supermassive black hole Sagittarius A* (Sgr A*) is one of the most promising targets to study the dynamics of black hole accretion and outflow via direct imaging with very long ...baseline interferometry (VLBI). At 3.5 mm (86 GHz), the emission from Sgr A* is resolvable with the Global Millimeter VLBI Array (GMVA). We present the first observations of Sgr A* with the phased Atacama Large Millimeter/submillimeter Array (ALMA) joining the GMVA. Our observations achieve an angular resolution of ∼87 as, improving upon previous experiments by a factor of two. We reconstruct a first image of the unscattered source structure of Sgr A* at 3.5 mm, mitigating the effects of interstellar scattering. The unscattered source has a major-axis size of 120 34 as (12 3.4 Schwarzschild radii) and a symmetrical morphology (axial ratio of ), which is further supported by closure phases consistent with zero within 3 . We show that multiple disk-dominated models of Sgr A* match our observational constraints, while the two jet-dominated models considered are constrained to small viewing angles. Our long-baseline detections to ALMA also provide new constraints on the scattering of Sgr A*, and we show that refractive scattering effects are likely to be weak for images of Sgr A* at 1.3 mm with the Event Horizon Telescope. Our results provide the most stringent constraints to date for the intrinsic morphology and refractive scattering of Sgr A*, demonstrating the exceptional contribution of ALMA to millimeter VLBI.
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