844 research outputs found
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ORIGAMI-SCISSOR Hinged Geometry Method
The diamond origami-scissor hinged pattern marks a new type of thick origami that can not only fold and unfold, but also expand and contract (project below). This was done by applying the ‘form generation method of relative ratios’ for two-bar scissors to the thick origami. This research tests whether this method can be extended and generalized to other types of origami. The origami-scissor hinged geometry method is here applied to the waterbomb of thick panels making a waterbomb origami-scissor hinged pattern. While the waterbomb origami of thick panels has one degree of freedom, the waterbomb origami-scissor hinged pattern has two degrees of freedom as it can independently fold and unfold as an origami, and expand and contract as a scissor hinged structure. This creates a new research branch of expandable thick origami.
The ‘form generation method of relative ratios’ (FGMORR) [Rivas-Adrover 17] has been applied to the ‘origami of thick panels’ [Chen et al. 15] because this method to make thick origami can be extended and generalized to different types of origami, and therefore the origami-scissor hinged geometry method can also be applied to all these different types of origami. A critical condition is that the thick
origami has to be made of equal or proportional thicknesses so that when translating that geometry with scissors the end nodes match. Another condition is that the pantographs that mark the creases and join different origami faces must have an equal morphology and bilateral symmetry. Automation of this method will be investigated with Grasshopper for Rhinoceros.
Origami-scissor hinged patterns provide an extra degree of freedom, therefore origami patterns that could be folded can now also contract and occupy much smaller volumes. This would be useful in applications where a high ratio of deployed-to stowed volume is required such as space applications, earthbound transportable applications, and to create adaptable spaces and transformable environments in permanent architecture
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A New Hybrid Type of Deployable Structure: Origami-scissor Hinged
Deployable structures can transform, expand and contract due to their geometric, material and mechanical properties; applications spread across multiple fields including aerospace technology and temporary, mobile and transformable architecture. There are many different types of deployable structures. For instance, the art of origami has developed concepts for paper folds that can expand and contract. Another type is that of scissorhinged structures, made by bars joined by pivots. These two different types, origami and scissors, have so far remained separate types within the field. This geometry research unifies both types and makes an origamiscissor structure, which has a double deployment. This new technology has potential applications in architecture and engineering, such as transportable pavilions, aerospace or robotic applications
CO-PrOx over nano-Au/TiO2: Monolithic catalyst performance and empirical kinetic model fitting
In this work, the performance of ceramic monoliths washcoated with Au/TiO2 is studied on CO preferential oxidation (CO-PrOx) reaction in H2-rich environments under a wide range of operating conditions of practical interest. The parameter estimation of a nonlinear kinetic empirical model representing this system is made via genetic algorithms by fitting the model predictions against our laboratory observations. Parameter uncertainty leading to inaccurate predictions is often present when kinetic models with nonlinear rate equations are considered. Here, after the fitting was concluded, a statistical study was conducted to determine the accuracy of the parameter estimation. Activation energies of ca. 30 kJ/mol and 55 kJ/mol were adjusted for CO and H2 oxidations, respectively. The catalyst showed appropriate activity and selectivity values on the CO oxidation on a H2-rich environment. After ca. 45 h on stream the catalyst showed no deactivation. Results show that the model is suitable for reproducing the behavior of the CO-PrOx reactions and it can be used in the design of reactors for hydrogen purification.Peer ReviewedPostprint (author's final draft
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Classification Of Geometry For Deployable Structures Used For Innovation: Design Of New Surfaces With Scissor 2 Bar, And Form Generation Method Of Relative Ratios
Deployable structures can expand and/or contract due to their geometrical, material and mechanical properties. This research proposes a classification of geometry for deployable structures. This classification system applied to structures made with scissor 2 bar can lead to architectural innovation. This is demonstrated in the case study of a new design for surfaces based on scissors 2 bar. Through this case study a form generation method of relative ratios is formulated that can be applied to infinite geometrical arrangements.
This geometry classification is an attempt to seek further understanding of the subject of deployable structures. In order to gain a comprehensive understanding of this field, different ways of ordering information are being considered
MicromamÃferos vallesienses del yacimiento La Salle en las Arcillas Rojas de Teruel
El hallazgo de unos restos de micromamiferos en las proximidades del Colegio La Salle de Teruel permite datar la formación de las arcillas rojas conocida con 10s nombres de "Los Monotos", "Formación de Los Tejares" y "Pera1 Formation". La ausencia casi total de fósiles ha hecho que la edad de esa formación fuera largamente discutida. Los fósiles recientemente encontrados permiten atribuirle una edad vallesiense (MN 10 basal). La fauna recogida comprende: Galerix (Parasorex) socialis, Crusafontina excultus, Hispanomys peralensis, Progonomys hispanicus, P. cathalai y Prolagus crusafonti, que se Gade a la de Tetralophodon longirostris, e Hippmion sp
Sic1 plays a role in timing and oscillatory behaviour of B-type cyclins
Budding yeast cell cycle oscillates between states of low and high cyclin-dependent kinase activity, driven by association of Cdk1 with B-type (Clb) cyclins. Various Cdk1-Clb complexes are activated and inactivated in a fixed, temporally regulated sequence, inducing the behaviour known as "waves of cyclins". The transition from low to high Clb activity is triggered by degradation of Sic1, the inhibitor of Cdk1-Clb complexes, at the entry to S phase. The G(1) phase is characterized by low Clb activity and high Sic1 levels. High Clb activity and Sic1 proteolysis are found from the beginning of the S phase until the end of mitosis. The mechanism regulating the appearance on schedule of Cdk1-Clb complexes is currently unknown. Here, we analyse oscillations of Clbs, focusing on the role of their inhibitor Sic1. We compare mathematical networks differing in interactions that Sic1 may establish with Cdk1-Clb complexes. Our analysis suggests that the wave-like cyclins pattern derives from the binding of Sic1 to all Clb pairs rather than from Clb degradation. These predictions are experimentally validated, showing that Sic1 indeed interacts and coexists in time with Clbs. Intriguingly, a sic1Delta strain looses cell cycle-regulated periodicity of Clbs, which is observed in the wild type, whether a SIC1-0P strain delays the formation of Clb waves. Our results highlight an additional role for Sic1 in regulating Cdk1-Clb complexes, coordinating their appearance
Are T Tauri stars gamma-ray emitters?
T Tauri stars are young, low mass, pre-main sequence stars surrounded by an
accretion disk. These objects present strong magnetic activity and powerful
magnetic reconnection events. Strong shocks are likely associated with fast
reconnection in the stellar magnetosphere. Such shocks can accelerate particles
up to relativistic energies. We aim at developing a simple model to calculate
the radiation produced by non-thermal relativistic particles in the environment
of T Tauri stars. We want to establish whether this emission is detectable at
high energies with the available or forthcoming gamma-ray telescopes. We assume
that particles (protons and electrons) pre-accelerated in reconnection events
are accelerated at shocks through Fermi mechanism and we study the high-energy
emission produced by the dominant radiative processes. We calculate the
spectral energy distribution of T Tauri stars up to high-energies and we
compare the integrated flux obtained with that from a specific Fermi source,
1FGL J1625.8-2429c, that we tentatively associate with this kind of young
stellar objects (YSOs). We suggest that under reasonable general conditions
nearby T Tauri stars might be detected at high energies and be responsible for
some unidentified Fermi sources on the Galactic plane.Comment: 7 pages, 10 figure
Binaries with the eyes of CTA
The binary systems that have been detected in gamma rays have proven very
useful to study high-energy processes, in particular particle acceleration,
emission and radiation reprocessing, and the dynamics of the underlying
magnetized flows. Binary systems, either detected or potential gamma-ray
emitters, can be grouped in different subclasses depending on the nature of the
binary components or the origin of the particle acceleration: the interaction
of the winds of either a pulsar and a massive star or two massive stars;
accretion onto a compact object and jet formation; and interaction of a
relativistic outflow with the external medium. We evaluate the potentialities
of an instrument like the Cherenkov telescope array (CTA) to study the
non-thermal physics of gamma-ray binaries, which requires the observation of
high-energy phenomena at different time and spatial scales. We analyze the
capability of CTA, under different configurations, to probe the spectral,
temporal and spatial behavior of gamma-ray binaries in the context of the known
or expected physics of these sources. CTA will be able to probe with high
spectral, temporal and spatial resolution the physical processes behind the
gamma-ray emission in binaries, significantly increasing as well the number of
known sources. This will allow the derivation of information on the particle
acceleration and emission sites qualitatively better than what is currently
available.Comment: 23 pages, 13 figures, accepted for publication in Astroparticle
Physics, special issue on Physics with the Cherenkov Telescope Arra
A study of the association of Fermi sources with massive young galactic objects
Massive protostars have associated bipolar outflows that can produce strong shocks when they interact with the surrounding medium. At these shocks particles can be accelerated up to relativistic energies. Relativistic electrons and protons can then produce gamma-ray emission, as some theoretical models predict. To identify young galactic objects that may emit gamma rays, we crossed the Fermi First Year Catalog with some catalogs of known massive young stellar objects (MYSOs), early type stars, and OB associations, and we implemented Monte Carlo simulations to find the probability of chance coincidences. We obtained a list of massive MYSOs that are spatially coincident with Fermi sources. Our results indicate that \sim 70% of these candidates should be gamma-ray sources with a confidence of \sim 5{\sigma}. We studied the coincidences one by one to check the viability of these young sources as potential counterparts to Fermi sources and made a short list of best targets for new detailed multifrequency observations. The results for other type of young galactic objects are not conclusive
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